DOE Office of Scientific and Technical Information (OSTI.GOV)
Lavoie, Caroline; Higgins, Jane; Bissonnette, Jean-Pierre
2012-12-01
Purpose: To compare the relative accuracy of 2 image guided radiation therapy methods using carina vs spine as landmarks and then to identify which landmark is superior relative to tumor coverage. Methods and Materials: For 98 lung patients, 2596 daily image-guidance cone-beam computed tomography scans were analyzed. Tattoos were used for initial patient alignment; then, spine and carina registrations were performed independently. A separate analysis assessed the adequacy of gross tumor volume, internal target volume, and planning target volume coverage on cone-beam computed tomography using the initial, middle, and final fractions of radiation therapy. Coverage was recorded for primary tumormore » (T), nodes (N), and combined target (T+N). Three scenarios were compared: tattoos alignment, spine registration, and carina registration. Results: Spine and carina registrations identified setup errors {>=}5 mm in 35% and 46% of fractions, respectively. The mean vector difference between spine and carina matching had a magnitude of 3.3 mm. Spine and carina improved combined target coverage, compared with tattoos, in 50% and 34% (spine) to 54% and 46% (carina) of the first and final fractions, respectively. Carina matching showed greater combined target coverage in 17% and 23% of fractions for the first and final fractions, respectively; with spine matching, this was only observed in 4% (first) and 6% (final) of fractions. Carina matching provided superior nodes coverage at the end of radiation compared with spine matching (P=.0006), without compromising primary tumor coverage. Conclusion: Frequent patient setup errors occur in locally advanced lung cancer patients. Spine and carina registrations improved combined target coverage throughout the treatment course, but carina matching provided superior combined target coverage.« less
MO-FG-CAMPUS-TeP2-04: Optimizing for a Specified Target Coverage Probability
DOE Office of Scientific and Technical Information (OSTI.GOV)
Fredriksson, A
2016-06-15
Purpose: The purpose of this work is to develop a method for inverse planning of radiation therapy margins. When using this method the user specifies a desired target coverage probability and the system optimizes to meet the demand without any explicit specification of margins to handle setup uncertainty. Methods: The method determines which voxels to include in an optimization function promoting target coverage in order to achieve a specified target coverage probability. Voxels are selected in a way that retains the correlation between them: The target is displaced according to the setup errors and the voxels to include are selectedmore » as the union of the displaced target regions under the x% best scenarios according to some quality measure. The quality measure could depend on the dose to the considered structure alone or could depend on the dose to multiple structures in order to take into account correlation between structures. Results: A target coverage function was applied to the CTV of a prostate case with prescription 78 Gy and compared to conventional planning using a DVH function on the PTV. Planning was performed to achieve 90% probability of CTV coverage. The plan optimized using the coverage probability function had P(D98 > 77.95 Gy) = 0.97 for the CTV. The PTV plan using a constraint on minimum DVH 78 Gy at 90% had P(D98 > 77.95) = 0.44 for the CTV. To match the coverage probability optimization, the DVH volume parameter had to be increased to 97% which resulted in 0.5 Gy higher average dose to the rectum. Conclusion: Optimizing a target coverage probability is an easily used method to find a margin that achieves the desired coverage probability. It can lead to reduced OAR doses at the same coverage probability compared to planning with margins and DVH functions.« less
Dosimetric comparison of photon and proton treatment techniques for chondrosarcoma of thoracic spine
DOE Office of Scientific and Technical Information (OSTI.GOV)
Yadav, Poonam, E-mail: yadav@humonc.wisc.edu; Department of Medical Physics, University of Wisconsin, Madison, WI; University of Wisconsin Riverview Cancer Center, Wisconsin Rapids, WI
2013-10-01
Chondrosarcomas are relatively radiotherapy resistant, and also delivering high radiation doses is not feasible owing to anatomic constraints. In this study, the feasibility of helical tomotherapy for treatment of chondrosarcoma of thoracic spine is explored and compared with other available photon and proton radiotherapy techniques in the clinical setting. A patient was treated for high-grade chondrosarcoma of the thoracic spine using tomotherapy. Retrospectively, the tomotherapy plan was compared with intensity-modulated radiation therapy, dynamic arc photon therapy, and proton therapy. Two primary comparisons were made: (1) comparison of normal tissue sparing with comparable target volume coverage (plan-1), and (2) comparison ofmore » target volume coverage with a constrained maximum dose to the cord center (plan-2). With constrained target volume coverage, proton plans were found to yield lower mean doses for all organs at risk (spinal cord, esophagus, heart, and both lungs). Tomotherapy planning resulted in the lowest mean dose to all organs at risk amongst photon-based methods. For cord dose constrained plans, the static-field intensity-modulated radiation therapy and dynamic arc plans resulted target underdosing in 20% and 12% of planning target volume2 volumes, respectively, whereas both proton and tomotherapy plans provided clinically acceptable target volume coverage with no portion of planning target volume2 receiving less than 90% of the prescribed dose. Tomotherapy plans are comparable to proton plans and produce superior results compared with other photon modalities. This feasibility study suggests that tomotherapy is an attractive alternative to proton radiotherapy for delivering high doses to lesions in the thoracic spine.« less
Murthy, Kk; Shukeili, Ka; Kumar, Ss; Davis, Ca; Chandran, Rr; Namrata, S
2010-01-01
To assess the potential advantage of intensity-modulated radiotherapy (IMRT) over 3D-conformal radiotherapy (3D-CRT) planning in postoperative adjuvant radiotherapy for patients with gastric carcinoma. In a retrospective study, for plan comparison, dose distribution was recalculated in 15 patients treated with 3D-CRT on the contoured structures of same CT images using an IMRT technique. 3D-conformal plans with three fields and four-fields were compared with seven-field dynamic IMRT plans. The different plans were compared by analyzing the dose coverage of planning target volume using TV(95), D(mean), uniformity index, conformity index and homogeneity index parameters. To assess critical organ sparing, D(mean), D(max), dose to one-third and two-third volumes of the OARs and percentage of volumes receiving more than their tolerance doses were compared. The average dose coverage values of PTV with 3F-CRT and 4F-CRT plans were comparable, where as IMRT plans achieved better target coverage(p<0.001) with higher conformity index value of 0.81±0.07 compared to both the 3D-CRT plans. The doses to the liver and bowel reduced significantly (p<0.001) with IMRT plans compared to other 3D-CRT plans. For all OARs the percentage of volumes receiving more than their tolerance doses were reduced with the IMRT plans. This study showed that a better target coverage and significant dose reduction to OARs could be achieved with the IMRT plans. The IMRT can be preferred with caution for organ motion. The authors are currently studying organ motion in the upper abdomen to use IMRT for patient treatment.
Feiring, Berit; Laake, Ida; Molden, Tor; Håberg, Siri E; Nøkleby, Hanne; Seterelv, Siri Schøyen; Magnus, Per; Trogstad, Lill
2016-04-12
Selective immunisation is an alternative to universal vaccination if children at increased risk of disease can be identified. Within the Norwegian Childhood Immunisation Programme, BCG vaccine against tuberculosis and vaccine against hepatitis B virus (HBV) are offered only to children with parents from countries with high burden of the respective disease. We wanted to study whether this selective immunisation policy reaches the targeted groups. The study population was identified through the Norwegian Central Population Registry and consisted of all children born in Norway 2007-2010 and residing in Norway until their second birthday, in total 240,484 children. Information on vaccinations from the Norwegian Immunisation Registry, and on parental country of birth from Statistics Norway, was linked to the population registry by personal identifiers. The coverage of BCG and HBV vaccine was compared with the coverage of vaccines in the universal programme. Among the study population, 16.1% and 15.9% belonged to the target groups for BCG and HBV vaccine, respectively. Among children in the BCG target group the BCG vaccine coverage was lower than the coverage of pertussis and measles vaccine (83.6% vs. 98.6% and 92.3%, respectively). Likewise, the HBV vaccine coverage was lower than the coverage of pertussis and measles vaccine in the HBV target group (90.0% vs. 98.6% and 92.3%, respectively). The coverage of the targeted vaccines was highest among children with parents from South Asia and Sub-Saharan Africa. The coverage of vaccines in the universal programme was similar in targeted and non-targeted groups. Children targeted by selective vaccination had lower coverage of the target vaccines than of vaccines in the universal programme, indicating that selective vaccination is challenging. Improved routines for identifying eligible children and delivering the target vaccines are needed. Universal vaccination of all children with these vaccines could be considered. Copyright © 2016 Elsevier Ltd. All rights reserved.
Target coverage in image-guided stereotactic body radiotherapy of liver tumors.
Wunderink, Wouter; Méndez Romero, Alejandra; Vásquez Osorio, Eliana M; de Boer, Hans C J; Brandwijk, René P; Levendag, Peter C; Heijmen, Ben J M
2007-05-01
To determine the effect of image-guided procedures (with computed tomography [CT] and electronic portal images before each treatment fraction) on target coverage in stereotactic body radiotherapy for liver patients using a stereotactic body frame (SBF) and abdominal compression. CT guidance was used to correct for day-to-day variations in the tumor's mean position in the SBF. By retrospectively evaluating 57 treatment sessions, tumor coverage, as obtained with the clinically applied CT-guided protocol, was compared with that of alternative procedures. The internal target volume-plus (ITV(+)) was introduced to explicitly include uncertainties in tumor delineations resulting from CT-imaging artifacts caused by residual respiratory motion. Tumor coverage was defined as the volume overlap of the ITV(+), derived from a tumor delineated in a treatment CT scan, and the planning target volume. Patient stability in the SBF, after acquisition of the treatment CT scan, was evaluated by measuring the displacement of the bony anatomy in the electronic portal images relative to CT. Application of our clinical protocol (with setup corrections following from manual measurements of the distances between the contours of the planning target volume and the daily clinical target volume in three orthogonal planes, multiple two-dimensional) increased the frequency of nearly full (> or = 99%) ITV(+) coverage to 77% compared with 63% without setup correction. An automated three-dimensional method further improved the frequency to 96%. Patient displacements in the SBF were generally small (< or = 2 mm, 1 standard deviation), but large craniocaudal displacements (maximal 7.2 mm) were occasionally observed. Daily, CT-assisted patient setup may substantially improve tumor coverage, especially with the automated three-dimensional procedure. In the present treatment design, patient stability in the SBF should be verified with portal imaging.
Measuring populations to improve vaccination coverage
NASA Astrophysics Data System (ADS)
Bharti, Nita; Djibo, Ali; Tatem, Andrew J.; Grenfell, Bryan T.; Ferrari, Matthew J.
2016-10-01
In low-income settings, vaccination campaigns supplement routine immunization but often fail to achieve coverage goals due to uncertainty about target population size and distribution. Accurate, updated estimates of target populations are rare but critical; short-term fluctuations can greatly impact population size and susceptibility. We use satellite imagery to quantify population fluctuations and the coverage achieved by a measles outbreak response vaccination campaign in urban Niger and compare campaign estimates to measurements from a post-campaign survey. Vaccine coverage was overestimated because the campaign underestimated resident numbers and seasonal migration further increased the target population. We combine satellite-derived measurements of fluctuations in population distribution with high-resolution measles case reports to develop a dynamic model that illustrates the potential improvement in vaccination campaign coverage if planners account for predictable population fluctuations. Satellite imagery can improve retrospective estimates of vaccination campaign impact and future campaign planning by synchronizing interventions with predictable population fluxes.
Measuring populations to improve vaccination coverage
Bharti, Nita; Djibo, Ali; Tatem, Andrew J.; Grenfell, Bryan T.; Ferrari, Matthew J.
2016-01-01
In low-income settings, vaccination campaigns supplement routine immunization but often fail to achieve coverage goals due to uncertainty about target population size and distribution. Accurate, updated estimates of target populations are rare but critical; short-term fluctuations can greatly impact population size and susceptibility. We use satellite imagery to quantify population fluctuations and the coverage achieved by a measles outbreak response vaccination campaign in urban Niger and compare campaign estimates to measurements from a post-campaign survey. Vaccine coverage was overestimated because the campaign underestimated resident numbers and seasonal migration further increased the target population. We combine satellite-derived measurements of fluctuations in population distribution with high-resolution measles case reports to develop a dynamic model that illustrates the potential improvement in vaccination campaign coverage if planners account for predictable population fluctuations. Satellite imagery can improve retrospective estimates of vaccination campaign impact and future campaign planning by synchronizing interventions with predictable population fluxes. PMID:27703191
A Two-Phase Coverage-Enhancing Algorithm for Hybrid Wireless Sensor Networks.
Zhang, Qingguo; Fok, Mable P
2017-01-09
Providing field coverage is a key task in many sensor network applications. In certain scenarios, the sensor field may have coverage holes due to random initial deployment of sensors; thus, the desired level of coverage cannot be achieved. A hybrid wireless sensor network is a cost-effective solution to this problem, which is achieved by repositioning a portion of the mobile sensors in the network to meet the network coverage requirement. This paper investigates how to redeploy mobile sensor nodes to improve network coverage in hybrid wireless sensor networks. We propose a two-phase coverage-enhancing algorithm for hybrid wireless sensor networks. In phase one, we use a differential evolution algorithm to compute the candidate's target positions in the mobile sensor nodes that could potentially improve coverage. In the second phase, we use an optimization scheme on the candidate's target positions calculated from phase one to reduce the accumulated potential moving distance of mobile sensors, such that the exact mobile sensor nodes that need to be moved as well as their final target positions can be determined. Experimental results show that the proposed algorithm provided significant improvement in terms of area coverage rate, average moving distance, area coverage-distance rate and the number of moved mobile sensors, when compare with other approaches.
Goswami, Jyotirup; Patra, Niladri B.; Sarkar, Biplab; Basu, Ayan; Pal, Santanu
2013-01-01
Background and Purpose: Conventional portals, based on bony anatomy, for external beam radiotherapy for cervical cancer have been repeatedly demonstrated as inadequate. Conversely, with image-based conformal radiotherapy, better target coverage may be offset by the greater toxicities and poorer compliance associated with treating larger volumes. This study was meant to dosimetrically compare conformal and conventional radiotherapy. Materials and Methods: Five patients of carcinoma cervix underwent planning CT scan with IV contrast and targets, and organs at risk (OAR) were contoured. Two sets of plans-conventional and conformal were generated for each patient. Field sizes were recorded, and dose volume histograms of both sets of plans were generated and compared on the basis of target coverage and OAR sparing. Results: Target coverage was significantly improved with conformal plans though field sizes required were significantly larger. On the other hand, dose homogeneity was not significantly improved. Doses to the OARs (rectum, urinary bladder, and small bowel) were not significantly different across the 2 arms. Conclusion: Three-dimensional conformal radiotherapy gives significantly better target coverage, which may translate into better local control and survival. On the other hand, it also requires significantly larger field sizes though doses to the OARs are not significantly increased. PMID:24455584
A Two-Phase Coverage-Enhancing Algorithm for Hybrid Wireless Sensor Networks
Zhang, Qingguo; Fok, Mable P.
2017-01-01
Providing field coverage is a key task in many sensor network applications. In certain scenarios, the sensor field may have coverage holes due to random initial deployment of sensors; thus, the desired level of coverage cannot be achieved. A hybrid wireless sensor network is a cost-effective solution to this problem, which is achieved by repositioning a portion of the mobile sensors in the network to meet the network coverage requirement. This paper investigates how to redeploy mobile sensor nodes to improve network coverage in hybrid wireless sensor networks. We propose a two-phase coverage-enhancing algorithm for hybrid wireless sensor networks. In phase one, we use a differential evolution algorithm to compute the candidate’s target positions in the mobile sensor nodes that could potentially improve coverage. In the second phase, we use an optimization scheme on the candidate’s target positions calculated from phase one to reduce the accumulated potential moving distance of mobile sensors, such that the exact mobile sensor nodes that need to be moved as well as their final target positions can be determined. Experimental results show that the proposed algorithm provided significant improvement in terms of area coverage rate, average moving distance, area coverage–distance rate and the number of moved mobile sensors, when compare with other approaches. PMID:28075365
Neal, Sarah; Channon, Andrew Amos; Carter, Sarah; Falkingham, Jane
2015-06-16
The drive toward universal health coverage (UHC) is central to the post 2015 agenda, and is incorporated as a target in the new Sustainable Development Goals. However, it is recognised that an equity dimension needs to be included when progress to this goal is monitored. WHO have developed a monitoring framework which proposes a target of 80% coverage for all populations regardless of income and place of residence by 2030, and this paper examines the feasibility of this target in relation to antenatal care and skilled care at delivery. We analyse the coverage gap between the poorest and richest groups within the population for antenatal care and presence of a skilled attendant at birth for countries grouped by overall coverage of each maternal health service. Average annual rates of improvement needed for each grouping (disaggregated by wealth quintile and urban/rural residence) to reach the goal are also calculated, alongside rates of progress over the past decades for comparative purposes. Marked inequities are seen in all groups except in countries where overall coverage is high. As the monitoring framework has an absolute target countries with currently very low coverage are required to make rapid and sustained progress, in particular for the poorest and those living in rural areas. The rate of past progress will need to be accelerated markedly in most countries if the target is to be achieved, although several countries have demonstrated the rate of progress required is feasible both for the population as a whole and for the poorest. For countries with currently low coverage the target of 80% essential coverage for all populations will be challenging. Lessons should be drawn from countries who have achieved rapid and equitable progress in the past.
Impact of organ shape variations on margin concepts for cervix cancer ART.
Seppenwoolde, Yvette; Stock, Markus; Buschmann, Martin; Georg, Dietmar; Bauer-Novotny, Kwei-Yuang; Pötter, Richard; Georg, Petra
2016-09-01
Target and organ movement motivate adaptive radiotherapy for cervix cancer patients. We investigated the dosimetric impact of margin concepts with different levels of complexity on both organ at risk (OAR) sparing and PTV coverage. Weekly CT and daily CBCT scans were delineated for 10 patients. The dosimetric impact of organ shape variations were evaluated for four (isotropic) margin concepts: two static PTVs (PTV 6mm and PTV 15mm ), a PTV based on ITV of the planning CT and CBCTs of the first treatment week (PTV ART ITV ) and an adaptive PTV based on a library approach (PTV ART Library ). Using static concepts, OAR doses increased with large margins, while smaller margins compromised target coverage. ART PTVs resulted in comparable target coverage and better sparing of bladder (V40Gy: 15% and 7% less), rectum (V40Gy: 18 and 6cc less) and bowel (V40Gy: 106 and 15cc less) compared to PTV 15mm . Target coverage evaluation showed that for elective fields a static 5mm margin sufficed. PTV ART Library achieved the best dosimetric results. However when weighing clinical benefit against workload, ITV margins based on repetitive movement evaluation during the first week also provide improvements over static margin concepts. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Pokhrel, D; Sood, S; Badkul, R
2015-06-15
Purpose: To investigate the feasibility of using RapidArc (RA) treatment planning to reduce irradiation volume of normal lung and other organs at risk (OARs) in the treatment of inoperable non-small-cell lung cancer (NSCLC) patients. Methods: A retrospective treatment planning and delivery study was performed to compare target coverage and the volumes of the normal lung, spinal cord, heart and esophagus on 4D-CT scan above their dose tolerances delivered by RA vs. IMRT for ten inoperable NSCLC patients (Stage I-IIIB). RA plans consisted of either one-full or two-partial co-planar arcs used to treat 95% of the planning target volume (PTV) withmore » 6MV beam to a prescription of 66Gy in 33 fractions. IMRT plans were generated using 5–7 co-planar fields with 6MV beam. PTV coverage, dose-volume histograms, homogeneity/conformity indices (CI), total number of monitor units(MUs), beam-on time and delivery accuracy were compared between the two treatment plans. Results: Similar target coverage was obtained between the two techniques. RA (CI=1.02) provided more conformal plans without loss of homogeneity compared to IMRT plans (CI=1.12). Compared to IMRT, RA achieved a significant median dose reduction in V10 (3%), V20 (8%), and mean lung dose (3%) on average, respectively. On average, V5 was comparable between the two treatment plans. RA reduced mean esophagus (6%), mean heart (18%), and maximum spinal cord dose (7%), on average, respectively. Total number of MUs and beam-on time were each reduced almost by a factor of 2 when compared to IMRT-patient comfort, reduced intra-fraction-motion and leakage dose. The average IMRT and RA QA pass rate was about 98% for both types of plans for 3%/3mm criterion. Conclusion: Compared to IMRT plans, RA provided not only comparable target coverage, but also improved conformity, treatment time, and significant reduction in irradiation of OARs. This may potentially allow for target dose escalation without increase in normal tissue toxicity.« less
Oldenburg, Catherine E; Amza, Abdou; Kadri, Boubacar; Nassirou, Beido; Cotter, Sun Y; Stoller, Nicole E; West, Sheila K; Bailey, Robin L; Porco, Travis C; Gaynor, Bruce D; Keenan, Jeremy D; Lietman, Thomas M
2018-02-01
Repeated oral azithromycin distribution targeted only to children has proven effective in reducing the ocular Chlamydia that causes trachoma. Here, we assess whether an enhanced coverage target of at least 90% of children is superior to the World Health Organization recommendation of at least 80%. Twenty-four trachoma-endemic communities in Matamèye, Niger, were randomized to a single day of azithromycin distribution aiming for at least 80% coverage or up to 4 days of treatment and > 90% coverage of children under age 12. All distributions were biannual. Children < 5 years of age and adults > 15 years were monitored for ocular Chlamydia infection by polymerase chain reaction every 6 months for 36 months in children and at baseline and 36 months in adults. Ocular Chlamydia prevalence in children decreased from 24.9% (95% confidence interval [CI] 15.9-33.8%) to 4.4% (95% CI 0.6-8.2%, P < 0.001) at 36 months in the standard coverage arm and from 15.6% (95% CI 10.0-21.2%) to 3.3% (95% CI 1.0-5.5%; P < 0.001) in the enhanced coverage arm. Enhanced coverage reduced ocular Chlamydia prevalence in children more quickly over time compared with standard ( P = 0.04). There was no difference between arms at 36 months in children (2.4% lower with enhanced coverage, 95% CI 7.7-12.5%; P = 0.60). No infection was detected in adults at 36 months. Increasing antibiotic coverage among children from 80% to 90% may yield only short term improvements for trachoma control programs. Targeting treatment to children alone may be sufficient for trachoma control in this setting.
A method for deriving a 4D-interpolated balanced planning target for mobile tumor radiotherapy.
Roland, Teboh; Hales, Russell; McNutt, Todd; Wong, John; Simari, Patricio; Tryggestad, Erik
2012-01-01
Tumor control and normal tissue toxicity are strongly correlated to the tumor and normal tissue volumes receiving high prescribed dose levels in the course of radiotherapy. Planning target definition is, therefore, crucial to ensure favorable clinical outcomes. This is especially important for stereotactic body radiation therapy of lung cancers, characterized by high fractional doses and steep dose gradients. The shift in recent years from population-based to patient-specific treatment margins, as facilitated by the emergence of 4D medical imaging capabilities, is a major improvement. The commonly used motion-encompassing, or internal-target volume (ITV), target definition approach provides a high likelihood of coverage for the mobile tumor but inevitably exposes healthy tissue to high prescribed dose levels. The goal of this work was to generate an interpolated balanced planning target that takes into account both tumor coverage and normal tissue sparing from high prescribed dose levels, thereby improving on the ITV approach. For each 4DCT dataset, 4D deformable image registration was used to derive two bounding targets, namely, a 4D-intersection and a 4D-composite target which minimized normal tissue exposure to high prescribed dose levels and maximized tumor coverage, respectively. Through definition of an "effective overlap volume histogram" the authors derived an "interpolated balanced planning target" intended to balance normal tissue sparing from prescribed doses with tumor coverage. To demonstrate the dosimetric efficacy of the interpolated balanced planning target, the authors performed 4D treatment planning based on deformable image registration of 4D-CT data for five previously treated lung cancer patients. Two 4D plans were generated per patient, one based on the interpolated balanced planning target and the other based on the conventional ITV target. Plans were compared for tumor coverage and the degree of normal tissue sparing resulting from the new approach was quantified. Analysis of the 4D dose distributions from all five patients showed that while achieving tumor coverage comparable to the ITV approach, the new planning target definition resulted in reductions of lung V(10), V(20), and V(30) of 6.3% ± 1.7%, 10.6% ± 3.9%, and 12.9% ± 5.5%, respectively, as well as reductions in mean lung dose, mean dose to the GTV-ring and mean heart dose of 8.8% ± 2.5%, 7.2% ± 2.5%, and 10.6% ± 3.6%, respectively. The authors have developed a simple and systematic approach to generate a 4D-interpolated balanced planning target volume that implicitly incorporates the dynamics of respiratory-organ motion without requiring 4D-dose computation or optimization. Preliminary results based on 4D-CT data of five previously treated lung patients showed that this new planning target approach may improve normal tissue sparing without sacrificing tumor coverage.
Paluska, Petr; Hanus, Josef; Sefrova, Jana; Rouskova, Lucie; Grepl, Jakub; Jansa, Jan; Kasaova, Linda; Hodek, Miroslav; Zouhar, Milan; Vosmik, Milan; Petera, Jiri
2012-01-01
To assess target volume coverage during prostate image-guided radiotherapy based on bony anatomy alignment and to assess possibility of safety margin reduction. Implementation of IGRT should influence safety margins. Utilization of cone-beam CT provides current 3D anatomic information directly in irradiation position. Such information enables reconstruction of the actual dose distribution. Seventeen prostate patients were treated with daily bony anatomy image-guidance. Cone-beam CT (CBCT) scans were acquired once a week immediately after bony anatomy alignment. After the prostate, seminal vesicles, rectum and bladder were contoured, the delivered dose distribution was reconstructed. Target dose coverage was evaluated by the proportion of the CTV encompassed by the 95% isodose. Original plans employed a 1 cm safety margin. Alternative plans assuming a smaller 7 mm margin between CTV and PTV were evaluated in the same way. Rectal and bladder volumes were compared with the initial ones. Rectal and bladder volumes irradiated with doses higher than 75 Gy, 70 Gy, 60 Gy, 50 Gy and 40 Gy were analyzed. In 12% of reconstructed plans the prostate coverage was not sufficient. The prostate underdosage was observed in 5 patients. Coverage of seminal vesicles was not satisfactory in 3% of plans. Most of the target underdosage corresponded to excessive rectal or bladder filling. Evaluation of alternative plans assuming a smaller 7 mm margin revealed 22% and 11% of plans where prostate and seminal vesicles coverage, respectively, was compromised. These were distributed over 8 and 7 patients, respectively. Sufficient dose coverage of target volumes was not achieved for all patients. Reducing of safety margin is not acceptable. Initial rectal and bladder volumes cannot be considered representative for subsequent treatment.
Latsuzbaia, Ardashel; Arbyn, Marc; Weyers, Steven; Mossong, Joël
2018-04-25
In Luxembourg, a national Human Papillomavirus (HPV) vaccination programme was introduced in 2008, targeting 12-17 year old girls offering a choice of bivalent or quadrivalent vaccine free of charge. In 2015, the programme was changed offering the bivalent vaccine only to 11-13 year old girls. The aim of this study was to evaluate the HPV vaccination coverage, to assess the impact of age target changes and compare vaccination coverage to other European countries. Anonymous HPV vaccination records consisting of individual vaccine doses obtained free of charge in pharmacies between 2008 and 2016 were extracted from the Luxembourgish Social Security database. Additional aggregate tables by nationality and municipality were analysed. Of the target cohort of 39,610 girls born between 1991 and 2003 residing in Luxembourg, 24,550 (62.0%) subjects obtained at least one dose, 22,082 (55.7%) obtained at least two doses, and 17,197 (43.4%) obtained three doses of HPV vaccine. The mean age at first dose was 13.7 years during 2008-14 and 12.7 years in 2016 after the age target change. Coverage varied significantly by nationality (p < 0.0001): Portuguese (80%), former Yugoslavs (74%), Luxembourgish (54%), Belgian (52%), German (47%), French (39%) and other nationalities (51%). Coverage varied also by geographical region, with lower rates (<50%) noted in some Northern and Central areas of Luxembourg (range: 38% to 78%). Overall HPV vaccination coverage in Luxembourg is moderate and varied by nationality and region. The policy changes in 2015 did not have a substantial impact except lowering age at initiating vaccination. Options to improve coverage deserve further investigation. Copyright © 2018 The Author(s). Published by Elsevier Ltd.. All rights reserved.
Ranger, A; Dunlop, A; Hutchinson, K; Convery, H; Maclennan, M K; Chantler, H; Twyman, N; Rose, C; McQuaid, D; Amos, R A; Griffin, C; deSouza, N M; Donovan, E; Harris, E; Coles, C E; Kirby, A
2018-06-01
Radiotherapy target volumes in early breast cancer treatment increasingly include the internal mammary chain (IMC). In order to maximise survival benefits of IMC radiotherapy, doses to the heart and lung should be minimised. This dosimetry study compared the ability of three-dimensional conformal radiotherapy, arc therapy and proton beam therapy (PBT) techniques with and without breath-hold to achieve target volume constraints while minimising dose to organs at risk (OARs). In 14 patients' datasets, seven IMC radiotherapy techniques were compared: wide tangent (WT) three-dimensional conformal radiotherapy, volumetric-modulated arc therapy (VMAT) and PBT, each in voluntary deep inspiratory breath-hold (vDIBH) and free breathing (FB), and tomotherapy in FB only. Target volume coverage and OAR doses were measured for each technique. These were compared using a one-way ANOVA with all pairwise comparisons tested using Bonferroni's multiple comparisons test, with adjusted P-values ≤ 0.05 indicating statistical significance. One hundred per cent of WT(vDIBH), 43% of WT(FB), 100% of VMAT(vDIBH), 86% of VMAT(FB), 100% of tomotherapy FB and 100% of PBT plans in vDIBH and FB passed all mandatory constraints. However, coverage of the IMC with 90% of the prescribed dose was significantly better than all other techniques using VMAT(vDIBH), PBT(vDIBH) and PBT(FB) (mean IMC coverage ± 1 standard deviation = 96.0% ± 4.3, 99.8% ± 0.3 and 99.0% ± 0.2, respectively). The mean heart dose was significantly reduced in vDIBH compared with FB for both the WT (P < 0.0001) and VMAT (P < 0.0001) techniques. There was no advantage in target volume coverage or OAR doses for PBT(vDIBH) compared with PBT(FB). Simple WT radiotherapy delivered in vDIBH achieves satisfactory coverage of the IMC while meeting heart and lung dose constraints. However, where higher isodose coverage is required, VMAT(vDIBH) is the optimal photon technique. The lowest OAR doses are achieved by PBT, in which the use of vDIBH does not improve dose statistics. Crown Copyright © 2018. Published by Elsevier Ltd. All rights reserved.
Delaunay Triangulation as a New Coverage Measurement Method in Wireless Sensor Network
Chizari, Hassan; Hosseini, Majid; Poston, Timothy; Razak, Shukor Abd; Abdullah, Abdul Hanan
2011-01-01
Sensing and communication coverage are among the most important trade-offs in Wireless Sensor Network (WSN) design. A minimum bound of sensing coverage is vital in scheduling, target tracking and redeployment phases, as well as providing communication coverage. Some methods measure the coverage as a percentage value, but detailed information has been missing. Two scenarios with equal coverage percentage may not have the same Quality of Coverage (QoC). In this paper, we propose a new coverage measurement method using Delaunay Triangulation (DT). This can provide the value for all coverage measurement tools. Moreover, it categorizes sensors as ‘fat’, ‘healthy’ or ‘thin’ to show the dense, optimal and scattered areas. It can also yield the largest empty area of sensors in the field. Simulation results show that the proposed DT method can achieve accurate coverage information, and provides many tools to compare QoC between different scenarios. PMID:22163792
Seeking consensus on universal health coverage indicators in the sustainable development goals.
Reddock, Jennifer
2017-01-01
There is optimism that the inclusion of universal health coverage in the Sustainable Development Goals advances its prominence in global and national health policy. However, formulating indicators for Target 3.8 through the Inter-Agency Expert Group on Sustainable Development Indicators has been challenging. Achieving consensus on the conceptual and methodological aspects of universal health coverage is likely to take some time in multi-stakeholder fora compared with national efforts to select indicators.
The influence of performance-based payment on childhood immunisation coverage.
Merilind, Eero; Salupere, Rauno; Västra, Katrin; Kalda, Ruth
2015-06-01
Pay-for-performance, also called the quality system (QS) in Estonia, was implemented in 2006 and one indicator for achievement is the childhood immunisation coverage rate. The WHO vaccination coverage in Europe for diphtheria, tetanus and pertussis, and measles in children aged around one year old should meet or exceed 90 per cent. The study was conducted using a database from the Estonian Health Insurance Fund. The study compared childhood immunisation coverage rates of all Estonian family physicians in two groups, joined and not joined to the quality system during the observation period 2006-2012. Immunisation coverage was calculated as the percentage of persons in the target age group who received a vaccine dose by a given age. The target level of immunisations in Estonia is set at 90 per cent and higher. Immunisation coverage rates of family doctors (FD) in Estonia showed significant differences between two groups of doctors: joined to the quality system and not joined. Doctors joined to the quality system met the 90 per cent vaccination criterion more frequently compared to doctors not joined to the quality system. Doctors not joined to the quality system were below the 90 per cent vaccination criterion in all vaccinations listed in the Estonian State Immunisation Schedule. Pay-for-performance as a financial incentive encourages higher levels of childhood immunisations. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.
Levi, Jacob; Pozniak, Anton; Heath, Katherine; Hill, Andrew
2018-04-01
In 2014, UNAIDS and partners set the 90-90-90 targets for the HIV treatment cascade. Multiple social, political and structural factors might influence progress towards these targets. We assessed how close countries and regions are to reaching these targets, and compared cascade outcomes with HIV prevalence, gross domestic product (GDP)/capita, conflict and corruption. Country-level HIV cascade data on diagnosis, ART coverage and viral suppression, from 2010 to 2016 were extracted from national reports, published papers and the www.AIDSinfoOnline database, and analysed. Weighted least-squares regression was used to assess predictors of cascade achievement: region, HIV prevalence, GDP/capita, the 2016 Corruption Perceptions Index (CPI), which is an international ranking system, and the 2016 Global Peace Index (GPI), which ranks all countries based on three main categories: societal safety, militarisation and conflict. Data were available for diagnosis for 84 countries, ART coverage for 137 countries, and viral suppression for 94 countries. Regions with the lowest ART coverage were South-east Asia and Pacific (36%), Eastern Europe and Central Asia (17%), and Middle East and North Africa (13%). Lower HIV prevalence was associated with poorer cascade results. Countries with higher GDP/capita achieved higher ART coverage ( P <0.001). Furthermore, countries with lower levels of peace and higher corruption had lower ART coverage ( P <0.001). Countries with a GPI >2.5 all had ART coverage of <40%. Only one country has reached the UNAIDS 90-90-90 targets. International comparison remains difficult due to heterogeneous data reporting. Difficulty meeting UNAIDS targets is associated with lower GDP/capita, lower HIV prevalence, higher corruption and conflict levels.
On Connected Target k-Coverage in Heterogeneous Wireless Sensor Networks.
Yu, Jiguo; Chen, Ying; Ma, Liran; Huang, Baogui; Cheng, Xiuzhen
2016-01-15
Coverage and connectivity are two important performance evaluation indices for wireless sensor networks (WSNs). In this paper, we focus on the connected target k-coverage (CTC k) problem in heterogeneous wireless sensor networks (HWSNs). A centralized connected target k-coverage algorithm (CCTC k) and a distributed connected target k-coverage algorithm (DCTC k) are proposed so as to generate connected cover sets for energy-efficient connectivity and coverage maintenance. To be specific, our proposed algorithms aim at achieving minimum connected target k-coverage, where each target in the monitored region is covered by at least k active sensor nodes. In addition, these two algorithms strive to minimize the total number of active sensor nodes and guarantee that each sensor node is connected to a sink, such that the sensed data can be forwarded to the sink. Our theoretical analysis and simulation results show that our proposed algorithms outperform a state-of-art connected k-coverage protocol for HWSNs.
Progress toward measles preelimination--African Region, 2011-2012.
Masresha, Balcha G; Kaiser, Reinhard; Eshetu, Messeret; Katsande, Reggis; Luce, Richard; Fall, Amadou; Dosseh, Annick R G A; Naouri, Boubker; Byabamazima, Charles R; Perry, Robert; Dabbagh, Alya J; Strebel, Peter; Kretsinger, Katrina; Goodson, James L; Nshimirimana, Deo
2014-04-04
In 2008, the 46 member states of the World Health Organization (WHO) African Region (AFR) adopted a measles preelimination goal to reach by the end of 2012 with the following targets: 1) >98% reduction in estimated regional measles mortality compared with 2000, 2) annual measles incidence of fewer than five reported cases per million population nationally, 3) >90% national first dose of measles-containing vaccine (MCV1) coverage and >80% MCV1 coverage in all districts, and 4) >95% MCV coverage in all districts by supplementary immunization activities (SIAs). Surveillance performance objectives were to report two or more cases of nonmeasles febrile rash illness per 100,000 population, one or more suspected measles cases investigated with blood specimens in ≥80% of districts, and 100% completeness of surveillance reporting from all districts. This report updates previous reports and describes progress toward the measles preelimination goal during 2011-2012. In 2012, 13 (28%) member states had >90% MCV1 coverage, and three (7%) reported >90% MCV1 coverage nationally and >80% coverage in all districts. During 2011-2012, four (15%) of 27 SIAs with available information met the target of >95% coverage in all districts. In 2012, 16 of 43 (37%) member states met the incidence target of fewer than five cases per million, and 19 of 43 (44%) met both surveillance performance targets. In 2011, the WHO Regional Committee for AFR established a goal to achieve measles elimination by 2020. To achieve this goal, intensified efforts to identify and close population immunity gaps and improve surveillance quality are needed, as well as committed leadership and ownership of the measles elimination activities and mobilization of adequate resources to complement funding from global partners.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Burnum-Johnson, Kristin E.; Nie, Song; Casey, Cameron P.
Current proteomics approaches are comprised of both broad discovery measurements as well as more quantitative targeted measurements. These two different measurement types are used to initially identify potentially important proteins (e.g., candidate biomarkers) and then enable improved quantification for a limited number of selected proteins. However, both approaches suffer from limitations, particularly the lower sensitivity, accuracy, and quantitation precision for discovery approaches compared to targeted approaches, and the limited proteome coverage provided by targeted approaches. Herein, we describe a new proteomics approach that allows both discovery and targeted monitoring (DTM) in a single analysis using liquid chromatography, ion mobility spectrometrymore » and mass spectrometry (LC-IMS-MS). In DTM, heavy labeled peptides for target ions are spiked into tryptic digests and both the labeled and unlabeled peptides are broadly detected using LC-IMS-MS instrumentation, allowing the benefits of discovery and targeted approaches. To understand the possible improvement of the DTM approach, it was compared to LC-MS broad measurements using an accurate mass and time tag database and selected reaction monitoring (SRM) targeted measurements. The DTM results yielded greater peptide/protein coverage and a significant improvement in the detection of lower abundance species compared to LC-MS discovery measurements. DTM was also observed to have similar detection limits as SRM for the targeted measurements indicating its potential for combining the discovery and targeted approaches.« less
Allnutt, Thomas F.; McClanahan, Timothy R.; Andréfouët, Serge; Baker, Merrill; Lagabrielle, Erwann; McClennen, Caleb; Rakotomanjaka, Andry J. M.; Tianarisoa, Tantely F.; Watson, Reg; Kremen, Claire
2012-01-01
The Government of Madagascar plans to increase marine protected area coverage by over one million hectares. To assist this process, we compare four methods for marine spatial planning of Madagascar's west coast. Input data for each method was drawn from the same variables: fishing pressure, exposure to climate change, and biodiversity (habitats, species distributions, biological richness, and biodiversity value). The first method compares visual color classifications of primary variables, the second uses binary combinations of these variables to produce a categorical classification of management actions, the third is a target-based optimization using Marxan, and the fourth is conservation ranking with Zonation. We present results from each method, and compare the latter three approaches for spatial coverage, biodiversity representation, fishing cost and persistence probability. All results included large areas in the north, central, and southern parts of western Madagascar. Achieving 30% representation targets with Marxan required twice the fish catch loss than the categorical method. The categorical classification and Zonation do not consider targets for conservation features. However, when we reduced Marxan targets to 16.3%, matching the representation level of the “strict protection” class of the categorical result, the methods show similar catch losses. The management category portfolio has complete coverage, and presents several management recommendations including strict protection. Zonation produces rapid conservation rankings across large, diverse datasets. Marxan is useful for identifying strict protected areas that meet representation targets, and minimize exposure probabilities for conservation features at low economic cost. We show that methods based on Zonation and a simple combination of variables can produce results comparable to Marxan for species representation and catch losses, demonstrating the value of comparing alternative approaches during initial stages of the planning process. Choosing an appropriate approach ultimately depends on scientific and political factors including representation targets, likelihood of adoption, and persistence goals. PMID:22359534
Allnutt, Thomas F; McClanahan, Timothy R; Andréfouët, Serge; Baker, Merrill; Lagabrielle, Erwann; McClennen, Caleb; Rakotomanjaka, Andry J M; Tianarisoa, Tantely F; Watson, Reg; Kremen, Claire
2012-01-01
The Government of Madagascar plans to increase marine protected area coverage by over one million hectares. To assist this process, we compare four methods for marine spatial planning of Madagascar's west coast. Input data for each method was drawn from the same variables: fishing pressure, exposure to climate change, and biodiversity (habitats, species distributions, biological richness, and biodiversity value). The first method compares visual color classifications of primary variables, the second uses binary combinations of these variables to produce a categorical classification of management actions, the third is a target-based optimization using Marxan, and the fourth is conservation ranking with Zonation. We present results from each method, and compare the latter three approaches for spatial coverage, biodiversity representation, fishing cost and persistence probability. All results included large areas in the north, central, and southern parts of western Madagascar. Achieving 30% representation targets with Marxan required twice the fish catch loss than the categorical method. The categorical classification and Zonation do not consider targets for conservation features. However, when we reduced Marxan targets to 16.3%, matching the representation level of the "strict protection" class of the categorical result, the methods show similar catch losses. The management category portfolio has complete coverage, and presents several management recommendations including strict protection. Zonation produces rapid conservation rankings across large, diverse datasets. Marxan is useful for identifying strict protected areas that meet representation targets, and minimize exposure probabilities for conservation features at low economic cost. We show that methods based on Zonation and a simple combination of variables can produce results comparable to Marxan for species representation and catch losses, demonstrating the value of comparing alternative approaches during initial stages of the planning process. Choosing an appropriate approach ultimately depends on scientific and political factors including representation targets, likelihood of adoption, and persistence goals.
The role of helical tomotherapy in the treatment of bone plasmacytoma.
Chargari, Cyrus; Hijal, Tarek; Bouscary, Didier; Caussa, Lucas; Dendale, Remi; Zefkili, Sofia; Fourquet, Alain; Kirova, Youlia M
2012-01-01
We evaluated the early clinical outcome of patients with solitary bone plasmacytoma (SP) or a solitary lesion of multiple myeloma (MM) treated with helical tomotherapy (HT) compared with 3D conformal radiotherapy (3D-CRT), in terms of target coverage and exposure of critical organs. Ten patients with SP and 3 patients with a solitary lesion of MM underwent radiation therapy (RT) delivered by HT, to a dose of 40 Gy in 20 fractions. Treatment planning was then performed with 3D-CRT and the dosimetric parameters of both techniques were compared. Patients were also assessed for response to treatment and acute toxicities. With a median follow-up of 13 months, 78% of patients with pain before RT had resolution of their symptoms. Coverage of target lesion was adequate with both techniques in 12 of 13 patients. Target coverage was significantly lower for HT (V(95%) = 98.55% vs. 97.15%; p = 0.04, for 3D-CRT and HT, respectively). Target overdoses were also lower with HT (V(105%) = 2.01% vs. 0.19%; p= 0.16), although nonsignificant. Finally, there were no significant differences in organs-at-risk irradiation between both techniques. The early treatment tolerance was excellent, with no toxicity higher than grade I. RT of SP and MM with a solitary lesion can be safely delivered with HT, with no major acute side effects and good symptomatic control. Finally, HT provides a dosimetry similar to that of 3D-CRT in terms of organs-at-risk sparing and target volume coverage. Copyright © 2012 American Association of Medical Dosimetrists. Published by Elsevier Inc. All rights reserved.
Cordova, J. Scott; Kandula, Shravan; Gurbani, Saumya; Zhong, Jim; Tejani, Mital; Kayode, Oluwatosin; Patel, Kirtesh; Prabhu, Roshan; Schreibmann, Eduard; Crocker, Ian; Holder, Chad A.; Shim, Hyunsuk; Shu, Hui-Kuo
2017-01-01
Due to glioblastoma’s infiltrative nature, an optimal radiation therapy (RT) plan requires targeting infiltration not identified by anatomical magnetic resonance imaging (MRI). Here, high-resolution, whole-brain spectroscopic MRI (sMRI) is used to describe tumor infiltration alongside anatomical MRI and simulate the degree to which it modifies RT target planning. In 11 patients with glioblastoma, data from preRT sMRI scans were processed to give high-resolution, whole-brain metabolite maps normalized by contralateral white matter. Maps depicting choline to N-Acetylaspartate (Cho/NAA) ratios were registered to contrast-enhanced T1-weighted RT planning MRI for each patient. Volumes depicting metabolic abnormalities (1.5−, 1.75−, and 2.0-fold increases in Cho/NAA ratios) were compared with conventional target volumes and contrast-enhancing tumor at recurrence. sMRI-modified RT plans were generated to evaluate target volume coverage and organ-at-risk dose constraints. Conventional clinical target volumes and Cho/NAA abnormalities identified significantly different regions of microscopic infiltration with substantial Cho/NAA abnormalities falling outside of the conventional 60 Gy isodose line (41.1, 22.2, and 12.7 cm3, respectively). Clinical target volumes using Cho/NAA thresholds exhibited significantly higher coverage of contrast enhancement at recurrence on average (92.4%, 90.5%, and 88.6%, respectively) than conventional plans (82.5%). sMRI-based plans targeting tumor infiltration met planning objectives in all cases with no significant change in target coverage. In 2 cases, the sMRI-modified plan exhibited better coverage of contrast-enhancing tumor at recurrence than the original plan. Integration of the high-resolution, whole-brain sMRI into RT planning is feasible, resulting in RT target volumes that can effectively target tumor infiltration while adhering to conventional constraints. PMID:28105468
Zhang, Xiaodong; Zhao, Kuai-Le; Guerrero, Thomas M.; McGuire, Sean E.; Yaremko, Brian; Komaki, Ritsuko; Cox, James D.; Hui, Zhouguang; Li, Yupeng; Newhauser, Wayne D.; Mohan, Radhe; Liao, Zhongxing
2008-01-01
Purpose To compare three-dimensional (3D) and 4D computed tomography (CT)– based treatment plans for proton therapy or intensity-modulated radiation therapy (IMRT) for esophageal cancer in terms of doses to the lung, heart, and spinal cord and variations in target coverage and normal tissue sparing. Materials and Methods IMRT and proton plans for 15 patients with distal esophageal cancer were designed from the 3D average CT scans and then recalculated on 10 4D CT data sets. Dosimetric data were compared for tumor coverage and normal tissue sparing. Results Compared with IMRT, median lung volumes exposed to 5,10, and 20 Gy and mean lung dose were reduced by 35.6%, 20.5%,5.8%, and 5.1 Gy for a two-beam proton plan and by 17.4%,8.4%,5%, and 2.9 Gy for a three-beam proton plan. The greater lung sparing in the two-beam proton plan was achieved at the expense of less conformity to the target (conformity index CI=1.99) and greater irradiation of the heart (heart-V40=41.8%) compared with the IMRT plan(CI=1.55, heart-V40=35.7%) or the three-beam proton plan (CI=1.46, heart-V40=27.7%). Target coverage differed by more than 2% between the 3D and 4D plans for patients with substantial diaphragm motion in the three-beam proton and IMRT plans. The difference in spinal cord maximum dose between 3D and 4D plans could exceed 5 Gy for the proton plans partly owing to variations in stomach gas-filling. Conclusions Proton therapy provided significantly better sparing of lung than did IMRT. Diaphragm motion and stomach gas-filling must be considered in evaluating target coverage and cord doses. PMID:18722278
Zhang, Xiaodong; Zhao, Kuai-le; Guerrero, Thomas M; McGuire, Sean E; Yaremko, Brian; Komaki, Ritsuko; Cox, James D; Hui, Zhouguang; Li, Yupeng; Newhauser, Wayne D; Mohan, Radhe; Liao, Zhongxing
2008-09-01
To compare three-dimensional (3D) and four-dimensional (4D) computed tomography (CT)-based treatment plans for proton therapy or intensity-modulated radiation therapy (IMRT) for esophageal cancer in terms of doses to the lung, heart, and spinal cord and variations in target coverage and normal tissue sparing. The IMRT and proton plans for 15 patients with distal esophageal cancer were designed from the 3D average CT scans and then recalculated on 10 4D CT data sets. Dosimetric data were compared for tumor coverage and normal tissue sparing. Compared with IMRT, median lung volumes exposed to 5, 10, and 20 Gy and mean lung dose were reduced by 35.6%, 20.5%, 5.8%, and 5.1 Gy for a two-beam proton plan and by 17.4%, 8.4%, 5%, and 2.9 Gy for a three-beam proton plan. The greater lung sparing in the two-beam proton plan was achieved at the expense of less conformity to the target (conformity index [CI], 1.99) and greater irradiation of the heart (heart-V40, 41.8%) compared with the IMRT plan(CI, 1.55, heart-V40, 35.7%) or the three-beam proton plan (CI, 1.46, heart-V40, 27.7%). Target coverage differed by more than 2% between the 3D and 4D plans for patients with substantial diaphragm motion in the three-beam proton and IMRT plans. The difference in spinal cord maximum dose between 3D and 4D plans could exceed 5 Gy for the proton plans partly owing to variations in stomach gas filling. Proton therapy provided significantly better sparing of lung than did IMRT. Diaphragm motion and stomach gas-filling must be considered in evaluating target coverage and cord doses.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Yan, S; Depauw, N; Flanz, J
2016-06-15
Purpose: Gantry-less proton treatment facility could lower the capital cost of proton therapy. This study investigates the dosimetric feasibility of using only coplanar pencil beam scanning (PBS) beams for those patients who had beam angles that would not have been deliverable without the gantry. Those coplanar beams are implemented on gantry-less horizontal beam-line with patients in sitting or standing positions. Methods: We have selected ten patients (seven head-and-neck, one thoracic, one abdominal and one pelvic case) with clinically delivered double scattering (DS) or PBS treatment plans with beam angles that were challenging to achieve without a gantry. After removing thesemore » beams angles, PBS plans were optimized for gantry-less intensity modulated proton therapy (IMPT) or single field optimization (SFO) with multi-criteria optimization (MCO). For head-and-neck patients who were treated by DS, we generated PBS plans with non-coplanar beams for comparison. Dose-volume-histograms (DVHs), target homogeneity index (HI), mean dose, D-2 and D-98 were reported. Robustness analysis was performed with ±2.5 mm setup errors and ±3.5% range uncertainties for three head-and-neck patients. Results: PBS-gantry-less plans provided more homogenous target coverage and significant improvements on organs-at-risk (OARs) sparing, compared to passive scattering treatments with a gantry. The PBS gantry-less treatments reduced the HI for target coverage by 1.3% to 47.2%, except for a suprasellar patient and a liver patient. The PBS-gantry-less plans reduced the D-mean of OARs by 3.6% to 67.4%. The PBS-gantry plans had similar target coverage and only marginal improvements on OAR sparing as compared to the PBS-gantry-less plans. These two PBS plans also had similar robustness relative to range uncertainties and setup errors. Conclusion: The gantry-less plans have with less mean dose to OARs and more homogeneous target coverage. Although the PBS-gantry plans have slightly improved target coverage and OARs sparing, the overall benefit of having a gantry to provide non-coplanar beams is debatable.« less
Environmental metabarcodes for insects: in silico PCR reveals potential for taxonomic bias.
Clarke, Laurence J; Soubrier, Julien; Weyrich, Laura S; Cooper, Alan
2014-11-01
Studies of insect assemblages are suited to the simultaneous DNA-based identification of multiple taxa known as metabarcoding. To obtain accurate estimates of diversity, metabarcoding markers ideally possess appropriate taxonomic coverage to avoid PCR-amplification bias, as well as sufficient sequence divergence to resolve species. We used in silico PCR to compare the taxonomic coverage and resolution of newly designed insect metabarcodes (targeting 16S) with that of existing markers [16S and cytochrome oxidase c subunit I (COI)] and then compared their efficiency in vitro. Existing metabarcoding primers amplified in silico <75% of insect species with complete mitochondrial genomes available, whereas new primers targeting 16S provided >90% coverage. Furthermore, metabarcodes targeting COI appeared to introduce taxonomic PCR-amplification bias, typically amplifying a greater percentage of Lepidoptera and Diptera species, while failing to amplify certain orders in silico. To test whether bias predicted in silico was observed in vitro, we created an artificial DNA blend containing equal amounts of DNA from 14 species, representing 11 insect orders and one arachnid. We PCR-amplified the blend using five primer sets, targeting either COI or 16S, with high-throughput amplicon sequencing yielding more than 6 million reads. In vitro results typically corresponded to in silico PCR predictions, with newly designed 16S primers detecting 11 insect taxa present, thus providing equivalent or better taxonomic coverage than COI metabarcodes. Our results demonstrate that in silico PCR is a useful tool for predicting taxonomic bias in mixed template PCR and that researchers should be wary of potential bias when selecting metabarcoding markers. © 2014 John Wiley & Sons Ltd.
Gauer, Tobias; Sothmann, Thilo; Blanck, Oliver; Petersen, Cordula; Werner, René
2018-06-01
Radiotherapy of extracranial metastases changed from normofractioned 3D CRT to extreme hypofractionated stereotactic treatment using VMAT beam techniques. Random interaction between tumour motion and dynamically changing beam parameters might result in underdosage of the CTV even for an appropriately dimensioned ITV (interplay effect). This study presents a clinical scenario of extreme hypofractionated stereotactic treatment and analyses the impact of interplay effects on CTV dose coverage. For a thoracic/abdominal phantom with an integrated high-resolution detector array placed on a 4D motion platform, dual-arc treatment plans with homogenous target coverage were created using a common VMAT technique and delivered in a single fraction. CTV underdosage through interplay effects was investigated by comparing dose measurements with and without tumour motion during plan delivery. Our study agrees with previous works that pointed out insignificant interplay effects on target coverage for very regular tumour motion patterns like simple sinusoidal motion. However, we identified and illustrated scenarios that are likely to result in a clinically relevant CTV underdosage. For tumour motion with abnormal variability, target coverage quantified by the CTV area receiving more than 98% of the prescribed dose decreased to 78% compared to 100% at static dose measurement. This study is further proof of considerable influence of interplay effects on VMAT dose delivery in stereotactic radiotherapy. For selected conditions of an exemplary scenario, interplay effects and related motion-induced target underdosage primarily occurred in tumour motion pattern with increased motion variability and VMAT plan delivery using complex MLC dose modulation.
Kripke, Katharine; Samuelson, Julia; Schnure, Melissa; Dalal, Shona; Farley, Timothy; Hankins, Catherine; Thomas, Anne G.; Reed, Jason; Stegman, Peter; Bock, Naomi
2016-01-01
Background In 2007, the World Health Organization and the Joint United Nations Programme on HIV/AIDS (UNAIDS) identified 14 priority countries across eastern and southern Africa for scaling up voluntary medical male circumcision (VMMC) services. Several years into this effort, we reflect on progress. Methods Using the Decision Makers’ Program Planning Tool (DMPPT) 2.1, we assessed age-specific impact, cost-effectiveness, and coverage attributable to circumcisions performed through 2014. We also compared impact of actual progress to that of achieving 80% coverage among men ages 15–49 in 12 VMMC priority countries and Nyanza Province, Kenya. We populated the models with age-disaggregated VMMC service statistics and with population, mortality, and HIV incidence and prevalence projections exported from country-specific Spectrum/Goals files. We assumed each country achieved UNAIDS’ 90-90-90 treatment targets. Results More than 9 million VMMCs were conducted through 2014: 43% of the estimated 20.9 million VMMCs required to reach 80% coverage by the end of 2015. The model assumed each country reaches the UNAIDS targets, and projected that VMMCs conducted through 2014 will avert 240,000 infections by the end of 2025, compared to 1.1 million if each country had reached 80% coverage by the end of 2015. The median estimated cost per HIV infection averted was $4,400. Nyanza Province in Kenya, the 11 priority regions in Tanzania, and Uganda have reached or are approaching MC coverage targets among males ages 15–24, while coverage in other age groups is lower. Across all countries modeled, more than half of the projected HIV infections averted were attributable to circumcising 10- to 19-year-olds. Conclusions The priority countries have made considerable progress in VMMC scale-up, and VMMC remains a cost-effective strategy for epidemic impact, even assuming near-universal HIV diagnosis, treatment coverage, and viral suppression. Examining circumcision coverage by five-year age groups will inform countries’ decisions about next steps. PMID:27441648
Single-Isocenter Multiple-Target Stereotactic Radiosurgery: Risk of Compromised Coverage
DOE Office of Scientific and Technical Information (OSTI.GOV)
Roper, Justin, E-mail: justin.roper@emory.edu; Department of Biostatistics and Bioinformatics, Winship Cancer Institute of Emory University, Atlanta, Georgia; Chanyavanich, Vorakarn
2015-11-01
Purpose: To determine the dosimetric effects of rotational errors on target coverage using volumetric modulated arc therapy (VMAT) for multitarget stereotactic radiosurgery (SRS). Methods and Materials: This retrospective study included 50 SRS cases, each with 2 intracranial planning target volumes (PTVs). Both PTVs were planned for simultaneous treatment to 21 Gy using a single-isocenter, noncoplanar VMAT SRS technique. Rotational errors of 0.5°, 1.0°, and 2.0° were simulated about all axes. The dose to 95% of the PTV (D95) and the volume covered by 95% of the prescribed dose (V95) were evaluated using multivariate analysis to determine how PTV coverage was relatedmore » to PTV volume, PTV separation, and rotational error. Results: At 0.5° rotational error, D95 values and V95 coverage rates were ≥95% in all cases. For rotational errors of 1.0°, 7% of targets had D95 and V95 values <95%. Coverage worsened substantially when the rotational error increased to 2.0°: D95 and V95 values were >95% for only 63% of the targets. Multivariate analysis showed that PTV volume and distance to isocenter were strong predictors of target coverage. Conclusions: The effects of rotational errors on target coverage were studied across a broad range of SRS cases. In general, the risk of compromised coverage increased with decreasing target volume, increasing rotational error and increasing distance between targets. Multivariate regression models from this study may be used to quantify the dosimetric effects of rotational errors on target coverage given patient-specific input parameters of PTV volume and distance to isocenter.« less
A Max-Flow Based Algorithm for Connected Target Coverage with Probabilistic Sensors
Shan, Anxing; Xu, Xianghua; Cheng, Zongmao; Wang, Wensheng
2017-01-01
Coverage is a fundamental issue in the research field of wireless sensor networks (WSNs). Connected target coverage discusses the sensor placement to guarantee the needs of both coverage and connectivity. Existing works largely leverage on the Boolean disk model, which is only a coarse approximation to the practical sensing model. In this paper, we focus on the connected target coverage issue based on the probabilistic sensing model, which can characterize the quality of coverage more accurately. In the probabilistic sensing model, sensors are only be able to detect a target with certain probability. We study the collaborative detection probability of target under multiple sensors. Armed with the analysis of collaborative detection probability, we further formulate the minimum ϵ-connected target coverage problem, aiming to minimize the number of sensors satisfying the requirements of both coverage and connectivity. We map it into a flow graph and present an approximation algorithm called the minimum vertices maximum flow algorithm (MVMFA) with provable time complex and approximation ratios. To evaluate our design, we analyze the performance of MVMFA theoretically and also conduct extensive simulation studies to demonstrate the effectiveness of our proposed algorithm. PMID:28587084
A Max-Flow Based Algorithm for Connected Target Coverage with Probabilistic Sensors.
Shan, Anxing; Xu, Xianghua; Cheng, Zongmao; Wang, Wensheng
2017-05-25
Coverage is a fundamental issue in the research field of wireless sensor networks (WSNs). Connected target coverage discusses the sensor placement to guarantee the needs of both coverage and connectivity. Existing works largely leverage on the Boolean disk model, which is only a coarse approximation to the practical sensing model. In this paper, we focus on the connected target coverage issue based on the probabilistic sensing model, which can characterize the quality of coverage more accurately. In the probabilistic sensing model, sensors are only be able to detect a target with certain probability. We study the collaborative detection probability of target under multiple sensors. Armed with the analysis of collaborative detection probability, we further formulate the minimum ϵ -connected target coverage problem, aiming to minimize the number of sensors satisfying the requirements of both coverage and connectivity. We map it into a flow graph and present an approximation algorithm called the minimum vertices maximum flow algorithm (MVMFA) with provable time complex and approximation ratios. To evaluate our design, we analyze the performance of MVMFA theoretically and also conduct extensive simulation studies to demonstrate the effectiveness of our proposed algorithm.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Cheon, G; Kang, Y; Kang, S
Purpose: Hippocampus is one of the important organs which controls emotions, behaviors, movements the memorizing and learning ability. In the conventional head & neck therapy position, it is difficult to perform the hippocampal-sparing brain radiation therapy. The purpose of this study is to investigate optimal head angle which can save the hippocampal-sparing and organ at risk (OAR) in conformal radiation therapy (CRT), Intensity modulation radiation therapy (IMRT) and helical tomotherapy (HT). Methods: Three types of radiation treatment plans, CRT, IMRT and Tomotherapy plans, were performed for 10 brain tumor patients. The image fusion between CT and MRI data were usedmore » in the contour due to the limited delineation of the target and OAR in the CT scan. The optimal condition plan was determined by comparing the dosimetric performance of the each plan with the use of various parameters which include three different techniques (CRT, IMRT, HT) and 4 angle (0, 15, 30, 40 degree). The each treatment plans of three different techniques were compared with the following parameters: conformity index (CI), homogeneity index (HI), target coverage, dose in the OARs, monitor units (MU), beam on time and the normal tissue complication probability (NTCP). Results: HI, CI and target coverage was most excellent in head angle 30 degree among all angle. When compared by modality, target coverage and CI showed good results in IMRT and TOMO than compared to the CRT. HI at the head angle 0 degrees is 1.137±0.17 (CRT), 1.085±0.09 (IMRT) and 1.077±0.06 (HT). HI at the head angle 30 degrees is 1.056±0.08 (CRT), 1.020±0.05 (IMRT) and 1.022±0.07 (HT). Conclusion: The results of our study show that when head angle tilted at 30 degree, target coverage, HI, CI were improved, and the dose delivered to OAR was reduced compared with conventional supine position in brain radiation therapy. This work was supported by the Radiation Technology R&D program (No. 2013M2A2A7043498) and the Mid-career Researcher Program (2014R1A2A1A10050270) through the National Research Foundation of Korea funded by the Ministry of Science, ICT&Future Planning.« less
Liu, Chenbin; Schild, Steven E; Chang, Joe Y; Liao, Zhongxing; Korte, Shawn; Shen, Jiajian; Ding, Xiaoning; Hu, Yanle; Kang, Yixiu; Keole, Sameer R; Sio, Terence T; Wong, William W; Sahoo, Narayan; Bues, Martin; Liu, Wei
2018-06-01
To investigate how spot size and spacing affect plan quality, robustness, and interplay effects of robustly optimized intensity modulated proton therapy (IMPT) for lung cancer. Two robustly optimized IMPT plans were created for 10 lung cancer patients: first by a large-spot machine with in-air energy-dependent large spot size at isocenter (σ: 6-15 mm) and spacing (1.3 σ), and second by a small-spot machine with in-air energy-dependent small spot size (σ: 2-6 mm) and spacing (5 mm). Both plans were generated by optimizing radiation dose to internal target volume on averaged 4-dimensional computed tomography scans using an in-house-developed IMPT planning system. The dose-volume histograms band method was used to evaluate plan robustness. Dose evaluation software was developed to model time-dependent spot delivery to incorporate interplay effects with randomized starting phases for each field per fraction. Patient anatomy voxels were mapped phase-to-phase via deformable image registration, and doses were scored using in-house-developed software. Dose-volume histogram indices, including internal target volume dose coverage, homogeneity, and organs at risk (OARs) sparing, were compared using the Wilcoxon signed-rank test. Compared with the large-spot machine, the small-spot machine resulted in significantly lower heart and esophagus mean doses, with comparable target dose coverage, homogeneity, and protection of other OARs. Plan robustness was comparable for targets and most OARs. With interplay effects considered, significantly lower heart and esophagus mean doses with comparable target dose coverage and homogeneity were observed using smaller spots. Robust optimization with a small spot-machine significantly improves heart and esophagus sparing, with comparable plan robustness and interplay effects compared with robust optimization with a large-spot machine. A small-spot machine uses a larger number of spots to cover the same tumors compared with a large-spot machine, which gives the planning system more freedom to compensate for the higher sensitivity to uncertainties and interplay effects for lung cancer treatments. Copyright © 2018 Elsevier Inc. All rights reserved.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Ashenafi, M; McDonald, D; Peng, J
Purpose: Improved patient imaging used for planning the treatment of cervical cancer with Tandem and Ovoid (T&O) Intracavitary high-dose-rate brachytherapy (HDR) now allows for 3D delineation of target volumes and organs-at-risk. However, historical data relies on the conventional point A-based planning technique. A comparative dosimetric study was performed by generating both target-based (TBP) and point-based (PBP) plans for ten clinical patients. Methods: Treatment plans created using Elekta Oncentra v. 4.3 for ten consecutive cervical cancer patients were analyzed. All patients were treated with HDR using the Utrecht T&O applicator. Both CT and MRI imaging modalities were utilized to delineate clinicalmore » target volume (CTV) and organs-at-risk (rectum, sigmoid, bladder, and small bowel). Point A (left and right), vaginal mucosa, and ICRU rectum and bladder points were defined on CT. Two plans were generated for each patient using two prescription methods (PBP and TBP). 7Gy was prescribed to each point A for each PBP plan and to the target D90% for each TBP plan. Target V90%, V100%, and V200% were evaluated. In addition, D0.1cc and D2cc were analyzed for each organ-at-risk. Differences were assessed for statistical significance (p<0.05) by use of Student’s t-test. Results: Target coverage was comparable for both planning methods, with each method providing adequate target coverage. TBP showed lower absolute dose to the target volume than PBP (D90% = 7.0Gy vs. 7.4Gy, p=0.028), (V200% = 10.9cc vs. 12.8cc, p=0.014), (ALeft = 6.4Gy vs. 7Gy, p=0.009), and (ARight = 6.4Gy vs. 7Gy, p=0.013). TBP also showed a statistically significant reduction in bladder, rectum, small bowel, and sigmoid doses compared to PBP. There was no statistically significant difference in vaginal mucosa or ICRU-defined rectum and bladder dose. Conclusion: Target based prescription resulted in substantially lower dose to delineated organs-at-risk compared to point based prescription, while maintaining similar target coverage.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Hansen, Anders T., E-mail: andehans@rm.dk; Lukacova, Slavka; Lassen-Ramshad, Yasmin
2015-01-01
When standard conformal x-ray technique for craniospinal irradiation is used, it is a challenge to achieve satisfactory dose coverage of the target including the area of the cribriform plate, while sparing organs at risk. We present a new intensity-modulated radiation therapy (IMRT), noncoplanar technique, for delivering irradiation to the cranial part and compare it with 3 other techniques and previously published results. A total of 13 patients who had previously received craniospinal irradiation with standard conformal x-ray technique were reviewed. New treatment plans were generated for each patient using the noncoplanar IMRT-based technique, a coplanar IMRT-based technique, and a coplanarmore » volumetric-modulated arch therapy (VMAT) technique. Dosimetry data for all patients were compared with the corresponding data from the conventional treatment plans. The new noncoplanar IMRT technique substantially reduced the mean dose to organs at risk compared with the standard radiation technique. The 2 other coplanar techniques also reduced the mean dose to some of the critical organs. However, this reduction was not as substantial as the reduction obtained by the noncoplanar technique. Furthermore, compared with the standard technique, the IMRT techniques reduced the total calculated radiation dose that was delivered to the normal tissue, whereas the VMAT technique increased this dose. Additionally, the coverage of the target was significantly improved by the noncoplanar IMRT technique. Compared with the standard technique, the coplanar IMRT and the VMAT technique did not improve the coverage of the target significantly. All the new planning techniques increased the number of monitor units (MU) used—the noncoplanar IMRT technique by 99%, the coplanar IMRT technique by 122%, and the VMAT technique by 26%—causing concern for leak radiation. The noncoplanar IMRT technique covered the target better and decreased doses to organs at risk compared with the other techniques. All the new techniques increased the number of MU compared with the standard technique.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Sugar, E Neubauer; Buzurovic, I; O’Farrell, D
2015-06-15
Purpose: To compare the dosimetry of a standard rectilinear and an adaptive technique used in I125 prostate seed implants. Methods: To achieve favorable dosimetry in prostate implants we used adaptive needle updates to match actual positions in real-time. The seed locations were optimized based on actual needle locations. The seeds were delivered automatically with a robotic device seedSelectron™ (Elekta Brachytherapy). In this study, we evaluated the former approach against the standard rectilinear technique in which the needles have a parallel distribution. The treatment plans for 10 patients were analyzed. For comparison, the actual treatment plans were revised so each needlemore » was repositioned to its original parallel location through the template. The analysis was performed by comparing the target coverage and dose to the organs at risk. The comparison was done using the following planning goals: the target D90> 90%, V100% > 90%, V50% <70% and V200% <30%; the urethra V125% < 1cm3 and V150%= 0cm3; and the Rectum V100%<1cm3 and V69% < 8cm3. The prescription dose to the target was 145Gy. Results: The average target volume and number of seeds were 44.39cm3(SD=11.14) and 74(SD=12), respectively. The D90 for adaptive and rectilinear plans was 159.9Gy(SD=2.99) and 155.53Gy(SD=4.04) resulting in a 2.74% difference for the average target coverage. A similar difference (1.75%) was noticed in the target V100[%]. No significant difference was noticed in the dose to the urethra and rectum. All planning goals were met with both the adaptive and rectilinear approach for each plan. Conclusion: The study reveals enhanced coverage of the target when using the adaptive needle adjustments as compared to the rectilinear approach for the analyzed cases. However, the differences in dosimetry did not translate to meaningful clinical outcomes.« less
Cho, Jungwoo; You, Myoungsoon; Yoon, Yoonjin
2017-01-01
In highly urbanized area where traffic condition fluctuates constantly, transportation infrastructure is one of the major contributing factors to Emergency Medical Service (EMS) availability and patient outcome. In this paper, we assess the impact of traffic fluctuation to the EMS first response availability in urban area, by evaluating the k-minute coverage under 21 traffic scenarios. The set of traffic scenarios represents the time-of-day and day-of-week effects, and is generated by combining road link speed information from multiple historical speed databases. In addition to the k-minute area coverage calculation, the k-minute population coverage is also evaluated for every 100m by 100m grid that partitions the case study area of Seoul, South Korea. In the baseline case of traveling at the speed limit, both the area and population coverage reached nearly 100% when compared to the five-minute travel time national target. Employing the proposed LoST (Loss of Serviceability due to Traffic) index, which measures coverage reduction in percentage compared to the baseline case, we find that the citywide average LoST for area and population coverage are similar at 34.2% and 33.8%. However, district-wise analysis reveals that such reduction varies significantly by district, and the magnitude of area and population coverage reduction is not always proportional. We conclude that the effect of traffic variation is significant to successful urban EMS first response performance, and regional variation is evident among local districts. Complexity in the urban environment requires a more adaptive approach in public health resource management and EMS performance target determination.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Lens, Eelco, E-mail: e.lens@amc.uva.nl; Horst, Astrid van der; Versteijne, Eva
2015-07-01
Purpose: The midventilation (midV) approach can be used to take respiratory-induced pancreatic tumor motion into account during radiation therapy. In this study, the dosimetric consequences for organs at risk and tumor coverage of using a midV approach compared with using an internal target volume (ITV) were investigated. Methods and Materials: For each of the 18 patients, 2 treatment plans (25 × 2.0 Gy) were created, 1 using an ITV and 1 using a midV approach. The midV dose distribution was blurred using the respiratory-induced motion from 4-dimensional computed tomography. The resulting planning target volume (PTV) coverage for this blurred dosemore » distribution was analyzed; PTV coverage was required to be at least V{sub 95%} >98%. In addition, the change in PTV size and the changes in V{sub 10Gy}, V{sub 20Gy}, V{sub 30Gy}, V{sub 40Gy}, D{sub mean} and D{sub 2cc} for the stomach and for the duodenum were analyzed; differences were tested for significance using the Wilcoxon signed-rank test. Results: Using a midV approach resulted in sufficient target coverage. A highly significant PTV size reduction of 13.9% (P<.001) was observed. Also, all dose parameters for the stomach and duodenum, except the D{sub 2cc} of the duodenum, improved significantly (P≤.002). Conclusions: By using the midV approach to account for respiratory-induced tumor motion, a significant PTV reduction and significant dose reductions to the stomach and to the duodenum can be achieved when irradiating pancreatic tumors.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Jin, L; Fan, J; Eldib, A
Purpose: Treating nose skin with an electron beam is of a substantial challenge due to uneven nose surfaces and tissue heterogeneity, and consequently could have a great uncertainty of dose accuracy on the target. This work explored the method using Monte Carlo (MC)-based energy and intensity modulated electron radiotherapy (MERT), which would be delivered with a photon MLC in a standard medical linac (Artiste). Methods: The traditional treatment on the nose skin involves the usage of a bolus, often with a single energy electron beam. This work avoided using the bolus, and utilized mixed energies of electron beams. An in-housemore » developed Monte Carlo (MC)-based dose calculation/optimization planning system was employed for treatment planning. Phase space data (6, 9, 12 and 15 MeV) were used as an input source for MC dose calculations for the linac. To reduce the scatter-caused penumbra, a short SSD (61 cm) was used. A clinical case of the nose skin, which was previously treated with a single 9 MeV electron beam, was replanned with the MERT method. The resultant dose distributions were compared with the plan previously clinically used. The dose volume histogram of the MERT plan is calculated to examine the coverage of the planning target volume (PTV) and critical structure doses. Results: The target coverage and conformality in the MERT plan are improved as compared to the conventional plan. The MERT can provide more sufficient target coverage and less normal tissue dose underneath the nose skin. Conclusion: Compared to the conventional treatment technique, using MERT for the nose skin treatment has shown the dosimetric advantages in the PTV coverage and conformality. In addition, this technique eliminates the necessity of the cutout and bolus, which makes the treatment more efficient and accurate.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Yang, Jun; Department of Oncology, First Affiliated Hospital of Xinxiang Medical University, 88 Jiankang Road, Weihui, Henan, 453100; Ma, Lin
2016-07-01
To investigate the dosimetric characteristics of 4 SBRT-capable dose delivery systems, CyberKnife (CK), Helical TomoTherapy (HT), Volumetric Modulated Arc Therapy (VMAT) by Varian RapidArc (RA), and segmental step-and-shoot intensity-modulated radiation therapy (IMRT) by Elekta, on isolated thoracic spinal lesions. CK, HT, RA, and IMRT planning were performed simultaneously for 10 randomly selected patients with 6 body types and 6 body + pedicle types with isolated thoracic lesions. The prescription was set with curative intent and dose of either 33 Gy in 3 fractions (3F) or 40 Gy in 5F to cover at least 90% of the planning target volume (PTV),more » correspondingly. Different dosimetric indices, beam-on time, and monitor units (MUs) were evaluated to compare the advantages/disadvantages of each delivery modality. In ensuring the dose-volume constraints for cord and esophagus of the premise, CK, HT, and RA all achieved a sharp conformity index (CI) and a small penumbra volume compared to IMRT. RA achieved a CI comparable to those from CK, HT, and IMRT. CK had a heterogeneous dose distribution in the target as its radiosurgical nature with less dose uniformity inside the target. CK had the longest beam-on time and the largest MUs, followed by HT and RA. IMRT presented the shortest beam-on time and the least MUs delivery. For the body-type lesions, CK, HT, and RA satisfied the target coverage criterion in 6 cases, but the criterion was satisfied in only 3 (50%) cases with the IMRT technique. For the body + pedicle-type lesions, HT satisfied the criterion of the target coverage of ≥90% in 4 of the 6 cases, and reached a target coverage of 89.0% in another case. However, the criterion of the target coverage of ≥90% was reached in 2 cases by CK and RA, and only in 1 case by IMRT. For curative-intent SBRT of isolated thoracic spinal lesions, RA is the first choice for the body-type lesions owing to its delivery efficiency (time); the second choice is CK or HT; HT is the preferential choice for the body + pedicle-type lesions. This study suggests further clinical investigations with longer follow-up for these studied cases.« less
Restricted Field IMRT Dramatically Enhances IMRT Planning for Mesothelioma
DOE Office of Scientific and Technical Information (OSTI.GOV)
Allen, Aaron M.; Schofield, Deborah; Hacker, Fred
2007-12-01
Purpose: To improve the target coverage and normal tissue sparing of intensity-modulated radiotherapy (IMRT) for mesothelioma after extrapleural pneumonectomy. Methods and Materials: Thirteen plans from patients previously treated with IMRT for mesothelioma were replanned using a restricted field technique. This technique was novel in two ways. It limited the entrance beams to 200{sup o} around the target and three to four beams per case had their field apertures restricted down to the level of the heart or liver to further limit the contralateral lung dose. New constraints were added that included a mean lung dose of <9.5 Gy and volumemore » receiving {>=}5 Gy of <55%. Results: In all cases, the planning target volume coverage was excellent, with an average of 97% coverage of the planning target volume by the target dose. No change was seen in the target coverage with the new technique. The heart, kidneys, and esophagus were all kept under tolerance in all cases. The average mean lung dose, volume receiving {>=}20 Gy, and volume receiving {>=}5 Gy with the new technique was 6.6 Gy, 3.0%, and 50.8%, respectively, compared with 13.8 Gy, 15%, and 90% with the previous technique (p < 0.0001 for all three comparisons). The maximal value for any case in the cohort was 8.0 Gy, 7.3%, and 57.5% for the mean lung dose, volume receiving {>=}20 Gy, and volume receiving {>=}5 Gy, respectively. Conclusion: Restricted field IMRT provides an improved method to deliver IMRT to a complex target after extrapleural pneumonectomy. An upcoming Phase I trial will provide validation of these results.« less
Uninsurance, underinsurance, and health care utilization in Mexico by US border residents.
Su, Dejun; Pratt, William; Stimpson, Jim P; Wong, Rebeca; Pagán, José A
2014-08-01
Using data from the 2008 Cross-Border Utilization of Health Care Survey, we examined the relationship between United States (US) health insurance coverage plans and the use of health care services in Mexico by US residents of the US-Mexico border region. We found immigrants were far more likely to be uninsured than their native-born counterparts (63 vs. 27.8 %). Adults without health insurance coverage were more likely to purchase medications or visit physicians in Mexico compared to insured adults. However, adults with Medicaid coverage were more likely to visit dentists in Mexico compared to uninsured adults. Improving health care access for US residents in the southwestern border region of the country will require initiatives that target not only providing coverage to the large uninsured population but also improving access to health care services for the large underinsured population.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Galavis, P; Barbee, D; Jozsef, G
2016-06-15
Purpose: Prone accelerated partial breast irradiation (APBI) results in dose reduction to the heart and lung. Flattening filter free beams (FFF) reduce out of field dose due to the reduced scatter from the removal of the flattening filter and reduce the buildup region. The aim of this work is to evaluate the dosimetric advantages of FFF beams to prone APBI target coverage and reduction in dose to organs at risk. Methods: Fifteen clinical prone APBI cases using flattened photon beams were retrospectively re-planned in Eclipse-TPS using FFF beams. FFF plans were designed to provide equivalent target coverage with similar hotspotsmore » using the same field arrangements, resulting in comparable target DVHs. Both plans were transferred to a prone breast phantom and delivered on Varian-Edge-Linac. GafChromic-film was placed in the coronal plane of the phantom, partially overlapping the treatment field and extending into OARs to compare dose profiles from both plans. Results: FFF plans were comparable to the clinical plans with maximum doses of (108.3±2.3)% and (109.2±2.4)% and mean doses of (104.5±1.0)% and (104.6±1.2)%, respectively. Similar mean dose doses to the heart and contralateral lungs were observed from both plans, whereas the mean dose to the contra-lateral breast was (2.79±1.18) cGy and (2.86±1.40) cGy for FFF and clinical plans respectively. However for both plans the error between calculated and measured doses at 4 cm from the field edge was 10%. Conclusion: The results showed that FFF beams in prone APBI provide dosimetrically equivalent target coverage and improved coverage in superficial target due to softer energy spectra. Film analysis showed that the TPS underestimates dose outside field edges for both cases. The FFF measured plans showed less dose outside the beam that might reduce the probability of secondary cancers in the contralateral breast.« less
NASA Astrophysics Data System (ADS)
Howard, Ward S.; Law, Nicholas M.; Ziegler, Carl A.; Baranec, Christoph; Riddle, Reed
2018-02-01
Adaptive optics laser guide-star systems perform atmospheric correction of stellar wavefronts in two parts: stellar tip-tilt and high-spatial-order laser correction. The requirement of a sufficiently bright guide star in the field-of-view to correct tip-tilt limits sky coverage. In this paper, we show an improvement to effective seeing without the need for nearby bright stars, enabling full sky coverage by performing only laser-assisted wavefront correction. We used Robo-AO, the first robotic AO system, to comprehensively demonstrate this laser-only correction. We analyze observations from four years of efficient robotic operation covering 15000 targets and 42000 observations, each realizing different seeing conditions. Using an autoguider (or a post-processing software equivalent) and the laser to improve effective seeing independent of the brightness of a target, Robo-AO observations show a 39% ± 19% improvement to effective FWHM, without any tip-tilt correction. We also demonstrate that 50% encircled energy performance without tip-tilt correction remains comparable to diffraction-limited, standard Robo-AO performance. Faint-target science programs primarily limited by 50% encircled energy (e.g., those employing integral field spectrographs placed behind the AO system) may see significant benefits to sky coverage from employing laser-only AO.
Racial and Ethnic Disparities in Services and the Patient Protection and Affordable Care Act
Abdus, Salam; Mistry, Kamila B.
2015-01-01
Objectives. We examined prereform patterns in insurance coverage, access to care, and preventive services use by race/ethnicity in adults targeted by the coverage expansions of the Patient Protection and Affordable Care Act (ACA). Methods. We used pre-ACA household data from the Medical Expenditure Panel Survey to identify groups targeted by the coverage provisions of the Act (Medicaid expansions and subsidized Marketplace coverage). We examined racial/ethnic differences in coverage, access to care, and preventive service use, across and within ACA relevant subgroups from 2005 to 2010. The study took place at the Agency for Healthcare Research and Quality in Rockville, Maryland. Results. Minorities were disproportionately represented among those targeted by the coverage provisions of the ACA. Targeted groups had lower rates of coverage, access to care, and preventive services use, and racial/ethnic disparities were, in some cases, widest within these targeted groups. Conclusions. Our findings highlighted the opportunity of the ACA to not only to improve coverage, access, and use for all racial/ethnic groups, but also to narrow racial/ethnic disparities in these outcomes. Our results might have particular importance for states that are deciding whether to implement the ACA Medicaid expansions. PMID:26447920
Racial and Ethnic Disparities in Services and the Patient Protection and Affordable Care Act.
Abdus, Salam; Mistry, Kamila B; Selden, Thomas M
2015-11-01
We examined prereform patterns in insurance coverage, access to care, and preventive services use by race/ethnicity in adults targeted by the coverage expansions of the Patient Protection and Affordable Care Act (ACA). We used pre-ACA household data from the Medical Expenditure Panel Survey to identify groups targeted by the coverage provisions of the Act (Medicaid expansions and subsidized Marketplace coverage). We examined racial/ethnic differences in coverage, access to care, and preventive service use, across and within ACA relevant subgroups from 2005 to 2010. The study took place at the Agency for Healthcare Research and Quality in Rockville, Maryland. Minorities were disproportionately represented among those targeted by the coverage provisions of the ACA. Targeted groups had lower rates of coverage, access to care, and preventive services use, and racial/ethnic disparities were, in some cases, widest within these targeted groups. Our findings highlighted the opportunity of the ACA to not only to improve coverage, access, and use for all racial/ethnic groups, but also to narrow racial/ethnic disparities in these outcomes. Our results might have particular importance for states that are deciding whether to implement the ACA Medicaid expansions.
TU-AB-BRB-00: New Methods to Ensure Target Coverage
DOE Office of Scientific and Technical Information (OSTI.GOV)
NONE
2015-06-15
The accepted clinical method to accommodate targeting uncertainties inherent in fractionated external beam radiation therapy is to utilize GTV-to-CTV and CTV-to-PTV margins during the planning process to design a PTV-conformal static dose distribution on the planning image set. Ideally, margins are selected to ensure a high (e.g. >95%) target coverage probability (CP) in spite of inherent inter- and intra-fractional positional variations, tissue motions, and initial contouring uncertainties. Robust optimization techniques, also known as probabilistic treatment planning techniques, explicitly incorporate the dosimetric consequences of targeting uncertainties by including CP evaluation into the planning optimization process along with coverage-based planning objectives. Themore » treatment planner no longer needs to use PTV and/or PRV margins; instead robust optimization utilizes probability distributions of the underlying uncertainties in conjunction with CP-evaluation for the underlying CTVs and OARs to design an optimal treated volume. This symposium will describe CP-evaluation methods as well as various robust planning techniques including use of probability-weighted dose distributions, probability-weighted objective functions, and coverage optimized planning. Methods to compute and display the effect of uncertainties on dose distributions will be presented. The use of robust planning to accommodate inter-fractional setup uncertainties, organ deformation, and contouring uncertainties will be examined as will its use to accommodate intra-fractional organ motion. Clinical examples will be used to inter-compare robust and margin-based planning, highlighting advantages of robust-plans in terms of target and normal tissue coverage. Robust-planning limitations as uncertainties approach zero and as the number of treatment fractions becomes small will be presented, as well as the factors limiting clinical implementation of robust planning. Learning Objectives: To understand robust-planning as a clinical alternative to using margin-based planning. To understand conceptual differences between uncertainty and predictable motion. To understand fundamental limitations of the PTV concept that probabilistic planning can overcome. To understand the major contributing factors to target and normal tissue coverage probability. To understand the similarities and differences of various robust planning techniques To understand the benefits and limitations of robust planning techniques.« less
Is universal health coverage the practical expression of the right to health care?
Ooms, Gorik; Latif, Laila A; Waris, Attiya; Brolan, Claire E; Hammonds, Rachel; Friedman, Eric A; Mulumba, Moses; Forman, Lisa
2014-02-24
The present Millennium Development Goals are set to expire in 2015 and their next iteration is now being discussed within the international community. With regards to health, the World Health Organization proposes universal health coverage as a 'single overarching health goal' for the next iteration of the Millennium Development Goals.The present Millennium Development Goals have been criticised for being 'duplicative' or even 'competing alternatives' to international human rights law. The question then arises, if universal health coverage would indeed become the single overarching health goal, replacing the present health-related Millennium Development Goals, would that be more consistent with the right to health? The World Health Organization seems to have anticipated the question, as it labels universal health coverage as "by definition, a practical expression of the concern for health equity and the right to health".Rather than waiting for the negotiations to unfold, we thought it would be useful to verify this contention, using a comparative normative analysis. We found that--to be a practical expression of the right to health--at least one element is missing in present authoritative definitions of universal health coverage: a straightforward confirmation that international assistance is essential, not optional.But universal health coverage is a 'work in progress'. A recent proposal by the United Nations Sustainable Development Solutions Network proposed universal health coverage with a set of targets, including a target for international assistance, which would turn universal health coverage into a practical expression of the right to health care.
Encaoua, J; Abgral, R; Leleu, C; El Kabbaj, O; Caradec, P; Bourhis, D; Pradier, O; Schick, U
2017-06-01
To study the impact on radiotherapy planning of an automatically segmented target volume delineation based on ( 18 F)-fluorodeoxy-D-glucose (FDG)-hybrid positron emission tomography-computed tomography (PET-CT) compared to a manually delineation based on computed tomography (CT) in oesophageal carcinoma patients. Fifty-eight patients diagnosed with oesophageal cancer between September 2009 and November 2014 were included. The majority had squamous cell carcinoma (84.5 %), and advanced stage (37.9 % were stade IIIA) and 44.8 % had middle oesophageal lesion. Gross tumour volumes were retrospectively defined based either manually on CT or automatically on coregistered PET/CT images using three different threshold methods: standard-uptake value (SUV) of 2.5, 40 % of maximum intensity and signal-to-background ratio. Target volumes were compared in length, volume and using the index of conformality. Radiotherapy plans to the dose of 50Gy and 66Gy using intensity-modulated radiotherapy were generated and compared for both data sets. Planification target volume coverage and doses delivered to organs at risk (heart, lung and spinal cord) were compared. The gross tumour volume based manually on CT was significantly longer than that automatically based on signal-to-background ratio (6.4cm versus 5.3cm; P<0.008). Doses to the lungs (V20, D mean ), heart (V40), and spinal cord (D max ) were significantly lower on plans using the PTV SBR . The PTV SBR coverage was statistically better than the PTV CT coverage on both plans. (50Gy: P<0.0004 and 66Gy: P<0.0006). The automatic PET segmentation algorithm based on the signal-to-background ratio method for the delineation of oesophageal tumours is interesting, and results in better target volume coverage and decreased dose to organs at risk. This may allow dose escalation up to 66Gy to the gross tumour volume. Copyright © 2017 Société française de radiothérapie oncologique (SFRO). Published by Elsevier SAS. All rights reserved.
Liu, Wei; Schild, Steven E.; Chang, Joe Y.; Liao, Zhongxing; Chang, Yu-Hui; Wen, Zhifei; Shen, Jiajian; Stoker, Joshua B.; Ding, Xiaoning; Hu, Yanle; Sahoo, Narayan; Herman, Michael G.; Vargas, Carlos; Keole, Sameer; Wong, William; Bues, Martin
2015-01-01
Background To compare the impact of uncertainties and interplay effect on 3D and 4D robustly optimized intensity-modulated proton therapy (IMPT) plans for lung cancer in an exploratory methodology study. Methods IMPT plans were created for 11 non-randomly selected non-small-cell lung cancer (NSCLC) cases: 3D robustly optimized plans on average CTs with internal gross tumor volume density overridden to irradiate internal target volume, and 4D robustly optimized plans on 4D CTs to irradiate clinical target volume (CTV). Regular fractionation (66 Gy[RBE] in 33 fractions) were considered. In 4D optimization, the CTV of individual phases received non-uniform doses to achieve a uniform cumulative dose. The root-mean-square-dose volume histograms (RVH) measured the sensitivity of the dose to uncertainties, and the areas under the RVH curve (AUCs) were used to evaluate plan robustness. Dose evaluation software modeled time-dependent spot delivery to incorporate interplay effect with randomized starting phases of each field per fraction. Dose-volume histogram indices comparing CTV coverage, homogeneity, and normal tissue sparing were evaluated using Wilcoxon signed-rank test. Results 4D robust optimization plans led to smaller AUC for CTV (14.26 vs. 18.61 (p=0.001), better CTV coverage (Gy[RBE]) [D95% CTV: 60.6 vs 55.2 (p=0.001)], and better CTV homogeneity [D5%–D95% CTV: 10.3 vs 17.7 (p=0.002)] in the face of uncertainties. With interplay effect considered, 4D robust optimization produced plans with better target coverage [D95% CTV: 64.5 vs 63.8 (p=0.0068)], comparable target homogeneity, and comparable normal tissue protection. The benefits from 4D robust optimization were most obvious for the 2 typical stage III lung cancer patients. Conclusions Our exploratory methodology study showed that, compared to 3D robust optimization, 4D robust optimization produced significantly more robust and interplay-effect-resistant plans for targets with comparable dose distributions for normal tissues. A further study with a larger and more realistic patient population is warranted to generalize the conclusions. PMID:26725727
SU-E-T-333: Dosimetric Impact of Rotational Error On the Target Coverage in IMPT Lung Cancer Plans
DOE Office of Scientific and Technical Information (OSTI.GOV)
Rana, S; Zheng, Y
2015-06-15
Purpose: The main purpose of this study was to investigate the impact of rotational (yaw, roll, and pitch) error on the planning target volume (PTV) coverage in lung cancer plans generated by intensity modulated proton therapy (IMPT). Methods: In this retrospective study, computed tomography (CT) dataset of previously treated lung case was used. IMPT plan were generated on the original CT dataset using left-lateral (LL) and posterior-anterior (PA) beams for a total dose of 74 Gy[RBE] with 2 Gy[RBE] per fraction. In order to investigate the dosimetric impact of rotational error, 12 new CT datasets were generated by re-sampling themore » original CT dataset for rotational (roll, yaw, and pitch) angles ranged from −5° to +5°, with an increment of 2.5°. A total of 12 new IMPT plans were generated based on the re-sampled CT datasets using beam parameters identical to the ones in the original IMPT plan. All treatment plans were generated in XiO treatment planning system. The PTV coverage (i.e., dose received by 95% of the PTV volume, D95) in new IMPT plans were then compared with the PTV coverage in the original IMPT plan. Results: Rotational errors caused the reduction in the PTV coverage in all 12 new IMPT plans when compared to the original IMPT lung plan. Specifically, the PTV coverage was reduced by 4.94% to 50.51% for yaw, by 4.04% to 23.74% for roll, and by 5.21% to 46.88% for pitch errors. Conclusion: Unacceptable dosimetric results were observed in new IMPT plans as the PTV coverage was reduced by up to 26.87% and 50.51% for rotational error of 2.5° and 5°, respectively. Further investigation is underway in evaluating the PTV coverage loss in the IMPT lung cancer plans for smaller rotational angle change.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Sherertz, T; Ellis, R; Colussi, V
2014-06-15
Purpose: To evaluate volumetric coverage of a Mick Radionuclear titanium Split-Ring applicator (SRA) with/without interstitial needle compared to an intracavitary Vienna applicator (VA), interstitial-intracavitary VA, and intracavitary ring and tandem applicator (RTA). Methods: A 57 year-old female with FIGO stage IIB cervical carcinoma was treated following chemoradiotherapy (45Gy pelvic and 5.4Gy parametrial boost) with highdose- rate (HDR) brachytherapy to 30Gy in 5 fractions using a SRA. A single interstitial needle was placed using the Ellis Interstitial Cap for the final three fractions to increase coverage of left-sided gross residual disease identified on 3T-MRI. High-risk (HR) clinical target volume (CTV) andmore » intermediate-risk (IR) CTV were defined using axial T2-weighted 2D and 3D MRI sequences (Philips PET/MRI unit). Organs-at-risks (OARs) were delineated on CT. Oncentra planning system was used for treatment optimization satisfying GEC-ESTRO guidelines for target coverage and OAR constraints. Retrospectively, treatment plans (additional 20 plans) were simulated using intracavitary SRA (without needle), intracavitary VA (without needle), interstitial-intracavitary VA, and intracavitary RTA with this same patient case. Plans were optimized for each fraction to maintain coverage to HR-CTV. Results: Interstitial-intracavitary SRA achieved the following combined coverage for external radiation and brachytherapy (EQD2): D90 HR-CTV =94.6Gy; Bladder-2cc =88.9Gy; Rectum-2cc =65.1Gy; Sigmoid-2cc =48.9Gy; Left vaginal wall (VW) =103Gy, Right VW =99.2Gy. Interstitial-intracavitary VA was able to achieve identical D90 HR-CTV =94.6Gy, yet Bladder-2cc =91.9Gy (exceeding GEC-ESTRO recommendations of 2cc<90Gy) and Left VW =120.8Gy and Right VW =115.5Gy. Neither the SRA nor VA without interstitial needle could cover HR-CTV adequately without exceeding dose to Bladder-2cc. Conventional RTA was unable to achieve target coverage for the HR-CTV >80Gy without severely overdosing OARs. Conclusion: The Ellis Interstitial Cap for the SRA offered superior dosimetric coverage as compared to the interstitialintracavitary VA. This represents the first reported use for this devise, and further investigation is warranted.« less
Radiation therapy for breast cancer: Literature review
DOE Office of Scientific and Technical Information (OSTI.GOV)
Balaji, Karunakaran, E-mail: karthik.balaji85@gmail.com; School of Advanced Sciences, VIT University, Vellore; Subramanian, Balaji
Concave shape with variable size target volume makes treatment planning for the breast/chest wall a challenge. Conventional techniques used for the breast/chest wall cancer treatment provided better sparing of organs at risk (OARs), with poor conformity and uniformity to the target volume. Advanced technologies such as intensity modulated radiotherapy (IMRT) and volumetric modulated arc therapy (VMAT) improve the target coverage at the cost of higher low dose volumes to OARs. Novel hybrid techniques present promising results in breast/chest wall irradiation in terms of target coverage as well as OARs sparing. Several published data compared these technologies for the benefit ofmore » the breast/chest wall with or without nodal volumes. The aim of this article is to review relevant data and identify the scope for further research in developing optimal treatment plan for breast/chest wall cancer treatment.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Krayenbuehl, Jerome; Hartmann, Matthias; Lomax, Anthony J.
Purpose: To perform comparative planning for intensity-modulated radiotherapy (IMRT) and proton therapy (PT) for malignant pleural mesothelioma after radical surgery. Methods and Materials: Eight patients treated with IMRT after extrapleural pleuropneumonectomy (EPP) were replanned for PT, comparing dose homogeneity, target volume coverage, and mean and maximal dose to organs at risk. Feasibility of PT was evaluated regarding the dose distribution with respect to air cavities after EPP. Results: Dose coverage and dose homogeneity of the planning target volume (PTV) were significantly better for PT than for IMRT regarding the volume covered by >95% (V95) for the high-dose PTV. The meanmore » dose to the contralateral kidney, ipsilateral kidney, contralateral lung, liver, and heart and spinal cord dose were significantly reduced with PT compared with IMRT. After EPP, air cavities were common (range, 0-850 cm{sup 3}), decreasing from 0 to 18.5 cm{sup 3}/day. In 2 patients, air cavity changes during RT decreased the generalized equivalent uniform dose (gEUD) in the case of using an a value of < - 10 to the PTV2 to <2 Gy in the presence of changing cavities for PT, and to 40 Gy for IMRT. Small changes were observed for gEUD of PTV1 because PTV1 was reached by the beams before air. Conclusion: Both PT and IMRT achieved good target coverage and dose homogeneity. Proton therapy accomplished additional dose sparing of most organs at risk compared with IMRT. Proton therapy dose distributions were more susceptible to changing air cavities, emphasizing the need for adaptive RT and replanning.« less
Machiels, Mélanie; Jin, Peng; van Gurp, Christianne H; van Hooft, Jeanin E; Alderliesten, Tanja; Hulshof, Maarten C C M
2018-03-21
To investigate the feasibility and geometric accuracy of carina-based registration for CBCT-guided setup verification in esophageal cancer IGRT, compared with current practice bony anatomy-based registration. Included were 24 esophageal cancer patients with 65 implanted fiducial markers, visible on planning CTs and follow-up CBCTs. All available CBCT scans (n = 236) were rigidly registered to the planning CT with respect to the bony anatomy and the carina. Target coverage was visually inspected and marker position variation was quantified relative to both registration approaches; the variation of systematic (Σ) and random errors (σ) was estimated. Automatic carina-based registration was feasible in 94.9% of the CBCT scans, with an adequate target coverage in 91.1% compared to 100% after bony anatomy-based registration. Overall, Σ (σ) in the LR/CC/AP direction was 2.9(2.4)/4.1(2.4)/2.2(1.8) mm using the bony anatomy registration compared to 3.3(3.0)/3.6(2.6)/3.9(3.1) mm for the carina. Mid-thoracic placed markers showed a non-significant but smaller Σ in CC and AP direction when using the carina-based registration. Compared with a bony anatomy-based registration, carina-based registration for esophageal cancer IGRT results in inadequate target coverage in 8.9% of cases. Furthermore, large Σ and σ, requiring larger anisotropic margins, were seen after carina-based registration. Only for tumors entirely confined to the mid-thoracic region the carina-based registration might be slightly favorable.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Ekici, Kemal, E-mail: drkemal06@hotmail.com; Pepele, Eda K.; Yaprak, Bahaddin
2016-01-01
Various radiotherapy planning methods for T1N0 laryngeal cancer have been proposed to decrease normal tissue toxicity. We compare helical tomotherapy (HT), linac-based intensity-modulated radiation therapy (IMRT), volumetric-modulated arc therapy (VMAT), and 3-D conformal radiotherapy (3D-CRT) techniques for T1N0 laryngeal cancer. Overall, 10 patients with T1N0 laryngeal cancer were selected and evaluated. Furthermore, 10 radiotherapy treatment plans have been created for all 10 patients, including HT, IMRT, VMAT, and 3D-CRT. IMRT, VMAT, and HT plans vs 3D-CRT plans consistently provided superior planning target volume (PTV) coverage. Similar target coverage was observed between the 3 IMRT modalities. Compared with 3D-CRT, IMRT, HT,more » and VMAT significantly reduced the mean dose to the carotid arteries. VMAT resulted in the lowest mean dose to the submandibular and thyroid glands. Compared with 3D-CRT, IMRT, HT, and VMAT significantly increased the maximum dose to the spinal cord It was observed that the 3 IMRT modalities studied showed superior target coverage with less variation between each plan in comparison with 3D-CRT. The 3D-CRT plans performed better at the D{sub max} of the spinal cord. Clinical investigation is warranted to determine if these treatment approaches would translate into a reduction in radiation therapy–induced toxicities.« less
Coverage-based constraints for IMRT optimization
NASA Astrophysics Data System (ADS)
Mescher, H.; Ulrich, S.; Bangert, M.
2017-09-01
Radiation therapy treatment planning requires an incorporation of uncertainties in order to guarantee an adequate irradiation of the tumor volumes. In current clinical practice, uncertainties are accounted for implicitly with an expansion of the target volume according to generic margin recipes. Alternatively, it is possible to account for uncertainties by explicit minimization of objectives that describe worst-case treatment scenarios, the expectation value of the treatment or the coverage probability of the target volumes during treatment planning. In this note we show that approaches relying on objectives to induce a specific coverage of the clinical target volumes are inevitably sensitive to variation of the relative weighting of the objectives. To address this issue, we introduce coverage-based constraints for intensity-modulated radiation therapy (IMRT) treatment planning. Our implementation follows the concept of coverage-optimized planning that considers explicit error scenarios to calculate and optimize patient-specific probabilities q(\\hat{d}, \\hat{v}) of covering a specific target volume fraction \\hat{v} with a certain dose \\hat{d} . Using a constraint-based reformulation of coverage-based objectives we eliminate the trade-off between coverage and competing objectives during treatment planning. In-depth convergence tests including 324 treatment plan optimizations demonstrate the reliability of coverage-based constraints for varying levels of probability, dose and volume. General clinical applicability of coverage-based constraints is demonstrated for two cases. A sensitivity analysis regarding penalty variations within this planing study based on IMRT treatment planning using (1) coverage-based constraints, (2) coverage-based objectives, (3) probabilistic optimization, (4) robust optimization and (5) conventional margins illustrates the potential benefit of coverage-based constraints that do not require tedious adjustment of target volume objectives.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Sheng, Y; Zhao, J; Wang, W
2016-06-15
Purpose: Various radiotherapy planning methods for locally recurrent nasopharynx carcinoma (R-NPC) have been proposed. The purpose of this study was to compare carbon and proton therapy for the treatment of R-NPC in terms of dose coverage for target volume and sparing for organs at risk (OARs). Methods: Six patients who were suffering from R-NPC and treated using carbon therapy were selected for this study. Treatment plans with a total dose of 57.5Gy (RBE) in 23 fractions were made using SIEMENS Syngo V11. An intensity-modulated radiotherapy optimization method was chosen for carbon plans (IMCT) while for proton plans both intensity-modulated radiotherapymore » (IMPT) and single beam optimization (proton-SBO) methods were chosen. Dose distributions, dose volume parameters, and selected dosimetric indices for target volumes and OARs were compared for all treatment plans. Results: All plans provided comparable PTV coverage. The volume covered by 95% of the prescribed dose was comparable for all three plans. The average values were 96.11%, 96.24% and 96.11% for IMCT, IMPT, and proton-SBO respectively. A significant reduction of the 80% and 50% dose volumes were observed for the IMCT plans compared to the IMPT and proton-SBO plans. Critical organs lateral to the target such as brain stem and spinal cord were better spared by IMPT than by proton-SBO, while IMCT spared those organs best. For organs in the beam path, such as parotid glands, the mean dose results were similar for all three plans. Conclusion: Carbon plans yielded better dose conformity than proton plans. They provided similar or better target coverage while significantly lowering the dose for normal tissues. Dose sparing for critical organs in IMPT plans was better than proton-SBO, however, IMPT is known to be more sensitive to range uncertainties. For proton plans it is essential to find a balance between the two optimization methods.« less
Financial incentives to encourage healthy behaviour: an analysis of U.K. media coverage.
Parke, Hannah; Ashcroft, Richard; Brown, Rebecca; Marteau, Theresa M; Seale, Clive
2013-09-01
Policies to use financial incentives to encourage healthy behaviour are controversial. Much of this controversy is played out in the mass media, both reflecting and shaping public opinion. To describe U.K. mass media coverage of incentive schemes, comparing schemes targeted at different client groups and assessing the relative prominence of the views of different interest groups. Thematic content analysis. National and local news coverage in newspapers, news media targeted at health-care providers and popular websites between January 2005 and February 2010. U.K. mass media. The study included 210 articles. Fifteen separate arguments favourable towards schemes, and 19 unfavourable, were identified. Overall, coverage was more favourable than unfavourable, although most articles reported a mix of views. Arguments about the prevalence and seriousness of the health problems targeted by incentive schemes were uncontested. Moral and ethical objections to such schemes were common, focused in particular on recipients such as drug users or the overweight who were already stereotyped as morally deficient, and these arguments were largely uncontested. Arguments about the effectiveness of schemes and their potential for benefit or harm were areas of greater contestation. Government, public health and other health-care provider interests dominated favourable coverage; opposition came from rival politicians, taxpayers' representatives, certain charities and from some journalists themselves. Those promoting incentive schemes for people who might be regarded as 'undeserving' should plan a media strategy that anticipates their public reception. © 2011 John Wiley & Sons Ltd.
Financial incentives to encourage healthy behaviour: an analysis of UK media coverage
Parke, Hannah; Ashcroft, Richard; Brown, Rebecca; Marteau, Theresa M; Seale, Clive
2011-01-01
Abstract Background Policies to use financial incentives to encourage healthy behaviour are controversial. Much of this controversy is played out in the mass media, both reflecting and shaping public opinion. Objective To describe UK mass media coverage of incentive schemes, comparing schemes targeted at different client groups and assessing the relative prominence of the views of different interest groups. Design Thematic content analysis. Subjects National and local news coverage in newspapers, news media targeted at health‐care providers and popular websites between January 2005 and February 2010. Setting UK mass media. Results The study included 210 articles. Fifteen separate arguments favourable towards schemes, and 19 unfavourable, were identified. Overall, coverage was more favourable than unfavourable, although most articles reported a mix of views. Arguments about the prevalence and seriousness of the health problems targeted by incentive schemes were uncontested. Moral and ethical objections to such schemes were common, focused in particular on recipients such as drug users or the overweight who were already stereotyped as morally deficient, and these arguments were largely uncontested. Arguments about the effectiveness of schemes and their potential for benefit or harm were areas of greater contestation. Government, public health and other health‐care provider interests dominated favourable coverage; opposition came from rival politicians, taxpayers’ representatives, certain charities and from some journalists themselves. Conclusions Those promoting incentive schemes for people who might be regarded as ‘undeserving’ should plan a media strategy that anticipates their public reception. PMID:21771227
Massa, K; Olsen, A; Sheshe, A; Ntakamulenga, R; Ndawi, B; Magnussen, P
2009-11-01
Control programmes generally use a school-based strategy of mass drug administration to reduce morbidity of schistosomiasis and soil-transmitted helminthiasis (STH) in school-aged populations. The success of school-based programmes depends on treatment coverage. The community-directed treatment (ComDT) approach has been implemented in the control of onchocerciasis and lymphatic filariasis in Africa and improves treatment coverage. This study compared the treatment coverage between the ComDT approach and the school-based treatment approach, where non-enrolled school-aged children were invited for treatment, in the control of schistosomiasis and STH among enrolled and non-enrolled school-aged children. Coverage during the first treatment round among enrolled children was similar for the two approaches (ComDT: 80.3% versus school: 82.1%, P=0.072). However, for the non-enrolled children the ComDT approach achieved a significantly higher coverage than the school-based approach (80.0 versus 59.2%, P<0.001). Similar treatment coverage levels were attained at the second treatment round. Again, equal levels of treatment coverage were found between the two approaches for the enrolled school-aged children, while the ComDT approach achieved a significantly higher coverage in the non-enrolled children. The results of this study showed that the ComDT approach can obtain significantly higher treatment coverage among the non-enrolled school-aged children compared to the school-based treatment approach for the control of schistosomiasis and STH.
Friesen, Valerie M; Aaron, Grant J; Myatt, Mark; Neufeld, Lynnette M
2017-05-01
Food fortification is a widely used approach to increase micronutrient intake in the diet. High coverage is essential for achieving impact. Data on coverage is limited in many countries, and tools to assess coverage of fortification programs have not been standardized. In 2013, the Global Alliance for Improved Nutrition developed the Fortification Assessment Coverage Toolkit (FACT) to carry out coverage assessments in both population-based (i.e., staple foods and/or condiments) and targeted (e.g., infant and young child) fortification programs. The toolkit was designed to generate evidence on program coverage and the use of fortified foods to provide timely and programmatically relevant information for decision making. This supplement presents results from FACT surveys that assessed the coverage of population-based and targeted food fortification programs across 14 countries. It then discusses the policy and program implications of the findings for the potential for impact and program improvement.
Is universal health coverage the practical expression of the right to health care?
2014-01-01
The present Millennium Development Goals are set to expire in 2015 and their next iteration is now being discussed within the international community. With regards to health, the World Health Organization proposes universal health coverage as a ‘single overarching health goal’ for the next iteration of the Millennium Development Goals. The present Millennium Development Goals have been criticised for being ‘duplicative’ or even ‘competing alternatives’ to international human rights law. The question then arises, if universal health coverage would indeed become the single overarching health goal, replacing the present health-related Millennium Development Goals, would that be more consistent with the right to health? The World Health Organization seems to have anticipated the question, as it labels universal health coverage as “by definition, a practical expression of the concern for health equity and the right to health”. Rather than waiting for the negotiations to unfold, we thought it would be useful to verify this contention, using a comparative normative analysis. We found that – to be a practical expression of the right to health – at least one element is missing in present authoritative definitions of universal health coverage: a straightforward confirmation that international assistance is essential, not optional. But universal health coverage is a ‘work in progress’. A recent proposal by the United Nations Sustainable Development Solutions Network proposed universal health coverage with a set of targets, including a target for international assistance, which would turn universal health coverage into a practical expression of the right to health care. PMID:24559232
DOE Office of Scientific and Technical Information (OSTI.GOV)
Hong, C; Ju, S; Ahn, Y
2015-06-15
Purpose: To compare normal lung-sparing capabilities of three advanced radiation therapy techniques for locally advanced non-small cell lung cancer (LA-NSCLC). Methods: Four-dimensional computed tomography (4DCT) was performed in 10 patients with stage IIIb LA-NSCLC. The internal target volume (ITV); planning target volume (PTV); and organs at risks (OARs) such as spinal cord, total normal lung, heart, and esophagus were delineated for each CT data set. Intensity-modulated radiation therapy (IMRT), Tomohelical-IMRT (TH-IMRT), and TomoDirect-IMRT (TD-IMRT) plans were generated (total prescribed dose, 66 Gy in 33 fractions to the PTV) for each patient. To reduce the normal lung dose, complete and directionalmore » block function was applied outside the normal lung far from the target for both TH-IMRT and TD-IMRT, while pseudo- OAR was set in the same region for IMRT. Dosimetric characteristics of the three plans were compared in terms of target coverage, the sparing capability for the OAR, and the normal tissue complication probability (NTCP). Beam delivery efficiency was also compared. Results: TH-IMRT and TD-IMRT provided better target coverage than IMRT plans. Lung volume receiving ≥–30 Gy, mean dose, and NTCP were significant with TH-IMRT than with IMRT (p=0.006), and volume receiving ≥20–30 Gy was lower in TD-IMRT than in IMRT (p<0.05). Compared with IMRT, TH-IMRT had better sparing effect on the spinal cord (Dmax, NTCP) and heart (V45) (p<0.05). NTCP for the spinal cord, V45 and V60 for the heart, and Dmax for the esophagus were significantly lower in TD-IMRT than in IMRT. The monitor units per fraction were clearly smaller for IMRT than for TH-IMRT and TD-IMRT (p=0.006). Conclusion: In LA-NSCLC, TH-IMRT gave superior PTV coverage and OAR sparing compared to IMRT. TH-IMRT provided better control of the lung volume receiving ≥5–30 Gy. The delivery time and monitor units were lower in TD-IMRT than in TH-IMRT.« less
TU-AB-BRB-01: Coverage Evaluation and Probabilistic Treatment Planning as a Margin Alternative
DOE Office of Scientific and Technical Information (OSTI.GOV)
Siebers, J.
The accepted clinical method to accommodate targeting uncertainties inherent in fractionated external beam radiation therapy is to utilize GTV-to-CTV and CTV-to-PTV margins during the planning process to design a PTV-conformal static dose distribution on the planning image set. Ideally, margins are selected to ensure a high (e.g. >95%) target coverage probability (CP) in spite of inherent inter- and intra-fractional positional variations, tissue motions, and initial contouring uncertainties. Robust optimization techniques, also known as probabilistic treatment planning techniques, explicitly incorporate the dosimetric consequences of targeting uncertainties by including CP evaluation into the planning optimization process along with coverage-based planning objectives. Themore » treatment planner no longer needs to use PTV and/or PRV margins; instead robust optimization utilizes probability distributions of the underlying uncertainties in conjunction with CP-evaluation for the underlying CTVs and OARs to design an optimal treated volume. This symposium will describe CP-evaluation methods as well as various robust planning techniques including use of probability-weighted dose distributions, probability-weighted objective functions, and coverage optimized planning. Methods to compute and display the effect of uncertainties on dose distributions will be presented. The use of robust planning to accommodate inter-fractional setup uncertainties, organ deformation, and contouring uncertainties will be examined as will its use to accommodate intra-fractional organ motion. Clinical examples will be used to inter-compare robust and margin-based planning, highlighting advantages of robust-plans in terms of target and normal tissue coverage. Robust-planning limitations as uncertainties approach zero and as the number of treatment fractions becomes small will be presented, as well as the factors limiting clinical implementation of robust planning. Learning Objectives: To understand robust-planning as a clinical alternative to using margin-based planning. To understand conceptual differences between uncertainty and predictable motion. To understand fundamental limitations of the PTV concept that probabilistic planning can overcome. To understand the major contributing factors to target and normal tissue coverage probability. To understand the similarities and differences of various robust planning techniques To understand the benefits and limitations of robust planning techniques.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Xu, H.
The accepted clinical method to accommodate targeting uncertainties inherent in fractionated external beam radiation therapy is to utilize GTV-to-CTV and CTV-to-PTV margins during the planning process to design a PTV-conformal static dose distribution on the planning image set. Ideally, margins are selected to ensure a high (e.g. >95%) target coverage probability (CP) in spite of inherent inter- and intra-fractional positional variations, tissue motions, and initial contouring uncertainties. Robust optimization techniques, also known as probabilistic treatment planning techniques, explicitly incorporate the dosimetric consequences of targeting uncertainties by including CP evaluation into the planning optimization process along with coverage-based planning objectives. Themore » treatment planner no longer needs to use PTV and/or PRV margins; instead robust optimization utilizes probability distributions of the underlying uncertainties in conjunction with CP-evaluation for the underlying CTVs and OARs to design an optimal treated volume. This symposium will describe CP-evaluation methods as well as various robust planning techniques including use of probability-weighted dose distributions, probability-weighted objective functions, and coverage optimized planning. Methods to compute and display the effect of uncertainties on dose distributions will be presented. The use of robust planning to accommodate inter-fractional setup uncertainties, organ deformation, and contouring uncertainties will be examined as will its use to accommodate intra-fractional organ motion. Clinical examples will be used to inter-compare robust and margin-based planning, highlighting advantages of robust-plans in terms of target and normal tissue coverage. Robust-planning limitations as uncertainties approach zero and as the number of treatment fractions becomes small will be presented, as well as the factors limiting clinical implementation of robust planning. Learning Objectives: To understand robust-planning as a clinical alternative to using margin-based planning. To understand conceptual differences between uncertainty and predictable motion. To understand fundamental limitations of the PTV concept that probabilistic planning can overcome. To understand the major contributing factors to target and normal tissue coverage probability. To understand the similarities and differences of various robust planning techniques To understand the benefits and limitations of robust planning techniques.« less
van de Schoot, Agustinus J A J; de Boer, Peter; Visser, Jorrit; Stalpers, Lukas J A; Rasch, Coen R N; Bel, Arjan
2017-05-01
Radiation therapy (RT) using a daily plan selection adaptive strategy can be applied to account for interfraction organ motion while limiting organ at risk dose. The aim of this study was to quantify the dosimetric consequences of daily plan selection compared with non-adaptive RT in cervical cancer. Ten consecutive patients who received pelvic irradiation, planning CTs (full and empty bladder), weekly post-fraction CTs and pre-fraction CBCTs were included. Non-adaptive plans were generated based on the PTV defined using the full bladder planning CT. For the adaptive strategy, multiple PTVs were created based on both planning CTs by ITVs of the primary CTVs (i.e., GTV, cervix, corpus-uterus and upper part of the vagina) and corresponding library plans were generated. Daily CBCTs were rigidly aligned to the full bladder planning CT for plan selection. For daily plan recalculation, selected CTs based on initial similarity were deformably registered to CBCTs. Differences in daily target coverage (D 98% > 95%) and in V 0.5Gy , V 1.5Gy , V 2Gy , D 50% and D 2% for rectum, bladder and bowel were assessed. Non-adaptive RT showed inadequate primary CTV coverage in 17% of the daily fractions. Plan selection compensated for anatomical changes and improved primary CTV coverage significantly (p < 0.01) to 98%. Compared with non-adaptive RT, plan selection decreased the fraction dose to rectum and bowel indicated by significant (p < 0.01) improvements for daily V 0.5Gy , V 1.5Gy , V 2Gy , D 50% and D 2% . However, daily plan selection significantly increased the bladder V 1.5Gy , V 2Gy , D 50% and D 2% . In cervical cancer RT, a non-adaptive strategy led to inadequate target coverage for individual patients. Daily plan selection corrected for day-to-day anatomical variations and resulted in adequate target coverage in all fractions. The dose to bowel and rectum was decreased significantly when applying adaptive RT.
Zöllner, Caroline; De Allegri, Manuela; Louis, Valérie R; Yé, Maurice; Sié, Ali; Tiendrebéogo, Justin; Jahn, Albrecht; Müller, Olaf
2015-03-01
Insecticide-treated mosquito nets (ITNs) are an essential tool of the Roll Back Malaria strategy. An increasing number of African countries have embarked on mass distribution campaigns of long-lasting insecticide-treated nets (LLINs) with the ultimate goal of universal coverage. Such a national campaign with the goal of one ITN for every two people has been conducted in Burkina Faso in 2010. Our aim was to assess the coverage and equity effect of the universal distribution campaign of LLINs in Burkina Faso and to identify determinants of ITN ownership across households after the campaign. We evaluated its effects through comparison of data from two household surveys conducted in early 2010 (before the campaign) and early 2011 (after the campaign) on a representative rural district in north-western Burkina Faso. Data were collected on household characteristics (including socio-economic status) and ITN ownership. We used concentration curves and indices to compare ITN coverage indicators before and after the campaign and multilevel multivariate logistic regression to estimate factors associated with achievement of the universal coverage target in 2011. The survey included 1106 households in 2010 and 1094 in 2011. We found that the proportion of households with at least one ITN increased from 59% before the campaign to 99% afterwards, whereas the concentration index dropped from 0.087 (standard error (SE): 0.014) to 0.002 (SE: 0.002). Fifty-two per cent of households reached the target of one ITN for every two people per household, with the relevant concentration index at -0.031 (SE: 0.016). Eighty-six per cent of households owned at least one ITN for every three people. The main characteristics significantly associated with the targeted intra-household coverage were family size and distance to the health centre but not socio-economic status. In conclusion, despite not having fully met its target, the national LLIN campaign achieved a high level of coverage and fostered equity. Published by Oxford University Press in association with The London School of Hygiene and Tropical Medicine © The Author 2014; all rights reserved.
Influenza immunization among Canadian health care personnel: a cross-sectional study
Buchan, Sarah A.; Kwong, Jeffrey C.
2016-01-01
Background: Influenza immunization coverage among Canadian health care personnel remains below national targets. Targeting this group is of particular importance given their elevated risk of influenza infection, role in transmission and influence on patients' immunization status. We examined influenza immunization coverage in health care personnel in Canada, reasons for not being immunized and the impact of "vaccinate-or-mask" influenza prevention policies. Methods: In this national cross-sectional study, we pooled data from the 2007 to 2014 cycles of the Canadian Community Health Survey and restricted it to respondents who reported a health care occupation. Using bootstrapped survey weights, we examined immunization coverage by occupation and by presence of vaccinate-or-mask policies, and reasons for not being immunized. We used modified Poisson regression to estimate the prevalence ratio (PR) of influenza immunization for health care occupations compared with the general working population. Results: For all survey cycles combined, 50% of 18 446 health care personnel reported receiving seasonal influenza immunization during the previous 12 months, although this varied by occupation type (range 4%-72%). Compared with the general working population, family physicians and general practitioners were most likely to be immunized (PR 3.15, 95% confidence interval [CI] 2.76-3.59), whereas chiropractors, midwives and practitioners of natural healing were least likely (PR 0.17, 95% CI 0.10-0.30). Among those who were not immunized, the most frequently cited reason was the belief that influenza immunization is unnecessary. Introduction of vaccinate-or-mask policies was associated with increased influenza immunization among health care personnel. Interpretation: Health care personnel are more likely to be immunized against influenza than the general working population, but coverage remains suboptimal overall, and we observed wide variation by occupation type. More efforts are needed to target specific health care occupations with low immunization coverage. PMID:27730112
Target Coverage in Wireless Sensor Networks with Probabilistic Sensors
Shan, Anxing; Xu, Xianghua; Cheng, Zongmao
2016-01-01
Sensing coverage is a fundamental problem in wireless sensor networks (WSNs), which has attracted considerable attention. Conventional research on this topic focuses on the 0/1 coverage model, which is only a coarse approximation to the practical sensing model. In this paper, we study the target coverage problem, where the objective is to find the least number of sensor nodes in randomly-deployed WSNs based on the probabilistic sensing model. We analyze the joint detection probability of target with multiple sensors. Based on the theoretical analysis of the detection probability, we formulate the minimum ϵ-detection coverage problem. We prove that the minimum ϵ-detection coverage problem is NP-hard and present an approximation algorithm called the Probabilistic Sensor Coverage Algorithm (PSCA) with provable approximation ratios. To evaluate our design, we analyze the performance of PSCA theoretically and also perform extensive simulations to demonstrate the effectiveness of our proposed algorithm. PMID:27618902
Seo, Jeongmin; Lim, Juwon
2018-05-05
Influenza is a major cause of morbidity and mortality worldwide. Annual vaccination is effective in its prevention and is recommended especially in susceptible populations such as the elderly over 65 years, children younger than 5, pregnant women, and people with chronic diseases. Overall, South Korea has a high vaccination rate owing to its National Immunization Program, although the method and extent of its coverage varies among the target subgroups. The aim of this study is to assess the trend of influenza vaccination coverage between 2005 and 2014 in South Korea to address the influence of sociodemographic and disease factors on vaccination behavior. Also, we aim to compare the vaccination coverage of target subgroups and evaluate the effect of relevant policies to provide suggestions for their improvement. A total of 61,036 respondents from the Korea National Health and Nutrition Examination Surveys III to VI were included. The total influenza vaccination coverage increased from 38.0% in 2005 to 44.1% in 2014. Vaccination coverage was higher among the elderly aged ≥65 years (range, 70.0-79.8%; p-for-trend <0.001) and children under 5 (range, 64.6-78.9%; p-for-trend < 0.001) than among pregnant women (range, 9.4-37.8%; p-for-trend = 0.122) and people with chronic diseases (range, 29.6-42.6%; p-for-trend = 0.068) from 2005 to 2014. High vaccination coverage was associated with female gender, rural residence, low education level, high income, and increasing number of chronic diseases. But the effect of high income on high vaccination coverage was absent in the elderly aged ≥65 years and children under 5. Influenza vaccination rates have steadily increased from 2005 to 2014 in South Korea. Disparities between target groups correspond to their financial coverage under the National Immunization Program, and financial aids remove the influence of high income on higher vaccination rates. Future vaccination policies should focus on pregnant women and people with chronic diseases. Copyright © 2018 Elsevier Ltd. All rights reserved.
Zha, Haihong; Cai, Yuping; Yin, Yandong; Wang, Zhuozhong; Li, Kang; Zhu, Zheng-Jiang
2018-03-20
The complexity of metabolome presents a great analytical challenge for quantitative metabolite profiling, and restricts the application of metabolomics in biomarker discovery. Targeted metabolomics using multiple-reaction monitoring (MRM) technique has excellent capability for quantitative analysis, but suffers from the limited metabolite coverage. To address this challenge, we developed a new strategy, namely, SWATHtoMRM, which utilizes the broad coverage of SWATH-MS technology to develop high-coverage targeted metabolomics method. Specifically, SWATH-MS technique was first utilized to untargeted profile one pooled biological sample and to acquire the MS 2 spectra for all metabolites. Then, SWATHtoMRM was used to extract the large-scale MRM transitions for targeted analysis with coverage as high as 1000-2000 metabolites. Then, we demonstrated the advantages of SWATHtoMRM method in quantitative analysis such as coverage, reproducibility, sensitivity, and dynamic range. Finally, we applied our SWATHtoMRM approach to discover potential metabolite biomarkers for colorectal cancer (CRC) diagnosis. A high-coverage targeted metabolomics method with 1303 metabolites in one injection was developed to profile colorectal cancer tissues from CRC patients. A total of 20 potential metabolite biomarkers were discovered and validated for CRC diagnosis. In plasma samples from CRC patients, 17 out of 20 potential biomarkers were further validated to be associated with tumor resection, which may have a great potential in assessing the prognosis of CRC patients after tumor resection. Together, the SWATHtoMRM strategy provides a new way to develop high-coverage targeted metabolomics method, and facilitates the application of targeted metabolomics in disease biomarker discovery. The SWATHtoMRM program is freely available on the Internet ( http://www.zhulab.cn/software.php ).
Optimization of Self-Directed Target Coverage in Wireless Multimedia Sensor Network
Yang, Yang; Wang, Yufei; Pi, Dechang; Wang, Ruchuan
2014-01-01
Video and image sensors in wireless multimedia sensor networks (WMSNs) have directed view and limited sensing angle. So the methods to solve target coverage problem for traditional sensor networks, which use circle sensing model, are not suitable for WMSNs. Based on the FoV (field of view) sensing model and FoV disk model proposed, how expected multimedia sensor covers the target is defined by the deflection angle between target and the sensor's current orientation and the distance between target and the sensor. Then target coverage optimization algorithms based on expected coverage value are presented for single-sensor single-target, multisensor single-target, and single-sensor multitargets problems distinguishingly. Selecting the orientation that sensor rotated to cover every target falling in the FoV disk of that sensor for candidate orientations and using genetic algorithm to multisensor multitargets problem, which has NP-complete complexity, then result in the approximated minimum subset of sensors which covers all the targets in networks. Simulation results show the algorithm's performance and the effect of number of targets on the resulting subset. PMID:25136667
Newspaper coverage of mental illness in England 2008-2011.
Thornicroft, Amalia; Goulden, Robert; Shefer, Guy; Rhydderch, Danielle; Rose, Diana; Williams, Paul; Thornicroft, Graham; Henderson, Claire
2013-04-01
Better newspaper coverage of mental health-related issues is a target for the Time to Change (TTC) anti-stigma programme in England, whose population impact may be influenced by how far concurrent media coverage perpetuates stigma and discrimination. To compare English newspaper coverage of mental health-related topics each year of the TTC social marketing campaign (2009-2011) with baseline coverage in 2008. Content analysis was performed on articles in 27 local and national newspapers on two randomly chosen days each month. There was a significant increase in the proportion of anti-stigmatising articles between 2008 and 2011. There was no concomitant proportional decrease in stigmatising articles, and the contribution of mixed or neutral elements decreased. These findings provide promising results on improvements in press reporting of mental illness during the TTC programme in 2009-2011, and a basis for guidance to newspaper journalists and editors on reporting mental illness.
SU-E-J-159: Analysis of Total Imaging Uncertainty in Respiratory-Gated Radiotherapy
DOE Office of Scientific and Technical Information (OSTI.GOV)
Suzuki, J; Okuda, T; Sakaino, S
Purpose: In respiratory-gated radiotherapy, the gating phase during treatment delivery needs to coincide with the corresponding phase determined during the treatment plan. However, because radiotherapy is performed based on the image obtained for the treatment plan, the time delay, motion artifact, volume effect, and resolution in the images are uncertain. Thus, imaging uncertainty is the most basic factor that affects the localization accuracy. Therefore, these uncertainties should be analyzed. This study aims to analyze the total imaging uncertainty in respiratory-gated radiotherapy. Methods: Two factors of imaging uncertainties related to respiratory-gated radiotherapy were analyzed. First, CT image was used to determinemore » the target volume and 4D treatment planning for the Varian Realtime Position Management (RPM) system. Second, an X-ray image was acquired for image-guided radiotherapy (IGRT) for the BrainLAB ExacTrac system. These factors were measured using a respiratory gating phantom. The conditions applied during phantom operation were as follows: respiratory wave form, sine curve; respiratory cycle, 4 s; phantom target motion amplitude, 10, 20, and 29 mm (which is maximum phantom longitudinal motion). The target and cylindrical marker implanted in the phantom coverage of the CT images was measured and compared with the theoretically calculated coverage from the phantom motion. The theoretical position of the cylindrical marker implanted in the phantom was compared with that acquired from the X-ray image. The total imaging uncertainty was analyzed from these two factors. Results: In the CT image, the uncertainty between the target and cylindrical marker’s actual coverage and the coverage of CT images was 1.19 mm and 2.50mm, respectively. In the Xray image, the uncertainty was 0.39 mm. The total imaging uncertainty from the two factors was 1.62mm. Conclusion: The total imaging uncertainty in respiratory-gated radiotherapy was clinically acceptable. However, an internal margin should be added to account for the total imaging uncertainty.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Pham, Daniel, E-mail: Daniel.Pham@petermac.org; Kron, Tomas; Foroudi, Farshad
2013-10-01
Stereotactic ablative body radiotherapy (SABR) for primary renal cell carcinoma (RCC) targets requires motion management strategies to verify dose delivery. This case study highlights the effect of a change in patient breathing amplitude on the dosimetry to organs at risk and target structures. A 73-year-old male patient was planned for receiving 26 Gy of radiation in 1 fraction of SABR for a left primary RCC. The patient was simulated with four-dimensional computed tomography (4DCT) and the tumor internal target volume (ITV) was delineated using the 4DCT maximum intensity projection. However, the initially planned treatment was abandoned at the radiation oncologist'smore » discretion after pretreatment cone-beam CT (CBCT) motion verification identified a greater than 50% reduction in superior to inferior diaphragm motion as compared with the planning 4DCT. This patient was resimulated with respiratory coaching instructions. To assess the effect of the change in breathing on the dosimetry to the target, each plan was recalculated on the data set representing the change in breathing condition. A change from smaller to larger breathing showed a 46% loss in planning target volume (PTV) coverage, whereas a change from larger breathing to smaller breathing resulted in an 8% decrease in PTV coverage. ITV coverage was similarly reduced by 8% in both scenarios. This case study highlights the importance of tools to verify breathing motion prior to treatment delivery. 4D image guided radiation therapy verification strategies should focus on not only verifying ITV margin coverage but also the effect on the surrounding organs at risk.« less
Strategies for Coordination of a Serosurvey in Parallel with an Immunization Coverage Survey
Travassos, Mark A.; Beyene, Berhane; Adam, Zenaw; Campbell, James D.; Mulholland, Nigisti; Diarra, Seydou S.; Kassa, Tassew; Oot, Lisa; Sequeira, Jenny; Reymann, Mardi; Blackwelder, William C.; Pasetti, Marcela F.; Sow, Samba O.; Steinglass, Robert; Kebede, Amha; Levine, Myron M.
2015-01-01
A community-based immunization coverage survey is the standard way to estimate effective vaccination delivery to a target population in a region. Accompanying serosurveys can provide objective measures of protective immunity against vaccine-preventable diseases but pose considerable challenges with respect to specimen collection and preservation and community compliance. We performed serosurveys coupled to immunization coverage surveys in three administrative districts (woredas) in rural Ethiopia. Critical to the success of this effort were serosurvey equipment and supplies, team composition, and tight coordination with the coverage survey. Application of these techniques to future studies may foster more widespread use of serosurveys to derive more objective assessments of vaccine-derived seroprotection and monitor and compare the performance of immunization services in different districts of a country. PMID:26055737
Electron intensity modulation for mixed-beam radiation therapy with an x-ray multi-leaf collimator
NASA Astrophysics Data System (ADS)
Weinberg, Rebecca
The current standard treatment for head and neck cancer at our institution uses intensity-modulated x-ray therapy (IMRT), which improves target coverage and sparing of critical structures by delivering complex fluence patterns from a variety of beam directions to conform dose distributions to the shape of the target volume. The standard treatment for breast patients is field-in-field forward-planned IMRT, with initial tangential fields and additional reduced-weight tangents with blocking to minimize hot spots. For these treatment sites, the addition of electrons has the potential of improving target coverage and sparing of critical structures due to rapid dose falloff with depth and reduced exit dose. In this work, the use of mixed-beam therapy (MBT), i.e., combined intensity-modulated electron and x-ray beams using the x-ray multi-leaf collimator (MLC), was explored. The hypothesis of this study was that addition of intensity-modulated electron beams to existing clinical IMRT plans would produce MBT plans that were superior to the original IMRT plans for at least 50% of selected head and neck and 50% of breast cases. Dose calculations for electron beams collimated by the MLC were performed with Monte Carlo methods. An automation system was created to facilitate communication between the dose calculation engine and the treatment planning system. Energy and intensity modulation of the electron beams was accomplished by dividing the electron beams into 2x2-cm2 beamlets, which were then beam-weight optimized along with intensity-modulated x-ray beams. Treatment plans were optimized to obtain equivalent target dose coverage, and then compared with the original treatment plans. MBT treatment plans were evaluated by participating physicians with respect to target coverage, normal structure dose, and overall plan quality in comparison with original clinical plans. The physician evaluations did not support the hypothesis for either site, with MBT selected as superior in 1 out of the 15 head and neck cases (p=1) and 6 out of 18 breast cases (p=0.95). While MBT was not shown to be superior to IMRT, reductions were observed in doses to critical structures distal to the target along the electron beam direction and to non-target tissues, at the expense of target coverage and dose homogeneity.
Role of step size and max dwell time in anatomy based inverse optimization for prostate implants
Manikandan, Arjunan; Sarkar, Biplab; Rajendran, Vivek Thirupathur; King, Paul R.; Sresty, N.V. Madhusudhana; Holla, Ragavendra; Kotur, Sachin; Nadendla, Sujatha
2013-01-01
In high dose rate (HDR) brachytherapy, the source dwell times and dwell positions are vital parameters in achieving a desirable implant dose distribution. Inverse treatment planning requires an optimal choice of these parameters to achieve the desired target coverage with the lowest achievable dose to the organs at risk (OAR). This study was designed to evaluate the optimum source step size and maximum source dwell time for prostate brachytherapy implants using an Ir-192 source. In total, one hundred inverse treatment plans were generated for the four patients included in this study. Twenty-five treatment plans were created for each patient by varying the step size and maximum source dwell time during anatomy-based, inverse-planned optimization. Other relevant treatment planning parameters were kept constant, including the dose constraints and source dwell positions. Each plan was evaluated for target coverage, urethral and rectal dose sparing, treatment time, relative target dose homogeneity, and nonuniformity ratio. The plans with 0.5 cm step size were seen to have clinically acceptable tumor coverage, minimal normal structure doses, and minimum treatment time as compared with the other step sizes. The target coverage for this step size is 87% of the prescription dose, while the urethral and maximum rectal doses were 107.3 and 68.7%, respectively. No appreciable difference in plan quality was observed with variation in maximum source dwell time. The step size plays a significant role in plan optimization for prostate implants. Our study supports use of a 0.5 cm step size for prostate implants. PMID:24049323
Hill, Holly A; Elam-Evans, Laurie D; Yankey, David; Singleton, James A; Kolasa, Maureen
2015-08-28
The reduction in morbidity and mortality associated with vaccine-preventable diseases in the United States has been described as one of the 10 greatest public health achievements of the first decade of the 21st century. A recent analysis concluded that routine childhood vaccination will prevent 322 million cases of disease and about 732,000 early deaths among children born during 1994-2013, for a net societal cost savings of $1.38 trillion. The National Immunization Survey (NIS) has monitored vaccination coverage among U.S. children aged 19-35 months since 1994. This report presents national, regional, state, and selected local area vaccination coverage estimates for children born from January 2011 through May 2013, based on data from the 2014 NIS. For most vaccinations, there was no significant change in coverage between 2013 and 2014. The exception was hepatitis A vaccine (HepA), for which increases were observed in coverage with both ≥1 and ≥2 doses. As in previous years, <1% of children received no vaccinations. National coverage estimates indicate that the Healthy People 2020 target* of 90% was met for ≥3 doses of poliovirus vaccine (93.3%), ≥1 dose of measles, mumps, and rubella vaccine (MMR) (91.5%), ≥3 doses of hepatitis B vaccine (HepB) (91.6%), and ≥1 dose of varicella vaccine (91.0%). Coverage was below target for ≥4 doses of diphtheria, tetanus, and acellular pertussis vaccine (DTaP), the full series of Haemophilus influenzae type b (Hib) vaccine, hepatitis B (HepB) birth dose,† ≥4 doses pneumococcal conjugate vaccine (PCV), ≥2 doses of HepA, the full series of rotavirus vaccine, and the combined vaccine series.§ Examination of coverage by child's race/ethnicity revealed lower estimated coverage among non-Hispanic black children compared with non-Hispanic white children for several vaccinations, including DTaP, the full series of Hib, PCV, rotavirus vaccine, and the combined series. Children from households classified as below the federal poverty level had lower estimated coverage for almost all of the vaccinations assessed, compared with children living at or above the poverty level. Significant variation in coverage by state¶ was observed for several vaccinations, including HepB birth dose, HepA, and rotavirus. High vaccination coverage must be maintained across geographic and sociodemographic groups if progress in reducing the impact of vaccine-preventable diseases is to be sustained.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Liu, Wei, E-mail: Liu.Wei@mayo.edu; Schild, Steven E.; Chang, Joe Y.
Purpose: The purpose of this study was to compare the impact of uncertainties and interplay on 3-dimensional (3D) and 4D robustly optimized intensity modulated proton therapy (IMPT) plans for lung cancer in an exploratory methodology study. Methods and Materials: IMPT plans were created for 11 nonrandomly selected non-small cell lung cancer (NSCLC) cases: 3D robustly optimized plans on average CTs with internal gross tumor volume density overridden to irradiate internal target volume, and 4D robustly optimized plans on 4D computed tomography (CT) to irradiate clinical target volume (CTV). Regular fractionation (66 Gy [relative biological effectiveness; RBE] in 33 fractions) was considered.more » In 4D optimization, the CTV of individual phases received nonuniform doses to achieve a uniform cumulative dose. The root-mean-square dose-volume histograms (RVH) measured the sensitivity of the dose to uncertainties, and the areas under the RVH curve (AUCs) were used to evaluate plan robustness. Dose evaluation software modeled time-dependent spot delivery to incorporate interplay effect with randomized starting phases of each field per fraction. Dose-volume histogram (DVH) indices comparing CTV coverage, homogeneity, and normal tissue sparing were evaluated using Wilcoxon signed rank test. Results: 4D robust optimization plans led to smaller AUC for CTV (14.26 vs 18.61, respectively; P=.001), better CTV coverage (Gy [RBE]) (D{sub 95%} CTV: 60.6 vs 55.2, respectively; P=.001), and better CTV homogeneity (D{sub 5%}-D{sub 95%} CTV: 10.3 vs 17.7, resspectively; P=.002) in the face of uncertainties. With interplay effect considered, 4D robust optimization produced plans with better target coverage (D{sub 95%} CTV: 64.5 vs 63.8, respectively; P=.0068), comparable target homogeneity, and comparable normal tissue protection. The benefits from 4D robust optimization were most obvious for the 2 typical stage III lung cancer patients. Conclusions: Our exploratory methodology study showed that, compared to 3D robust optimization, 4D robust optimization produced significantly more robust and interplay-effect-resistant plans for targets with comparable dose distributions for normal tissues. A further study with a larger and more realistic patient population is warranted to generalize the conclusions.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Wang, Jiahao, E-mail: mashenglin@medmail.com.cn; Li, Xiadong; Deng, Qinghua
2015-10-01
The purposes of this article were to compare the biophysical dosimetry for postmastectomy left-sided breast cancer using 4 different radiotherapy (RT) techniques. In total, 30 patients with left-sided breast cancer were randomly selected for this treatment planning study. They were planned using 4 RT techniques, including the following: (1) 3-dimensional conventional tangential fields (TFs), (2) tangential intensity-modulated therapy (T-IMRT), (3) 4 fields IMRT (4F-IMRT), and (4) single arc volumetric-modulated arc therapy (S-VMAT). The planning target volume (PTV) dose was prescribed 50 Gy, the comparison of target dose distribution, conformity index, homogeneity index, dose to organs at risk (OARs), tumor controlmore » probability (TCP), normal tissue complication probability (NTCP), and number of monitor units (MUs) between 4 plans were investigated for their biophysical dosimetric difference. The target conformity and homogeneity of S-VMAT were better than the other 3 kinds of plans, but increased the volume of OARs receiving low dose (V{sub 5}). TCP of PTV and NTCP of the left lung showed no statistically significant difference in 4 plans. 4F-IMRT plan was superior in terms of target coverage and protection of OARs and demonstrated significant advantages in decreasing the NTCP of heart by 0.07, 0.03, and 0.05 compared with TFs, T-IMRT, and S-VMAT plan. Compared with other 3 plans, TFs reduced the average number of MUs. Of the 4 techniques studied, this analysis supports 4F-IMRT as the most appropriate balance of target coverage and normal tissue sparing.« less
Dosimetric comparison of four different external beams for breast irradiation
NASA Astrophysics Data System (ADS)
Lee, Yoon Hee; Chung, Weon Kuu; Kim, Dong Wook; Kwon, Oh Young
2017-02-01
An intensity-modulated radiation-therapy (IMRT)-based technique, blocked single iso-centric IMRT (IMRT), is compared to multi-center IMRT (MIRT) and other conventional techniques such as three dimensional conformal radiation therapy (3D-CRT) and volumetric modulated arc therapy (VMAT) for the treatment of breast cancer patients. Four different plans were devised and compared for 15 breast cancer patients, all of whom had early stage disease and had undergone breast conserving surgery. A total dose of 50.4 Gy in 28 fractions was prescribed as the planning target volume in all treatment plans. The doses to the ipsilateral lung, heart, and opposite breast were compared using a dose-volume histogram. The conformity index (CI), homogeneity index (HI), and coverage index (CoVI) were evaluated and compared among the four treatment techniques. The lifetime attributable risk (LAR) associated with each of the four techniques from age at exposure of 30 to 100 years was measured for the organs at risk. We found that MIRT had a better CoVI (1.02 ± 0.13 and 1.01 ± 0.04, respectively) and IMRT had a better CI (0.88 ± 0.04, and 0.87 ± 0.02, respectively) compared to the other three modalities. All four techniques had similar HIs. Moreover, we found that IMRT and MIRT were less likely to cause radiation induced-pneumonitis, 3D-CRT had the lowest LAR, IMRT and MIRT had similar LARs and VMAT had the highest LAR. In study we found that compared to the VMAT, MIRT and IMRT provided adequate the planning target volume (PTV) coverage and reduced the risk of secondary cancers in most of the organs at risk (OARs), while 3D-CRT had the lowest secondary-cancer risks. Therefore, 3D-CRT is still a reasonable choice for whole breast RT except for patients with complex PTV shapes, in which cases IMRT and MIRT may provide better target coverage.
Yock, Adam D; Kim, Gwe-Ya
2017-09-01
To present the k-means clustering algorithm as a tool to address treatment planning considerations characteristic of stereotactic radiosurgery using a single isocenter for multiple targets. For 30 patients treated with stereotactic radiosurgery for multiple brain metastases, the geometric centroids and radii of each met were determined from the treatment planning system. In-house software used this as well as weighted and unweighted versions of the k-means clustering algorithm to group the targets to be treated with a single isocenter, and to position each isocenter. The algorithm results were evaluated using within-cluster sum of squares as well as a minimum target coverage metric that considered the effect of target size. Both versions of the algorithm were applied to an example patient to demonstrate the prospective determination of the appropriate number and location of isocenters. Both weighted and unweighted versions of the k-means algorithm were applied successfully to determine the number and position of isocenters. Comparing the two, both the within-cluster sum of squares metric and the minimum target coverage metric resulting from the unweighted version were less than those from the weighted version. The average magnitudes of the differences were small (-0.2 cm 2 and 0.1% for the within cluster sum of squares and minimum target coverage, respectively) but statistically significant (Wilcoxon signed-rank test, P < 0.01). The differences between the versions of the k-means clustering algorithm represented an advantage of the unweighted version for the within-cluster sum of squares metric, and an advantage of the weighted version for the minimum target coverage metric. While additional treatment planning considerations have a large influence on the final treatment plan quality, both versions of the k-means algorithm provide automatic, consistent, quantitative, and objective solutions to the tasks associated with SRS treatment planning using a single isocenter for multiple targets. © 2017 The Authors. Journal of Applied Clinical Medical Physics published by Wiley Periodicals, Inc. on behalf of American Association of Physicists in Medicine.
Madan, Renu; Pathy, Sushmita; Subramani, Vellaiyan; Sharma, Seema; Mohanti, Bidhu Kalyan; Chander, Subhash; Thulkar, Sanjay; Kumar, Lalit; Dadhwal, Vatsla
2014-01-01
Dosimetric comparison of two dimensional (2D) radiography and three-dimensional computed tomography (3D-CT) based dose distributions with high-dose-rate (HDR) intracavitry radiotherapy (ICRT) for carcinoma cervix, in terms of target coverage and doses to bladder and rectum. Sixty four sessions of HDR ICRT were performed in 22 patients. External beam radiotherapy to pelvis at a dose of 50 Gray in 27 fractions followed by HDR ICRT, 21 Grays to point A in 3 sessions, one week apart was planned . All patients underwent 2D-orthogonal and 3D-CT simulation for each session. Treatment plans were generated using 2D-orthogonal images and dose prescription was made at point A. 3D plans were generated using 3D-CT images after delineating target volume and organs at risk. Comparative evaluation of 2D and 3D treatment planning was made for each session in terms of target coverage (dose received by 90%, 95% and 100% of the target volume: D90, D95 and D100 respectively) and doses to bladder and rectum: ICRU-38 bladder and rectum point dose in 2D planning and dose to 0.1cc, 1cc, 2cc, 5cc, and 10cc of bladder and rectum in 3D planning. Mean doses received by 100% and 90% of the target volume were 4.24 ± 0.63 and 4.9 ± 0.56 Gy respectively. Doses received by 0.1cc, 1cc and 2cc volume of bladder were 2.88 ± 0.72, 2.5 ± 0.65 and 2.2 ± 0.57 times more than the ICRU bladder reference point. Similarly, doses received by 0.1cc, 1cc and 2cc of rectum were 1.80 ± 0.5, 1.48 ± 0.41 and 1.35 ± 0.37 times higher than ICRU rectal reference point. Dosimetric comparative evaluation of 2D and 3D CT based treatment planning for the same brachytherapy session demonstrates underestimation of OAR doses and overestimation of target coverage in 2D treatment planning.
4D Optimization of Scanned Ion Beam Tracking Therapy for Moving Tumors
Eley, John Gordon; Newhauser, Wayne David; Lüchtenborg, Robert; Graeff, Christian; Bert, Christoph
2014-01-01
Motion mitigation strategies are needed to fully realize the theoretical advantages of scanned ion beam therapy for patients with moving tumors. The purpose of this study was to determine whether a new four-dimensional (4D) optimization approach for scanned-ion-beam tracking could reduce dose to avoidance volumes near a moving target while maintaining target dose coverage, compared to an existing 3D-optimized beam tracking approach. We tested these approaches computationally using a simple 4D geometrical phantom and a complex anatomic phantom, that is, a 4D computed tomogram of the thorax of a lung cancer patient. We also validated our findings using measurements of carbon-ion beams with a motorized film phantom. Relative to 3D-optimized beam tracking, 4D-optimized beam tracking reduced the maximum predicted dose to avoidance volumes by 53% in the simple phantom and by 13% in the thorax phantom. 4D-optimized beam tracking provided similar target dose homogeneity in the simple phantom (standard deviation of target dose was 0.4% versus 0.3%) and dramatically superior homogeneity in the thorax phantom (D5-D95 was 1.9% versus 38.7%). Measurements demonstrated that delivery of 4D-optimized beam tracking was technically feasible and confirmed a 42% decrease in maximum film exposure in the avoidance region compared with 3D-optimized beam tracking. In conclusion, we found that 4D-optimized beam tracking can reduce the maximum dose to avoidance volumes near a moving target while maintaining target dose coverage, compared with 3D-optimized beam tracking. PMID:24889215
4D optimization of scanned ion beam tracking therapy for moving tumors
NASA Astrophysics Data System (ADS)
Eley, John Gordon; Newhauser, Wayne David; Lüchtenborg, Robert; Graeff, Christian; Bert, Christoph
2014-07-01
Motion mitigation strategies are needed to fully realize the theoretical advantages of scanned ion beam therapy for patients with moving tumors. The purpose of this study was to determine whether a new four-dimensional (4D) optimization approach for scanned-ion-beam tracking could reduce dose to avoidance volumes near a moving target while maintaining target dose coverage, compared to an existing 3D-optimized beam tracking approach. We tested these approaches computationally using a simple 4D geometrical phantom and a complex anatomic phantom, that is, a 4D computed tomogram of the thorax of a lung cancer patient. We also validated our findings using measurements of carbon-ion beams with a motorized film phantom. Relative to 3D-optimized beam tracking, 4D-optimized beam tracking reduced the maximum predicted dose to avoidance volumes by 53% in the simple phantom and by 13% in the thorax phantom. 4D-optimized beam tracking provided similar target dose homogeneity in the simple phantom (standard deviation of target dose was 0.4% versus 0.3%) and dramatically superior homogeneity in the thorax phantom (D5-D95 was 1.9% versus 38.7%). Measurements demonstrated that delivery of 4D-optimized beam tracking was technically feasible and confirmed a 42% decrease in maximum film exposure in the avoidance region compared with 3D-optimized beam tracking. In conclusion, we found that 4D-optimized beam tracking can reduce the maximum dose to avoidance volumes near a moving target while maintaining target dose coverage, compared with 3D-optimized beam tracking.
CBCT-guided evolutive library for cervical adaptive IMRT.
Rigaud, Bastien; Simon, Antoine; Gobeli, Maxime; Lafond, Caroline; Leseur, Julie; Barateau, Anais; Jaksic, Nicolas; Castelli, Joël; Williaume, Danièle; Haigron, Pascal; De Crevoisier, Renaud
2018-04-01
In the context of adaptive radiation therapy (ART) for locally advanced cervical carcinoma (LACC), this study proposed an original cone-beam computed tomography (CBCT)-guided "Evolutive library" and evaluated it against four other known radiotherapy (RT) strategies. For 20 patients who underwent intensity-modulated radiation therapy (IMRT) for LACC, three planning CTs [with empty (EB), intermediate (IB), and full (FB) bladder volumes], a CT scan at 20 Gy and bi-weekly CBCTs for 5 weeks were performed. Five RT strategies were simulated for each patient: "Standard RT" was based on one IB planning CT; "internal target volume (ITV)-based RT" was an ITV built from the three planning CTs; "RT with one mid-treatment replanning (MidTtReplan)" corresponded to the standard RT with a replanning at 20 Gy; "Pretreatment library ART" using a planning library based on the three planning CTs; and the "Evolutive library ART", which was the "Pretreatment library ART" strategy enriched by including some CBCT anatomies into the library when the daily clinical target volume (CTV) shape differed from the ones in the library. Two planning target volume (PTV) margins of 7 and 10 mm were evaluated. All the strategies were geometrically compared in terms of the percentage of coverage by the PTV, for the CTV and the organs at risk (OAR) delineated on the CBCT. Inadequate coverage of the CTV and OARs by the PTV was also assessed using deformable image registration. The cumulated dose distributions of each strategy were likewise estimated and compared for one patient. The "Evolutive library ART" strategy involved a number of added CBCTs: 0 for 55%; 1 for 30%; 2 for 5%; and 3 for 10% of patients. Compared with the other four, this strategy provided the highest CTV geometric coverage by the PTV, with a mean (min-max) coverage of 98.5% (96.4-100) for 10 mm margins and 96.2% (93.0-99.7) for 7 mm margins (P < 0.05). Moreover, this strategy significantly decreased the geometric coverage of the bowel. CTV undercoverage by PTV occurred in the anterior and superior uterine regions for all strategies. The dosimetric analysis at 7 mm similarly demonstrated that the "Evolutive library ART" increased the V 42.75Gy of the CTV by 27%, 20%, 13%, and 28% compared with "Standard RT", "ITV-based RT", "MidTtReplan", and "Pretreatment library ART", respectively. The dose to the bowel was also decreased by the "Evolutive library ART" compared with that by the other strategies. The "Evolutive library ART" is a personalized ART strategy that comprises a pretreatment planning library of three CT scans, enriched for half of the patients by one to three per-treatment CBCTs. This original strategy increased both the CTV coverage and bowel sparing compared with all the other tested strategies and enables us to consider a PTV margin reduction. © 2018 American Association of Physicists in Medicine.
A novel probabilistic approach to generating PTV with partial voxel contributions
NASA Astrophysics Data System (ADS)
Tsang, H. S.; Kamerling, C. P.; Ziegenhein, P.; Nill, S.; Oelfke, U.
2017-06-01
Radiotherapy treatment planning for use with high-energy photon beams currently employs a binary approach in defining the planning target volume (PTV). We propose a margin concept that takes the beam directions into account, generating beam-dependent PTVs (bdPTVs) on a beam-by-beam basis. The resulting degree of overlaps between the bdPTVs are used within the optimisation process; the optimiser effectively considers the same voxel to be both target and organ at risk (OAR) with fractional contributions. We investigate the impact of this novel approach when applied to prostate radiotherapy treatments, and compare treatment plans generated using beam dependent margins to conventional margins. Five prostate patients were used in this planning study, and plans using beam dependent margins improved the sparing of high doses to target-surrounding OARs, though a trade-off in delivering additional low dose to the OARs can be observed. Plans using beam dependent margins are observed to have a slightly reduced target coverage. Nevertheless, all plans are able to satisfy 90% population coverage with the target receiving at least 95% of the prescribed dose to D98% .
DOE Office of Scientific and Technical Information (OSTI.GOV)
Yu, Yao; Chen, Josephine; Leary, Celeste I.
Radiation of the low neck can be accomplished using split-field intensity-modulated radiation therapy (sf-IMRT) or extended-field intensity-modulated radiation therapy (ef-IMRT). We evaluated the effect of these treatment choices on target coverage and thyroid and larynx doses. Using data from 14 patients with cancers of the oropharynx, we compared the following 3 strategies for radiating the low neck: (1) extended-field IMRT, (2) traditional split-field IMRT with an initial cord-junction block to 40 Gy, followed by a full-cord block to 50 Gy, and (3) split-field IMRT with a full-cord block to 50 Gy. Patients were planned using each of these 3 techniques.more » To facilitate comparison, extended-field plans were normalized to deliver 50 Gy to 95% of the neck volume. Target coverage was assessed using the dose to 95% of the neck volume (D{sub 95}). Mean thyroid and larynx doses were computed. Extended-field IMRT was used as the reference arm; the mean larynx dose was 25.7 ± 7.4 Gy, and the mean thyroid dose was 28.6 ± 2.4 Gy. Split-field IMRT with 2-step blocking reduced laryngeal dose (mean larynx dose 15.2 ± 5.1 Gy) at the cost of a moderate reduction in target coverage (D{sub 95} 41.4 ± 14 Gy) and much higher thyroid dose (mean thyroid dose 44.7 ± 3.7 Gy). Split-field IMRT with initial full-cord block resulted in greater laryngeal sparing (mean larynx dose 14.2 ± 5.1 Gy) and only a moderately higher thyroid dose (mean thyroid dose 31 ± 8 Gy) but resulted in a significant reduction in target coverage (D{sub 95} 34.4 ± 15 Gy). Extended-field IMRT comprehensively covers the low neck and achieves acceptable thyroid and laryngeal sparing. Split-field IMRT with a full-cord block reduces laryngeal doses to less than 20 Gy and spares the thyroid, at the cost of substantially reduced coverage of the low neck. Traditional 2-step split-field IMRT similarly reduces the laryngeal dose but also reduces low-neck coverage and delivers very high doses to the thyroid.« less
Estimating the coverage of mental health programmes: a systematic review.
De Silva, Mary J; Lee, Lucy; Fuhr, Daniela C; Rathod, Sujit; Chisholm, Dan; Schellenberg, Joanna; Patel, Vikram
2014-04-01
The large treatment gap for people suffering from mental disorders has led to initiatives to scale up mental health services. In order to track progress, estimates of programme coverage, and changes in coverage over time, are needed. Systematic review of mental health programme evaluations that assess coverage, measured either as the proportion of the target population in contact with services (contact coverage) or as the proportion of the target population who receive appropriate and effective care (effective coverage). We performed a search of electronic databases and grey literature up to March 2013 and contacted experts in the field. Methods to estimate the numerator (service utilization) and the denominator (target population) were reviewed to explore methods which could be used in programme evaluations. We identified 15 735 unique records of which only seven met the inclusion criteria. All studies reported contact coverage. No study explicitly measured effective coverage, but it was possible to estimate this for one study. In six studies the numerator of coverage, service utilization, was estimated using routine clinical information, whereas one study used a national community survey. The methods for estimating the denominator, the population in need of services, were more varied and included national prevalence surveys case registers, and estimates from the literature. Very few coverage estimates are available. Coverage could be estimated at low cost by combining routine programme data with population prevalence estimates from national surveys.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Syh, J; Syh, J; Patel, B
Purpose: This case study was designated to confirm the optimized plan was used to treat skin surface of left leg in three stages. 1. To evaluate dose distribution and plan quality by alternating of the source loading catheters pattern in flexible Freiberg Flap skin surface (FFSS) applicator. 2. To investigate any impact on Dose Volume Histogram (DVH) of large superficial surface target volume coverage. 3. To compare the dose distribution if it was treated with electron beam. Methods: The Freiburg Flap is a flexible mesh style surface mold for skin radiation or intraoperative surface treatments. The Freiburg Flap consists ofmore » multiple spheres that are attached to each other, holding and guiding up to 18 treatment catheters. The Freiburg Flap also ensures a constant distance of 5mm from the treatment catheter to the surface. Three treatment trials with individual planning optimization were employed: 18 channels, 9 channels of FF and 6 MeV electron beam. The comparisons were highlighted in target coverage, dose conformity and dose sparing of surrounding tissues. Results: The first 18 channels brachytherapy plan was generated with 18 catheters inside the skin-wrapped up flap (Figure 1A). A second 9 catheters plan was generated associated with the same calculation points which were assigned to match prescription for target coverage as 18 catheters plan (Figure 1B). The optimized inverse plan was employed to reduce the dose to adjacent structures such as tibia or fibula. The comparison of DVH’s was depicted on Figure 2. External beam of electron RT plan was depicted in Figure 3. Overcall comparisons among these three were illustrated in Conclusion: The 9-channel Freiburg flap flexible skin applicator offers a reasonably acceptable plan without compromising the coverage. Electron beam was discouraged to use to treat curved skin surface because of low target coverage and high dose in adjacent tissues.« less
Baumbach, Andreas; Lansky, Alexandra J; Onuma, Yoshi; Asano, Taku; Johnson, Thomas; Anderson, Richard; Kiemeneij, Ferdinand; Zheng, Ming; Van Royen, Niels; Slagboom, Ton; Vlachojannis, Georg; Xu, Bo; Serruys, Patrick; Wijns, William
2018-06-12
Durable polymer drug-eluting stents (DP DES) may contribute to persistent inflammation, delayed endothelial healing and subsequent late DES thrombosis. The aim of this Optical Coherence Tomography (OCT) sub-study was to compare healing and neointimal coverage of a novel bioabsorbable polymer sirolimus-eluting stent (FIREHAWK®) (BP DES) versus the DP DES (XIENCE) at 90 days in an all comers patient population. The TARGET All Comers study is a prospective multicenter randomised post-market trial of 1656 patients randomised 1:1 to FIREHAWK or XIENCE at 21 centers in 10 European countries. The TARGET OCT sub-study enrolled 36 consecutive patients with 52 lesions at 6 centers proficient in OCT. Follow-up OCT was performed at 3 months or prior to revascularisation when occurring before the 3-month window. The substudy was designed for non-inferiority of the primary endpoint of neointimal thickness. At follow-up, the mean neointimal thickness by OCT (52 lesions, Firehawk, n=24; Xience, n=28), was not significantly different between groups (Firehawk 75.5μm vs Xience V 82.3 μm) meeting the primary endpoint of non-inferiority (Pnoninferiority<0.001). The percentage of stent strut coverage was high in both groups (strut level: 99.9% ± 0.3 vs 100% ± 0.1, p=0.26), and the proportion of malapposed struts (1.0±1.6% vs. 1.2±2.0%, p=0.51) was low in both groups. Based on OCT, the FIREHAWK BP DES has a similar healing response 3 months after implantation compared to the DP DES, with near complete strut coverage, moderate neointima formation and minimal strut malapposition.
SU-F-T-419: Evaluation of PlanIQ Feasibility DVH as Planning Objectives for Skull Base SBRT Patients
DOE Office of Scientific and Technical Information (OSTI.GOV)
Jiang, W; Wang, H; Chi, P
2016-06-15
Purpose: PlanIQ(Sun Nuclear Corporation) can provide feasibility measures on organs-at-risk(OARs) around the target based on depth, local anatomy density and energy of radiation beam used. This study is to test and evaluate PlanIQ feasibility DVHs as optimization objectives in the treatment planning process, and to investigate the potential to use them in routine clinical cases to improve planning efficiency. Methods: Two to three arcs VMAT Treatment plans were generated in Pinnacle based on PlanIQ feasibility DVH for six skull base patients who previously treated with SBRT. The PlanIQ feasibility DVH for each OAR consists of four zones – impossible (atmore » 100% target coverage), difficult, challenging and probable. Constrains to achieve DVH in difficult zone were used to start plan optimization. Further adjustment was made to improve coverage. The plan DVHs were compared to PlanIQ feasibility DVH to assess the dose received by 0%(D0), 5%(D5), 10%(D10) and 50%(D50) of the OAR volumes. Results: A total of 90 OARs were evaluated for 6 patients (mean 15 OARs, range 11–18 OARs). We used >98% PTV coverage as planning goal since it’s difficult to achieve 100% target coverage. For the generated plans, 96.7% of the OARs achieved D0 or D5 within difficult zone or impossible zone (ipsilateral OARs 93.5%, contralateral OARs 100%), while 90% and 65.6% of the OARs achieved D10 and D50 within difficult zone, respectively. Seventeen of the contralateral and out of field OARs achieved DVHs in impossible zone. For OARs adjacent or overlapped with target volume, the D0 and D5 are challenging to be optimized into difficult zone. All plans were completed within 2–4 adjustments to improve target coverage and uniformity. Conclusion: PlanIQ feasibility tool has the potential to provide difficult but achievable initial optimization objectives and therefore reduce the planning time to obtain a well optimized plan.« less
TU-AB-BRB-02: Stochastic Programming Methods for Handling Uncertainty and Motion in IMRT Planning
DOE Office of Scientific and Technical Information (OSTI.GOV)
Unkelbach, J.
The accepted clinical method to accommodate targeting uncertainties inherent in fractionated external beam radiation therapy is to utilize GTV-to-CTV and CTV-to-PTV margins during the planning process to design a PTV-conformal static dose distribution on the planning image set. Ideally, margins are selected to ensure a high (e.g. >95%) target coverage probability (CP) in spite of inherent inter- and intra-fractional positional variations, tissue motions, and initial contouring uncertainties. Robust optimization techniques, also known as probabilistic treatment planning techniques, explicitly incorporate the dosimetric consequences of targeting uncertainties by including CP evaluation into the planning optimization process along with coverage-based planning objectives. Themore » treatment planner no longer needs to use PTV and/or PRV margins; instead robust optimization utilizes probability distributions of the underlying uncertainties in conjunction with CP-evaluation for the underlying CTVs and OARs to design an optimal treated volume. This symposium will describe CP-evaluation methods as well as various robust planning techniques including use of probability-weighted dose distributions, probability-weighted objective functions, and coverage optimized planning. Methods to compute and display the effect of uncertainties on dose distributions will be presented. The use of robust planning to accommodate inter-fractional setup uncertainties, organ deformation, and contouring uncertainties will be examined as will its use to accommodate intra-fractional organ motion. Clinical examples will be used to inter-compare robust and margin-based planning, highlighting advantages of robust-plans in terms of target and normal tissue coverage. Robust-planning limitations as uncertainties approach zero and as the number of treatment fractions becomes small will be presented, as well as the factors limiting clinical implementation of robust planning. Learning Objectives: To understand robust-planning as a clinical alternative to using margin-based planning. To understand conceptual differences between uncertainty and predictable motion. To understand fundamental limitations of the PTV concept that probabilistic planning can overcome. To understand the major contributing factors to target and normal tissue coverage probability. To understand the similarities and differences of various robust planning techniques To understand the benefits and limitations of robust planning techniques.« less
Chen, Yi-Jen; Liu, An; Han, Chunhui; Tsai, Peter T; Schultheiss, Timothy E; Pezner, Richard D; Vora, Nilesh; Lim, Dean; Shibata, Stephen; Kernstine, Kemp H; Wong, Jeffrey Y C
2007-01-01
We compare different radiotherapy techniques-helical tomotherapy (tomotherapy), step-and-shoot IMRT (IMRT), and 3-dimensional conformal radiotherapy (3DCRT)-for patients with mid-distal esophageal carcinoma on the basis of dosimetric analysis. Six patients with locally advanced mid-distal esophageal carcinoma were treated with neoadjuvant chemoradiation followed by surgery. Radiotherapy included 50 Gy to gross planning target volume (PTV) and 45 Gy to elective PTV in 25 fractions. Tomotherapy, IMRT, and 3DCRT plans were generated. Dose-volume histograms (DVHs), homogeneity index (HI), volumes of lung receiving more than 10, 15, or 20 Gy (V(10), V(15), V(20)), and volumes of heart receiving more than 30 or 45 Gy (V(30), V(45)) were determined. Statistical analysis was performed by paired t-tests. By isodose distributions and DVHs, tomotherapy plans showed sharper dose gradients, more conformal coverage, and better HI for both gross and elective PTVs compared with IMRT or 3DCRT plans. Mean V(20) of lung was significantly reduced in tomotherapy plans. However, tomotherapy and IMRT plans resulted in larger V(10) of lung compared to 3DCRT plans. The heart was significantly spared in tomotherapy and IMRT plans compared to 3DCRT plans in terms of V(30) and V(45). We conclude that tomotherapy plans are superior in terms of target conformity, dose homogeneity, and V(20) of lung.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Ashenafi, M; Koch, N; Peng, J
Purpose: We performed a comparative planning study among High Dose Rate (HDR) brachytherapy, superficial electrons, Volume Modulated Arc Therapy (VMAT), and Helical IMRT (Tomotherapy) for squamous cell carcinoma of the abdominal wall with consideration for the underlining bowel. Methods: A 69-year old female presented with squamous cell carcinoma protruding 8mm beyond the anterior skin surface of the midabdomen was considered for treatment. The patient had a ventral hernia which resulted in the reduction of the abdominal wall thickness and the adjacent small bowel being the dose limiting structure. Four plans were generated using different treatment modalities: a) an enface electronmore » field (eMC, Eclipse v. 11), b) Tomotherapy (HI-Art II v.5.0.5), c) VMAT (Acuros, Eclipse v. 11), and d) HDR using a Freiburg applicator (Oncentra v. 4.3). The following plan objectives were used for all four plans: for the CTV target, V90% ≥90% (61.8Gy2/2).For the small bowel, D0.1cc < 56.2 Gy2/2 was a hard constraint and expressed as a percentage of the prescription for comparison to demonstrate the dose fall-off achieved among the modalities.For HDR, V200% <0.1cc was an additional constraint. Multiple dosimetric parameters, including those listed above, were compared among the four modalities. Results: The HDR plan showed comparable target coverage compared to the Tomotherapy plan and better coverage compared to the electron plan. Small bowel doses (D0.1cc) were lower in HDR plan compared to Tomotherapy, electron, & VMAT plans (88.8%, 89.6%, 90.9%, & 96.6%). Integral dose to the whole body (V5%) was much higher for HDR, VMAT, and Tomotherapy when compared to electron plan by factors of seven, eight, and ten, respectively. After reviewing all treatment modalities, the physician selected HDR owing to better control of the small bowel dose while maintaining adequate target coverage. Conclusion: This case study demonstrated HDR can successfully treat superficial lesions with superior sparing of underlying structures.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Bejarano Buele, A; Parsai, E
Purpose: The target volume for Whole Breast Irradiation (WBI) is dictated by location of tumor mass, breast tissue distribution, and involvement of lymph nodes. Dose coverage and Organs at Risk (OARs) sparing can be difficult to achieve in patients with unfavorable thoracic geometries. For these cases, inverse-planned and 3D-conformal prone treatments can be alternatives to traditional supine 3D-conformal plans. A dosimetric comparison can determine which of these techniques achieve optimal target coverage while sparing OARs. Methods: This study included simulation datasets for 8 patients, 5 of whom were simulated in both supine and prone positions. Positioning devices included breast boardsmore » and Vaclok bags for the supine position, and prone breast boards for the prone position. WBI 3-D conformal plans were created for patients simulated in both positions. Additional VMAT and IMRT WBI plans were made for all patients in the supine position. Results: Prone and supine 3D conformal plans had comparable PTV coverage. Prone 3D conformal plans received a significant 50% decrease to V20, V10, V5 and V30% for the ipsilateral lung in contrast to the supine plans. The heart also experienced a 10% decrease in maximum dose in the prone position, and V20, V10, V5 and V2 had significantly lower values than the supine plan. Supine IMRT and VMAT breast plans obtained comparable PTV coverage. The heart experienced a 10% decrease in maximum dose with inverse modulated plans when compared to the supine 3D conformal plan, while V20, V10, V5 and V2 showed higher values with inverse modulated plans than with supine 3D conformal plans. Conclusion: Prone 3D-conformal, and supine inverse planned treatments were generally superior in sparing OARs to supine plans with comparable PTV coverage. IMRT and VMAT plans offer sparing of OARs from high dose regions with an increase of irradiated volume in the low dose regions.« less
Wilson, Elizabeth Ruth; Kyle, Theodore K; Nadglowski, Joseph F; Stanford, Fatima Cody
2017-02-01
Evidence-based obesity treatments, such as bariatric surgery, are not considered essential health benefits under the Affordable Care Act. Employer-sponsored wellness programs with incentives based on biometric outcomes are allowed and often used despite mixed evidence regarding their effectiveness. This study examines consumers' perceptions of their coverage for obesity treatments and exposure to workplace wellness programs. A total of 7,378 participants completed an online survey during 2015-2016. Respondents answered questions regarding their health coverage for seven medical services and exposure to employer wellness programs that target weight or body mass index (BMI). Using χ 2 tests, associations between perceptions of exposure to employer wellness programs and coverage for medical services were examined. Differences between survey years were also assessed. Most respondents reported they did not have health coverage for obesity treatments, but more of the respondents with employer wellness programs reported having coverage. Neither the perception of coverage for obesity treatments nor exposure to wellness programs increased between 2015 and 2016. Even when consumers have exposure to employer wellness programs that target BMI, their health insurance often excludes obesity treatments. Given the clinical and cost-effectiveness of such treatments, reducing that coverage gap may mitigate obesity's individual- and population-level effects. © 2017 The Obesity Society.
42 CFR 436.229 - Optional targeted low-income children.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 42 Public Health 4 2011-10-01 2011-10-01 false Optional targeted low-income children. 436.229... Options for Coverage as Categorically Needy Options for Coverage of Families and Children and Aged, Blind, and Disabled Individuals, Including Pregnant Women § 436.229 Optional targeted low-income children...
42 CFR 436.229 - Optional targeted low-income children.
Code of Federal Regulations, 2010 CFR
2010-10-01
... 42 Public Health 4 2010-10-01 2010-10-01 false Optional targeted low-income children. 436.229... Options for Coverage as Categorically Needy Options for Coverage of Families and Children and Aged, Blind, and Disabled Individuals, Including Pregnant Women § 436.229 Optional targeted low-income children...
42 CFR 436.229 - Optional targeted low-income children.
Code of Federal Regulations, 2013 CFR
2013-10-01
... 42 Public Health 4 2013-10-01 2013-10-01 false Optional targeted low-income children. 436.229... Options for Coverage as Categorically Needy Options for Coverage of Families and Children and Aged, Blind, and Disabled Individuals, Including Pregnant Women § 436.229 Optional targeted low-income children...
42 CFR 436.229 - Optional targeted low-income children.
Code of Federal Regulations, 2012 CFR
2012-10-01
... 42 Public Health 4 2012-10-01 2012-10-01 false Optional targeted low-income children. 436.229... Options for Coverage as Categorically Needy Options for Coverage of Families and Children and Aged, Blind, and Disabled Individuals, Including Pregnant Women § 436.229 Optional targeted low-income children...
42 CFR 436.229 - Optional targeted low-income children.
Code of Federal Regulations, 2014 CFR
2014-10-01
... 42 Public Health 4 2014-10-01 2014-10-01 false Optional targeted low-income children. 436.229... Options for Coverage as Categorically Needy Options for Coverage of Families and Children and Aged, Blind, and Disabled Individuals, Including Pregnant Women § 436.229 Optional targeted low-income children...
NASA Astrophysics Data System (ADS)
Moteabbed, M.; Trofimov, A.; Sharp, G. C.; Wang, Y.; Zietman, A. L.; Efstathiou, J. A.; Lu, H.-M.
2017-03-01
Proton therapy of prostate by anterior beams could offer an attractive option for treating patients with hip prosthesis and limiting the high-dose exposure to the rectum. We investigated the impact of setup and anatomy variations on the anterior-oblique (AO) proton plan dose, and strategies to manage these effects via range verification and adaptive delivery. Ten patients treated by bilateral (BL) passive-scattering proton therapy (79.2 Gy in 44 fractions) who underwent weekly verification CT scans were selected. Plans with AO beams were additionally created. To isolate the effect of daily variations, initial AO plans did not include range uncertainty margins. The use of fixed planning margins and adaptive range adjustments to manage these effects was investigated. For each case, the planned dose was recalculated on weekly CTs, and accumulated on the simulation CT using deformable registration to approximate the delivered dose. Planned and accumulated doses were compared for each scenario to quantify dose deviations induced by variations. The possibility of estimating the necessary range adjustments before each treatment was explored by simulating the procedure of a diode-based in vivo range verification technique, which would potentially be used clinically. The average planned rectum, penile bulb and femoral heads mean doses were smaller for initial AO compared to BL plans (by 8.3, 16.1 and 25.9 Gy, respectively). After considering interfractional variations in AO plans, the target coverage was substantially reduced. The maximum reduction of V 79.2/D 95/D mean/EUD for AO (without distal margins) (25.3%/10.7/1.6/4.9 Gy, respectively) was considerably larger than BL plans. The loss of coverage was mainly related to changes in water equivalent path length of the prostate after fiducial-based setup, caused by discrepancies in patient anterior surface and bony-anatomy alignment. Target coverage was recovered partially when using fixed planning margins, and fully when applying adaptive range adjustments. The accumulated organs-at-risk dose for AO beams after range adjustment demonstrated full sparing of femoral heads and superior sparing of penile bulb and rectum compared to the conventional BL cases. Our study indicates that using AO beams makes prostate treatment more susceptible to target underdose induced by interfractional variations. Adaptive range verification/adjustment may facilitate the use of anterior beam approaches, and ensure adequate target coverage in every fraction of the treatment.
Ho, Evangeline S Q; Barrett, Sarah A; Mullaney, Laura M
2017-08-01
Craniospinal irradiation (CSI) is the standard radiation therapy treatment for medulloblastoma. Conventional CSI photon therapy (Photon-CSI) delivers significant dose to surrounding normal tissue (NT). Research into pediatric CSI with proton therapy (Proton-CSI) has increased, with the aim of exploiting the potential to reduce NT dose and associated post-treatment complications. This review aims to compare treatment outcomes of pediatric medulloblastoma patients between Proton- and Photon-CSI treatments. A search and review of studies published between 1990 and 2016 comparing pediatric (2-18 years) medulloblastoma Proton- and Photon-CSI in three aspects - normal organ sparing and target coverage; normal organ dysfunction and second malignancy risks - was completed. Fifteen studies were selected for review and the results were directly compared. Proton-CSI reported improved out-of-field organ sparing while target coverage improvements were inconsistent. Normal organ dysfunction risks were predicted to be lower following Proton-CSI. Secondary malignancy risks (SMRs) were generally lower with Proton-CSI based on several different risk models. Proton-CSI conferred better treatment outcomes than Photon-CSI for pediatric medulloblastoma patients. This review serves to compare the current literature in the absence of long-term data from prospective studies.
Estimating the coverage of mental health programmes: a systematic review
De Silva, Mary J; Lee, Lucy; Fuhr, Daniela C; Rathod, Sujit; Chisholm, Dan; Schellenberg, Joanna; Patel, Vikram
2014-01-01
Background The large treatment gap for people suffering from mental disorders has led to initiatives to scale up mental health services. In order to track progress, estimates of programme coverage, and changes in coverage over time, are needed. Methods Systematic review of mental health programme evaluations that assess coverage, measured either as the proportion of the target population in contact with services (contact coverage) or as the proportion of the target population who receive appropriate and effective care (effective coverage). We performed a search of electronic databases and grey literature up to March 2013 and contacted experts in the field. Methods to estimate the numerator (service utilization) and the denominator (target population) were reviewed to explore methods which could be used in programme evaluations. Results We identified 15 735 unique records of which only seven met the inclusion criteria. All studies reported contact coverage. No study explicitly measured effective coverage, but it was possible to estimate this for one study. In six studies the numerator of coverage, service utilization, was estimated using routine clinical information, whereas one study used a national community survey. The methods for estimating the denominator, the population in need of services, were more varied and included national prevalence surveys case registers, and estimates from the literature. Conclusions Very few coverage estimates are available. Coverage could be estimated at low cost by combining routine programme data with population prevalence estimates from national surveys. PMID:24760874
DOE Office of Scientific and Technical Information (OSTI.GOV)
Briscoe, M; Ploquin, N; Voroney, JP
2015-06-15
Purpose: To quantify the effect of patient rotation in stereotactic radiation therapy and establish a threshold where rotational patient set-up errors have a significant impact on target coverage. Methods: To simulate rotational patient set-up errors, a Matlab code was created to rotate the patient dose distribution around the treatment isocentre, located centrally in the lesion, while keeping the structure contours in the original locations on the CT and MRI. Rotations of 1°, 3°, and 5° for each of the pitch, roll, and yaw, as well as simultaneous rotations of 1°, 3°, and 5° around all three axes were applied tomore » two types of brain lesions: brain metastasis and acoustic neuroma. In order to analyze multiple tumour shapes, these plans included small spherical (metastasis), elliptical (acoustic neuroma), and large irregular (metastasis) tumour structures. Dose-volume histograms and planning target volumes were compared between the planned patient positions and those with simulated rotational set-up errors. The RTOG conformity index for patient rotation was also investigated. Results: Examining the tumour volumes that received 80% of the prescription dose in the planned and rotated patient positions showed decreases in prescription dose coverage of up to 2.3%. Conformity indices for treatments with simulated rotational errors showed decreases of up to 3% compared to the original plan. For irregular lesions, degradation of 1% of the target coverage can be seen for rotations as low as 3°. Conclusions: This data shows that for elliptical or spherical targets, rotational patient set-up errors less than 3° around any or all axes do not have a significant impact on the dose delivered to the target volume or the conformity index of the plan. However the same rotational errors would have an impact on plans for irregular tumours.« less
NSW Annual Immunisation Coverage Report, 2009.
Hull, Brynley; Dey, Aditi; Mahajan, Deepika; Campbell-Lloyd, Sue; Menzies, Robert I; McIntyre, Peter B
2010-01-01
This is the first in a series of annual immunisation coverage reports that document trends in NSW for a range of standard measures derived from Australian Childhood Immunisation Register data, including overall coverage at standard age milestones and for individual vaccines. This report includes data up to and including 2009. Data from the Australian Childhood Immunisation Register, the NSW Health Survey and the NSW School Immunisation Program were used to calculate various measures of population coverage relating to childhood vaccines, adult influenza and pneumococcal vaccines and adolescent vaccination, respectively. Immunise Australia Program targets have been reached for children at 12 and 24 months of age but not for children at 5 years of age. Delayed receipt of vaccines is an issue for vaccines recommended for Aboriginal children. Pneumococcal vaccination in the elderly has been steadily rising, although it has remained lower than the influenza coverage estimates. For adolescents, there is better coverage for the first and second doses of human papillomavirus vaccine and the dose of dTpa than for varicella. This comprehensive analysis provides important baseline data for NSW against which future reports can be compared to monitor progress in improving immunisation coverage. Immunisation at the earliest appropriate age should be a public health goal for countries such as Australia where high levels of vaccine coverage at milestone ages have been achieved.
77 FR 31814 - National Flood Insurance Program (NFIP); Insurance Coverage and Rates
Federal Register 2010, 2011, 2012, 2013, 2014
2012-05-30
... structures (target repetitive loss buildings) insured under the NFIP. The Notice of Proposed Rulemaking (NPRM) defined target repetitive loss buildings as those with four or more losses, or with two or more flood... flood insurance coverage to a target repetitive loss building, if an owner declined an offer of...
Pezzoli, Lorenzo; Conteh, Ishata; Kamara, Wogba; Gacic-Dobo, Marta; Ronveaux, Olivier; Perea, William A; Lewis, Rosamund F
2012-06-07
In November 2009, Sierra Leone conducted a preventive yellow fever (YF) vaccination campaign targeting individuals aged nine months and older in six health districts. The campaign was integrated with a measles follow-up campaign throughout the country targeting children aged 9-59 months. For both campaigns, the operational objective was to reach 95% of the target population. During the campaign, we used clustered lot quality assurance sampling (C-LQAS) to identify areas of low coverage to recommend timely mop-up actions. We divided the country in 20 non-overlapping lots. Twelve lots were targeted by both vaccinations, while eight only by measles. In each lot, five clusters of ten eligible individuals were selected for each vaccine. The upper threshold (UT) was set at 90% and the lower threshold (LT) at 75%. A lot was rejected for low vaccination coverage if more than 7 unvaccinated individuals (not presenting vaccination card) were found. After the campaign, we plotted the C-LQAS results against the post-campaign coverage estimations to assess if early interventions were successful enough to increase coverage in the lots that were at the level of rejection before the end of the campaign. During the last two days of campaign, based on card-confirmed vaccination status, five lots out of 20 (25.0%) failed for having low measles vaccination coverage and three lots out of 12 (25.0%) for low YF coverage. In one district, estimated post-campaign vaccination coverage for both vaccines was still not significantly above the minimum acceptable level (LT = 75%) even after vaccination mop-up activities. C-LQAS during the vaccination campaign was informative to identify areas requiring mop-up activities to reach the coverage target prior to leaving the region. The only district where mop-up activities seemed to be unsuccessful might have had logistical difficulties that should be further investigated and resolved.
Fujimoto, Koya; Shiinoki, Takehiro; Yuasa, Yuki; Hanazawa, Hideki; Shibuya, Keiko
2017-06-01
A commercially available bolus ("commercial-bolus") does not make complete contact with the irregularly shaped patient skin. This study aims to customise a patient-specific three-dimensional (3D) bolus using a 3D printing technique ("3D-bolus") and to evaluate its clinical feasibility for photon radiotherapy. The 3D-bolus was designed using a treatment planning system (TPS) in Digital Imaging and Communications in Medicine-Radiotherapy (DICOM-RT) format, and converted to stereolithographic format for printing. To evaluate its physical characteristics, treatment plans were created for water-equivalent phantoms that were bolus-free, or had a flat-form printed 3D-bolus, a TPS-designed bolus ("virtual-bolus"), or a commercial-bolus. These plans were compared based on the percentage depth dose (PDD) and target-volume dose volume histogram (DVH) measurements. To evaluate the clinical feasibility, treatment plans were created for head phantoms that were bolus-free or had a 3D-bolus, a virtual-bolus, or a commercial-bolus. These plans were compared based on the target volume DVH. In the physical evaluation, the 3D-bolus provided effective dose coverage in the build-up region, which was equivalent to the commercial-bolus. With regard to the clinical feasibility, the air gaps were lesser with the 3D-bolus when compared to the commercial-bolus. Furthermore, the prescription dose could be delivered appropriately to the target volume. The 3D-bolus has potential use for air-gap reduction compared to the commercial-bolus and facilitates target-volume dose coverage and homogeneity improvement. A 3D-bolus produced using a 3D printing technique is comparable to a commercial-bolus applied to an irregular-shaped skin surface. Copyright © 2017 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Liu, W; Shen, J; Stoker, J
2015-06-15
Purpose: To compare the impact of interplay effect on 3D and 4D robustly optimized intensity-modulated proton therapy (IMPT) plans to treat lung cancer. Methods: Two IMPT plans were created for 11 non-small-cell-lung-cancer cases with 6–14 mm spots. 3D robust optimization generated plans on average CTs with the internal gross tumor volume density overridden to deliver 66 CGyE in 33 fractions to the internal target volume (ITV). 4D robust optimization generated plans on 4D CTs with the delivery of prescribed dose to the clinical target volume (CTV). In 4D optimization, the CTV of individual 4D CT phases received non-uniform doses tomore » achieve a uniform cumulative dose. Dose evaluation software was developed to model time-dependent spot delivery to incorporate interplay effect with randomized starting phases of each field per fraction. Patient anatomy voxels were mapped from phase to phase via deformable image registration to score doses. Indices from dose-volume histograms were used to compare target coverage, dose homogeneity, and normal-tissue sparing. DVH indices were compared using Wilcoxon test. Results: Given the presence of interplay effect, 4D robust optimization produced IMPT plans with better target coverage and homogeneity, but slightly worse normal tissue sparing compared to 3D robust optimization (unit: Gy) [D95% ITV: 63.5 vs 62.0 (p=0.014), D5% - D95% ITV: 6.2 vs 7.3 (p=0.37), D1% spinal cord: 29.0 vs 29.5 (p=0.52), Dmean total lung: 14.8 vs 14.5 (p=0.12), D33% esophagus: 33.6 vs 33.1 (p=0.28)]. The improvement of target coverage (D95%,4D – D95%,3D) was related to the ratio RMA3/(TVx10−4), with RMA and TV being respiratory motion amplitude (RMA) and tumor volume (TV), respectively. Peak benefit was observed at ratios between 2 and 10. This corresponds to 125 – 625 cm3 TV with 0.5-cm RMA. Conclusion: 4D optimization produced more interplay-effect-resistant plans compared to 3D optimization. It is most effective when respiratory motion is modest compared to TV. NIH/NCI K25CA168984; Eagles Cancer Research Career Development; The Lawrence W. and Marilyn W. Matteson Fund for Cancer Research; Mayo ASU Seed Grant; The Kemper Marley Foundation.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Moignier, A; Gelover, E; Wang, D
Purpose: A dynamic collimation system (DCS) based on two orthogonal pairs of mobile trimmer blades has recently been proposed to reduce the lateral penumbra in spot scanning proton therapy (SSPT). The purpose of this work is to quantify the therapeutic benefit of using the DCS for SSPT of brain cancer by comparing un-collimated and collimated treatment plans. Methods: Un-collimated and collimated brain treatment plans were created for five patients, previously treated with SSPT, using an in-house treatment planning system capable of modeling collimated and un-collimated beamlets. Un-collimated plans reproduced the clinically delivered plans in terms of target coverage and organ-at-riskmore » (OAR) sparing, whereas collimated plans were re-optimized to improve the organ-at-risk sparing while maintaining target coverage. Physical and biological comparison metrics such as dose distribution conformity, mean and maximum doses, normal tissue complication probability (NTCP) and risk of secondary brain cancer were used to evaluate the plans. Results: The DCS systematically improved the dose distribution conformity while preserving the target coverage. The average reduction of the mean dose to the 10-mm ring surrounding the target and the healthy brain were 7.1% (95% CI: 4.2%–9.9%; p<0.01) and 14.3% (95% CI: 7.8%–20.8%; p<0.01), respectively. This yielded an average reduction of 12.0% (95% CI: 8.2%–15.7%; p<0.01) for the brain necrosis NTCP using the Flickinger model, and 14.2% (95% CI: 7.7%–20.8%; p<0.01) for the risk of secondary brain cancer. The average maximum dose reductions for the brainstem, chiasm, optic nerves, cochleae and pituitary gland when comparing un-collimated and collimated plans were 14.3%, 10.4%, 11.2%, 13.0%, 12.9% and 3.4%, respectively. Evaluating individual plans using the Lyman-Kutcher-Burman NTCP model also yielded improvements. Conclusion: The lateral penumbra reduction performed by the DCS increases the normal tissue sparing capabilities of SSPT for brain tumor treatment while preserving the target coverage. This research was financially supported by Ion Beam Applications S.A. (IBA, Louvain-La-Neuve, Belgium)« less
SU-F-T-443: Quantification of Dosimetric Effects of Dental Metallic Implant On VMAT Plans
DOE Office of Scientific and Technical Information (OSTI.GOV)
Lin, C; Jiang, W; Feng, Y
Purpose: To evaluate the dosimetric impact of metallic implant that correlates with the size of targets and metallic implants and distance in between on volumetric-modulated arc therapy (VMAT) plans for head and neck (H&N) cancer patients with dental metallic implant. Methods: CT images of H&N cancer patients with dental metallic implant were used. Target volumes with different sizes and locations were contoured. Metal artifact regions excluding surrounding critical organs were outlined and assigned with CT numbers close to water (0HU). VMAT plans with half-arc, one-full-arc and two-full-arcs were constructed and same plans were applied to structure sets with and withoutmore » CT number assignment of metal artifact regions and compared. D95% was utilized to investigate PTV dose coverage and SNC Patient− Software was used for the analysis of dose distribution difference slice by slice. Results: For different targets sizes, variation of PTV dose coverage (Delta-D95%) with and without CT number replacement reduced with larger target volume for all half-arc, one-arc and two-arc VMAT plans even though there were no clinically significant differences. Additionally, there were no significant variations of the maximum percent difference (max.%diff) of dose distribution. With regard to the target location, Delta-D95% and max. %diff dropped with increasing distance between target and metallic implant. Furthermore, half-arc plans showed greater impact than one-arc plans, and two-arc plans had smallest influence for PTV dose coverage and dose distribution. Conclusion: The target size has less correlation of doseimetric impact than the target location relative to metallic implants. Plans with more arcs alleviate the dosimetric effect of metal artifact because of less contribution to the target dose from beams going through the regions with metallic artifacts. Incorrect CT number causes inaccurate dose distribution, therefore appropriately overwriting metallic artifact regions with reasonable CT numbers is recommended. More patient data are collected and under further analysis.« less
Pezzoli, Lorenzo; Andrews, Nick; Ronveaux, Olivier
2010-05-01
Vaccination programmes targeting disease elimination aim to achieve very high coverage levels (e.g. 95%). We calculated the precision of different clustered lot quality assurance sampling (LQAS) designs in computer-simulated surveys to provide local health officers in the field with preset LQAS plans to simply and rapidly assess programmes with high coverage targets. We calculated sample size (N), decision value (d) and misclassification errors (alpha and beta) of several LQAS plans by running 10 000 simulations. We kept the upper coverage threshold (UT) at 90% or 95% and decreased the lower threshold (LT) progressively by 5%. We measured the proportion of simulations with < or =d individuals unvaccinated or lower if the coverage was set at the UT (pUT) to calculate beta (1-pUT) and the proportion of simulations with >d unvaccinated individuals if the coverage was LT% (pLT) to calculate alpha (1-pLT). We divided N in clusters (between 5 and 10) and recalculated the errors hypothesising that the coverage would vary in the clusters according to a binomial distribution with preset standard deviations of 0.05 and 0.1 from the mean lot coverage. We selected the plans fulfilling these criteria: alpha < or = 5% beta < or = 20% in the unclustered design; alpha < or = 10% beta < or = 25% when the lots were divided in five clusters. When the interval between UT and LT was larger than 10% (e.g. 15%), we were able to select precise LQAS plans dividing the lot in five clusters with N = 50 (5 x 10) and d = 4 to evaluate programmes with 95% coverage target and d = 7 to evaluate programmes with 90% target. These plans will considerably increase the feasibility and the rapidity of conducting the LQAS in the field.
Piot, Bram; Navin, Deepa; Krishnan, Nattu; Bhardwaj, Ashish; Sharma, Vivek; Marjara, Pritpal
2010-01-01
Objectives This study reports on the results of a large-scale targeted condom social marketing campaign in and around areas where female sex workers are present. The paper also describes the method that was used for the routine monitoring of condom availability in these sites. Methods The lot quality assurance sampling (LQAS) method was used for the assessment of the geographical coverage and quality of coverage of condoms in target areas in four states and along selected national highways in India, as part of Avahan, the India AIDS initiative. Results A significant general increase in condom availability was observed in the intervention area between 2005 and 2008. High coverage rates were gradually achieved through an extensive network of pharmacies and particularly of non-traditional outlets, whereas traditional outlets were instrumental in providing large volumes of condoms. Conclusion LQAS is seen as a valuable tool for the routine monitoring of the geographical coverage and of the quality of delivery systems of condoms and of health products and services in general. With a relatively small sample size, easy data collection procedures and simple analytical methods, it was possible to inform decision-makers regularly on progress towards coverage targets. PMID:20167732
Piot, Bram; Mukherjee, Amajit; Navin, Deepa; Krishnan, Nattu; Bhardwaj, Ashish; Sharma, Vivek; Marjara, Pritpal
2010-02-01
This study reports on the results of a large-scale targeted condom social marketing campaign in and around areas where female sex workers are present. The paper also describes the method that was used for the routine monitoring of condom availability in these sites. The lot quality assurance sampling (LQAS) method was used for the assessment of the geographical coverage and quality of coverage of condoms in target areas in four states and along selected national highways in India, as part of Avahan, the India AIDS initiative. A significant general increase in condom availability was observed in the intervention area between 2005 and 2008. High coverage rates were gradually achieved through an extensive network of pharmacies and particularly of non-traditional outlets, whereas traditional outlets were instrumental in providing large volumes of condoms. LQAS is seen as a valuable tool for the routine monitoring of the geographical coverage and of the quality of delivery systems of condoms and of health products and services in general. With a relatively small sample size, easy data collection procedures and simple analytical methods, it was possible to inform decision-makers regularly on progress towards coverage targets.
Trosman, Julia R; Weldon, Christine B; Kelley, R Kate; Phillips, Kathryn A
2015-03-01
Next-generation tumor sequencing (NGTS) panels, which include multiple established and novel targets across cancers, are emerging in oncology practice, but lack formal positive coverage by US payers. Lack of coverage may impact access and adoption. This study identified challenges of NGTS coverage by private payers. We conducted semi-structured interviews with 14 NGTS experts on potential NGTS benefits, and with 10 major payers, representing more than 125,000,000 enrollees, on NGTS coverage considerations. We used the framework approach of qualitative research for study design and thematic analyses and simple frequencies to further describe findings. All interviewed payers see potential NGTS benefits, but all noted challenges to formal coverage: 80% state that inherent features of NGTS do not fit the medical necessity definition required for coverage, 70% view NGTS as a bundle of targets versus comprehensive tumor characterization and may evaluate each target individually, and 70% express skepticism regarding new evidence methods proposed for NGTS. Fifty percent of payers expressed sufficient concerns about NGTS adoption and implementation that will preclude their ability to issue positive coverage policies. Payers perceive that NGTS holds significant promise but, in its current form, poses disruptive challenges to coverage policy frameworks. Proactive multidisciplinary efforts to define the direction for NGTS development, evidence generation, and incorporation into coverage policy are necessary to realize its promise and provide patient access. This study contributes to current literature, as possibly the first study to directly interview US payers on NGTS coverage and reimbursement. Copyright © 2015 by the National Comprehensive Cancer Network.
Trosman, Julia R.; Weldon, Christine B.; Kate Kelley, R.; Phillips, Kathryn A.
2015-01-01
Background Next-generation tumor sequencing (NGTS) panels, which include multiple established and novel targets across cancers, are emerging in oncology practice, but lack formal positive coverage by US payers. Lack of coverage may impact access and adoption. This study identified challenges of NGTS coverage by private payers. Methods We conducted semi-structured interviews with 14 NGTS experts on potential NGTS benefits, and with 10 major payers, representing more than 125,000,000 enrollees, on NGTS coverage considerations. We used the framework approach of qualitative research for study design and thematic analyses and simple frequencies to further describe findings. Results All interviewed payers see potential NGTS benefits, but all noted challenges to formal coverage: 80% state that inherent features of NGTS do not fit the medical necessity definition required for coverage, 70% view NGTS as a bundle of targets versus comprehensive tumor characterization and may evaluate each target individually, and 70% express skepticism regarding new evidence methods proposed for NGTS. Fifty percent of payers expressed sufficient concerns about NGTS adoption and implementation that will preclude their ability to issue positive coverage policies. Conclusions Payers perceive that NGTS holds significant promise but, in its current form, poses disruptive challenges to coverage policy frameworks. Proactive multidisciplinary efforts to define the direction for NGTS development, evidence generation, and incorporation into coverage policy are necessary to realize its promise and provide patient access. This study contributes to current literature, as possibly the first study to directly interview US payers on NGTS coverage and reimbursement. PMID:25736008
DOE Office of Scientific and Technical Information (OSTI.GOV)
Lin, T; Wang, L; Galloway, T
Purpose: Head and Neck cancer treatment with IMRT/VMAT has two choices: split-filed IMRT(SFI), in which the LAN is treated with a separate anterior field and the extended whole-field IMRT(WFI) in which LAN is included with the IMRT/VMAT field. This study shows that under the same dose limit criteria, choosing the technique becomes a critical issue if daily localization and immobilization altered the dose distribution. Methods: Nine common head-and-neck cancer cases were chosen to illustrate how the daily localization and immobilization uncertainties affect to choose between SFI and WFI. Both SFI and WFI at upper target coverage were generated with VMAT.more » For each case, the same planning criteria were applied to the target and critical structures; therefore, similar target coverage and dose falloff can be observed in both techniques. Thirty days of kV cone beam CT(CBCT) images on each case were also delineated with contralateral and ipsilateral target as well as larynx as critical structure. About 300 CBCT images with daily delivered doses were analyzed and compared in a form of dose-volume histograms. Results: While both plans for SFI and WFI with VMAT planning utilized and meet the criteria of D95>prescription dose and for not-involved larynx with mean dose <35Gy and V55<10%, the daily localization and immobilization has a great contribution to the resulted dose delivery. With WFI, the better daily contralateral and ipsilateral neck target coverage can reflect a simpler or shorter localization; however, a much superior avoidance (WFI: mean dose a 42.5Gy; SFI: mean dose a 18.9Gy) of the non-involved larynx from the SFI is preferred. Conclusion: Dosimetrically, SFI and WFI are equally well for head and Neck cancer treatment with VMAT technique; however, if considering the contribution of daily localization(CBCT) method uncertainties, SFI is better with sparing non-involved larynx and WFI has better target coverage.« less
Lutkenhaus, Lotte J; Visser, Jorrit; de Jong, Rianne; Hulshof, Maarten C C M; Bel, Arjan
2015-07-01
To account for variable bladder size during bladder cancer radiotherapy, a daily plan selection strategy was implemented. The aim of this study was to calculate the actually delivered dose using an adaptive strategy, compared to a non-adaptive approach. Ten patients were treated to the bladder and lymph nodes with an adaptive full bladder strategy. Interpolated delineations of bladder and tumor on a full and empty bladder CT scan resulted in five PTVs for which VMAT plans were created. Daily cone beam CT (CBCT) scans were used for plan selection. Bowel, rectum and target volumes were delineated on these CBCTs, and delivered dose for these was calculated using both the adaptive plan, and a non-adaptive plan. Target coverage for lymph nodes improved using an adaptive strategy. The full bladder strategy spared the healthy part of the bladder from a high dose. Average bowel cavity V30Gy and V40Gy significantly reduced with 60 and 69ml, respectively (p<0.01). Other parameters for bowel and rectum remained unchanged. Daily plan selection compared to a non-adaptive strategy yielded similar bladder coverage and improved coverage for lymph nodes, with a significant reduction in bowel cavity V30Gy and V40Gy only, while other sparing was limited. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.
Volumetric modulated arc radiotherapy for esophageal cancer.
Vivekanandan, Nagarajan; Sriram, Padmanaban; Kumar, S A Syam; Bhuvaneswari, Narayanan; Saranya, Kamalakannan
2012-01-01
A treatment planning study was performed to evaluate the performance of volumetric arc modulation with RapidArc (RA) against 3D conformal radiation therapy (3D-CRT) and conventional intensity-modulated radiation therapy (IMRT) techniques for esophageal cancer. Computed tomgraphy scans of 10 patients were included in the study. 3D-CRT, 4-field IMRT, and single-arc and double-arc RA plans were generated with the aim to spare organs at risk (OAR) and healthy tissue while enforcing highly conformal target coverage. The planning objective was to deliver 54 Gy to the planning target volume (PTV) in 30 fractions. Plans were evaluated based on target conformity and dose-volume histograms of organs at risk (lung, spinal cord, and heart). The monitor unit (MU) and treatment delivery time were also evaluated to measure the treatment efficiency. The IMRT plan improves target conformity and spares OAR when compared with 3D-CRT. Target conformity improved with RA plans compared with IMRT. The mean lung dose was similar in all techniques. However, RA plans showed a reduction in the volume of the lung irradiated at V(₂₀Gy) and V(₃₀Gy) dose levels (range, 4.62-17.98%) compared with IMRT plans. The mean dose and D(₃₅%) of heart for the RA plans were better than the IMRT by 0.5-5.8%. Mean V(₁₀Gy) and integral dose to healthy tissue were almost similar in all techniques. But RA plans resulted in a reduced low-level dose bath (15-20 Gy) in the range of 14-16% compared with IMRT plans. The average MU needed to deliver the prescribed dose by RA technique was reduced by 20-25% compared with IMRT technique. The preliminary study on RA for esophageal cancers showed improvements in sparing OAR and healthy tissue with reduced beam-on time, whereas only double-arc RA offered improved target coverage compared with IMRT and 3D-CRT plans. Copyright © 2012 American Association of Medical Dosimetrists. Published by Elsevier Inc. All rights reserved.
Dalton, Andrew R H; Vamos, Eszter P; Harris, Matthew J; Netuveli, Gopalakrishnan; Wachter, Robert M; Majeed, Azeem; Millett, Christopher
2014-01-01
The Patient Protection and Affordable Care Act (ACA) galvanised debate in the United States (US) over universal health coverage. Comparison with countries providing universal coverage may illustrate whether the ACA can improve health outcomes and reduce disparities. We aimed to compare quality and disparities in hypertension management by socio-economic position in the US and England, the latter of which has universal health care. We used data from the Health and Retirement Survey in the US, and the English Longitudinal Study for Aging from England, including non-Hispanic White respondents aged 50-64 years (US market-based v NHS) and >65 years (US-Medicare v NHS) with diagnosed hypertension. We compared blood pressure control to clinical guideline (140/90 mmHg) and audit (150/90 mmHg) targets; mean systolic and diastolic blood pressure and antihypertensive prescribing, and disparities in each by educational attainment, income and wealth, using regression models. There were no significant differences in aggregate achievement of clinical targets aged 50 to 65 years (US market-based vs. NHS--62.3% vs. 61.3% [p = 0.835]). There was, however, greater control in the US in patients aged 65 years and over (US Medicare vs. NHS--53.5% vs. 58.2% [p = 0.043]). England had no significant socioeconomic disparity in blood pressure control (60.9% vs. 63.5% [p = 0.588], high and low wealth aged ≥65 years). The US had socioeconomic differences in the 50-64 years group (71.7% vs. 55.2% [p = 0.003], high and low wealth); these were attenuated but not abolished in Medicare beneficiaries. Moves towards universal health coverage in the US may reduce disparities in hypertension management. The current situation, providing universal coverage for residents aged 65 years and over, may not be sufficient for equality in care.
Dalton, Andrew R. H.; Vamos, Eszter P.; Harris, Matthew J.; Netuveli, Gopalakrishnan; Wachter, Robert M.; Majeed, Azeem; Millett, Christopher
2014-01-01
Background The Patient Protection and Affordable Care Act (ACA) galvanised debate in the United States (US) over universal health coverage. Comparison with countries providing universal coverage may illustrate whether the ACA can improve health outcomes and reduce disparities. We aimed to compare quality and disparities in hypertension management by socio-economic position in the US and England, the latter of which has universal health care. Method We used data from the Health and Retirement Survey in the US, and the English Longitudinal Study for Aging from England, including non-Hispanic White respondents aged 50–64 years (US market-based v NHS) and >65 years (US-Medicare v NHS) with diagnosed hypertension. We compared blood pressure control to clinical guideline (140/90 mmHg) and audit (150/90 mmHg) targets; mean systolic and diastolic blood pressure and antihypertensive prescribing, and disparities in each by educational attainment, income and wealth, using regression models. Results There were no significant differences in aggregate achievement of clinical targets aged 50 to 65 years (US market-based vs. NHS- 62.3% vs. 61.3% [p = 0.835]). There was, however, greater control in the US in patients aged 65 years and over (US Medicare vs. NHS- 53.5% vs. 58.2% [p = 0.043]). England had no significant socioeconomic disparity in blood pressure control (60.9% vs. 63.5% [p = 0.588], high and low wealth aged ≥65 years). The US had socioeconomic differences in the 50–64 years group (71.7% vs. 55.2% [p = 0.003], high and low wealth); these were attenuated but not abolished in Medicare beneficiaries. Conclusion Moves towards universal health coverage in the US may reduce disparities in hypertension management. The current situation, providing universal coverage for residents aged 65 years and over, may not be sufficient for equality in care. PMID:24416171
Constrained motion model of mobile robots and its applications.
Zhang, Fei; Xi, Yugeng; Lin, Zongli; Chen, Weidong
2009-06-01
Target detecting and dynamic coverage are fundamental tasks in mobile robotics and represent two important features of mobile robots: mobility and perceptivity. This paper establishes the constrained motion model and sensor model of a mobile robot to represent these two features and defines the k -step reachable region to describe the states that the robot may reach. We show that the calculation of the k-step reachable region can be reduced from that of 2(k) reachable regions with the fixed motion styles to k + 1 such regions and provide an algorithm for its calculation. Based on the constrained motion model and the k -step reachable region, the problems associated with target detecting and dynamic coverage are formulated and solved. For target detecting, the k-step detectable region is used to describe the area that the robot may detect, and an algorithm for detecting a target and planning the optimal path is proposed. For dynamic coverage, the k-step detected region is used to represent the area that the robot has detected during its motion, and the dynamic-coverage strategy and algorithm are proposed. Simulation results demonstrate the efficiency of the coverage algorithm in both convex and concave environments.
Influenza vaccination coverage among US children from 2004/2005 to 2015/2016.
Tian, Changwei; Wang, Hua; Wang, Wenming; Luo, Xiaoming
2018-05-15
Quantify the influenza vaccine coverage is essential to identify emerging concerns and to immunization programs for targeting interventions. Data from National Health Interview Survey were used to estimate receipt of at least one dose of influenza vaccination among children 6 months to 17 years of age. Influenza vaccination coverage increased from 16.70% during 2004/2005 to 49.43% during 2015/2016 (3.18% per year, P < 0.001); however, the coverage increased slightly after 2010/2011. Children at high risk of influenza complications had higher influenza vaccination coverage than non at-risk children. Boys and girls had similar coverage each year. While the coverage increased from 2004/2005 to 2015/2016 for all age groups, the coverage decreased with age each year (-0.64 to -1.58% per age group). There was a higher and rapid increase of coverage in Northeast than Midwest, South and West. American Indian or Alaskan Native and Asian showed higher coverage than other race groups (White, Black/African American, Multiple race). Multivariable analysis showed that high-risk status and region had the greatest associations with levels of vaccine coverage. Although the influenza vaccination coverage among children had increased remarkably since 2004/2005, establishing more effective immunization programs are warranted to achieve the Healthy People 2020 target.
Jang, Si Young; Lalonde, Ron; Ozhasoglu, Cihat; Burton, Steven; Heron, Dwight; Huq, M Saiful
2016-09-08
We performed an evaluation of the CyberKnife InCise MLC by comparing plan qualities for single and multiple brain lesions generated using the first version of InCise MLC, fixed cone, and Iris collimators. We also investigated differences in delivery efficiency among the three collimators. Twenty-four patients with single or multiple brain mets treated previously in our clinic on a CyberKnife M6 using cone/Iris collimators were selected for this study. Treatment plans were generated for all lesions using the InCise MLC. Number of monitor units, delivery time, target coverage, conformity index, and dose falloff were compared between MLC- and clinical cone/Iris-based plans. Statistical analysis was performed using the non-parametric Wilcoxon-Mann-Whitney signed-rank test. The planning accuracy of the MLC-based plans was validated using chamber and film measurements. The InCise MLC-based plans achieved mean dose and target coverage comparable to the cone/Iris-based plans. Although the conformity indices of the MLC-based plans were slightly higher than those of the cone/Iris-based plans, beam delivery time for the MLC-based plans was shorter by 30% ~ 40%. For smaller targets or cases with OARs located close to or abutting target volumes, MLC-based plans provided inferior dose conformity compared to cone/Iris-based plans. The QA results of MLC-based plans were within 5% absolute dose difference with over 90% gamma passing rate using 2%/2 mm gamma criteria. The first version of InCise MLC could be a useful delivery modality, especially for clinical situations for which delivery time is a limiting factor or for multitarget cases. © 2016 The Authors.
Optimization of Craniospinal Irradiation for Pediatric Medulloblastoma Using VMAT and IMRT.
Al-Wassia, Rolina K; Ghassal, Noor M; Naga, Adly; Awad, Nesreen A; Bahadur, Yasir A; Constantinescu, Camelia
2015-10-01
Intensity-modulated radiotherapy (IMRT) and volumetric-modulated arc therapy (VMAT) provide highly conformal target radiation doses, but also expose large volumes of healthy tissue to low-dose radiation. With improving survival, more children with medulloblastoma (MB) are at risk of late adverse effects of radiotherapy, including secondary cancers. We evaluated the characteristics of IMRT and VMAT craniospinal irradiation treatment plans in children with standard-risk MB to compare radiation dose delivery to target organs and organs at risk (OAR). Each of 10 children with standard-risk MB underwent both IMRT and VMAT treatment planning. Dose calculations used inverse planning optimization with a craniospinal dose of 23.4 Gy followed by a posterior fossa boost to 55.8 Gy. Clinical and planning target volumes were demarcated on axial computed tomography images. Dose distributions to target organs and OAR for each planning technique were measured and compared with published dose-volume toxicity data for pediatric patients. All patients completed treatment planning for both techniques. Analyses and comparisons of dose distributions and dose-volume histograms for the planned target volumes, and dose delivery to the OAR for each technique demonstrated the following: (1) VMAT had a modest, but significantly better, planning target volume-dose coverage and homogeneity compared with IMRT; (2) there were different OAR dose-sparing profiles for IMRT versus VMAT; and (3) neither IMRT nor VMAT demonstrated dose reductions to the published pediatric dose limits for the eyes, the lens, the cochlea, the pituitary, and the brain. The use of both IMRT and VMAT provides good target tissue coverage and sparing of the adjacent tissue for MB. Both techniques resulted in OAR dose delivery within published pediatric dose guidelines, except those mentioned above. Pediatric patients with standard-risk MB remain at risk for late endocrinologic, sensory (auditory and visual), and brain functional impairments.
Killeen, Gerry F; Smith, Tom A; Ferguson, Heather M; Mshinda, Hassan; Abdulla, Salim; Lengeler, Christian; Kachur, Steven P
2007-01-01
Background Malaria prevention in Africa merits particular attention as the world strives toward a better life for the poorest. Insecticide-treated nets (ITNs) represent a practical means to prevent malaria in Africa, so scaling up coverage to at least 80% of young children and pregnant women by 2010 is integral to the Millennium Development Goals (MDG). Targeting individual protection to vulnerable groups is an accepted priority, but community-level impacts of broader population coverage are largely ignored even though they may be just as important. We therefore estimated coverage thresholds for entire populations at which individual- and community-level protection are equivalent, representing rational targets for ITN coverage beyond vulnerable groups. Methods and Findings Using field-parameterized malaria transmission models, we show that high (80% use) but exclusively targeted coverage of young children and pregnant women (representing <20% of the population) will deliver limited protection and equity for these vulnerable groups. In contrast, relatively modest coverage (35%–65% use, with this threshold depending on ecological scenario and net quality) of all adults and children, rather than just vulnerable groups, can achieve equitable community-wide benefits equivalent to or greater than personal protection. Conclusions Coverage of entire populations will be required to accomplish large reductions of the malaria burden in Africa. While coverage of vulnerable groups should still be prioritized, the equitable and communal benefits of wide-scale ITN use by older children and adults should be explicitly promoted and evaluated by national malaria control programmes. ITN use by the majority of entire populations could protect all children in such communities, even those not actually covered by achieving existing personal protection targets of the MDG, Roll Back Malaria Partnership, or the US President's Malaria Initiative. PMID:17608562
2012-01-01
Background In November 2009, Sierra Leone conducted a preventive yellow fever (YF) vaccination campaign targeting individuals aged nine months and older in six health districts. The campaign was integrated with a measles follow-up campaign throughout the country targeting children aged 9–59 months. For both campaigns, the operational objective was to reach 95% of the target population. During the campaign, we used clustered lot quality assurance sampling (C-LQAS) to identify areas of low coverage to recommend timely mop-up actions. Methods We divided the country in 20 non-overlapping lots. Twelve lots were targeted by both vaccinations, while eight only by measles. In each lot, five clusters of ten eligible individuals were selected for each vaccine. The upper threshold (UT) was set at 90% and the lower threshold (LT) at 75%. A lot was rejected for low vaccination coverage if more than 7 unvaccinated individuals (not presenting vaccination card) were found. After the campaign, we plotted the C-LQAS results against the post-campaign coverage estimations to assess if early interventions were successful enough to increase coverage in the lots that were at the level of rejection before the end of the campaign. Results During the last two days of campaign, based on card-confirmed vaccination status, five lots out of 20 (25.0%) failed for having low measles vaccination coverage and three lots out of 12 (25.0%) for low YF coverage. In one district, estimated post-campaign vaccination coverage for both vaccines was still not significantly above the minimum acceptable level (LT = 75%) even after vaccination mop-up activities. Conclusion C-LQAS during the vaccination campaign was informative to identify areas requiring mop-up activities to reach the coverage target prior to leaving the region. The only district where mop-up activities seemed to be unsuccessful might have had logistical difficulties that should be further investigated and resolved. PMID:22676225
DOE Office of Scientific and Technical Information (OSTI.GOV)
Levin, Daphne; Menhel, Janna; Alezra, Dror
2008-01-01
We compared 9-field, equispaced intensity modulated radiation therapy (IMRT), 4- to 5-field, directionally optimized IMRT, and 3-dimensional (3D) noncoplanar planning approaches for tumors of the maxillary sinus. Ten patients were planned retrospectively to compare the different treatment techniques. Prescription doses were 60 to 70 Gy. Critical structures contoured included optic nerves and chiasm, lacrimal glands, lenses, and retinas. As an aid for plan assessment, we introduced a new tool: Critical Organ Scoring Index (COSI), which allows quantitative evaluation of the tradeoffs between target coverage and critical organ sparing. This index was compared with other, commonly used conformity indices. For amore » reliable assessment of both tumor coverage and dose to critical organs in the different planning techniques, we introduced a 2D, graphical representation of COSI vs. conformity index (CI). Dose-volume histograms and mean, maximum, and minimum organ doses were also compared. IMRT plans delivered lower doses to ipsilateral structures, but were unable to spare them. 3D plans delivered less dose to contralateral structures, and were more homogeneous, as well. Both IMRT approaches gave similar results. In cases where choice of optimal plan was difficult, the novel 2D COSI-CI representation gave an accurate picture of the tradeoffs between target coverage and organ sparing, even in cases where other conformity indices failed. Due to their unique anatomy, maxillary sinus tumors may benefit more from a noncoplanar approach than from IMRT. The new graphical representation proposed is a quick, visual, reliable tool, which may facilitate the physician's choice of best treatment plan for a given patient.« less
Kammermeier, Jochen; Drury, Suzanne; James, Chela T; Dziubak, Robert; Ocaka, Louise; Elawad, Mamoun; Beales, Philip; Lench, Nicholas; Uhlig, Holm H; Bacchelli, Chiara; Shah, Neil
2014-11-01
Multiple monogenetic conditions with partially overlapping phenotypes can present with inflammatory bowel disease (IBD)-like intestinal inflammation. With novel genotype-specific therapies emerging, establishing a molecular diagnosis is becoming increasingly important. We have introduced targeted next-generation sequencing (NGS) technology as a prospective screening tool in children with very early onset IBD (VEOIBD). We evaluated the coverage of 40 VEOIBD genes in two separate cohorts undergoing targeted gene panel sequencing (TGPS) (n=25) and whole exome sequencing (WES) (n=20). TGPS revealed causative mutations in four genes (IL10RA, EPCAM, TTC37 and SKIV2L) discovered unexpected phenotypes and directly influenced clinical decision making by supporting as well as avoiding haematopoietic stem cell transplantation. TGPS resulted in significantly higher median coverage when compared with WES, fewer coverage deficiencies and improved variant detection across established VEOIBD genes. Excluding or confirming known VEOIBD genotypes should be considered early in the disease course in all cases of therapy-refractory VEOIBD, as it can have a direct impact on patient management. To combine both described NGS technologies would compensate for the limitations of WES for disease-specific application while offering the opportunity for novel gene discovery in the research setting. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Xu Huijun; Gordon, J. James; Siebers, Jeffrey V.
2011-02-15
Purpose: A dosimetric margin (DM) is the margin in a specified direction between a structure and a specified isodose surface, corresponding to a prescription or tolerance dose. The dosimetric margin distribution (DMD) is the distribution of DMs over all directions. Given a geometric uncertainty model, representing inter- or intrafraction setup uncertainties or internal organ motion, the DMD can be used to calculate coverage Q, which is the probability that a realized target or organ-at-risk (OAR) dose metric D{sub v} exceeds the corresponding prescription or tolerance dose. Postplanning coverage evaluation quantifies the percentage of uncertainties for which target and OAR structuresmore » meet their intended dose constraints. The goal of the present work is to evaluate coverage probabilities for 28 prostate treatment plans to determine DMD sampling parameters that ensure adequate accuracy for postplanning coverage estimates. Methods: Normally distributed interfraction setup uncertainties were applied to 28 plans for localized prostate cancer, with prescribed dose of 79.2 Gy and 10 mm clinical target volume to planning target volume (CTV-to-PTV) margins. Using angular or isotropic sampling techniques, dosimetric margins were determined for the CTV, bladder and rectum, assuming shift invariance of the dose distribution. For angular sampling, DMDs were sampled at fixed angular intervals {omega} (e.g., {omega}=1 deg., 2 deg., 5 deg., 10 deg., 20 deg.). Isotropic samples were uniformly distributed on the unit sphere resulting in variable angular increments, but were calculated for the same number of sampling directions as angular DMDs, and accordingly characterized by the effective angular increment {omega}{sub eff}. In each direction, the DM was calculated by moving the structure in radial steps of size {delta}(=0.1,0.2,0.5,1 mm) until the specified isodose was crossed. Coverage estimation accuracy {Delta}Q was quantified as a function of the sampling parameters {omega} or {omega}{sub eff} and {delta}. Results: The accuracy of coverage estimates depends on angular and radial DMD sampling parameters {omega} or {omega}{sub eff} and {delta}, as well as the employed sampling technique. Target |{Delta}Q|<1% and OAR |{Delta}Q|<3% can be achieved with sampling parameters {omega} or {omega}{sub eff}=20 deg., {delta}=1 mm. Better accuracy (target |{Delta}Q|<0.5% and OAR |{Delta}Q|<{approx}1%) can be achieved with {omega} or {omega}{sub eff}=10 deg., {delta}=0.5 mm. As the number of sampling points decreases, the isotropic sampling method maintains better accuracy than fixed angular sampling. Conclusions: Coverage estimates for post-planning evaluation are essential since coverage values of targets and OARs often differ from the values implied by the static margin-based plans. Finer sampling of the DMD enables more accurate assessment of the effect of geometric uncertainties on coverage estimates prior to treatment. DMD sampling with {omega} or {omega}{sub eff}=10 deg. and {delta}=0.5 mm should be adequate for planning purposes.« less
Xu, Huijun; Gordon, J James; Siebers, Jeffrey V
2011-02-01
A dosimetric margin (DM) is the margin in a specified direction between a structure and a specified isodose surface, corresponding to a prescription or tolerance dose. The dosimetric margin distribution (DMD) is the distribution of DMs over all directions. Given a geometric uncertainty model, representing inter- or intrafraction setup uncertainties or internal organ motion, the DMD can be used to calculate coverage Q, which is the probability that a realized target or organ-at-risk (OAR) dose metric D, exceeds the corresponding prescription or tolerance dose. Postplanning coverage evaluation quantifies the percentage of uncertainties for which target and OAR structures meet their intended dose constraints. The goal of the present work is to evaluate coverage probabilities for 28 prostate treatment plans to determine DMD sampling parameters that ensure adequate accuracy for postplanning coverage estimates. Normally distributed interfraction setup uncertainties were applied to 28 plans for localized prostate cancer, with prescribed dose of 79.2 Gy and 10 mm clinical target volume to planning target volume (CTV-to-PTV) margins. Using angular or isotropic sampling techniques, dosimetric margins were determined for the CTV, bladder and rectum, assuming shift invariance of the dose distribution. For angular sampling, DMDs were sampled at fixed angular intervals w (e.g., w = 1 degree, 2 degrees, 5 degrees, 10 degrees, 20 degrees). Isotropic samples were uniformly distributed on the unit sphere resulting in variable angular increments, but were calculated for the same number of sampling directions as angular DMDs, and accordingly characterized by the effective angular increment omega eff. In each direction, the DM was calculated by moving the structure in radial steps of size delta (=0.1, 0.2, 0.5, 1 mm) until the specified isodose was crossed. Coverage estimation accuracy deltaQ was quantified as a function of the sampling parameters omega or omega eff and delta. The accuracy of coverage estimates depends on angular and radial DMD sampling parameters omega or omega eff and delta, as well as the employed sampling technique. Target deltaQ/ < l% and OAR /deltaQ/ < 3% can be achieved with sampling parameters omega or omega eef = 20 degrees, delta =1 mm. Better accuracy (target /deltaQ < 0.5% and OAR /deltaQ < approximately 1%) can be achieved with omega or omega eff = 10 degrees, delta = 0.5 mm. As the number of sampling points decreases, the isotropic sampling method maintains better accuracy than fixed angular sampling. Coverage estimates for post-planning evaluation are essential since coverage values of targets and OARs often differ from the values implied by the static margin-based plans. Finer sampling of the DMD enables more accurate assessment of the effect of geometric uncertainties on coverage estimates prior to treatment. DMD sampling with omega or omega eff = 10 degrees and delta = 0.5 mm should be adequate for planning purposes.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Lian, J; Matney, J; Chao, E
2015-06-15
Purpose: TomoTherapy treatment has unique challenges in handling intrafractional motion compared to conventional LINAC. This study is aimed to gain a realistic and quantitative understanding of motion impact on TomoTherapy SBRT treatment of lung and prostate cancer patients. Methods: A 4D dose engine utilizing GPUs and including motion during treatment was developed for the efficient simulation of TomoTherapy delivered dosimetry. Two clinical CyberKnife lung cases with respiratory motion tracking and two prostate cases with a slower non-periodical organ motion treated by LINAC plus Calypso tracking were used in the study. For each disease site, one selected case has an averagemore » motion (6mm); the other has a large motion (10mm for lung and 15mm for prostate). SBRT of lung and prostate cases were re-planned on TomoTherapy with 12 Gyx4 fractions and 7Gyx5 fractions, respectively, all with 95% PTV coverage. Each case was planned with 4 jaw settings: 1) conventional 1cm static, 2) 2.5cm static, 3) 2.5cm dynamic, and 4) 5cm dynamic. The intrafractional rigid motion of the target was applied in the dose calculation of individual fractions of each plan and total dose was accumulated from multiple fractions. Results: For 1cm static jaw plans with motions applied, PTV coverage is related to motion type and amplitude. For SBRT patients with average motion (6mm), the PTV coverage remains > 95% for lung case and 74% for prostate case. For cases with large motion, PTV coverage drops to 61% for lung SBRT and 49% for prostate SBRT. Plans with other jaws improve uniformity of moving target, but still suffer from poor PTV coverage (< 70%). Conclusion: TomoTherapy lung SBRT is less motion-impacted when average amplitude of respiratory-induced intrafractional motion is present (6mm). When motion is large and/or non-periodic (prostate), all studied plans lead to significantly decreased target coverage in actual delivered dosimetry.« less
Palache, A; Abelin, A; Hollingsworth, R; Cracknell, W; Jacobs, C; Tsai, T; Barbosa, P
2017-08-24
There is no global monitoring system for influenza vaccination coverage, making it difficult to assess progress towards the 2003 World Health Assembly (WHA) vaccination coverage target. In 2008, the IFPMA Influenza Vaccine Supply International Task Force (IVS) developed a survey method to assess the global distribution of influenza vaccine doses as a proxy for vaccination coverage rates. The latest dose distribution data for 2014 and 2015 was used to update previous analyses. Data were confidentially collected and aggregated by the IFPMA Secretariat, and combined with previous IFPMA IVS survey data (2004-2013). Data were available from 201 countries over the 2004-2015 period. A "hurdle" rate was defined as the number of doses required to reach 15.9% of the population in 2008. Overall, the number of distributed doses progressively increased between 2004 and 2011, driven by a 150% increase in AMRO, then plateaued. One percent fewer doses were distributed in 2015 than in 2011. Twenty-three countries were above the hurdle rate in 2015, compared to 15 in 2004, but distribution was highly uneven in and across all WHO regions. Three WHO regions (AMRO, EURO and WPRO) accounted for about 95% of doses distributed. But in EURO and WPRO, distribution rates in 2015 were only marginally higher than in 2004, and in EURO there was an overall downward trend in dose distribution. The vast majority of countries cannot meet the 2003WHA coverage targets and are inadequately prepared for a global influenza pandemic. With only 5% of influenza vaccine doses being distributed to 50% of the world's population, there is urgency to redress the gross inequities in disease prevention and in pandemic preparedness. The 2003WHA resolution must be reviewed and revised and a call issued for the renewed commitment of Member States to influenza vaccination coverage targets. Copyright © 2017. Published by Elsevier Ltd.
Evaluation of Larynx-Sparing Techniques With IMRT When Treating the Head and Neck
DOE Office of Scientific and Technical Information (OSTI.GOV)
Webster, Gareth J.; Rowbottom, Carl G.; Ho, Kean F.
2008-10-01
Purpose: Concern exists that widespread implementation of whole-field intensity-modulated radiotherapy (IMRT) for the treatment of head-and-neck cancer has resulted in increased levels of dysphagia relative to those seen with conventional planning. Other investigators have suggested an alternative junctioned-IMRT (J-IMRT) method, which matches an IMRT plan to a centrally blocked neck field to restrict the laryngeal dose and reduce dysphagia. The effect on target coverage and sparing of organs at risk, including laryngeal sparing, in the optimization was evaluated and compared with that achieved using a J-IMRT technique. Methods and Materials: A total of 13 oropharyngeal cancer whole-field IMRT plans weremore » planned with and without including laryngeal sparing in the optimization. A comparison of the target coverage and sparing of organs at risk was made using the resulting dose-volume histograms and dose distribution. The nine plans with disease located superior to the level of the larynx were replanned using a series of J-IMRT techniques to compare the two laryngeal-sparing techniques. Results: An average mean larynx dose of 29.1 Gy was achieved if disease did not extend to the level of the larynx, with 38.8 Gy for disease extending inferiorly and close to the larynx (reduced from 46.2 and 47.7 Gy, respectively, without laryngeal sparing). Additional laryngeal sparing could be achieved with J-IMRT (mean dose 24.4 Gy), although often at the expense of significantly reduced coverage of the target volume and with no improvement to other areas of the IMRT plan. Conclusion: The benefits of J-IMRT can be achieved with whole-field IMRT if laryngeal sparing is incorporated into the class solution. Inclusion of laryngeal sparing had no effect on other parameters in the plan.« less
Gao, Min; Li, Qilin; Ning, Zhonghua; Gu, Wendong; Huang, Jin; Mu, Jinming; Pei, Honglei
2016-01-01
To compare and analyze the dosimetric characteristics of volumetric modulated arc therapy (VMAT) vs step-shoot intensity-modulated radiation therapy (sIMRT) for upper thoracic and cervical esophageal carcinoma. Single-arc VMAT (VMAT1), dual-arc VMAT (VMAT2), and 7-field sIMRT plans were designed for 30 patients with upper thoracic or cervical esophageal carcinoma. Planning target volume (PTV) was prescribed to 50.4Gy in 28 fractions, and PTV1 was prescribed to 60Gy in 28 fractions. The parameters evaluated included dose homogeneity and conformality, dose to organs at risk (OARs), and delivery efficiency. (1) In comparison to sIMRT, VMAT provided a systematic improvement in PTV1 coverage. The homogeneity index of VMAT1 was better than that of VMAT2. There were no significant differences among sIMRT, VMAT1, and VMAT2 in PTV coverage. (2) VMAT1 and VMAT2 reduced the maximum dose of spinal cord as compared with sIMRT (p < 0.05). The rest dose-volume characteristics of OARs were similar. (3) Monitor units of VMAT2 and VMAT1 were more than sIMRT. However, the treatment time of VMAT1, VMAT2, and sIMRT was (2.0 ± 0.2), (2.8 ± 0.3), and (9.8 ± 0.8) minutes, respectively. VMAT1 was the fastest, and the difference was statistically significant. In the treatment of upper thoracic and cervical esophageal carcinoma by the AXESSE linac, compared with 7-field sIMRT, VMAT showed better PTV1 coverage and superior spinal cord sparing. Single-arc VMAT had similar target volume coverage and the sparing of OAR to dual-arc VMAT, with shortest treatment time and highest treatment efficiency in the 3 kinds of plans. Copyright © 2016 American Association of Medical Dosimetrists. Published by Elsevier Inc. All rights reserved.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Gao, Min; Li, Qilin; Ning, Zhonghua
2016-07-01
To compare and analyze the dosimetric characteristics of volumetric modulated arc therapy (VMAT) vs step-shoot intensity-modulated radiation therapy (sIMRT) for upper thoracic and cervical esophageal carcinoma. Single-arc VMAT (VMAT1), dual-arc VMAT (VMAT2), and 7-field sIMRT plans were designed for 30 patients with upper thoracic or cervical esophageal carcinoma. Planning target volume (PTV) was prescribed to 50.4 Gy in 28 fractions, and PTV1 was prescribed to 60 Gy in 28 fractions. The parameters evaluated included dose homogeneity and conformality, dose to organs at risk (OARs), and delivery efficiency. (1) In comparison to sIMRT, VMAT provided a systematic improvement in PTV1 coverage.more » The homogeneity index of VMAT1 was better than that of VMAT2. There were no significant differences among sIMRT, VMAT1, and VMAT2 in PTV coverage. (2) VMAT1 and VMAT2 reduced the maximum dose of spinal cord as compared with sIMRT (p < 0.05). The rest dose-volume characteristics of OARs were similar. (3) Monitor units of VMAT2 and VMAT1 were more than sIMRT. However, the treatment time of VMAT1, VMAT2, and sIMRT was (2.0 ± 0.2), (2.8 ± 0.3), and (9.8 ± 0.8) minutes, respectively. VMAT1 was the fastest, and the difference was statistically significant. In the treatment of upper thoracic and cervical esophageal carcinoma by the AXESSE linac, compared with 7-field sIMRT, VMAT showed better PTV1 coverage and superior spinal cord sparing. Single-arc VMAT had similar target volume coverage and the sparing of OAR to dual-arc VMAT, with shortest treatment time and highest treatment efficiency in the 3 kinds of plans.« less
ERIC Educational Resources Information Center
Moss, Nancy
1990-01-01
As the shrinking pool of applicants forces colleges to adapt new approaches to recruiting, media campaigns are emerging as an effective way to send key messages to target audiences. Media relations can lend credibility (news coverage is considered more credible than advertising); save money; reach targeted areas; and communicate key themes. (MLW)
SU-F-T-392: Superior Brainstem and Cochlea Sparing with VMAT for Glioblastoma Multiforme
DOE Office of Scientific and Technical Information (OSTI.GOV)
Briere, TM; McAleer, MF; Levy, LB
Purpose: Volumetric arc therapy (VMAT) can provide similar target coverage and normal tissue sparing as IMRT but with shorter treatment times. At our institution VMAT was adopted for the treatment glioblastoma multiforme (GBM) after a small number of test plans demonstrated its non-inferiority. In this study, we compare actual clinical treatment plans for a larger cohort of patients treated with either VMAT or IMRT. Methods: 90 GBM patients were included in this study, 45 treated with IMRT and 45 with VMAT. All planning target volumes (PTVs) were prescribed a dose of 50 Gy, with a simultaneous integrated boost to 60more » Gy. Most IMRT plans used 5 non-coplanar beams, while most VMAT plans used 2 coplanar beams. Statistical analysis was performed using Fisher’s exact test or the Wilcoxon-Mann-Whitney rank sum test. Included in the analysis were patient and treatment characteristics as well as the doses to the target volumes and organs at risk. Results: Treatment times for the VMAT plans were reduced by 5 minutes compared with IMRT. The PTV coverage was similar, with at least 95% covered for all plans, while the median boost PTV dose differed by 0.1 Gy between the IMRT and VMAT cohorts. The doses to the brain, optic chiasm, optic nerves and eyes were not significantly different. The mean dose to the brainstem, however, was 9.4 Gy less with VMAT (p<0.001). The dose to the ipsilateral and contralateral cochleae were respectively 19.7 and 9.5 Gy less (p<0.001). Conclusion: Comparison of clinical treatment plans for separate IMRT and VMAT cohorts demonstrates that VMAT can save substantial treatment time while providing similar target coverage and superior sparing of the brainstem and cochleae. To our knowledge this is the first study to demonstrate this benefit of VMAT in the management of GBM.« less
Lovelock, D Michael; Messineo, Alessandra P; Cox, Brett W; Kollmeier, Marisa A; Zelefsky, Michael J
2015-03-01
To compare the potential benefits of continuous monitoring of prostate position and intervention (CMI) using 2-mm displacement thresholds during stereotactic body radiation therapy (SBRT) treatment to those of a conventional image-guided procedure involving single localization prior to treatment. Eighty-nine patients accrued to a prostate SBRT dose escalation protocol were implanted with radiofrequency transponder beacons. The planning target volume (PTV) margin was 5 mm in all directions, except for 3 mm in the posterior direction. The prostate was kept within 2 mm of its planned position by the therapists halting dose delivery and, if necessary, correcting the couch position. We computed the number, type, and time required for interventions and where the prostate would have been during dose delivery had there been, instead, a single image-guided setup procedure prior to each treatment. Distributions of prostate displacements were computed as a function of time. After the initial setup, 1.7 interventions per fraction were required, with a concomitant increase in time for dose delivery of approximately 65 seconds. Small systematic drifts in prostate position in the posterior and inferior directions were observed in the study patients. Without CMI, intrafractional motion would have resulted in approximately 10% of patients having a delivered dose that did not meet our clinical coverage requirement, that is, a PTV D95 of >90%. The posterior PTV margin required for 95% of the dose to be delivered with the target positioned within the PTV was computed as a function of time. The margin necessary was found to increase by 2 mm every 5 minutes, starting from the time of the imaging procedure. CMI using a tight 2-mm displacement threshold was not only feasible but was found to deliver superior PTV coverage compared with the conventional image-guided procedure in the SBRT setting. Copyright © 2015 Elsevier Inc. All rights reserved.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Lovelock, D. Michael, E-mail: lovelocm@mskcc.org; Messineo, Alessandra P.; Cox, Brett W.
2015-03-01
Purpose: To compare the potential benefits of continuous monitoring of prostate position and intervention (CMI) using 2-mm displacement thresholds during stereotactic body radiation therapy (SBRT) treatment to those of a conventional image-guided procedure involving single localization prior to treatment. Methods and Materials: Eighty-nine patients accrued to a prostate SBRT dose escalation protocol were implanted with radiofrequency transponder beacons. The planning target volume (PTV) margin was 5 mm in all directions, except for 3 mm in the posterior direction. The prostate was kept within 2 mm of its planned position by the therapists halting dose delivery and, if necessary, correcting themore » couch position. We computed the number, type, and time required for interventions and where the prostate would have been during dose delivery had there been, instead, a single image-guided setup procedure prior to each treatment. Distributions of prostate displacements were computed as a function of time. Results: After the initial setup, 1.7 interventions per fraction were required, with a concomitant increase in time for dose delivery of approximately 65 seconds. Small systematic drifts in prostate position in the posterior and inferior directions were observed in the study patients. Without CMI, intrafractional motion would have resulted in approximately 10% of patients having a delivered dose that did not meet our clinical coverage requirement, that is, a PTV D95 of >90%. The posterior PTV margin required for 95% of the dose to be delivered with the target positioned within the PTV was computed as a function of time. The margin necessary was found to increase by 2 mm every 5 minutes, starting from the time of the imaging procedure. Conclusions: CMI using a tight 2-mm displacement threshold was not only feasible but was found to deliver superior PTV coverage compared with the conventional image-guided procedure in the SBRT setting.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Sivakumar, R; Janardhan, N; Bhavani, P
Purpose: To compare the plan quality and performance of Simultaneous Integrated Boost (SIB) Treatment plan between Seven field (7F) and Nine field(9F) Intensity Modulated Radiotherapies and Single Arc (SA) and Dual Arc (DA) Volumetric Modulated Arc Therapy( VMAT). Methods: Retrospective planning study of 16 patients treated in Elekta Synergy Platform (mlci2) by 9F-IMRT were replanned with 7F-IMRT, Single Arc VMAT and Dual Arc VMAT using CMS, Monaco Treatment Planning System (TPS) with Monte Carlo simulation. Target delineation done as per Radiation Therapy Oncology Protocols (RTOG 0225&0615). Dose Prescribed as 70Gy to Planning Target Volumes (PTV70) and 61Gy to PTV61 inmore » 33 fraction as a SIB technique. Conformity Index(CI), Homogeneity Index(HI) were used as analysis parameter for Target Volumes as well as Mean dose and Max dose for Organ at Risk(OAR,s).Treatment Delivery Time(min), Monitor unit per fraction (MU/fraction), Patient specific quality assurance were also analysed. Results: A Poor dose coverage and Conformity index (CI) was observed in PTV70 by 7F-IMRT among other techniques. SA-VMAT achieved poor dose coverage in PTV61. No statistical significance difference observed in OAR,s except Spinal cord (P= 0.03) and Right optic nerve (P=0.03). DA-VMAT achieved superior target coverage, higher CI (P =0.02) and Better HI (P=0.03) for PTV70 other techniques (7F-IMRT/9F-IMRT/SA-VMAT). A better dose spare for Parotid glands and spinal cord were seen in DA-VMAT. The average treatment delivery time were 5.82mins, 6.72mins, 3.24mins, 4.3mins for 7F-IMRT, 9F-IMRT, SA-VMAT and DA-VMAT respectively. Significance difference Observed in MU/fr (P <0.001) and Patient quality assurance pass rate were >95% (Gamma analysis (Γ3mm, 3%). Conclusion: DA-VAMT showed better target dose coverage and achieved better or equal performance in sparing OARs among other techniques. SA-VMAT offered least Treatment Time than other techniques but achieved poor target coverage. DA-VMAT offered shorter delivery time than 7F-IMRT and 9F-IMRT without compromising the plan quality.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Hepel, Jaroslaw T.; Department of Radiation Oncology, Brown University, Rhode Island Hospital, Providence, RI; Evans, Suzanne B.
2009-06-01
Purpose: To evaluate the accuracy of two clinical techniques for electron boost planning compared with computed tomography (CT)-based planning. Additionally, we evaluated the tumor bed characteristics at whole breast planning and boost planning. Methods and Materials: A total of 30 women underwent tumor bed boost planning within 2 weeks of completing whole breast radiotherapy using three planning techniques: scar-based planning, palpation/clinical-based planning, and CT-based planning. The plans were analyzed for dosimetric coverage of the CT-delineated tumor bed. The cavity visualization score was used to define the CT-delineated tumor bed as well or poorly defined. Results: Scar-based planning resulted in inferiormore » tumor bed coverage compared with CT-based planning, with the minimal dose received by 90% of the target volume >90% in 53% and a geographic miss in 53%. The results of palpation/clinical-based planning were significantly better: 87% and 10% for the minimal dose received by 90% of the target volume >90% and geographic miss, respectively. Of the 30 tumor beds, 16 were poorly defined by the cavity visualization score. Of these 16, 8 were well demarcated by the surgical clips. The evaluation of the 22 well-defined tumor beds revealed similar results. A comparison of the tumor bed volume from the initial planning CT scan to the boost planning CT scan revealed a decrease in size in 77% of cases. The mean decrease in volume was 52%. Conclusion: The results of our study have shown that CT-based planning allows for optimal tumor bed coverage compared with clinical and scar-based approaches. However, in the setting of a poorly visualized cavity on CT without surgical clips, palpation/clinical-based planning can help delineate the appropriate target volumes and is superior to scar-based planning. CT simulation at boost planning could allow for a reduction in the boost volumes.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Bosarge, Christina L., E-mail: cbosarge@umail.iu.edu; Ewing, Marvene M.; DesRosiers, Colleen M.
To demonstrate the dosimetric advantages and disadvantages of standard anteroposterior-posteroanterior (S-AP/PA{sub AAA}), inverse-planned AP/PA (IP-AP/PA) and volumetry-modulated arc (VMAT) radiotherapies in the treatment of children undergoing whole-lung irradiation. Each technique was evaluated by means of target coverage and normal tissue sparing, including data regarding low doses. A historical approach with and without tissue heterogeneity corrections is also demonstrated. Computed tomography (CT) scans of 10 children scanned from the neck to the reproductive organs were used. For each scan, 6 plans were created: (1) S-AP/PA{sub AAA} using the anisotropic analytical algorithm (AAA), (2) IP-AP/PA, (3) VMAT, (4) S-AP/PA{sub NONE} without heterogeneitymore » corrections, (5) S-AP/PA{sub PB} using the Pencil-Beam algorithm and enforcing monitor units from technique 4, and (6) S-AP/PA{sub AAA[FM]} using AAA and forcing fixed monitor units. The first 3 plans compare modern methods and were evaluated based on target coverage and normal tissue sparing. Body maximum and lower body doses (50% and 30%) were also analyzed. Plans 4 to 6 provide a historic view on the progression of heterogeneity algorithms and elucidate what was actually delivered in the past. Averages of each comparison parameter were calculated for all techniques. The S-AP/PA{sub AAA} technique resulted in superior target coverage but had the highest maximum dose to every normal tissue structure. The IP-AP/PA technique provided the lowest dose to the esophagus, stomach, and lower body doses. VMAT excelled at body maximum dose and maximum doses to the heart, spine, and spleen, but resulted in the highest dose in the 30% body range. It was, however, superior to the S-AP/PA{sub AAA} approach in the 50% range. Each approach has strengths and weaknesses thus associated. Techniques may be selected on a case-by-case basis and by physician preference of target coverage vs normal tissue sparing.« less
Abuya, Timothy O.; Fegan, Greg; Amin, Abdinasir A.; Akhwale, Willis S.; Noor, Abdisalan M.; Snow, Robert W.; Marsh, Vicki
2010-01-01
Background Private medicine retailers (PMRs) are key partners in the home management of fevers in many settings. Current evidence on effectiveness for PMR interventions at scale is limited. This study presents evaluation findings of two different programs implemented at moderate scale targeting PMRs for malaria control in the Kisii and Kwale districts of Kenya. Key components of this evaluation were measurement of program performance, including coverage, PMR knowledge, practices, and utilization based on spatial analysis. Methodology/Principal Findings The study utilized mixed quantitative methods including retail audits and surrogate client surveys based on post-intervention cross-sectional surveys in intervention and control areas and mapping of intervention outlets. There was a large and significant impact on PMR knowledge and practices of the program in Kisii, with 60.5% of trained PMRs selling amodiaquine medicines in adequate doses compared to 2.8% of untrained ones (OR; 53.5: 95% CI 6.7, 428.3), a program coverage of 69.7% targeted outlets, and a potential utilization of about 30,000 children under five. The evaluation in Kwale also indicates a significant impact with 18.8% and 2.3% intervention and control PMRs selling amodiaquine with correct advice, respectively (OR; 9.4: 95% CI 1.1, 83.7), a program coverage of 25.3% targeted outlets, and a potential utilization of about 48,000 children under five. A provisional benchmark of 7.5 km was a reasonable threshold distance for households to access PMR services. Conclusions/Significance This evaluation show that PMR interventions operationalized in the district level settings are likely to impact PMR knowledge and practices and lead to increased coverage of appropriate treatment to target populations. There is value of evaluating different dimensions of public health programs, including quality, spatial access, and implementation practice. This approach strengthens the potential contribution of pragmatic study designs to evaluating public health programs in the real world. PMID:20126620
DOE Office of Scientific and Technical Information (OSTI.GOV)
Calvo, Juan Francisco, E-mail: jfcdrr@gmail.com; San José, Sol; Garrido, LLuís
2013-10-01
To introduce an approach for online adaptive replanning (i.e., dose-guided radiosurgery) in frameless stereotactic radiosurgery, when a 6-dimensional (6D) robotic couch is not available in the linear accelerator (linac). Cranial radiosurgical treatments are planned in our department using intensity-modulated technique. Patients are immobilized using thermoplastic mask. A cone-beam computed tomography (CBCT) scan is acquired after the initial laser-based patient setup (CBCT{sub setup}). The online adaptive replanning procedure we propose consists of a 6D registration-based mapping of the reference plan onto actual CBCT{sub setup}, followed by a reoptimization of the beam fluences (“6D plan”) to achieve similar dosage as originally wasmore » intended, while the patient is lying in the linac couch and the original beam arrangement is kept. The goodness of the online adaptive method proposed was retrospectively analyzed for 16 patients with 35 targets treated with CBCT-based frameless intensity modulated technique. Simulation of reference plan onto actual CBCT{sub setup}, according to the 4 degrees of freedom, supported by linac couch was also generated for each case (4D plan). Target coverage (D99%) and conformity index values of 6D and 4D plans were compared with the corresponding values of the reference plans. Although the 4D-based approach does not always assure the target coverage (D99% between 72% and 103%), the proposed online adaptive method gave a perfect coverage in all cases analyzed as well as a similar conformity index value as was planned. Dose-guided radiosurgery approach is effective to assure the dose coverage and conformity of an intracranial target volume, avoiding resetting the patient inside the mask in a “trial and error” way so as to remove the pitch and roll errors when a robotic table is not available.« less
Expansion of seasonal influenza vaccination in the Americas
Ropero-Álvarez, Alba María; Kurtis, Hannah J; Danovaro-Holliday, M Carolina; Ruiz-Matus, Cuauhtémoc; Andrus, Jon K
2009-01-01
Background Seasonal influenza is a viral disease whose annual epidemics are estimated to cause three to five million cases of severe illness and 250,000 to 500,000 deaths worldwide. Vaccination is the main strategy for primary prevention. Methods To assess the status of influenza vaccination in the Americas, influenza vaccination data reported to the Pan American Health Organization (PAHO) through 2008 were analyzed. Results Thirty-five countries and territories administered influenza vaccine in their public health sector, compared to 13 countries in 2004. Targeted risk groups varied. Sixteen countries reported coverage among older adults, ranging from 21% to 100%; coverage data were not available for most countries and targeted populations. Some tropical countries used the Northern Hemisphere vaccine formulation and others used the Southern Hemisphere vaccine formulation. In 2008, approximately 166.3 million doses of seasonal influenza vaccine were purchased in the Americas; 30 of 35 countries procured their vaccine through PAHO's Revolving Fund. Conclusion Since 2004 there has been rapid uptake of seasonal influenza vaccine in the Americas. Challenges to fully implement influenza vaccination remain, including difficulties measuring coverage rates, variable vaccine uptake, and limited surveillance and effectiveness data to guide decisions regarding vaccine formulation and timing, especially in tropical countries. PMID:19778430
State of equity: childhood immunization in the World Health Organization African Region.
Casey, Rebecca Mary; Hampton, Lee McCalla; Anya, Blanche-Philomene Melanga; Gacic-Dobo, Marta; Diallo, Mamadou Saliou; Wallace, Aaron Stuart
2017-01-01
In 2010, the Global Vaccine Action Plan called on all countries to reach and sustain 90% national coverage and 80% coverage in all districts for the third dose of diphtheria-tetanus-pertussis vaccine (DTP3) by 2015 and for all vaccines in national immunization schedules by 2020. The aims of this study are to analyze recent trends in national vaccination coverage in the World Health Organization African Region andto assess how these trends differ by country income category. We compared national vaccination coverage estimates for DTP3 and the first dose of measles-containing vaccine (MCV) obtained from the World Health Organization (WHO)/United Nations Children's Fund (UNICEF) joint estimates of national immunization coverage for all African Region countries. Using United Nations (UN) population estimates of surviving infants and country income category for the corresponding year, we calculated population-weighted average vaccination coverage by country income category (i.e., low, lower middle, and upper middle-income) for the years 2000, 2005, 2010 and 2015. DTP3 coverage in the African Region increased from 52% in 2000 to 76% in 2015,and MCV1 coverage increased from 53% to 74% during the same period, but with considerable differences among countries. Thirty-six African Region countries were low income in 2000 with an average DTP3 coverage of 50% while 26 were low income in 2015 with an average coverage of 80%. Five countries were lower middle-income in 2000 with an average DTP3 coverage of 84% while 12 were lower middle-income in 2015 with an average coverage of 69%. Five countries were upper middle-income in 2000 with an average DTP3 coverage of 73% and eight were upper middle-income in 2015 with an average coverage of 76%. Disparities in vaccination coverage by country persist in the African Region, with countries that were lower middle-income having the lowest coverage on average in 2015. Monitoring and addressing these disparities is essential for meeting global immunization targets.
Deardorff, Katrina V; Rubin Means, Arianna; Ásbjörnsdóttir, Kristjana H; Walson, Judd
2018-02-01
Community-based public health campaigns, such as those used in mass deworming, vitamin A supplementation and child immunization programs, provide key healthcare interventions to targeted populations at scale. However, these programs often fall short of established coverage targets. The purpose of this systematic review was to evaluate the impact of strategies used to increase treatment coverage in community-based public health campaigns. We systematically searched CAB Direct, Embase, and PubMed archives for studies utilizing specific interventions to increase coverage of community-based distribution of drugs, vaccines, or other public health services. We identified 5,637 articles, from which 79 full texts were evaluated according to pre-defined inclusion and exclusion criteria. Twenty-eight articles met inclusion criteria and data were abstracted regarding strategy-specific changes in coverage from these sources. Strategies used to increase coverage included community-directed treatment (n = 6, pooled percent change in coverage: +26.2%), distributor incentives (n = 2, +25.3%), distribution along kinship networks (n = 1, +24.5%), intensified information, education, and communication activities (n = 8, +21.6%), fixed-point delivery (n = 1, +21.4%), door-to-door delivery (n = 1, +14.0%), integrated service distribution (n = 9, +12.7%), conversion from school- to community-based delivery (n = 3, +11.9%), and management by a non-governmental organization (n = 1, +5.8%). Strategies that target improving community member ownership of distribution appear to have a large impact on increasing treatment coverage. However, all strategies used to increase coverage successfully did so. These results may be useful to National Ministries, programs, and implementing partners in optimizing treatment coverage in community-based public health programs.
2018-01-01
Background Community-based public health campaigns, such as those used in mass deworming, vitamin A supplementation and child immunization programs, provide key healthcare interventions to targeted populations at scale. However, these programs often fall short of established coverage targets. The purpose of this systematic review was to evaluate the impact of strategies used to increase treatment coverage in community-based public health campaigns. Methodology/ principal findings We systematically searched CAB Direct, Embase, and PubMed archives for studies utilizing specific interventions to increase coverage of community-based distribution of drugs, vaccines, or other public health services. We identified 5,637 articles, from which 79 full texts were evaluated according to pre-defined inclusion and exclusion criteria. Twenty-eight articles met inclusion criteria and data were abstracted regarding strategy-specific changes in coverage from these sources. Strategies used to increase coverage included community-directed treatment (n = 6, pooled percent change in coverage: +26.2%), distributor incentives (n = 2, +25.3%), distribution along kinship networks (n = 1, +24.5%), intensified information, education, and communication activities (n = 8, +21.6%), fixed-point delivery (n = 1, +21.4%), door-to-door delivery (n = 1, +14.0%), integrated service distribution (n = 9, +12.7%), conversion from school- to community-based delivery (n = 3, +11.9%), and management by a non-governmental organization (n = 1, +5.8%). Conclusions/significance Strategies that target improving community member ownership of distribution appear to have a large impact on increasing treatment coverage. However, all strategies used to increase coverage successfully did so. These results may be useful to National Ministries, programs, and implementing partners in optimizing treatment coverage in community-based public health programs. PMID:29420534
Kan, Monica W K; Leung, Lucullus H T; Yu, Peter K N
2013-11-04
A new version of progressive resolution optimizer (PRO) with an option of air cavity correction has been implemented for RapidArc volumetric-modulated arc therapy (RA). The purpose of this study was to compare the performance of this new PRO with the use of air cavity correction option (PRO10_air) against the one without the use of the air cavity correction option (PRO10_no-air) for RapidArc planning in targets with low-density media of different sizes and complexities. The performance of PRO10_no-air and PRO10_air was initially compared using single-arc plans created for four different simple heterogeneous phantoms with virtual targets and organs at risk. Multiple-arc planning of 12 real patients having nasopharyngeal carcinomas (NPC) and ten patients having non-small cell lung cancer (NSCLC) were then performed using the above two options for further comparison. Dose calculations were performed using both the Acuros XB (AXB) algorithm with the dose to medium option and the analytical anisotropic algorithm (AAA). The effect of using intermediate dose option after the first optimization cycle in PRO10_air and PRO10_no-air was also investigated and compared. Plans were evaluated and compared using target dose coverage, critical organ sparing, conformity index, and dose homogeneity index. For NSCLC cases or cases for which large volumes of low-density media were present in or adjacent to the target volume, the use of the air cavity correction option in PRO10 was shown to be beneficial. For NPC cases or cases for which small volumes of both low- and high-density media existed in the target volume, the use of air cavity correction in PRO10 did not improve the plan quality. Based on the AXB dose calculation results, the use of PRO10_air could produce up to 18% less coverage to the bony structures of the planning target volumes for NPC cases. When the intermediate dose option in PRO10 was used, there was negligible difference observed in plan quality between optimizations with and without using the air cavity correction option.
Reeder, Anthony I; Gray, Andrew R; Liley, J Ben; Scragg, Robert K R; McKenzie, Richard L; Stewart, Alistair W
2016-03-01
Clothing coverage is important for reducing skin cancer risk, but may also influence vitamin D sufficiency, so associated plausible predictors require investigation. Volunteers (18 to 85 years), with approximately equal numbers by sex and four ethnicity groups, were recruited in cities from two latitude bands: Auckland (36.9°S) and Dunedin (45.9°S). Baseline questionnaire, anthropometric and spectrophotometer skin colour data were collected and weather data obtained. Percent body coverage was calculated from eight week diary records. Potential independent predictors (unadjusted p < 0.25) were included in adjusted models. Participants (n = 506: Auckland n = 334, Dunedin n = 172; mean age 48.4 years) were 62.7% female and had a median body clothing coverage of 81.6% (IQR 9.3%). Dunedin was cooler, less windy and had lower UVI levels than Auckland. From the fully adjusted model, increased coverage occurred in non-summer months (despite adjusting for weather), among Dunedin residents and Asians (compared to Europeans), during the middle of the day, with a dose response effect observed for greater age. Reduced coverage was associated with Pacific ethnicity and greater time spent outdoors. Additionally, higher temperatures were associated with reduced coverage, whereas increased cloud cover and wind speed were associated with increased coverage. Although the only potentially modifiable factors associated with clothing coverage were the time period and time spent outdoors, knowledge of these and other associated factors is useful for the framing and targeting of health promotion messages to potentially influence clothing coverage, facilitate erythema avoidance and maintain vitamin D sufficiency.
Set-up uncertainties: online correction with X-ray volume imaging.
Kataria, Tejinder; Abhishek, Ashu; Chadha, Pranav; Nandigam, Janardhan
2011-01-01
To determine interfractional three-dimensional set-up errors using X-ray volumetric imaging (XVI). Between December 2007 and August 2009, 125 patients were taken up for image-guided radiotherapy using online XVI. After matching of reference and acquired volume view images, set-up errors in three translation directions were recorded and corrected online before treatment each day. Mean displacements, population systematic (Σ), and random (σ) errors were calculated and analyzed using SPSS (v16) software. Optimum clinical target volume (CTV) to planning target volume (PTV) margin was calculated using Van Herk's (2.5Σ + 0.7 σ) and Stroom's (2Σ + 0.7 σ) formula. Patients were grouped in 4 cohorts, namely brain, head and neck, thorax, and abdomen-pelvis. The mean vector displacement recorded were 0.18 cm, 0.15 cm, 0.36 cm, and 0.35 cm for brain, head and neck, thorax, and abdomen-pelvis, respectively. Analysis of individual mean set-up errors revealed good agreement with the proposed 0.3 cm isotropic margins for brain and 0.5 cm isotropic margins for head-neck. Similarly, 0.5 cm circumferential and 1 cm craniocaudal proposed margins were in agreement with thorax and abdomen-pelvic cases. The calculated mean displacements were well within CTV-PTV margin estimates of Van Herk (90% population coverage to minimum 95% prescribed dose) and Stroom (99% target volume coverage by 95% prescribed dose). Employing these individualized margins in a particular cohort ensure comparable target coverage as described in literature, which is further improved if XVI-aided set-up error detection and correction is used before treatment.
To close the childhood immunization gap, we need a richer understanding of parents' decision-making.
Corben, Paul; Leask, Julie
2016-12-01
Vaccination is widely acknowledged as one of the most successful public health interventions globally and in most high-income countries childhood vaccination coverage rates are moderately high. Yet in many instances, immunisation rates remain below aspirational targets and have shown only modest progress toward those targets in recent years, despite concerted efforts to improve uptake. In part, coverage rates reflect individual parents' vaccination attitudes and decisions and, because vaccination decision-making is complex and context-specific, it remains challenging at individual and community levels to assist parents to make positive decisions. Consequently, in the search for opportunities to improve immunisation coverage, there has been a renewed research focus on parents' decision-making. This review provides an overview of the literature surrounding parents' vaccination decision-making, offering suggestions for where efforts to increase vaccination coverage should be targeted and identifying areas for further research.
Treuer, Harald; Hoevels, Moritz; Luyken, Klaus; Visser-Vandewalle, Veerle; Wirths, Jochen; Kocher, Martin; Ruge, Maximilian
2015-06-01
Stereotactic radiosurgery with an adapted linear accelerator (linac-SRS) is an established therapy option for brain metastases, benign brain tumors, and arteriovenous malformations. We intended to investigate whether the dosimetric quality of treatment plans achieved with a CyberKnife (CK) is at least equivalent to that for linac-SRS with circular or micromultileaf collimators (microMLC). A random sample of 16 patients with 23 target volumes, previously treated with linac-SRS, was replanned with CK. Planning constraints were identical dose prescription and clinical applicability. In all cases uniform optimization scripts and inverse planning objectives were used. Plans were compared with respect to coverage, minimal dose within target volume, conformity index, and volume of brain tissue irradiated with ≥ 10 Gy. Generating the CK plan was unproblematic with simple optimization scripts in all cases. With the CK plans, coverage, minimal target volume dosage, and conformity index were significantly better, while no significant improvement could be shown regarding the 10 Gy volume. Multiobjective comparison for the irradiated target volumes was superior in the CK plan in 20 out of 23 cases and equivalent in 3 out of 23 cases. Multiobjective comparison for the treated patients was superior in the CK plan in all 16 cases. The results clearly demonstrate the superiority of the irradiation plan for CK compared to classical linac-SRS with circular collimators and microMLC. In particular, the average minimal target volume dose per patient, increased by 1.9 Gy, and at the same time a 14% better conformation index seems to be an improvement with clinical relevance.
Ren, Juan; Yuan, Wei; Wang, Ruihua; Wang, Qiuping; Li, Yi; Xue, Chaofan; Yan, Yanli; Ma, Xiaowei; Tan, Li; Liu, Zi
2016-01-01
Objective The purpose of this study was to comprehensively compare the 3-dimensional (3D) magnetic resonance imaging (MRI)-guided and conventional 2-dimensional (2D) point A-based intracavitary brachytherapy (BT) planning for cervical cancer with regard to target dose coverage and dosages to adjacent organs-at risk (OARs). Methods A total of 79 patients with cervical cancer were enrolled to receive 2D point A-based BT planning and then immediately to receive 3D planning between October 2011 and April 2013 at the First Hospital Affiliated to Xi’an Jiao Tong University (Xi’an, China). The dose-volume histogram (DVH) parameters for gross tumor volume (GTV), high-risk clinical target volume (HR-CTV), intermediate-risk clinical target volume (IR-CTV) and OARs were compared between the 2D and 3D planning. Results In small tumors, there was no significant difference in most of the DVHs between 2D and 3D planning (all p>0.05). While in big tumors, 3D BT planning significantly increased the DVHs for most of the GTV, HR-CTV and IR-CTV, and some OARs compared with 2D planning (all P<0.05). In 3D planning, DVHs for GTV, HR-CTV, IR-CTV and some OARs were significantly higher in big tumors than in small tumors (all p<0.05). In contrast, in 2D planning, DVHs for almost all of the HR-CTV and IR-CTV were significantly lower in big tumors (all p<0.05). In eccentric tumors, 3D planning significantly increased dose coverage but decreased dosages to OARs compared with 2D planning (p<0.05). In tumors invading adjacent tissues, the target dose coverage in 3D planning was generally significantly higher than in 2D planning (P<0.05); the dosages to the adjacent rectum and bladder were significantly higher but those to sigmoid colon were lower in 3D planning (all P<0.05). Conclusions 3D MRI image-guided BT planning exhibits advantages over 2D planning in a complex way, generally showing advantages for the treatment of cervical cancer except small tumors. PMID:27611853
Mallari, Neil Aldrin D; Collar, Nigel J; McGowan, Philip J K; Marsden, Stuart J
2016-04-01
Aichi Target 11 of the Convention on Biological Diversity urges, inter alia, that nations protect at least 17 % of their land, and that protection is effective and targets areas of importance for biodiversity. Five years before reporting on Aichi targets is due, we assessed the Philippines' current protected area system for biodiversity coverage, appropriateness of management regimes and capacity to deliver protection. Although protected estate already covers 11 % of the Philippines' land area, 64 % of its key biodiversity areas (KBAs) remain unprotected. Few protected areas have appropriate management and governance infrastructures, funding streams, management plans and capacity, and a serious mismatch exists between protected area land zonation regimes and conservation needs of key species. For the Philippines to meet the biodiversity coverage and management effectiveness elements of Aichi Target 11, protected area and KBA boundaries should be aligned, management systems reformed to pursue biodiversity-led targets and effective management capacity created.
Tyler, Madelaine K
2016-01-08
This study quantified the interplay and gradient effects on GTV dose coverage for 3D CRT, dMLC IMRT, and VMAT SABR treatments for target amplitudes of 5-30 mm using 3DVH v3.1 software incorporating 4D Respiratory MotionSim (4D RMS) module. For clinically relevant motion periods (5 s), the interplay effect was small, with deviations in the minimum dose covering the target volume (D99%) of less than ± 2.5% for target amplitudes up to 30 mm. Increasing the period to 60 s resulted in interplay effects of up to ± 15.0% on target D99% dose coverage. The gradient effect introduced by target motion resulted in deviations of up to ± 3.5% in D99% target dose coverage. VMAT treatments showed the largest deviation in dose metrics, which was attributed to the long delivery times in comparison to dMLC IMRT. Retrospective patient analysis indicated minimal interplay and gradient effects for patients treated with dMLC IMRT at the NCCI.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Ge, Y; OBrien, R; Shieh, C
2014-06-15
Purpose: Intrafraction tumor deformation limits targeting accuracy in radiotherapy and cannot be adapted to by current motion management techniques. This study simulated intrafractional treatment adaptation to tumor deformations using a dynamic Multi-Leaf Collimator (DMLC) tracking system during Intensity-modulated radiation therapy (IMRT) treatment for the first time. Methods: The DMLC tracking system was developed to adapt to the intrafraction tumor deformation by warping the planned beam aperture guided by the calculated deformation vector field (DVF) obtained from deformable image registration (DIR) at the time of treatment delivery. Seven single phantom deformation images up to 10.4 mm deformation and eight tumor systemmore » phantom deformation images up to 21.5 mm deformation were acquired and used in tracking simulation. The intrafraction adaptation was simulated at the DMLC tracking software platform, which was able to communicate with the image registration software, reshape the instantaneous IMRT field aperture and log the delivered MLC fields.The deformation adaptation accuracy was evaluated by a geometric target coverage metric defined as the sum of the area incorrectly outside and inside the reference aperture. The incremental deformations were arbitrarily determined to take place equally over the delivery interval. The geometric target coverage of delivery with deformation adaptation was compared against the delivery without adaptation. Results: Intrafraction deformation adaptation during dynamic IMRT plan delivery was simulated for single and system deformable phantoms. For the two particular delivery situations, over the treatment course, deformation adaptation improved the target coverage by 89% for single target deformation and 79% for tumor system deformation compared with no-tracking delivery. Conclusion: This work demonstrated the principle of real-time tumor deformation tracking using a DMLC. This is the first step towards the development of an image-guided radiotherapy system to treat deforming tumors in real-time. The authors acknowledge funding support from the Australian NHMRC Australia Fellowship, Cure Cancer Australia Foundation, NHMRC Project Grant APP1042375 and US NIH/NCI R01CA93626.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Zhang, JY; Hong, DL
Purpose: The purpose of this study is to investigate the patient set-up error and interfraction target coverage in cervical cancer using image-guided adaptive radiotherapy (IGART) with cone-beam computed tomography (CBCT). Methods: Twenty cervical cancer patients undergoing intensity modulated radiotherapy (IMRT) were randomly selected. All patients were matched to the isocenter using laser with the skin markers. Three dimensional CBCT projections were acquired by the Varian Truebeam treatment system. Set-up errors were evaluated by radiation oncologists, after CBCT correction. The clinical target volume (CTV) was delineated on each CBCT, and the planning target volume (PTV) coverage of each CBCT-CTVs was analyzed.more » Results: A total of 152 CBCT scans were acquired from twenty cervical cancer patients, the mean set-up errors in the longitudinal, vertical, and lateral direction were 3.57, 2.74 and 2.5mm respectively, without CBCT corrections. After corrections, these were decreased to 1.83, 1.44 and 0.97mm. For the target coverage, CBCT-CTV coverage without CBCT correction was 94% (143/152), and 98% (149/152) with correction. Conclusion: Use of CBCT verfication to measure patient setup errors could be applied to improve the treatment accuracy. In addition, the set-up error corrections significantly improve the CTV coverage for cervical cancer patients.« less
Characterizing Health Information for Different Target Audiences.
Sun, Yueping; Hou, Zhen; Hou, Li; Li, Jiao
2015-01-01
Different groups of audiences in health care: health professionals and health consumers, each have different information needs. Health monographs targeting different audiences are created by leveraging readers' background knowledge. The NCI's Physician Data Query (PDQ®) Cancer Information Summaries provide parallel cancer information and education resources with different target audiences. In this paper, we used targeted audience-specific cancer information PDQs to measure characteristic differences on the element level between audiences. In addition, we compared vocabulary coverage. Results show a significant difference between the professional and patient version of cancer monographs in both content organization and vocabulary. This study provides a new view to assess targeted audience-specific health information, and helps editors to improve the quality and readability of health information.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Kozak, Kevin R.; Adams, Judith; Krejcarek, Stephanie J.
Purpose: We compared tumor and normal tissue dosimetry of proton radiation therapy with intensity-modulated radiation therapy (IMRT) for pediatric parameningeal rhabdomyosarcomas (PRMS). Methods and Materials: To quantify dosimetric differences between contemporary proton and photon treatment for pediatric PRMS, proton beam plans were compared with IMRT plans. Ten patients treated with proton radiation therapy at Massachusetts General Hospital had IMRT plans generated. To facilitate dosimetric comparisons, clinical target volumes and normal tissue volumes were held constant. Plans were optimized for target volume coverage and normal tissue sparing. Results: Proton and IMRT plans provided acceptable and comparable target volume coverage, with atmore » least 99% of the CTV receiving 95% of the prescribed dose in all cases. Improved dose conformality provided by proton therapy resulted in significant sparing of all examined normal tissues except for ipsilateral cochlea and mastoid; ipsilateral parotid gland sparing was of borderline statistical significance (p = 0.05). More profound sparing of contralateral structures by protons resulted in greater dose asymmetry between ipsilateral and contralateral retina, optic nerves, cochlea, and mastoids; dose asymmetry between ipsilateral and contralateral parotids was of borderline statistical significance (p = 0.05). Conclusions: For pediatric PRMS, superior normal tissue sparing is achieved with proton radiation therapy compared with IMRT. Because of enhanced conformality, proton plans also demonstrate greater normal tissue dose distribution asymmetry. Longitudinal studies assessing the impact of proton radiotherapy and IMRT on normal tissue function and growth symmetry are necessary to define the clinical consequences of these differences.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Bossart, Elizabeth L., E-mail: EBossart@med.miami.edu; Stoyanova, Radka; Sandler, Kiri
2016-06-01
Purpose: To compare dosimetric characteristics with multiparametric magnetic resonance imaging–identified imaging tumor volume (gross tumor volume, GTV), prostate clinical target volume and planning target volume, and organs at risk (OARs) for 2 treatment techniques representing 2 arms of an institutional phase 3 randomized trial of hypofractionated external beam image guided highly targeted radiation therapy. Methods and Materials: Group 1 (n=20) patients were treated before the trial inception with the standard dose prescription. Each patient had an additional treatment plan generated per the experimental arm. A total of 40 treatment plans were compared (20 plans for each technique). Group 2 (n=15)more » consists of patients currently accrued to the hypofractionated external beam image guided highly targeted radiation therapy trial. Plans were created as per the treatment arm, with additional plans for 5 of the group 2 experimental arm with a 3-mm expansion in the imaging GTV. Results: For all plans in both patient groups, planning target volume coverage ranged from 95% to 100%; GTV coverage of 89.3 Gy for the experimental treatment plans ranged from 95.2% to 99.8%. For both groups 1 and 2, the percent volumes of rectum/anus and bladder receiving 40 Gy, 65 Gy, and 80 Gy were smaller in the experimental plans than in the standard plans. The percent volume at 1 Gy per fraction and 1.625 Gy per fraction were compared between the standard and the experimental arms, and these were found to be equivalent. Conclusions: The dose per fraction to the OARs can be made equal even when giving a large simultaneous integrated boost to the GTV. The data suggest that a GTV margin may be added without significant dose effects on the OARs.« less
Vaccination coverage among children in kindergarten--United States, 2009-10 school year.
2011-06-03
Healthy People 2020 objectives include maintaining vaccination coverage among children in kindergarten (IID-10) (1). The target is ≥95% vaccination coverage for the following vaccines: poliovirus; diphtheria and tetanus toxoids and acellular pertussis (DTP/DTaP/DT); measles, mumps, and rubella (MMR); hepatitis B (HepB); and varicella (1). Data from school assessment surveys are used to monitor vaccination coverage and vaccination exemption levels among children enrolled in kindergarten. This report summarizes data from school assessment surveys submitted to CDC by 48 federal immunization program grantees (including 47 states and the District of Columbia) for the 2009-10 school year to describe vaccination coverage and exemption rates (2). For that period, 17 grantees reported coverage of ?95% for four vaccines (poliovirus, DTP/DTaP/DT, MMR, and HepB) and four grantees reported coverage of ≥95% for 2 doses of varicella vaccine. Total exemption rates, including medical, religious, and philosophical exemptions, ranged from <1% to 6.2% across grantees, and 15 grantees reported exemption rates<1%. Survey methods for vaccination coverage and exemption rates varied among grantees, making comparisons difficult and limiting the use of school assessment surveys to report aggregate national rates. Further standardization of school assessment survey methods will generate comparable data between grantees to monitor and track progress in reaching national objectives, and allow development of best practice guidelines for grantees to more effectively use and report school coverage and exemption data. CDC will continue to monitor vaccination coverage and exemption levels and assist grantees in identification of local areas with low vaccination coverage or high exemption rates for further evaluation or intervention.
Comparing Treatment Plan in All Locations of Esophageal Cancer
Lin, Jang-Chun; Tsai, Jo-Ting; Chang, Chih-Chieh; Jen, Yee-Min; Li, Ming-Hsien; Liu, Wei-Hsiu
2015-01-01
Abstract The aim of this study was to compare treatment plans of volumetric modulated arc therapy (VMAT) with intensity-modulated radiotherapy (IMRT) for all esophageal cancer (EC) tumor locations. This retrospective study from July 2009 to June 2014 included 20 patients with EC who received definitive concurrent chemoradiotherapy with radiation doses >50.4 Gy. Version 9.2 of Pinnacle3 with SmartArc was used for treatment planning. Dosimetric quality was evaluated based on doses to several organs at risk, including the spinal cord, heart, and lung, over the same coverage of gross tumor volume. In upper thoracic EC, the IMRT treatment plan had a lower lung mean dose (P = 0.0126) and lung V5 (P = 0.0037) compared with VMAT; both techniques had similar coverage of the planning target volumes (PTVs) (P = 0.3575). In middle thoracic EC, a lower lung mean dose (P = 0.0010) and V5 (P = 0.0145), but higher lung V20 (P = 0.0034), spinal cord Dmax (P = 0.0262), and heart mean dose (P = 0.0054), were observed for IMRT compared with VMAT; IMRT provided better PTV coverage. Patients with lower thoracic ECs had a lower lung mean dose (P = 0.0469) and V5 (P = 0.0039), but higher spinal cord Dmax (P = 0.0301) and heart mean dose (P = 0.0020), with IMRT compared with VMAT. PTV coverage was similar (P = 0.0858) for the 2 techniques. IMRT provided a lower mean dose and lung V5 in upper thoracic EC compared with VMAT, but exhibited different advantages and disadvantages in patients with middle or lower thoracic ECs. Thus, choosing different techniques for different EC locations is warranted. PMID:25929910
Lin, Jang-Chun; Tsai, Jo-Ting; Chang, Chih-Chieh; Jen, Yee-Min; Li, Ming-Hsien; Liu, Wei-Hsiu
2015-05-01
The aim of this study was to compare treatment plans of volumetric modulated arc therapy (VMAT) with intensity-modulated radiotherapy (IMRT) for all esophageal cancer (EC) tumor locations.This retrospective study from July 2009 to June 2014 included 20 patients with EC who received definitive concurrent chemoradiotherapy with radiation doses >50.4 Gy. Version 9.2 of Pinnacle with SmartArc was used for treatment planning. Dosimetric quality was evaluated based on doses to several organs at risk, including the spinal cord, heart, and lung, over the same coverage of gross tumor volume.In upper thoracic EC, the IMRT treatment plan had a lower lung mean dose (P = 0.0126) and lung V5 (P = 0.0037) compared with VMAT; both techniques had similar coverage of the planning target volumes (PTVs) (P = 0.3575). In middle thoracic EC, a lower lung mean dose (P = 0.0010) and V5 (P = 0.0145), but higher lung V20 (P = 0.0034), spinal cord Dmax (P = 0.0262), and heart mean dose (P = 0.0054), were observed for IMRT compared with VMAT; IMRT provided better PTV coverage. Patients with lower thoracic ECs had a lower lung mean dose (P = 0.0469) and V5 (P = 0.0039), but higher spinal cord Dmax (P = 0.0301) and heart mean dose (P = 0.0020), with IMRT compared with VMAT. PTV coverage was similar (P = 0.0858) for the 2 techniques.IMRT provided a lower mean dose and lung V5 in upper thoracic EC compared with VMAT, but exhibited different advantages and disadvantages in patients with middle or lower thoracic ECs. Thus, choosing different techniques for different EC locations is warranted.
NASA Astrophysics Data System (ADS)
Feng, Wei; Ma, Ning; Zhu, Dan
2015-03-01
The improvement of methods for optical clearing agent prediction exerts an important impact on tissue optical clearing technique. The molecular dynamic simulation is one of the most convincing and simplest approaches to predict the optical clearing potential of agents by analyzing the hydrogen bonds, hydrogen bridges and hydrogen bridges type forming between agents and collagen. However, the above analysis methods still suffer from some problem such as analysis of cyclic molecule by reason of molecular conformation. In this study, a molecular effective coverage surface area based on the molecular dynamic simulation was proposed to predict the potential of optical clearing agents. Several typical cyclic molecules, fructose, glucose and chain molecules, sorbitol, xylitol were analyzed by calculating their molecular effective coverage surface area, hydrogen bonds, hydrogen bridges and hydrogen bridges type, respectively. In order to verify this analysis methods, in vitro skin samples optical clearing efficacy were measured after 25 min immersing in the solutions, fructose, glucose, sorbitol and xylitol at concentration of 3.5 M using 1951 USAF resolution test target. The experimental results show accordance with prediction of molecular effective coverage surface area. Further to compare molecular effective coverage surface area with other parameters, it can show that molecular effective coverage surface area has a better performance in predicting OCP of agents.
Evaluation of different strategies for magnetic particle functionalization with DNA aptamers.
Pérez-Ruiz, Elena; Lammertyn, Jeroen; Spasic, Dragana
2016-12-25
The optimal bio-functionalization of magnetic particles is essential for developing magnetic particle-based bioassays. Whereas functionalization with antibodies is generally well established, immobilization of DNA probes, such as aptamers, is not yet fully explored. In this work, four different types of commercially available magnetic particles, coated with streptavidin, maleimide or carboxyl groups, were evaluated for their surface coverage with aptamer bioreceptors, efficiency in capturing target protein and non-specific protein adsorption on their surface. A recently developed aptamer against the peanut allergen, Ara h 1 protein, was used as a model system. Conjugation of biotinylated Ara h 1 aptamer to the streptavidin particles led to the highest surface coverage, whereas the coverage of maleimide particles was 25% lower. Carboxylated particles appeared to be inadequate for DNA functionalization. Streptavidin particles also showed the greatest target capturing efficiency, comparable to the one of particles functionalized with anti-Ara h 1 antibody. The performance of streptavidin particles was additionally tested in a sandwich assay with the aptamer as a capture receptor on the particle surface. While the limit of detection obtained was comparable to the same assay system with antibody as capture receptor, it was superior to previously reported values using the same aptamer in similar assay schemes with different detection platforms. These results point to the promising application of the Ara h 1 aptamer-functionalized particles in bioassay development. Copyright © 2016 Elsevier B.V. All rights reserved.
2011-01-01
Background There is a growing body of evidence that integrated packages of community-based interventions, a form of programming often implemented by NGOs, can have substantial child mortality impact. More countries may be able to meet Millennium Development Goal (MDG) 4 targets by leveraging such programming. Analysis of the mortality effect of this type of programming is hampered by the cost and complexity of direct mortality measurement. The Lives Saved Tool (LiST) produces an estimate of mortality reduction by modelling the mortality effect of changes in population coverage of individual child health interventions. However, few studies to date have compared the LiST estimates of mortality reduction with those produced by direct measurement. Methods Using results of a recent review of evidence for community-based child health programming, a search was conducted for NGO child health projects implementing community-based interventions that had independently verified child mortality reduction estimates, as well as population coverage data for modelling in LiST. One child survival project fit inclusion criteria. Subsequent searches of the USAID Development Experience Clearinghouse and Child Survival Grants databases and interviews of staff from NGOs identified no additional projects. Eight coverage indicators, covering all the project’s technical interventions were modelled in LiST, along with indicator values for most other non-project interventions in LiST, mainly from DHS data from 1997 and 2003. Results The project studied was implemented by World Relief from 1999 to 2003 in Gaza Province, Mozambique. An independent evaluation collecting pregnancy history data estimated that under-five mortality declined 37% and infant mortality 48%. Using project-collected coverage data, LiST produced estimates of 39% and 34% decline, respectively. Conclusions LiST gives reasonably accurate estimates of infant and child mortality decline in an area where a package of community-based interventions was implemented. This and other validation exercises support use of LiST as an aid for program planning to tailor packages of community-based interventions to the epidemiological context and for project evaluation. Such targeted planning and assessments will be useful to accelerate progress in reaching MDG4 targets. PMID:21501454
DOE Office of Scientific and Technical Information (OSTI.GOV)
Chiu, J; Ma, L
2015-06-15
Purpose: To develop a treatment delivery and planning strategy by increasing the number of beams to minimize dose to brain tissue surrounding a target, while maximizing dose coverage to the target. Methods: We analyzed 14 different treatment plans via Leksell PFX and 4C. For standardization, single tumor cases were chosen. Original treatment plans were compared with two optimized plans. The number of beams was increased in treatment plans by varying tilt angles of the patient head, while maintaining original isocenter and the beam positions in the x-, y- and z-axes, collimator size, and beam blocking. PFX optimized plans increased beammore » numbers with three pre-set tilt angles, 70, 90, 110, and 4C optimized plans increased beam numbers with tilt angles increasing arbitrarily from range of 30 to 150 degrees. Optimized treatment plans were compared dosimetrically with original treatment plans. Results: Comparing total normal tissue isodose volumes between original and optimized plans, the low-level percentage isodose volumes decreased in all plans. Despite the addition of multiple beams up to a factor of 25, beam-on times for 1 tilt angle versus 3 or more tilt angles were comparable (<1 min.). In 64% (9/14) of the studied cases, the volume percentage decrease by >5%, with the highest value reaching 19%. The addition of more tilt angles correlates to a greater decrease in normal brain irradiated volume. Selectivity and coverage for original and optimized plans remained comparable. Conclusion: Adding large number of additional focused beams with variable patient head tilt shows improvement for dose fall-off for brain radiosurgery. The study demonstrates technical feasibility of adding beams to decrease target volume.« less
Nefdt, Rory; Ribaira, Eric; Diallo, Khassoum
2014-10-01
To ensure correct and appropriate funding is available, there is a need to estimate resource needs for improved planning and implementation of integrated Community Case Management (iCCM). To compare and estimate costs for commodity and human resource needs for iCCM, based on treatment coverage rates, bottlenecks and national targets in Ethiopia, Kenya and Zambia from 2014 to 2016. Resource needs were estimated using Ministry of Health (MoH) targets fronm 2014 to 2016 for implementation of case management of pneumonia, diarrhea and malaria through iCCM based on epidemiological, demographic, economic, intervention coverage and other health system parameters. Bottleneck analysis adjusted cost estimates against system barriers. Ethiopia, Kenya and Zambia were chosen to compare differences in iCCM costs in different programmatic implementation landscapes. Coverage treatment rates through iCCM are lowest in Ethiopia, followed by Kenya and Zambia, but Ethiopia had the greatest increases between 2009 and 2012. Deployment of health extension workers (HEWs) in Ethiopia is more advanced compared to Kenya and Zambia, which have fewer equivalent cadres (called commu- nity health workers (CHWs)) covering a smaller proportion of the population. Between 2014 and 2016, the propor- tion of treatments through iCCM compared to health centres are set to increase from 30% to 81% in Ethiopia, 1% to 18% in Kenya and 3% to 22% in Zambia. The total estimated cost of iCCM for these three years are USD 75,531,376 for Ethiopia, USD 19,839,780 for Kenya and USD 33,667,742 for Zambia. Projected per capita expen- diture for 2016 is USD 0.28 for Ethiopia, USD 0.20 in Kenya and USD 0.98 in Zambia. Commodity costs for pneumonia and diarrhea were a small fraction of the total iCCM budget for all three countries (less than 3%), while around 80% of the costs related to human resources. Analysis of coverage, demography and epidemiology data improves estimates of fimding requirements for iCCM. Bottleneck analysis adjusts cost estimates by including system barriers, thus reflecting a more accurate estimate of potential resource utilization. Adding pneumonia and diarrhea interventions to existing large scale community-based malaria case management programs is likely to require relatively small and nationally affordable investments. iCCM can be implemented for USD 0.09 to 0.98 per capita per annum, depending on the stage of scale-up and targets set by the MoH.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Sakanaka, Katsuyuki; Mizowaki, Takashi, E-mail: mizo@kuhp.kyoto-u.ac.jp; Hiraoka, Masahiro
Purpose: To investigate the dosimetric advantage of intensity-modulated radiotherapy (IMRT) for whole ventricles (WV) in patients with a localized intracranial germinoma receiving induction chemotherapy. Methods and Materials: Data from 12 consecutive patients with localized intracranial germinomas who received induction chemotherapy and radiotherapy were used. Four-field coplanar three-dimensional conformal radiotherapy (3D-CRT) and seven-field coplanar IMRT plans were created. In both plans, 24 Gy was prescribed in 12 fractions for the planning target volume (PTV) involving WV and tumor bed. In IMRT planning, optimization was conducted to reduce the doses to the organs at risk (OARs) as much as possible, keeping themore » minimum dose equivalent to that of 3D-CRT. The 3D-CRT and IMRT plans were compared in terms of the dose-volume statistics for target coverage and the OARs. Results: IMRT significantly increased the percentage volume of the PTV receiving 24 Gy compared with 3D-CRT (93.5% vs. 84.8%; p = 0.007), while keeping target homogeneity equivalent to 3D-CRT (p = 0.869). The absolute percentage reduction in the irradiated volume of the normal brain receiving 100%, 75%, 50%, and 25% of 24 Gy ranged from 0.7% to 16.0% in IMRT compared with 3D-CRT (p < 0.001). No significant difference was observed in the volume of the normal brain receiving 10% and 5% of 24 Gy between IMRT and 3D-CRT. Conformation number was significantly improved in IMRT (p < 0.001). For other OARs, the mean dose to the cochlea was reduced significantly in IMRT by 22.3% of 24 Gy compared with 3D-CRT (p < 0.001). Conclusions: Compared with 3D-CRT, IMRT for WV improved the target coverage and reduced the irradiated volume of the normal brain in patients with intracranial germinomas receiving induction chemotherapy. IMRT for WV with induction chemotherapy could reduce the late side effects from cranial irradiation without compromising control of the tumor.« less
Multi-Objective Optimization of Spacecraft Trajectories for Small-Body Coverage Missions
NASA Technical Reports Server (NTRS)
Hinckley, David, Jr.; Englander, Jacob; Hitt, Darren
2017-01-01
Visual coverage of surface elements of a small-body object requires multiple images to be taken that meet many requirements on their viewing angles, illumination angles, times of day, and combinations thereof. Designing trajectories capable of maximizing total possible coverage may not be useful since the image target sequence and the feasibility of said sequence given the rotation-rate limitations of the spacecraft are not taken into account. This work presents a means of optimizing, in a multi-objective manner, surface target sequences that account for such limitations.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Krayenbuehl, Jerome Dipl.Phys. E.T.H.; Oertel, Susanne; Davis, J. Bernard
Purpose: The optimal technique for postoperative radiotherapy (RT) after extrapleural pleuropneumonectomy (EPP) of malignant pleural mesothelioma (MPM) remains debated. Methods and Materials: The data from 8 right-sided and 9 left-sided consecutive cases of MPM treated with RT after radical EPP were reviewed. Of the 17 patients, 8 had been treated with three-dimensional (3D) conformal RT (3D-CRT) and 9 with intensity-modulated RT (IMRT) with 6-MV photons. The clinical outcome and adverse events were assessed. For comparative planning, each case was replanned with 3D-CRT using photons and electrons or with IMRT. Homogeneity, doses to the organs at risk, and target volume coveragemore » were analyzed. Results: Both techniques yielded acceptable plans. The dose coverage and homogeneity of IMRT increased by 7.7% for the first planning target volume and 9.7% for the second planning target volume, ensuring {>=}95% of the prescribed dose compared with 3D-CRT (p < 0.01). Compared with 3D-CRT, IMRT increased the dose to the contralateral lung, with an increase in the mean lung dose of 7.8 Gy and an increase in the volume receiving 13 Gy and 20 Gy by 20.5% and 7.2%, respectively (p < 0.01). A negligible dose increase to the contralateral kidney and liver was observed. No differences were seen for the spinal cord and ipsilateral kidney. Two adverse events of clinical relevant lung toxicity were observed with IMRT. Conclusion: Intensity-modulated RT and 3D-CRT are both suitable for adjuvant RT. IMRT improves the planning target volume coverage but delivered greater doses to the organs at risk. Rigid dose constraints for the lung should be respected.« less
Kripke, Katharine; Hatzold, Karin; Mugurungi, Owen; Ncube, Gertrude; Xaba, Sinokuthemba; Gold, Elizabeth; Ahanda, Kim Seifert; Kruse-Levy, Natalie; Njeuhmeli, Emmanuel
2016-01-01
Zimbabwe aims to increase circumcision coverage to 80% among 13- to 29-year-olds. However, implementation data suggest that high coverage among men ages 20 and older may not be achievable without efforts specifically targeted to these men, incurring additional costs per circumcision. Scale-up scenarios were created based on trends in implementation data in Zimbabwe, and the cost-effectiveness of increasing efforts to recruit clients ages 20-29 was examined. Zimbabwe voluntary medical male circumcision (VMMC) program data were used to project trends in male circumcision coverage by age into the future. The projection informed a base scenario in which, by 2018, the country achieves 80% circumcision coverage among males ages 10-19 and lower levels of coverage among men above age 20. The Zimbabwe DMPPT 2.0 model was used to project costs and impacts, assuming a US$109 VMMC unit cost in the base scenario and a 3% discount rate. Two other scenarios assumed that the program could increase coverage among clients ages 20-29 with a corresponding increase in unit cost for these age groups. When circumcision coverage among men ages 20-29 is increased compared with a base scenario reflecting current implementation trends, fewer VMMCs are required to avert one infection. If more than 50% additional effort (reflected as multiplying the unit cost by >1.5) is required to double the increase in coverage among this age group compared with the base scenario, the cost per HIV infection averted is higher than in the base scenario. Although increased investment in recruiting VMMC clients ages 20-29 may lead to greater overall impact if recruitment efforts are successful, it may also lead to lower cost-effectiveness, depending on the cost of increasing recruitment. Programs should measure the relationship between increased effort and increased ability to attract this age group.
Selective robust optimization: A new intensity-modulated proton therapy optimization strategy
DOE Office of Scientific and Technical Information (OSTI.GOV)
Li, Yupeng; Niemela, Perttu; Siljamaki, Sami
2015-08-15
Purpose: To develop a new robust optimization strategy for intensity-modulated proton therapy as an important step in translating robust proton treatment planning from research to clinical applications. Methods: In selective robust optimization, a worst-case-based robust optimization algorithm is extended, and terms of the objective function are selectively computed from either the worst-case dose or the nominal dose. Two lung cancer cases and one head and neck cancer case were used to demonstrate the practical significance of the proposed robust planning strategy. The lung cancer cases had minimal tumor motion less than 5 mm, and, for the demonstration of the methodology,more » are assumed to be static. Results: Selective robust optimization achieved robust clinical target volume (CTV) coverage and at the same time increased nominal planning target volume coverage to 95.8%, compared to the 84.6% coverage achieved with CTV-based robust optimization in one of the lung cases. In the other lung case, the maximum dose in selective robust optimization was lowered from a dose of 131.3% in the CTV-based robust optimization to 113.6%. Selective robust optimization provided robust CTV coverage in the head and neck case, and at the same time improved controls over isodose distribution so that clinical requirements may be readily met. Conclusions: Selective robust optimization may provide the flexibility and capability necessary for meeting various clinical requirements in addition to achieving the required plan robustness in practical proton treatment planning settings.« less
Spiliopoulou, Athina; Colombo, Marco; Orchard, Peter; Agakov, Felix; McKeigue, Paul
2017-01-01
We address the task of genotype imputation to a dense reference panel given genotype likelihoods computed from ultralow coverage sequencing as inputs. In this setting, the data have a high-level of missingness or uncertainty, and are thus more amenable to a probabilistic representation. Most existing imputation algorithms are not well suited for this situation, as they rely on prephasing for computational efficiency, and, without definite genotype calls, the prephasing task becomes computationally expensive. We describe GeneImp, a program for genotype imputation that does not require prephasing and is computationally tractable for whole-genome imputation. GeneImp does not explicitly model recombination, instead it capitalizes on the existence of large reference panels—comprising thousands of reference haplotypes—and assumes that the reference haplotypes can adequately represent the target haplotypes over short regions unaltered. We validate GeneImp based on data from ultralow coverage sequencing (0.5×), and compare its performance to the most recent version of BEAGLE that can perform this task. We show that GeneImp achieves imputation quality very close to that of BEAGLE, using one to two orders of magnitude less time, without an increase in memory complexity. Therefore, GeneImp is the first practical choice for whole-genome imputation to a dense reference panel when prephasing cannot be applied, for instance, in datasets produced via ultralow coverage sequencing. A related future application for GeneImp is whole-genome imputation based on the off-target reads from deep whole-exome sequencing. PMID:28348060
Did the dependent coverage expansion increase risky substance use among young adults?
Breslau, Joshua; Yu, Hao; Han, Bing; Pacula, Rosalie L; Burns, Rachel M; Stein, Bradley D
2017-09-01
The dependent coverage expansion (DCE) enacted through the Affordable Care Act increased health insurance coverage among young adults. Increasing insurance coverage in this age group has the potential for unintended consequences on risky substance use. Repeated cross-sectional surveys were used to compare change in substance use during the period the DCE was implemented in the 19-25year old target age group (Pre-DCE n=15,772, Post-DCE n=22,719) with contemporaneous change in a slightly older age group that was not targeted by the policy (Pre-DCE=19,851, Post-DCE n=28,157). Outcomes include 11 measures of alcohol, illicit drug and cigarette use. Statistical controls were included for demographic and socioeconomic factors and for early initiation of substance use to adjust for historical trends in developmental trajectories. Risky substance use decreased in young adults relative to the older age group over the period that the DCE was implemented. However, statistical adjustment for initiation of substance use prior to age 18, which is prior to exposure to the DCE, accounted for the differences between the age groups. In adjusted models, associations between the DCE and substance use outcomes range from 0.96 to 1.08 with p-values ranging from 0.330 to 0.963. Historical trends in initiation of substance use prior to age 18, not the DCE, account for change in risky substance use among 19-25year olds relative to 26-34year olds. The evidence does not support the suggestion that health insurance coverage would increase risky substance use among young adults. Copyright © 2017 Elsevier B.V. All rights reserved.
MCMC-ODPR: primer design optimization using Markov Chain Monte Carlo sampling.
Kitchen, James L; Moore, Jonathan D; Palmer, Sarah A; Allaby, Robin G
2012-11-05
Next generation sequencing technologies often require numerous primer designs that require good target coverage that can be financially costly. We aimed to develop a system that would implement primer reuse to design degenerate primers that could be designed around SNPs, thus find the fewest necessary primers and the lowest cost whilst maintaining an acceptable coverage and provide a cost effective solution. We have implemented Metropolis-Hastings Markov Chain Monte Carlo for optimizing primer reuse. We call it the Markov Chain Monte Carlo Optimized Degenerate Primer Reuse (MCMC-ODPR) algorithm. After repeating the program 1020 times to assess the variance, an average of 17.14% fewer primers were found to be necessary using MCMC-ODPR for an equivalent coverage without implementing primer reuse. The algorithm was able to reuse primers up to five times. We compared MCMC-ODPR with single sequence primer design programs Primer3 and Primer-BLAST and achieved a lower primer cost per amplicon base covered of 0.21 and 0.19 and 0.18 primer nucleotides on three separate gene sequences, respectively. With multiple sequences, MCMC-ODPR achieved a lower cost per base covered of 0.19 than programs BatchPrimer3 and PAMPS, which achieved 0.25 and 0.64 primer nucleotides, respectively. MCMC-ODPR is a useful tool for designing primers at various melting temperatures at good target coverage. By combining degeneracy with optimal primer reuse the user may increase coverage of sequences amplified by the designed primers at significantly lower costs. Our analyses showed that overall MCMC-ODPR outperformed the other primer-design programs in our study in terms of cost per covered base.
MCMC-ODPR: Primer design optimization using Markov Chain Monte Carlo sampling
2012-01-01
Background Next generation sequencing technologies often require numerous primer designs that require good target coverage that can be financially costly. We aimed to develop a system that would implement primer reuse to design degenerate primers that could be designed around SNPs, thus find the fewest necessary primers and the lowest cost whilst maintaining an acceptable coverage and provide a cost effective solution. We have implemented Metropolis-Hastings Markov Chain Monte Carlo for optimizing primer reuse. We call it the Markov Chain Monte Carlo Optimized Degenerate Primer Reuse (MCMC-ODPR) algorithm. Results After repeating the program 1020 times to assess the variance, an average of 17.14% fewer primers were found to be necessary using MCMC-ODPR for an equivalent coverage without implementing primer reuse. The algorithm was able to reuse primers up to five times. We compared MCMC-ODPR with single sequence primer design programs Primer3 and Primer-BLAST and achieved a lower primer cost per amplicon base covered of 0.21 and 0.19 and 0.18 primer nucleotides on three separate gene sequences, respectively. With multiple sequences, MCMC-ODPR achieved a lower cost per base covered of 0.19 than programs BatchPrimer3 and PAMPS, which achieved 0.25 and 0.64 primer nucleotides, respectively. Conclusions MCMC-ODPR is a useful tool for designing primers at various melting temperatures at good target coverage. By combining degeneracy with optimal primer reuse the user may increase coverage of sequences amplified by the designed primers at significantly lower costs. Our analyses showed that overall MCMC-ODPR outperformed the other primer-design programs in our study in terms of cost per covered base. PMID:23126469
DOE Office of Scientific and Technical Information (OSTI.GOV)
Hernandez, Victor, E-mail: vhernandezmasgrau@gmail.com; Arenas, Meritxell; Müller, Katrin
2013-01-01
To assess the advantages of an optimized posterior axillary (AX) boost technique for the irradiation of supraclavicular (SC) and AX lymph nodes. Five techniques for the treatment of SC and levels I, II, and III AX lymph nodes were evaluated for 10 patients selected at random: a direct anterior field (AP); an anterior to posterior parallel pair (AP-PA); an anterior field with a posterior axillary boost (PAB); an anterior field with an anterior axillary boost (AAB); and an optimized PAB technique (OptPAB). The target coverage, hot spots, irradiated volume, and dose to organs at risk were evaluated and a statisticalmore » analysis comparison was performed. The AP technique delivered insufficient dose to the deeper AX nodes. The AP-PA technique produced larger irradiated volumes and higher mean lung doses than the other techniques. The PAB and AAB techniques originated excessive hot spots in most of the cases. The OptPAB technique produced moderate hot spots while maintaining a similar planning target volume (PTV) coverage, irradiated volume, and dose to organs at risk. This optimized technique combines the advantages of the PAB and AP-PA techniques, with moderate hot spots, sufficient target coverage, and adequate sparing of normal tissues. The presented technique is simple, fast, and easy to implement in routine clinical practice and is superior to the techniques historically used for the treatment of SC and AX lymph nodes.« less
Cho, Hyunyi; Hall, Jennifer G.; Kosmoski, Carin; Fox, Rebekah L.; Mastin, Teresa
2008-01-01
The majority of tanning bed users in the U.S. are women. Previous health communication research frequently focused on the risk of skin cancer, but few studies assessed the mediated communication environment that may surround women’s beliefs and behaviors relevant to tanning. A content analysis of articles in eight magazines targeting girls, young women, older women, and women who are interested in fitness during the ten-year period of 1997–2006 was conducted. The amount of coverage of tanning bed use consequences was less than 50% of the coverage of tanning benefits. About 40% of the tanning benefits coverage touted looking healthy. The coverage of prevention methods focused on sunscreen use (55%), while the more important methods (e.g., protective clothing use) were rarely featured. Longitudinally, the coverage of the risk and prevention relevant issues increased between 1997 and 2006. The data indicate that the coverage of tanning benefits also increased during the same period. PMID:20228954
DOE Office of Scientific and Technical Information (OSTI.GOV)
Zheng, Y; Chang, A; Liu, Y
Purpose: Electron beams are commonly used for boost radiation following whole breast irradiation (WBI) to improve the in-breast local control. Proton beams have a finite range and a sharper distal dose falloff compared to electron beams, thus potentially sparing more heart and lung in breast treatment. The purpose of the study is to compare protons with electrons for boost breast treatment in terms of target coverage and normal tissue sparing. Methods: Six breast cancer patients were included in this study. All women received WBI to 45–50 Gy, followed by a 10–16.2 Gy boost with standard fractionation. If proton beams weremore » used for the boost treatment, an electron plan was retrospectively generated for comparison using the same CT set and structures, and vice versa if electron beams were used for treatment. Proton plans were generated using the treatment planning system (TPS) with two to three uniform scanning proton beams. Electron plans were generated using the Pinnacle TPS with one single en face beam. Dose-volume histograms (DVH) were calculated and compared between proton and electron boost plans. Results: Proton plans show a similar boost target coverage, similar skin dose, and much better heart and lung sparing. For an example patient, V95% for PTV was 99.98% and skin (5 mm shell) received a max dose close to the prescription dose for both protons and electrons; however, V2 and V5 for the ipsilateral lung and heart were 37.5%, 17.9% and 19.9%, 4.9% respectively for electrons, but were essentially 0 for protons. Conclusions: This dosimetric comparison demonstrates that while both proton therapy and electron therapy provided similar coverage and skin dose, proton therapy could largely reduce the dose to lung and heart, thus leading to potential less side effects.« less
Worrall, Eve; Hill, Jenny; Webster, Jayne; Mortimer, Julia
2005-01-01
Widespread coverage of vulnerable populations with insecticide-treated nets (ITNs) constitutes an important component of the Roll Back Malaria (RBM) strategy to control malaria. The Abuja Targets call for 60% coverage of children under 5 years of age and pregnant women by 2005; but current coverage in Africa is unacceptably low. The RBM 'Strategic Framework for Coordinated National Action in Scaling-up Insecticide-Treated Netting Programmes in Africa' promotes coordinated national action and advocates sustained public provision of targeted subsidies to maximise public health benefits, alongside support and stimulation of the private sector. Several countries have already planned or initiated targeted subsidy schemes either on a pilot scale or on a national scale, and have valuable experience which can inform future interventions. The WHO RBM 'Workshop on mapping models for delivering ITNs through targeted subsidies' held in Zambia in 2003 provided an opportunity to share and document these country experiences. This paper brings together experiences presented at the workshop with other information on experiences of targeting subsidies on ITNs, net treatment kits and retreatment services (ITN products) in order to describe alternative approaches, highlight their similarities and differences, outline lessons learnt, and identify gaps in knowledge. We find that while there is a growing body of knowledge on different approaches to targeting ITN subsidies, there are significant gaps in knowledge in crucial areas. Key questions regarding how best to target, how much it will cost and what outcomes (levels of coverage) to expect remain unanswered. High quality, well-funded monitoring and evaluation of alternative approaches to targeting ITN subsidies is vital to develop a knowledge base so that countries can design and implement effective strategies to target ITN subsidies.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Feng, Z; Yu, G; Qin, S
Purpose: This study investigated that how the quality of adapted plan was affected by inter-fractional anatomy deformation by using one-step and two-step optimization for on line adaptive radiotherapy (ART) procedure. Methods: 10 lung carcinoma patients were chosen randomly to produce IMRT plan by one-step and two-step algorithms respectively, and the prescribed dose was set as 60 Gy on the planning target volume (PTV) for all patients. To simulate inter-fractional target deformation, four specific cases were created by systematic anatomy variation; including target superior shift 0.5 cm, 0.3cm contraction, 0.3 cm expansion and 45-degree rotation. Based on these four anatomy deformation,more » adapted plan, regenerated plan and non-adapted plan were created to evaluate quality of adaptation. Adapted plans were generated automatically by using one-step and two-step algorithms respectively to optimize original plans, and regenerated plans were manually created by experience physicists. Non-adapted plans were produced by recalculating the dose distribution based on corresponding original plans. The deviations among these three plans were statistically analyzed by paired T-test. Results: In PTV superior shift case, adapted plans had significantly better PTV coverage by using two-step algorithm compared with one-step one, and meanwhile there was a significant difference of V95 by comparison with adapted and non-adapted plans (p=0.0025). In target contraction deformation, with almost same PTV coverage, the total lung received lower dose using one-step algorithm than two-step algorithm (p=0.0143,0.0126 for V20, Dmean respectively). In other two deformation cases, there were no significant differences observed by both two optimized algorithms. Conclusion: In geometry deformation such as target contraction, with comparable PTV coverage, one-step algorithm gave better OAR sparing than two-step algorithm. Reversely, the adaptation by using two-step algorithm had higher efficiency and accuracy as target occurred position displacement. We want to thank Dr. Lei Xing and Dr. Yong Yang in the Stanford University School of Medicine for this work. This work was jointly supported by NSFC (61471226), Natural Science Foundation for Distinguished Young Scholars of Shandong Province (JQ201516), and China Postdoctoral Science Foundation (2015T80739, 2014M551949).« less
USDA-ARS?s Scientific Manuscript database
The ultimate goal of a pesticide spraying system is to provide adequate coverage on intended canopies with a minimum amount of spray materials and off-target waste. Better spray coverage requires an understanding of the fate and transport of spray droplets carried by turbulent airflows in orchards. ...
Decision making with regard to antiviral intervention during an influenza pandemic.
Shim, Eunha; Chapman, Gretchen B; Galvani, Alison P
2010-01-01
Antiviral coverage is defined by the proportion of the population that takes antiviral prophylaxis or treatment. High coverage of an antiviral drug has epidemiological and evolutionary repercussions. Antivirals select for drug resistance within the population, and individuals may experience adverse effects. To determine optimal antiviral coverage in the context of an influenza outbreak, we compared 2 perspectives: 1) the individual level (the Nash perspective), and 2) the population level (utilitarian perspective). We developed an epidemiological game-theoretic model of an influenza pandemic. The data sources were published literature and a national survey. The target population was the US population. The time horizon was 6 months. The perspective was individuals and the population overall. The interventions were antiviral prophylaxis and treatment. The outcome measures were the optimal coverage of antivirals in an influenza pandemic. At current antiviral pricing, the optimal Nash strategy is 0% coverage for prophylaxis and 30% coverage for treatment, whereas the optimal utilitarian strategy is 19% coverage for prophylaxis and 100% coverage for treatment. Subsidizing prophylaxis by $440 and treatment by $85 would bring the Nash and utilitarian strategies into alignment. For both prophylaxis and treatment, the optimal antiviral coverage decreases as pricing of antivirals increases. Our study does not incorporate the possibility of an effective vaccine and lacks probabilistic sensitivity analysis. Our survey also does not completely represent the US population. Because our model assumes a homogeneous population and homogeneous antiviral pricing, it does not incorporate heterogeneity of preference. The optimal antiviral coverage from the population perspective and individual perspectives differs widely for both prophylaxis and treatment strategies. Optimal population and individual strategies for prophylaxis and treatment might be aligned through subsidization.
Sensor-driven area coverage for an autonomous fixed-wing unmanned aerial vehicle.
Paull, Liam; Thibault, Carl; Nagaty, Amr; Seto, Mae; Li, Howard
2014-09-01
Area coverage with an onboard sensor is an important task for an unmanned aerial vehicle (UAV) with many applications. Autonomous fixed-wing UAVs are more appropriate for larger scale area surveying since they can cover ground more quickly. However, their non-holonomic dynamics and susceptibility to disturbances make sensor coverage a challenging task. Most previous approaches to area coverage planning are offline and assume that the UAV can follow the planned trajectory exactly. In this paper, this restriction is removed as the aircraft maintains a coverage map based on its actual pose trajectory and makes control decisions based on that map. The aircraft is able to plan paths in situ based on sensor data and an accurate model of the on-board camera used for coverage. An information theoretic approach is used that selects desired headings that maximize the expected information gain over the coverage map. In addition, the branch entropy concept previously developed for autonomous underwater vehicles is extended to UAVs and ensures that the vehicle is able to achieve its global coverage mission. The coverage map over the workspace uses the projective camera model and compares the expected area of the target on the ground and the actual area covered on the ground by each pixel in the image. The camera is mounted on a two-axis gimbal and can either be stabilized or optimized for maximal coverage. Hardware-in-the-loop simulation results and real hardware implementation on a fixed-wing UAV show the effectiveness of the approach. By including the already developed automatic takeoff and landing capabilities, we now have a fully automated and robust platform for performing aerial imagery surveys.
Decision Making with Regard to Antiviral Intervention during an Influenza Pandemic
Shim, Eunha; Chapman, Gretchen B.; Galvani, Alison P.
2012-01-01
Background Antiviral coverage is defined by the proportion of the population that takes antiviral prophylaxis or treatment. High coverage of an antiviral drug has epidemiological and evolutionary repercussions. Antivirals select for drug resistance within the population, and individuals may experience adverse effects. To determine optimal antiviral coverage in the context of an influenza outbreak, we compared 2 perspectives: 1) the individual level (the Nash perspective), and 2) the population level (utilitarian perspective). Methods We developed an epidemiological game-theoretic model of an influenza pandemic. The data sources were published literature and a national survey. The target population was the US population. The time horizon was 6 months. The perspective was individuals and the population overall. The interventions were antiviral prophylaxis and treatment. The outcome measures were the optimal coverage of antivirals in an influenza pandemic. Results At current antiviral pricing, the optimal Nash strategy is 0% coverage for prophylaxis and 30% coverage for treatment, whereas the optimal utilitarian strategy is 19% coverage for prophylaxis and 100% coverage for treatment. Subsidizing prophylaxis by $440 and treatment by $85 would bring the Nash and utilitarian strategies into alignment. For both prophylaxis and treatment, the optimal antiviral coverage decreases as pricing of antivirals increases. Our study does not incorporate the possibility of an effective vaccine and lacks probabilistic sensitivity analysis. Our survey also does not completely represent the US population. Because our model assumes a homogeneous population and homogeneous antiviral pricing, it does not incorporate heterogeneity of preference. Conclusions The optimal antiviral coverage from the population perspective and individual perspectives differs widely for both prophylaxis and treatment strategies. Optimal population and individual strategies for prophylaxis and treatment might be aligned through subsidization. PMID:20634545
DOE Office of Scientific and Technical Information (OSTI.GOV)
Pasciuti, Katia, E-mail: k.pasciuti@virgilio.it; Kuthpady, Shrinivas; Anderson, Anne
To examine tumor's and organ's response when different radiotherapy plan techniques are used. Ten patients with confirmed bladder tumors were first treated using 3-dimensional conformal radiotherapy (3DCRT) and subsequently the original plans were re-optimized using the intensity-modulated radiation treatment (IMRT) and volumetric-modulated arc therapy (VMAT)-techniques. Targets coverage in terms of conformity and homogeneity index, TCP, and organs' dose limits, including integral dose analysis were evaluated. In addition, MUs and treatment delivery times were compared. Better minimum target coverage (1.3%) was observed in VMAT plans when compared to 3DCRT and IMRT ones confirmed by a statistically significant conformity index (CI) results.more » Large differences were observed among techniques in integral dose results of the femoral heads. Even if no statistically significant differences were reported in rectum and tissue, a large amount of energy deposition was observed in 3DCRT plans. In any case, VMAT plans provided better organs and tissue sparing confirmed also by the normal tissue complication probability (NTCP) analysis as well as a better tumor control probability (TCP) result. Our analysis showed better overall results in planning using VMAT techniques. Furthermore, a total time reduction in treatment observed among techniques including gantry and collimator rotation could encourage using the more recent one, reducing target movements and patient discomfort.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Rosenthal, David I., E-mail: dirosenthal@mdanderson.or; Fuller, Clifton D.; Barker, Jerry L.
2010-06-01
Purpose: To investigate the dosimetry and feasibility of carotid-sparing intensity-modulated radiotherapy (IMRT) for early glottic cancer and to report preliminary clinical experience. Methods and Materials: Digital Imaging and Communications in Medicine radiotherapy (DICOM-RT) datasets from 6 T1-2 conventionally treated glottic cancer patients were used to create both conventional IMRT plans. We developed a simplified IMRT planning algorithm with three fields and limited segments. Conventional and IMRT plans were compared using generalized equivalent uniform dose and dose-volume parameters for in-field carotid arteries, target volumes, and organs at risk. We have treated 11 patients with this simplified IMRT technique. Results: Intensity-modulated radiotherapymore » consistently reduced radiation dose to the carotid arteries (p < 0.05) while maintaining the clinical target volume coverage. With conventional planning, median carotid V35, V50, and V63 were 100%, 100%, and 69.0%, respectively. With IMRT planning these decreased to 2%, 0%, and 0%, respectively (p < 0.01). Radiation planning and treatment times were similar for conventional radiotherapy and IMRT. Treatment results have been excellent thus far. Conclusions: Intensity-modulated radiotherapy significantly reduced unnecessary radiation dose to the carotid arteries compared with conventional lateral fields while maintaining clinical target volume coverage. Further experience and longer follow-up will be required to demonstrate outcomes for cancer control and carotid artery effects.« less
Leyvraz, Magali; Rohner, Fabian; Konan, Amoin G; Esso, Lasme J C E; Woodruff, Bradley A; Norte, Augusto; Adiko, Adiko F; Bonfoh, Bassirou; Aaron, Grant J
2016-01-01
Poor complementary feeding practices among infants and young children in Côte d'Ivoire are major contributing factors to the country's high burden of malnutrition. As part of a broad effort to address this issue, an affordable, nutritious, and locally produced fortified complementary food product was launched in the Côte d'Ivoire in 2011. The objective of the current research was to assess various levels of coverage of the program and to identify coverage barriers. A cross-sectional household survey was conducted among caregivers of children less than 2-years of age living in Abidjan, Côte d'Ivoire. Four measures of coverage were assessed: "message coverage" (i.e., has the caregiver ever heard of the product?), "contact coverage" (i.e., has the caregiver ever fed the child the product?), "partial coverage" (i.e., has the caregiver fed the child the product in the previous month?), and "effective coverage" (i.e., has the caregiver fed the child the product in the previous 7 days?). A total of 1,113 caregivers with children between 0 and 23 months of age were interviewed. Results showed high message coverage (85.0%), moderate contact coverage (37.8%), and poor partial and effective coverages (8.8% and 4.6%, respectively). Product awareness was lower among caregivers from poorer households, but partial and effective coverages were comparable in both poor and non-poor groups. Infant and young child feeding (IYCF) practices were generally poor and did not appear to have improved since previous assessments. In conclusion, the results from the present study indicate that availability on the market and high awareness among the target population is not sufficient to achieve high and effective coverage. With market-based delivery models, significant efforts are needed to improve demand. Moreover, given the high prevalence of malnutrition and poor IYCF practices, additional modes of delivering IYCF interventions and improving IYCF practices should be considered.
Chen, Shun-Li; Wu, Shiaw-Lin; Huang, Li-Juan; Huang, Jia-Bao; Chen, Shu-Hui
2013-06-01
Liquid chromatography-tandem mass spectrometry-based proteomics for peptide mapping and sequencing was used to characterize the marketed monoclonal antibody trastuzumab and compare it with two biosimilar products, mAb A containing D359E and L361M variations at the Fc site and mAb B without variants. Complete sequence coverage (100%) including disulfide linkages, glycosylations and other commonly occurring modifications (i.e., deamidation, oxidation, dehydration and K-clipping) were identified using maps generated from multi-enzyme digestions. In addition to the targeted comparison for the relative populations of targeted modification forms, a non-targeted approach was used to globally compare ion intensities in tryptic maps. The non-targeted comparison provided an extra-dimensional view to examine any possible differences related to variants or modifications. A peptide containing the two variants in mAb A, D359E and L361M, was revealed using the non-targeted comparison of the tryptic maps. In contrast, no significant differences were observed when trastuzumab was self-compared or compared with mAb B. These results were consistent with the data derived from peptide sequencing via collision induced dissociation/electron transfer dissociation. Thus, combined targeted and non-targeted approaches using powerful mass spectrometry-based proteomic tools hold great promise for the structural characterization of biosimilar products. Copyright © 2013 Elsevier B.V. All rights reserved.
Leyvraz, Magali; Wirth, James P; Woodruff, Bradley A; Sankar, Rajan; Sodani, Prahlad R; Sharma, Narottam D; Aaron, Grant J
2016-01-01
The Integrated Child Development Services (ICDS) in the State of Telangana, India, freely provides a fortified complementary food product, Bal Amrutham, as a take-home ration to children 6-35 months of age. In order to understand the potential for impact of any intervention, it is essential to assess coverage and utilization of the program and to address the barriers to its coverage and utilization. A two-stage, stratified cross-sectional cluster survey was conducted to estimate the coverage and utilization of Bal Amrutham and to identify their barriers and drivers. In randomly selected catchment areas of ICDS centers, children under 36 months of age were randomly selected. A questionnaire, constructed from different validated and standard modules and designed to collect coverage data on nutrition programs, was administered to caregivers. A total of 1,077 children were enrolled in the survey. The coverage of the fortified take-home ration was found to be high among the target population. Nearly all caregivers (93.7%) had heard of Bal Amrutham and 86.8% had already received the product for the target child. Among the children surveyed, 57.2% consumed the product regularly. The ICDS program's services were not found to be a barrier to product coverage. In fact, the ICDS program was found to be widely available, accessible, accepted, and utilized by the population in both urban and rural catchment areas, as well as among poor and non-poor households. However, two barriers to optimal coverage were found: the irregular supply of the product to the beneficiaries and the intra-household sharing of the product. Although sharing was common, the product was estimated to provide the target children with significant proportions of the daily requirements of macro- and micronutrients. Bal Amrutham is widely available, accepted, and consumed among the target population in the catchment areas of ICDS centers. The coverage of the product could be further increased by improving the supply chain.
Arbyn, Marc; Simoens, Cindy; Van Oyen, Herman; Foidart, Jean-Michel; Goffin, Frédéric; Simon, Philippe; Fabri, Valérie
2009-05-01
Cervical cancer screening by surveys overestimate coverage because of selection and reporting biases. The prepared Inter-Mutualistic Agency dataset has about 13 million records from Pap smears, colposcopies, cervical biopsies and surgery, performed in Belgium between 1996 and 2000. Cervical cancer screening coverage was defined as the proportion of the target population (women of 25-64 years) that has had a Pap smear taken within the last 3 years. Proportions and incidence rates were computed using official population data of the corresponding age group, area and calendar year. Cervical cancer screening coverage, in the period 1998-2000, was 59% at national level, for the target age group 25-64 years. Differences were small between the 3 regions. Variation ranged from 39% to 71%. Coverage was 64% for 25-29 year old women, 67% for those aged 30-39 years, 56% for those aged 50-54. The modal screening interval was 1 year. In the 3-year period 1998-2000, 3 million smears were taken from the 2.7 million women in the age group 25-64. Only 1.6 million women of the target group got one or more smears in that period and 1.1 million women had no smears, corresponding to an average of 1.88 smears per woman. Coverage reached only 59%, but the number of smears used was sufficient to cover more than 100% of the target population. Structural reduction of overuse and extension of coverage is warranted.
Global investment targets for malaria control and elimination between 2016 and 2030
Patouillard, Edith; Griffin, Jamie; Bhatt, Samir; Ghani, Azra; Cibulskis, Richard
2017-01-01
Background Access to malaria control interventions falls short of universal health coverage. The Global Technical Strategy for malaria targets at least 90% reduction in case incidence and mortality rates, and elimination in 35 countries by 2030. The potential to reach these targets will be determined in part by investments in malaria. This study estimates the financing required for malaria control and elimination over the 2016–2030 period. Methods A mathematical transmission model was used to explore the impact of increasing intervention coverage on burden and costs. The cost analysis took a public provider perspective covering all 97 malaria endemic countries and territories in 2015. All control interventions currently recommended by the WHO were considered. Cost data were sourced from procurement databases, the peer-reviewed literature, national malaria strategic plans, the WHO-CHOICE project and key informant interviews. Results Annual investments of $6.4 billion (95% uncertainty interval (UI $4.5–$9.0 billion)) by 2020, $7.7 billion (95% UI $5.4–$10.9 billion) by 2025 and $8.7 billion (95% UI $6.0–$12.3 billion) by 2030 will be required to reach the targets set in the Global Technical Strategy. These are equivalent to annual investment per person at risk of malaria of US$3.90 by 2020, US$4.30 by 2025 and US$4.40 by 2030, compared with US$2.30 if interventions were sustained at current coverage levels. The 20 countries with the highest burden in 2015 will require 88% of the total investment. Conclusions Given the challenges in increasing domestic and international funding, the efficient use of currently available resources should be a priority. PMID:29242750
Global investment targets for malaria control and elimination between 2016 and 2030.
Patouillard, Edith; Griffin, Jamie; Bhatt, Samir; Ghani, Azra; Cibulskis, Richard
2017-01-01
Access to malaria control interventions falls short of universal health coverage. The Global Technical Strategy for malaria targets at least 90% reduction in case incidence and mortality rates, and elimination in 35 countries by 2030. The potential to reach these targets will be determined in part by investments in malaria. This study estimates the financing required for malaria control and elimination over the 2016-2030 period. A mathematical transmission model was used to explore the impact of increasing intervention coverage on burden and costs. The cost analysis took a public provider perspective covering all 97 malaria endemic countries and territories in 2015. All control interventions currently recommended by the WHO were considered. Cost data were sourced from procurement databases, the peer-reviewed literature, national malaria strategic plans, the WHO-CHOICE project and key informant interviews. Annual investments of $6.4 billion (95% uncertainty interval (UI $4.5-$9.0 billion)) by 2020, $7.7 billion (95% UI $5.4-$10.9 billion) by 2025 and $8.7 billion (95% UI $6.0-$12.3 billion) by 2030 will be required to reach the targets set in the Global Technical Strategy. These are equivalent to annual investment per person at risk of malaria of US$3.90 by 2020, US$4.30 by 2025 and US$4.40 by 2030, compared with US$2.30 if interventions were sustained at current coverage levels. The 20 countries with the highest burden in 2015 will require 88% of the total investment. Given the challenges in increasing domestic and international funding, the efficient use of currently available resources should be a priority.
Oral Cholera Vaccine Coverage during an Outbreak and Humanitarian Crisis, Iraq, 2015.
Lam, Eugene; Al-Tamimi, Wasan; Russell, Steven Paul; Butt, Muhammad Obaid-Ul Islam; Blanton, Curtis; Musani, Altaf Sadrudin; Date, Kashmira
2017-01-01
During November-December 2015, as part of the 2015 cholera outbreak response in Iraq, the Iraqi Ministry of Health targeted ≈255,000 displaced persons >1 year of age with 2 doses of oral cholera vaccine (OCV). All persons who received vaccines were living in selected refugee camps, internally displaced persons camps, and collective centers. We conducted a multistage cluster survey to obtain OCV coverage estimates in 10 governorates that were targeted during the campaign. In total, 1,226 household and 5,007 individual interviews were conducted. Overall, 2-dose OCV coverage in the targeted camps was 87% (95% CI 85%-89%). Two-dose OCV coverage in the 3 northern governorates (91%; 95% CI 87%-94%) was higher than that in the 7 southern and central governorates (80%; 95% CI 77%-82%). The experience in Iraq demonstrates that OCV campaigns can be successfully implemented as part of a comprehensive response to cholera outbreaks among high-risk populations in conflict settings.
2016-01-01
This study quantified the interplay and gradient effects on GTV dose coverage for 3D CRT, dMLC IMRT, and VMAT SABR treatments for target amplitudes of 5–30 mm using 3DVH v3.1 software incorporating 4D Respiratory MotionSim (4D RMS) module. For clinically relevant motion periods (5 s), the interplay effect was small, with deviations in the minimum dose covering the target volume (D99%) of less than ±2.5% for target amplitudes up to 30 mm. Increasing the period to 60 s resulted in interplay effects of up to ±15.0% on target D99% dose coverage. The gradient effect introduced by target motion resulted in deviations of up to ±3.5% in D99% target dose coverage. VMAT treatments showed the largest deviation in dose metrics, which was attributed to the long delivery times in comparison to dMLC IMRT. Retrospective patient analysis indicated minimal interplay and gradient effects for patients treated with dMLC IMRT at the NCCI. PACS numbers: 87.55.km, 87.56.Fc PMID:26894347
Yang, Zhe; Luo, Xingen; Zhang, Xiaofang; Liu, Jie; Jiang, Qing
2013-04-01
Lipid-polymer hybrid nanoparticles (NPs) combining the positive attributes of both liposomes and polymeric NPs are increasingly being considered as promising candidates to carry therapeutic agents safely and efficiently into targeted sites. Herein, a modified emulsification technique was developed and optimized for the targeting lipid-polymer hybrid NPs fabrication; the surface properties and stability of the hybrid NPs were systematically investigated, which confirmed that the hybrid NPs consisted of a poly (lactide-co-glycolide) core with ∼90% surface coverage of the lipid monolayer and a ∼4.4 nm hydrated polyethylene glycol (PEG) shell. Optimization results showed that the lipid:polymer mass ratio and the lipid-PEG:lipid molar ratio could affect the size, lipid association efficiency and stability of hybrid NPs. Furthermore, a model chemotherapy drug, 10-hydroxycamptothecin, was encapsulated into hybrid NPs with a higher drug loading compared to PLGA NPs. Surface modification of the lipid layer and the PEG conjugated targeting ligand did not affect their drug release kinetics. Finally, the cytotoxicity and cellular uptake studies indicated that the lipid coverage and the c(RGDyk) conjugation of the hybrid NPs gained a significantly enhanced ability of cell killing and endocytosis. Our results suggested that lipid-polymer hybrid NPs prepared by the modified emulsion technique have great potential to be utilized as an engineered drug delivery system with precise control ability of surface targeting modification.
Inverse 4D conformal planning for lung SBRT using particle swarm optimization
NASA Astrophysics Data System (ADS)
Modiri, A.; Gu, X.; Hagan, A.; Bland, R.; Iyengar, P.; Timmerman, R.; Sawant, A.
2016-08-01
A critical aspect of highly potent regimens such as lung stereotactic body radiation therapy (SBRT) is to avoid collateral toxicity while achieving planning target volume (PTV) coverage. In this work, we describe four dimensional conformal radiotherapy using a highly parallelizable swarm intelligence-based stochastic optimization technique. Conventional lung CRT-SBRT uses a 4DCT to create an internal target volume and then, using forward-planning, generates a 3D conformal plan. In contrast, we investigate an inverse-planning strategy that uses 4DCT data to create a 4D conformal plan, which is optimized across the three spatial dimensions (3D) as well as time, as represented by the respiratory phase. The key idea is to use respiratory motion as an additional degree of freedom. We iteratively adjust fluence weights for all beam apertures across all respiratory phases considering OAR sparing, PTV coverage and delivery efficiency. To demonstrate proof-of-concept, five non-small-cell lung cancer SBRT patients were retrospectively studied. The 4D optimized plans achieved PTV coverage comparable to the corresponding clinically delivered plans while showing significantly superior OAR sparing ranging from 26% to 83% for D max heart, 10%-41% for D max esophagus, 31%-68% for D max spinal cord and 7%-32% for V 13 lung.
Inverse 4D conformal planning for lung SBRT using particle swarm optimization
Modiri, A; Gu, X; Hagan, A; Bland, R; Iyengar, P; Timmerman, R; Sawant, A
2016-01-01
A critical aspect of highly potent regimens such as lung stereotactic body radiation therapy (SBRT) is to avoid collateral toxicity while achieving planning target volume (PTV) coverage. In this work, we describe four dimensional conformal radiotherapy (4D CRT) using a highly parallelizable swarm intelligence-based stochastic optimization technique. Conventional lung CRT-SBRT uses a 4DCT to create an internal target volume (ITV) and then, using forward-planning, generates a 3D conformal plan. In contrast, we investigate an inverse-planning strategy that uses 4DCT data to create a 4D conformal plan, which is optimized across the three spatial dimensions (3D) as well as time, as represented by the respiratory phase. The key idea is to use respiratory motion as an additional degree of freedom. We iteratively adjust fluence weights for all beam apertures across all respiratory phases considering OAR sparing, PTV coverage and delivery efficiency. To demonstrate proof-of-concept, five non-small-cell lung cancer SBRT patients were retrospectively studied. The 4D optimized plans achieved PTV coverage comparable to the corresponding clinically delivered plans while showing significantly superior OAR sparing ranging from 26% to 83% for Dmax heart, 10% to 41% for Dmax esophagus, 31% to 68% for Dmax spinal cord and 7% to 32% for V13 lung. PMID:27476472
State of equity: childhood immunization in the World Health Organization African Region
Casey, Rebecca Mary; Hampton, Lee McCalla; Anya, Blanche-philomene Melanga; Gacic-Dobo, Marta; Diallo, Mamadou Saliou; Wallace, Aaron Stuart
2017-01-01
Introduction In 2010, the Global Vaccine Action Plan called on all countries to reach and sustain 90% national coverage and 80% coverage in all districts for the third dose of diphtheria-tetanus-pertussis vaccine (DTP3) by 2015 and for all vaccines in national immunization schedules by 2020. The aims of this study are to analyze recent trends in national vaccination coverage in the World Health Organization African Region andto assess how these trends differ by country income category. Methods We compared national vaccination coverage estimates for DTP3 and the first dose of measles-containing vaccine (MCV) obtained from the World Health Organization (WHO)/United Nations Children’s Fund (UNICEF) joint estimates of national immunization coverage for all African Region countries. Using United Nations (UN) population estimates of surviving infants and country income category for the corresponding year, we calculated population-weighted average vaccination coverage by country income category (i.e., low, lower middle, and upper middle-income) for the years 2000, 2005, 2010 and 2015. Results DTP3 coverage in the African Region increased from 52% in 2000 to 76% in 2015,and MCV1 coverage increased from 53% to 74% during the same period, but with considerable differences among countries. Thirty-six African Region countries were low income in 2000 with an average DTP3 coverage of 50% while 26 were low income in 2015 with an average coverage of 80%. Five countries were lower middle-income in 2000 with an average DTP3 coverage of 84% while 12 were lower middle-income in 2015 with an average coverage of 69%. Five countries were upper middle-income in 2000 with an average DTP3 coverage of 73% and eight were upper middle-income in 2015 with an average coverage of 76%. Conclusion Disparities in vaccination coverage by country persist in the African Region, with countries that were lower middle-income having the lowest coverage on average in 2015. Monitoring and addressing these disparities is essential for meeting global immunization targets. PMID:29296140
Formal methods for test case generation
NASA Technical Reports Server (NTRS)
Rushby, John (Inventor); De Moura, Leonardo Mendonga (Inventor); Hamon, Gregoire (Inventor)
2011-01-01
The invention relates to the use of model checkers to generate efficient test sets for hardware and software systems. The method provides for extending existing tests to reach new coverage targets; searching *to* some or all of the uncovered targets in parallel; searching in parallel *from* some or all of the states reached in previous tests; and slicing the model relative to the current set of coverage targets. The invention provides efficient test case generation and test set formation. Deep regions of the state space can be reached within allotted time and memory. The approach has been applied to use of the model checkers of SRI's SAL system and to model-based designs developed in Stateflow. Stateflow models achieving complete state and transition coverage in a single test case are reported.
Evaluation of target coverage and margins adequacy during CyberKnife Lung Optimized Treatment.
Ricotti, Rosalinda; Seregni, Matteo; Ciardo, Delia; Vigorito, Sabrina; Rondi, Elena; Piperno, Gaia; Ferrari, Annamaria; Zerella, Maria Alessia; Arculeo, Simona; Francia, Claudia Maria; Sibio, Daniela; Cattani, Federica; De Marinis, Filippo; Spaggiari, Lorenzo; Orecchia, Roberto; Riboldi, Marco; Baroni, Guido; Jereczek-Fossa, Barbara Alicja
2018-04-01
Evaluation of target coverage and verification of safety margins, in motion management strategies implemented by Lung Optimized Treatment (LOT) module in CyberKnife system. Three fiducial-less motion management strategies provided by LOT can be selected according to tumor visibility in the X ray images acquired during treatment. In 2-view modality the tumor is visible in both X ray images and full motion tracking is performed. In 1-view modality the tumor is visible in a single X ray image, therefore, motion tracking is combined with an internal target volume (ITV)-based margin expansion. In 0-view modality the lesion is not visible, consequently the treatment relies entirely on an ITV-based approach. Data from 30 patients treated in 2-view modality were selected providing information on the three-dimensional tumor motion in correspondence to each X ray image. Treatments in 1-view and 0-view modalities were simulated by processing log files and planning volumes. Planning target volume (PTV) margins were defined according to the tracking modality: end-exhale clinical target volume (CTV) + 3 mm in 2-view and ITV + 5 mm in 0-view. In the 1-view scenario, the ITV encompasses only tumor motion along the non-visible direction. Then, non-uniform ITV to PTV margins were applied: 3 mm and 5 mm in the visible and non-visible direction, respectively. We defined the coverage of each voxel of the CTV as the percentage of X ray images where such voxel was included in the PTV. In 2-view modality coverage was calculated as the intersection between the CTV centred on the imaged target position and the PTV centred on the predicted target position, as recorded in log files. In 1-view modality, coverage was calculated as the intersection between the CTV centred on the imaged target position and the PTV centred on the projected predictor data. In 0-view modality coverage was calculated as the intersection between the CTV centred on the imaged target position and the non-moving PTV. Similar to dose-volume histogram, CTV coverage-volume histograms (defined as CVH) were derived for each patient and treatment modality. The geometric coverages of the 90% and 95% of CTV volume (C90, C95, respectively) were evaluated. Patient-specific optimal margins (ensuring C95 ≥ 95%) were computed retrospectively. The median ± interquartile-rage of C90 and C95 for upper lobe lesions was 99.1 ± 0.6% and 99.0 ± 3.1%, whereas they were 98.9 ± 4.2% and 97.8 ± 7.5% for lower and middle lobe tumors. In 2-view, 1-view and 0-view modality, adopted margins ensured C95 ≥ 95% in 70%, 85% and 63% of cases and C95 ≥ 90% in 90%, 88% and 83% of cases, respectively. In 2-view, 1-view and 0-view a reduction in margins still ensured C95 ≥ 95% in 33%, 78% and 59% of cases, respectively. CTV coverage analysis provided an a-posteriori evaluation of the treatment geometric accuracy and allowed a quantitative verification of the adequacy of the PTV margins applied in CyberKnife LOT treatments offering guidance in the selection of CTV margins. © 2018 American Association of Physicists in Medicine.
Barry, Aisling; Rock, Kathy; Sole, Claudio; Rahman, Mohammad; Pintilie, Melania; Lee, Grace; Fyles, Anthony; Koch, C Anne
The purpose of this study was to evaluate the impact of the active breathing control (ABC) technique on IMN coverage and organs at risk in patients planned for postmastectomy radiation therapy (PMRT), with the inclusion of the internal mammary lymph nodes (IMNs). The effect of body mass index (BMI) on recorded dosimetric parameters was examined in the same patient cohort. Fifty left-sided postmastectomy patients with breast cancer who underwent free-breathing (FB) and ABC-Elekta CT simulation scans were selected at random from an institutional breast cancer database between 2008 and 2014. The ABC plans were directly compared with FB plans from the same patient. The IMN planning target volume coverage met dosimetric criteria for coverage of receiving more than 90% of the prescribed dose (V90) >90%, although it decreased with ABC compared with FB (94.5% vs 98%, P < .001). Overall, ABC significantly reduced doses to all measured heart and left anterior descending coronary artery parameters, ipsilateral lung V20, and mean lung dose compared with FB (P < .001). There was no difference seen between the ABC and FB plans with respect to the dose to contralateral lung or contralateral breast. There was no correlation identified between BMI and any of the dosimetric parameters recorded from the ABC and FB plans. Our results suggest that ABC reduces IMN coverage in left-sided breast cancer patients planned for PMRT; however, dosimetric criteria for IMN coverage were still met, suggesting that this is not likely to be clinically significant. ABC led to significant sparing of organs at risk compared with FB conditions and was not affected by BMI. Collectively, the results support the use of ABC for breast cancer patients undergoing left-sided PMRT requiring regional nodal irradiation that includes the IMNs. Further prospective clinical studies are required to determine the impact of these results on late normal tissue effects. Crown Copyright © 2016. Published by Elsevier Inc. All rights reserved.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Warren, Samantha, E-mail: samantha.warren@oncology.ox.ac.uk; Partridge, Mike; Bolsi, Alessandra
Purpose: Planning studies to compare x-ray and proton techniques and to select the most suitable technique for each patient have been hampered by the nonequivalence of several aspects of treatment planning and delivery. A fair comparison should compare similarly advanced delivery techniques from current clinical practice and also assess the robustness of each technique. The present study therefore compared volumetric modulated arc therapy (VMAT) and single-field optimization (SFO) spot scanning proton therapy plans created using a simultaneous integrated boost (SIB) for dose escalation in midesophageal cancer and analyzed the effect of setup and range uncertainties on these plans. Methods andmore » Materials: For 21 patients, SIB plans with a physical dose prescription of 2 Gy or 2.5 Gy/fraction in 25 fractions to planning target volume (PTV){sub 50Gy} or PTV{sub 62.5Gy} (primary tumor with 0.5 cm margins) were created and evaluated for robustness to random setup errors and proton range errors. Dose–volume metrics were compared for the optimal and uncertainty plans, with P<.05 (Wilcoxon) considered significant. Results: SFO reduced the mean lung dose by 51.4% (range 35.1%-76.1%) and the mean heart dose by 40.9% (range 15.0%-57.4%) compared with VMAT. Proton plan robustness to a 3.5% range error was acceptable. For all patients, the clinical target volume D{sub 98} was 95.0% to 100.4% of the prescribed dose and gross tumor volume (GTV) D{sub 98} was 98.8% to 101%. Setup error robustness was patient anatomy dependent, and the potential minimum dose per fraction was always lower with SFO than with VMAT. The clinical target volume D{sub 98} was lower by 0.6% to 7.8% of the prescribed dose, and the GTV D{sub 98} was lower by 0.3% to 2.2% of the prescribed GTV dose. Conclusions: The SFO plans achieved significant sparing of normal tissue compared with the VMAT plans for midesophageal cancer. The target dose coverage in the SIB proton plans was less robust to random setup errors and might be unacceptable for certain patients. Robust optimization to ensure adequate target coverage of SIB proton plans might be beneficial.« less
Warren, Samantha; Partridge, Mike; Bolsi, Alessandra; Lomax, Anthony J.; Hurt, Chris; Crosby, Thomas; Hawkins, Maria A.
2016-01-01
Purpose Planning studies to compare x-ray and proton techniques and to select the most suitable technique for each patient have been hampered by the nonequivalence of several aspects of treatment planning and delivery. A fair comparison should compare similarly advanced delivery techniques from current clinical practice and also assess the robustness of each technique. The present study therefore compared volumetric modulated arc therapy (VMAT) and single-field optimization (SFO) spot scanning proton therapy plans created using a simultaneous integrated boost (SIB) for dose escalation in midesophageal cancer and analyzed the effect of setup and range uncertainties on these plans. Methods and Materials For 21 patients, SIB plans with a physical dose prescription of 2 Gy or 2.5 Gy/fraction in 25 fractions to planning target volume (PTV)50Gy or PTV62.5Gy (primary tumor with 0.5 cm margins) were created and evaluated for robustness to random setup errors and proton range errors. Dose–volume metrics were compared for the optimal and uncertainty plans, with P<.05 (Wilcoxon) considered significant. Results SFO reduced the mean lung dose by 51.4% (range 35.1%-76.1%) and the mean heart dose by 40.9% (range 15.0%-57.4%) compared with VMAT. Proton plan robustness to a 3.5% range error was acceptable. For all patients, the clinical target volume D98 was 95.0% to 100.4% of the prescribed dose and gross tumor volume (GTV) D98 was 98.8% to 101%. Setup error robustness was patient anatomy dependent, and the potential minimum dose per fraction was always lower with SFO than with VMAT. The clinical target volume D98 was lower by 0.6% to 7.8% of the prescribed dose, and the GTV D98 was lower by 0.3% to 2.2% of the prescribed GTV dose. Conclusions The SFO plans achieved significant sparing of normal tissue compared with the VMAT plans for midesophageal cancer. The target dose coverage in the SIB proton plans was less robust to random setup errors and might be unacceptable for certain patients. Robust optimization to ensure adequate target coverage of SIB proton plans might be beneficial. PMID:27084641
Warren, Samantha; Partridge, Mike; Bolsi, Alessandra; Lomax, Anthony J; Hurt, Chris; Crosby, Thomas; Hawkins, Maria A
2016-05-01
Planning studies to compare x-ray and proton techniques and to select the most suitable technique for each patient have been hampered by the nonequivalence of several aspects of treatment planning and delivery. A fair comparison should compare similarly advanced delivery techniques from current clinical practice and also assess the robustness of each technique. The present study therefore compared volumetric modulated arc therapy (VMAT) and single-field optimization (SFO) spot scanning proton therapy plans created using a simultaneous integrated boost (SIB) for dose escalation in midesophageal cancer and analyzed the effect of setup and range uncertainties on these plans. For 21 patients, SIB plans with a physical dose prescription of 2 Gy or 2.5 Gy/fraction in 25 fractions to planning target volume (PTV)50Gy or PTV62.5Gy (primary tumor with 0.5 cm margins) were created and evaluated for robustness to random setup errors and proton range errors. Dose-volume metrics were compared for the optimal and uncertainty plans, with P<.05 (Wilcoxon) considered significant. SFO reduced the mean lung dose by 51.4% (range 35.1%-76.1%) and the mean heart dose by 40.9% (range 15.0%-57.4%) compared with VMAT. Proton plan robustness to a 3.5% range error was acceptable. For all patients, the clinical target volume D98 was 95.0% to 100.4% of the prescribed dose and gross tumor volume (GTV) D98 was 98.8% to 101%. Setup error robustness was patient anatomy dependent, and the potential minimum dose per fraction was always lower with SFO than with VMAT. The clinical target volume D98 was lower by 0.6% to 7.8% of the prescribed dose, and the GTV D98 was lower by 0.3% to 2.2% of the prescribed GTV dose. The SFO plans achieved significant sparing of normal tissue compared with the VMAT plans for midesophageal cancer. The target dose coverage in the SIB proton plans was less robust to random setup errors and might be unacceptable for certain patients. Robust optimization to ensure adequate target coverage of SIB proton plans might be beneficial. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Qi, S; Kishan, A; Alexander, S
2015-06-15
Purpose: We have observed improved local control probability (LCP) for adjuvant mesothelioma radiotherapy following pleurectomy/decortication using Tomotherapy compared to the conventional 3D technique (p<0.05). This work assesses the correlation between the improved clinical outcomes against dosimetry quantities. Methods: Thirty-eight mesothelioma cases consecutively treated at our clinic were retrospectively analyzed. Sixteen patients were treated using 3D technique planned on the Eclipse for c-arm accelerators prior to 7/2012; the other 22 cases were treated on Tomotherapy using helical IMRT after 7/2012. Typical 3D plans consisting of 15 MV AP/PA photon fields prescribed to 10 cm depth followed by matching electron fields withmore » energy ranging from 8–16 MeV. Tomotherapy plans were designed using 2.5cm jaw, 0.287 pitch with directional blocking of the contralateral lung. The same prescription of 45 Gy (1.8GyX25) was used for both techniques. The dosimetry metrics for the critical structures: ipsilateral-/contralateral-lung, heart, cord, esophagus, etc were compared between two techniques. Results: Superior LCP is closely associated with improved target coverage. Tomotherapy plans yielded dramatically better target coverage and less dose heterogeneity despite of more advanced/larger disease. The averaged PTV volumes were 2287.3±569.9 (Tomotherapy) vs. 1904.8±312.3cc (3D); V100s were: 91.1±4.0 (%) vs. 47.8±12.7 (%) with heterogeneity indices of 1.20±0.1 vs.1.37±0.38 and for the Tomotherapy and 3D plans, respectively. Compared to the 3D technique, we observed significant lower maximum cord doses (p<0.001), lower mean esophagus doses (p<0.002), and lower heart mean doses when tumor was left-sided (p=0.002). For ipsilateral-/contralateral-lungs, however, the mean doses and V20, V5 of Tomotherapy plans were significantly higher than the 3D plans (p<0.01) regardless which sides of lung were treated. However, rates of radiation pneumonitis were no different. Conclusion: Tomotherapy achieved great improvement of plan quality including target coverage, resulting in significantly better local control over the traditional 3D technique for adjuvant radiotherapy for mesothelioma.« less
Assessing pooled BAC and whole genome shotgun strategies for assembly of complex genomes.
Haiminen, Niina; Feltus, F Alex; Parida, Laxmi
2011-04-15
We investigate if pooling BAC clones and sequencing the pools can provide for more accurate assembly of genome sequences than the "whole genome shotgun" (WGS) approach. Furthermore, we quantify this accuracy increase. We compare the pooled BAC and WGS approaches using in silico simulations. Standard measures of assembly quality focus on assembly size and fragmentation, which are desirable for large whole genome assemblies. We propose additional measures enabling easy and visual comparison of assembly quality, such as rearrangements and redundant sequence content, relative to the known target sequence. The best assembly quality scores were obtained using 454 coverage of 15× linear and 5× paired (3kb insert size) reads (15L-5P) on Arabidopsis. This regime gave similarly good results on four additional plant genomes of very different GC and repeat contents. BAC pooling improved assembly scores over WGS assembly, coverage and redundancy scores improving the most. BAC pooling works better than WGS, however, both require a physical map to order the scaffolds. Pool sizes up to 12Mbp work well, suggesting this pooling density to be effective in medium-scale re-sequencing applications such as targeted sequencing of QTL intervals for candidate gene discovery. Assuming the current Roche/454 Titanium sequencing limitations, a 12 Mbp region could be re-sequenced with a full plate of linear reads and a half plate of paired-end reads, yielding 15L-5P coverage after read pre-processing. Our simulation suggests that massively over-sequencing may not improve accuracy. Our scoring measures can be used generally to evaluate and compare results of simulated genome assemblies.
Rahman, Md Shafiur; Rahman, Md Mizanur; Gilmour, Stuart; Swe, Khin Thet; Krull Abe, Sarah; Shibuya, Kenji
2018-01-01
Many countries are implementing health system reforms to achieve universal health coverage (UHC) by 2030. To understand the progress towards UHC in Bangladesh, we estimated trends in indicators of the health service and of financial risk protection. We also estimated the probability of Bangladesh's achieving of UHC targets of 80% essential health-service coverage and 100% financial risk protection by 2030. We estimated the coverage of UHC indicators-13 prevention indicators and four treatment indicators-from 19 nationally representative population-based household surveys done in Bangladesh from Jan 1, 1991, to Dec 31, 2014. We used a Bayesian regression model to estimate the trend and to predict the coverage of UHC indicators along with the probabilities of achieving UHC targets of 80% coverage of health services and 100% coverage of financial risk protection from catastrophic and impoverishing health payments by 2030. We used the concentration index and relative index of inequality to assess wealth-based inequality in UHC indicators. If the current trends remain unchanged, we estimated that coverage of childhood vaccinations, improved water, oral rehydration treatment, satisfaction with family planning, and non-use of tobacco will achieve the 80% target by 2030. However, coverage of four antenatal care visits, facility-based delivery, skilled birth attendance, postnatal checkups, care seeking for pneumonia, exclusive breastfeeding, non-overweight, and adequate sanitation were not projected to achieve the target. Quintile-specific projections showed wide wealth-based inequality in access to antenatal care, postnatal care, delivery care, adequate sanitation, and care seeking for pneumonia, and this inequality was projected to continue for all indicators. The incidence of catastrophic health expenditure and impoverishment were projected to increase from 17% and 4%, respectively, in 2015, to 20% and 9%, respectively, by 2030. Inequality analysis suggested that wealthiest households would disproportionately face more financial catastrophe than the most disadvantaged households. Despite progress, Bangladesh will not achieve the 2030 UHC targets unless the country scales up interventions related to maternal and child health services, and reforms health financing systems to avoid high dependency on out-of-pocket payments. The introduction of a national health insurance system, increased public funding for health care, and expansion of community-based clinics in rural areas could help to move the country towards UHC. Japan Ministry of Health, Labour, and Welfare. Copyright © 2018 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY-NC-ND 4.0 license. Published by Elsevier Ltd.. All rights reserved.
Massat, Nathalie J; Douglas, Elaine; Waller, Jo; Wardle, Jane; Duffy, Stephen W
2015-01-01
Objectives Reducing cancer screening inequalities in England is a major focus of the 2011 Department of Health cancer outcome strategy. Screening coverage requires regular monitoring in order to implement targeted interventions where coverage is low. This study aimed to characterise districts with atypical coverage levels for cervical or breast screening. Design Observational study of district-level coverage in the English Cervical and Breast screening programmes in 2012. Setting England, UK. Participants All English women invited to participate in the cervical (age group 25–49 and 50–64) and breast (age group 50–64) screening programmes. Outcomes Risk adjustment models for coverage were developed based on district-level characteristics. Funnel plots of adjusted coverage were constructed, and atypical districts examined by correlation analysis. Results Variability in coverage was primarily explained by population factors, whereas general practice characteristics had little independent effect. Deprivation and ethnicity other than white, Asian, black or mixed were independently associated with poorer coverage in both screening programmes, with ethnicity having the strongest effect; by comparison, the influence of Asian, black or mixed ethnic minority was limited. Deprivation, ethnicity and urbanisation largely accounted for the lower cervical screening coverage in London. However, for breast screening, being located in London remained a strong negative predictor. A subset of districts was identified as having atypical coverage across programmes. Correlates of deprivation in districts with relatively low adjusted coverage were substantially different from overall correlates of deprivation. Discussion These results inform the continuing drive to reduce avoidable cancer deaths in England, and encourage implementation of targeted interventions in communities residing in districts identified as having atypically low coverage. Sequential implementation to monitor the impact of local interventions would help accrue evidence on ‘what works’. PMID:26209119
Assessment of PlanIQ Feasibility DVH for head and neck treatment planning.
Fried, David V; Chera, Bhishamjit S; Das, Shiva K
2017-09-01
Designing a radiation plan that optimally delivers both target coverage and normal tissue sparing is challenging. There are limited tools to determine what is dosimetrically achievable and frequently the experience of the planner/physician is relied upon to make these determinations. PlanIQ software provides a tool that uses target and organ at risk (OAR) geometry to indicate the difficulty of achieving different points for organ dose-volume histograms (DVH). We hypothesized that PlanIQ Feasibility DVH may aid planners in reducing dose to OARs. Clinically delivered head and neck treatments (clinical plan) were re-planned (re-plan) putting high emphasis on maximally sparing the contralateral parotid gland, contralateral submandibular gland, and larynx while maintaining routine clinical dosimetric objectives. The planner was blinded to the results of the clinically delivered plan as well as the Feasibility DVHs from PlanIQ. The re-plan treatments were designed using 3-arc VMAT in Raystation (RaySearch Laboratories, Sweden). The planner was then given the results from the PlanIQ Feasibility DVH analysis and developed an additional plan incorporating this information using 4-arc VMAT (IQ plan). The DVHs across the three treatment plans were compared with what was deemed "impossible" by PlanIQ's Feasibility DVH (Impossible DVH). The impossible DVH (red) is defined as the DVH generated using the minimal dose that any voxel outside the targets must receive given 100% target coverage. The re-plans performed blinded to PlanIQ Feasibilty DVH achieved superior sparing of aforementioned OARs compared to the clinically delivered plans and resulted in discrepancies from the impossible DVHs by an average of 200-700 cGy. Using the PlanIQ Feasibility DVH led to additionalOAR sparing compared to both the re-plans and clinical plans and reduced the discrepancies from the impossible DVHs to an average of approximately 100 cGy. The dose reduction from clinical to re-plan and re-plan to IQ plan were significantly different even when taking into account multiple hypothesis testing for both the contralateral parotid and the larynx (P < 0.004 for all comparisons). No significant differences were observed between the three plans for the contralateral parotid when considering multiple hypothesis testing. Clinical treatment plans and blinded re-plans were found to suboptimally spare OARs. PlanIQ could aid planners in generating treatment plans that push the limits of OAR sparing while maintaining routine clinical target coverage goals. © 2017 The Authors. Journal of Applied Clinical Medical Physics published by Wiley Periodicals, Inc. on behalf of American Association of Physicists in Medicine.
NASA Astrophysics Data System (ADS)
Poulet, L.; Massa, G. D.; Morrow, R. C.; Bourget, C. M.; Wheeler, R. M.; Mitchell, C. A.
2014-07-01
Bioregenerative life-support systems involving photoautotrophic organisms will be necessary to sustain long-duration crewed missions at distant space destinations. Since sufficient sunlight will not always be available for plant growth at many space destinations, efficient electric-lighting solutions are greatly needed. The present study demonstrated that targeted plant lighting with light-emitting diodes (LEDs) and optimizing spectral parameters for close-canopy overhead LED lighting allowed the model crop leaf lettuce (Lactuca sativa L. cv. 'Waldmann's Green') to be grown using significantly less electrical energy than using traditional electric-lighting sources. Lettuce stands were grown hydroponically in a growth chamber controlling temperature, relative humidity, and CO2 level. Several red:blue ratios were tested for growth rate during the lag phase of lettuce growth. In addition, start of the exponential growth phase was evaluated. Following establishment of a 95% red + 5% blue spectral balance giving the best growth response, the energy efficiency of a targeted lighting system was compared with that of two total coverage (untargeted) LED lighting systems throughout a crop-production cycle, one using the same proportion of red and blue LEDs and the other using white LEDs. At the end of each cropping cycle, whole-plant fresh and dry mass and leaf area were measured and correlated with the amount of electrical energy (kWh) consumed for crop lighting. Lettuce crops grown with targeted red + blue LED lighting used 50% less energy per unit dry biomass accumulated, and the total coverage white LEDs used 32% less energy per unit dry biomass accumulated than did the total coverage red + blue LEDs. An energy-conversion efficiency of less than 1 kWh/g dry biomass is possible using targeted close-canopy LED lighting with spectral optimization. This project was supported by NASA grant NNX09AL99G.
Leung, Lucullus H.T.; Yu, Peter K.N.
2013-01-01
A new version of progressive resolution optimizer (PRO) with an option of air cavity correction has been implemented for RapidArc volumetric‐modulated arc therapy (RA). The purpose of this study was to compare the performance of this new PRO with the use of air cavity correction option (PRO10_air) against the one without the use of the air cavity correction option (PRO10_no‐air) for RapidArc planning in targets with low‐density media of different sizes and complexities. The performance of PRO10_no‐air and PRO10_air was initially compared using single‐arc plans created for four different simple heterogeneous phantoms with virtual targets and organs at risk. Multiple‐arc planning of 12 real patients having nasopharyngeal carcinomas (NPC) and ten patients having non‐small cell lung cancer (NSCLC) were then performed using the above two options for further comparison. Dose calculations were performed using both the Acuros XB (AXB) algorithm with the dose to medium option and the analytical anisotropic algorithm (AAA). The effect of using intermediate dose option after the first optimization cycle in PRO10_air and PRO10_no‐air was also investigated and compared. Plans were evaluated and compared using target dose coverage, critical organ sparing, conformity index, and dose homogeneity index. For NSCLC cases or cases for which large volumes of low‐density media were present in or adjacent to the target volume, the use of the air cavity correction option in PROIO was shown to be beneficial. For NPC cases or cases for which small volumes of both low‐ and high‐density media existed in the target volume, the use of air cavity correction in PRO10 did not improve the plan quality. Based on the AXB dose calculation results, the use of PRO10_air could produce up to 18% less coverage to the bony structures of the planning target volumes for NPC cases. When the intermediate dose option in PRO10 was used, there was negligible difference observed in plan quality between optimizations with and without using the air cavity correction option. PACS number: 87.55.D‐, 87.55.de, 87.56.N‐
DOE Office of Scientific and Technical Information (OSTI.GOV)
Ming, X; Zhang, Y; Yale University, New Haven, CT, US
2014-06-01
Purpose: The cardiac toxicity for lung cancer patients, each treated with dynamic conformal arc therapy (DAT), intensity-modulated radiation therapy (IMRT), or volumetric modulated arc therapy (VMAT) is investigated. Methods: 120 lung patients were selected for this study: 25 treated with DAT, 50 with IMRT and 45 with VMAT. For comparison, all plans were generated in the same treatment planning system, normalized such that the 100% isodose lines encompassed 95% of planning target volume. The plan quality was evaluated in terms of homogeneity index (HI) and 95% conformity index (%95 CI) for target dose coverage and mean dose, maximum dose, V{submore » 30} Gy as well as V{sub 5} Gy for cardiac toxicity analysis. Results: When all the plans were analyzed, the VMAT plans offered the best target coverage with 95% CI = 0.992 and HI = 1.23. The DAT plans provided the best heart sparing with mean heart dose = 2.3Gy and maximum dose = 11.6Gy, as compared to 5.7 Gy and 31.1 Gy by IMRT as well as 4.6 Gy and 30.9 Gy by VMAT. The mean V30Gy and V5Gy of the heart in the DAT plans were up to 11.7% lower in comparison to the IMRT and VMAT plans. When the tumor volume was considered, the VMAT plans spared up to 70.9% more doses to the heart when the equivalent diameter of the tumor was larger than 4cm. Yet the maximum dose to the heart was reduced the most in the DAT plans with up to 139.8% less than that of the other two plans. Conclusion: Overall, the VMAT plans achieved the best target coverage among the three treatment modalities, and would spare the heart the most for the larger tumors. The DAT plans appeared advantageous in delivering the least maximum dose to the heart as compared to the IMRT and VMAT plans.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Masi, K; Ditman, M; Marsh, R
Purpose: There is potentially a wide variation in plan quality for a certain disease site, even for clinics located in the same system of hospitals. We have used a prostate-specific knowledge-based planning (KBP) model as a quality control tool to investigate the variation in prostate treatment planning across a network of affiliated radiation oncology departments. Methods: A previously created KBP model was applied to 10 patients each from 4 community-based clinics (Clinics A, B, C, and D). The KBP model was developed using RapidPlan (Eclipse v13.5, Varian Medical Systems) from 60 prostate/prostate bed IMRT plans that were originally planned usingmore » an in-house treatment planning system at the central institution of the community-based clinics. The dosimetric plan quality (target coverage and normal-tissue sparing) of each model-generated plan was compared to the respective clinically-used plan. Each community-based clinic utilized the same planning goals to develop the clinically-used plans that were used at the main institution. Results: Across all 4 clinics, the model-generated plans decreased the mean dose to the rectum by varying amounts (on average, 12.5, 2.6, 4.5, and 2.7 Gy for Clinics A, B, C, and D, respectively). The mean dose to the bladder also decreased with the model-generated plans (5.4, 2.3, 3.0, and 4.1 Gy, respectively). The KBP model also identified that target coverage (D95%) improvements were possible for for Clinics A, B, and D (0.12, 1.65, and 2.75%) while target coverage decreased by 0.72% for Clinic C, demonstrating potentially different trade-offs made in clinical plans at different institutions. Conclusion: Quality control of dosimetric plan quality across a system of radiation oncology practices is possible with knowledge-based planning. By using a quality KBP model, smaller community-based clinics can potentially identify the areas of their treatment plans that may be improved, whether it be in normal-tissue sparing or improved target coverage. M. Matuszak has research funding for KBP from Varian Medical Systems.« less
Chi, F; Wu, S; Zhou, J; Li, F; Sun, J; Lin, Q; Lin, H; Guan, X; He, Z
2015-05-01
This study determined the dosimetric comparison of moderate deep inspiration breath-hold using active breathing control and free-breathing intensity-modulated radiotherapy (IMRT) after breast-conserving surgery for left-sided breast cancer. Thirty-one patients were enrolled. One free breathe and two moderate deep inspiration breath-hold images were obtained. A field-in-field-IMRT free-breathing plan and two field-in-field-IMRT moderate deep inspiration breath-holding plans were compared in the dosimetry to target volume coverage of the glandular breast tissue and organs at risks for each patient. The breath-holding time under moderate deep inspiration extended significantly after breathing training (P<0.05). There was no significant difference between the free-breathing and moderate deep inspiration breath-holding in the target volume coverage. The volume of the ipsilateral lung in the free-breathing technique were significantly smaller than the moderate deep inspiration breath-holding techniques (P<0.05); however, there was no significant difference between the two moderate deep inspiration breath-holding plans. There were no significant differences in target volume coverage between the three plans for the field-in-field-IMRT (all P>0.05). The dose to ipsilateral lung, coronary artery and heart in the field-in-field-IMRT were significantly lower for the free-breathing plan than for the two moderate deep inspiration breath-holding plans (all P<0.05); however, there was no significant difference between the two moderate deep inspiration breath-holding plans. The whole-breast field-in-field-IMRT under moderate deep inspiration breath-hold with active breathing control after breast-conserving surgery in left-sided breast cancer can reduce the irradiation volume and dose to organs at risks. There are no significant differences between various moderate deep inspiration breath-holding states in the dosimetry of irradiation to the field-in-field-IMRT target volume coverage and organs at risks. Copyright © 2015 Société française de radiothérapie oncologique (SFRO). Published by Elsevier SAS. All rights reserved.
Hybrid adaptive radiotherapy with on-line MRI in cervix cancer IMRT.
Oh, Seungjong; Stewart, James; Moseley, Joanne; Kelly, Valerie; Lim, Karen; Xie, Jason; Fyles, Anthony; Brock, Kristy K; Lundin, Anna; Rehbinder, Henrik; Milosevic, Michael; Jaffray, David; Cho, Young-Bin
2014-02-01
Substantial organ motion and tumor shrinkage occur during radiotherapy for cervix cancer. IMRT planning studies have shown that the quality of radiation delivery is influenced by these anatomical changes, therefore the adaptation of treatment plans may be warranted. Image guidance with off-line replanning, i.e. hybrid-adaptation, is recognized as one of the most practical adaptation strategies. In this study, we investigated the effects of soft tissue image guidance using on-line MR while varying the frequency of off-line replanning on the adaptation of cervix IMRT. 33 cervical cancer patients underwent planning and weekly pelvic MRI scans during radiotherapy. 5 patients of 33 were identified in a previous retrospective adaptive planning study, in which the coverage of gross tumor volume/clinical target volume (GTV/CTV) was not acceptable given single off-line IMRT replan using a 3mm PTV margin with bone matching. These 5 patients and a randomly selected 10 patients from the remaining 28 patients, a total of 15 patients of 33, were considered in this study. Two matching methods for image guidance (bone to bone and soft tissue to dose matrix) and three frequencies of off-line replanning (none, single, and weekly) were simulated and compared with respect to target coverage (cervix, GTV, lower uterus, parametrium, upper vagina, tumor related CTV and elective lymph node CTV) and OAR sparing (bladder, bowel, rectum, and sigmoid). Cost (total process time) and benefit (target coverage) were analyzed for comparison. Hybrid adaptation (image guidance with off-line replanning) significantly enhanced target coverage for both 5 difficult and 10 standard cases. Concerning image guidance, bone matching was short of delivering enough doses for 5 difficult cases even with a weekly off-line replan. Soft tissue image guidance proved successful for all cases except one when single or more frequent replans were utilized in the difficult cases. Cost and benefit analysis preferred (soft tissue) image guidance over (frequent) off-line replanning. On-line MRI based image guidance (with combination of dose distribution) is a crucial element for a successful hybrid adaptive radiotherapy. Frequent off-line replanning adjuvantly enhances adaptation quality. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.
Ogbuanu, Ikechukwu U.; Adegoke, Oluwasegun J.; Scobie, Heather M.; Uba, Belinda V.; Wannemuehler, Kathleen A.; Ruiz, Alicia; Elmousaad, Hashim; Ohuabunwo, Chima J.; Mustafa, Mahmud; Nguku, Patrick; Waziri, Ndadilnasiya Endie; Vertefeuille, John F.
2016-01-01
Background Despite recent success towards controlling poliovirus transmission, Nigeria has struggled to achieve uniformly high routine vaccination coverage. A lack of reliable vaccination coverage data at the operational level makes it challenging to target program improvement. To reliably estimate vaccination coverage, we conducted district-level vaccine coverage surveys using a pre-existing infrastructure of polio technical staff in northern Nigeria. Methods Household-level cluster surveys were conducted in 40 polio high risk districts of Nigeria during 2014–2015. Global positioning system technology and intensive supervision by a pool of qualified technical staff were used to ensure high survey quality. Vaccination status of children aged 12–23 months was documented based on vaccination card or caretaker’s recall. District-level coverage estimates were calculated using survey methods. Results Data from 7,815 children across 40 districts were analyzed. District-level coverage with the third dose of diphtheria-pertussis-tetanus vaccine (DPT3) ranged widely from 1–63%, with all districts having DPT3 coverage below the target of 80%. Median coverage across all districts for each of eight vaccine doses (1 Bacille Calmette-Guérin dose, 3 DPT doses, 3 oral poliovirus vaccine doses, and 1 measles vaccine dose) was <50%. DPT3 coverage by survey was substantially lower (range: 28%–139%) than the 2013 administrative coverage reported among children aged <12 months. Common reported reasons for non-vaccination included lack of knowledge about vaccines and vaccination services (50%) and factors related to access to routine immunization services (15%). Conclusions Survey results highlighted vaccine coverage gaps that were systematically underestimated by administrative reporting across 40 polio high risk districts in northern Nigeria. Given the limitations of administrative coverage data, our approach to conducting quality district-level coverage surveys and providing data to assess and remediate issues contributing to poor vaccination coverage could serve as an example in countries with sub-optimal vaccination coverage, similar to Nigeria. PMID:27936077
Gunnala, Rajni; Ogbuanu, Ikechukwu U; Adegoke, Oluwasegun J; Scobie, Heather M; Uba, Belinda V; Wannemuehler, Kathleen A; Ruiz, Alicia; Elmousaad, Hashim; Ohuabunwo, Chima J; Mustafa, Mahmud; Nguku, Patrick; Waziri, Ndadilnasiya Endie; Vertefeuille, John F
2016-01-01
Despite recent success towards controlling poliovirus transmission, Nigeria has struggled to achieve uniformly high routine vaccination coverage. A lack of reliable vaccination coverage data at the operational level makes it challenging to target program improvement. To reliably estimate vaccination coverage, we conducted district-level vaccine coverage surveys using a pre-existing infrastructure of polio technical staff in northern Nigeria. Household-level cluster surveys were conducted in 40 polio high risk districts of Nigeria during 2014-2015. Global positioning system technology and intensive supervision by a pool of qualified technical staff were used to ensure high survey quality. Vaccination status of children aged 12-23 months was documented based on vaccination card or caretaker's recall. District-level coverage estimates were calculated using survey methods. Data from 7,815 children across 40 districts were analyzed. District-level coverage with the third dose of diphtheria-pertussis-tetanus vaccine (DPT3) ranged widely from 1-63%, with all districts having DPT3 coverage below the target of 80%. Median coverage across all districts for each of eight vaccine doses (1 Bacille Calmette-Guérin dose, 3 DPT doses, 3 oral poliovirus vaccine doses, and 1 measles vaccine dose) was <50%. DPT3 coverage by survey was substantially lower (range: 28%-139%) than the 2013 administrative coverage reported among children aged <12 months. Common reported reasons for non-vaccination included lack of knowledge about vaccines and vaccination services (50%) and factors related to access to routine immunization services (15%). Survey results highlighted vaccine coverage gaps that were systematically underestimated by administrative reporting across 40 polio high risk districts in northern Nigeria. Given the limitations of administrative coverage data, our approach to conducting quality district-level coverage surveys and providing data to assess and remediate issues contributing to poor vaccination coverage could serve as an example in countries with sub-optimal vaccination coverage, similar to Nigeria.
Change-Based Satellite Monitoring Using Broad Coverage and Targetable Sensing
NASA Technical Reports Server (NTRS)
Chien, Steve A.; Tran, Daniel Q.; Doubleday, Joshua R.; Doggett, Thomas
2013-01-01
A generic software framework analyzes data from broad coverage sweeps or general larger areas of interest. Change detection methods are used to extract subsets of directed swath areas that intersect areas of change. These areas are prioritized and allocated to targetable assets. This method is deployed in an automatic fashion, and has operated without human monitoring or intervention for sustained periods of time (months).
Nicolini, G; Abraham, S; Fogliata, A; Jordaan, A; Clivio, A; Vanetti, E; Cozzi, L
2013-03-01
To evaluate the use of volumetric-modulated arc therapy [VMAT, RapidArc® (RA); Varian Medical Systems, Palo Alto, CA] for the treatment of cutaneous Kaposi's sarcoma (KS) of lower extremities with adequate target coverage and high bone sparing, and to compare VMAT with electron beam therapy. 10 patients were planned with either RA or electron beams. The dose was prescribed to 30 Gy, 10 fractions, to mean the planning target volume (PTV), and significant maximum dose to bone was limited to 30 Gy. Plans were designed for 6-MV photon beams for RA and 6 MeV for electrons. Dose distributions were computed with AcurosXB® (Varian Medical Systems) for photons and with a Monte Carlo algorithm for electrons. V(90%) was 97.3±1.2 for RA plans and 78.2±2.6 for electrons; similarly, V(107%) was 2.5±2.2 and 37.7±3.4, respectively. RA met coverage criteria. Concerning bone sparing, D(2%) was 29.6±1.1 for RA and 31.0±2.4 for electrons. Although acceptable for bone involvement, pronounced target coverage violations were obtained for electron plans. Monitor units were similar for electrons and RA, although for the latter they increased when superior bone sparing was imposed. Delivery times were 12.1±4.0 min for electrons and 4.8±1.3 min for the most modulated RA plans. High plan quality was shown for KS in the lower extremities using VMAT, and this might simplify their management in comparison with the more conventional usage of electrons, particularly in institutes with limited staff resources and heavy workloads. VMAT is also dosimetrically extremely advantageous in a typology of treatments where electron beam therapy is mainly considered to be effective owing to the limited penetration of the beams.
Media framing and political advertising in the Patients' Bill of Rights debate.
Rabinowitz, Aaron
2010-10-01
The purpose of this article is to assess the influence of interest groups over news content. In particular, I explore the possibility that political advertising campaigns affect the tenor and framing of newspaper coverage in health policy debates. To do so, I compare newspaper coverage of the Patients' Bill of Rights debate in 1999 in five states that were subject to extensive advertising campaigns with coverage in five comparison states that were not directly exposed to the advocacy campaigns. I find significant differences in coverage depending on the presence or absence of paid advertising campaigns, and conclude that readers were exposed to different perspectives and arguments about managed care regulation if the newspapers they read were published in states targeted by political advertisements. Specifically, newspaper coverage was 17 percent less likely to be supportive of managed care reform in states subject to advertising campaigns designed to foment opposition to the Patients' Bill of Rights. Understanding the ability of organized interests and political actors to successfully promote their preferred issue frames in a dynamic political environment is particularly important in light of the proliferation of interest groups, the prevalence of multimillion-dollar political advertising campaigns, and the health care reform debate under President Barack Obama.
Gilardi, Francesco; Castelli Gattinara, Guido; Vinci, Maria Rosaria; Ciofi Degli Atti, Marta; Santilli, Veronica; Brugaletta, Rita; Santoro, Annapaola; Montanaro, Rosina; Lavorato, Luisa; Raponi, Massimiliano; Zaffina, Salvatore
2018-04-24
Despite relevant recommendations and evidences on the efficacy of influenza vaccination in health care workers (HCWs), vaccination coverage rates in Europe and Italy currently do not exceed 25%. Aim of the study is to measure the variations in vaccination coverage rates in an Italian pediatric hospital after a promotion campaign performed in the period October⁻December 2017. The design is a pre-post intervention study. The intervention is based on a wide communication campaign and an expanded offer of easy vaccination on site. The study was carried out at Bambino Gesù Children’s hospital in Rome, Italy, on the whole population of HCWs. Univariate and multivariate statistical analyses were performed. Vaccination coverage rate increased in 2017/18 campaign compared with the 2016/17 one (+95 HCWs vaccinated; +4.4%). The highest increases were detected in males (+45.7%), youngest employees (+142.9%), mean age of employment (+175%), other HCWs (+209.1%), Emergency Area (+151.6%) and Imaging Diagnostic Department (+200.0%). At multivariate logistic regression, working in some departments and being nurses represents a higher risk of being unvaccinated. Although the vaccination coverage rate remained low, a continuous increase of the coverage rate and development of a different consciousness in HCWs was highlighted. The study significantly identified the target for future campaigns.
Volumetric modulated arc therapy vs. IMRT for the treatment of distal esophageal cancer.
Van Benthuysen, Liam; Hales, Lee; Podgorsak, Matthew B
2011-01-01
Several studies have demonstrated that volumetric modulated arc therapy (VMAT) has the ability to reduce monitor units and treatment time when compared with intensity-modulated radiation therapy (IMRT). This study aims to demonstrate that VMAT is able to provide adequate organs at risk (OAR) sparing and planning target volume (PTV) coverage for adenocarcinoma of the distal esophagus while reducing monitor units and treatment time. Fourteen patients having been treated previously for esophageal cancer were planned using both VMAT and IMRT techniques. Dosimetric quality was evaluated based on doses to several OARs, as well as coverage of the PTV. Treatment times were assessed by recording the number of monitor units required for dose delivery. Body V(5) was also recorded to evaluate the increased volume of healthy tissue irradiated to low doses. Dosimetric differences in OAR sparing between VMAT and IMRT were comparable. PTV coverage was similar for the 2 techniques but it was found that IMRT was capable of delivering a slightly more homogenous dose distribution. Of the 14 patients, 12 were treated with a single arc and 2 were treated with a double arc. Single-arc plans reduced monitor units by 42% when compared with the IMRT plans. Double-arc plans reduced monitor units by 67% when compared with IMRT. The V(5) for the body was found to be 18% greater for VMAT than for IMRT. VMAT has the capability to decrease treatment times over IMRT while still providing similar OAR sparing and PTV coverage. Although there will be a smaller risk of patient movement during VMAT treatments, this advantage comes at the cost of delivering small doses to a greater volume of the patient. Copyright © 2011 American Association of Medical Dosimetrists. Published by Elsevier Inc. All rights reserved.
Shih, Ya-Chen Tina; Xu, Ying; Liu, Lei; Smieliauskas, Fabrice
2017-08-01
Purpose The high cost of oncology drugs threatens the affordability of cancer care. Previous research identified drivers of price growth of targeted oral anticancer medications (TOAMs) in private insurance plans and projected the impact of closing the coverage gap in Medicare Part D in 2020. This study examined trends in TOAM prices and patient out-of-pocket (OOP) payments in Medicare Part D and estimated the actual effects on patient OOP payments of partial filling of the coverage gap by 2012. Methods Using SEER linked to Medicare Part D, 2007 to 2012, we identified patients who take TOAMs via National Drug Codes in Part D claims. We calculated total drug costs (prices) and OOP payments per patient per month and compared their rates of inflation with general health care prices. Results The study cohort included 42,111 patients who received TOAMs between 2007 and 2012. Although the general prescription drug consumer price index grew at 3% per year over 2007 to 2012, mean TOAM prices increased by nearly 12% per year, reaching $7,719 per patient per month in 2012. Prices increased over time for newly and previously launched TOAMs. Mean patient OOP payments dropped by 4% per year over the study period, with a 40% drop among patients with a high financial burden in 2011, when the coverage gap began to close. Conclusion Rising TOAM prices threaten the financial relief patients have begun to experience under closure of the coverage gap in Medicare Part D. Policymakers should explore methods of harnessing the surge of novel TOAMs to increase price competition for Medicare beneficiaries.
Spot Weight Adaptation for Moving Target in Spot Scanning Proton Therapy.
Morel, Paul; Wu, Xiaodong; Blin, Guillaume; Vialette, Stéphane; Flynn, Ryan; Hyer, Daniel; Wang, Dongxu
2015-01-01
This study describes a real-time spot weight adaptation method in spot-scanning proton therapy for moving target or moving patient, so that the resultant dose distribution closely matches the planned dose distribution. The method proposed in this study adapts the weight (MU) of the delivering pencil beam to that of the target spot; it will actually hit during patient/target motion. The target spot that a certain delivering pencil beam may hit relies on patient monitoring and/or motion modeling using four-dimensional (4D) CT. After the adapted delivery, the required total weight [Monitor Unit (MU)] for this target spot is then subtracted from the planned value. With continuous patient motion and continuous spot scanning, the planned doses to all target spots will eventually be all fulfilled. In a proof-of-principle test, a lung case was presented with realistic temporal and motion parameters; the resultant dose distribution using spot weight adaptation was compared to that without using this method. The impact of the real-time patient/target position tracking or prediction was also investigated. For moderate motion (i.e., mean amplitude 0.5 cm), D95% to the planning target volume (PTV) was only 81.5% of the prescription (RX) dose; with spot weight adaptation PTV D95% achieves 97.7% RX. For large motion amplitude (i.e., 1.5 cm), without spot weight adaptation PTV D95% is only 42.9% of RX; with spot weight adaptation, PTV D95% achieves 97.7% RX. Larger errors in patient/target position tracking or prediction led to worse final target coverage; an error of 3 mm or smaller in patient/target position tracking is preferred. The proposed spot weight adaptation method was able to deliver the planned dose distribution and maintain target coverage when patient motion was involved. The successful implementation of this method would rely on accurate monitoring or prediction of patient/target motion.
Lionel, Anath C; Costain, Gregory; Monfared, Nasim; Walker, Susan; Reuter, Miriam S; Hosseini, S Mohsen; Thiruvahindrapuram, Bhooma; Merico, Daniele; Jobling, Rebekah; Nalpathamkalam, Thomas; Pellecchia, Giovanna; Sung, Wilson W L; Wang, Zhuozhi; Bikangaga, Peter; Boelman, Cyrus; Carter, Melissa T; Cordeiro, Dawn; Cytrynbaum, Cheryl; Dell, Sharon D; Dhir, Priya; Dowling, James J; Heon, Elise; Hewson, Stacy; Hiraki, Linda; Inbar-Feigenberg, Michal; Klatt, Regan; Kronick, Jonathan; Laxer, Ronald M; Licht, Christoph; MacDonald, Heather; Mercimek-Andrews, Saadet; Mendoza-Londono, Roberto; Piscione, Tino; Schneider, Rayfel; Schulze, Andreas; Silverman, Earl; Siriwardena, Komudi; Snead, O Carter; Sondheimer, Neal; Sutherland, Joanne; Vincent, Ajoy; Wasserman, Jonathan D; Weksberg, Rosanna; Shuman, Cheryl; Carew, Chris; Szego, Michael J; Hayeems, Robin Z; Basran, Raveen; Stavropoulos, Dimitri J; Ray, Peter N; Bowdin, Sarah; Meyn, M Stephen; Cohn, Ronald D; Scherer, Stephen W; Marshall, Christian R
2018-01-01
Purpose Genetic testing is an integral diagnostic component of pediatric medicine. Standard of care is often a time-consuming stepwise approach involving chromosomal microarray analysis and targeted gene sequencing panels, which can be costly and inconclusive. Whole-genome sequencing (WGS) provides a comprehensive testing platform that has the potential to streamline genetic assessments, but there are limited comparative data to guide its clinical use. Methods We prospectively recruited 103 patients from pediatric non-genetic subspecialty clinics, each with a clinical phenotype suggestive of an underlying genetic disorder, and compared the diagnostic yield and coverage of WGS with those of conventional genetic testing. Results WGS identified diagnostic variants in 41% of individuals, representing a significant increase over conventional testing results (24% P = 0.01). Genes clinically sequenced in the cohort (n = 1,226) were well covered by WGS, with a median exonic coverage of 40 × ±8 × (mean ±SD). All the molecular diagnoses made by conventional methods were captured by WGS. The 18 new diagnoses made with WGS included structural and non-exonic sequence variants not detectable with whole-exome sequencing, and confirmed recent disease associations with the genes PIGG, RNU4ATAC, TRIO, and UNC13A. Conclusion WGS as a primary clinical test provided a higher diagnostic yield than conventional genetic testing in a clinically heterogeneous cohort. PMID:28771251
Lionel, Anath C; Costain, Gregory; Monfared, Nasim; Walker, Susan; Reuter, Miriam S; Hosseini, S Mohsen; Thiruvahindrapuram, Bhooma; Merico, Daniele; Jobling, Rebekah; Nalpathamkalam, Thomas; Pellecchia, Giovanna; Sung, Wilson W L; Wang, Zhuozhi; Bikangaga, Peter; Boelman, Cyrus; Carter, Melissa T; Cordeiro, Dawn; Cytrynbaum, Cheryl; Dell, Sharon D; Dhir, Priya; Dowling, James J; Heon, Elise; Hewson, Stacy; Hiraki, Linda; Inbar-Feigenberg, Michal; Klatt, Regan; Kronick, Jonathan; Laxer, Ronald M; Licht, Christoph; MacDonald, Heather; Mercimek-Andrews, Saadet; Mendoza-Londono, Roberto; Piscione, Tino; Schneider, Rayfel; Schulze, Andreas; Silverman, Earl; Siriwardena, Komudi; Snead, O Carter; Sondheimer, Neal; Sutherland, Joanne; Vincent, Ajoy; Wasserman, Jonathan D; Weksberg, Rosanna; Shuman, Cheryl; Carew, Chris; Szego, Michael J; Hayeems, Robin Z; Basran, Raveen; Stavropoulos, Dimitri J; Ray, Peter N; Bowdin, Sarah; Meyn, M Stephen; Cohn, Ronald D; Scherer, Stephen W; Marshall, Christian R
2018-04-01
PurposeGenetic testing is an integral diagnostic component of pediatric medicine. Standard of care is often a time-consuming stepwise approach involving chromosomal microarray analysis and targeted gene sequencing panels, which can be costly and inconclusive. Whole-genome sequencing (WGS) provides a comprehensive testing platform that has the potential to streamline genetic assessments, but there are limited comparative data to guide its clinical use.MethodsWe prospectively recruited 103 patients from pediatric non-genetic subspecialty clinics, each with a clinical phenotype suggestive of an underlying genetic disorder, and compared the diagnostic yield and coverage of WGS with those of conventional genetic testing.ResultsWGS identified diagnostic variants in 41% of individuals, representing a significant increase over conventional testing results (24%; P = 0.01). Genes clinically sequenced in the cohort (n = 1,226) were well covered by WGS, with a median exonic coverage of 40 × ±8 × (mean ±SD). All the molecular diagnoses made by conventional methods were captured by WGS. The 18 new diagnoses made with WGS included structural and non-exonic sequence variants not detectable with whole-exome sequencing, and confirmed recent disease associations with the genes PIGG, RNU4ATAC, TRIO, and UNC13A.ConclusionWGS as a primary clinical test provided a higher diagnostic yield than conventional genetic testing in a clinically heterogeneous cohort.
NASA Astrophysics Data System (ADS)
Ödén, Jakob; Toma-Dasu, Iuliana; Yu, Cedric X.; Feigenberg, Steven J.; Regine, William F.; Mutaf, Yildirim D.
2013-07-01
The GammaPod™ device, manufactured by Xcision Medical Systems, is a novel stereotactic breast irradiation device. It consists of a hemispherical source carrier containing 36 Cobalt-60 sources, a tungsten collimator with two built-in collimation sizes, a dynamically controlled patient support table and a breast immobilization cup also functioning as the stereotactic frame for the patient. The dosimetric output of the GammaPod™ was modelled using a Monte Carlo based treatment planning system. For the comparison, three-dimensional (3D) models of commonly used intra-cavitary breast brachytherapy techniques utilizing single lumen and multi-lumen balloon as well as peripheral catheter multi-lumen implant devices were created and corresponding 3D dose calculations were performed using the American Association of Physicists in Medicine Task Group-43 formalism. Dose distributions for clinically relevant target volumes were optimized using dosimetric goals set forth in the National Surgical Adjuvant Breast and Bowel Project Protocol B-39. For clinical scenarios assuming similar target sizes and proximity to critical organs, dose coverage, dose fall-off profiles beyond the target and skin doses at given distances beyond the target were calculated for GammaPod™ and compared with the doses achievable by the brachytherapy techniques. The dosimetric goals within the protocol guidelines were fulfilled for all target sizes and irradiation techniques. For central targets, at small distances from the target edge (up to approximately 1 cm) the brachytherapy techniques generally have a steeper dose fall-off gradient compared to GammaPod™ and at longer distances (more than about 1 cm) the relation is generally observed to be opposite. For targets close to the skin, the relative skin doses were considerably lower for GammaPod™ than for any of the brachytherapy techniques. In conclusion, GammaPod™ allows adequate and more uniform dose coverage to centrally and peripherally located targets with an acceptable dose fall-off and lower relative skin dose than the brachytherapy techniques considered in this study.
2012-01-01
Background To investigate geometric and dosimetric accuracy of frame-less image-guided radiosurgery (IG-RS) for brain metastases. Methods and materials Single fraction IG-RS was practiced in 72 patients with 98 brain metastases. Patient positioning and immobilization used either double- (n = 71) or single-layer (n = 27) thermoplastic masks. Pre-treatment set-up errors (n = 98) were evaluated with cone-beam CT (CBCT) based image-guidance (IG) and were corrected in six degrees of freedom without an action level. CBCT imaging after treatment measured intra-fractional errors (n = 64). Pre- and post-treatment errors were simulated in the treatment planning system and target coverage and dose conformity were evaluated. Three scenarios of 0 mm, 1 mm and 2 mm GTV-to-PTV (gross tumor volume, planning target volume) safety margins (SM) were simulated. Results Errors prior to IG were 3.9 mm ± 1.7 mm (3D vector) and the maximum rotational error was 1.7° ± 0.8° on average. The post-treatment 3D error was 0.9 mm ± 0.6 mm. No differences between double- and single-layer masks were observed. Intra-fractional errors were significantly correlated with the total treatment time with 0.7mm±0.5mm and 1.2mm±0.7mm for treatment times ≤23 minutes and >23 minutes (p<0.01), respectively. Simulation of RS without image-guidance reduced target coverage and conformity to 75% ± 19% and 60% ± 25% of planned values. Each 3D set-up error of 1 mm decreased target coverage and dose conformity by 6% and 10% on average, respectively, with a large inter-patient variability. Pre-treatment correction of translations only but not rotations did not affect target coverage and conformity. Post-treatment errors reduced target coverage by >5% in 14% of the patients. A 1 mm safety margin fully compensated intra-fractional patient motion. Conclusions IG-RS with online correction of translational errors achieves high geometric and dosimetric accuracy. Intra-fractional errors decrease target coverage and conformity unless compensated with appropriate safety margins. PMID:22531060
From the parents' perspective: a user-satisfaction survey of immunization services in Guatemala.
Barrera, Lissette; Trumbo, Silas Pierson; Bravo-Alcántara, Pamela; Velandia-González, Martha; Danovaro-Holliday, M Carolina
2014-03-06
Immunization coverage levels in Guatemala have increased over the last two decades, but national targets of ≥95% have yet to be reached. To determine factors related to undervaccination, Guatemala's National Immunization Program conducted a user-satisfaction survey of parents and guardians of children aged 0-5 years. Variables evaluated included parental immunization attitudes, preferences, and practices; the impact of immunization campaigns and marketing strategies; and factors inhibiting immunization. Based on administrative coverage levels and socio-demographic indicators in Guatemala's 22 geographical departments, five were designated as low-coverage and five as high-coverage areas. Overall, 1194 parents and guardians of children aged 0-5 years were interviewed in these 10 departments. We compared indicators between low- and high-coverage areas and identified risk factors associated with undervaccination. Of the 1593 children studied, 29 (1.8%) were determined to be unvaccinated, 458 (28.8%) undervaccinated, and 1106 (69.4%) fully vaccinated. In low-coverage areas, children of less educated (no education: RR=1.49, p=0.01; primary or less: 1.39, p=0.009), older (aged>39 years: RR=1.31, p=0.05), and single (RR=1.32, p=0.03) parents were more likely to have incomplete vaccination schedules. Similarly, factors associated with undervaccination in high-coverage areas included the caregiver's lack of education (none: RR=1.72, p=0.0007; primary or less: RR=1.30, p=0.05) and single marital status (RR=1.36, p=0.03), as well as the child's birth order (second: RR=1.68, p=0.003). Although users generally approved of immunization services, problems in service quality were identified. According to participants, topics such as the risk of adverse events (47.4%) and next vaccination appointments (32.3%) were inconsistently communicated to parents. Additionally, 179 (15.0%) participants reported the inability to vaccinate their child on at least one occasion. Compared to high-coverage areas, participants in low-coverage areas reported poorer service, longer wait times, and greater distances to health centers. In high-coverage areas, participants reported less knowledge about the availability of services. Generally, immunization barriers in Guatemala are related to problems in accessing and attaining high-quality immunization services rather than to a population that does not adequately value vaccination. We provide recommendations to aid the country in maintaining its achievements and addressing new challenges.
ON THE BENEFITS AND RISKS OF PROTON THERAPY IN PEDIATRIC CRANIOPHARYNGIOMA
Beltran, Chris; Roca, Monica; Merchant, Thomas E.
2013-01-01
Purpose Craniopharyngioma is a pediatric brain tumor whose volume is prone to change during radiation therapy. We compared photon- and proton-based irradiation methods to determine the effect of tumor volume change on target coverage and normal tissue irradiation in these patients. Methods and Materials For this retrospective study, we acquired imaging and treatment-planning data from 14 children with craniopharyngioma (mean age, 5.1 years) irradiated with photons (54 Gy) and monitored by weekly magnetic resonance imaging (MRI) examinations during radiation therapy. Photon intensity-modulated radiation therapy (IMRT), double-scatter proton (DSP) therapy, and intensity-modulated proton therapy (IMPT) plans were created for each patient based on his or her pre-irradiation MRI. Target volumes were contoured on each weekly MRI scan for adaptive modeling. The measured differences in conformity index (CI) and normal tissue doses, including functional sub-volumes of the brain, were compared across the planning methods, as was target coverage based on changes in target volumes during treatment. Results CI and normal tissue dose values of IMPT plans were significantly better than those of the IMRT and DSP plans (p < 0.01). Although IMRT plans had a higher CI and lower optic nerve doses (p < 0.01) than did DSP plans, DSP plans had lower cochlear, optic chiasm, brain, and scanned body doses (p < 0.01). The mean planning target volume (PTV) at baseline was 54.8 cm3, and the mean increase in PTV was 11.3% over the course of treatment. The dose to 95% of the PTV was correlated with a change in the PTV; the R2 values for all models, 0.73 (IMRT), 0.38 (DSP), and 0.62 (IMPT), were significant (p < 0.01). Conclusions Compared with photon IMRT, proton therapy has the potential to significantly reduce whole-brain and -body irradiation in pediatric patients with craniopharyngioma. IMPT is the most conformal method and spares the most normal tissue; however, it is highly sensitive to target volume changes, whereas the DSP method is not. PMID:21570209
Lu, Jia-Yang; Cheung, Michael Lok-Man; Huang, Bao-Tian; Wu, Li-Li; Xie, Wen-Jia; Chen, Zhi-Jian; Li, De-Rui; Xie, Liang-Xi
2015-01-01
To assess the performance of a simple optimisation method for improving target coverage and organ-at-risk (OAR) sparing in intensity-modulated radiotherapy (IMRT) for cervical oesophageal cancer. For 20 selected patients, clinically acceptable original IMRT plans (Original plans) were created, and two optimisation methods were adopted to improve the plans: 1) a base dose function (BDF)-based method, in which the treatment plans were re-optimised based on the original plans, and 2) a dose-controlling structure (DCS)-based method, in which the original plans were re-optimised by assigning additional constraints for hot and cold spots. The Original, BDF-based and DCS-based plans were compared with regard to target dose homogeneity, conformity, OAR sparing, planning time and monitor units (MUs). Dosimetric verifications were performed and delivery times were recorded for the BDF-based and DCS-based plans. The BDF-based plans provided significantly superior dose homogeneity and conformity compared with both the DCS-based and Original plans. The BDF-based method further reduced the doses delivered to the OARs by approximately 1-3%. The re-optimisation time was reduced by approximately 28%, but the MUs and delivery time were slightly increased. All verification tests were passed and no significant differences were found. The BDF-based method for the optimisation of IMRT for cervical oesophageal cancer can achieve significantly better dose distributions with better planning efficiency at the expense of slightly more MUs.
Brodin, N P; Björk-Eriksson, T; Birk Christensen, C; Kiil-Berthelsen, A; Aznar, M C; Hollensen, C; Markova, E; Munck af Rosenschöld, P
2015-01-01
Objective: To investigate the impact of including fluorine-18 fludeoxyglucose (18F-FDG) positron emission tomography (PET) scanning in the planning of paediatric radiotherapy (RT). Methods: Target volumes were first delineated without and subsequently re-delineated with access to 18F-FDG PET scan information, on duplicate CT sets. RT plans were generated for three-dimensional conformal photon RT (3DCRT) and intensity-modulated proton therapy (IMPT). The results were evaluated by comparison of target volumes, target dose coverage parameters, normal tissue complication probability (NTCP) and estimated risk of secondary cancer (SC). Results: Considerable deviations between CT- and PET/CT-guided target volumes were seen in 3 out of the 11 patients studied. However, averaging over the whole cohort, CT or PET/CT guidance introduced no significant difference in the shape or size of the target volumes, target dose coverage, irradiated volumes, estimated NTCP or SC risk, neither for IMPT nor 3DCRT. Conclusion: Our results imply that the inclusion of PET/CT scans in the RT planning process could have considerable impact for individual patients. There were no general trends of increasing or decreasing irradiated volumes, suggesting that the long-term morbidity of RT in childhood would on average remain largely unaffected. Advances in knowledge: 18F-FDG PET-based RT planning does not systematically change NTCP or SC risk for paediatric cancer patients compared with CT only. 3 out of 11 patients had a distinct change of target volumes when PET-guided planning was introduced. Dice and mismatch metrics are not sufficient to assess the consequences of target volume differences in the context of RT. PMID:25494657
Varela, Miguel A; Curtis, Helen J; Douglas, Andrew GL; Hammond, Suzan M; O'Loughlin, Aisling J; Sobrido, Maria J; Scholefield, Janine; Wood, Matthew JA
2016-01-01
Allele-specific gene therapy aims to silence expression of mutant alleles through targeting of disease-linked single-nucleotide polymorphisms (SNPs). However, SNP linkage to disease varies between populations, making such molecular therapies applicable only to a subset of patients. Moreover, not all SNPs have the molecular features necessary for potent gene silencing. Here we provide knowledge to allow the maximisation of patient coverage by building a comprehensive understanding of SNPs ranked according to their predicted suitability toward allele-specific silencing in 14 repeat expansion diseases: amyotrophic lateral sclerosis and frontotemporal dementia, dentatorubral-pallidoluysian atrophy, myotonic dystrophy 1, myotonic dystrophy 2, Huntington's disease and several spinocerebellar ataxias. Our systematic analysis of DNA sequence variation shows that most annotated SNPs are not suitable for potent allele-specific silencing across populations because of suboptimal sequence features and low variability (>97% in HD). We suggest maximising patient coverage by selecting SNPs with high heterozygosity across populations, and preferentially targeting SNPs that lead to purine:purine mismatches in wild-type alleles to obtain potent allele-specific silencing. We therefore provide fundamental knowledge on strategies for optimising patient coverage of therapeutics for microsatellite expansion disorders by linking analysis of population genetic variation to the selection of molecular targets. PMID:25990798
Varela, Miguel A; Curtis, Helen J; Douglas, Andrew G L; Hammond, Suzan M; O'Loughlin, Aisling J; Sobrido, Maria J; Scholefield, Janine; Wood, Matthew J A
2016-02-01
Allele-specific gene therapy aims to silence expression of mutant alleles through targeting of disease-linked single-nucleotide polymorphisms (SNPs). However, SNP linkage to disease varies between populations, making such molecular therapies applicable only to a subset of patients. Moreover, not all SNPs have the molecular features necessary for potent gene silencing. Here we provide knowledge to allow the maximisation of patient coverage by building a comprehensive understanding of SNPs ranked according to their predicted suitability toward allele-specific silencing in 14 repeat expansion diseases: amyotrophic lateral sclerosis and frontotemporal dementia, dentatorubral-pallidoluysian atrophy, myotonic dystrophy 1, myotonic dystrophy 2, Huntington's disease and several spinocerebellar ataxias. Our systematic analysis of DNA sequence variation shows that most annotated SNPs are not suitable for potent allele-specific silencing across populations because of suboptimal sequence features and low variability (>97% in HD). We suggest maximising patient coverage by selecting SNPs with high heterozygosity across populations, and preferentially targeting SNPs that lead to purine:purine mismatches in wild-type alleles to obtain potent allele-specific silencing. We therefore provide fundamental knowledge on strategies for optimising patient coverage of therapeutics for microsatellite expansion disorders by linking analysis of population genetic variation to the selection of molecular targets.
Massing, Louis Albert; Aboubakar, Soumah; Page, Anne-Laure; Cohuet, Sandra; Ngandwe, Adalbert; Mukomena Sompwe, Eric; Ramazani, Romain; Allheimen, Marcela; Levaillant, Philippe; Lechevalier, Pauline; Kashimi, Marie; de la Motte, Axelle; Calmejane, Arielle; Bouhenia, Malika; Dabire, Ernest; Bompangue, Didier; Kebela, Benoit; Porten, Klaudia
2018-01-01
Introduction Oral cholera vaccines are primarily recommended by the World Health Organization for cholera control in endemic countries. However, the number of cholera vaccines currently produced is very limited and examples of OCV use in endemic countries, and especially in urban settings, are scarce. A vaccination campaign was organized by Médecins Sans Frontières and the Ministry of Health in a highly endemic area in the Democratic Republic of Congo. This study aims to describe the vaccine coverage achieved with this highly targeted vaccination campaign and the acceptability among the vaccinated communities. Methods and findings We performed a cross-sectional survey using random spatial sampling. The study population included individuals one year old and above, eligible for vaccination, and residing in the areas targeted for vaccination in the city of Kalemie. Data sources were household interviews with verification by vaccination card. In total 2,488 people were included in the survey. Overall, 81.9% (95%CI: 77.9–85.3) of the target population received at least one dose of vaccine. The vaccine coverage with two doses was 67.2% (95%CI: 61.9–72.0) among the target population. The vaccine coverage was higher during the first round (74.0, 95%CI: 69.3–78.3) than during the second round of vaccination (69.1%, 95%CI: 63.9–74.0). Vaccination coverage was lower in male adults. The main reason for non-vaccination was to be absent during the campaign. No severe adverse events were notified during the interviews. Conclusions Cholera vaccination campaigns using highly targeted strategies are feasible in urban settings. High vaccination coverage can be obtained using door to door vaccination. However, alternative strategies should be considered to reach non-vaccinated populations like male adults and also in order to improve the efficiency of the interventions. PMID:29734337
Shi, Chengyu; Guo, Bingqi; Cheng, Chih-Yao; Eng, Tony; Papanikolaou, Nikos
2010-09-21
A low-energy electronic brachytherapy source (EBS), the model S700 Axxent x-ray device developed by Xoft Inc., has been used in high dose rate (HDR) intracavitary accelerated partial breast irradiation (APBI) as an alternative to an Ir-192 source. The prescription dose and delivery schema of the electronic brachytherapy APBI plan are the same as the Ir-192 plan. However, due to its lower mean energy than the Ir-192 source, an EBS plan has dosimetric and biological features different from an Ir-192 source plan. Current brachytherapy treatment planning methods may have large errors in treatment outcome prediction for an EBS plan. Two main factors contribute to the errors: the dosimetric influence of tissue heterogeneities and the enhancement of relative biological effectiveness (RBE) of electronic brachytherapy. This study quantified the effects of these two factors and revisited the plan quality of electronic brachytherapy APBI. The influence of tissue heterogeneities is studied by a Monte Carlo method and heterogeneous 'virtual patient' phantoms created from CT images and structure contours; the effect of RBE enhancement in the treatment outcome was estimated by biologically effective dose (BED) distribution. Ten electronic brachytherapy APBI cases were studied. The results showed that, for electronic brachytherapy cases, tissue heterogeneities and patient boundary effect decreased dose to the target and skin but increased dose to the bones. On average, the target dose coverage PTV V(100) reduced from 95.0% in water phantoms (planned) to only 66.7% in virtual patient phantoms (actual). The actual maximum dose to the ribs is 3.3 times higher than the planned dose; the actual mean dose to the ipsilateral breast and maximum dose to the skin were reduced by 22% and 17%, respectively. Combining the effect of tissue heterogeneities and RBE enhancement, BED coverage of the target was 89.9% in virtual patient phantoms with RBE enhancement (actual BED) as compared to 95.2% in water phantoms without RBE enhancement (planned BED). About 10% increase in the source output is required to raise BED PTV V(100) to 95%. As a conclusion, the composite effect of dose reduction in the target due to heterogeneities and RBE enhancement results in a net effect of 5.3% target BED coverage loss for electronic brachytherapy. Therefore, it is suggested that about 10% increase in the source output may be necessary to achieve sufficient target coverage higher than 95%.
NASA Astrophysics Data System (ADS)
Shi, Chengyu; Guo, Bingqi; Cheng, Chih-Yao; Eng, Tony; Papanikolaou, Nikos
2010-09-01
A low-energy electronic brachytherapy source (EBS), the model S700 Axxent™ x-ray device developed by Xoft Inc., has been used in high dose rate (HDR) intracavitary accelerated partial breast irradiation (APBI) as an alternative to an Ir-192 source. The prescription dose and delivery schema of the electronic brachytherapy APBI plan are the same as the Ir-192 plan. However, due to its lower mean energy than the Ir-192 source, an EBS plan has dosimetric and biological features different from an Ir-192 source plan. Current brachytherapy treatment planning methods may have large errors in treatment outcome prediction for an EBS plan. Two main factors contribute to the errors: the dosimetric influence of tissue heterogeneities and the enhancement of relative biological effectiveness (RBE) of electronic brachytherapy. This study quantified the effects of these two factors and revisited the plan quality of electronic brachytherapy APBI. The influence of tissue heterogeneities is studied by a Monte Carlo method and heterogeneous 'virtual patient' phantoms created from CT images and structure contours; the effect of RBE enhancement in the treatment outcome was estimated by biologically effective dose (BED) distribution. Ten electronic brachytherapy APBI cases were studied. The results showed that, for electronic brachytherapy cases, tissue heterogeneities and patient boundary effect decreased dose to the target and skin but increased dose to the bones. On average, the target dose coverage PTV V100 reduced from 95.0% in water phantoms (planned) to only 66.7% in virtual patient phantoms (actual). The actual maximum dose to the ribs is 3.3 times higher than the planned dose; the actual mean dose to the ipsilateral breast and maximum dose to the skin were reduced by 22% and 17%, respectively. Combining the effect of tissue heterogeneities and RBE enhancement, BED coverage of the target was 89.9% in virtual patient phantoms with RBE enhancement (actual BED) as compared to 95.2% in water phantoms without RBE enhancement (planned BED). About 10% increase in the source output is required to raise BED PTV V100 to 95%. As a conclusion, the composite effect of dose reduction in the target due to heterogeneities and RBE enhancement results in a net effect of 5.3% target BED coverage loss for electronic brachytherapy. Therefore, it is suggested that about 10% increase in the source output may be necessary to achieve sufficient target coverage higher than 95%.
Fuller, James A; Villamor, Eduardo; Cevallos, William; Trostle, James; Eisenberg, Joseph NS
2016-01-01
Abstract Background: Infectious disease interventions, such as vaccines and bed nets, have the potential to provide herd protection to non-recipients. Similarly, improved sanitation in one household may provide community-wide benefits if it reduces contamination in the shared environment. Sanitation at the household level is an important predictor of child growth, but less is known about the effect of sanitation coverage in the community. Methods: From 2008 to 2013, we took repeated anthropometric measurements on 1314 children under 5 years of age in 24 rural Ecuadorian villages. Using mixed effects regression, we estimated the association between sanitation coverage in surrounding households and child growth. Results: Sanitation coverage in the surrounding households was strongly associated with child height, as those with 100% coverage in their surroundings had a 67% lower prevalence of stunting [prevalence ratio (PR) 0.32, 95% CI 0.15-0.69] compared with those with 0% coverage. Children from households with improved sanitation had a lower prevalence of stunting (PR 0.86, 95% CI 0.64-1.15). When analysing height as a continuous outcome, the protective effect of sanitation coverage is manifested primarily among girls during the second year of life, the time at which growth faltering is most likely to occur. Conclusions: Our study highlights that a household’s sanitation practices can provide herd protection to the overall community. Studies which fail to account for the positive externalities that sanitation provides will underestimate the overall protective effect. Future studies could seek to identify a threshold of sanitation coverage, similar to a herd immunity threshold, to provide coverage and compliance targets. PMID:26936912
Adetokunboh, Olatunji O; Uthman, Olalekan A; Wiysonge, Charles S
2018-05-02
We investigated the relationship between maternal HIV status and uptake of the full series of three doses of diphtheria-tetanus-pertussis containing vaccines (DTP3) in sub-Saharan African children. We used data obtained from demographic and health surveys conducted in sub-Saharan Africa. We conducted meta-analysis and calculated pooled odds ratios (OR) for the association between maternal HIV status and DTP3 vaccination status for each country. A total of 4,187 out of 5,537 children of women living with HIV received DTP3 (75.6%), compared to 71,290 of 113,513 (62.8%) children of HIV negative women. National DTP3 coverage among children of HIV-positive women varied between 24% and 96% while among children of HIV negative women it was between 26% and 92%. Overall pooled result showed no significant difference in DTP3 coverage between the two groups (OR = 1.05; 95% confidence interval 0.91 - 1.22), with statistically significant heterogeneity (Chi 2 = 91.63, P = 0.000, I 2 = 71.6%). There was no significant association between DTP3 coverage and maternal HIV status in sub-Saharan Africa. However, DTP3 coverage for both HIV-exposed and non-exposed children were below the required target. Meta-regression revealed no significant association between DTP3 coverage and country characteristics (e.g. HIV prevalence among women, antiretroviral therapy coverage, gross domestic product per capita, human development index, adult literacy rate and sub-region). Improved prevention of mother-to-child transmission services might have contributed to some extent to the higher DTP3 vaccination coverage among the HIV-exposed children. There is also need to address barriers impeding uptake of vaccination among HIV-exposed and non-exposed children.
Verges, Ramona; Giraldo, Alexandra; Seoane, Alejandro; Toral, Elisabet; Ruiz, M Carmen; Pons, Ariadna; Giralt, Jordi
2018-01-01
To find out whether the internal target volume (ITV) vaginal procedure ensures dosimetric coverage during intensity-modulated radiation therapy (IMRT) of post-operative gynaecological tumours without instructions on rectal filling. The ITV vaginal procedure does not necessarily include all movements of the bladder, and does not include changes in the rectal volume. We should know if the vaginal ITV is a useful tool in maintaining CTV coverage during treatment. A retrospective analysis of 24 patients treated between July 2012 and July 2014 with adjuvant IMRT for gynaecological cancer. All patients underwent empty and full bladder CT on simulation (CT-planning) and three weeks later (CT-control). ITV displacement was measured and the 3D vector was calculated. ITV coverage was then evaluated by comparing the volume covered by the prescription isodose on both CT's. Patients were asked to have full bladder but they did not follow recommendations for the rectum. The mean 3D vector was 0.64 ± 0.32 cm (0.09-1.30). The mean ITV coverage loss was 5.8 ± 5.7% (0-20.2). We found a significant positive correlation between the 3D vector and the loss of coverage (Pearson correlation, r = 0.493, 95% CI: 0.111-0.748, p = 0.0144). We did not find any significant correlation between the bladder and rectal parameters with the 3D vector and loss of dosimetric coverage. We found a trend between the maximum rectal diameter in CT-planning and 3D vector ( r = 0.400, 95% CI: -0.004 to 0.692, p = 0.0529). ITV vaginal procedure contributed to ensuring a good dose coverage without instructions on rectal filling.
Women's magazine coverage of heart disease risk factors: Good Housekeeping magazine, 1997 to 2007.
Edy, Carolyn M
2010-03-01
Women, who often turn to magazines for health information, continue to underestimate their risk for heart disease, though it remains the leading cause of death among women in the United States. This textual analysis considered the portrayal of women's risk factors for heart disease as problem and remedy frames within articles published by the highest circulation women's magazine in the U.S., Good Housekeeping, from 1997 to 2007. These findings were then compared with corresponding information endorsed by the American Heart Association. Far from underestimating a woman's risk for heart disease, GH articles seemed to target women at low risk for heart disease, while emphasizing risk factors unique to women. The magazine coverage was largely consistent with American Heart Association information, yet offered a broader range of treatment and prevention strategies that were sometimes contradictory or vague. One significant risk factor, race, was not mentioned in the magazine articles. This review calls for future research to determine the pervasiveness and possible effects of such coverage.
A novel dose-based positioning method for CT image-guided proton therapy
Cheung, Joey P.; Park, Peter C.; Court, Laurence E.; Ronald Zhu, X.; Kudchadker, Rajat J.; Frank, Steven J.; Dong, Lei
2013-01-01
Purpose: Proton dose distributions can potentially be altered by anatomical changes in the beam path despite perfect target alignment using traditional image guidance methods. In this simulation study, the authors explored the use of dosimetric factors instead of only anatomy to set up patients for proton therapy using in-room volumetric computed tomographic (CT) images. Methods: To simulate patient anatomy in a free-breathing treatment condition, weekly time-averaged four-dimensional CT data near the end of treatment for 15 lung cancer patients were used in this study for a dose-based isocenter shift method to correct dosimetric deviations without replanning. The isocenter shift was obtained using the traditional anatomy-based image guidance method as the starting position. Subsequent isocenter shifts were established based on dosimetric criteria using a fast dose approximation method. For each isocenter shift, doses were calculated every 2 mm up to ±8 mm in each direction. The optimal dose alignment was obtained by imposing a target coverage constraint that at least 99% of the target would receive at least 95% of the prescribed dose and by minimizing the mean dose to the ipsilateral lung. Results: The authors found that 7 of 15 plans did not meet the target coverage constraint when using only the anatomy-based alignment. After the authors applied dose-based alignment, all met the target coverage constraint. For all but one case in which the target dose was met using both anatomy-based and dose-based alignment, the latter method was able to improve normal tissue sparing. Conclusions: The authors demonstrated that a dose-based adjustment to the isocenter can improve target coverage and/or reduce dose to nearby normal tissue. PMID:23635262
Dental Use and Expenditures for Older Uninsured Americans: The Simulated Impact of Expanded Coverage
Manski, Richard J; Moeller, John F; Chen, Haiyan; Schimmel, Jody; Pepper, John V; St Clair, Patricia A
2015-01-01
Objective To determine if providing dental insurance to older Americans would close the current gaps in dental use and expenditure between insured and uninsured older Americans. Data Sources/Study Setting We used data from the 2008 Health and Retirement Survey (HRS) supplemented by data from the 2006 Medical Expenditure Panel Survey (MEPS). Study Design We compared the simulated dental use and expenditures rates of newly insured persons against the corresponding rates for those previously insured. Data Collection/Extraction Methods The HRS is a nationally representative survey administered by the Institute for Social Research (ISR). The MEPS is a nationally representative household survey sponsored by the Agency for Healthcare Research and Quality (AHRQ). Principal Findings We found that expanding dental coverage to older uninsured Americans would close previous gaps in dental use and expense between uninsured and insured noninstitutionalized Americans 55 years and older. Conclusions Providing dental coverage to previously uninsured older adults would produce estimated monthly costs net of markups for administrative costs that comport closely to current market rates. Estimates also suggest that the total cost of providing dental coverage targeted specifically to nonusers of dental care may be less than similar costs for prior users. PMID:25040355
Machalek, Dorothy A; Garland, Suzanne M; Brotherton, Julia M L; Bateson, Deborah; McNamee, Kathleen; Stewart, Mary; Rachel Skinner, S; Liu, Bette; Cornall, Alyssa M; Kaldor, John M; Tabrizi, Sepehr N
2018-04-23
A quadrivalent human papillomavirus vaccination program targeting females aged 12-13 years commenced in Australia in 2007, with catch-up vaccination of 14-26 year olds through 2009. We evaluated the program's impact on HPV prevalence among women aged 18-35 in 2015. HPV prevalence among women aged 18-24 and 25-35 was compared with prevalence in these age groups in 2005-2007. For women aged 18-24, we also compared prevalence with that in a postvaccine study conducted in 2010-2012. For the 2015 sample, Vaccination Register-confirmed 3-dose coverage was 53.3% (65.0% and 40.3% aged 18-24 and 25-35, respectively). Prevalence of vaccine HPV types decreased from 22.7% (2005-2007) and 7.3% (2010-2012), to 1.5% (2015) (P trend < .001) among women aged 18-24, and from 11.8% (2005-2007) to 1.1% (2015) (P = .001) among those aged 25-35. This study, reporting the longest surveillance follow-up to date, shows prevalence of vaccine-targeted HPV types has continued to decline among young women. A substantial fall also occurred in women aged 25-35, despite lower coverage. Strong herd protection and effectiveness of less than 3 vaccine doses likely contributed to these reductions.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Vikraman, S; Rajesh, Thiyagarajan; Karrthick, Kp
2015-06-15
Purpose: The purpose of this study was to evaluate multiple brain metastases stereotactic treatment planning of Cyberknife versus linac using dose volume based indices. Methods: Fifteen multiple brain metastases patients were taken for this study from Cyberknife Multiplan TPSv4.6.0. All these patients underwent stereotactic treatment in Cyberknife. For each patient VMAT stereotactic treatment plan was generated in MONACO TPSv5.0 using Elekta beam modulator MLC and matched the delivered plan. A median dose of 8.5Gy(range 7–12Gy) per fraction was prescribed. Tumor volume was in the range of 0.06–4.33cc. Treatment plan quality was critically evaluated by comparing DVH indices such as D98,more » D95, CI, and HI for target volumes. Maximum point doses and volume doses were evaluated for critical organs. Results: For each case, target coverage of D98 was achieved with 100% prescription dose with SD of 0.29% and 0.41% in Linac and Cyberknife respectively. The average conformity index(CI) of 1.26±0.0796 SD for Cyberknife and 1.92±0.60SD for linac were observed. Better homogeneity Index (HI) of 1.17±0.09SD was observed in linac as compared to Cyberknife HI of 1.24±0.05SD.All the critical organ doses were well within tolerance limit in both linac and Cyberknife plans. There is no significant difference of maximum point doses for brainstem and optic chiasm. Treatment time and number of monitor units are more in Cyberknife compared to linac. The average volume receiving 12Gy in whole brain was 6% and 12% for Cyberknife and linac respectively. 1000cc of whole brain received 60% lesser dose in Linac compared to Cyberknife in all cases. Conclusion: The study shows that dosimetrically comparable plans are achievable Cyberknife and Linac. However, a better conformity, target coverage, lesser OAR dose is achieved with Cyberknife due to greater degrees of freedom with robotic gantry and smaller collimator for multiple targets.« less
Heart failure disease management programs: a cost-effectiveness analysis.
Chan, David C; Heidenreich, Paul A; Weinstein, Milton C; Fonarow, Gregg C
2008-02-01
Heart failure (HF) disease management programs have shown impressive reductions in hospitalizations and mortality, but in studies limited to short time frames and high-risk patient populations. Current guidelines thus only recommend disease management targeted to high-risk patients with HF. This study applied a new technique to infer the degree to which clinical trials have targeted patients by risk based on observed rates of hospitalization and death. A Markov model was used to assess the incremental life expectancy and cost of providing disease management for high-risk to low-risk patients. Sensitivity analyses of various long-term scenarios and of reduced effectiveness in low-risk patients were also considered. The incremental cost-effectiveness ratio of extending coverage to all patients was $9700 per life-year gained in the base case. In aggregate, universal coverage almost quadrupled life-years saved as compared to coverage of only the highest quintile of risk. A worst case analysis with simultaneous conservative assumptions yielded an incremental cost-effectiveness ratio of $110,000 per life-year gained. In a probabilistic sensitivity analysis, 99.74% of possible incremental cost-effectiveness ratios were <$50,000 per life-year gained. Heart failure disease management programs are likely cost-effective in the long-term along the whole spectrum of patient risk. Health gains could be extended by enrolling a broader group of patients with HF in disease management.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Yim, Jackie; Suttie, Clare; Bromley, Regina
We report on a retrospective dosimetric study, comparing 3D conformal radiotherapy (3DCRT) and hybrid intensity modulated radiotherapy (hIMRT). We evaluated plans based on their planning target volume coverage, dose homogeneity, dose to organs at risk (OARs) and exposure of normal tissue to radiation. The Homogeneity Index (HI) was used to assess the dose homogeneity in the target region, and we describe a new index, the normal tissue index (NTI), to assess the dose in the normal tissue inside the tangent treatment portal. Plans were generated for 25 early-stage breast cancer patients, using a hIMRT technique. These were compared with themore » 3DCRT plans of the treatment previously received by the patients. Plan quality was evaluated using the HI, NTI and dose to OARs. The hIMRT technique was significantly more homogenous than the 3DCRT technique, while maintaining target coverage. The hIMRT technique was also superior at minimising the amount of tissue receiving D{sub 105%} and above (P < 0.0001). The ipsilateral lung and contralateral breast maximum were significantly lower in the hIMRT plans (P < 0.05 and P < 0.005), but the 3DCRT technique achieved a lower mean heart dose in left-sided breast cancer patients (P < 0.05). Hybrid intensity modulated radiotherapy plans achieved improved dose homogeneity compared to the 3DCRT plans and superior outcome with regard to dose to normal tissues. We propose that the addition of both HI and NTI in evaluating the quality of intensity modulated radiotherapy (IMRT) breast plans provides clinically relevant comparators which more accurately reflect the new paradigm of treatment goals and outcomes in the era of breast IMRT.« less
Hanifi, S.M.A.; Roy, Nikhil; Streatfield, P. Kim
2007-01-01
This paper compared the performance of the lot quality assurance sampling (LQAS) method in identifying inadequately-performing health work-areas with that of using health and demographic surveillance system (HDSS) data and examined the feasibility of applying the method by field-level programme supervisors. The study was carried out in Matlab, the field site of ICDDR,B, where a HDSS has been in place for over 30 years. The LQAS method was applied in 57 work-areas of community health workers in ICDDR,B-served areas in Matlab during July-September 2002. The performance of the LQAS method in identifying work-areas with adequate and inadequate coverage of various health services was compared with those of the HDSS. The health service-coverage indicators included coverage of DPT, measles, BCG vaccination, and contraceptive use. It was observed that the difference in the proportion of work-areas identified to be inadequately performing using the LQAS method with less than 30 respondents, and the HDSS was not statistically significant. The consistency between the LQAS method and the HDSS in identifying work-areas was greater for adequately-performing areas than inadequately-performing areas. It was also observed that the field managers could be trained to apply the LQAS method in monitoring their performance in reaching the target population. PMID:17615902
Bhuiya, Abbas; Hanifi, S M A; Roy, Nikhil; Streatfield, P Kim
2007-03-01
This paper compared the performance of the lot quality assurance sampling (LQAS) method in identifying inadequately-performing health work-areas with that of using health and demographic surveillance system (HDSS) data and examined the feasibility of applying the method by field-level programme supervisors. The study was carried out in Matlab, the field site of ICDDR,B, where a HDSS has been in place for over 30 years. The LQAS method was applied in 57 work-areas of community health workers in ICDDR,B-served areas in Matlab during July-September 2002. The performance of the LQAS method in identifying work-areas with adequate and inadequate coverage of various health services was compared with those of the HDSS. The health service-coverage indicators included coverage of DPT, measles, BCG vaccination, and contraceptive use. It was observed that the difference in the proportion of work-areas identified to be inadequately performing using the LQAS method with less than 30 respondents, and the HDSS was not statistically significant. The consistency between the LQAS method and the HDSS in identifying work-areas was greater for adequately-performing areas than inadequately-performing areas. It was also observed that the field managers could be trained to apply the LQAS method in monitoring their performance in reaching the target population.
Assessing pooled BAC and whole genome shotgun strategies for assembly of complex genomes
2011-01-01
Background We investigate if pooling BAC clones and sequencing the pools can provide for more accurate assembly of genome sequences than the "whole genome shotgun" (WGS) approach. Furthermore, we quantify this accuracy increase. We compare the pooled BAC and WGS approaches using in silico simulations. Standard measures of assembly quality focus on assembly size and fragmentation, which are desirable for large whole genome assemblies. We propose additional measures enabling easy and visual comparison of assembly quality, such as rearrangements and redundant sequence content, relative to the known target sequence. Results The best assembly quality scores were obtained using 454 coverage of 15× linear and 5× paired (3kb insert size) reads (15L-5P) on Arabidopsis. This regime gave similarly good results on four additional plant genomes of very different GC and repeat contents. BAC pooling improved assembly scores over WGS assembly, coverage and redundancy scores improving the most. Conclusions BAC pooling works better than WGS, however, both require a physical map to order the scaffolds. Pool sizes up to 12Mbp work well, suggesting this pooling density to be effective in medium-scale re-sequencing applications such as targeted sequencing of QTL intervals for candidate gene discovery. Assuming the current Roche/454 Titanium sequencing limitations, a 12 Mbp region could be re-sequenced with a full plate of linear reads and a half plate of paired-end reads, yielding 15L-5P coverage after read pre-processing. Our simulation suggests that massively over-sequencing may not improve accuracy. Our scoring measures can be used generally to evaluate and compare results of simulated genome assemblies. PMID:21496274
Buckee, Caroline O.
2018-01-01
Background Oral cholera vaccination is an approach to preventing outbreaks in at-risk settings and controlling cholera in endemic settings. However, vaccine-derived herd immunity may be short-lived due to interactions between human mobility and imperfect or waning vaccine efficacy. As the supply and utilization of oral cholera vaccines grows, critical questions related to herd immunity are emerging, including: who should be targeted; when should revaccination be performed; and why have cholera outbreaks occurred in recently vaccinated populations? Methods and findings We use mathematical models to simulate routine and mass oral cholera vaccination in populations with varying degrees of migration, transmission intensity, and vaccine coverage. We show that migration and waning vaccine efficacy strongly influence the duration of herd immunity while birth and death rates have relatively minimal impacts. As compared to either periodic mass vaccination or routine vaccination alone, a community could be protected longer by a blended “Mass and Maintain” strategy. We show that vaccination may be best targeted at populations with intermediate degrees of mobility as compared to communities with very high or very low population turnover. Using a case study of an internally displaced person camp in South Sudan which underwent high-coverage mass vaccination in 2014 and 2015, we show that waning vaccine direct effects and high population turnover rendered the camp over 80% susceptible at the time of the cholera outbreak beginning in October 2016. Conclusions Oral cholera vaccines can be powerful tools for quickly protecting a population for a period of time that depends critically on vaccine coverage, vaccine efficacy over time, and the rate of population turnover through human mobility. Due to waning herd immunity, epidemics in vaccinated communities are possible but become less likely through complementary interventions or data-driven revaccination strategies. PMID:29489815
Massat, Nathalie J; Douglas, Elaine; Waller, Jo; Wardle, Jane; Duffy, Stephen W
2015-07-24
Reducing cancer screening inequalities in England is a major focus of the 2011 Department of Health cancer outcome strategy. Screening coverage requires regular monitoring in order to implement targeted interventions where coverage is low. This study aimed to characterise districts with atypical coverage levels for cervical or breast screening. Observational study of district-level coverage in the English Cervical and Breast screening programmes in 2012. England, UK. All English women invited to participate in the cervical (age group 25-49 and 50-64) and breast (age group 50-64) screening programmes. Risk adjustment models for coverage were developed based on district-level characteristics. Funnel plots of adjusted coverage were constructed, and atypical districts examined by correlation analysis. Variability in coverage was primarily explained by population factors, whereas general practice characteristics had little independent effect. Deprivation and ethnicity other than white, Asian, black or mixed were independently associated with poorer coverage in both screening programmes, with ethnicity having the strongest effect; by comparison, the influence of Asian, black or mixed ethnic minority was limited. Deprivation, ethnicity and urbanisation largely accounted for the lower cervical screening coverage in London. However, for breast screening, being located in London remained a strong negative predictor. A subset of districts was identified as having atypical coverage across programmes. Correlates of deprivation in districts with relatively low adjusted coverage were substantially different from overall correlates of deprivation. These results inform the continuing drive to reduce avoidable cancer deaths in England, and encourage implementation of targeted interventions in communities residing in districts identified as having atypically low coverage. Sequential implementation to monitor the impact of local interventions would help accrue evidence on 'what works'. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Water, Tara A. van de, E-mail: t.a.van.de.water@rt.umcg.nl; Lomax, Antony J.; Bijl, Hendrik P.
2012-02-01
Purpose: To investigate whether intensity-modulated proton therapy with a reduced spot size (rsIMPT) could further reduce the parotid and submandibular gland dose compared with previously calculated IMPT plans with a larger spot size. In addition, it was investigated whether the obtained dose reductions would theoretically translate into a reduction of normal tissue complication probabilities (NTCPs). Methods: Ten patients with N0 oropharyngeal cancer were included in a comparative treatment planning study. Both IMPT plans delivered simultaneously 70 Gy to the boost planning target volume (PTV) and 54 Gy to the elective nodal PTV. IMPT and rsIMPT used identical three-field beam arrangements.more » In the IMPT plans, the parotid and submandibular salivary glands were spared as much as possible. rsIMPT plans used identical dose-volume objectives for the parotid glands as those used by the IMPT plans, whereas the objectives for the submandibular glands were tightened further. NTCPs were calculated for salivary dysfunction and xerostomia. Results: Target coverage was similar for both IMPT techniques, whereas rsIMPT clearly improved target conformity. The mean doses in the parotid glands and submandibular glands were significantly lower for three-field rsIMPT (14.7 Gy and 46.9 Gy, respectively) than for three-field IMPT (16.8 Gy and 54.6 Gy, respectively). Hence, rsIMPT significantly reduced the NTCP of patient-rated xerostomia and parotid and contralateral submandibular salivary flow dysfunction (27%, 17%, and 43% respectively) compared with IMPT (39%, 20%, and 79%, respectively). In addition, mean dose values in the sublingual glands, the soft palate and oral cavity were also decreased. Obtained dose and NTCP reductions varied per patient. Conclusions: rsIMPT improved sparing of the salivary glands and reduced NTCP for xerostomia and parotid and submandibular salivary dysfunction, while maintaining similar target coverage results. It is expected that rsIMPT improves quality of life during and after radiotherapy treatment.« less
Jorgensen, Pernille; Mereckiene, Jolita; Cotter, Suzanne; Johansen, Kari; Tsolova, Svetla; Brown, Caroline
2018-01-25
Influenza vaccination is recommended especially for persons at risk of complications. In 2003, the World Health Assembly urged Member States (MS) to increase vaccination coverage to 75% among older persons by 2010. To assess progress towards the 2010 vaccination goal and describe seasonal influenza vaccination recommendations in the World Health Organization (WHO) European Region. Data on seasonal influenza vaccine recommendations, dose distribution, and target group coverage were obtained from two sources: European Union and European Economic Area MS data were extracted from influenza vaccination surveys covering seven seasons (2008/2009-2014/2015) published by the Vaccine European New Integrated Collaboration Effort and European Centre for Disease Prevention and Control. For the remaining WHO European MS, a separate survey on policies and uptake for all seasons (2008/2009-2014/2015) was distributed to national immunization programmes in 2015. Data was available from 49 of 53 MS. All but two had a national influenza vaccination policy. High-income countries distributed considerably higher number of vaccines per capita (median; 139.2 per 1000 population) compared to lower-middle-income countries (median; 6.1 per 1000 population). Most countries recommended vaccination for older persons, individuals with chronic disease, healthcare workers, and pregnant women. Children were included in < 50% of national policies. Only one country reached 75% coverage in older persons (2014/2015), while a number of countries reported declining vaccination uptake. Coverage of target groups was overall low, but with large variations between countries. Vaccination coverage was not monitored for several groups. Despite policy recommendations, influenza vaccination uptake remains suboptimal. Low levels of vaccination is not only a missed opportunity for preventing influenza in vulnerable groups, but could negatively affect pandemic preparedness. Improved understanding of barriers to influenza vaccination is needed to increase uptake and reverse negative trends. Furthermore, implementation of vaccination coverage monitoring is critical for assessing performance and impact of the programmes. Copyright © 2017. Published by Elsevier Ltd.
Measuring individual-level needle and syringe coverage among people who inject drugs in Myanmar.
O'Keefe, Daniel; Aung, Soe Moe; Pasricha, Naanki; Wun, Thu; Linn, Soe Khaing; Lin, Nay; Aitken, Campbell; Hughes, Chad; Dietze, Paul
2018-05-10
Myanmar has prioritised people who inject drugs (PWID) as a key population for HIV mitigation efforts, with targets for needle and syringe distribution set at a population level. However, individual-level coverage, defined as the percentage of an individual's injecting episodes covered by a sterile syringe, is a more sensitive measure of intervention coverage. We sought to examine individual-level coverage in a sample of PWID in Myanmar. We recruited 512 PWID through urban drop-in-centres in Yangon, Mandalay and Pyin Oo Lwin. Participants were administered a quantitative questionnaire covering five domains: demographics, drug use, treatment and coverage, and injecting risk behaviour. We calculated past fortnight individual-level syringe coverage, estimating levels of sufficient (≥100% of injecting episodes covered by a sterile syringe) and insufficient (<100%) coverage, and examined associations between key variables and insufficient coverage via logistic regression. Our sample was predominately male (97%), employed (76%), and living in stable accommodation (96%), with a median age of 27. All participants reported heroin as the drug most frequently injected, and injected a median of 27 times in the past two weeks. Nineteen per cent of participants had insufficient coverage in the two weeks before interview. Insufficient coverage was positively associated with syringe re-use (AOR: 5.19, 95% CIs: 2.57, 10.48) and acquiring sterile syringes from a location other than a formal drop-in-centre (AOR: 2.04, 95% CIs: 1.08, 3.82). Participants recruited in Mandalay (AOR: 0.30, 95% CIs: 0.11, 0.80) and Pyin Oo Lwin (AOR: 0.39, 95% CIs: 0.18, 0.87) had lower odds of insufficient coverage than those recruited in Yangon. Our study shows coverage in selected areas of Myanmar was comparable with studies in other countries. Our results inform the delivery of harm reduction services for PWID, specifically by encouraging the use of formal drop-in-centres, over other sources of syringe distribution, such as pharmacies. Copyright © 2018 Elsevier B.V. All rights reserved.
Shuaibu, Faisal M; Birukila, Gerida; Usman, Samuel; Mohammed, Ado; Galway, Michael; Corkum, Melissa; Damisa, Eunice; Mkanda, Pascal; Mahoney, Frank; Wa Nganda, Gatei; Vertefeuille, John; Chavez, Anna; Meleh, Sule; Banda, Richard; Some, Almai; Mshelia, Hyelni; Umar, Al-Umra; Enemaku, Ogu; Etsano, Andrew
2016-02-01
The use of Inactivated Polio Vaccine (IPV) in routine immunization to replace Oral Polio Vaccine (OPV) is crucial in eradicating polio. In June 2014, Nigeria launched an IPV campaign in the conflict-affected states of Borno and Yobe, the largest ever implemented in Africa. We present the initiatives and lessons learned. The 8-day event involved two parallel campaigns. OPV target age was 0-59 months, while IPV targeted all children aged 14 weeks to 59 months. The Borno state primary health care agency set up temporary health camps for the exercise and treated minor ailments for all. The target population for the OPV campaign was 685,674 children in Borno and 113,774 in Yobe. The IPV target population for Borno was 608,964 and for Yobe 111,570. OPV coverage was 105.1 per cent for Borno and 103.3 per cent for Yobe. IPV coverage was 102.9 per cent for Borno and 99.1 per cent for Yobe. (Where we describe coverage as greater than 100 per cent, this reflects original underestimates of the target populations.) A successful campaign and IPV immunization is viable in conflict areas.
Kralik, John C.; Xi, Liwen; Solberg, Timothy D.; Simone, Charles B.
2015-01-01
Target coverage and organ‐at‐risk sparing were compared for 22 pediatric patients with primary brain tumors treated using two distinct nozzles in pencil beam scanning (PBS) proton therapy. Consecutive patients treated at our institution using a PBS‐dedicated nozzle (DN) were replanned using a universal nozzle (UN) beam model and the original DN plan objectives. Various cranial sites were treated among the patients to prescription doses ranging from 45 to 54 Gy. Organs at risk (OARs) evaluated were patient‐dependent; 15 unique OARs were analyzed, all of which were assessed in at least 10 patients. Clinical target volume (CTV) coverage and organ sparing were compared for the two nozzles using dose‐volume histogram data. Statistical analysis using a confidence‐interval approach demonstrates that CTV coverage is equivalent for UN and DN plans within ±5% equivalence bounds. In contrast, average mean and maximum doses are significantly higher for nearly all 15 OARs in the UN plans. The average median increase over all OARs and patients is approximately 1.7 Gy, with an increase in the 25%–75% of 1.0–2.3 Gy; the median increase to the pituitary gland, temporal lobes, eyes and cochleas are 1.8, 1.7, 0.7, and 2.7 Gy, respectively. The CTV dose distributions fall off slower for UN than for the DN plans; hence, normal tissue structures in close proximity to CTVs receive higher doses in UN plans than in DN plans. The higher OAR doses in the UN plans are likely due to the larger spot profile in plans created with UN beams. In light of the high rates of toxicities in pediatric patients receiving cranial irradiation and in light of selected brain tumor types having high cure rates, this study suggests the smaller DN beam profile is preferable for the advantage of reducing dose to OARs. PACS number: 87.55.D‐ PMID:26699553
Neelsen, Sven; O'Donnell, Owen
2017-12-01
Like other countries seeking a progressive path to universalism, Peru has attempted to reduce inequalities in access to health care by granting the poor entitlement to tax-financed basic care without charge. We identify the impact of this policy by comparing the target population's change in health care utilization with that of poor adults already covered through employment-based insurance. There are positive effects on receipt of ambulatory care and medication that are largest among the elderly and the poorest. The probability of getting formal health care when sick is increased by almost two fifths, but the likelihood of being unable to afford treatment is reduced by more than a quarter. Consistent with the shallow coverage offered, there is no impact on use of inpatient care. Neither is there any effect on average out-of-pocket health care expenditure, but medical spending is reduced by up to 25% in the top quarter of the distribution. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.
Alsallaq, Ramzi A; Buttolph, Jasmine; Cleland, Charles M; Hallett, Timothy; Inwani, Irene; Agot, Kawango; Kurth, Ann E
2017-01-01
We compared the impact and costs of HIV prevention strategies focusing on youth (15-24 year-old persons) versus on adults (15+ year-old persons), in a high-HIV burden context of a large generalized epidemic. Compartmental age-structured mathematical model of HIV transmission in Nyanza, Kenya. The interventions focused on youth were high coverage HIV testing (80% of youth), treatment at diagnosis (TasP, i.e., immediate start of antiretroviral therapy [ART]) and 10% increased condom usage for HIV-positive diagnosed youth, male circumcision for HIV-negative young men, pre-exposure prophylaxis (PrEP) for high-risk HIV-negative females (ages 20-24 years), and cash transfer for in-school HIV-negative girls (ages 15-19 years). Permutations of these were compared to adult-focused HIV testing coverage with condoms and TasP. The youth-focused strategy with ART treatment at diagnosis and condom use without adding interventions for HIV-negative youth performed better than the adult-focused strategy with adult testing reaching 50-60% coverage and TasP/condoms. Over the long term, the youth-focused strategy approached the performance of 70% adult testing and TasP/condoms. When high coverage male circumcision also is added to the youth-focused strategy, the combined intervention outperformed the adult-focused strategy with 70% testing, for at least 35 years by averting 94,000 more infections, averting 5.0 million more disability-adjusted life years (DALYs), and saving US$46.0 million over this period. The addition of prevention interventions beyond circumcision to the youth-focused strategy would be more beneficial if HIV care costs are high, or when program delivery costs are relatively high for programs encompassing HIV testing coverage exceeding 70%, TasP and condoms to HIV-infected adults compared to combination prevention programs among youth. For at least the next three decades, focusing in high burden settings on high coverage HIV testing, ART treatment upon diagnosis, condoms and male circumcision among youth may outperform adult-focused ART treatment upon diagnosis programs, unless the adult testing coverage in these programs reaches very high levels (>70% of all adults reached) at similar program costs. Our results indicate the potential importance of age-targeting for HIV prevention in the current era of 'test and start, ending AIDS' goals to ameliorate the HIV epidemic globally.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Salem, Ahmed, E-mail: ahmed.salem@doctors.org.uk; Mohamad, Issa; Dayyat, Abdulmajeed
2015-10-01
Radiation pneumonitis is a well-documented side effect of radiation therapy for breast cancer. The purpose of this study was to compare combined photon-electron, photon-only, and electron-only plans in the radiation treatment of the supraclavicular lymph nodes. In total, 13 patients requiring chest wall and supraclavicular nodal irradiation were planned retrospectively using combined photon-electron, photon-only, and electron-only supraclavicular beams. A dose of 50 Gy over 25 fractions was prescribed. Chest wall irradiation parameters were fixed for all plans. The goal of this planning effort was to cover 95% of the supraclavicular clinical target volume (CTV) with 95% of the prescribed dosemore » and to minimize the volume receiving ≥ 105% of the dose. Comparative end points were supraclavicular CTV coverage (volume covered by the 95% isodose line), hotspot volume, maximum radiation dose, contralateral breast dose, mean total lung dose, total lung volume percentage receiving at least 20 Gy (V{sub 20} {sub Gy}), heart volume percentage receiving at least 25 Gy (V{sub 25} {sub Gy}). Electron and photon energies ranged from 8 to 18 MeV and 4 to 6 MV, respectively. The ratio of photon-to-electron fractions in combined beams ranged from 5:20 to 15:10. Supraclavicular nodal coverage was highest in photon-only (mean = 96.2 ± 3.5%) followed closely by combined photon-electron (mean = 94.2 ± 2.5%) and lowest in electron-only plans (mean = 81.7 ± 14.8%, p < 0.001). The volume of tissue receiving ≥ 105% of the prescription dose was higher in the electron-only (mean = 69.7 ± 56.1 cm{sup 3}) as opposed to combined photon-electron (mean = 50.8 ± 40.9 cm{sup 3}) and photon-only beams (mean = 32.2 ± 28.1 cm{sup 3}, p = 0.114). Heart V{sub 25} {sub Gy} was not statistically different among the plans (p = 0.999). Total lung V{sub 20} {sub Gy} was lowest in electron-only (mean = 10.9 ± 2.3%) followed by combined photon-electron (mean = 13.8 ± 2.3%) and highest in photon-only plans (mean = 16.2 ± 3%, p < 0.001). As expected, photon-only plans demonstrated the highest target coverage and total lung V{sub 20} {sub Gy}. The superiority of electron-only beams, in terms of decreasing lung dose, is set back by the dosimetric hotspots associated with such plans. Combined photon-electron treatment is a feasible technique for supraclavicular nodal irradiation and results in adequate target coverage, acceptable dosimetric hotspot volume, and slightly reduced lung dose.« less
Knopp, Stefanie; Person, Bobbie; Ame, Shaali M; Ali, Said M; Muhsin, Juma; Juma, Saleh; Khamis, Iddi S; Rabone, Muriel; Blair, Lynsey; Fenwick, Alan; Mohammed, Khalfan A; Rollinson, David
2016-01-04
Biannual mass drug administration (MDA) with praziquantel and additional interventions to eliminate urogenital schistosomiasis has been implemented on the Zanzibar islands, United Republic of Tanzania, since 2012. We aimed to assess the coverage of school-based treatment (SBT) and community-wide treatment (CWT), to validate the coverage reported by the Zanzibar Ministry of Health (MoH) and to identify reasons for non-compliance. We conducted a post-MDA cross-sectional survey in 93 schools and 92 communities on Pemba and Unguja islands in early 2014, 3-5 months after the last MDA round. Pupils and adults were asked whether they had received and taken the praziquantel treatment provided in the last SBT or CWT, respectively, and the observed and reported coverage were compared. Reasons for non-compliance were recorded in a pretested questionnaire and assessed in qualitative interviews. Urine samples of participants were examined for Schistosoma haematobium eggs with a single urine filtration. Around 8000 pupils and 4000 adults were included in the analysis. Our survey revealed a SBT coverage of 85.2% in Pemba and of 86.9% in Unguja, which was in line with MoH reports from Pemba (84.3%) and higher than reports from Unguja (63.9%). However, 15 among the 48 schools surveyed in Unguja had not received SBT. Among the interviewed adults, 53.6% in Pemba and 64.9% in Unguja had received praziquantel during CWT, which was less than the 59.0% and 67.7%, respectively, indicated by MoH reports. Moreover, only 43.8% and 54.0% of adults in Pemba and Unguja, respectively, had taken all the tablets as recommended. The main reasons for not receiving or taking praziquantel were absence during CWT, no drug distributor coming, being busy, fear of adverse events, pregnancy, breastfeeding or feeling healthy. To increase coverage and compliance in Zanzibar, SBT should target all schools and mobilization, sensitization and implementation of the CWT need to be improved. To reach elimination of urogenital schistosomiasis transmission in Zanzibar and elsewhere, a very high treatment coverage and compliance at national and local level is key and additional control measures such as snail control and behaviour change interventions will need to be implemented area wide. ISRCTN48837681.
Hu, Yu; Chen, Yaping; Wang, Ying; Liang, Hui
2018-04-03
This study aimed to evaluate the potential achievable coverage of the second dose of measles containing vaccine (MCV2) when the protocol of simultaneous administration of childhood vaccines was fully implemented. Risk factors for missed opportunity (MO) for simultaneous administration of MCV2 were also investigated. Children born from 1 January 2005 to 31 December 2014 and registered in Zhejiang provincial immunization information system were enrolled in this study. The MO of simultaneous administration of MCV2, the actual age-appropriate coverage (AAC) of MCV2 and the potentially achievable coverage (PAC) of MCV2 were evaluated and compared across different birth cohorts, by different socio-demographic variables. For the 2014 birth cohort, logistic regression model was used to detect the risk factors of MOs, from both socio-demographic and vaccination service providing aspects. Compared to the AAC, the PAC of MCV2 increased significantly from 2005 birth cohort to 2014 birth cohort (p<0.001), with a median of 12.7 percentage points. Higher birth order of children, resident children, higher maternal education background, higher socio-economic development level of resident areas, less frequent vaccination service, and shorter vaccination service time were significant risk factors of MO for simultaneous administration of MCV2, with all p-value < 0.05. The findings in this study suggest that fully utilization of all opportunities for simultaneous administration of all age-eligible vaccine doses at the same vaccination visit is critical for achieving the coverage target of 95% for MCV2. Future interventions focusing on the group with risk factors observed could substantially eliminate MOs for simultaneous administration of MCV2, further to improve the coverage of fully immunization of MCV, and finally achieve the goal of eliminating measles.
Mereckiene, J; Cotter, S; Nicoll, A; Lopalco, P; Noori, T; Weber, Jt; D'Ancona, F; Levy-Bruhl, D; Dematte, L; Giambi, C; Valentiner-Branth, P; Stankiewicz, I; Appelgren, E; O Flanagan, D
2014-04-24
Since 2008, annual surveys of influenza vaccination policies, practices and coverage have been undertaken in 29 European Union (EU)/ European Economic Area (EEA) countries. After 2009, this monitored the impact of European Council recommendation to increase vaccination coverage to 75% among risk groups. This paper summarises the results of three seasonal influenza seasons: 2008/09, 2009/10 and 2010/11. In 2008/09, 27/29 countries completed the survey; in 2009/10 and 2010/11, 28/29 completed it. All or almost all countries recommended vaccination of older people (defined as those aged ≥50, ≥55, ≥59, ≥60 or ≥65 years), and people aged ≥6 months with clinical risk and healthcare workers. A total of 23 countries provided vaccination coverage data for older people, but only 7 and 10 had data for the clinical risk groups and healthcare workers, respectively. The number of countries recommending vaccination for some or all pregnant women increased from 10 in 2008/09 to 22 in 2010/11. Only three countries could report coverage among pregnant women. Seasonal influenza vaccination coverage during and after the pandemic season in older people and clinical groups remained unchanged in countries with higher coverage. However, small decreases were seen in most countries during this period. The results of the surveys indicate that most EU/EEA countries recommend influenza vaccination for the main target groups; however, only a few countries have achieved the target of 75% coverage among risk groups. Coverage among healthcare workers remained low.
Varan, Aiden K; Rodriguez-Lainz, Alfonso; Hill, Holly A; Elam-Evans, Laurie D; Yankey, David; Li, Qian
2017-08-01
Healthy People 2020 targets high vaccination coverage among children. Although reductions in coverage disparities by race/ethnicity have been described, data by nativity are limited. The National Immunization Survey is a random-digit-dialed telephone survey that estimates vaccination coverage among U.S. children aged 19-35 months. We assessed coverage among 52,441 children from pooled 2010-2012 data for individual vaccines and the combined 4:3:1:3*:3:1:4 series (which includes ≥4 doses of diphtheria, tetanus, and acellular pertussis vaccine/diphtheria and tetanus toxoids vaccine/diphtheria, tetanus toxoids, and pertussis vaccine, ≥3 doses of poliovirus vaccine, ≥1 dose of measles-containing vaccine, ≥3 or ≥4 doses of Haemophilus influenzae type b vaccine (depending on product type of vaccine; denoted as 3* in the series name), ≥3 doses of hepatitis B vaccine, ≥1 dose of varicella vaccine, and ≥4 doses of pneumococcal conjugate vaccine). Coverage estimates controlling for sociodemographic factors and multivariable logistic regression modeling for 4:3:1:3*:3:1:4 series completion are presented. Significantly lower coverage among foreign-born children was detected for DTaP, hepatitis A, hepatitis B, Hib, pneumococcal conjugate, and rotavirus vaccines, and for the combined series. Series completion disparities persisted after control for demographic, access-to-care, poverty, and language effects. Substantial and potentially widening disparities in vaccination coverage exist among foreign-born children. Improved immunization strategies targeting this population and continued vaccination coverage monitoring by nativity are needed.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Ma, C; Zhang, W; Lu, J
2015-06-15
Purpose: To compare the dosimetry of post modified radical mastectomy radiotherapy (PMRMRT) for left-sided breast cancer using 3-dimensional conformal radiotherapy (3DCRT), intensity-modulated radiation therapy (IMRT) and volumetric modulated arc therapy (VMAT). Methods: We created ten sets of PMRMRT plans for ten consecutive patients and utilized two tangential and one or two supraclavicular beams in 3DCRT, a total of 5 beams in IMRT and two optimized partial arcs in VMAT. The difference in results between any two of the three new plans, between new and previous 3DCRT plans were compared and analyzed by ANOVA (α =0.05) and paired-sample t-test respectively. Pmore » values less than 0.05 were considered statistically significant. Results: Both IMRT and VMAT plans had similar PTV coverage, hotspot area and conformity (all p>0.05), and significantly higher PTV coverage compared with new 3DCRT (both p<0.001). IMRT plans had significantly less heart and left lung radiation exposure compared with VMAT (all p<0.05). The 3DCRT plans with larger estimated CTV displacement had better target coverage but worse OARs sparing compared to those with smaller one. Conclusion: IMRT has dosimetrical advantages over the other two techniques in PMRMRT for left-sided breast cancer. Individually quantifying and minimizing CTV displacement can significantly improve dosage distribution. This work was supported by the Medical Scientific Research Foundation of Guangdong Procvince (A2014455 to Changchun Ma)« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Liu, B; Kim, J
Purpose: To compare the dosimetry of coplanar and non-coplanar RapidArc whole brain plans for hippocampal sparing Methods: We studied the RapidArc plans of patient with brain metastases, with the prescription of 3750 cGy in 15 fractions. The coplanar approach used a full clockwise (CW) arc and a full counterclockwise (CCW) arc, with the couch angle to be 0°. The non-coplanar approach used a full arc with a couch angle of 0°, and a partial arc with a couch angle of 90°. Treatment planning system is Eclipse Ver. 11. Constraints for eyes, lens, brainstem, optical nerves and chiasm are employed inmore » the optimization so that these OARs’ dose are below tolerance. Constraints for hippocampus are employed so that they receive dose as low as possible while maintain good coverage to whole brain. The beam delivery machine is Varian 21 IX. T1-weighted MRI images were used for hippocampus contouring. Results: The target coverage index for coplanar and non-coplanar RapidArc plans are 94.9% and 95.4%, respectively, with homogeneity index of 0.223 vs 0.226, which is defined as (D2% – D98%)/Dmean of target volume. V95 and V100 are 99.0% and 94.8% for coplanar plan, vs 99.1% and 95.4% for non-coplanar plan, while the mean dose of hippocampus are 1244.5 cGy for coplanar plan vs 1212.3 cGy for non-coplanar plan. Dose for eyes, lens, optical nerves, optical chiasm and brainstem are all below tolerance. Conclusion: Coplanar RapidArc plan provides good target coverage while achieves good hippocampal sparing, and there is no benefit to use non-coplanar approach.« less
NASA Astrophysics Data System (ADS)
Möller, Rebecca; Möller, Marco; Kukla, Peter A.; Schneider, Christoph
2018-01-01
We report results from a field experiment investigating the influence of volcanic tephra coverage on glacier ablation. These influences are known to be significantly different from those of moraine debris on glaciers due to the contrasting grain size distribution and thermal conductivity. Thus far, the influences of tephra deposits on glacier ablation have rarely been studied. For the experiment, artificial plots of two different tephra types from Eyjafjallajökull and Grímsvötn volcanoes were installed on a snow-covered glacier surface of Vatnajökull ice cap, Iceland. Snow-surface lowering and atmospheric conditions were monitored in summer 2015 and compared to a tephra-free reference site. For each of the two volcanic tephra types, three plots of variable thickness ( ˜ 1.5, ˜ 8.5 and ˜ 80 mm) were monitored. After limiting the records to a period of reliable measurements, a 50-day data set of hourly records was obtained, which can be downloaded from the Pangaea data repository (https://www.pangaea.de; doi:10.1594/PANGAEA.876656). The experiment shows a substantial increase in snow-surface lowering rates under the ˜ 1.5 and ˜ 8.5 mm tephra plots when compared to uncovered conditions. Under the thick tephra cover some insulating effects could be observed. These results are in contrast to other studies which depicted insulating effects for much thinner tephra coverage on bare-ice glacier surfaces. Differences between the influences of the two different petrological types of tephra exist but are negligible compared to the effect of tephra coverage overall.
Sources and Coverage of Medical News on Front Pages of US Newspapers
Lai, William Y. Y.; Lane, Trevor; Jones, Alison
2009-01-01
Background Medical news that appears on newspaper front pages is intended to reach a wide audience, but how this type of medical news is prepared and distributed has not been systematically researched. We thus quantified the level of visibility achieved by front-page medical stories in the United States and analyzed their news sources. Methodology Using the online resource Newseum, we investigated front-page newspaper coverage of four prominent medical stories, and a high-profile non-medical news story as a control, reported in the US in 2007. Two characteristics were quantified by two raters: which newspaper titles carried each target front-page story (interrater agreement, >96%; kappa, >0.92) and the news sources of each target story (interrater agreement, >94%; kappa, >0.91). National rankings of the top 200 US newspapers by audited circulation were used to quantify the extent of coverage as the proportion of the total circulation of ranked newspapers in Newseum. Findings In total, 1630 front pages were searched. Each medical story appeared on the front pages of 85 to 117 (67.5%–78.7%) ranked newspaper titles that had a cumulative daily circulation of 23.1 to 33.4 million, or 61.8% to 88.4% of all newspapers. In contrast, the non-medical story achieved front-page coverage in 152 (99.3%) newspaper titles with a total circulation of 41.0 million, or 99.8% of all newspapers. Front-page medical stories varied in their sources, but the Washington Post, Los Angeles Times, New York Times and the Associated Press together supplied 61.7% of the total coverage of target front-page medical stories. Conclusion Front-page coverage of medical news from different sources is more accurately revealed by analysis of circulation counts rather than of newspaper titles. Journals wishing to widen knowledge of research news and organizations with important health announcements should target at least the four dominant media organizations identified in this study. PMID:19724643
Vugmeyster, Yulia; Rohde, Cynthia; Perreault, Mylene; Gimeno, Ruth E; Singh, Pratap
2013-01-01
TAM-163, an agonist monoclonal antibody targeting tyrosine receptor kinase-B (TrkB), is currently being investigated as a potential body weight modulatory agent in humans. To support the selection of the dose range for the first-in-human (FIH) trial of TAM-163, we conducted a mechanistic analysis of the pharmacokinetic (PK) and pharmacodynamic (PD) data (e.g., body weight gain) obtained in lean cynomolgus and obese rhesus monkeys following single doses ranging from 0.3 to 60 mg/kg. A target-mediated drug disposition (TMDD) model was used to describe the observed nonlinear PK and Emax approach was used to describe the observed dose-dependent PD effect. The TMDD model development was supported by the experimental determination of the binding affinity constant (9.4 nM) and internalization rate of the drug-target complex (2.08 h(-1)). These mechanistic analyses enabled linking of exposure, target (TrkB) coverage, and pharmacological activity (e.g., PD) in monkeys, and indicated that ≥ 38% target coverage (time-average) was required to achieve significant body weight gain in monkeys. Based on the scaling of the TMDD model from monkeys to humans and assuming similar relationship between the target coverage and pharmacological activity between monkey and humans, subcutaneous (SC) doses of 1 and 15 mg/kg in humans were projected to be the minimally and the fully pharmacologically active doses, respectively. Based on the minimal anticipated biological effect level (MABEL) approach for starting dose selection, the dose of 0.05 mg/kg (3 mg for a 60 kg human) SC was recommended as the starting dose for FIH trials, because at this dose level<10% target coverage was projected at Cmax (and all other time points). This study illustrates a rational mechanistic approach for the selection of FIH dose range for a therapeutic protein with a complex model of action.
Metcalf, C J E; Tatem, A; Bjornstad, O N; Lessler, J; O'Reilly, K; Takahashi, S; Cutts, F; Grenfell, B T
2015-05-01
Measles vaccination is estimated to have averted 13·8 million deaths between 2000 and 2012. Persisting heterogeneity in coverage is a major contributor to continued measles mortality, and a barrier to measles elimination and introduction of rubella-containing vaccine. Our objective is to identify determinants of inequities in coverage, and how vaccine delivery must change to achieve elimination goals, which is a focus of the WHO Decade of Vaccines. We combined estimates of travel time to the nearest urban centre (⩾50 000 people) with vaccination data from Demographic Health Surveys to assess how remoteness affects coverage in 26 African countries. Building on a statistical mapping of coverage against age and geographical isolation, we quantified how modifying the rate and age range of vaccine delivery affects national coverage. Our scenario analysis considers increasing the rate of delivery of routine vaccination, increasing the target age range of routine vaccination, and enhanced delivery to remote areas. Geographical isolation plays a key role in defining vaccine inequity, with greater inequity in countries with lower measles vaccine coverage. Eliminating geographical inequities alone will not achieve thresholds for herd immunity, indicating that changes in delivery rate or age range of routine vaccination will be required. Measles vaccine coverage remains far below targets for herd immunity in many countries on the African continent and is likely to be inadequate for achieving rubella elimination. The impact of strategies such as increasing the upper age range eligible for routine vaccination should be considered.
Shi, Binbin; Wei, Wei; Wang, Yihuai; Shu, Wanneng
2016-01-01
In high-density sensor networks, scheduling some sensor nodes to be in the sleep mode while other sensor nodes remain active for monitoring or forwarding packets is an effective control scheme to conserve energy. In this paper, a Coverage-Preserving Control Scheduling Scheme (CPCSS) based on a cloud model and redundancy degree in sensor networks is proposed. Firstly, the normal cloud model is adopted for calculating the similarity degree between the sensor nodes in terms of their historical data, and then all nodes in each grid of the target area can be classified into several categories. Secondly, the redundancy degree of a node is calculated according to its sensing area being covered by the neighboring sensors. Finally, a centralized approximation algorithm based on the partition of the target area is designed to obtain the approximate minimum set of nodes, which can retain the sufficient coverage of the target region and ensure the connectivity of the network at the same time. The simulation results show that the proposed CPCSS can balance the energy consumption and optimize the coverage performance of the sensor network. PMID:27754405
Shi, Binbin; Wei, Wei; Wang, Yihuai; Shu, Wanneng
2016-10-14
In high-density sensor networks, scheduling some sensor nodes to be in the sleep mode while other sensor nodes remain active for monitoring or forwarding packets is an effective control scheme to conserve energy. In this paper, a Coverage-Preserving Control Scheduling Scheme (CPCSS) based on a cloud model and redundancy degree in sensor networks is proposed. Firstly, the normal cloud model is adopted for calculating the similarity degree between the sensor nodes in terms of their historical data, and then all nodes in each grid of the target area can be classified into several categories. Secondly, the redundancy degree of a node is calculated according to its sensing area being covered by the neighboring sensors. Finally, a centralized approximation algorithm based on the partition of the target area is designed to obtain the approximate minimum set of nodes, which can retain the sufficient coverage of the target region and ensure the connectivity of the network at the same time. The simulation results show that the proposed CPCSS can balance the energy consumption and optimize the coverage performance of the sensor network.
Granich, Reuben; Gupta, Somya; Hersh, Bradley; Williams, Brian; Montaner, Julio; Young, Benjamin; Zuniga, José M.
2015-01-01
Background Antiretroviral therapy (ART) prevents human immunodeficiency virus (HIV) disease progression, mortality and transmission. We assess the impact of expanded HIV treatment for the prevention of Acquired Immunodeficiency Syndrome (AIDS)-related deaths and simulate four treatment scenarios for Nigeria and South Africa. Methods For 1990–2013, we used the Joint United Nations Programme on HIV/AIDS (UNAIDS) database to examine trends in AIDS deaths, HIV incidence and prevalence, ART coverage, annual AIDS death rate, AIDS death-to-treatment and HIV infections to treatment ratios for the top 30 countries with the highest AIDS mortality burden and compare them with data from high-income countries. We projected the 1990–2020 AIDS deaths for Nigeria and South Africa using four treatment scenarios: 1) no ART; 2) maintaining current ART coverage; 3) 90% ART coverage based on 2013 World Health Organization (WHO) ART guidelines by 2020; and 4) reaching the United Nations 90-90-90 Target by 2020. Findings In 2013, there were 1.3 million (1.1 million–1.6 million) AIDS deaths in the top 30 countries representing 87% of global AIDS deaths. Eight countries accounted for 58% of the global AIDS deaths; Nigeria and South Africa accounted for 27% of global AIDS deaths. The highest death rates per 1000 people living with HIV were in Central African Republic (91), South Sudan (82), Côte d’Ivoire (75), Cameroon (72) and Chad (71), nearly 8–10 times higher than the high-income countries. ART access in 2013 has averted as estimated 1,051,354 and 422,448 deaths in South Africa and Nigeria, respectively. Increasing ART coverage in these two countries to meet the proposed UN 90-90-90 Target by 2020 could avert 2.2 and 1.2 million deaths, respectively. Interpretation Over the past decade the expansion of access to ART averted millions of deaths. Reaching the proposed UN 90-90-90 Target by 2020 will prevent additional morbidity, mortality and HIV transmission. Despite progress, high-burden countries will need to accelerate access to ART treatment to avert millions of premature AIDS deaths and new HIV infections. PMID:26147987
DOE Office of Scientific and Technical Information (OSTI.GOV)
Thomson, David J.; The University of Manchester, Manchester Academic Health Science Centre, Institute of Cancer Sciences, Manchester; Beasley, William J.
Introduction: Interfractional anatomical alterations may have a differential effect on the dose delivered by step-and-shoot intensity-modulated radiotherapy (IMRT) and volumetric-modulated arc therapy (VMAT). The increased degrees of freedom afforded by rotational delivery may increase plan robustness (measured by change in target volume coverage and doses to organs at risk [OARs]). However, this has not been evaluated for head and neck cancer. Materials and methods: A total of 10 patients who required repeat computed tomography (CT) simulation and replanning during head and neck IMRT were included. Step-and-shoot IMRT and VMAT plans were generated from the original planning scan. The initial andmore » second CT simulation scans were fused and targets/OAR contours transferred, reviewed, and modified. The plans were applied to the second CT scan and doses recalculated without repeat optimization. Differences between step-and-shoot IMRT and VMAT for change in target volume coverage and doses to OARs between first and second CT scans were compared by Wilcoxon signed rank test. Results: There were clinically relevant dosimetric changes between the first and the second CT scans for both the techniques (reduction in mean D{sub 95%} for PTV2 and PTV3, D{sub min} for CTV2 and CTV3, and increased mean doses to the parotid glands). However, there were no significant differences between step-and-shoot IMRT and VMAT for change in any target coverage parameter (including D{sub 95%} for PTV2 and PTV3 and D{sub min} for CTV2 and CTV3) or dose to any OARs (including parotid glands) between the first and the second CT scans. Conclusions: For patients with head and neck cancer who required replanning mainly due to weight loss, there were no significant differences in plan robustness between step-and-shoot IMRT and VMAT. This information is useful with increased clinical adoption of VMAT.« less
Progress Toward Universal Health Coverage: A Comparative Analysis in 5 South Asian Countries.
Rahman, Md Mizanur; Karan, Anup; Rahman, Md Shafiur; Parsons, Alexander; Abe, Sarah Krull; Bilano, Ver; Awan, Rabia; Gilmour, Stuart; Shibuya, Kenji
2017-09-01
Achieving universal health coverage is one of the key targets in the newly adopted Sustainable Development Goals of the United Nations. To investigate progress toward universal health coverage in 5 South Asian countries and assess inequalities in health services and financial risk protection indicators. In a population-based study, nationally representative household (335 373 households) survey data from Afghanistan (2014 and 2015), Bangladesh (2010 and 2014), India (2012 and 2014), Nepal (2014 and 2015), and Pakistan (2014) were used to calculate relative indices of health coverage, financial risk protection, and inequality in coverage among wealth quintiles. The study was conducted from June 2012 to February 2016. Three dimensions of universal health coverage were assessed: access to basic services, financial risk protection, and equity. Composite and indicator-specific coverage rates, stratified by wealth quintiles, were then estimated. Slope and relative index of inequality were used to assess inequalities in service and financial indicators. Access to basic care varied substantially across all South Asian countries, with mean rates of overall prevention coverage and treatment coverage of 53.0% (95% CI, 42.2%-63.6%) and 51.2% (95% CI, 45.2%-57.1%) in Afghanistan, 76.5% (95% CI, 61.0%-89.0%) and 44.8% (95% CI, 37.1%-52.5%) in Bangladesh, 74.2% (95% CI, 57.0%-88.1%) and 83.5% (95% CI, 54.4%-99.1%) in India, 76.8% (95% CI, 66.5%-85.7%) and 57.8% (95% CI, 50.1%-65.4%) in Nepal, and 69.8% (95% CI, 58.3%-80.2%) and 50.4% (95% CI, 37.1%-63.6%) in Pakistan. Financial risk protection was generally low, with 15.3% (95% CI, 14.7%-16.0%) of respondents in Afghanistan, 15.8% (95% CI, 14.9%-16.8%) in Bangladesh, 17.9% (95% CI, 17.7%-18.2%) in India, 11.8% (95% CI, 11.8%-11.9%) in Nepal, and 4.4% (95% CI, 4.0%-4.9%) in Pakistan reporting incurred catastrophic payments due to health care costs. Access to at least 4 antenatal care visits, institutional delivery, and presence of skilled attendant during delivery were at least 3 times higher among the wealthiest mothers in Afghanistan, Bangladesh, Nepal, and Pakistan compared with the rates among poor mothers. Access to institutional delivery was 60 to 65 percentage points higher among wealthy than poor mothers in Afghanistan, Bangladesh, Nepal, and Pakistan compared with 21 percentage points higher in India. Coverage was least equitable among the countries for adequate sanitation, institutional delivery, and the presence of skilled birth attendants. Health coverage and financial risk protection was low, and inequality in access to health care remains a serious issue for these South Asian countries. Greater progress is needed to improve treatment and preventive services and financial security.
Strogatz, D S; James, S A; Elliott, D; Ramsey, D; Cutchin, L M; Ibrahim, M A
1985-01-01
In a rural, church-based hypertension program in Edgecombe County, North Carolina, screening of the congregations was complemented by a community outreach component targeted at 18-60 year old males, a group at higher risk for untreated hypertension. Compared with its estimated frequency in the community, untreated hypertension was as common in the church congregations and somewhat less prevalent than expected among outreach screenees. PMID:3976968
[Benchmarking of performance of Mexican states with effective coverage].
Lozano, Rafael; Soliz, Patricia; Gakidou, Emmanuela; Abbott-Klafter, Jesse; Feehan, Dennis M; Vidal, Cecilia; Ortiz, Juan Pablo; Murray, Christopher J L
2007-01-01
Benchmarking of the performance of states, provinces, or districts in a decentralised health system is important for fostering of accountability, monitoring of progress, identification of determinants of success and failure, and creation of a culture of evidence. The Mexican Ministry of Health has, since 2001, used a benchmarking approach based on the World Health Organization (WHO) concept of effective coverage of an intervention, which is defined as the proportion of potential health gain that could be delivered by the health system to that which is actually delivered. Using data collection systems, including state representative examination surveys, vital registration, and hospital discharge registries, we have monitored the delivery of 14 interventions for 2005-06. Overall effective coverage ranges from 54.0% in Chiapas, a poor state, to 65.1% in the Federal District. Effective coverage for maternal and child health interventions is substantially higher than that for interventions that target other health problems. Effective coverage for the lowest wealth quintile is 52% compared with 61% for the highest quintile. Effective coverage is closely related to public-health spending per head across states; this relation is stronger for interventions that are not related to maternal and child health than those for maternal and child health. Considerable variation also exists in effective coverage at similar amounts of spending. We discuss the implications of these issues for the further development of the Mexican health-information system. Benchmarking of performance by measuring effective coverage encourages decision-makers to focus on quality service provision, not only service availability. The effective coverage calculation is an important device for health-system stewardship. In adopting this approach, other countries should select interventions to be measured on the basis of the criteria of affordability, effect on population health, effect on health inequalities, and capacity to measure the effects of the intervention. The national institutions undertaking this benchmarking must have the mandate, skills, resources, and independence to succeed.
Benchmarking of performance of Mexican states with effective coverage.
Lozano, Rafael; Soliz, Patricia; Gakidou, Emmanuela; Abbott-Klafter, Jesse; Feehan, Dennis M; Vidal, Cecilia; Ortiz, Juan Pablo; Murray, Christopher J L
2006-11-11
Benchmarking of the performance of states, provinces, or districts in a decentralised health system is important for fostering of accountability, monitoring of progress, identification of determinants of success and failure, and creation of a culture of evidence. The Mexican Ministry of Health has, since 2001, used a benchmarking approach based on the WHO concept of effective coverage of an intervention, which is defined as the proportion of potential health gain that could be delivered by the health system to that which is actually delivered. Using data collection systems, including state representative examination surveys, vital registration, and hospital discharge registries, we have monitored the delivery of 14 interventions for 2005-06. Overall effective coverage ranges from 54.0% in Chiapas, a poor state, to 65.1% in the Federal District. Effective coverage for maternal and child health interventions is substantially higher than that for interventions that target other health problems. Effective coverage for the lowest wealth quintile is 52% compared with 61% for the highest quintile. Effective coverage is closely related to public-health spending per head across states; this relation is stronger for interventions that are not related to maternal and child health than those for maternal and child health. Considerable variation also exists in effective coverage at similar amounts of spending. We discuss the implications of these issues for the further development of the Mexican health-information system. Benchmarking of performance by measuring effective coverage encourages decision-makers to focus on quality service provision, not only service availability. The effective coverage calculation is an important device for health-system stewardship. In adopting this approach, other countries should select interventions to be measured on the basis of the criteria of affordability, effect on population health, effect on health inequalities, and capacity to measure the effects of the intervention. The national institutions undertaking this benchmarking must have the mandate, skills, resources, and independence to succeed.
Jiménez-García, Rodrigo; Hernandez-Barrera, Valentín; Rodríguez-Rieiro, Cristina; Carrasco Garrido, Pilar; López de Andres, Ana; Jimenez-Trujillo, Isabel; Esteban-Vasallo, María D; Domínguez-Berjón, Maria Felicitas; de Miguel-Diez, Javier; Astray-Mochales, Jenaro
2014-07-31
We aim to compare influenza vaccination coverages obtained using two different methods; a population based computerized vaccination registry and self-reported influenza vaccination status as captured by a population survey. The study was conducted in the Autonomous Community of Madrid (ACM), Spain, and refers to the 2011/12 influenza vaccination campaign. Information on influenza vaccination status according to a computerized registry was extracted from the SISPAL database and crossed with the electronic clinical records in primary care (ECRPC). Self-reported vaccine uptake was obtained from subjects living in the ACM included in the 2011-12 Spanish National Health Survey (SNHS). Independent study variables included: age, sex, immigrant status and the presence of high risk chronic conditions. Vaccination coverages were calculated according to study variables. Crude and adjusted prevalence ratios were computed to assess concordance. The study population included 5,245,238 adults living in the ACM in year 2011 with an individual ECRPC and 1449 adult living the ACM and interviewed in the SNHS from October 2011 to June 2012. The weighted vaccination coverage for the study population according to self-reported data was 19.77% and 15.04% from computerized registries resulting in a crude prevalence ratio (cPR) of 1.31 (95% CI 1.20-1.44) so self-reported data significantly overestimated 31% the registry coverage. Self-reported coverages are always higher than registry based coverages when the study population is stratified by the study variables. Self-reported overestimation was higher among men than women, younger age groups, immigrants and those without chronic conditions. Both methods provide the most concordant estimations for the target population of the influenza vaccine. Self-report influenza vaccination uptake overestimates vaccination registries coverages. The validity of self-report seems to be negatively affected by socio-demographic variables and the absence of chronic conditions. Possible strategies must be considered and implemented to improve both coverage estimation methods. Copyright © 2014 Elsevier Ltd. All rights reserved.
Ahanhanzo, Y Glèlè; Palenfo, D; Saussier, C; Gbèdonou, P; Tonda, A; Da Silva, A; Aplogan, A
2016-08-01
Within the framework of its strategic goal of vaccine coverage (VC) improvement, GAVI, The Vaccine Alliance has entrusted the Agence de médecine préventive (agency for preventive medicine, AMP) with technical assistance services to Cameroon, Cote d'Ivoire (Ivory Coast), and Mauritania. This support was provided to selected priority districts (PDs) with the worst Penta3 coverage performances. In 2014, PDs benefited from technical and management capacities in vaccinology strengthening for district medical officers, supportive supervisions and technical assistance in health logistics, data management and quality. We analyzed the effects of the AMP technical assistance on the improvement of the cumulative Penta3 coverage, which is the key performance indicator of the expanded programme on immunization (EPI) performance. We compared Penta3 coverage between PDs and other non-priority districts (NPDs), Penta3 coverage evolution within each PD, and the distribution of PDs and NPDs according to Penta3 coverage category between January and December 2014. Technical assistance had a positive effect on the EPI performance. Indeed Penta3 coverage progression was higher in PDs than in NPDs throughout the period. Besides, between January and December 2014, the Penta3 VC increased in 70%, 100% and 86% of DPs in Cameroon, Côte d'Ivoire and Mauritania, respectively. Furthermore, the increase in the number of PDs with a Penta3 coverage over 80% was higher in DPs than in NPDs: 20% versus 8% for Cameroon, 58% versus 29% for Côte d'Ivoire and 17% versus 8% for Mauritania. Despite positive and encouraging results, this technical assistance service can be improved and efforts are needed to ensure that all health districts have a VC above 80% for all EPI vaccines. The current challenge is for African countries to mobilize resources for maintaining the knowledge and benefits and scaling such interventions in the public health area.
Ropero-Álvarez, Alba María; El Omeiri, Nathalie; Kurtis, Hannah Jane; Danovaro-Holliday, M. Carolina; Ruiz-Matus, Cuauhtémoc
2016-01-01
ABSTRACT Background: There has been considerable uptake of seasonal influenza vaccines in the Americas compared to other regions. We describe the current influenza vaccination target groups, recent progress in vaccine uptake and in generating evidence on influenza seasonality and vaccine effectiveness for immunization programs. We also discuss persistent challenges, 5 years after the A(H1N1) 2009 influenza pandemic. Methods: We compiled and summarized data annually reported by countries to the Pan American Health Organization/World Health Organization (PAHO/WHO) through the WHO/UNICEF joint report form on immunization, information obtained through PAHO's Revolving Fund for Vaccine Procurement and communications with managers of national Expanded Programs on Immunization (EPI). Results: Since 2008, 25 countries/territories in the Americas have introduced new target groups for vaccination or expanded the age ranges of existing target groups. As of 2014, 40 (89%) out of 45 countries/territories have policies established for seasonal influenza vaccination. Currently, 29 (64%) countries/territories target pregnant women for vaccination, the highest priority group according to WHO´s Stategic Advisory Group of Experts and PAHO/WHO's Technical Advisory Group on Vaccine-preventable Diseases, compared to only 7 (16%) in 2008. Among 23 countries reporting coverage data, on average, 75% of adults ≥60 years, 45% of children aged 6–23 months, 32% of children aged 5–2 years, 59% of pregnant women, 78% of healthcare workers, and 90% of individuals with chronic conditions were vaccinated during the 2013–14 Northern Hemisphere or 2014 Southern Hemisphere influenza vaccination activities. Difficulties however persist in the estimation of vaccination coverage, especially for pregnant women and persons with chronic conditions. Since 2007, 6 tropical countries have changed their vaccine formulation from the Northern to the Southern Hemisphere formulation and the timing of their campaigns to April-May following the review of national evidence. LAC countries have also established an official network dedicated to evaluating influenza vaccines effectiveness and impact. Conclusion: Following the A(H1N1)2009 influenza pandemic, countries of the Americas have continued their efforts to sustain or increase seasonal influenza vaccine uptake among high risk groups, especially among pregnant women. Countries also continued strengthening influenza surveillance, immunization platforms and information systems, indirectly improving preparedness for future pandemics. Influenza vaccination is particularly challenging compared to other vaccines included in EPI schedules, due to the need for annual, optimally timed vaccination, the wide spectrum of target groups, and the limitations of the available vaccines. Countries should continue to monitor influenza vaccination coverage, generate evidence for vaccination programs and implement social communication strategies addressing existing gaps. PMID:27196006
Ropero-Álvarez, Alba María; El Omeiri, Nathalie; Kurtis, Hannah Jane; Danovaro-Holliday, M Carolina; Ruiz-Matus, Cuauhtémoc
2016-08-02
There has been considerable uptake of seasonal influenza vaccines in the Americas compared to other regions. We describe the current influenza vaccination target groups, recent progress in vaccine uptake and in generating evidence on influenza seasonality and vaccine effectiveness for immunization programs. We also discuss persistent challenges, 5 years after the A(H1N1) 2009 influenza pandemic. We compiled and summarized data annually reported by countries to the Pan American Health Organization/World Health Organization (PAHO/WHO) through the WHO/UNICEF joint report form on immunization, information obtained through PAHO's Revolving Fund for Vaccine Procurement and communications with managers of national Expanded Programs on Immunization (EPI). Since 2008, 25 countries/territories in the Americas have introduced new target groups for vaccination or expanded the age ranges of existing target groups. As of 2014, 40 (89%) out of 45 countries/territories have policies established for seasonal influenza vaccination. Currently, 29 (64%) countries/territories target pregnant women for vaccination, the highest priority group according to WHO´s Stategic Advisory Group of Experts and PAHO/WHO's Technical Advisory Group on Vaccine-preventable Diseases, compared to only 7 (16%) in 2008. Among 23 countries reporting coverage data, on average, 75% of adults ≥60 years, 45% of children aged 6-23 months, 32% of children aged 5-2 years, 59% of pregnant women, 78% of healthcare workers, and 90% of individuals with chronic conditions were vaccinated during the 2013-14 Northern Hemisphere or 2014 Southern Hemisphere influenza vaccination activities. Difficulties however persist in the estimation of vaccination coverage, especially for pregnant women and persons with chronic conditions. Since 2007, 6 tropical countries have changed their vaccine formulation from the Northern to the Southern Hemisphere formulation and the timing of their campaigns to April-May following the review of national evidence. LAC countries have also established an official network dedicated to evaluating influenza vaccines effectiveness and impact. Following the A(H1N1)2009 influenza pandemic, countries of the Americas have continued their efforts to sustain or increase seasonal influenza vaccine uptake among high risk groups, especially among pregnant women. Countries also continued strengthening influenza surveillance, immunization platforms and information systems, indirectly improving preparedness for future pandemics. Influenza vaccination is particularly challenging compared to other vaccines included in EPI schedules, due to the need for annual, optimally timed vaccination, the wide spectrum of target groups, and the limitations of the available vaccines. Countries should continue to monitor influenza vaccination coverage, generate evidence for vaccination programs and implement social communication strategies addressing existing gaps.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Parker, William; Filion, Edith; Roberge, David
2007-09-01
Purpose: To report the results of an analysis of dose received to tissues and organs outside the target volume, in the setting of spinal axis irradiation for the treatment of medulloblastoma, using three treatment techniques. Methods and Materials: Treatment plans (total dose, 23.4 Gy) for a standard two-dimensional (2D) technique, a three-dimensional (3D) technique using a 3D imaging-based target volume, and an intensity-modulated radiotherapy (IMRT) technique, were compared for 3 patients in terms of dose-volume statistics for target coverage, as well as organ at risk (OAR) and overall tissue sparing. Results: Planning target volume coverage and dose homogeneity was superiormore » for the IMRT plans for V{sub 95%} (IMRT, 100%; 3D, 96%; 2D, 98%) and V{sub 107%} (IMRT, 3%; 3D, 38%; 2D, 37%). In terms of OAR sparing, the IMRT plan was better for all organs and whole-body contour when comparing V{sub 10Gy}, V{sub 15Gy}, and V{sub 20Gy}. The 3D plan was superior for V{sub 5Gy} and below. For the heart and liver in particular, the IMRT plans provided considerable sparing in terms of V{sub 10Gy} and above. In terms of the integral dose, the IMRT plans were superior for liver (IMRT, 21.9 J; 3D, 28.6 J; 2D, 38.6 J) and heart (IMRT, 9 J; 3D, 14.1J; 2D, 19.4 J), the 3D plan for the body contour (IMRT, 349 J; 3D, 337 J; 2D, 555 J). Conclusions: Intensity-modulated radiotherapy is a valid treatment option for spinal axis irradiation. We have shown that IMRT results in sparing of organs at risk without a significant increase in integral dose.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Hadsell, M; Xing, L; Bush, K
We propose a new type of treatment that employs a modulated tangential photon field to provide superior coverage of complex superficial targets when compared to other commonly employed methods, and drastically reduce dose to the underlying sensitive structures often present in these cases. TMAT plans were formulated for a set of four representative cases: 1. Scalp sarcoma, 2. Posterior chest-wall sarcoma, 3. Pleural mesothelioma with intact lung, 4. Chest-wall with deep inframammary nodes. For these cases, asymmetric jaw placement, angular limitations, and central isocenter placements were used to force optimization solutions with beam lines tangential to the body surface. Whenmore » compared with unrestricted modulated arcs, the tangential arc scalp treatment reduced the max and mean doses delivered to the brain by 33Gy (from 55Gy to 22Gy) and 6Gy (from 14Gy to 8Gy), respectively. In the posterior chest wall case, the V10 for the ipsilateral lung was kept below 5% impressively while retaining the 45Gy target prescription coverage by over 97%. For the breast chest-wall case, the TMAT plan achieved reductions in high dose to the ipsilateral lung and heart by a factor of 2–3 when compared to classic, laterally opposed, tangents and reduced the V5 by 40% when compared to standard modulated arcs. TMAT has outperformed the conventional modalities of treatment for superficial lesions used in our clinic. We hope that with the advent of digitally controlled linear accelerators, we can uncover further benefits of this new technique and extend its applicability to a wider section of the patient population.« less
Bijl, Hendrik P.; Schilstra, Cornelis; Pijls-Johannesma, Madelon; Langendijk, Johannes A.
2011-01-01
Purpose. Clinical studies concerning head and neck cancer patients treated with protons reporting on radiation-induced side effects are scarce. Therefore, we reviewed the literature regarding the potential benefits of protons compared with the currently used photons in terms of lower doses to normal tissue and the potential for fewer subsequent radiation-induced side effects, with the main focus on in silico planning comparative (ISPC) studies. Materials and Methods. A literature search was performed by two independent researchers on ISPC studies that included proton-based and photon-based irradiation techniques. Results. Initially, 877 papers were retrieved and 14 relevant and eligible ISPC studies were identified and included in this review. Four studies included paranasal sinus cancer cases, three included nasopharyngeal cancer cases, and seven included oropharyngeal, hypopharyngeal, and/or laryngeal cancer cases. Seven studies compared the most sophisticated photon and proton techniques: intensity-modulated photon therapy versus intensity-modulated proton therapy (IMPT). Four studies compared different proton techniques. All studies showed that protons had a lower normal tissue dose, while keeping similar or better target coverage. Two studies found that these lower doses theoretically translated into a significantly lower incidence of salivary dysfunction. Conclusion. The results of ISPC studies indicate that protons have the potential for a significantly lower normal tissue dose, while keeping similar or better target coverage. Scanned IMPT probably offers the most advantage and will allow for a substantially lower probability of radiation-induced side effects. The results of these ISPC studies should be confirmed in properly designed clinical trials. PMID:21349950
Golberstein, Ezra; Busch, Susan H.; Zaha, Rebecca; Greenfield, Shelly F.; Beardslee, William R.; Meara, Ellen
2014-01-01
Objective Insurance coverage for young adults has increased since 2010, when the Affordable Care Act (ACA) required insurers to permit children on parental policies until age 26 as dependents. This study estimated changes in young adults’ use of hospital-based services with diagnosis codes for mental illness and substance abuse associated with the dependent coverage provision. Method Quasi-experimental comparison of national sample of non-birth hospital inpatient admissions to general hospitals (n=2,670,463 total, n=430,583 with primary behavioral health diagnosis) and California emergency department (ED) visits with behavioral health diagnoses (n=11,139,689). Data spanned 2005 to 2011. Estimates compared young adults who were and were not targeted by the ACA dependent coverage provision (19 to 25 versus 26 to 29 year olds), estimating changes in utilization before and after 2010. Primary outcomes included: quarterly inpatient admissions for primary diagnosis of any behavioral health disorder per 1000 population; ED visits with any behavioral health diagnosis per 1000 population; and payer source. Results Dependent coverage expansion was associated with 0.14 per 1000 more (p<0.001) inpatient admissions for behavioral health for 19-25 (ACA covered) versus 26-29 (then ACA uncovered) year olds. The coverage expansion was associated with 0.45 fewer behavioral health ED visits per 1000 (p=0.001) in California. The probability that inpatient admissions nationally, and ED visits in California were uninsured, decreased significantly (p<0.001). Conclusions ACA dependent coverage provisions produced modest increases in general hospital psychiatric inpatient admissions and higher rates of insurance coverage for young adult children nationally. Lower ED visit rates were observed in California. PMID:25263817
Liu, Zhong; Gao, Xiaoguang; Fu, Xiaowei
2018-05-08
In this paper, we mainly study a cooperative search and coverage algorithm for a given bounded rectangle region, which contains several unknown stationary targets, by a team of unmanned aerial vehicles (UAVs) with non-ideal sensors and limited communication ranges. Our goal is to minimize the search time, while gathering more information about the environment and finding more targets. For this purpose, a novel cooperative search and coverage algorithm with controllable revisit mechanism is presented. Firstly, as the representation of the environment, the cognitive maps that included the target probability map (TPM), the uncertain map (UM), and the digital pheromone map (DPM) are constituted. We also design a distributed update and fusion scheme for the cognitive map. This update and fusion scheme can guarantee that each one of the cognitive maps converges to the same one, which reflects the targets’ true existence or absence in each cell of the search region. Secondly, we develop a controllable revisit mechanism based on the DPM. This mechanism can concentrate the UAVs to revisit sub-areas that have a large target probability or high uncertainty. Thirdly, in the frame of distributed receding horizon optimizing, a path planning algorithm for the multi-UAVs cooperative search and coverage is designed. In the path planning algorithm, the movement of the UAVs is restricted by the potential fields to meet the requirements of avoiding collision and maintaining connectivity constraints. Moreover, using the minimum spanning tree (MST) topology optimization strategy, we can obtain a tradeoff between the search coverage enhancement and the connectivity maintenance. The feasibility of the proposed algorithm is demonstrated by comparison simulations by way of analyzing the effects of the controllable revisit mechanism and the connectivity maintenance scheme. The Monte Carlo method is employed to validate the influence of the number of UAVs, the sensing radius, the detection and false alarm probabilities, and the communication range on the proposed algorithm.
Frey, Allison; Mika, Stephanie; Nuzum, Rachel; Schoen, Cathy
2009-06-01
Many proposed health insurance reforms would establish a federal minimum benefit standard--a baseline set of benefits to ensure that people have adequate coverage and financial protection when they purchase insurance. Currently, benefit mandates are set at the state level; these vary greatly across states and generally target specific areas rather than set an overall standard for what qualifies as health insurance. This issue brief considers what a broad federal minimum standard might look like by comparing existing state benefit mandates with the services and providers covered under the Federal Employees Health Benefits Program (FEHBP) Blue Cross and Blue Shield standard benefit package, an example of minimum creditable coverage that reflects current standard practice among employer-sponsored health plans. With few exceptions, benefits in the FEHBP standard option either meet or exceed those that state mandates require-indicating that a broad-based national benefit standard would include most existing state benefit mandates.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Zheng, D; Zhang, Q; Zhou, S
Purpose: To investigate the impact of normalized prescription isodose line on target dose deficiency calculated with Monte Carlo (MC) vs. pencil Beam (PB) in lung SBRT. RTOG guidelines recommend prescription lines between 60% and 90% for lung SBRT. How this affects the magnitude of MC-calculated target dose deficiency has never been studied. Methods: Under an IRB-approved protocol, four lung SBRT patients were replanned following RTOG0813 by a single physicist. For each patient, four alternative plans were generated based on PB calculation prescribing to 60–90% isodose lines, respectively. Each plan consisted of 360o coplanar dynamic conformal arcs with beam apertures manuallymore » optimized to achieve similar dose coverage and conformity for all plans of the same patient. Dose distribution was calculated with MC and compared to that with PB. PTV dose-volume endpoints were compared, including Dmin, D5, Dmean, D95, and Dmax. PTV V100 coverage, conformity index (CI), and heterogeneity index (HI) were also evaluated. Results: For all 16 plans, median (range) PTV V100 and CI were 99.7% (97.5–100%) and 1.27 (1.20–1.41), respectively. As expected, lower prescription line resulted in higher target dose heterogeneity, yielding median (range) HI of 1.26 (1.05–1.51) for all plans. Comparing MC to PB, median (range) D95, Dmean, D5 PTV dose deficiency were 18.9% (11.2–23.2%), 15.6% (10.0–22.7%), and 9.4%(5.5–13.6%) of the prescription dose, respectively. The Dmean, D5, and Dmax deficiency was found to monotonically increase with decreasing prescription line from 90% to 60%, while the Dmin deficiency monotonically decreased. D95 deficiency exhibited more complex trend, reaching the largest deficiency at 80% for all patients. Conclusion: Dependence on prescription isodose line was found for MC-calculated PTV dose deficiency of lung SBRT. When comparing reported MC dose deficiency values from different institutions, their individual selections of prescription line should be considered in addition to other factors affecting the deficiency magnitude.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Sakanaka, Katsuyuki; Mizowaki, Takashi, E-mail: mizo@kuhp.kyoto-u.ac.jp; Sato, Sayaka
This study evaluated the dosimetric difference between volumetric-modulated arc therapy (VMAT) and conventional fixed-field intensity-modulated radiotherapy (cIMRT) in whole-ventricular irradiation. Computed tomography simulation data for 13 patients were acquired to create plans for VMAT and cIMRT. In both plans, the same median dose (100% = 24 Gy) was prescribed to the planning target volume (PTV), which comprised a tumor bed and whole ventricles. During optimization, doses to the normal brain and body were reduced, provided that the dose constraints of the target coverage were satisfied. The dose-volume indices of the PTV, normal brain, and body as well as monitor unitsmore » were compared between the 2 techniques by using paired t-tests. The results showed no significant difference in the homogeneity index (0.064 vs 0.065; p = 0.824) of the PTV and conformation number (0.78 vs 0.77; p = 0.065) between the 2 techniques. In the normal brain and body, the dose-volume indices showed no significant difference between the 2 techniques, except for an increase in the volume receiving a low dose in VMAT; the absolute volume of the normal brain and body receiving 1 Gy of radiation significantly increased in VMAT by 1.6% and 8.3%, respectively, compared with that in cIMRT (1044 vs 1028 mL for the normal brain and 3079.2 vs 2823.3 mL for the body; p<0.001). The number of monitor units to deliver a 2.0-Gy fraction was significantly reduced in VMAT compared with that in cIMRT (354 vs 873, respectively; p<0.001). In conclusion, VMAT delivers IMRT to complex target volumes such as whole ventricles with fewer monitor units, while maintaining target coverage and conformal isodose distribution comparable to cIMRT; however, in addition to those characteristics, the fact that the volume of the normal brain and body receiving a low dose would increase in VMAT should be considered.« less
Increasing influenza vaccination coverage in recommended population groups in Europe.
Blank, Patricia R; Szucs, Thomas D
2009-04-01
The clinical and economic burden of seasonal influenza is frequently underestimated. The cornerstone of controlling and preventing influenza is vaccination. National and international guidelines aim to implement immunization programs and targeted vaccination-coverage rates, which should help to enhance the vaccine uptake, especially in the at-risk population. This review purposes to highlight the vaccination guidelines and the actual vaccination situation in four target groups (the elderly, people with underlying chronic conditions, healthcare workers and children) from a European point of view.
NASA Astrophysics Data System (ADS)
Houweling, Antonetta C.; Crama, Koen; Visser, Jorrit; Fukata, Kyohei; Rasch, Coen R. N.; Ohno, Tatsuya; Bel, Arjan; van der Horst, Astrid
2017-04-01
Radiotherapy using charged particles is characterized by a low dose to the surrounding healthy organs, while delivering a high dose to the tumor. However, interfractional anatomical changes can greatly affect the robustness of particle therapy. Therefore, we compared the dosimetric impact of interfractional anatomical changes (i.e. body contour differences and gastrointestinal gas volume changes) in photon, proton and carbon ion therapy for pancreatic cancer patients. In this retrospective planning study, photon, proton and carbon ion treatment plans were created for 9 patients. Fraction dose calculations were performed using daily cone-beam CT (CBCT) images. To this end, the planning CT was deformably registered to each CBCT; gastrointestinal gas volumes were delineated on the CBCTs and copied to the deformed CT. Fraction doses were accumulated rigidly. To compare planned and accumulated dose, dose-volume histogram (DVH) parameters of the planned and accumulated dose of the different radiotherapy modalities were determined for the internal gross tumor volume, internal clinical target volume (iCTV) and organs-at-risk (OARs; duodenum, stomach, kidneys, liver and spinal cord). Photon plans were highly robust against interfractional anatomical changes. The difference between the planned and accumulated DVH parameters for the photon plans was less than 0.5% for the target and OARs. In both proton and carbon ion therapy, however, coverage of the iCTV was considerably reduced for the accumulated dose compared with the planned dose. The near-minimum dose ({{D}98 % } ) of the iCTV reduced with 8% for proton therapy and with 10% for carbon ion therapy. The DVH parameters of the OARs differed less than 3% for both particle modalities. Fractionated radiotherapy using photons is highly robust against interfractional anatomical changes. In proton and carbon ion therapy, such changes can severely reduce the dose coverage of the target.
Increasing the structural coverage of tuberculosis drug targets.
Baugh, Loren; Phan, Isabelle; Begley, Darren W; Clifton, Matthew C; Armour, Brianna; Dranow, David M; Taylor, Brandy M; Muruthi, Marvin M; Abendroth, Jan; Fairman, James W; Fox, David; Dieterich, Shellie H; Staker, Bart L; Gardberg, Anna S; Choi, Ryan; Hewitt, Stephen N; Napuli, Alberto J; Myers, Janette; Barrett, Lynn K; Zhang, Yang; Ferrell, Micah; Mundt, Elizabeth; Thompkins, Katie; Tran, Ngoc; Lyons-Abbott, Sally; Abramov, Ariel; Sekar, Aarthi; Serbzhinskiy, Dmitri; Lorimer, Don; Buchko, Garry W; Stacy, Robin; Stewart, Lance J; Edwards, Thomas E; Van Voorhis, Wesley C; Myler, Peter J
2015-03-01
High-resolution three-dimensional structures of essential Mycobacterium tuberculosis (Mtb) proteins provide templates for TB drug design, but are available for only a small fraction of the Mtb proteome. Here we evaluate an intra-genus "homolog-rescue" strategy to increase the structural information available for TB drug discovery by using mycobacterial homologs with conserved active sites. Of 179 potential TB drug targets selected for x-ray structure determination, only 16 yielded a crystal structure. By adding 1675 homologs from nine other mycobacterial species to the pipeline, structures representing an additional 52 otherwise intractable targets were solved. To determine whether these homolog structures would be useful surrogates in TB drug design, we compared the active sites of 106 pairs of Mtb and non-TB mycobacterial (NTM) enzyme homologs with experimentally determined structures, using three metrics of active site similarity, including superposition of continuous pharmacophoric property distributions. Pair-wise structural comparisons revealed that 19/22 pairs with >55% overall sequence identity had active site Cα RMSD <1 Å, >85% side chain identity, and ≥80% PSAPF (similarity based on pharmacophoric properties) indicating highly conserved active site shape and chemistry. Applying these results to the 52 NTM structures described above, 41 shared >55% sequence identity with the Mtb target, thus increasing the effective structural coverage of the 179 Mtb targets over three-fold (from 9% to 32%). The utility of these structures in TB drug design can be tested by designing inhibitors using the homolog structure and assaying the cognate Mtb enzyme; a promising test case, Mtb cytidylate kinase, is described. The homolog-rescue strategy evaluated here for TB is also generalizable to drug targets for other diseases. Copyright © 2014 Elsevier Ltd. All rights reserved.
Increasing the structural coverage of tuberculosis drug targets
DOE Office of Scientific and Technical Information (OSTI.GOV)
Baugh, Loren; Phan, Isabelle; Begley, Darren W.
High-resolution three-dimensional structures of essential Mycobacterium tuberculosis (Mtb) proteins provide templates for TB drug design, but are available for only a small fraction of the Mtb proteome. Here we evaluate an intra-genus “homolog-rescue” strategy to increase the structural information available for TB drug discovery by using mycobacterial homologs with conserved active sites. We found that of 179 potential TB drug targets selected for x-ray structure determination, only 16 yielded a crystal structure. By adding 1675 homologs from nine other mycobacterial species to the pipeline, structures representing an additional 52 otherwise intractable targets were solved. To determine whether these homolog structuresmore » would be useful surrogates in TB drug design, we compared the active sites of 106 pairs of Mtb and non-TB mycobacterial (NTM) enzyme homologs with experimentally determined structures, using three metrics of active site similarity, including superposition of continuous pharmacophoric property distributions. Pair-wise structural comparisons revealed that 19/22 pairs with >55% overall sequence identity had active site Cα RMSD <1 Å, >85% side chain identity, and ≥80% PS APF (similarity based on pharmacophoric properties) indicating highly conserved active site shape and chemistry. Applying these results to the 52 NTM structures described above, 41 shared >55% sequence identity with the Mtb target, thus increasing the effective structural coverage of the 179 Mtb targets over three-fold (from 9% to 32%). The utility of these structures in TB drug design can be tested by designing inhibitors using the homolog structure and assaying the cognate Mtb enzyme; a promising test case, Mtb cytidylate kinase, is described. The homolog-rescue strategy evaluated here for TB is also generalizable to drug targets for other diseases.« less
Eisbruch, A; Dawson, L A; Kim, H M; Bradford, C R; Terrell, J E; Chepeha, D B; Teknos, T N; Anzai, Y; Marsh, L H; Martel, M K; Ten Haken, R K; Wolf, G T; Ship, J A
1999-01-01
To develop techniques which facilitate sparing of the major salivary glands while adequately treating the targets in patients requiring comprehensive bilateral neck irradiation (RT). Conformal and static, multisegmental intensity modulated (IMRT) techniques have been developed. The salivary flow rates before and periodically after RT have been measured selectively from each major salivary gland and the residual flows correlated with glands' dose volume histograms. Subjective xerostomia questionnaires have been developed and validated. The pattern of local-regional recurrences has been examined using CT scans at the time of recurrence, transferring the recurrence volumes to the planning CT scans and regenerating the dose distributions at the recurrence sites. Target coverage and dose homogeneity in IMRT treatment plans were found to be significantly better than standard RT plans. Significant parotid gland sparing was achieved. The relationships among dose, irradiated volume and saliva flow rates from the parotid glands were characterized by dose and volume thresholds. A mean dose of 26 Gy was found to be the threshold for stimulated saliva. Subjective xerostomia was significantly reduced in patients irradiated with parotid sparing techniques, compared to patients with similar tumors treated with standard RT. The large majority of recurrences occurred inside high-risk targets. Tangible gains in salivary gland sparing and target coverage are being achieved and an improvement in some measures of quality of life is suggested by our findings. A mean parotid gland dose of < or = 26 Gy should be a planning objective if significant parotid function preservation is desired. The pattern of recurrence suggests that careful escalation of the dose to targets judged to be at highest risk may improve tumor control.
Increasing the structural coverage of tuberculosis drug targets
Baugh, Loren; Phan, Isabelle; Begley, Darren W.; ...
2014-12-19
High-resolution three-dimensional structures of essential Mycobacterium tuberculosis (Mtb) proteins provide templates for TB drug design, but are available for only a small fraction of the Mtb proteome. Here we evaluate an intra-genus “homolog-rescue” strategy to increase the structural information available for TB drug discovery by using mycobacterial homologs with conserved active sites. We found that of 179 potential TB drug targets selected for x-ray structure determination, only 16 yielded a crystal structure. By adding 1675 homologs from nine other mycobacterial species to the pipeline, structures representing an additional 52 otherwise intractable targets were solved. To determine whether these homolog structuresmore » would be useful surrogates in TB drug design, we compared the active sites of 106 pairs of Mtb and non-TB mycobacterial (NTM) enzyme homologs with experimentally determined structures, using three metrics of active site similarity, including superposition of continuous pharmacophoric property distributions. Pair-wise structural comparisons revealed that 19/22 pairs with >55% overall sequence identity had active site Cα RMSD <1 Å, >85% side chain identity, and ≥80% PS APF (similarity based on pharmacophoric properties) indicating highly conserved active site shape and chemistry. Applying these results to the 52 NTM structures described above, 41 shared >55% sequence identity with the Mtb target, thus increasing the effective structural coverage of the 179 Mtb targets over three-fold (from 9% to 32%). The utility of these structures in TB drug design can be tested by designing inhibitors using the homolog structure and assaying the cognate Mtb enzyme; a promising test case, Mtb cytidylate kinase, is described. The homolog-rescue strategy evaluated here for TB is also generalizable to drug targets for other diseases.« less
Increasing the Structural Coverage of Tuberculosis Drug Targets
Baugh, Loren; Phan, Isabelle; Begley, Darren W.; Clifton, Matthew C.; Armour, Brianna; Dranow, David M.; Taylor, Brandy M.; Muruthi, Marvin M.; Abendroth, Jan; Fairman, James W.; Fox, David; Dieterich, Shellie H.; Staker, Bart L.; Gardberg, Anna S.; Choi, Ryan; Hewitt, Stephen N.; Napuli, Alberto J.; Myers, Janette; Barrett, Lynn K.; Zhang, Yang; Ferrell, Micah; Mundt, Elizabeth; Thompkins, Katie; Tran, Ngoc; Lyons-Abbott, Sally; Abramov, Ariel; Sekar, Aarthi; Serbzhinskiy, Dmitri; Lorimer, Don; Buchko, Garry W.; Stacy, Robin; Stewart, Lance J.; Edwards, Thomas E.; Van Voorhis, Wesley C.; Myler, Peter J.
2015-01-01
High-resolution three-dimensional structures of essential Mycobacterium tuberculosis (Mtb) proteins provide templates for TB drug design, but are available for only a small fraction of the Mtb proteome. Here we evaluate an intra-genus “homolog-rescue” strategy to increase the structural information available for TB drug discovery by using mycobacterial homologs with conserved active sites. Of 179 potential TB drug targets selected for x-ray structure determination, only 16 yielded a crystal structure. By adding 1675 homologs from nine other mycobacterial species to the pipeline, structures representing an additional 52 otherwise intractable targets were solved. To determine whether these homolog structures would be useful surrogates in TB drug design, we compared the active sites of 106 pairs of Mtb and non-TB mycobacterial (NTM) enzyme homologs with experimentally determined structures, using three metrics of active site similarity, including superposition of continuous pharmacophoric property distributions. Pair-wise structural comparisons revealed that 19/22 pairs with >55% overall sequence identity had active site Cα RMSD <1Å, >85% side chain identity, and ≥80% PSAPF (similarity based on pharmacophoric properties) indicating highly conserved active site shape and chemistry. Applying these results to the 52 NTM structures described above, 41 shared >55% sequence identity with the Mtb target, thus increasing the effective structural coverage of the 179 Mtb targets over three-fold (from 9% to 32%). The utility of these structures in TB drug design can be tested by designing inhibitors using the homolog structure and assaying the cognate Mtb enzyme; a promising test case, Mtb cytidylate kinase, is described. The homolog-rescue strategy evaluated here for TB is also generalizable to drug targets for other diseases. PMID:25613812
SU-E-T-124: Dosimetric Comparison of HDR Brachytherapy and Intensity Modulated Proton Therapy
DOE Office of Scientific and Technical Information (OSTI.GOV)
Wu, J; Wu, H; Das, I
2014-06-01
Purpose: Brachytherapy is known to be able to deliver more radiation dose to tumor while minimizing radiation dose to surrounding normal tissues. Proton therapy also provides superior dose distribution due to Bragg peak. Since both HDR and Intensity Modulated Proton Therapy (IMPT) are beneficial for their quick dose drop off, our goal in this study is to compare the pace of dose gradient drop-off between HDR and IMPT plans based on the same CT image data-set. In addition, normal tissues sparing were also compared among HDR, IMPT and SBRT. Methods: Five cervical cancer cases treated with EBRT + HDR boostmore » combination with Tandem and Ovoid applicator were used for comparison purpose. Original HDR plans with prescribed dose of 5.5 Gy x 5 fractions were generated and optimized. The 100% isodose line of HDR plans was converted to a dose volume, and treated as CTV for IMPT and SBRT planning. The same HDR CT scans were also used for IMPT plan and SBRT plan for direct comparison. The philosophy of the IMPT and SBRT planning was to create the same CTV coverage as HDR plans. All three modalities treatment plans were compared to each other with a set of predetermined criteria. Results: With similar target volume coverage in cervix cancer boost treatment, HDR provides a slightly sharper dose drop-off from 100% to 50% isodose line, averagely in all directions compared to IMPT. However, IMPT demonstrated more dose gradient drop-off at the junction of the target and normal tissues by providing more normal tissue sparing and superior capability to reduce integral dose. Conclusion: IMPT is capable of providing comparable dose drop-off as HDR. IMPT can be explored as replacement for HDR brachytherapy in various applications.« less
WE-AB-209-08: Novel Beam-Specific Adaptive Margins for Reducing Organ-At-Risk Doses
DOE Office of Scientific and Technical Information (OSTI.GOV)
Tsang, H; Kamerling, CP; Ziegenhein, P
2016-06-15
Purpose: Current practice of using 3D margins in radiotherapy with high-energy photon beams provides larger-than-required target coverage. According to the photon depth-dose curve, target displacements in beam direction result in minute changes in dose delivered. We exploit this behavior by generating margins on a per-beam basis which simultaneously account for the relative distance of the target and adjacent organs-at-risk (OARs). Methods: For each beam, we consider only geometrical uncertainties of the target location perpendicular to beam direction. By weighting voxels based on its proximity to an OAR, we generate adaptive margins that yield similar overall target coverage probability and reducedmore » OAR dose-burden, at the expense of increased target volume. Three IMRT plans, using 3D margins and 2D per-beam margins with and without adaptation, were generated for five prostate patients with a prescription dose Dpres of 78Gy in 2Gy fractions using identical optimisation constraints. Systematic uncertainties of 1.1, 1.1, 1.5mm in the LR, SI, and AP directions, respectively, and 0.9, 1.1, 1.0mm for the random uncertainties, were assumed. A verification tool was employed to simulate the effects of systematic and random errors using a population size of 50,000. The fraction of the population that satisfies or violates a given DVH constraint was used for comparison. Results: We observe similar target coverage across all plans, with at least 97.5% of the population meeting the D98%>95%Dpres constraint. When looking at the probability of the population receiving D5<70Gy for the rectum, we observed median absolute increases of 23.61% (range, 2.15%–27.85%) and 6.97% (range, 0.65%–17.76%) using per-beam margins with and without adaptation, respectively, relative to using 3D margins. Conclusion: We observed sufficient and similar target coverage using per-beam margins. By adapting each per-beam margin away from an OAR, we can further reduce OAR dose without significantly lowering target coverage probability by irradiating more less-important tissues. This work is supported by Cancer Research UK under Programme C33589/A19908. Research at ICR is also supported by Cancer Research UK under Programme C33589/A19727 and NHS funding to the NIHR Biomedical Research Centre at RMH and ICR.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Ma, C; Yin, Y
Purpose: To compare the dosimetric difference of the target volume and organs at risk(OARs) between conventional intensity-modulated radiotherapy(C-IMRT) and knowledge-based radiation therapy (KBRT) plans for cervix cancer. Methods: 39 patients with cervical cancer after surgery were randomly selected, 20 patient plans were used to create the model, the other 19 cases used for comparative evaluation. All plans were designed in Eclipse system. The prescription dose was 30.6Gy, 17 fractions, OARs dose satisfied to the clinical requirement. A paired t test was used to evaluate the differences of dose-volume histograms (DVH). Results: Comparaed to C-IMRT plan, the KBRT plan target canmore » achieve the similar target dose coverage, D98,D95,D2,HI and CI had no difference (P≥0.05). The dose of rectum, bladder and femoral heads had no significant differences(P≥0.05). The time was used to design treatment plan was significant reduced. Conclusion: This study shows that postoperative radiotherapy of cervical KBRT plans can achieve the similar target and OARs dose, but the shorter designing time.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Quirk, S; Conroy, L; Smith, WL
Partial breast irradiation (PBI) following breast-conserving surgery is emerging as an effective means to achieve local control and reduce irradiated breast volume. Patients are planned on a static CT image; however, treatment is delivered while the patient is free-breathing. Respiratory motion can degrade plan quality by reducing target coverage and/or dose homogeneity. A variety of methods can be used to determine the required margin for respiratory motion in PBI. We derive geometric and dosimetric respiratory 1D margin. We also verify the adequacy of the typical 5 mm respiratory margin in 3D by evaluating plan quality for increasing respiratory amplitudes (2–20more » mm). Ten PBI plans were used for dosimetric evaluation. A database of volunteer respiratory data, with similar characteristics to breast cancer patients, was used for this study. We derived a geometric 95%-margin of 3 mm from the population respiratory data. We derived a dosimetric 95%-margin of 2 mm by convolving 1D dose profiles with respiratory probability density functions. The 5 mm respiratory margin is possibly too large when 1D coverage is assessed and could lead to unnecessary normal tissue irradiation. Assessing margins only for coverage may be insufficient; 3D dosimetric assessment revealed degradation in dose homogeneity is the limiting factor, not target coverage. Hotspots increased even for the smallest respiratory amplitudes, while target coverage only degraded at amplitudes greater than 10 mm. The 5 mm respiratory margin is adequate for coverage, but due to plan quality degradation, respiratory management is recommended for patients with respiratory amplitudes greater than 10 mm.« less
Jia, Pengfei; Xu, Jun; Zhou, Xiaoxi; Chen, Jian; Tang, Lemin
2017-12-01
The aim of this study is to compare the planning quality and delivery efficiency between dynamic intensity modulated radiation therapy (d-IMRT) and dual arc volumetric modulated arc therapy (VMAT) systematically for nasopharyngeal carcinoma (NPC) patients with multi-prescribed dose levels, and to analyze the correlations between target volumes and plan qualities. A total of 20 patients of NPC with 4-5 prescribed dose levels to achieve simultaneous integrated boost (SIB) treated by sliding window d-IMRT in our department from 2014 to 2015 were re-planned with dual arc VMAT. All optimization objectives for each VMAT plan were as the same as the corresponding d-IMRT plan. The dose parameters for targets and organ at risk (OAR), the delivery time and monitor units (MU) in two sets of plans were compared respectively. The treatment accuracy was tested by three dimensional dose validation system. Finally, the correlations between the difference of planning quality and the volume of targets were discussed. The conform indexes (CIs) of planning target volumes (PTVs) in VMAT plans were obviously high than those in d-IMRT plans ( P < 0.05), but no significant correlations between the difference of CIs and the volume of targets were discovered ( P > 0.05). The target coverage and heterogeneity indexes (HIs) of PTV 1 and PGTV nd and PTV 3 in two sets of plans were consistent. The doses of PTV 2 decreased and HIs were worse in VMAT plans. VMAT could provide better spinal cord and brainstem sparing, but increase mean dose of parotids. The average number of MUs and delivery time for d-IMRT were 3.32 and 2.19 times of that for VMAT. The γ-index (3 mm, 3%) analysis for each plans was more than 97% in COMPASS ® measurement for quality assurance (QA). The results show that target dose coverages in d-IMRT and VMAT plans are similar for NPC with multi-prescribed dose levels. VMAT could improve the the CIs of targets, but reduce the dose to the target volume in neck except for PGTV nd . The biggest advantages of VMAT over d-IMRT are delivery efficiency and QA.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Kumaran Nair, C; Hoffman, D; Wright, C
Purpose: We aim to evaluate a new commercial dose mimicking inverse-planning application that was designed to provide cross-platform treatment planning, for its dosimetric quality and efficiency. The clinical benefit of this application allows patients treated on O-shaped linac to receive an equivalent plan on conventional L-shaped linac as needed for workflow or machine downtime. Methods: The dose mimicking optimization process seeks to create a similar DVH of an O-shaped linac-based plans with an alternative treatment technique (IMRT or VMAT), by maintaining target conformity, and penalizing dose falloff outside the target. Ten head and neck (HN) helical delivery plans, including simplemore » and complex cases were selected for re-planning with the dose mimicking application. All plans were generated for a 6 MV beam model, using 7-field/ 9-field IMRT and VMAT techniques. PTV coverage (D1, D99 and homogeneity index [HI]), and OARs avoidance (Dmean / Dmax) were compared. Results: The resulting dose mimicked HN plans achieved acceptable PTV coverage for HI (VMAT 7.0±2.3, 7-fld 7.3±2.4, and 9-fld 7.0±2.4), D99 (98.0%±0.7%, 97.8%±0.7%, and 98.0%±0.7%), as well as D1 (106.4%±2.1%, 106.5%±2.2%, and 106.4%±2.1%), respectively. The OAR dose discrepancy varied: brainstem (2% to 4%), cord (3% to 6%), esophagus (−4% to −8%), larynx (−4% to 2%), and parotid (4% to 14%). Mimicked plans would typically be needed for 1–5 fractions of a treatment course, and we estimate <1% variance would be introduced in target coverage while maintaining comparable low dose to OARs. All mimicked plans were approved by independent physician and passed patient specific QA within our established tolerance. Conclusion: Dose mimicked plans provide a practical alternative for responding to clinical workflow issues, and provide reliability for patient treatment. The quality of dose mimicking for HN patients highly depends on the delivery technique, field numbers and angles, as well as user selection of structures.« less
Abraham, S; Fogliata, A; Jordaan, A; Clivio, A; Vanetti, E; Cozzi, L
2013-01-01
Objective: To evaluate the use of volumetric-modulated arc therapy [VMAT, RapidArc® (RA); Varian Medical Systems, Palo Alto, CA] for the treatment of cutaneous Kaposi’s sarcoma (KS) of lower extremities with adequate target coverage and high bone sparing, and to compare VMAT with electron beam therapy. Methods: 10 patients were planned with either RA or electron beams. The dose was prescribed to 30 Gy, 10 fractions, to mean the planning target volume (PTV), and significant maximum dose to bone was limited to 30 Gy. Plans were designed for 6-MV photon beams for RA and 6 MeV for electrons. Dose distributions were computed with AcurosXB® (Varian Medical Systems) for photons and with a Monte Carlo algorithm for electrons. Results: V90% was 97.3±1.2 for RA plans and 78.2±2.6 for electrons; similarly, V107% was 2.5±2.2 and 37.7±3.4, respectively. RA met coverage criteria. Concerning bone sparing, D2% was 29.6±1.1 for RA and 31.0±2.4 for electrons. Although acceptable for bone involvement, pronounced target coverage violations were obtained for electron plans. Monitor units were similar for electrons and RA, although for the latter they increased when superior bone sparing was imposed. Delivery times were 12.1±4.0 min for electrons and 4.8±1.3 min for the most modulated RA plans. Conclusion: High plan quality was shown for KS in the lower extremities using VMAT, and this might simplify their management in comparison with the more conventional usage of electrons, particularly in institutes with limited staff resources and heavy workloads. Advances in knowledge: VMAT is also dosimetrically extremely advantageous in a typology of treatments where electron beam therapy is mainly considered to be effective owing to the limited penetration of the beams. PMID:23392192
Gerlier, Laetitia; Lamotte, Mark; Dos Santos Mendes, Sofia; Damm, Oliver; Schwehm, Markus; Eichner, Martin
2016-08-01
Our objectives were to estimate the public health outcomes of vaccinating Belgian children using an intranasal tetravalent live-attenuated influenza vaccine (QLAIV) combined with current coverage of high-risk/elderly individuals using the trivalent inactivated vaccine. We used a deterministic, age-structured, dynamic model to simulate seasonal influenza transmission in the Belgian population under the current coverage or after extending vaccination with QLAIV to healthy children aged 2-17 years. Differential equations describe demographic changes, exposure to infectious individuals, infection recovery, and immunity dynamics. The basic reproduction number (R 0) was calibrated to the observed number of influenza doctor visits/year. Vaccine efficacy was 80 % (live-attenuated) and 59-68 % (inactivated). The 10-year incidence of symptomatic influenza was calculated with different coverage scenarios (add-on to current coverage). Model calibration yielded R 0 = 1.1. QLAIV coverage of 75 % of those aged 2-17 years averted 374,000 symptomatic cases/year (57 % of the current number), 244,000 of which were among adults (indirect effect). Vaccinating 75 % of those aged 2-11 years and 50 % of those aged 12-17 years averted 333,200 cases/year (213,000 adult cases/year). Vaccinating only healthy children aged 2-5 years generated direct protection but limited indirect protection, even with 90 % coverage (40,800 averted adult cases/year; -8.4 %). Targeting all children averted twice as many high-risk cases as targeting high-risk children only (8485 vs. 4965/year with 75 % coverage). Sensitivity analyses showed the robustness of results. The model highlights the direct and indirect protection benefits when vaccinating healthy children with QLAIV in Belgium. Policies targeting only high-risk individuals or the youngest provide limited herd protection, as school-age children are important influenza vectors in the community.
The web and public confidence in MMR vaccination in Italy.
Aquino, Francesco; Donzelli, Gabriele; De Franco, Emanuela; Privitera, Gaetano; Lopalco, Pier Luigi; Carducci, Annalaura
2017-08-16
Measles, mumps and rubella (MMR) vaccination coverage in Italy has been decreasing starting from 2012 and, at the present, none of the Italian regions has achieved the goal of 95% coverage target. A decision of the Court of Justice of Rimini in March 2012 that awarded vaccine-injury compensation for a case of autism has been indicated as a probable trigger event leading to a reduction of vaccine confidence in Italy. The aim of the study was to explore the relationship between MMR vaccination coverage to online search trends and social network activity on the topic "autism and MMR vaccine", during the period 2010-2015. A significant inverse correlation was found between MMR vaccination coverage and Internet search activity, tweets and Facebook posts. New media might have played a role in spreading misinformation. Media monitoring could be useful to assess the level of vaccine hesitancy and to plan and target effective information campaigns. Copyright © 2017 Elsevier Ltd. All rights reserved.
Cesar, Juraci A; Sutil, Andréa T; Santos, Gabriela B dos; Cunha, Carolina F; Mendoza-Sassi, Raúl A
2012-11-01
This study aimed to evaluate public and private prenatal care for women in Rio Grande, Rio Grande do Sul State, Brazil. Women who gave birth at the two local maternity hospitals from January 1 to December 31, 2010, answered a standardized questionnaire. The interview sites in the public sector were primary health care units with and without the Family Health Strategy (FHS) and outpatient clinics; the private sector included clinics operated by health plans and private physicians' offices. The chi-square test was used to compare proportions. The response rate was 97.2% (2,395 out of 2,464). Among the 23 target variables and indicators, seven showed a clear advantage for mothers who had received prenatal care under the FHS and six for health plan clinics and private offices. Four variables showed virtually universal coverage at all five study sites. Prenatal care showed better coverage for pregnant women treated in the private sector. Pregnant women treated under the FHS showed similar coverage to that in the private sector.
Surveillance of Vaccination Coverage among Adult Populations - United States, 2015.
Williams, Walter W; Lu, Peng-Jun; O'Halloran, Alissa; Kim, David K; Grohskopf, Lisa A; Pilishvili, Tamara; Skoff, Tami H; Nelson, Noele P; Harpaz, Rafael; Markowitz, Lauri E; Rodriguez-Lainz, Alfonso; Fiebelkorn, Amy Parker
2017-05-05
Overall, the prevalence of illness attributable to vaccine-preventable diseases is greater among adults than among children. Adults are recommended to receive vaccinations based on their age, underlying medical conditions, lifestyle, prior vaccinations, and other considerations. Updated vaccination recommendations from CDC are published annually in the U.S. Adult Immunization Schedule. Despite longstanding recommendations for use of many vaccines, vaccination coverage among U.S. adults is low. August 2014-June 2015 (for influenza vaccination) and January-December 2015 (for pneumococcal, tetanus and diphtheria [Td] and tetanus and diphtheria with acellular pertussis [Tdap], hepatitis A, hepatitis B, herpes zoster, and human papillomavirus [HPV] vaccination). The National Health Interview Survey (NHIS) is a continuous, cross-sectional national household survey of the noninstitutionalized U.S. civilian population. In-person interviews are conducted throughout the year in a probability sample of households, and NHIS data are compiled and released annually. The survey objective is to monitor the health of the U.S. population and provide estimates of health indicators, health care use and access, and health-related behaviors. Compared with data from the 2014 NHIS, increases in vaccination coverage occurred for influenza vaccine among adults aged ≥19 years (a 1.6 percentage point increase compared with the 2013-14 season to 44.8%), pneumococcal vaccine among adults aged 19-64 years at increased risk for pneumococcal disease (a 2.8 percentage point increase to 23.0%), Tdap vaccine among adults aged ≥19 years and adults aged 19-64 years (a 3.1 percentage point and 3.3 percentage point increase to 23.1% and to 24.7%, respectively), herpes zoster vaccine among adults aged ≥60 years and adults aged ≥65 years (a 2.7 percentage point and 3.2 percentage point increase to 30.6% and to 34.2%, respectively), and hepatitis B vaccine among health care personnel (HCP) aged ≥19 years (a 4.1 percentage point increase to 64.7%). Herpes zoster vaccination coverage in 2015 met the Healthy People 2020 target of 30%. Aside from these modest improvements, vaccination coverage among adults in 2015 was similar to estimates from 2014. Racial/ethnic differences in coverage persisted for all seven vaccines, with higher coverage generally for whites compared with most other groups. Adults without health insurance reported receipt of influenza vaccine (all age groups), pneumococcal vaccine (adults aged 19-64 years at increased risk), Td vaccine (adults aged ≥19 years, 19-64 years, and 50-64 years), Tdap vaccine (adults aged ≥19 years and 19-64 years), hepatitis A vaccine (adults aged ≥19 years overall and among travelers), hepatitis B vaccine (adults aged ≥19 years, 19-49 years, and among travelers), herpes zoster vaccine (adults aged ≥60 years), and HPV vaccine (males and females aged 19-26 years) less often than those with health insurance. Adults who reported having a usual place for health care generally reported receipt of recommended vaccinations more often than those who did not have such a place, regardless of whether they had health insurance. Vaccination coverage was higher among adults reporting one or more physician contacts in the past year compared with those who had not visited a physician in the past year, regardless of whether they had health insurance. Even among adults who had health insurance and ≥10 physician contacts within the past year, depending on the vaccine, 18.2%-85.6% reported not having received vaccinations that were recommended either for all persons or for those with specific indications. Overall, vaccination coverage among U.S.-born adults was higher than that among foreign-born adults, with few exceptions (influenza vaccination [adults aged 19-49 years and 50-64 years], hepatitis A vaccination [adults aged ≥19 years], and hepatitis B vaccination [adults aged ≥19 years with diabetes or chronic liver conditions]). Coverage for all vaccines for adults remained low but modest gains occurred in vaccination coverage for influenza (adults aged ≥19 years), pneumococcal (adults aged 19-64 years with increased risk), Tdap (adults aged ≥19 years and adults aged 19-64 years), herpes zoster (adults aged ≥60 years and ≥65 years), and hepatitis B (HCP aged ≥19 years); coverage for other vaccines and groups with vaccination indications did not improve. The 30% Healthy People 2020 target for herpes zoster vaccination was met. Racial/ethnic disparities persisted for routinely recommended adult vaccines. Missed opportunities to vaccinate remained. Although having health insurance coverage and a usual place for health care were associated with higher vaccination coverage, these factors alone were not associated with optimal adult vaccination coverage. HPV vaccination coverage for males and females has increased since CDC recommended vaccination to prevent cancers caused by HPV, but many adolescents and young adults remained unvaccinated. Assessing factors associated with low coverage rates and disparities in vaccination is important for implementing strategies to improve vaccination coverage. Evidence-based practices that have been demonstrated to improve vaccination coverage should be used. These practices include assessment of patients' vaccination indications by health care providers and routine recommendation and offer of needed vaccines to adults, implementation of reminder-recall systems, use of standing-order programs for vaccination, and assessment of practice-level vaccination rates with feedback to staff members. For vaccination coverage to be improved among those who reported lower coverage rates of recommended adult vaccines, efforts also are needed to identify adults who do not have a regular provider or insurance and who report fewer health care visits.
Surveillance of Vaccination Coverage among Adult Populations — United States, 2015
Lu, Peng-Jun; O’Halloran, Alissa; Kim, David K.; Grohskopf, Lisa A.; Pilishvili, Tamara; Skoff, Tami H.; Nelson, Noele P.; Harpaz, Rafael; Markowitz, Lauri E.; Rodriguez-Lainz, Alfonso; Fiebelkorn, Amy Parker
2017-01-01
Problem/Condition Overall, the prevalence of illness attributable to vaccine-preventable diseases is greater among adults than among children. Adults are recommended to receive vaccinations based on their age, underlying medical conditions, lifestyle, prior vaccinations, and other considerations. Updated vaccination recommendations from CDC are published annually in the U.S. Adult Immunization Schedule. Despite longstanding recommendations for use of many vaccines, vaccination coverage among U.S. adults is low. Period Covered August 2014–June 2015 (for influenza vaccination) and January–December 2015 (for pneumococcal, tetanus and diphtheria [Td] and tetanus and diphtheria with acellular pertussis [Tdap], hepatitis A, hepatitis B, herpes zoster, and human papillomavirus [HPV] vaccination). Description of System The National Health Interview Survey (NHIS) is a continuous, cross-sectional national household survey of the noninstitutionalized U.S. civilian population. In-person interviews are conducted throughout the year in a probability sample of households, and NHIS data are compiled and released annually. The survey objective is to monitor the health of the U.S. population and provide estimates of health indicators, health care use and access, and health-related behaviors. Results Compared with data from the 2014 NHIS, increases in vaccination coverage occurred for influenza vaccine among adults aged ≥19 years (a 1.6 percentage point increase compared with the 2013–14 season to 44.8%), pneumococcal vaccine among adults aged 19–64 years at increased risk for pneumococcal disease (a 2.8 percentage point increase to 23.0%), Tdap vaccine among adults aged ≥19 years and adults aged 19–64 years (a 3.1 percentage point and 3.3 percentage point increase to 23.1% and to 24.7%, respectively), herpes zoster vaccine among adults aged ≥60 years and adults aged ≥65 years (a 2.7 percentage point and 3.2 percentage point increase to 30.6% and to 34.2%, respectively), and hepatitis B vaccine among health care personnel (HCP) aged ≥19 years (a 4.1 percentage point increase to 64.7%). Herpes zoster vaccination coverage in 2015 met the Healthy People 2020 target of 30%. Aside from these modest improvements, vaccination coverage among adults in 2015 was similar to estimates from 2014. Racial/ethnic differences in coverage persisted for all seven vaccines, with higher coverage generally for whites compared with most other groups. Adults without health insurance reported receipt of influenza vaccine (all age groups), pneumococcal vaccine (adults aged 19–64 years at increased risk), Td vaccine (adults aged ≥19 years, 19–64 years, and 50–64 years), Tdap vaccine (adults aged ≥19 years and 19–64 years), hepatitis A vaccine (adults aged ≥19 years overall and among travelers), hepatitis B vaccine (adults aged ≥19 years, 19–49 years, and among travelers), herpes zoster vaccine (adults aged ≥60 years), and HPV vaccine (males and females aged 19–26 years) less often than those with health insurance. Adults who reported having a usual place for health care generally reported receipt of recommended vaccinations more often than those who did not have such a place, regardless of whether they had health insurance. Vaccination coverage was higher among adults reporting one or more physician contacts in the past year compared with those who had not visited a physician in the past year, regardless of whether they had health insurance. Even among adults who had health insurance and ≥10 physician contacts within the past year, depending on the vaccine, 18.2%–85.6% reported not having received vaccinations that were recommended either for all persons or for those with specific indications. Overall, vaccination coverage among U.S.-born adults was higher than that among foreign-born adults, with few exceptions (influenza vaccination [adults aged 19–49 years and 50–64 years], hepatitis A vaccination [adults aged ≥19 years], and hepatitis B vaccination [adults aged ≥19 years with diabetes or chronic liver conditions]). Interpretation Coverage for all vaccines for adults remained low but modest gains occurred in vaccination coverage for influenza (adults aged ≥19 years), pneumococcal (adults aged 19–64 years with increased risk), Tdap (adults aged ≥19 years and adults aged 19–64 years), herpes zoster (adults aged ≥60 years and ≥65 years), and hepatitis B (HCP aged ≥19 years); coverage for other vaccines and groups with vaccination indications did not improve. The 30% Healthy People 2020 target for herpes zoster vaccination was met. Racial/ethnic disparities persisted for routinely recommended adult vaccines. Missed opportunities to vaccinate remained. Although having health insurance coverage and a usual place for health care were associated with higher vaccination coverage, these factors alone were not associated with optimal adult vaccination coverage. HPV vaccination coverage for males and females has increased since CDC recommended vaccination to prevent cancers caused by HPV, but many adolescents and young adults remained unvaccinated. Public Health Actions Assessing factors associated with low coverage rates and disparities in vaccination is important for implementing strategies to improve vaccination coverage. Evidence-based practices that have been demonstrated to improve vaccination coverage should be used. These practices include assessment of patients’ vaccination indications by health care providers and routine recommendation and offer of needed vaccines to adults, implementation of reminder-recall systems, use of standing-order programs for vaccination, and assessment of practice-level vaccination rates with feedback to staff members. For vaccination coverage to be improved among those who reported lower coverage rates of recommended adult vaccines, efforts also are needed to identify adults who do not have a regular provider or insurance and who report fewer health care visits. PMID:28472027
DOE Office of Scientific and Technical Information (OSTI.GOV)
Meyer, Jeff, E-mail: jmeye3@utsouthwestern.ed; Bluett, Jaques; Amos, Richard
Purpose: Conventional proton therapy with passively scattered beams is used to treat a number of tumor sites, including prostate cancer. Spot scanning proton therapy is a treatment delivery means that improves conformal coverage of the clinical target volume (CTV). Placement of individual spots within a target is dependent on traversed tissue density. Errors in patient alignment perturb dose distributions. Moreover, there is a need for a rational planning approach that can mitigate the dosimetric effect of random alignment errors. We propose a treatment planning approach and then analyze the consequences of various simulated alignment errors on prostate treatments. Methods andmore » Materials: Ten control patients with localized prostate cancer underwent treatment planning for spot scanning proton therapy. After delineation of the clinical target volume, a scanning target volume (STV) was created to guide dose coverage. Errors in patient alignment in two axes (rotational and yaw) as well as translational errors in the anteroposterior direction were then simulated, and dose to the CTV and normal tissues were reanalyzed. Results: Coverage of the CTV remained high even in the setting of extreme rotational and yaw misalignments. Changes in the rectum and bladder V45 and V70 were similarly minimal, except in the case of translational errors, where, as a result of opposed lateral beam arrangements, much larger dosimetric perturbations were observed. Conclusions: The concept of the STV as applied to spot scanning radiation therapy and as presented in this report leads to robust coverage of the CTV even in the setting of extreme patient misalignments.« less
Osei, Ernest; Barnett, Rob
2015-01-01
The aim of this study is to provide guidelines for the selection of external‐beam radiation therapy target margins to compensate for target motion in the lung during treatment planning. A convolution model was employed to predict the effect of target motion on the delivered dose distribution. The accuracy of the model was confirmed with radiochromic film measurements in both static and dynamic phantom modes. 502 unique patient breathing traces were recorded and used to simulate the effect of target motion on a dose distribution. A 1D probability density function (PDF) representing the position of the target throughout the breathing cycle was generated from each breathing trace obtained during 4D CT. Changes in the target D95 (the minimum dose received by 95% of the treatment target) due to target motion were analyzed and shown to correlate with the standard deviation of the PDF. Furthermore, the amount of target D95 recovered per millimeter of increased field width was also shown to correlate with the standard deviation of the PDF. The sensitivity of changes in dose coverage with respect to target size was also determined. Margin selection recommendations that can be used to compensate for loss of target D95 were generated based on the simulation results. These results are discussed in the context of clinical plans. We conclude that, for PDF standard deviations less than 0.4 cm with target sizes greater than 5 cm, little or no additional margins are required. Targets which are smaller than 5 cm with PDF standard deviations larger than 0.4 cm are most susceptible to loss of coverage. The largest additional required margin in this study was determined to be 8 mm. PACS numbers: 87.53.Bn, 87.53.Kn, 87.55.D‐, 87.55.Gh
DOE Office of Scientific and Technical Information (OSTI.GOV)
Gorayski, Peter; Fitzgerald, Rhys; Barry, Tamara
Cutaneous squamous cell carcinoma with large nerve perineural (LNPN) infiltration of the base of skull is a radiotherapeutic challenge given the complex target volumes to nearby organs at risk (OAR). A comparative planning study was undertaken to evaluate dosimetric differences between volumetric modulated arc therapy (VMAT) versus intensity modulated radiation therapy (IMRT) in the treatment of LNPN. Five consecutive patients previously treated with IMRT for LNPN were selected. VMAT plans were generated for each case using the same planning target volumes (PTV), dose prescriptions and OAR constraints as IMRT. Comparative parameters used to assess target volume coverage, conformity and homogeneitymore » included V95 of the PTV (volume encompassed by the 95% isodose), conformity index (CI) and homogeneity index (HI). In addition, OAR maximum point doses, V20, V30, non-target tissue (NTT) point max doses, NTT volume above reference dose, monitor units (MU) were compared. IMRT and VMAT plans generated were comparable for CI (P = 0.12) and HI (P = 0.89). VMAT plans achieved better V95 (P = < 0.001) and reduced V20 and V30 by 652 cubic centimetres (cc) (28.5%) and 425.7 cc (29.1%), respectively. VMAT increased MU delivered by 18% without a corresponding increase in NTT dose. Compared with IMRT plans for LNPN, VMAT achieved comparable HI and CI.« less
Seasonal influenza vaccine coverage among high-risk populations in Thailand, 2010-2012.
Owusu, Jocelynn T; Prapasiri, Prabda; Ditsungnoen, Darunee; Leetongin, Grit; Yoocharoen, Pornsak; Rattanayot, Jarowee; Olsen, Sonja J; Muangchana, Charung
2015-01-29
The Advisory Committee on Immunization Practice of Thailand prioritizes seasonal influenza vaccinations for populations who are at highest risk for serious complications (pregnant women, children 6 months-2 years, persons ≥65 years, persons with chronic diseases, obese persons), and healthcare personnel and poultry cullers. The Thailand government purchases seasonal influenza vaccine for these groups. We assessed vaccination coverage among high-risk groups in Thailand from 2010 to 2012. National records on persons who received publicly purchased vaccines from 2010 to 2012 were analyzed by high-risk category. Denominator data from multiple sources were compared to calculate coverage. Vaccine coverage was defined as the proportion of individuals in each category who received the vaccine. Vaccine wastage was defined as the proportion of publicly purchased vaccines that were not used. From 2010 to 2012, 8.18 million influenza vaccines were publicly purchased (range, 2.37-3.29 million doses/year), and vaccine purchases increased 39% over these years. Vaccine wastage was 9.5%. Approximately 5.7 million (77%) vaccine doses were administered to persons ≥65 years and persons with chronic diseases, 1.4 million (19%) to healthcare personnel/poultry cullers, 82,570 (1.1%) to children 6 months-2 years, 78,885 (1.1%) to obese persons, 26,481 (0.4%) to mentally disabled persons, and 17,787 (0.2%) to pregnant women. Between 2010 and 2012, coverage increased among persons with chronic diseases (8.6% versus 14%; p<0.01) and persons ≥65 years (12%, versus 20%; p<0.01); however, coverage decreased for mentally disabled persons (6.1% versus 4.9%; p<0.01), children 6 months-2 years (2.3% versus 0.9%; p<0.01), pregnant women (1.1% versus 0.9%; p<0.01), and obese persons (0.2% versus 0.1%; p<0.01). From 2010 to 2012, the availability of publicly purchased vaccines increased. While coverage remained low for all target groups, coverage was highest among persons ≥65 years and persons with chronic diseases. Annual coverage assessments are necessary to promote higher coverage among high-risk groups in Thailand. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.
Seasonal influenza vaccine coverage among high-risk populations in Thailand, 2010–2012
Owusu, Jocelynn T.; Prapasiri, Prabda; Ditsungnoen, Darunee; Leetongin, Grit; Yoocharoen, Pornsak; Rattanayot, Jarowee; Olsen, Sonja J.; Muangchana, Charung
2015-01-01
Background The Advisory Committee on Immunization Practice of Thailand prioritizes seasonal influenza vaccinations for populations who are at highest risk for serious complications (pregnant women, children 6 months–2 years, persons ≥65 years, persons with chronic diseases, obese persons), and health-care personnel and poultry cullers. The Thailand government purchases seasonal influenza vaccine for these groups. We assessed vaccination coverage among high-risk groups in Thailand from 2010 to 2012. Methods National records on persons who received publicly purchased vaccines from 2010 to 2012 were analyzed by high-risk category. Denominator data from multiple sources were compared to calculate coverage. Vaccine coverage was defined as the proportion of individuals in each category who received the vaccine. Vaccine wastage was defined as the proportion of publicly purchased vaccines that were not used. Results From 2010 to 2012, 8.18 million influenza vaccines were publicly purchased (range, 2.37–3.29 million doses/year), and vaccine purchases increased 39% over these years. Vaccine wastage was 9.5%. Approximately 5.7 million (77%) vaccine doses were administered to persons ≥65 years and persons with chronic diseases, 1.4 million (19%) to healthcare personnel/poultry cullers, 82,570 (1.1%) to children 6 months–2 years, 78,885 (1.1%) to obese persons, 26,481 (0.4%) to mentally disabled persons, and 17,787 (0.2%) to pregnant women. Between 2010 and 2012, coverage increased among persons with chronic diseases (8.6% versus 14%; p < 0.01) and persons ≥65 years (12%, versus 20%; p < 0.01); however, coverage decreased for mentally disabled persons (6.1% versus 4.9%; p < 0.01), children 6 months–2 years (2.3% versus 0.9%; p < 0.01), pregnant women (1.1% versus 0.9%; p < 0.01), and obese persons (0.2% versus 0.1%; p < 0.01). Conclusions From 2010 to 2012, the availability of publicly purchased vaccines increased. While coverage remained low for all target groups, coverage was highest among persons ≥65 years and persons with chronic diseases. Annual coverage assessments are necessary to promote higher coverage among high-risk groups in Thailand. PMID:25454853
The 5As: A practical taxonomy for the determinants of vaccine uptake.
Thomson, Angus; Robinson, Karis; Vallée-Tourangeau, Gaëlle
2016-02-17
Suboptimal vaccine uptake in both childhood and adult immunisation programs limits their full potential impact on global health. A recent progress review of the Global Vaccine Action Plan stated that "countries should urgently identify barriers and bottlenecks and implement targeted approaches to increase and sustain coverage". However, vaccination coverage may be determined by a complex mix of demographic, structural, social and behavioral factors. To develop a practical taxonomy to organise the myriad possible root causes of a gap in vaccination coverage rates, we performed a narrative review of the literature and tested whether all non-socio-demographic determinants of coverage could be organised into 4 dimensions: Access, Affordability, Awareness and Acceptance. Forty-three studies were reviewed, from which we identified 23 primary determinants of vaccination uptake. We identified a fifth domain, Activation, which captured interventions such as SMS reminders which effectively nudge people towards getting vaccinated. The 5As taxonomy captured all identified determinants of vaccine uptake. This intuitive taxonomy has already facilitated mutual understanding of the primary determinants of suboptimal coverage within inter-sectorial working groups, a first step towards them developing targeted and effective solutions. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.
The Interplanetary Network Response to LIGO GW150914
NASA Technical Reports Server (NTRS)
Hurley, K.; Svinkin, D. S.; Aptekar, R.L.; Golenetskii, S. V.; Frederiks, D. D.; Boynton, W.; Mitrofanov, I. G.; Golovin, D. V.; Kozyrev, A. S.; Litvak, M. L.;
2016-01-01
We have performed a blind search for a gamma-ray transient of arbitrary duration and energy spectrum around the time of the LIGO gravitational-wave event GW150914 with the six-spacecraft interplanetary network (IPN). Four gamma-ray bursts were detected between 30 hr prior to the event and 6.1 hr after it, but none could convincingly be associated with GW150914. No other transients were detected down to limiting 15-150 keV fluences of roughly 5 x 10(exp -8) -5 x 10(exp -7) erg cm(exp -2). We discuss the search strategies and temporal coverage of the IPN on the day of the event and compare the spatial coverage to the region where GW150914 originated. We also report the negative result of a targeted search for the Fermi-GBM event reported in conjunction with GW150914.
de Figueiredo, Alexandre; Johnston, Iain G; Smith, David M D; Agarwal, Sumeet; Larson, Heidi J; Jones, Nick S
2016-10-01
Incomplete immunisation coverage causes preventable illness and death in both developing and developed countries. Identification of factors that might modulate coverage could inform effective immunisation programmes and policies. We constructed a performance indicator that could quantitatively approximate measures of the susceptibility of immunisation programmes to coverage losses, with an aim to identify correlations between trends in vaccine coverage and socioeconomic factors. We undertook a data-driven time-series analysis to examine trends in coverage of diphtheria, tetanus, and pertussis (DTP) vaccination across 190 countries over the past 30 years. We grouped countries into six world regions according to WHO classifications. We used Gaussian process regression to forecast future coverage rates and provide a vaccine performance index: a summary measure of the strength of immunisation coverage in a country. Overall vaccine coverage increased in all six world regions between 1980 and 2010, with variation in volatility and trends. Our vaccine performance index identified that 53 countries had more than a 50% chance of missing the Global Vaccine Action Plan (GVAP) target of 90% worldwide coverage with three doses of DTP (DTP3) by 2015. These countries were mostly in sub-Saharan Africa and south Asia, but Austria and Ukraine also featured. Factors associated with DTP3 immunisation coverage varied by world region: personal income (Spearman's ρ=0·66, p=0·0011) and government health spending (0·66, p<0·0001) were informative of immunisation coverage in the Eastern Mediterranean between 1980 and 2010, whereas primary school completion was informative of coverage in Africa (0·56, p<0·0001) over the same period. The proportion of births attended by skilled health staff correlated significantly with immunisation coverage across many world regions. Our vaccine performance index highlighted countries at risk of failing to achieve the GVAP target of 90% coverage by 2015, and could aid policy makers' assessments of the strength and resilience of immunisation programmes. Weakening correlations with socioeconomic factors show a need to tackle vaccine confidence, whereas strengthening correlations point to clear factors to address. UK Engineering and Physical Sciences Research Council. Copyright © 2016 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY license. Published by Elsevier Ltd.. All rights reserved.
Increasing Cervical Cancer Screening Coverage: A Randomised, Community-Based Clinical Trial.
Acera, Amelia; Manresa, Josep Maria; Rodriguez, Diego; Rodriguez, Ana; Bonet, Josep Maria; Trapero-Bertran, Marta; Hidalgo, Pablo; Sànchez, Norman; de Sanjosé, Silvia
2017-01-01
Opportunistic cervical cancer screening can lead to suboptimal screening coverage. Coverage could be increased after a personalised invitation to the target population. We present a community randomized intervention study with three strategies aiming to increase screening coverage. The CRICERVA study is a community-based clinical trial to improve coverage of population-based screening in the Cerdanyola SAP area in Barcelona.A total of 32,858 women residing in the study area, aged 30 to 70 years were evaluated. A total of 15,965 women were identified as having no registration of a cervical cytology in the last 3.5 years within the Public Health data base system. Eligible women were assigned to one of four community randomized intervention groups (IGs): (1) (IG1 N = 4197) personalised invitation letter, (2) (IG2 N = 3601) personalised invitation letter + informative leaflet, (3) (IG3 N = 6088) personalised invitation letter + informative leaflet + personalised phone call and (4) (Control N = 2079) based on spontaneous demand of cervical cancer screening as officially recommended. To evaluate screening coverage, we used heterogeneity tests to compare impact of the interventions and mixed logistic regression models to assess the age effect. We refer a "rescue" visit as the screening visit resulting from the study invitation. Among the 13,886 women in the IGs, 2,862 were evaluated as having an adequate screening history after the initial contact; 4,263 were lost to follow-up and 5,341 were identified as having insufficient screening and thus being eligible for a rescue visit. All intervention strategies significantly increased participation to screening compared to the control group. Coverage after the intervention reached 84.1% while the control group reached 64.8%. The final impact of our study was an increase of 20% in the three IGs and of 9% in the control group (p<0.001). Within the intervention arms, age was an important determinant of rescue visits showing a statistical interaction with the coverage attained in the IGs. Within the intervention groups, final screening coverage was significantly higher in IG3 (84.4%) (p<0.001). However, the differences were more substantial in the age groups 50-59 and those 60+. The highest impact of the IG3 intervention was observed among women 60+ y.o with 32.0% of them being rescued for screening. The lowest impact of the interventions was in younger women. The study confirms that using individual contact methods and assigning a fixed screening date notably increases participation in screening. The response to the invitation is strongly dependent on age. ClinicalTrials.gov NCT01373723.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Ma, L; Dong, P; Larson, D
Purpose: To investigate a new modulated beam orientation optimization (MBOO) approach maximizing treatment planning quality for the state-of-the-art flattening filter free (FFF) beam that has enabled rapid treatments of multiple brain targets. Methods: MBOO selects and optimizes a large number of intensity-modulated beams (400 or more) from all accessible beam angles surrounding a patient’s skull. The optimization algorithm was implemented on a standalone system that interfaced with the 3D Dicom images and structure sets. A standard published data set that consisted of 1 to 12 metastatic brain tumor combinations was selected for MBOO planning. The planning results from various coplanarmore » and non-coplanar configurations via MBOO were then compared with the results obtained from a clinical volume modulated arc therapy (VMAT) delivery system (Truebeam RapidArc, Varian Oncology). Results: When planning a few number of targets (n<4), MBOO produced results equivalent to non-coplanar multi-arc VMAT planning in terms of target volume coverage and normal tissue sparing. For example, the 12-Gy and 4-Gy normal brain volumes for the 3-target plans differed by less than 1 mL ( 3.0 mLvs 3.8 mL; and 35.2 mL vs 36.3 mL, respectively) for MBOO versus VMAT. However, when planning a larger number of targets (n≥4), MBOO significantly reduced the dose to the normal brain as compared to VMAT, though the target volume coverage was equivalent. For example, the 12-Gy and 4-Gy normal brain volumes for the 12-target plans were 10.8 mL vs. 18.0 mL and 217.9 mL vs. 390.0 mL, respectively for the non-coplanar MBOO versus the non-coplanar VMAT treatment plans, yielding a reduction in volume of more than 60% for the case. Conclusion: MBOO is a unique approach for maximizing normal tissue sparing when treating a large number (n≥4) of brain tumors with FFF linear accelerators. Dr Ma and Dr Sahgal are currently on the board of international society of stereotactic radiosurgery. Dr Sahgal has received support for educational presentations from Elekta company.« less
NASA Astrophysics Data System (ADS)
Anderle, Kristjan; Stroom, Joep; Vieira, Sandra; Pimentel, Nuno; Greco, Carlo; Durante, Marco; Graeff, Christian
2018-01-01
Intensity modulated particle therapy (IMPT) can produce highly conformal plans, but is limited in advanced lung cancer patients with multiple lesions due to motion and planning complexity. A 4D IMPT optimization including all motion states was expanded to include multiple targets, where each target (isocenter) is designated to specific field(s). Furthermore, to achieve stereotactic treatment planning objectives, target and OAR weights plus objective doses were automatically iteratively adapted. Finally, 4D doses were calculated for different motion scenarios. The results from our algorithm were compared to clinical stereotactic body radiation treatment (SBRT) plans. The study included eight patients with 24 lesions in total. Intended dose regimen for SBRT was 24 Gy in one fraction, but lower fractionated doses had to be delivered in three cases due to OAR constraints or failed plan quality assurance. The resulting IMPT treatment plans had no significant difference in target coverage compared to SBRT treatment plans. Average maximum point dose and dose to specific volume in OARs were on average 65% and 22% smaller with IMPT. IMPT could also deliver 24 Gy in one fraction in a patient where SBRT was limited due to the OAR vicinity. The developed algorithm shows the potential of IMPT in treatment of multiple moving targets in a complex geometry.
Spectroscopic and Photometric Properties of Carbon Stars in the Disk of the Andromeda Galaxy
NASA Astrophysics Data System (ADS)
Guhathakurta, Puragra; Toloba, E.; Guha, S.; Rushing, C.; Dorman, C.; PHAT Collaboration; SPLASH Collaboration
2013-01-01
We explore the spectroscopic properties of a couple hundred carbon stars discovered in the disk of the Andromeda galaxy (M31) in the course of the Spectroscopic and Photometric Landscape of Andromeda's Stellar Halo (SPLASH) survey. The spectra were obtained using the DEIMOS spectrograph on the Keck II 10-meter telescope. About 5000 stars were targeted for spectroscopy during observing runs in 2010 and 2011 using DEIMOS's 1200 lines/mm grating with a spectral resolving power of R ~ 5000 to 6000 and spectral coverage from 6500-9000 Angstrom. In September 2012, another 5000 stars were observed this time with the 600 lines/mm grating and R ~ 2500 and spectral coverage from 4500-9000 Angstrom. For both types of spectroscopic observations, targets were selected from the Panchromatic Hubble Andromeda Treasury (PHAT) multi-cycle treasury program with the Hubble Space Telescope. Six-filter photometry in the ultraviolet (F275W, F336W), optical (F439W, F814W), and near infrared (F110W, F160W) is available for most targets. These carbon star samples are used to constrain the intermediage-age population in M31's disk. They are also compared to spectra of previously known carbon samples in the dwarf elliptical satellites of M31, NGC 147, NGC 185, and NGC 205. The authors thank the National Science Foundation, NASA/STScI, and UCSC's Summer Internship Program for support.
Low power multi-camera system and algorithms for automated threat detection
NASA Astrophysics Data System (ADS)
Huber, David J.; Khosla, Deepak; Chen, Yang; Van Buer, Darrel J.; Martin, Kevin
2013-05-01
A key to any robust automated surveillance system is continuous, wide field-of-view sensor coverage and high accuracy target detection algorithms. Newer systems typically employ an array of multiple fixed cameras that provide individual data streams, each of which is managed by its own processor. This array can continuously capture the entire field of view, but collecting all the data and back-end detection algorithm consumes additional power and increases the size, weight, and power (SWaP) of the package. This is often unacceptable, as many potential surveillance applications have strict system SWaP requirements. This paper describes a wide field-of-view video system that employs multiple fixed cameras and exhibits low SWaP without compromising the target detection rate. We cycle through the sensors, fetch a fixed number of frames, and process them through a modified target detection algorithm. During this time, the other sensors remain powered-down, which reduces the required hardware and power consumption of the system. We show that the resulting gaps in coverage and irregular frame rate do not affect the detection accuracy of the underlying algorithms. This reduces the power of an N-camera system by up to approximately N-fold compared to the baseline normal operation. This work was applied to Phase 2 of DARPA Cognitive Technology Threat Warning System (CT2WS) program and used during field testing.
Abbas, Ahmar S; Moseley, Douglas; Kassam, Zahra; Kim, Sun Mo; Cho, Charles
2013-05-06
Recently, volumetric-modulated arc therapy (VMAT) has demonstrated the ability to deliver radiation dose precisely and accurately with a shorter delivery time compared to conventional intensity-modulated fixed-field treatment (IMRT). We applied the hypothesis of VMAT technique for the treatment of thoracic esophageal carcinoma to determine superior or equivalent conformal dose coverage for a large thoracic esophageal planning target volume (PTV) with superior or equivalent sparing of organs-at-risk (OARs) doses, and reduce delivery time and monitor units (MUs), in comparison with conventional fixed-field IMRT plans. We also analyzed and compared some other important metrics of treatment planning and treatment delivery for both IMRT and VMAT techniques. These metrics include: 1) the integral dose and the volume receiving intermediate dose levels between IMRT and VMATI plans; 2) the use of 4D CT to determine the internal motion margin; and 3) evaluating the dosimetry of every plan through patient-specific QA. These factors may impact the overall treatment plan quality and outcomes from the individual planning technique used. In this study, we also examined the significance of using two arcs vs. a single-arc VMAT technique for PTV coverage, OARs doses, monitor units and delivery time. Thirteen patients, stage T2-T3 N0-N1 (TNM AJCC 7th edn.), PTV volume median 395 cc (range 281-601 cc), median age 69 years (range 53 to 85), were treated from July 2010 to June 2011 with a four-field (n = 4) or five-field (n = 9) step-and-shoot IMRT technique using a 6 MV beam to a prescribed dose of 50 Gy in 20 to 25 F. These patients were retrospectively replanned using single arc (VMATI, 91 control points) and two arcs (VMATII, 182 control points). All treatment plans of the 13 study cases were evaluated using various dose-volume metrics. These included PTV D99, PTV D95, PTV V9547.5Gy(95%), PTV mean dose, Dmax, PTV dose conformity (Van't Riet conformation number (CN)), mean lung dose, lung V20 and V5, liver V30, and Dmax to the spinal canal prv3mm. Also examined were the total plan monitor units (MUs) and the beam delivery time. Equivalent target coverage was observed with both VMAT single and two-arc plans. The comparison of VMATI with fixed-field IMRT demonstrated equivalent target coverage; statistically no significant difference were found in PTV D99 (p = 0.47), PTV mean (p = 0.12), PTV D95 and PTV V9547.5Gy (95%) (p = 0.38). However, Dmax in VMATI plans was significantly lower compared to IMRT (p = 0.02). The Van't Riet dose conformation number (CN) was also statistically in favor of VMATI plans (p = 0.04). VMATI achieved lower lung V20 (p = 0.05), whereas lung V5 (p = 0.35) and mean lung dose (p = 0.62) were not significantly different. The other OARs, including spinal canal, liver, heart, and kidneys showed no statistically significant differences between the two techniques. Treatment time delivery for VMATI plans was reduced by up to 55% (p = 5.8E-10) and MUs reduced by up to 16% (p = 0.001). Integral dose was not statistically different between the two planning techniques (p = 0.99). There were no statistically significant differences found in dose distribution of the two VMAT techniques (VMATI vs. VMATII) Dose statistics for both VMAT techniques were: PTV D99 (p = 0.76), PTV D95 (p = 0.95), mean PTV dose (p = 0.78), conformation number (CN) (p = 0.26), and MUs (p = 0.1). However, the treatment delivery time for VMATII increased significantly by two-fold (p = 3.0E-11) compared to VMATI. VMAT-based treatment planning is safe and deliverable for patients with thoracic esophageal cancer with similar planning goals, when compared to standard IMRT. The key benefit for VMATI was the reduction in treatment delivery time and MUs, and improvement in dose conformality. In our study, we found no significant difference in VMATII over single-arc VMATI for PTV coverage or OARs doses. However, we observed significant increase in delivery time for VMATII compared to VMATI.
Nkiwane, Karen S; Pötter, Richard; Tanderup, Kari; Federico, Mario; Lindegaard, Jacob C; Kirisits, Christian
2013-01-01
Three-dimensional evaluation and comparison of target and organs at risk (OARs) doses from two traditional standard source loading patterns in the frame of MRI-guided cervical cancer brachytherapy for various clinical scenarios based on patient data collected in a multicenter trial setting. Two nonoptimized three-dimensional MRI-based treatment plans, Plan 1 (tandem and vaginal loading) and Plan 2 (tandem loading only), were generated for 134 patients from seven centers participating in the EMBRACE study. Both plans were normalized to point A (Pt. A). Target and OAR doses were evaluated in terms of minimum dose to 90% of the high-risk clinical target volume (HRCTV D90) grouped by tumor stage and minimum dose to the most exposed 2cm³ of the OARs volume. An HRCTV D90 ≥ Pt. A was achieved in 82% and 44% of the patients with Plans 1 and 2, respectively. Median HRCTV D90 with Plans 1 and 2 was 120% and 90% of Pt. A dose, respectively. Both plans had optimal dose coverage in 88% of Stage IB tumors; however, the tandem-only plan resulted in about 50% of dose reduction to the vagina and rectum. For Stages IIB and IIIB, Plan 1 had on average 35% better target coverage but with significant doses to OARs. Standard tandem loading alone results in good target coverage in most Stage IB tumors without violating OAR dose constraints. For Stage IIB tumors, standard vaginal loading improves the therapeutic window, however needs optimization to fulfill the dose prescription for target and OAR. In Stage IIIB, even optimized vaginal loading often does not fulfill the needs for dose prescription. The significant dose variation across various clinical scenarios for both target and OARs indicates the need for image-guided brachytherapy for optimal dose adaptation both for limited and advanced diseases. Copyright © 2013 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.
Cross-National Differences in Special Education Coverage: An Empirical Analysis
ERIC Educational Resources Information Center
Anastasiou, Dimitris; Keller, Clayton E.
2014-01-01
This study investigated the role of educational and socioeconomic factors in explaining differences in national special education coverage. Data were derived from several international and governmental sources, targeting the year 2008 and covering 143 countries. Descriptive statistics revealed huge disparities in access to special education among…
Knowles, Jacky M; Garrett, Greg S; Gorstein, Jonathan; Kupka, Roland; Situma, Ruth; Yadav, Kapil; Yusufali, Rizwan; Pandav, Chandrakant; Aaron, Grant J
2017-01-01
Background: Household coverage with iodized salt was assessed in 10 countries that implemented Universal Salt Iodization (USI). Objective: The objective of this paper was to summarize household coverage data for iodized salt, including the relation between coverage and residence type and socioeconomic status (SES). Methods: A review was conducted of results from cross-sectional multistage household cluster surveys with the use of stratified probability proportional to size design in Bangladesh, Ethiopia, Ghana, India, Indonesia, Niger, the Philippines, Senegal, Tanzania, and Uganda. Salt iodine content was assessed with quantitative methods in all cases. The primary indicator of coverage was percentage of households that used adequately iodized salt, with an additional indicator for salt with some added iodine. Indicators of risk were SES and residence type. We used 95% CIs to determine significant differences in coverage. Results: National household coverage of adequately iodized salt varied from 6.2% in Niger to 97.0% in Uganda. For salt with some added iodine, coverage varied from 52.4% in the Philippines to 99.5% in Uganda. Coverage with adequately iodized salt was significantly higher in urban than in rural households in Bangladesh (68.9% compared with 44.3%, respectively), India (86.4% compared with 69.8%, respectively), Indonesia (59.3% compared with 51.4%, respectively), the Philippines (31.5% compared with 20.2%, respectively), Senegal (53.3% compared with 19.0%, respectively), and Tanzania (89.2% compared with 57.6%, respectively). In 7 of 8 countries with data, household coverage of adequately iodized salt was significantly higher in high- than in low-SES households in Bangladesh (58.8% compared with 39.7%, respectively), Ghana (36.2% compared with 21.5%, respectively), India (80.6% compared with 70.5%, respectively), Indonesia (59.9% compared with 45.6%, respectively), the Philippines (39.4% compared with 17.3%, respectively), Senegal (50.7% compared with 27.6%, respectively) and Tanzania (80.9% compared with 51.3%, respectively). Conclusions: Uganda has achieved USI. In other countries, access to iodized salt is inequitable. Quality control and regulatory enforcement of salt iodization remain challenging. Notable progress toward USI has been made in Ethiopia and India. Assessing progress toward USI only through household salt does not account for potentially iodized salt consumed through processed foods. PMID:28404840
Knowles, Jacky M; Garrett, Greg S; Gorstein, Jonathan; Kupka, Roland; Situma, Ruth; Yadav, Kapil; Yusufali, Rizwan; Pandav, Chandrakant; Aaron, Grant J
2017-05-01
Background: Household coverage with iodized salt was assessed in 10 countries that implemented Universal Salt Iodization (USI). Objective: The objective of this paper was to summarize household coverage data for iodized salt, including the relation between coverage and residence type and socioeconomic status (SES). Methods: A review was conducted of results from cross-sectional multistage household cluster surveys with the use of stratified probability proportional to size design in Bangladesh, Ethiopia, Ghana, India, Indonesia, Niger, the Philippines, Senegal, Tanzania, and Uganda. Salt iodine content was assessed with quantitative methods in all cases. The primary indicator of coverage was percentage of households that used adequately iodized salt, with an additional indicator for salt with some added iodine. Indicators of risk were SES and residence type. We used 95% CIs to determine significant differences in coverage. Results: National household coverage of adequately iodized salt varied from 6.2% in Niger to 97.0% in Uganda. For salt with some added iodine, coverage varied from 52.4% in the Philippines to 99.5% in Uganda. Coverage with adequately iodized salt was significantly higher in urban than in rural households in Bangladesh (68.9% compared with 44.3%, respectively), India (86.4% compared with 69.8%, respectively), Indonesia (59.3% compared with 51.4%, respectively), the Philippines (31.5% compared with 20.2%, respectively), Senegal (53.3% compared with 19.0%, respectively), and Tanzania (89.2% compared with 57.6%, respectively). In 7 of 8 countries with data, household coverage of adequately iodized salt was significantly higher in high- than in low-SES households in Bangladesh (58.8% compared with 39.7%, respectively), Ghana (36.2% compared with 21.5%, respectively), India (80.6% compared with 70.5%, respectively), Indonesia (59.9% compared with 45.6%, respectively), the Philippines (39.4% compared with 17.3%, respectively), Senegal (50.7% compared with 27.6%, respectively) and Tanzania (80.9% compared with 51.3%, respectively). Conclusions: Uganda has achieved USI. In other countries, access to iodized salt is inequitable. Quality control and regulatory enforcement of salt iodization remain challenging. Notable progress toward USI has been made in Ethiopia and India. Assessing progress toward USI only through household salt does not account for potentially iodized salt consumed through processed foods.
Evaluation of the clinical usefulness of modulated arc treatment
NASA Astrophysics Data System (ADS)
Lee, Young Kyu; Jang, Hong Seok; Kim, Yeon Sil; Choi, Byung Ock; Kang, Young-Nam; Nam, Sang Hee; Park, Hyeong Wook; Kim, Shin Wook; Shin, Hun Joo; Lee, Jae Choon; Kim, Ji Na; Park, Sung Kwang; Kim, Jin Young
2015-07-01
The purpose of this study is to evaluate the clinical usefulness of modulated arc (mARC) treatment techniques. The mARC treatment plans for non-small-cell lung cancer (NSCLC) patients were made in order to verify the clinical usefulness of mARC. A pre-study was conducted to find the best plan condition for mARC treatment, and the usefulness of the mARC treatment plan was evaluated by comparing it with other Arc treatment plans such as tomotherapy and RapidArc plans. In the case of mARC, the optimal condition for the mARC plan was determined by comparing the dosimetric performance of the mARC plans developed by using various parameters, which included the photon energy (6 MV, 10 MV), the optimization point angle (6°- 10°intervals), and the total number of segments (36 - 59 segments). The best dosimetric performance of mARC was observed at a 10 MV photon energy, a point angle 6 degrees, and 59 segments. The treatment plans for the three different techniques were compared by using the following parameters: the conformity index (CI), homogeneity index (HI), the target coverage, the dose to the OARs, the number of monitor units (MU), the beam on time, and the normal tissue complication probability (NTCP). As a result, the three different treatment techniques showed similar target coverages. The mARC plan had the lowest V20 (volume of lung receiving > 20 Gy) and MU per fraction compared with both the RapidArc and the tomotherapy plans. The mARC plan reduced the beam on time as well. Therefore, the results of this study provide satisfactory evidence that the mARC technique can be considered as a useful clinical technique for radiation treatment.
42 CFR 435.229 - Optional targeted low-income children.
Code of Federal Regulations, 2012 CFR
2012-10-01
... 42 Public Health 4 2012-10-01 2012-10-01 false Optional targeted low-income children. 435.229... Coverage of Families and Children § 435.229 Optional targeted low-income children. The agency may provide Medicaid to— (a) All individuals under age 19 who are optional targeted low-income children as defined in...
42 CFR 435.229 - Optional targeted low-income children.
Code of Federal Regulations, 2010 CFR
2010-10-01
... 42 Public Health 4 2010-10-01 2010-10-01 false Optional targeted low-income children. 435.229... Coverage of Families and Children § 435.229 Optional targeted low-income children. The agency may provide Medicaid to— (a) All individuals under age 19 who are optional targeted low-income children as defined in...
42 CFR 435.229 - Optional targeted low-income children.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 42 Public Health 4 2011-10-01 2011-10-01 false Optional targeted low-income children. 435.229... Coverage of Families and Children § 435.229 Optional targeted low-income children. The agency may provide Medicaid to— (a) All individuals under age 19 who are optional targeted low-income children as defined in...
Coverage-guaranteed sensor node deployment strategies for wireless sensor networks.
Fan, Gaojuan; Wang, Ruchuan; Huang, Haiping; Sun, Lijuan; Sha, Chao
2010-01-01
Deployment quality and cost are two conflicting aspects in wireless sensor networks. Random deployment, where the monitored field is covered by randomly and uniformly deployed sensor nodes, is an appropriate approach for large-scale network applications. However, their successful applications depend considerably on the deployment quality that uses the minimum number of sensors to achieve a desired coverage. Currently, the number of sensors required to meet the desired coverage is based on asymptotic analysis, which cannot meet deployment quality due to coverage overestimation in real applications. In this paper, we first investigate the coverage overestimation and address the challenge of designing coverage-guaranteed deployment strategies. To overcome this problem, we propose two deployment strategies, namely, the Expected-area Coverage Deployment (ECD) and BOundary Assistant Deployment (BOAD). The deployment quality of the two strategies is analyzed mathematically. Under the analysis, a lower bound on the number of deployed sensor nodes is given to satisfy the desired deployment quality. We justify the correctness of our analysis through rigorous proof, and validate the effectiveness of the two strategies through extensive simulation experiments. The simulation results show that both strategies alleviate the coverage overestimation significantly. In addition, we also evaluate two proposed strategies in the context of target detection application. The comparison results demonstrate that if the target appears at the boundary of monitored region in a given random deployment, the average intrusion distance of BOAD is considerably shorter than that of ECD with the same desired deployment quality. In contrast, ECD has better performance in terms of the average intrusion distance when the invasion of intruder is from the inside of monitored region.
Routinely vaccinating adolescents against meningococcus: targeting transmission & disease.
Vetter, Volker; Baxter, Roger; Denizer, Gülhan; Sáfadi, Marco A P; Silfverdal, Sven-Arne; Vyse, Andrew; Borrow, Ray
2016-05-01
Adolescents have the highest rates of meningococcal carriage and transmission. Interrupting the adolescent habitat in order to reduce carriage and transmission within adolescents and to other age groups could help to control meningococcal disease at a population level. Compared to immunization strategies restricted to young children, a strategy focused on adolescents may have more profound and long-lasting indirect impacts, and may be more cost effective. Despite challenges in reaching this age-group, experience with other vaccines show that high vaccine coverage of adolescents is attainable.
Hoest, Christel; Seidman, Jessica C; Lee, Gwenyth; Platts-Mills, James A; Ali, Asad; Olortegui, Maribel Paredes; Bessong, Pascal; Chandyo, Ram; Babji, Sudhir; Mohan, Venkata Raghava; Mondal, Dinesh; Mahfuz, Mustafa; Mduma, Estomih R; Nyathi, Emanuel; Abreu, Claudia; Miller, Mark A; Pan, William; Mason, Carl J; Knobler, Stacey L
2017-01-11
Launched in 1974, the Expanded Program on Immunization (EPI) is estimated to prevent two-three million deaths annually from polio, diphtheria, tuberculosis, pertussis, measles, and tetanus. Additional lives could be saved through better understanding what influences adherence to the EPI schedule in specific settings. The Etiology, Risk Factors and Interactions of Enteric Infections and Malnutrition and the Consequences for Child Health and Development (MAL-ED) study followed cohorts in eight sites in South Asia, Africa, and South America and monitored vaccine receipt over the first two years of life for the children enrolled in the study. Vaccination histories were obtained monthly from vaccination cards, local clinic records and/or caregiver reports. Vaccination histories were compared against the prescribed EPI schedules for each country, and coverage rates were examined in relation to the timing of vaccination. The influence of socioeconomic factors on vaccine timing and coverage was also considered. Coverage rates for EPI vaccines varied between sites and by type of vaccine; overall, coverage was highest in the Nepal and Bangladesh sites and lowest in the Tanzania and Brazil sites. Bacillus Calmette-Guérin coverage was high across all sites, 87-100%, whereas measles vaccination rates ranged widely, 73-100%. Significant delays between the scheduled administration age and actual vaccination date were present in all sites, especially for measles vaccine where less than 40% were administered on schedule. A range of socioeconomic factors were significantly associated with vaccination status in study children but these results were largely site-specific. Our findings highlight the need to improve measles vaccination rates and reduce delayed vaccination to achieve EPI targets related to the establishment of herd immunity and reduction in disease transmission. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.
Increased immunization coverage addresses the equity gap in Nepal
Nelin, Viktoria; Raaijmakers, Hendrikus; Kim, Hyung Joon; Singh, Chahana; Målqvist, Mats
2017-01-01
Abstract Objective To compare immunization coverage and equity distribution of coverage between 2001 and 2014 in Nepal. Methods We used data from the Demographic and Health Surveys carried out in 2001, 2006 and 2011 together with data from the 2014 Multiple Indicator Cluster Survey. We calculated the proportion, in mean percentage, of children who had received bacille Calmette–Guérin (BCG) vaccine, three doses of polio vaccine, three doses of diphtheria–pertussis–tetanus (DPT) vaccine and measles vaccine. To measure inequities between wealth quintiles, we calculated the slope index of inequality (SII) and relative index of inequality (RII) for all surveys. Findings From 2001 to 2014, the proportion of children who received all vaccines at the age of 12 months increased from 68.8% (95% confidence interval, CI: 67.5–70.1) to 82.4% (95% CI: 80.7–84.0). While coverage of BCG, DPT and measles immunization statistically increased during the study period, the proportion of children who received the third dose of polio vaccine decreased from 93.3% (95% CI: 92.7–93.9) to 88.1% (95% CI: 86.8–89.3). The poorest wealth quintile showed the greatest improvement in immunization coverage, from 58% to 77.9%, while the wealthiest quintile only improved from 84.8% to 86.0%. The SII for children who received all vaccines improved from 0.070 (95% CI: 0.061–0.078) to 0.026 (95% CI: 0.013–0.039) and RII improved from 1.13 to 1.03. Conclusion The improvement in immunization coverage between 2001 and 2014 in Nepal can mainly be attributed to the interventions targeting the disadvantaged populations. PMID:28479621
DOE Office of Scientific and Technical Information (OSTI.GOV)
Price, A; Chang, S; Matney, J
2016-06-15
Purpose: Tomotherapy has unique challenges in handling intrafractional motion compared to conventional LINAC. In this study, we analyzed the impact of intrafractional motion on cumulative dosimetry using actual patient motion data and investigated real time jaw/MLC compensation approaches to minimize the motion-induced dose discrepancy in Tomotherapy SBRT treatment. Methods: Intrafractional motion data recorded in two CyberKnife lung treatment cases through fiducial tracking and two LINAC prostate cases through Calypso tracking were used in this study. For each treatment site, one representative case has an average motion (6mm) and one has a large motion (10mm for lung and 15mm for prostate).more » The cases were re-planned on Tomotherapy for SBRT. Each case was planned with 3 different jaw settings: 1cm static, 2.5cm dynamic, and 5cm dynamic. 4D dose accumulation software was developed to compute dose with the recorded motions and theoretically compensate motions by modifying original jaw and MLC to track the trajectory of the tumor. Results: PTV coverage in Tomotherapy SBRT for patients with intrafractional motion depends on motion type, amplitude and plan settings. For the prostate patient with large motion, PTV coverage changed from 97.2% (motion-free) to 47.1% (target motion-included), 96.6% to 58.5% and 96.3% to 97.8% for the 1cm static jaw, 2.5cm dynamic jaw and 5cm dynamic jaw setting, respectively. For the lung patient with large motion, PTV coverage discrepancies showed a similar trend of change. When the jaw and MLC compensation program was engaged, the motion compromised PTV coverage was recovered back to >95% for all cases and plans. All organs at risk (OAR) were spared with < 5% increase from original motion-free plans. Conclusion: Tomotherapy SBRT is less motion-impacted when 5cm dynamic jaw is used. Once the motion pattern is known, the jaw and MLC compensation program can largely minimize the compromised target coverage and OAR sparing.« less
Interactive dose shaping part 2: proof of concept study for six prostate patients
NASA Astrophysics Data System (ADS)
Kamerling, Cornelis Ph; Ziegenhein, Peter; Sterzing, Florian; Oelfke, Uwe
2016-03-01
Recently we introduced interactive dose shaping (IDS) as a new IMRT planning strategy. This planning concept is based on a hierarchical sequence of local dose modification and recovery operations. The purpose of this work is to provide a feasibility study for the IDS planning strategy based on a small set of six prostate patients. The IDS planning paradigm aims to perform interactive local dose adaptations of an IMRT plan without compromising already established valuable dose features in real-time. Various IDS tools were developed in our in-house treatment planning software Dynaplan and were utilized to create IMRT treatment plans for six patients with an adeno-carcinoma of the prostate. The sequenced IDS treatment plans were compared to conventionally optimized clinically approved plans (9 beams, co-planar). For each patient, several IDS plans were created, with different trade-offs between organ sparing and target coverage. The reference dose distributions were imported into Dynaplan. For each patient, the IDS treatment plan with a similar or better trade-off between target coverage and OAR sparing was selected for plan evaluation, guided by a physician. For this initial study we were able to generate treatment plans for prostate geometries in 15-45 min. Individual local dose adaptations could be performed in less than one second. The average differences compared to the reference plans were for the mean dose: 0.0 Gy (boost) and 1.2 Gy (PTV), for {{D}98%}:-1.1 Gy and for {{D}2%}:1.1 Gy (both target volumes). The dose-volume quality indicators were well below the Quantec constraints. However, we also observed limitations of our currently implemented approach. Most prominent was an increase of the non-tumor integral dose by 16.4% on average, demonstrating that further developments of our planning strategy are required.
Accelerated Partial Breast Irradiation: What is Dosimetric Effect of Advanced Technology Approaches?
DOE Office of Scientific and Technical Information (OSTI.GOV)
Moran, Jean M.; Ben-David, Merav A.; Marsh, Robin B.
2009-09-01
Purpose: The present treatment planning study compared whole breast radiotherapy (WBRT) to accelerated partial breast irradiation (APBI) for different external beam techniques and geometries (e.g., free breathing [FB] and deep inspiration breath hold [DIBH]). Methods and Materials: After approval by our institutional review board, a treatment planning study was performed of 10 patients with left-sided Stage 0-I breast cancer enrolled in a Phase I-II study of APBI using intensity-modulated radiotherapy (IMRT). After lumpectomy, patients underwent planning computed tomography scans during FB and using an active breathing control device at DIBH. For the FB geometry, standard WBRT and three-dimensional conformal radiotherapymore » (3D-CRT) APBI plans were created. For the DIBH geometry with active breathing control, WBRT, 3D-CRT, and IMRT APBI plans were created. Results: All APBI techniques had excellent planning target volume coverage. The maximal planning target volume dose was reduced from 116% of the prescription dose to 108% with the IMRT(DIBH) APBI plan. The maximal heart dose was >30 Gy for the WBRT techniques, 8.2 Gy for 3D-CRT(FB), and <5.0 Gy for 3D-CRT(DIBH) and IMRT(DIBH) techniques. The mean left anterior descending artery dose was significantly reduced from 11.4 Gy with WBRT(FB) to 4.2 with WBRT(DIBH) and <2.0 Gy with all APBI techniques. Conclusion: Although planning target volume coverage was acceptable with all techniques, the plans using the DIBH geometry resulted in a marked reduction in the normal tissue dose compared with WBRT planned in the absence of cardiac blocking. Additional study is needed to determine whether these techniques result in clinical benefits.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Tamilarasu, Suresh; Saminathan, Madeswaran
Purpose: Aim of the current study is to look plan quality, treatment beam ON time for IMRT using 6MV FB (Flatten Beam) and FFFB (Flattening Filter Free Beam) in left breast cancer cases. Methods: Ten left breast cancer patients treated with breast conserving surgical (BCS) procedure approach and adjuvant radiotherapy were selected from the department database. Simultaneous Integrated boost (SIB) technique was used to irradiate the total left breast (PTV) to a dose of 50.40Gy with concomitant enhance to the lumpectomy cavity known as gross tumour volume (GTV) to a dose of 59.40Gy in 28 fractions. Plans 6MV FB IMRTmore » and 6MV FFFB IMRT had been generated to achieve dose to 95% target volume (TV) and spare Organ at risks (OAR’s). Homogeneity index (HI), conformity index (CI), treatment monitor unit (MU),normal tissues integral dose (NTID) and low dose volume of normal tissue were compared. Results: There was no statistically huge difference among the plans with respect to target volume coverage, CI HI, Ipsilateral Lung and Breast. But statistically significant difference (p< 0.05) as observed in Heart, V5Gy of Contralateral Lung, MU’s NTID and low dose volume of normal tissue. Conclusion: 6MV FB and FFF beam produce almost equivalent plans in IMRT modality with admire to target volume coverage, HI, CI. Beam on time and NTID was determined to be much less in 6MV FFFB IMRT. FFF beam leads to a time saving treatment delivery and fewer NTID in cancer of left breast cases.« less
Multi-Agent Cooperative Target Search
Hu, Jinwen; Xie, Lihua; Xu, Jun; Xu, Zhao
2014-01-01
This paper addresses a vision-based cooperative search for multiple mobile ground targets by a group of unmanned aerial vehicles (UAVs) with limited sensing and communication capabilities. The airborne camera on each UAV has a limited field of view and its target discriminability varies as a function of altitude. First, by dividing the whole surveillance region into cells, a probability map can be formed for each UAV indicating the probability of target existence within each cell. Then, we propose a distributed probability map updating model which includes the fusion of measurement information, information sharing among neighboring agents, information decay and transmission due to environmental changes such as the target movement. Furthermore, we formulate the target search problem as a multi-agent cooperative coverage control problem by optimizing the collective coverage area and the detection performance. The proposed map updating model and the cooperative control scheme are distributed, i.e., assuming that each agent only communicates with its neighbors within its communication range. Finally, the effectiveness of the proposed algorithms is illustrated by simulation. PMID:24865884
Minetti, Andrea; Hurtado, Northan; Grais, Rebecca F.; Ferrari, Matthew
2014-01-01
Current mass vaccination campaigns in measles outbreak response are nonselective with respect to the immune status of individuals. However, the heterogeneity in immunity, due to previous vaccination coverage or infection, may lead to potential bias of such campaigns toward those with previous high access to vaccination and may result in a lower-than-expected effective impact. During the 2010 measles outbreak in Malawi, only 3 of the 8 districts where vaccination occurred achieved a measureable effective campaign impact (i.e., a reduction in measles cases in the targeted age groups greater than that observed in nonvaccinated districts). Simulation models suggest that selective campaigns targeting hard-to-reach individuals are of greater benefit, particularly in highly vaccinated populations, even for low target coverage and with late implementation. However, the choice between targeted and nonselective campaigns should be context specific, achieving a reasonable balance of feasibility, cost, and expected impact. In addition, it is critical to develop operational strategies to identify and target hard-to-reach individuals. PMID:24131555
Degtiar, Irina
2017-12-01
Personalized medicine and orphan drugs share many characteristics-both target small patient populations, have uncertainties regarding efficacy and safety at payer submission, and frequently have high prices. Given personalized medicine's rising importance, this review summarizes international coverage and pricing strategies for personalized medicine and orphan drugs as well as their impact on therapy development incentives, payer budgets, and therapy access and utilization. PubMed, Health Policy Reference Center, EconLit, Google Scholar, and references were searched through February 2017 for articles presenting primary data. Sixty-nine articles summarizing 42 countries' strategies were included. Therapy evaluation criteria varied between countries, as did patient cost-share. Payers primarily valued clinical effectiveness; cost was only considered by some. These differences result in inequities in orphan drug access, particularly in smaller and lower-income countries. The uncertain reimbursement process hinders diagnostic testing. Payer surveys identified lack of comparative effectiveness evidence as a chief complaint, while manufacturers sought more clarity on payer evidence requirements. Despite lack of strong evidence, orphan drugs largely receive positive coverage decisions, while personalized medicine diagnostics do not. As more personalized medicine and orphan drugs enter the market, registries can provide better quality evidence on their efficacy and safety. Payers need systematic assessment strategies that are communicated with more transparency. Further studies are necessary to compare the implications of different payer approaches. Copyright © 2017 Elsevier B.V. All rights reserved.
A 4D-optimization concept for scanned ion beam therapy.
Graeff, Christian; Lüchtenborg, Robert; Eley, John Gordon; Durante, Marco; Bert, Christoph
2013-12-01
Scanned carbon beam therapy offers advantageous dose distributions and an increased biological effect. Treating moving targets is complex due to sensitivity to range changes and interplay. We propose a 4D treatment planning concept that considers motion during particle number optimization. The target was subdivided into sectors, one for each motion phase of a 4D-CT. Each sector was non-rigidly transformed to its motion phase and there targeted by a dedicated raster field (RST). Therefore, the resulting 4D-RST compensated target motion and range changes. A 4D treatment control system (TCS) was needed for synchronized delivery to the measured patient motion. 4D-optimized plans were simulated for 9 NSCLC lung cancer patients and compared to static irradiation at end-exhale. A prototype TCS was implemented and successfully tested in a film experiment. The 4D-optimized treatment plan resulted in only slightly lower dose coverage of the target compared to static optimization, with V 95% of 97.9% (median, range 96.5-99.4%) vs. 99.3% (98.5-99.8%), with negligible overdose. The conformity number was comparable at 88.2% (85.1-92.5%) vs. 85.2% (79.9-91.2%) for 4D and static, respectively. We implemented and tested a 4D treatment plan optimization method resulting in highly conformal dose delivery. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Leicher, Brian, E-mail: bleicher@wpahs.org; Day, Ellen; Colonias, Athanasios
2014-10-01
To describe a dosimetric method using an anterior dose avoidance structure (ADAS) during the treatment planning process for intensity-modulated radiation therapy (IMRT) for patients with anal canal and rectal carcinomas. A total of 20 patients were planned on the Elekta/CMS XiO treatment planning system, version 4.5.1 (Maryland Heights MO) with a superposition algorithm. For each patient, 2 plans were created: one employing an ADAS (ADAS plan) and the other replanned without an ADAS (non-ADAS plan). The ADAS was defined to occupy the volume between the inguinal nodes and primary target providing a single organ at risk that is completely outsidemore » of the target volume. Each plan used the same beam parameters and was analyzed by comparing target coverage, overall plan dose conformity using a conformity number (CN) equation, bowel dose-volume histograms, and the number of segments, daily treatment duration, and global maximum dose. The ADAS and non-ADAS plans were equivalent in target coverage, mean global maximum dose, and sparing of small bowel in low-dose regions (5, 10, 15, and 20 Gy). The mean difference between the CN value for the non-ADAS plans and ADAS plans was 0.04 ± 0.03 (p < 0.001). The mean difference in the number of segments was 15.7 ± 12.7 (p < 0.001) in favor of ADAS plans. The ADAS plan delivery time was shorter by 2.0 ± 1.5 minutes (p < 0.001) than the non-ADAS one. The ADAS has proven to be a powerful tool when planning rectal and anal canal IMRT cases with critical structures partially contained inside the target volume.« less
Soh, Jun Hui; Lin, Yiyang; Rana, Subinoy; Ying, Jackie Y; Stevens, Molly M
2015-08-04
A versatile and sensitive colorimetric assay that allows the rapid detection of small-molecule targets using the naked eye is demonstrated. The working principle of the assay integrates aptamer-target recognition and the aptamer-controlled growth of gold nanoparticles (Au NPs). Aptamer-target interactions modulate the amount of aptamer strands adsorbed on the surface of aptamer-functionalized Au NPs via desorption of the aptamer strands when target molecules bind with the aptamer. Depending on the resulting aptamer coverage, Au NPs grow into morphologically varied nanostructures, which give rise to different colored solutions. Au NPs with low aptamer coverage grow into spherical NPs, which produce red-colored solutions, whereas Au NPs with high aptamer coverage grow into branched NPs, which produce blue-colored solutions. We achieved visible colorimetric response and nanomolar detection limits for the detection of ochratoxin A (1 nM) in red wine samples, as well as cocaine (1 nM) and 17β-estradiol (0.2 nM) in spiked synthetic urine and saliva, respectively. The detection limits were well within clinically and physiologically relevant ranges, and below the maximum food safety limits. The assay is highly sensitive, specific, and able to detect an array of analytes rapidly without requiring sophisticated equipment, making it relevant for many applications, such as high-throughput drug and clinical screening, food sampling, and diagnostics. Furthermore, the assay is easily adapted as a chip-based platform for rapid and portable target detection.
Health Insurance Coverage and Access to Care Among US-Born and Foreign-Born Sexual Minorities.
Gonzales, Gilbert; Dedania, Reema; Driscoll, Ryan
2018-06-26
Sexual minorities and immigrants face unique challenges to accessing health care in the United States. This study used data on nonelderly adults (n = 100,667) from the 2013-2016 National Health Interview Survey. Unadjusted prevalence estimates and multivariable logistic regression models (with and without interactions between immigration and sexual minority status) were used to compare health insurance coverage and access to care by immigration and sexual minority status. We did not find any differences in uninsurance, having a usual source of care, and a recent office visit by sexual orientation for US-born and foreign-born adults. However, compared to their heterosexual counterparts, US-born and foreign-born sexual minorities were more likely to have an emergency room visit in the prior year and report financial-related barriers to medical care, dental care, prescription medications, and mental health care. Foreign-born sexual minorities were more likely to have an emergency room visit and unmet mental health care needs due to cost compared to other subpopulations after controlling for sociodemographic characteristics. Broadening the knowledge and scope of research on sexual minority immigrants can inform targeted health policy approaches with the goal of achieving health equity for sexual minority immigrants.
Anderson, N; Lawford, C; Khoo, V; Rolfo, M; Joon, D L; Wada, M
2011-12-01
Intensity-modulated radiotherapy (IMRT) has reduced the impact of acute and late toxicities associated with head and neck radiotherapy. Treatment planning system (TPS) advances in biological cost function based optimization (BBO) and improved segmentation techniques have increased organ at risk (OAR) sparing compared to conventional dose-based optimization (DBO). A planning study was undertaken to compare OAR avoidance in DBO and BBO treatment planning. Simultaneous integrated boost treatment plans were produced for 10 head and neck patients using both planning systems. Plans were compared for tar get coverage and OAR avoidance. Comparisons were made using the BBO TPS Monte Carlo dose engine to eliminate differences due to inherent algorithms. Target coverage (V95%) was maintained for both solutions. BBO produced lower OAR doses, with statistically significant improvement to left (12.3%, p = 0.005) and right parotid mean dose (16.9%, p = 0.004), larynx V50_Gy (71.0%, p = 0.005), spinal cord (21.9%, p < 0.001) and brain stem dose maximums (31.5%, p = 0.002). This study observed improved OAR avoidance with BBO planning. Further investigations will be undertaken to review any clinical benefit of this improved planned dosimetry.
Anderson, N.; Lawford, C.; Khoo, V.; Rolfo, M.; Joon, D. Lim; Wada, M.
2011-01-01
Intensity-modulated radiotherapy (IMRT) has reduced the impact of acute and late toxicities associated with head and neck radiotherapy. Treatment planning system (TPS) advances in biological cost function based optimization (BBO) and improved segmentation techniques have increased organ at risk (OAR) sparing compared to conventional dose-based optimization (DBO). A planning study was undertaken to compare OAR avoidance in DBO and BBO treatment planning. Simultaneous integrated boost treatment plans were produced for 10 head and neck patients using both planning systems. Plans were compared for tar get coverage and OAR avoidance. Comparisons were made using the BBO TPS Monte Carlo dose engine to eliminate differences due to inherent algorithms. Target coverage (V95%) was maintained for both solutions. BBO produced lower OAR doses, with statistically significant improvement to left (12.3%, p = 0.005) and right parotid mean dose (16.9%, p = 0.004), larynx V50 Gy (71.0%, p = 0.005), spinal cord (21.9%, p < 0.001) and brain stem dose maximums (31.5%, p = 0.002). This study observed improved OAR avoidance with BBO planning. Further investigations will be undertaken to review any clinical benefit of this improved planned dosimetry. PMID:22066597
Lafort, Yves; Greener, Ross; Roy, Anuradha; Greener, Letitia; Ombidi, Wilkister; Lessitala, Faustino; Haghparast-Bidgoli, Hassan; Beksinska, Mags; Gichangi, Peter; Reza-Paul, Sushena; Smit, Jenni A; Chersich, Matthew; Delva, Wim
2016-01-01
A baseline cross-sectional survey among female sex workers (FSWs) was conducted in four cities within the context of an implementation research project aiming to improve FSWs' access to HIV, and sexual and reproductive health (SRH) services. The survey measured where FSWs seek HIV/SRH care and what motivates their choice. Using respondent-driven sampling (RDS), FWSs were recruited in Durban, South Africa (n = 400), Tete, Mozambique (n = 308), Mombasa, Kenya (n = 400) and Mysore, India (n = 458) and interviewed. RDS-adjusted proportions were estimated by non-parametric bootstrapping, and compared across cities using post-hoc pairwise comparison tests. Across cities, FSWs most commonly sought care for the majority of HIV/SRH services at public health facilities, most especially in Durban (ranging from 65% for condoms to 97% for HIV care). Services specifically targeting FSWs only had a high coverage in Mysore for STI care (89%) and HIV testing (79%). Private-for-profit clinics were important providers in Mombasa (ranging from 17% for STI care and HIV testing to 43% for HIV care), but not in the other cities. The most important reason for the choice of care provider in Durban and Mombasa was proximity, in Tete 'where they always go', and in Mysore cost of care. Where available, clinics specifically targeting FSWs were more often chosen because of shorter waiting times, perceived higher quality of care, more privacy and friendlier personnel. The place where care is sought for HIV/SRH services differs substantially between cities. Targeted services have limited coverage in the African cities compared to Mysore. Convenience appears more important for choosing the place of care than aspects of quality of care. The best model to improve access, linking targeted interventions with general health services, will need to be tailored to the specific context of each city.
Abdullah, Asnawi; Hort, Krishna; Abidin, Azwar Zaenal; Amin, Fadilah M
2012-01-01
Despite significant investment in improving service infrastructure and training of staff, public primary healthcare services in low-income and middle-income countries tend to perform poorly in reaching coverage targets. One of the factors identified in Aceh, Indonesia was the lack of operational funds for service provision. The objective of this study was to develop a simple and transparent costing tool that enables health planners to calculate the unit costs of providing basic health services to estimate additional budgets required to deliver services in accordance with national targets. The tool was developed using a standard economic approach that linked the input activities to achieving six national priority programs at primary healthcare level: health promotion, sanitation and environment health, maternal and child health and family planning, nutrition, immunization and communicable diseases control, and treatment of common illness. Costing was focused on costs of delivery of the programs that need to be funded by local government budgets. The costing tool consisting of 16 linked Microsoft Excel worksheets was developed and tested in several districts enabled the calculation of the unit costs of delivering of the six national priority programs per coverage target of each program (such as unit costs of delivering of maternal and child health program per pregnant mother). This costing tool can be used by health planners to estimate additional money required to achieve a certain level of coverage of programs, and it can be adjusted for different costs and program delivery parameters in different settings. Copyright © 2012 John Wiley & Sons, Ltd.
Ohri, Nisha; Cordeiro, Peter G; Keam, Jennifer; Ballangrud, Ase; Shi, Weiji; Zhang, Zhigang; Nerbun, Claire T; Woch, Katherine M; Stein, Nicholas F; Zhou, Ying; McCormick, Beryl; Powell, Simon N; Ho, Alice Y
2012-10-01
To assess the impact of immediate breast reconstruction on postmastectomy radiation (PMRT) using dose-volume histogram (DVH) data. Two hundred forty-seven women underwent PMRT at our center, 196 with implant reconstruction and 51 without reconstruction. Patients with reconstruction were treated with tangential photons, and patients without reconstruction were treated with en-face electron fields and customized bolus. Twenty percent of patients received internal mammary node (IMN) treatment. The DVH data were compared between groups. Ipsilateral lung parameters included V20 (% volume receiving 20 Gy), V40 (% volume receiving 40 Gy), mean dose, and maximum dose. Heart parameters included V25 (% volume receiving 25 Gy), mean dose, and maximum dose. IMN coverage was assessed when applicable. Chest wall coverage was assessed in patients with reconstruction. Propensity-matched analysis adjusted for potential confounders of laterality and IMN treatment. Reconstruction was associated with lower lung V20, mean dose, and maximum dose compared with no reconstruction (all P<.0001). These associations persisted on propensity-matched analysis (all P<.0001). Heart doses were similar between groups (P=NS). Ninety percent of patients with reconstruction had excellent chest wall coverage (D95 >98%). IMN coverage was superior in patients with reconstruction (D95 >92.0 vs 75.7%, P<.001). IMN treatment significantly increased lung and heart parameters in patients with reconstruction (all P<.05) but minimally affected those without reconstruction (all P>.05). Among IMN-treated patients, only lower lung V20 in those without reconstruction persisted (P=.022), and mean and maximum heart doses were higher than in patients without reconstruction (P=.006, P=.015, respectively). Implant reconstruction does not compromise the technical quality of PMRT when the IMNs are untreated. Treatment technique, not reconstruction, is the primary determinant of target coverage and normal tissue doses. Published by Elsevier Inc.
Ridpath, Alison Delano; Scobie, Heather Melissa; Shibeshi, Messeret Eshetu; Yakubu, Ahmadu; Zulu, Flint; Raza, Azhar Abid; Masresha, Balcha; Tohme, Rania
2017-01-01
Despite the availability of effective tetanus prevention strategies, as of 2016, Maternal and Neonatal Tetanus Elimination (MNTE) has not yet been achieved in 18 countries globally. In this paper, we review the status of MNTE in the World Health Organization African Region (AFR),and provide recommendations for achieving and maintaining MNTE in AFR. As of November 2016, 37 (79%) AFR countries have achieved MNTE, with 10 (21%) countries remaining. DTP3 coverage increased from 52% in 2000 to 76% in 2015. In 2015, coverage with at least 2 doses of tetanus containing vaccine (TT2+) and proportion of newborns protected at birth (PAB) were 69% and 77%, compared with 44% and 62% in 2000, respectively. Since 1999, over 79 million women of reproductive age (WRA) have been vaccinated with TT2+ through supplementary immunization activities (SIAs). Despite the progress, only 54% of births were attended by skilled birth attendants (SBAs), 5 (11%) countries provided the 3 WHO-recommended booster doses to both sexes, and about 5.5 million WRA still need to be reached with SIAs. Coverage disparities still exist between countries that have achieved MNTE and those that have not. In 2015, coverage with DTP3 and PAB were higher in MNTE countries compared with those yet to achieve MNTE: 84% vs. 68% and 86% vs. 69%, respectively. Challenges to achieving MNTE in the remaining AFR countries include weak health systems, competing priorities, insufficient funding, insecurity, and sub-optimal neonatal tetanus (NT) surveillance. To achieve and maintain MNTE in AFR, increasing SBAs and tetanus vaccination coverage, integrating tetanus vaccination with other opportunities (e.g., polio and measles campaigns, mother and child health days), and providing appropriately spaced booster doses are needed. Strengthening NT surveillance and conducting serosurveys would ensure appropriate targeting of MNTE activities and high-quality information for validating the achievement and maintenance of elimination.
Ridpath, Alison Delano; Scobie, Heather Melissa; Shibeshi, Messeret Eshetu; Yakubu, Ahmadu; Zulu, Flint; Raza, Azhar Abid; Masresha, Balcha; Tohme, Rania
2017-01-01
Despite the availability of effective tetanus prevention strategies, as of 2016, Maternal and Neonatal Tetanus Elimination (MNTE) has not yet been achieved in 18 countries globally. In this paper, we review the status of MNTE in the World Health Organization African Region (AFR),and provide recommendations for achieving and maintaining MNTE in AFR. As of November 2016, 37 (79%) AFR countries have achieved MNTE, with 10 (21%) countries remaining. DTP3 coverage increased from 52% in 2000 to 76% in 2015. In 2015, coverage with at least 2 doses of tetanus containing vaccine (TT2+) and proportion of newborns protected at birth (PAB) were 69% and 77%, compared with 44% and 62% in 2000, respectively. Since 1999, over 79 million women of reproductive age (WRA) have been vaccinated with TT2+ through supplementary immunization activities (SIAs). Despite the progress, only 54% of births were attended by skilled birth attendants (SBAs), 5 (11%) countries provided the 3 WHO-recommended booster doses to both sexes, and about 5.5 million WRA still need to be reached with SIAs. Coverage disparities still exist between countries that have achieved MNTE and those that have not. In 2015, coverage with DTP3 and PAB were higher in MNTE countries compared with those yet to achieve MNTE: 84% vs. 68% and 86% vs. 69%, respectively. Challenges to achieving MNTE in the remaining AFR countries include weak health systems, competing priorities, insufficient funding, insecurity, and sub-optimal neonatal tetanus (NT) surveillance. To achieve and maintain MNTE in AFR, increasing SBAs and tetanus vaccination coverage, integrating tetanus vaccination with other opportunities (e.g., polio and measles campaigns, mother and child health days), and providing appropriately spaced booster doses are needed. Strengthening NT surveillance and conducting serosurveys would ensure appropriate targeting of MNTE activities and high-quality information for validating the achievement and maintenance of elimination. PMID:29296159
DOE Office of Scientific and Technical Information (OSTI.GOV)
Moriya, S; National Cancer Center, Kashiwa, Chiba; Tachibana, H
Purpose: Daily CT-based three-dimensional image-guided and adaptive (CTIGRT-ART) proton therapy system was designed and developed. We also evaluated the effectiveness of the CTIGRT-ART. Methods: Retrospective analysis was performed in three lung cancer patients: Proton treatment planning was performed using CT image datasets acquired by Toshiba Aquilion ONE. Planning target volume and surrounding organs were contoured by a well-trained radiation oncologist. Dose distribution was optimized using 180-deg. and 270-deg. two fields in passive scattering proton therapy. Well commissioned Simplified Monte Carlo algorithm was used as dose calculation engine. Daily consecutive CT image datasets was acquired by an in-room CT (Toshiba Aquilionmore » LB). In our in-house program, two image registrations for bone and tumor were performed to shift the isocenter using treatment CT image dataset. Subsequently, dose recalculation was performed after the shift of the isocenter. When the dose distribution after the tumor registration exhibits change of dosimetric parameter of CTV D90% compared to the initial plan, an additional process of was performed that the range shifter thickness was optimized. Dose distribution with CTV D90% for the bone registration, the tumor registration only and adaptive plan with the tumor registration was compared to the initial plan. Results: In the bone registration, tumor dose coverage was decreased by 16% on average (Maximum: 56%). The tumor registration shows better coverage than the bone registration, however the coverage was also decreased by 9% (Maximum: 22%) The adaptive plan shows similar dose coverage of the tumor (Average: 2%, Maximum: 7%). Conclusion: There is a high possibility that only image registration for bone and tumor may reduce tumor coverage. Thus, our proposed methodology of image guidance and adaptive planning using the range adaptation after tumor registration would be effective for proton therapy. This research is partially supported by Japan Agency for Medical Research and Development (AMED).« less
Global yellow fever vaccination coverage from 1970 to 2016: an adjusted retrospective analysis.
Shearer, Freya M; Moyes, Catherine L; Pigott, David M; Brady, Oliver J; Marinho, Fatima; Deshpande, Aniruddha; Longbottom, Joshua; Browne, Annie J; Kraemer, Moritz U G; O'Reilly, Kathleen M; Hombach, Joachim; Yactayo, Sergio; de Araújo, Valdelaine E M; da Nóbrega, Aglaêr A; Mosser, Jonathan F; Stanaway, Jeffrey D; Lim, Stephen S; Hay, Simon I; Golding, Nick; Reiner, Robert C
2017-11-01
Substantial outbreaks of yellow fever in Angola and Brazil in the past 2 years, combined with global shortages in vaccine stockpiles, highlight a pressing need to assess present control strategies. The aims of this study were to estimate global yellow fever vaccination coverage from 1970 through to 2016 at high spatial resolution and to calculate the number of individuals still requiring vaccination to reach population coverage thresholds for outbreak prevention. For this adjusted retrospective analysis, we compiled data from a range of sources (eg, WHO reports and health-service-provider registeries) reporting on yellow fever vaccination activities between May 1, 1939, and Oct 29, 2016. To account for uncertainty in how vaccine campaigns were targeted, we calculated three population coverage values to encompass alternative scenarios. We combined these data with demographic information and tracked vaccination coverage through time to estimate the proportion of the population who had ever received a yellow fever vaccine for each second level administrative division across countries at risk of yellow fever virus transmission from 1970 to 2016. Overall, substantial increases in vaccine coverage have occurred since 1970, but notable gaps still exist in contemporary coverage within yellow fever risk zones. We estimate that between 393·7 million and 472·9 million people still require vaccination in areas at risk of yellow fever virus transmission to achieve the 80% population coverage threshold recommended by WHO; this represents between 43% and 52% of the population within yellow fever risk zones, compared with between 66% and 76% of the population who would have required vaccination in 1970. Our results highlight important gaps in yellow fever vaccination coverage, can contribute to improved quantification of outbreak risk, and help to guide planning of future vaccination efforts and emergency stockpiling. The Rhodes Trust, Bill & Melinda Gates Foundation, the Wellcome Trust, the National Library of Medicine of the National Institutes of Health, the European Union's Horizon 2020 research and innovation programme. Copyright © 2017 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 license. Published by Elsevier Ltd.. All rights reserved.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Fattori, G; Klimpki, G; Safai, S
Purpose: We aim to compare the performance of discrete spot- or continuous line scanning combined with rescanning in mitigating residual organ motion during gated proton therapy treatments. Methods: The Quasar respiratory phantom was used to move a 2D scintillation detector on a linear trajectory with sinusoidal motion pattern (sin{sup 4}), 20 mm peak-to-peak amplitude and 5 sec period. Its motion was monitored using a customized solution based on optical tracking technology. We compared spot and line scanning plans for a monoenergetic 150 MeV circular field, 50.4 mm radius at isocenter. Transverse dose distributions at 13 cm depth in PMMA (15.47more » mm water equivalent) were measured to compare three options for motion mitigation: rescanning (10× factor), gating and their combination. The gating window was centered in the trajectory plateau to simulate end-exhale gated treatment in presence of 2 mm and 4 mm residual motion, parallel or perpendicular to the primary scanning direction. Results: When the target moves perpendicular to the primary scanning direction, large dose deviations are measured (γ3%/3mm=47%) without mitigation techniques. Beam gating combined with rescanning restores target coverage (γ3%/3mm=91%). For parallel target motion, observed dose distortions in the non-compensated irradiation are smaller (γ3%/3mm=77%). Beam gating alone recovers the 100% gamma pass-rate at 3%/3mm. Continuous line scanning reduces delivery time by up to 60% with respect to discrete spot scanning in presence of motion mitigation, and improves homogeneity when rescanning is applied (up to 20%, perpendicular motion, 4 mm residual motion). Conclusion: The direction of motion has a large impact on the target dose coverage. Nevertheless, even in the worst case scenario, gating combined with rescanning could mitigate the impact of motion on dose deposition. Moreover, continuous line rescanning improves the robustness against residual motion in the gating window. This study has received funding from the European Community’s Seventh Framework Programme (FP7/2007–2013) under grant agreement n.290605 (PSI-FELLOW/COFUND) and ‘Giuliana and Giorgio Stefanini Foundation’.« less
Evaluation of the measles, mumps and rubella vaccination catch-up campaign in England in 2013.
Simone, Benedetto; Balasegaram, Sooria; Gobin, Maya; Anderson, Charlotte; Charlett, André; Coole, Louise; Maguire, Helen; Nichols, Tom; Rawlings, Chas; Ramsay, Mary; Oliver, Isabel
2014-08-06
In January-March 2013 in England, confirmed measles cases increased in children aged 10-16 years. In April-September 2013, the National Health System and Public Health England launched a national measles-mumps-rubella (MMR) campaign based on data from Child Health Information Systems (CHIS) estimating that approximately 8% in this age group were unvaccinated. We estimated coverage at baseline, and, of those unvaccinated (target), the proportion vaccinated up to 20/08/2013 (mid-point) to inform further public health action. We selected a sample of 6644 children aged 10-16 years using multistage sampling from those reported unvaccinated in CHIS at baseline and validated their records against GP records. We adjusted the CHIS MMR vaccine coverage estimates correcting by the proportion of vaccinated children obtained through sample validation. We validated 5179/6644 (78%) of the sample records. Coverage at baseline was estimated as 94.7% (95% confidence intervals, CI: 93.5-96.0%), lower in London (86.9%, 95%CI: 83.0-90.9%) than outside (96.1%, 95%CI 95.5-96.8%). The campaign reached 10.8% (95%CI: 7.0-14.6%) of the target population, lower in London (7.1%, 95%CI: 4.9-9.3) than in the rest of England (11.4%, 95%CI: 7.0-15.9%). Coverage increased by 0.5% up to 95.3% (95% CI: 94.1-96.4%) but an estimated 210,000 10-16 year old children remained unvaccinated nationally. Baseline MMR coverage was higher than previously reported and was estimated to have reached the 95% campaign objective at midpoint. Eleven per cent of the target population were vaccinated during the campaign, and may be underestimated, especially in London. No further national campaigns are needed but targeted local vaccination activities should be considered. Copyright © 2014 Elsevier Ltd. All rights reserved.
Gao, Shuqin; Pan, Xu; Cui, Qingguo; Hu, Yukun; Ye, Xuehua; Dong, Ming
2014-01-01
Plant interactions greatly affect plant community structure. Dryland ecosystems are characterized by low amounts of unpredictable precipitation as well as by often having biological soil crusts (BSCs) on the soil surface. In dryland plant communities, plants interact mostly as they compete for water resources, and the direction and intensity of plant interaction varies as a function of the temporal fluctuation in water availability. Since BSCs influence water redistribution to some extent, a greenhouse experiment was conducted to test the hypothesis that the intensity and direction of plant interactions in a dryland plant community can be modified by BSCs. In the experiment, 14 combinations of four plant species (Artemisia ordosica, Artemisia sphaerocephala, Chloris virgata and Setaria viridis) were subjected to three levels of coverage of BSCs and three levels of water supply. The results show that: 1) BSCs affected plant interaction intensity for the four plant species: a 100% coverage of BSCs significantly reduced the intensity of competition between neighboring plants, while it was highest with a 50% coverage of BSCs in combination with the target species of A. sphaerocephala and C. virgata; 2) effects of the coverage of BSCs on plant interactions were modified by water regime when the target species were C. virgata and S. viridis; 3) plant interactions were species-specific. In conclusion, the percent coverage of BSCs affected plant interactions, and the effects were species-specific and could be modified by water regimes. Further studies should focus on effects of the coverage of BSCs on plant-soil hydrological processes. PMID:24498173
Gao, Shuqin; Pan, Xu; Cui, Qingguo; Hu, Yukun; Ye, Xuehua; Dong, Ming
2014-01-01
Plant interactions greatly affect plant community structure. Dryland ecosystems are characterized by low amounts of unpredictable precipitation as well as by often having biological soil crusts (BSCs) on the soil surface. In dryland plant communities, plants interact mostly as they compete for water resources, and the direction and intensity of plant interaction varies as a function of the temporal fluctuation in water availability. Since BSCs influence water redistribution to some extent, a greenhouse experiment was conducted to test the hypothesis that the intensity and direction of plant interactions in a dryland plant community can be modified by BSCs. In the experiment, 14 combinations of four plant species (Artemisia ordosica, Artemisia sphaerocephala, Chloris virgata and Setaria viridis) were subjected to three levels of coverage of BSCs and three levels of water supply. The results show that: 1) BSCs affected plant interaction intensity for the four plant species: a 100% coverage of BSCs significantly reduced the intensity of competition between neighboring plants, while it was highest with a 50% coverage of BSCs in combination with the target species of A. sphaerocephala and C. virgata; 2) effects of the coverage of BSCs on plant interactions were modified by water regime when the target species were C. virgata and S. viridis; 3) plant interactions were species-specific. In conclusion, the percent coverage of BSCs affected plant interactions, and the effects were species-specific and could be modified by water regimes. Further studies should focus on effects of the coverage of BSCs on plant-soil hydrological processes.
Maina, Isabella; Wanjala, Pepela; Soti, David; Kipruto, Hillary; Droti, Benson; Boerma, Ties
2017-10-01
To develop a systematic approach to obtain the best possible national and subnational statistics for maternal and child health coverage indicators from routine health-facility data. Our approach aimed to obtain improved numerators and denominators for calculating coverage at the subnational level from health-facility data. This involved assessing data quality and determining adjustment factors for incomplete reporting by facilities, then estimating local target populations based on interventions with near-universal coverage (first antenatal visit and first dose of pentavalent vaccine). We applied the method to Kenya at the county level, where routine electronic reporting by facilities is in place via the district health information software system. Reporting completeness for facility data were well above 80% in all 47 counties and the consistency of data over time was good. Coverage of the first dose of pentavalent vaccine, adjusted for facility reporting completeness, was used to obtain estimates of the county target populations for maternal and child health indicators. The country and national statistics for the four-year period 2012/13 to 2015/16 showed good consistency with results of the 2014 Kenya demographic and health survey. Our results indicated a stagnation of immunization coverage in almost all counties, a rapid increase of facility-based deliveries and caesarean sections and limited progress in antenatal care coverage. While surveys will continue to be necessary to provide population-based data, web-based information systems for health facility reporting provide an opportunity for more frequent, local monitoring of progress, in maternal and child health.
A Target Coverage Scheduling Scheme Based on Genetic Algorithms in Directional Sensor Networks
Gil, Joon-Min; Han, Youn-Hee
2011-01-01
As a promising tool for monitoring the physical world, directional sensor networks (DSNs) consisting of a large number of directional sensors are attracting increasing attention. As directional sensors in DSNs have limited battery power and restricted angles of sensing range, maximizing the network lifetime while monitoring all the targets in a given area remains a challenge. A major technique to conserve the energy of directional sensors is to use a node wake-up scheduling protocol by which some sensors remain active to provide sensing services, while the others are inactive to conserve their energy. In this paper, we first address a Maximum Set Covers for DSNs (MSCD) problem, which is known to be NP-complete, and present a greedy algorithm-based target coverage scheduling scheme that can solve this problem by heuristics. This scheme is used as a baseline for comparison. We then propose a target coverage scheduling scheme based on a genetic algorithm that can find the optimal cover sets to extend the network lifetime while monitoring all targets by the evolutionary global search technique. To verify and evaluate these schemes, we conducted simulations and showed that the schemes can contribute to extending the network lifetime. Simulation results indicated that the genetic algorithm-based scheduling scheme had better performance than the greedy algorithm-based scheme in terms of maximizing network lifetime. PMID:22319387
Burnum-Johnson, Kristin E.; Nie, Song; Casey, Cameron P.; Monroe, Matthew E.; Orton, Daniel J.; Ibrahim, Yehia M.; Gritsenko, Marina A.; Clauss, Therese R. W.; Shukla, Anil K.; Moore, Ronald J.; Purvine, Samuel O.; Shi, Tujin; Qian, Weijun; Liu, Tao; Baker, Erin S.; Smith, Richard D.
2016-01-01
Current proteomic approaches include both broad discovery measurements and quantitative targeted analyses. In many cases, discovery measurements are initially used to identify potentially important proteins (e.g. candidate biomarkers) and then targeted studies are employed to quantify a limited number of selected proteins. Both approaches, however, suffer from limitations. Discovery measurements aim to sample the whole proteome but have lower sensitivity, accuracy, and quantitation precision than targeted approaches, whereas targeted measurements are significantly more sensitive but only sample a limited portion of the proteome. Herein, we describe a new approach that performs both discovery and targeted monitoring (DTM) in a single analysis by combining liquid chromatography, ion mobility spectrometry and mass spectrometry (LC-IMS-MS). In DTM, heavy labeled target peptides are spiked into tryptic digests and both the labeled and unlabeled peptides are detected using LC-IMS-MS instrumentation. Compared with the broad LC-MS discovery measurements, DTM yields greater peptide/protein coverage and detects lower abundance species. DTM also achieved detection limits similar to selected reaction monitoring (SRM) indicating its potential for combined high quality discovery and targeted analyses, which is a significant step toward the convergence of discovery and targeted approaches. PMID:27670688
Actionable mutations in canine hemangiosarcoma
Wang, Guannan; Wu, Ming; Maloneyhuss, Martha A.; Wojcik, John; Durham, Amy C.; Mason, Nicola J.
2017-01-01
Background Angiosarcomas (AS) are rare in humans, but they are a deadly subtype of soft tissue sarcoma. Discovery sequencing in AS, especially the visceral form, is hampered by the rarity of cases. Most diagnostic material exists as archival formalin fixed, paraffin embedded tissue which serves as a poor source of high quality DNA for genome-wide sequencing. We approached this problem through comparative genomics. We hypothesized that exome sequencing a histologically similar tumor, hemangiosarcoma (HSA), that occurs in approximately 50,000 dogs per year, may lead to the identification of potential oncogenic drivers and druggable targets that could also occur in angiosarcoma. Methods Splenic hemangiosarcomas are common in dogs, which allowed us to collect a cohort of archived matched tumor and normal tissue samples suitable for whole exome sequencing. Mapping of the reads to the latest canine reference genome (Canfam3) demonstrated that >99% of the targeted exomal regions were covered, with >80% at 20X coverage and >90% at 10X coverage. Results and conclusions Sequence analysis of 20 samples identified somatic mutations in PIK3CA, TP53, PTEN, and PLCG1, all of which correspond to well-known tumor drivers in human cancer, in more than half of the cases. In one case, we identified a mutation in PLCG1 identical to a mutation observed previously in this gene in human visceral AS. Activating PIK3CA mutations present novel therapeutic targets, and clinical trials of targeted inhibitors are underway in human cancers. Our results lay a foundation for similar clinical trials in canine HSA, enabling a precision medicine approach to this disease. PMID:29190660
Actionable mutations in canine hemangiosarcoma.
Wang, Guannan; Wu, Ming; Maloneyhuss, Martha A; Wojcik, John; Durham, Amy C; Mason, Nicola J; Roth, David B
2017-01-01
Angiosarcomas (AS) are rare in humans, but they are a deadly subtype of soft tissue sarcoma. Discovery sequencing in AS, especially the visceral form, is hampered by the rarity of cases. Most diagnostic material exists as archival formalin fixed, paraffin embedded tissue which serves as a poor source of high quality DNA for genome-wide sequencing. We approached this problem through comparative genomics. We hypothesized that exome sequencing a histologically similar tumor, hemangiosarcoma (HSA), that occurs in approximately 50,000 dogs per year, may lead to the identification of potential oncogenic drivers and druggable targets that could also occur in angiosarcoma. Splenic hemangiosarcomas are common in dogs, which allowed us to collect a cohort of archived matched tumor and normal tissue samples suitable for whole exome sequencing. Mapping of the reads to the latest canine reference genome (Canfam3) demonstrated that >99% of the targeted exomal regions were covered, with >80% at 20X coverage and >90% at 10X coverage. Sequence analysis of 20 samples identified somatic mutations in PIK3CA, TP53, PTEN, and PLCG1, all of which correspond to well-known tumor drivers in human cancer, in more than half of the cases. In one case, we identified a mutation in PLCG1 identical to a mutation observed previously in this gene in human visceral AS. Activating PIK3CA mutations present novel therapeutic targets, and clinical trials of targeted inhibitors are underway in human cancers. Our results lay a foundation for similar clinical trials in canine HSA, enabling a precision medicine approach to this disease.
CCTV Coverage Index Based on Surveillance Resolution and Its Evaluation Using 3D Spatial Analysis
Choi, Kyoungah; Lee, Impyeong
2015-01-01
We propose a novel approach to evaluating how effectively a closed circuit television (CCTV) system can monitor a targeted area. With 3D models of the target area and the camera parameters of the CCTV system, the approach produces surveillance coverage index, which is newly defined in this study as a quantitative measure for surveillance performance. This index indicates the proportion of the space being monitored with a sufficient resolution to the entire space of the target area. It is determined by computing surveillance resolution at every position and orientation, which indicates how closely a specific object can be monitored with a CCTV system. We present full mathematical derivation for the resolution, which depends on the location and orientation of the object as well as the geometric model of a camera. With the proposed approach, we quantitatively evaluated the surveillance coverage of a CCTV system in an underground parking area. Our evaluation process provided various quantitative-analysis results, compelling us to examine the design of the CCTV system prior to its installation and understand the surveillance capability of an existing CCTV system. PMID:26389909
Douglas, Gillian; Van Kampen, Erik; Hale, Ashley B; McNeill, Eileen; Patel, Jyoti; Crabtree, Mark J; Ali, Ziad; Hoerr, Robert A; Alp, Nicholas J; Channon, Keith M
2013-11-01
Understanding endothelial cell repopulation post-stenting and how this modulates in-stent restenosis is critical to improving arterial healing post-stenting. We used a novel murine stent model to investigate endothelial cell repopulation post-stenting, comparing the response of drug-eluting stents with a primary genetic modification to improve endothelial cell function. Endothelial cell repopulation was assessed en face in stented arteries in ApoE(-/-) mice with endothelial-specific LacZ expression. Stent deployment resulted in near-complete denudation of endothelium, but was followed by endothelial cell repopulation, by cells originating from both bone marrow-derived endothelial progenitor cells and from the adjacent vasculature. Paclitaxel-eluting stents reduced neointima formation (0.423 ± 0.065 vs. 0.240 ± 0.040 mm(2), P = 0.038), but decreased endothelial cell repopulation (238 ± 17 vs. 154 ± 22 nuclei/mm(2), P = 0.018), despite complete strut coverage. To test the effects of selectively improving endothelial cell function, we used transgenic mice with endothelial-specific overexpression of GTP-cyclohydrolase 1 (GCH-Tg) as a model of enhanced endothelial cell function and increased NO production. GCH-Tg ApoE(-/-) mice had less neointima formation compared with ApoE(-/-) littermates (0.52 ± 0.08 vs. 0.26 ± 0.09 mm(2), P = 0.039). In contrast to paclitaxel-eluting stents, reduced neointima formation in GCH-Tg mice was accompanied by increased endothelial cell coverage (156 ± 17 vs. 209 ± 23 nuclei/mm(2), P = 0.043). Drug-eluting stents reduce not only neointima formation but also endothelial cell repopulation, independent of strut coverage. In contrast, selective targeting of endothelial cell function is sufficient to improve endothelial cell repopulation and reduce neointima formation. Targeting endothelial cell function is a rational therapeutic strategy to improve vascular healing and decrease neointima formation after stenting.
Abuodeh, Yazan; Naghavi, Arash O; Echevarria, Michelle; DeMarco, MaryLou; Tonner, Brian; Feygelman, Vladimir; Stevens, Craig W; Perez, Bradford A; Dilling, Thomas J
2018-01-01
A previous meta-analysis (MA) found postoperative radiotherapy (PORT) in lung cancer patients to be detrimental in N0/N1 patients and equivocal in the N2 setting. We hypothesized that treatment plans generated using MA protocols had worse dosimetric outcomes compared to modern plans. We retrieved plans for 13 patients who received PORT with modern planning. A plan was recreated for each patient using the 8 protocols included in MA. Dosimetric values were then compared between the modern and simulated MA plans. A total of 104 MA plans were generated. Median prescribed dose was 50.4 (range, 50-60) Gy in the modern plans and 53.2 (30-60) Gy in the MA protocols. Median planning volume coverage was 96% (93%-100%) in the modern plans, versus 58% (0%-100%) in the MA plans (P < .001). Internal target volume coverage was 100% (99%-100%) versus 65% (0%-100%), respectively (P < .001). Organs at risk received the following doses: spinal cord maximum dose, 36.8 (4.6-50.4) Gy versus 46.8 (2.9-74.0) Gy (P < .001); esophageal mean dose, 22.9 (5.5-35) Gy versus 30.5 (11.1-52.5) Gy (P = .003); heart V30 (percentage of volume of an organ receiving at least a dose of 30 Gy), 16% (0%-45%) versus 35% (0%-79%) (P = .047); mean lung dose, 12.4 (3.4-24.3) Gy versus 14.8 (4.1-27.4) Gy (P = .008); and lung V20, 18% (4%-34%) versus 25% (8%-67%) (P = .023). We quantitatively confirm the inferiority of the techniques used in the PORT MA. Our analysis showed a lower therapeutic ratio in the MA plans, which may explain the poor outcomes in the MA. The findings of the MA are not relevant in the era of modern treatment planning. Copyright © 2017 Elsevier Inc. All rights reserved.
2007-02-01
bladder and the rectum are overprotected while the PTV coverage is undesirably reduced. On the other hand, if their maximum dose is increased and/or...B, the bladder and rectum were overprotected with undesirably low PTV coverage (84.54%). The reduction of their weighting factor increased PTV
Ferrinho, Paulo; Dramé, Mohamed; Biai, Sidu; Lopes, Orlando; Sousa, Fernando de; Van Lerberghe, Wim
2013-01-01
Although many countries have improved vaccination coverage in recent years, some, including Guinea-Bissau, failed to meet expected targets. This paper tries to understand the main barriers to better vaccination coverage in the context of the GAVI-Alliance (The Global Alliance for Vaccines and Immunisation) cash-based support provided to Guinea-Bissau. The analysis is based on a document analysis and a three round Delphi study with a final consensus meeting. Consensus attributed about 25% of the failure to perform better to implementation problems; and about 10% to governance and also 10% to scarce resources. The qualitative analysis validates the importance of implementation issues and upgraded the relevance of the human resources crisis as an important drawback. The recommendations were balanced in their upstream-downstream focus but were blind to health information issues and logistical difficulties. It is commendable that such a fragile state, with all sorts of barriers, manages to sustain a slow steady growth of its vaccination coverage. Not reaching the targets set reflects the inappropriateness of those targets rather than a lack of commitment of the health workforce. In the unstable context of countries such as Guinea-Bissau, the predictability of the funds from global health initiatives like the GAVI-Alliance seem to make all the difference in achieving small consistent health gains even in the presence of other major bottlenecks.
Engaging Communities With a Simple Tool to Help Increase Immunization Coverage
Jain, Manish; Taneja, Gunjan; Amin, Ruhul; Steinglass, Robert; Favin, Michael
2015-01-01
ABSTRACT The level of vaccination coverage in a given community depends on both service factors and the degree to which the public understands and trusts the immunization process. This article describes an approach that aims to raise awareness and boost demand. Developed in India, the “My Village Is My Home” (MVMH) tool, known as Uma Imunizasaun (UI) in Timor-Leste, is a poster-sized material used by volunteers and health workers to record the births and vaccination dates of every infant in a community. Introduction of the tool in 5 districts of India (April 2012 to March 2013) and in 7 initial villages in Timor-Leste (beginning in January 2012) allowed community leaders, volunteers, and health workers to monitor the vaccination status of every young child and guided reminder and motivational visits. In 3 districts of India, we analyzed data on vaccination coverage and timeliness before and during use of the tool; in 2 other districts, analysis was based only on data for new births during use of the tool. In Timor-Leste, we compared UI data from the 3 villages with the most complete data with data for the same villages from the vaccination registers from the previous year. In both countries, we also obtained qualitative data about perceptions of the tool through interviews with health workers and community members. Assessments in both countries found evidence suggesting improved vaccination timeliness and coverage. In India, pilot communities had 80% or higher coverage of identified and eligible children for all vaccines. In comparison, overall coverage in the respective districts during the same time period was much lower, at 49% to 69%. In Timor-Leste, both the number of infants identified and immunized rose substantially with use of the tool compared with the previous year (236 vs. 155, respectively, identified as targets; 185 vs. 147, respectively, received Penta 3). Although data challenges limit firm conclusions, the experiences in both countries suggest that “My Village Is My Home” is a promising tool that has the potential to broaden program coverage by marshalling both community residents and health workers to track individual children's vaccinations. Three states in India have adopted the tool, and Timor-Leste had also planned to scale-up the initiative. PMID:25745125
Stuckey, Erin M; Miller, John M; Littrell, Megan; Chitnis, Nakul; Steketee, Rick
2016-03-09
Malaria elimination requires reducing both the potential of mosquitoes to transmit parasites to humans and humans to transmit parasites to mosquitoes. To achieve this goal in Southern province, Zambia a mass test and treat (MTAT) campaign was conducted from 2011-2013 to complement high coverage of long-lasting insecticide-treated nets (LLIN). To identify factors likely to increase campaign effectiveness, a modelling approach was applied to investigate the simulated effect of alternative operational strategies for parasite clearance in southern province. OpenMalaria, a discrete-time, individual-based stochastic model of malaria, was parameterized for the study area to simulate anti-malarial drug administration for interruption of transmission. Simulations were run for scenarios with a range of artemisinin-combination therapies, proportion of the population reached by the campaign, targeted age groups, time between campaign rounds, Plasmodium falciparum test protocols, and the addition of drugs aimed at preventing onward transmission. A sensitivity analysis was conducted to assess uncertainty of simulation results. Scenarios were evaluated based on the reduction in all-age parasite prevalence during the peak transmission month one year following the campaign, compared to the currently-implemented strategy of MTAT 19 % population coverage at pilot and 40 % coverage during the first year of implementation in the presence of 56 % LLIN use and 18 % indoor residual spray coverage. Simulation results suggest the most important determinant of success in reducing prevalence is the population coverage achieved in the campaign, which would require more than 1 year of campaign implementation for elimination. The inclusion of single low-dose primaquine, which acts as a gametocytocide, or ivermectin, which acts as an endectocide, to the drug regimen did not further reduce parasite prevalence one year following the campaign compared to the currently-implemented strategy. Simulation results indicate a high proportion of low-density infections were missed by rapid diagnostic tests that would be treated and cleared with mass drug administration (MDA). The optimal implementation strategy for MTAT or MDA will vary by background level of prevalence, by rate of infections imported to the area, and by ability to operationally achieve high population coverage. Overall success with new parasite clearance strategies depends on continued coverage of vector control interventions to ensure sustained gains in reduction of disease burden.
Experiment of constraining symmetry energy at supra-saturation density with π-/π+ at HIRFL-CSR
NASA Astrophysics Data System (ADS)
Zhang, Ming; Xiao, Zhi-Gang; Zhu, Sheng-Jiang
2010-08-01
The possibility of the experiment for constraining the symmetry energy Esym(ρ) at supra-densities via π-/π+ probe on the external target experiment of phase I (ETE(I)) with part coverage at forward angle at HIRFL-CSR is studied for the first time by using the isospin and momentum dependent hadronic transport model IBUU04. Based on the transport simulation with Au+Au collisions at 400 MeV/u, it is found that the differential π-/π+ ratios are more sensitive to Esym(ρ) at forward angles in laboratory reference, compared with the total yield ratio widely proposed. The insufficient coverage at lower transverse momentum maintains the sensitivity of the dependence of π-/π+ ratio on the Esym(ρ) at high density, indicating that the ETF (I) under construction in Lanzhou provides the possibility of performing the experiment for probing the asymmetric nuclear equation of state.
Ward, Charlotte; Byrne, Lisa; White, Joanne M; Amirthalingam, Gayatri; Tiley, Karen; Edelstein, Michael
2017-04-25
In September 2013, England introduced a shingles vaccination programme to reduce incidence and severity of shingles in the elderly. This study aims to assess variation in vaccine coverage with regards to selected sociodemographic factors to inform activities for improving equity of the programme. Eligible 70year-olds were identified from a national vaccine coverage dataset in 2014/15 that includes 95% of GPs in England. NHS England Local Team (LT) and index of multiple deprivation (IMD) scores were assigned to patients based on GP-postcode. Vaccine coverage (%) with 95% confidence intervals (CIs), were calculated overall and by LT, ethnicity and IMD, using binomial regression. Of 502,058 eligible adults, 178,808 (35.6%) had ethnicity recorded. Crude vaccine coverage was 59.5% (95%CI: 59.3-59.7). Coverage was lowest in London (49.6% coverage, 95%CI: 49.0-50.2), and compared to this coverage was significantly higher in all other LTs (+6.3 to +10.4, p<0.001) after adjusting for ethnicity and IMD. Coverage decreased with increasing deprivation and was 8.2% lower in the most deprived (95%CI: 7.3-9.1) compared with the least deprived IMD quintile (64.1% coverage, 95%CI: 63.6-64.6), after adjustment for ethnicity and LT. Compared with White-British (60.7% coverage, 95%CI: 60.5-61.0), other ethnic groups had between 4.0% (Indian) and 21.8% (Mixed: White and Black African) lower coverage. After adjusting for IMD and LT, significantly lower coverage by ethnicity persisted in all groups, except in Mixed: Other, Indian and Bangladeshi compared with White-British. After taking geography and deprivation into account, shingles vaccine coverage varied by ethnicity. White-British, Indian and Bangladeshi groups had highest coverage; Mixed: White and Black African, and Black-other ethnicities had the lowest. Patients' ethnicity and IMD are predictors of coverage which contribute to, but do not wholly account for, geographical variation coverage. Interventions to address service-related, sociodemographic and ethnic inequalities in shingles vaccine coverage are required. Copyright © 2017 Elsevier Ltd. All rights reserved.
Protecting Important Sites for Biodiversity Contributes to Meeting Global Conservation Targets
Butchart, Stuart H. M.; Scharlemann, Jörn P. W.; Evans, Mike I.; Quader, Suhel; Aricò, Salvatore; Arinaitwe, Julius; Balman, Mark; Bennun, Leon A.; Bertzky, Bastian; Besançon, Charles; Boucher, Timothy M.; Brooks, Thomas M.; Burfield, Ian J.; Burgess, Neil D.; Chan, Simba; Clay, Rob P.; Crosby, Mike J.; Davidson, Nicholas C.; De Silva, Naamal; Devenish, Christian; Dutson, Guy C. L.; Fernández, David F. Día z; Fishpool, Lincoln D. C.; Fitzgerald, Claire; Foster, Matt; Heath, Melanie F.; Hockings, Marc; Hoffmann, Michael; Knox, David; Larsen, Frank W.; Lamoreux, John F.; Loucks, Colby; May, Ian; Millett, James; Molloy, Dominic; Morling, Paul; Parr, Mike; Ricketts, Taylor H.; Seddon, Nathalie; Skolnik, Benjamin; Stuart, Simon N.; Upgren, Amy; Woodley, Stephen
2012-01-01
Protected areas (PAs) are a cornerstone of conservation efforts and now cover nearly 13% of the world's land surface, with the world's governments committed to expand this to 17%. However, as biodiversity continues to decline, the effectiveness of PAs in reducing the extinction risk of species remains largely untested. We analyzed PA coverage and trends in species' extinction risk at globally significant sites for conserving birds (10,993 Important Bird Areas, IBAs) and highly threatened vertebrates and conifers (588 Alliance for Zero Extinction sites, AZEs) (referred to collectively hereafter as ‘important sites’). Species occurring in important sites with greater PA coverage experienced smaller increases in extinction risk over recent decades: the increase was half as large for bird species with>50% of the IBAs at which they occur completely covered by PAs, and a third lower for birds, mammals and amphibians restricted to protected AZEs (compared with unprotected or partially protected sites). Globally, half of the important sites for biodiversity conservation remain unprotected (49% of IBAs, 51% of AZEs). While PA coverage of important sites has increased over time, the proportion of PA area covering important sites, as opposed to less important land, has declined (by 0.45–1.14% annually since 1950 for IBAs and 0.79–1.49% annually for AZEs). Thus, while appropriately located PAs may slow the rate at which species are driven towards extinction, recent PA network expansion has under-represented important sites. We conclude that better targeted expansion of PA networks would help to improve biodiversity trends. PMID:22457717
Imran, Hafsa; Raja, Dania; Grassly, Nicholas C; Wadood, M Zubair; Safdar, Rana M; O'Reilly, Kathleen M
2018-03-01
Within Pakistan, estimates of vaccination coverage with the pentavalent vaccine, oral polio vaccine (OPV) and measles vaccine (MV) in 2011 were reported to be 74%, 75% and 53%, respectively. These national estimates may mask regional variation. The reasons for this variation have not been explored. Data from the Multiple Indicator Cluster Surveys (MICS) for Balochistan and Punjab (2010-2011) are analysed to examine factors associated with receiving three or more doses of the pentavalent vaccine and one or more MVs using regression modelling. Pentavalent and OPV estimates from the MICS were compared to vaccine dose histories from surveillance for acute flaccid paralysis (AFP; poliomyelitis) to ascertain agreement. Adjusted coverage of children 12-23 months of age were estimated to be 16.0%, 75.5% and 34.2% in Balochistan and 58.0%, 87.7% and 72.6% in Punjab for the pentavalent vaccine, OPV and MV, respectively. Maternal education, healthcare utilization and wealth were associated with receiving the pentavalent vaccine and the MV. There was a strong correlation of district estimates of vaccination coverage between AFP and MICS data, but AFP estimates of pentavalent coverage in Punjab were biased toward higher values. National estimates mask variation and estimates from individual surveys should be considered alongside other estimates. The development of strategies targeted towards poorly educated parents within low-wealth quintiles that may not typically access healthcare could improve vaccination rates.
Designing Cash Transfer Programs for an Older Population: The Mexican Case
Kapteyn, Arie; Tassot, Caroline
2016-01-01
Aging populations and the prevalence of poverty in old age have led to the introduction of noncontributory pensions in many countries. We consider a number of alternative targeting approaches and simulate their effects in an empirical application in the State of Yucatan, Mexico. We compare the approaches with respect to leakage, under-coverage, and their effects on government budgets. We are also able to compare the simulated effects of one alternative with the observed effect of a recently introduced demogrant and find that the simulation is a close approximation of the empirical outcomes. We discuss issues of implementation and political feasibility. PMID:28752042
Van Vlaenderen, Ilse; Van Bellinghen, Laure-Anne; Meier, Genevieve; Nautrup, Barbara Poulsen
2013-01-22
Indirect herd effect from vaccination of children offers potential for improving the effectiveness of influenza prevention in the remaining unvaccinated population. Static models used in cost-effectiveness analyses cannot dynamically capture herd effects. The objective of this study was to develop a methodology to allow herd effect associated with vaccinating children against seasonal influenza to be incorporated into static models evaluating the cost-effectiveness of influenza vaccination. Two previously published linear equations for approximation of herd effects in general were compared with the results of a structured literature review undertaken using PubMed searches to identify data on herd effects specific to influenza vaccination. A linear function was fitted to point estimates from the literature using the sum of squared residuals. The literature review identified 21 publications on 20 studies for inclusion. Six studies provided data on a mathematical relationship between effective vaccine coverage in subgroups and reduction of influenza infection in a larger unvaccinated population. These supported a linear relationship when effective vaccine coverage in a subgroup population was between 20% and 80%. Three studies evaluating herd effect at a community level, specifically induced by vaccinating children, provided point estimates for fitting linear equations. The fitted linear equation for herd protection in the target population for vaccination (children) was slightly less conservative than a previously published equation for herd effects in general. The fitted linear equation for herd protection in the non-target population was considerably less conservative than the previously published equation. This method of approximating herd effect requires simple adjustments to the annual baseline risk of influenza in static models: (1) for the age group targeted by the childhood vaccination strategy (i.e. children); and (2) for other age groups not targeted (e.g. adults and/or elderly). Two approximations provide a linear relationship between effective coverage and reduction in the risk of infection. The first is a conservative approximation, recommended as a base-case for cost-effectiveness evaluations. The second, fitted to data extracted from a structured literature review, provides a less conservative estimate of herd effect, recommended for sensitivity analyses.
The rationale for intensity-modulated proton therapy in geometrically challenging cases
NASA Astrophysics Data System (ADS)
Safai, S.; Trofimov, A.; Adams, J. A.; Engelsman, M.; Bortfeld, T.
2013-09-01
Intensity-modulated proton therapy (IMPT) delivered with beam scanning is currently available at a limited number of proton centers. However, a simplified form of IMPT, the technique of field ‘patching’, has long been a standard practice in proton therapy centers. In field patching, different parts of the target volume are treated from different directions, i.e., a part of the tumor gets either full dose from a radiation field, or almost no dose. Thus, patching represents a form of binary intensity modulation. This study explores the limitations of the standard binary field patching technique, and evaluates possible dosimetric advantages of continuous dose modulations in IMPT. Specifics of the beam delivery technology, i.e., pencil beam scanning versus passive scattering and modulation, are not investigated. We have identified two geometries of target volumes and organs at risk (OAR) in which the use of field patching is severely challenged. We focused our investigations on two patient cases that exhibit these geometries: a paraspinal tumor case and a skull-base case. For those cases we performed treatment planning comparisons of three-dimensional conformal proton therapy (3DCPT) with field patching versus IMPT, using commercial and in-house software, respectively. We also analyzed the robustness of the resulting plans with respect to systematic setup errors of ±1 mm and range errors of ±2.5 mm. IMPT is able to better spare OAR while providing superior dose coverage for the challenging cases identified above. Both 3DCPT and IMPT are sensitive to setup errors and range uncertainties, with IMPT showing the largest effect. Nevertheless, when delivery uncertainties are taken into account IMPT plans remain superior regarding target coverage and OAR sparing. On the other hand, some clinical goals, such as the maximum dose to OAR, are more likely to be unmet with IMPT under large range errors. IMPT can potentially improve target coverage and OAR sparing in challenging cases, even when compared with the relatively complicated and time consuming field patching technique. While IMPT plans tend to be more sensitive to delivery uncertainties, their dosimetric advantage generally holds. Robust treatment planning techniques may further reduce the sensitivity of IMPT plans.
DeHart, Caroline J.; Schweitzer, Mary H.; Thomas, Paul M.; Kelleher, Neil L.
2016-01-01
Proteomic studies of bone require specialized extraction protocols to demineralize and solubilize proteins from within the bone matrix. Although various protocols exist for bone protein recovery, little is known about how discrete steps in each protocol affect the subset of the bone proteome recovered by mass spectrometry (MS) analyses. Characterizing these different “extractomes” will provide critical data for development of novel and more efficient protein extraction methodologies for fossils. Here, we analyze 22 unique sub-extractions of chicken bone and directly compare individual extraction components for their total protein yield and diversity and coverage of bone proteins identified by MS. We extracted proteins using different combinations and ratios of demineralizing reagents, protein-solubilizing reagents, and post-extraction buffer removal methods, then evaluated tryptic digests from 20 µg aliquots of each fraction by tandem MS/MS on a 12T FT-ICR mass spectrometer. We compared total numbers of peptide spectral matches, peptides, and proteins identified from each fraction, the redundancy of protein identifications between discrete steps of extraction methods, and the sequence coverage obtained for select, abundant proteins. Although both alpha chains of collagen I (the most abundant protein in bone) were found in all fractions, other collagenous and non-collagenous proteins (e.g., apolipoprotein, osteonectin, hemoglobin) were differentially identified. We found that when a standardized amount of extracted proteins was analyzed, extraction steps that yielded the most protein (by weight) from bone were often not the ones that produced the greatest diversity of bone proteins, or the highest degree of protein coverage. Generally, the highest degrees of diversity and coverage were obtained from demineralization fractions, and the proteins found in the subsequent solubilization fractions were highly redundant with those in the previous fraction. Based on these data, we identify future directions and parameters to consider (e.g., proteins targeted, amount of sample required) when applying discrete parts of these protocols to fossils. PMID:27812413
Kundrick, Avery; Huang, Zhuojie; Carran, Spencer; Kagoli, Matthew; Grais, Rebecca Freeman; Hurtado, Northan; Ferrari, Matthew
2018-06-15
Despite progress towards increasing global vaccination coverage, measles continues to be one of the leading, preventable causes of death among children worldwide. Whether and how to target sub-national areas for vaccination campaigns continues to remain a question. We analyzed three metrics for prioritizing target areas: vaccination coverage, susceptible birth cohort, and the effective reproductive ratio (R E ) in the context of the 2010 measles epidemic in Malawi. Using case-based surveillance data from the 2010 measles outbreak in Malawi, we estimated vaccination coverage from the proportion of cases reporting with a history of prior vaccination at the district and health facility catchment scale. Health facility catchments were defined as the set of locations closer to a given health facility than to any other. We combined these estimates with regional birth rates to estimate the size of the annual susceptible birth cohort. We also estimated the effective reproductive ratio, R E , at the health facility polygon scale based on the observed rate of exponential increase of the epidemic. We combined these estimates to identify spatial regions that would be of high priority for supplemental vaccination activities. The estimated vaccination coverage across all districts was 84%, but ranged from 61 to 99%. We found that 8 districts and 354 health facility catchments had estimated vaccination coverage below 80%. Areas that had highest birth cohort size were frequently large urban centers that had high vaccination coverage. The estimated R E ranged between 1 and 2.56. The ranking of districts and health facility catchments as priority areas varied depending on the measure used. Each metric for prioritization may result in discrete target areas for vaccination campaigns; thus, there are tradeoffs to choosing one metric over another. However, in some cases, certain areas may be prioritized by all three metrics. These areas should be treated with particular concern. Furthermore, the spatial scale at which each metric is calculated impacts the resulting prioritization and should also be considered when prioritizing areas for vaccination campaigns. These methods may be used to allocate effort for prophylactic campaigns or to prioritize response for outbreak response vaccination.
42 CFR 435.4 - Definitions and use of terms.
Code of Federal Regulations, 2010 CFR
2010-10-01
... disabled individual; Optional targeted low-income child means a child under age 19 who meets the financial and categorical standards described below. (1) Financial need. An optional targeted low-income child... optional targeted low-income child is not covered under a group health plan or health insurance coverage...
Kanya, Lucy; Obare, Francis; Warren, Charlotte; Abuya, Timothy; Askew, Ian; Bellows, Ben
2014-07-01
There has been increased interest in and experimentation with demand-side mechanisms such as the use of vouchers that place purchasing power in the hands of targeted consumers to improve the uptake of healthcare services in low-income settings. A key measure of the success of such interventions is the extent to which the programmes have succeeded in reaching the target populations. This article estimates the coverage of facility deliveries by a maternal health voucher programme in South-western Uganda and examines whether such coverage is correlated with district-level characteristics such as poverty density and the number of contracted facilities. Analysis entails estimating the voucher coverage of health facility deliveries among the general population and poor population (PP) using programme data for 2010, which was the most complete calendar year of implementation of the Uganda safe motherhood (SM) voucher programme. The results show that: (1) the programme paid for 38% of estimated deliveries among the PP in the targeted districts, (2) there was a significant negative correlation between the poverty density in a district and proportions of births to poor women that were covered by the programme and (3) improving coverage of health facility deliveries for poor women is dependent upon increasing the sales and redemption rates. The findings suggest that to the extent that the programme stimulated demand for SM services by new users, it has the potential of increasing facility-based births among poor women in the region. In addition, the significant negative correlation between the poverty density and the proportions of facility-based births to poor women that are covered by the voucher programme suggests that there is need to increase both voucher sales and the rate of redemption to improve coverage in districts with high levels of poverty. Published by Oxford University Press in association with The London School of Hygiene and Tropical Medicine © The Author 2013; all rights reserved.
Arbyn, Marc; Fabri, Valérie; Temmerman, Marleen; Simoens, Cindy
2014-01-01
To assess the coverage for cervical cancer screening as well as the use of cervical cytology, colposcopy and other diagnostic and therapeutic interventions on the uterine cervix in Belgium, using individual health insurance data. The Intermutualistic Agency compiled a database containing 14 million records from reimbursement claims for Pap smears, colposcopies, cervical biopsies and surgery, performed between 2002 and 2006. Cervical cancer screening coverage was defined as the proportion of women aged 25-64 that had a Pap smear within the last 3 years. Cervical cancer screening coverage was 61% at national level, for the target population of women between 25 and 64 years old, in the period 2004-2006. Differences between the 3 regions were small, but varied more substantially between provinces. Coverage was 70% for 25-34 year old women, 67% for those aged 35-39 years, and decreased to 44% in the age group of 60-64 years. The median screening interval was 13 months. The screening coverage varied substantially by social category: 40% and 64%, in women categorised as beneficiary or not-beneficiary of increased reimbursement from social insurance, respectively. In the 3-year period 2004-2006, 3.2 million screen tests were done in the target group consisting of 2.8 million women. However, only 1.7 million women got one or more smears and 1.1 million women had no smears, corresponding to an average of 1.88 smears per woman in three years of time. Colposcopy was excessively used (number of Pap smears over colposcopies = 3.2). The proportion of women with a history of conisation or hysterectomy, before the age of 65, was 7% and 19%, respectively. The screening coverage increased slightly from 59% in 2000 to 61% in 2006. The screening intensity remained at a high level, and the number of cytological examinations was theoretically sufficient to cover more than the whole target population.
Progress Toward Measles Elimination - African Region, 2013-2016.
Masresha, Balcha G; Dixon, Meredith G; Kriss, Jennifer L; Katsande, Reggis; Shibeshi, Messeret E; Luce, Richard; Fall, Amadou; Dosseh, Annick R G A; Byabamazima, Charles R; Dabbagh, Alya J; Goodson, James L; Mihigo, Richard
2017-05-05
In 2011, the 46 World Health Organization (WHO) African Region (AFR) member states established a goal of measles elimination* by 2020, by achieving 1) ≥95% coverage of their target populations with the first dose of measles-containing vaccine (MCV1) at national and district levels; 2) ≥95% coverage with measles-containing vaccine (MCV) per district during supplemental immunization activities (SIAs); and 3) confirmed measles incidence of <1 case per 1 million population in all countries (1). Two key surveillance performance indicator targets include 1) investigating ≥2 cases of nonmeasles febrile rash illness per 100,000 population annually, and 2) obtaining a blood specimen from ≥1 suspected measles case in ≥80% of districts annually (2). This report updates the previous report (3) and describes progress toward measles elimination in AFR during 2013-2016. Estimated regional MCV1 coverage † increased from 71% in 2013 to 74% in 2015. § Seven (15%) countries achieved ≥95% MCV1 coverage in 2015. ¶ The number of countries providing a routine second MCV dose (MCV2) increased from 11 (24%) in 2013 to 23 (49%) in 2015. Forty-one (79%) of 52 SIAs** during 2013-2016 reported ≥95% coverage. Both surveillance targets were met in 19 (40%) countries in 2016. Confirmed measles incidence in AFR decreased from 76.3 per 1 million population to 27.9 during 2013-2016. To eliminate measles by 2020, AFR countries and partners need to 1) achieve ≥95% 2-dose MCV coverage through improved immunization services, including second dose (MCV2) introduction; 2) improve SIA quality by preparing 12-15 months in advance, and using readiness, intra-SIA, and post-SIA assessment tools; 3) fully implement elimination-standard surveillance †† ; 4) conduct annual district-level risk assessments; and 5) establish national committees and a regional commission for the verification of measles elimination.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Koay, Eugene J.; Lege, David; Mohan, Radhe
Purpose: To analyze dosimetric variables and outcomes after adaptive replanning of radiation therapy during concurrent high-dose protons and chemotherapy for locally advanced non-small cell lung cancer (NSCLC). Methods and Materials: Nine of 44 patients with stage III NSCLC in a prospective phase II trial of concurrent paclitaxel/carboplatin with proton radiation [74 Gy(RBE) in 37 fractions] had modifications to their original treatment plans after re-evaluation revealed changes that would compromise coverage of the target volume or violate dose constraints; plans for the other 35 patients were not changed. We compared patients with adaptive plans with those with nonadaptive plans in termsmore » of dosimetry and outcomes. Results: At a median follow-up of 21.2 months (median overall survival, 29.6 months), no differences were found in local, regional, or distant failure or overall survival between groups. Adaptive planning was used more often for large tumors that shrank to a greater extent (median, 107.1 cm{sup 3} adaptive and 86.4 cm{sup 3} nonadaptive; median changes in volume, 25.3% adaptive and 1.2% nonadaptive; P<.01). The median number of fractions delivered using adaptive planning was 13 (range, 4-22). Adaptive planning generally improved sparing of the esophagus (median absolute decrease in V{sub 70}, 1.8%; range, 0%-22.9%) and spinal cord (median absolute change in maximum dose, 3.7 Gy; range, 0-13.8 Gy). Without adaptive replanning, target coverage would have been compromised in 2 cases (57% and 82% coverage without adaptation vs 100% for both with adaptation); neither patient experienced local failure. Radiation-related grade 3 toxicity rates were similar between groups. Conclusions: Adaptive planning can reduce normal tissue doses and prevent target misses, particularly for patients with large tumors that shrink substantially during therapy. Adaptive plans seem to have acceptable toxicity and achieve similar local, regional, and distant control and overall survival, even in patients with larger tumors, vs nonadaptive plans.« less
Koay, Eugene J; Lege, David; Mohan, Radhe; Komaki, Ritsuko; Cox, James D; Chang, Joe Y
2012-12-01
To analyze dosimetric variables and outcomes after adaptive replanning of radiation therapy during concurrent high-dose protons and chemotherapy for locally advanced non-small cell lung cancer (NSCLC). Nine of 44 patients with stage III NSCLC in a prospective phase II trial of concurrent paclitaxel/carboplatin with proton radiation [74 Gy(RBE) in 37 fractions] had modifications to their original treatment plans after re-evaluation revealed changes that would compromise coverage of the target volume or violate dose constraints; plans for the other 35 patients were not changed. We compared patients with adaptive plans with those with nonadaptive plans in terms of dosimetry and outcomes. At a median follow-up of 21.2 months (median overall survival, 29.6 months), no differences were found in local, regional, or distant failure or overall survival between groups. Adaptive planning was used more often for large tumors that shrank to a greater extent (median, 107.1 cm(3) adaptive and 86.4 cm(3) nonadaptive; median changes in volume, 25.3% adaptive and 1.2% nonadaptive; P<.01). The median number of fractions delivered using adaptive planning was 13 (range, 4-22). Adaptive planning generally improved sparing of the esophagus (median absolute decrease in V(70), 1.8%; range, 0%-22.9%) and spinal cord (median absolute change in maximum dose, 3.7 Gy; range, 0-13.8 Gy). Without adaptive replanning, target coverage would have been compromised in 2 cases (57% and 82% coverage without adaptation vs 100% for both with adaptation); neither patient experienced local failure. Radiation-related grade 3 toxicity rates were similar between groups. Adaptive planning can reduce normal tissue doses and prevent target misses, particularly for patients with large tumors that shrink substantially during therapy. Adaptive plans seem to have acceptable toxicity and achieve similar local, regional, and distant control and overall survival, even in patients with larger tumors, vs nonadaptive plans. Copyright © 2012 Elsevier Inc. All rights reserved.
Arroz, Jorge A H; Candrinho, Baltazar; Mendis, Chandana; Varela, Pablo; Pinto, João; Martins, Maria do Rosário O
2018-02-05
In 2015, Mozambique piloted a new model of long-lasting insecticidal nets (LLINs) delivery in a campaign. The new delivery model was used in two rural districts were, and two others were considered as control, maintaining the old delivery model. The aim of this study is to compare the coverage of ownership and use of LLINs in intervention and control districts in Mozambique. A before-after design with control group was carried out 6 months after LLINs distribution. Using systematic probabilistic sampling, 1547 households were surveyed by means of a questionnaire. To find associations between the district categories (intervention and control) and the main outcomes of the study (LLIN ownership, use, and universal coverage achievement), odds ratio (OR) and respective confidence intervals were calculated. Of the 760 households surveyed in the intervention districts, 98.8% had at least one LLIN; of the 787 households surveyed in the control districts, 89.6% had at least one LLIN [OR: 9.7, 95% (CI 4.84-19.46)]. Around 95 and 87% of households owning at least one LLIN reported having slept under the LLIN the previous night in the intervention and control districts, respectively [OR: 3.2; 95% (CI 2.12-4.69)]. Seventy-one percent of the households surveyed achieved universal coverage in the intervention districts against 59.6% in the control districts [OR: 1.6; 95% (CI 1.33-2.03)]. The universal coverage campaign piloted with the new delivery model has increased LLINs ownership, use, and progression for reaching universal coverage targets in the community.
Impact of field number and beam angle on functional image-guided lung cancer radiotherapy planning
NASA Astrophysics Data System (ADS)
Tahir, Bilal A.; Bragg, Chris M.; Wild, Jim M.; Swinscoe, James A.; Lawless, Sarah E.; Hart, Kerry A.; Hatton, Matthew Q.; Ireland, Rob H.
2017-09-01
To investigate the effect of beam angles and field number on functionally-guided intensity modulated radiotherapy (IMRT) normal lung avoidance treatment plans that incorporate hyperpolarised helium-3 magnetic resonance imaging (3He MRI) ventilation data. Eight non-small cell lung cancer patients had pre-treatment 3He MRI that was registered to inspiration breath-hold radiotherapy planning computed tomography. IMRT plans that minimised the volume of total lung receiving ⩾20 Gy (V20) were compared with plans that minimised 3He MRI defined functional lung receiving ⩾20 Gy (fV20). Coplanar IMRT plans using 5-field manually optimised beam angles and 9-field equidistant plans were also evaluated. For each pair of plans, the Wilcoxon signed ranks test was used to compare fV20 and the percentage of planning target volume (PTV) receiving 90% of the prescription dose (PTV90). Incorporation of 3He MRI led to median reductions in fV20 of 1.3% (range: 0.2-9.3% p = 0.04) and 0.2% (range: 0 to 4.1%; p = 0.012) for 5- and 9-field arrangements, respectively. There was no clinically significant difference in target coverage. Functionally-guided IMRT plans incorporating hyperpolarised 3He MRI information can reduce the dose received by ventilated lung without comprising PTV coverage. The effect was greater for optimised beam angles rather than uniformly spaced fields.
Coverage Gains After the Affordable Care Act Among the Uninsured in Minnesota.
Call, Kathleen Thiede; Lukanen, Elizabeth; Spencer, Donna; Alarcón, Giovann; Kemmick Pintor, Jessie; Baines Simon, Alisha; Gildemeister, Stefan
2015-11-01
We determined whether and how Minnesotans who were uninsured in 2013 gained health insurance coverage in 2014, 1 year after the Affordable Care Act (ACA) expanded Medicaid coverage and enrollment. Insurance status and enrollment experiences came from the Minnesota Health Insurance Transitions Study (MH-HITS), a follow-up telephone survey of children and adults in Minnesota who had no health insurance in the fall of 2013. ACA had a tempered success in Minnesota. Outreach and enrollment efforts were effective; one half of those previously uninsured gained coverage, although many reported difficulty signing up (nearly 62%). Of the previously uninsured who gained coverage, 44% obtained their coverage through MNsure, Minnesota's insurance marketplace. Most of those who remained uninsured heard of MNsure and went to the Web site. Many still struggled with the enrollment process or reported being deterred by the cost of coverage. Targeting outreach, simplifying the enrollment process, focusing on affordability, and continuing funding for in-person assistance will be important in the future.
Coverage Gains After the Affordable Care Act Among the Uninsured in Minnesota
Lukanen, Elizabeth; Spencer, Donna; Alarcón, Giovann; Kemmick Pintor, Jessie; Baines Simon, Alisha; Gildemeister, Stefan
2015-01-01
Objectives. We determined whether and how Minnesotans who were uninsured in 2013 gained health insurance coverage in 2014, 1 year after the Affordable Care Act (ACA) expanded Medicaid coverage and enrollment. Methods. Insurance status and enrollment experiences came from the Minnesota Health Insurance Transitions Study (MH-HITS), a follow-up telephone survey of children and adults in Minnesota who had no health insurance in the fall of 2013. Results. ACA had a tempered success in Minnesota. Outreach and enrollment efforts were effective; one half of those previously uninsured gained coverage, although many reported difficulty signing up (nearly 62%). Of the previously uninsured who gained coverage, 44% obtained their coverage through MNsure, Minnesota’s insurance marketplace. Most of those who remained uninsured heard of MNsure and went to the Web site. Many still struggled with the enrollment process or reported being deterred by the cost of coverage. Conclusions. Targeting outreach, simplifying the enrollment process, focusing on affordability, and continuing funding for in-person assistance will be important in the future. PMID:26447912
DNA barcoding in the media: does coverage of cool science reflect its social context?
Geary, Janis; Camicioli, Emma; Bubela, Tania
2016-09-01
Paul Hebert and colleagues first described DNA barcoding in 2003, which led to international efforts to promote and coordinate its use. Since its inception, DNA barcoding has generated considerable media coverage. We analysed whether this coverage reflected both the scientific and social mandates of international barcoding organizations. We searched newspaper databases to identify 900 English-language articles from 2003 to 2013. Coverage of the science of DNA barcoding was highly positive but lacked context for key topics. Coverage omissions pose challenges for public understanding of the science and applications of DNA barcoding; these included coverage of governance structures and issues related to the sharing of genetic resources across national borders. Our analysis provided insight into how barcoding communication efforts have translated into media coverage; more targeted communication efforts may focus media attention on previously omitted, but important topics. Our analysis is timely as the DNA barcoding community works to establish the International Society for the Barcode of Life.
Determinants of Vaccination Coverage and Consequences for Rabies Control in Bali, Indonesia.
Arief, Riana A; Hampson, Katie; Jatikusumah, Andri; Widyastuti, Maria D W; Sunandar; Basri, Chaerul; Putra, Anak A G; Willyanto, Iwan; Estoepangestie, Agnes T S; Mardiana, I W; Kesuma, I K G N; Sumantra, I P; Doherty, Paul F; Salman, M D; Gilbert, Jeff; Unger, Fred
2016-01-01
Maintaining high vaccination coverage is key to successful rabies control, but mass dog vaccination can be challenging and population turnover erodes coverage. Declines in rabies incidence following successive island-wide vaccination campaigns in Bali suggest that prospects for controlling and ultimately eliminating rabies are good. Rabies, however, has continued to circulate at low levels. In the push to eliminate rabies from Bali, high coverage needs to be maintained across all areas of the island. We carried out door-to-door (DTD) questionnaire surveys ( n = 10,352 dog-owning households) and photographic mark-recapture surveys (536 line transects, 2,597 observations of free-roaming dogs) in 2011-2012 to estimate dog population sizes and assess rabies vaccination coverage and dog demographic characteristics in Bali, Indonesia. The median number of dogs per subvillage unit ( banjar ) was 43 (range 0-307) for owned dogs estimated from the DTD survey and 17 (range 0-83) for unconfined dogs (including both owned and unowned) from transects. Vaccination coverage of owned dogs was significantly higher in adults (91.4%) compared to juveniles (<1 year, 43.9%), likely due to insufficient targeting of pups and from puppies born subsequent to vaccination campaigns. Juveniles had a 10-70 times greater risk of not being vaccinated in urban, suburban, and rural areas [combined odds ratios (ORs): 9.9-71.1, 95% CI: 8.6-96.0]. Free-roaming owned dogs were also 2-3 times more likely to be not vaccinated compared to those confined (combined Ors: 1.9-3.6, 95% CI: 1.4-5.4), with more dogs being confined in urban (71.2%) than in suburban (16.1%) and rural areas (8.0%). Vaccination coverage estimates from transects were also much lower (30.9%) than household surveys (83.6%), possibly due to loss of collars used to identify the vaccination status of free-roaming dogs, but these unconfined dogs may also include dogs that were unowned or more difficult to vaccinate. Overall, coverage levels were high in the owned dog population, but for future campaigns in Bali to have the highest chance of eliminating rabies, concerted effort should be made to vaccinate free-roaming dogs particularly in suburban and rural areas, with advertising to ensure that owners vaccinate pups. Long-lasting, cheap, and quick methods are needed to mark vaccinated animals and reassure communities of the reach of vaccination campaigns.
Determinants of Vaccination Coverage and Consequences for Rabies Control in Bali, Indonesia
Arief, Riana A.; Hampson, Katie; Jatikusumah, Andri; Widyastuti, Maria D. W.; Sunandar; Basri, Chaerul; Putra, Anak A. G.; Willyanto, Iwan; Estoepangestie, Agnes T. S.; Mardiana, I. W.; Kesuma, I. K. G. N.; Sumantra, I. P.; Doherty, Paul F.; Salman, M. D.; Gilbert, Jeff; Unger, Fred
2017-01-01
Maintaining high vaccination coverage is key to successful rabies control, but mass dog vaccination can be challenging and population turnover erodes coverage. Declines in rabies incidence following successive island-wide vaccination campaigns in Bali suggest that prospects for controlling and ultimately eliminating rabies are good. Rabies, however, has continued to circulate at low levels. In the push to eliminate rabies from Bali, high coverage needs to be maintained across all areas of the island. We carried out door-to-door (DTD) questionnaire surveys (n = 10,352 dog-owning households) and photographic mark–recapture surveys (536 line transects, 2,597 observations of free-roaming dogs) in 2011–2012 to estimate dog population sizes and assess rabies vaccination coverage and dog demographic characteristics in Bali, Indonesia. The median number of dogs per subvillage unit (banjar) was 43 (range 0–307) for owned dogs estimated from the DTD survey and 17 (range 0–83) for unconfined dogs (including both owned and unowned) from transects. Vaccination coverage of owned dogs was significantly higher in adults (91.4%) compared to juveniles (<1 year, 43.9%), likely due to insufficient targeting of pups and from puppies born subsequent to vaccination campaigns. Juveniles had a 10–70 times greater risk of not being vaccinated in urban, suburban, and rural areas [combined odds ratios (ORs): 9.9–71.1, 95% CI: 8.6–96.0]. Free-roaming owned dogs were also 2–3 times more likely to be not vaccinated compared to those confined (combined Ors: 1.9–3.6, 95% CI: 1.4–5.4), with more dogs being confined in urban (71.2%) than in suburban (16.1%) and rural areas (8.0%). Vaccination coverage estimates from transects were also much lower (30.9%) than household surveys (83.6%), possibly due to loss of collars used to identify the vaccination status of free-roaming dogs, but these unconfined dogs may also include dogs that were unowned or more difficult to vaccinate. Overall, coverage levels were high in the owned dog population, but for future campaigns in Bali to have the highest chance of eliminating rabies, concerted effort should be made to vaccinate free-roaming dogs particularly in suburban and rural areas, with advertising to ensure that owners vaccinate pups. Long-lasting, cheap, and quick methods are needed to mark vaccinated animals and reassure communities of the reach of vaccination campaigns. PMID:28119919
Ships and Maritime Targets Observation Campaigns Using Available C- and X-Band SAR Satellite
NASA Astrophysics Data System (ADS)
Velotto, Domenico; Bentes, Carlos; Lehner, Susanne
2015-04-01
Obviously, radar resolution and swath width are two very important factors when it comes to synthetic aperture radar (SAR) maritime targets detections. The dilemma of using single polarization SAR imagery with higher resolution and coverage or quad- (or dual- polarimetric) imagery with its richness of information, is still unsolved when it comes to this application.In the framework of ESA project MARISS and EU project DOLPHIN, in situ campaigns aimed at solving this dilemma have been carried out. Single and multi- polarimetric SAR data acquired by TerraSAR-X, RADARSAT-2 and COSMO-SkyMed have been acquired with close time gaps and partial coverage overlap. In this way several moving and non-moving maritime targets have been imaged with different polarization, geometry and working frequency. Available ground truth reports provided by Automatic Identification System (AIS) data, nautical chart and wind farm location are used to validate the different types of maritime targets.
Targeted Help for Spoken Dialogue Systems: Intelligent Feedback Improves Naive Users' Performance
NASA Technical Reports Server (NTRS)
Hockey, Beth Ann; Lemon, Oliver; Campana, Ellen; Hiatt, Laura; Aist, Gregory; Hieronymous, Jim; Gruenstein, Alexander; Dowding, John
2003-01-01
We present experimental evidence that providing naive users of a spoken dialogue system with immediate help messages related to their out-of-coverage utterances improves their success in using the system. A grammar-based recognizer and a Statistical Language Model (SLM) recognizer are run simultaneously. If the grammar-based recognizer suceeds, the less accurate SLM recognizer hypothesis is not used. When the grammar-based recognizer fails and the SLM recognizer produces a recognition hypothesis, this result is used by the Targeted Help agent to give the user feed-back on what was recognized, a diagnosis of what was problematic about the utterance, and a related in-coverage example. The in-coverage example is intended to encourage alignment between user inputs and the language model of the system. We report on controlled experiments on a spoken dialogue system for command and control of a simulated robotic helicopter.
Ferrari, M J; Grenfell, B T; Strebel, P M
2013-08-05
The global reduction of the burden of morbidity and mortality owing to measles has been a major triumph of public health. However, the continued persistence of measles infection probably not only reflects local variation in progress towards vaccination target goals, but may also reflect local variation in dynamic processes of transmission, susceptible replenishment through births and stochastic local extinction. Dynamic models predict that vaccination should increase the mean age of infection and increase inter-annual variability in incidence. Through a comparative approach, we assess national-level patterns in the mean age of infection and measles persistence. We find that while the classic predictions do hold in general, the impact of vaccination on the age distribution of cases and stochastic fadeout are mediated by local birth rate. Thus, broad-scale vaccine coverage goals are unlikely to have the same impact on the interruption of measles transmission in all demographic settings. Indeed, these results suggest that the achievement of further measles reduction or elimination goals is likely to require programmatic and vaccine coverage goals that are tailored to local demographic conditions.
Bastawrous, Andrew; Mathenge, Wanjiku; Foster, Allen; Kuper, Hannah
2013-10-01
A cross-sectional study was undertaken in Nakuru, Kenya to assess the prevalence of refractive error and the spectacle coverage in a population aged ≥50 years. Of the 5,010 subjects who were eligible, 4,414 underwent examination (response rate 88.1 %). LogMAR visual acuity was assessed in all participants and refractive error was measured in both eyes using a Topcon auto refractor RM8800. Detailed interviews were undertaken and ownership of spectacles was assessed. Refractive error was responsible for 51.7 % of overall visual impairment (VI), 85.3 % (n = 191) of subjects with mild VI, 42.7 % (n = 152) of subjects with moderate VI, 16.7 % (n = 3) of subjects with severe VI and no cases of blindness. Myopia was more common than hyperopia affecting 59.5 % of those with refractive error compared to 27.4 % for hyperopia. High myopia (<-5.0 DS) was also more common than extreme hyperopia (>+5.0 DS). Of those who needed distance spectacles (spectacle coverage), 25.5 % owned spectacles. In conclusion, the oldest, most poor and least educated are most likely to have no spectacles and they should be specifically targeted when refractive services are put in place.
Basu, Sanjay; Bendavid, Eran; Sood, Neeraj
2015-11-01
Whether to cover cardiovascular disease costs is an increasingly pressing question for low- and middle-income countries. We sought to identify the impact of expanding national insurance to cover primary prevention, secondary prevention, and tertiary treatment for cardiovascular disease in India. We incorporated data from coverage experiments into a validated microsimulation model of myocardial infarction and stroke in India to evaluate the cost-effectiveness of alternate coverage strategies. Coverage of primary prevention alone saved 3.6 million disability-adjusted life-years (DALY) per annum at an incremental cost-effectiveness ratio of $469 per DALY averted when compared with the status quo of no coverage. Coverage of primary and secondary preventions was dominated by a strategy of covering primary prevention and tertiary treatment, which prevented 6.6 million DALYs at an incremental cost-effectiveness ratio of $2241 per DALY averted, when compared with that of primary prevention alone. The combination of all 3 categories yielded the greatest impact at an incremental cost per DALY averted of $5588 when compared with coverage of primary prevention plus tertiary treatment. When compared with the status quo of no coverage, coverage of all 3 categories of prevention/treatment yielded an incremental cost-effectiveness ratio of $1331 per DALY averted. In sensitivity analyses, coverage of primary preventive treatments remained cost-effective even if adherence and access to therapy were low, but tertiary coverage would require avoiding unnecessary procedures to remain cost-effective. Coverage of all 3 major types of cardiovascular treatment would be expected to have high impact and reasonable cost-effectiveness in India across a broad spectrum of access and adherence levels. © 2015 American Heart Association, Inc.
Lin, Jing; Pramono, Zacharias Aloysius Dwi; Maurer-Stroh, Sebastian
2016-01-01
The multiple circulating human influenza A virus subtypes coupled with the perpetual genomic mutations and segment reassortment events challenge the development of effective therapeutics. The capacity to drug most RNAs motivates the investigation on viral RNA targets. 123,060 segment sequences from 35,938 strains of the most prevalent subtypes also infecting humans–H1N1, 2009 pandemic H1N1, H3N2, H5N1 and H7N9, were used to identify 1,183 conserved RNA target sequences (≥15-mer) in the internal segments. 100% theoretical coverage in simultaneous heterosubtypic targeting is achieved by pairing specific sequences from the same segment (“Duals”) or from two segments (“Doubles”); 1,662 Duals and 28,463 Doubles identified. By combining specific Duals and/or Doubles to form a target graph wherein an edge connecting two vertices (target sequences) represents a Dual or Double, it is possible to hedge against antiviral resistance besides maintaining 100% heterosubtypic coverage. To evaluate the hedging potential, we define the hedge-factor as the minimum number of resistant target sequences that will render the graph to become resistant i.e. eliminate all the edges therein; a target sequence or a graph is considered resistant when it cannot achieve 100% heterosubtypic coverage. In an n-vertices graph (n ≥ 3), the hedge-factor is maximal (= n– 1) when it is a complete graph i.e. every distinct pair in a graph is either a Dual or Double. Computational analyses uncover an extensive number of complete graphs of different sizes. Monte Carlo simulations show that the mutation counts and time elapsed for a target graph to become resistant increase with the hedge-factor. Incidentally, target sequences which were reported to reduce virus titre in experiments are included in our target graphs. The identity of target sequence pairs for heterosubtypic targeting and their combinations for hedging antiviral resistance are useful toolkits to construct target graphs for different therapeutic objectives. PMID:26771381
Chapman, Audrey R
2016-12-15
The UN's Sustainable Development Goals (SDGs), adopted in September 2015, include a comprehensive health goal, "to ensure healthy lives and promote well-being at all ages." The health goal (SDG 3) has nine substantive targets and four additional targets which are identified as a means of implementation. One of these commitments, to achieve universal health coverage (UHC), has been acknowledged as central to the achievement of all of the other health targets. As defined in the SDGs, UHC includes financial risk protection, access to quality essential health-care services, and access to safe, effective, quality and affordable essential medicines and vaccines for all. This article evaluates the extent to which the UHC target in the SDGs conforms with the requirements of the right to health enumerated in the International Covenant on Economic, Social and Cultural Rights, the Convention on the Rights of the Child, and other international human rights instruments and interpreted by international human rights bodies. It does so as a means to identify strengths and weaknesses in the framing of the UHC target that are likely to affect its implementation. While UHC as defined in the SDGs overlaps with human rights standards, there are important human rights omissions that will likely weaken the implementation and reduce the potential benefits of the UHC target. The most important of these is the failure to confer priority to providing access to health services to poor and disadvantaged communities in the process of expanding health coverage and in determining which health services to provide. Unless the furthest behind are given priority and strategies adopted to secure their participation in the development of national health plans, the SDGs, like the MDGs, are likely to leave the most disadvantaged and vulnerable communities behind.
Alberti, K P; Guthmann, J P; Fermon, F; Nargaye, K D; Grais, R F
2008-03-01
Inadequate evaluation of vaccine coverage after mass vaccination campaigns, such as used in national measles control programmes, can lead to inappropriate public health responses. Overestimation of vaccination coverage may leave populations at risk, whilst underestimation can lead to unnecessary catch-up campaigns. The problem is more complex in large urban areas where vaccination coverage may be heterogeneous and the programme may have to be fine-tuned at the level of geographic subunits. Lack of accurate population figures in many contexts further complicates accurate vaccination coverage estimates. During the evaluation of a mass vaccination campaign carried out in N'Djamena, the capital of Chad, Lot Quality Assurance Sampling was used to estimate vaccination coverage. Using this method, vaccination coverage could be evaluated within smaller geographic areas of the city as well as for the entire city. Despite the lack of accurate population data by neighbourhood, the results of the survey showed heterogeneity of vaccination coverage within the city. These differences would not have been identified using a more traditional method. The results can be used to target areas of low vaccination coverage during follow-up vaccination activities.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Harris, Victoria A.; Staffurth, John; Naismith, Olivia
Purpose: The purpose of this study was to establish reproducible guidelines for delineating the clinical target volume (CTV) of the pelvic lymph nodes (LN) by combining the freehand Royal Marsden Hospital (RMH) and Radiation Therapy Oncology Group (RTOG) vascular expansion techniques. Methods and Materials: Seven patients with prostate cancer underwent standard planning computed tomography scanning. Four different CTVs (RMH, RTOG, modified RTOG, and Prostate and pelvIs Versus prOsTate Alone treatment for Locally advanced prostate cancer [PIVOTAL] trial) were created for each patient, and 6 different bowel expansion margins (BEM) were created to assess bowel avoidance by the CTV. The resulting CTVsmore » were compared visually and by using Jaccard conformity indices. The volume of overlap between bowel and planning target volume (PTV) was measured to aid selection of an appropriate BEM to enable maximal LN yet minimal normal tissue coverage. Results: In total, 84 nodal contours were evaluated. LN coverage was similar in all groups, with all of the vascular-expansion techniques (RTOG, modified RTOG, and PIVOTAL), resulting in larger CTVs than that of the RMH technique (mean volumes: 287.3 cm{sup 3}, 326.7 cm{sup 3}, 310.3 cm{sup 3}, and 256.7 cm{sup 3}, respectively). Mean volumes of bowel within the modified RTOG PTV were 19.5 cm{sup 3} (with 0 mm BEM), 17.4 cm{sup 3} (1-mm BEM), 10.8 cm{sup 3} (2-mm BEM), 6.9 cm{sup 3} (3-mm BEM), 5.0 cm{sup 3} (4-mm BEM), and 1.4 cm{sup 3} (5-mm BEM) in comparison with an overlap of 9.2 cm{sup 3} seen using the RMH technique. Evaluation of conformity between LN-CTVs from each technique revealed similar volumes and coverage. Conclusions: Vascular expansion techniques result in larger LN-CTVs than the freehand RMH technique. Because the RMH technique is supported by phase 1 and 2 trial safety data, we proposed modifications to the RTOG technique, including the addition of a 3-mm BEM, which resulted in LN-CTV coverage similar to that of the RMH technique, with reduction in bowel and planning target volume overlap. On the basis of these findings, recommended guidelines including a detailed pelvic LN contouring atlas have been produced and implemented in the PIVOTAL trial.« less
Increasing Cervical Cancer Screening Coverage: A Randomised, Community-Based Clinical Trial
Acera, Amelia; Manresa, Josep Maria; Rodriguez, Diego; Rodriguez, Ana; Bonet, Josep Maria; Trapero-Bertran, Marta; Hidalgo, Pablo; Sànchez, Norman
2017-01-01
Background Opportunistic cervical cancer screening can lead to suboptimal screening coverage. Coverage could be increased after a personalised invitation to the target population. We present a community randomized intervention study with three strategies aiming to increase screening coverage. Methods The CRICERVA study is a community-based clinical trial to improve coverage of population-based screening in the Cerdanyola SAP area in Barcelona.A total of 32,858 women residing in the study area, aged 30 to 70 years were evaluated. A total of 15,965 women were identified as having no registration of a cervical cytology in the last 3.5 years within the Public Health data base system. Eligible women were assigned to one of four community randomized intervention groups (IGs): (1) (IG1 N = 4197) personalised invitation letter, (2) (IG2 N = 3601) personalised invitation letter + informative leaflet, (3) (IG3 N = 6088) personalised invitation letter + informative leaflet + personalised phone call and (4) (Control N = 2079) based on spontaneous demand of cervical cancer screening as officially recommended. To evaluate screening coverage, we used heterogeneity tests to compare impact of the interventions and mixed logistic regression models to assess the age effect. We refer a “rescue” visit as the screening visit resulting from the study invitation. Results Among the 13,886 women in the IGs, 2,862 were evaluated as having an adequate screening history after the initial contact; 4,263 were lost to follow-up and 5,341 were identified as having insufficient screening and thus being eligible for a rescue visit. All intervention strategies significantly increased participation to screening compared to the control group. Coverage after the intervention reached 84.1% while the control group reached 64.8%. The final impact of our study was an increase of 20% in the three IGs and of 9% in the control group (p<0.001). Within the intervention arms, age was an important determinant of rescue visits showing a statistical interaction with the coverage attained in the IGs. Within the intervention groups, final screening coverage was significantly higher in IG3 (84.4%) (p<0.001). However, the differences were more substantial in the age groups 50–59 and those 60+. The highest impact of the IG3 intervention was observed among women 60+ y.o with 32.0% of them being rescued for screening. The lowest impact of the interventions was in younger women. Conclusions The study confirms that using individual contact methods and assigning a fixed screening date notably increases participation in screening. The response to the invitation is strongly dependent on age. Trial Registration ClinicalTrials.gov NCT01373723 PMID:28118410
Palmer, Antony L; Nash, David; Kearton, John R; Jafari, Shakardokht M; Muscat, Sarah
2017-12-01
External dosimetry audit is valuable for the assurance of radiotherapy quality. However, motion management has not been rigorously audited, despite its complexity and importance for accuracy. We describe the first end-to-end dosimetry audit for non-SABR (stereotactic ablative body radiotherapy) lung treatments, measuring dose accumulation in a moving target, and assessing adequacy of target dose coverage. A respiratory motion lung-phantom with custom-designed insert was used. Dose was measured with radiochromic film, employing triple-channel dosimetry and uncertainty reduction. The host's 4DCT scan, outlining and planning techniques were used. Measurements with the phantom static and then moving at treatment delivery separated inherent treatment uncertainties from motion effects. Calculated and measured dose distributions were compared by isodose overlay, gamma analysis, and we introduce the concept of 'dose plane histograms' for clinically relevant interpretation of film dosimetry. 12 radiotherapy centres and 19 plans were audited: conformal, IMRT (intensity modulated radiotherapy) and VMAT (volumetric modulated radiotherapy). Excellent agreement between planned and static-phantom results were seen (mean gamma pass 98.7% at 3% 2 mm). Dose blurring was evident in the moving-phantom measurements (mean gamma pass 88.2% at 3% 2 mm). Planning techniques for motion management were adequate to deliver the intended moving-target dose coverage. A novel, clinically-relevant, end-to-end dosimetry audit of motion management strategies in radiotherapy is reported. Copyright © 2017 Elsevier B.V. All rights reserved.
How do top cable news websites portray cognition as an aging issue?
Vandenberg, Anna E; Price, Anna E; Friedman, Daniela B; Marchman, Graham; Anderson, Lynda A
2012-06-01
We examined messages that the websites of the top cable news companies (MSNBC, FOX, and CNN) conveyed about cognition between January 2007 and March 2010. Drawing on agenda-setting theory, this work assessed the frequency, prominence, and attributes of cognitive topics in messages targeting an aging audience. We used quantitative content analysis to examine the frequency and prominence of cognitive topics and cognitive goals, as well as how the cognitive discussions were framed. Chi-square analyses were conducted to compare cognitive health information discussed in news items that did and did not target an "aging audience." Qualitative analysis of the aging audience subgroup was used to further examine age-associated cognitive messages. Within the 229 cognitive items identified, we found significantly more coverage of cognitive functioning and unspecified dementia and significantly less coverage of cognitive disease not dementia, specified dementia, and accidents or injury for the aging audience. Our qualitative analysis of news items aimed at an aging audience documented a focus on maintaining functioning and avoiding decline through various individual lifestyle behaviors. However, contextual information about level of cognition to be maintained, particular cognitive functions targeted, specific norms about cognitive aging, and how cognitive function is determined was lacking. Our research points to a communication gap in the delivery of academic research findings to a lay audience through online journalism. We suggest more clarity by researchers in defining cognitive concepts and measurement of cognitive function for journalistic translation and public consumption.
Byrne, L; Ward, C; White, J M; Amirthalingam, G; Edelstein, M
2018-01-01
This study assessed variation in coverage of maternal pertussis vaccination, introduced in England in October 2012 in response to a national outbreak, and a new infant rotavirus vaccination programme, implemented in July 2013. Vaccine eligible patients were included from national vaccine coverage datasets and covered April 2014 to March 2015 for pertussis and January 2014 to June 2016 for rotavirus. Vaccine coverage (%) was calculated overall and by NHS England Local Team (LT), ethnicity and Index of Multiple Deprivation (IMD) quintile, and compared using binomial regression. Compared with white-British infants, the largest differences in rotavirus coverage were in 'other', white-Irish and black-Caribbean infants (-13·9%, -12·1% and -10·7%, respectively), after adjusting for IMD and LT. The largest differences in maternal pertussis coverage were in black-other and black-Caribbean women (-16·3% and -15·4%, respectively). Coverage was lowest in London LT for both programmes. Coverage decreased with increasing deprivation and was 14·0% lower in the most deprived quintile compared with the least deprived for the pertussis programme and 4·4% lower for rotavirus. Patients' ethnicity and deprivation were therefore predictors of coverage which contributed to, but did not wholly account for, geographical variation in coverage in England.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Patel, Pretesh R., E-mail: patel073@mc.duke.edu; Yoo, Sua; Broadwater, Gloria
Purpose: To assess the impact of increasing experience with intensity-modulated radiation therapy (IMRT) after extrapleural pneumonectomy (EPP) for malignant pleural mesothelioma (MPM). Methods and Materials: The records of all patients who received IMRT following EPP at Duke University Medical Center between 2005 and 2010 were reviewed. Target volumes included the preoperative extent of the pleural space, chest wall incisions, involved nodal stations, and a boost to close/positive surgical margins if applicable. Patients were typically treated with 9-11 beams with gantry angles, collimator rotations, and beam apertures manually fixed to avoid the contalateral lung and to optimize target coverage. Toxicity wasmore » graded retrospectively using National Cancer Institute common toxicity criteria version 4.0. Target coverage and contralateral lung irradiation were evaluated over time by using linear regression. Local control, disease-free survival, and overall survival rates were estimated using the Kaplan-Meier method. Results: Thirty patients received IMRT following EPP; 21 patients also received systemic chemotherapy. Median follow-up was 15 months. The median dose prescribed to the entire ipsilateral hemithorax was 45 Gy (range, 40-50.4 Gy) with a boost of 8-25 Gy in 9 patients. Median survival was 23.2 months. Two-year local control, disease-free survival, and overall survival rates were 47%, 34%, and 50%, respectively. Increasing experience planning MPM cases was associated with improved coverage of planning target volumes (P=.04). Similarly, mean lung dose (P<.01) and lung V5 (volume receiving 5 Gy or more; P<.01) values decreased with increasing experience. Lung toxicity developed after IMRT in 4 (13%) patients at a median of 2.2 months after RT (three grade 3-4 and one grade 5). Lung toxicity developed in 4 of the initial 15 patients vs none of the last 15 patients treated. Conclusions: With increasing experience, target volume coverage improved and dose to the contralateral lung decreased. Rates of pulmonary toxicity were relatively low. However, both local and distant control rates remained suboptimal.« less
Parker, Lucy A; Rumunu, John; Jamet, Christine; Kenyi, Yona; Lino, Richard Laku; Wamala, Joseph F; Mpairwe, Allan M; Muller, Vincent; Llosa, Augusto E; Uzzeni, Florent; Luquero, Francisco J; Ciglenecki, Iza; Azman, Andrew S
2017-06-01
In June 2015, a cholera outbreak was declared in Juba, South Sudan. In addition to standard outbreak control measures, oral cholera vaccine (OCV) was proposed. As sufficient doses to cover the at-risk population were unavailable, a campaign using half the standard dosing regimen (one-dose) targeted high-risk neighborhoods and groups including neighbors of suspected cases. Here we report the operational details of this first public health use of a single-dose regimen of OCV and illustrate the feasibility of conducting highly targeted vaccination campaigns in an urban area. Neighborhoods of the city were prioritized for vaccination based on cumulative attack rates, active transmission and local knowledge of known cholera risk factors. OCV was offered to all persons older than 12 months at 20 fixed sites and to select groups, including neighbors of cholera cases after the main campaign ('case-triggered' interventions), through mobile teams. Vaccination coverage was estimated by multi-stage surveys using spatial sampling techniques. 162,377 individuals received a single-dose of OCV in the targeted neighborhoods. In these neighborhoods vaccine coverage was 68.8% (95% Confidence Interval (CI), 64.0-73.7) and was highest among children ages 5-14 years (90.0%, 95% CI 85.7-94.3), with adult men being less likely to be vaccinated than adult women (Relative Risk 0.81, 95% CI: 0.68-0.96). In the case-triggered interventions, each lasting 1-2 days, coverage varied (range: 30-87%) with an average of 51.0% (95% CI 41.7-60.3). Vaccine supply constraints and the complex realities where cholera outbreaks occur may warrant the use of flexible alternative vaccination strategies, including highly-targeted vaccination campaigns and single-dose regimens. We showed that such campaigns are feasible. Additional work is needed to understand how and when to use different strategies to best protect populations against epidemic cholera.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Moignier, Alexandra, E-mail: alexandra-moignier@uiowa.edu; Gelover, Edgar; Wang, Dongxu
Purpose: To quantify the dosimetric benefit of using a dynamic collimation system (DCS) for penumbra reduction during the treatment of brain tumors by pencil beam scanning proton therapy (PBS PT). Methods and Materials: Collimated and uncollimated brain treatment plans were created for 5 patients previously treated with PBS PT and retrospectively enrolled in an institutional review board–approved study. The in-house treatment planning system, RDX, was used to generate the plans because it is capable of modeling both collimated and uncollimated beamlets. The clinically delivered plans were reproduced with uncollimated plans in terms of target coverage and organ at risk (OAR) sparingmore » to ensure a clinically relevant starting point, and collimated plans were generated to improve the OAR sparing while maintaining target coverage. Physical and biological comparison metrics, such as dose distribution conformity, mean and maximum doses, normal tissue complication probability, and risk of secondary brain cancer, were used to evaluate the plans. Results: The DCS systematically improved the dose distribution conformity while preserving the target coverage. The average reduction of the mean dose to the 10-mm ring surrounding the target and the healthy brain were 13.7% (95% confidence interval [CI] 11.6%-15.7%; P<.0001) and 25.1% (95% CI 16.8%-33.4%; P<.001), respectively. This yielded an average reduction of 24.8% (95% CI 0.8%-48.8%; P<.05) for the brain necrosis normal tissue complication probability using the Flickinger model, and 25.1% (95% CI 16.8%-33.4%; P<.001) for the risk of secondary brain cancer. A general improvement of the OAR sparing was also observed. Conclusion: The lateral penumbra reduction afforded by the DCS increases the normal tissue sparing capabilities of PBS PT for brain cancer treatment while preserving target coverage.« less
Analysis of esophageal-sparing treatment plans for patients with high-grade esophagitis.
Niedzielski, Joshua; Bluett, Jaques B; Williamson, Ryan T; Liao, Zhongxing; Gomez, Daniel R; Court, Laurence E
2013-07-08
We retrospectively generated IMRT plans for 14 NSCLC patients who had experienced grade 2 or 3 esophagitis (CTCAE version 3.0). We generated 11-beam and reduced esophagus dose plan types to compare changes in the volume and length of esophagus receiving doses of 50, 55, 60, 65, and 70 Gy. Changes in planning target volume (PTV) dose coverage were also compared. If necessary, plans were renormalized to restore 95% PTV coverage. The critical organ doses examined were mean lung dose, mean heart dose, and volume of spinal cord receiving 50 Gy. The effect of interfractional motion was determined by applying a three-dimensional rigid shift to the dose grid. For the esophagus plan, the mean reduction in esophagus V50, V55, V60, V65, and V70 Gy was 2.8, 4.1, 5.9, 7.3, and 9.5 cm(3), respectively, compared with the clinical plan. The mean reductions in LE50, LE55, LE60, LE65, and LE70 Gy were 2.0, 3.0, 3.8, 4.0, and 4.6 cm, respectively. The mean heart and lung dose decreased 3.0 Gy and 2.4 Gy, respectively. The mean decreases in 90% and 95% PTV coverage were 1.7 Gy and 2.8 Gy, respectively. The normalized plans' mean reduction of esophagus V50, V55, V60, V65, and V70 Gy were 1.6, 2.0, 2.9, 3.9, and 5.5 cm(3), respectively, compared with the clinical plans. The normalized plans' mean reductions in LE50, LE55, LE60, LE65, and LE70 Gy were 4.9, 5.2, 5.4, 4.9, and 4.8 cm, respectively. The mean reduction in maximum esophagus dose with simulated interfractional motion was 3.0 Gy and 1.4 Gy for the clinical plan type and the esophagus plan type, respectively. In many cases, the esophagus dose can be greatly reduced while maintaining critical structure dose constraints. PTV coverage can be restored by increasing beam output, while still obtaining a dose reduction to the esophagus and maintaining dose constraints.
Analysis of esophageal‐sparing treatment plans for patients with high‐grade esophagitis
Bluett, Jaques B.; Williamson, Ryan T.; Liao, Zhongxing; Gomez, Daniel R.; Court, Laurence E.
2013-01-01
We retrospectively generated IMRT plans for 14 NSCLC patients who had experienced grade 2 or 3 esophagitis (CTCAE version 3.0). We generated 11‐beam and reduced esophagus dose plan types to compare changes in the volume and length of esophagus receiving doses of 50, 55, 60, 65, and 70 Gy. Changes in planning target volume (PTV) dose coverage were also compared. If necessary, plans were renormalized to restore 95% PTV coverage. The critical organ doses examined were mean lung dose, mean heart dose, and volume of spinal cord receiving 50 Gy. The effect of interfractional motion was determined by applying a three‐dimensional rigid shift to the dose grid. For the esophagus plan, the mean reduction in esophagus V50, V55, V60, V65, and V70 Gy was 2.8, 4.1, 5.9, 7.3, and 9.5 cm3, respectively, compared with the clinical plan. The mean reductions in LE50, LE55, LE60, LE65, and LE70 Gy were 2.0, 3.0, 3.8, 4.0, and 4.6 cm, respectively. The mean heart and lung dose decreased 3.0 Gy and 2.4 Gy, respectively. The mean decreases in 90% and 95% PTV coverage were 1.7 Gy and 2.8 Gy, respectively. The normalized plans’ mean reduction of esophagus V50, V55, V60, V65, and V70 Gy were 1.6, 2.0, 2.9, 3.9, and 5.5 cm3, respectively, compared with the clinical plans. The normalized plans’ mean reductions in LE50, LE55, LE60, LE65, and LE70 Gy were 4.9, 5.2, 5.4, 4.9, and 4.8 cm, respectively. The mean reduction in maximum esophagus dose with simulated interfractional motion was 3.0 Gy and 1.4 Gy for the clinical plan type and the esophagus plan type, respectively. In many cases, the esophagus dose can be greatly reduced while maintaining critical structure dose constraints. PTV coverage can be restored by increasing beam output, while still obtaining a dose reduction to the esophagus and maintaining dose constraints. PACS number: 87.53 Tf PMID:23835390
Accurate and exact CNV identification from targeted high-throughput sequence data.
Nord, Alex S; Lee, Ming; King, Mary-Claire; Walsh, Tom
2011-04-12
Massively parallel sequencing of barcoded DNA samples significantly increases screening efficiency for clinically important genes. Short read aligners are well suited to single nucleotide and indel detection. However, methods for CNV detection from targeted enrichment are lacking. We present a method combining coverage with map information for the identification of deletions and duplications in targeted sequence data. Sequencing data is first scanned for gains and losses using a comparison of normalized coverage data between samples. CNV calls are confirmed by testing for a signature of sequences that span the CNV breakpoint. With our method, CNVs can be identified regardless of whether breakpoints are within regions targeted for sequencing. For CNVs where at least one breakpoint is within targeted sequence, exact CNV breakpoints can be identified. In a test data set of 96 subjects sequenced across ~1 Mb genomic sequence using multiplexing technology, our method detected mutations as small as 31 bp, predicted quantitative copy count, and had a low false-positive rate. Application of this method allows for identification of gains and losses in targeted sequence data, providing comprehensive mutation screening when combined with a short read aligner.
Inequities and their determinants in coverage of maternal health services in Burkina Faso.
Mwase, Takondwa; Brenner, Stephan; Mazalale, Jacob; Lohmann, Julia; Hamadou, Saidou; Somda, Serge M A; Ridde, Valery; De Allegri, Manuela
2018-05-11
Poor and marginalized segments of society often display the worst health status due to limited access to health enhancing interventions. It follows that in order to enhance the health status of entire populations, inequities in access to health care services need to be addressed as an inherent element of any effort targeting Universal Health Coverage. In line with this observation and the need to generate evidence on the equity status quo in sub-Saharan Africa, we assessed the magnitude of the inequities and their determinants in coverage of maternal health services in Burkina Faso. We assessed coverage for three basic maternal care services (at least four antenatal care visits, facility-based delivery, and at least one postnatal care visit) using data from a cross-sectional household survey including a total of 6655 mostly rural, poor women who had completed a pregnancy in the 24 months prior to the survey date. We assessed equity along the dimensions of household wealth, distance to the health facility, and literacy using both simple comparative measures and concentration indices. We also ran hierarchical random effects regression to confirm the presence or absence of inequities due to household wealth, distance, and literacy, while controlling for potential confounders. Coverage of facility based delivery was high (89%), but suboptimal for at least four antenatal care visits (44%) and one postnatal care visit (53%). We detected inequities along the dimensions of household wealth, literacy and distance. Service coverage was higher among the least poor, those who were literate, and those living closer to a health facility. We detected a significant positive association between household wealth and all outcome variables, and a positive association between literacy and facility-based delivery. We detected a negative association between living farther away from the catchment facility and all outcome variables. Existing inequities in maternal health services in Burkina Faso are likely going to jeopardize the achievement of Universal Health Coverage. It is important that policy makers continue to strengthen and monitor the implementation of strategies that promote proportionate universalism and forge multi-sectoral approach in dealing with social determinants of inequities in maternal health services coverage.
Maier, Johannes; Knott, Bernadette; Maerz, Manuel; Loeschel, Rainer; Koelbl, Oliver; Dobler, Barbara
2016-08-31
The aim of the study was to compare the two irradiation modes with (FF) and without flattening filter (FFF) for three different treatment techniques for simultaneous integrated boost radiation therapy of patients with right sided breast cancer. An Elekta Synergy linac with Agility collimating device is used to simulate the treatment of 10 patients. Six plans were generated in Monaco 5.0 for each patient treating the whole breast and a simultaneous integrated boost (SIB) volume: intensity modulated radiation therapy (IMRT), volumetric modulated arc therapy (VMAT) and a tangential arc VMAT (tVMAT), each with and without flattening filter. Plan quality was assessed considering target coverage, sparing of the contralateral breast, the lungs, the heart and the normal tissue. All plans were verified by a 2D-ionisation-chamber-array and delivery times were measured and compared. The Wilcoxon test was used for statistical analysis with a significance level of 0.05. Significantly best target coverage and homogeneity was achieved using VMAT FFF with V95% = (98.7 ± 0.8) % and HI = (8.2 ± 0.9) % for the SIB and V95% = (98.3 ± 0.7) % for the PTV, whereas tVMAT showed significantly lowest doses to the contralateral organs at risk with a Dmean of (0.7 ± 0.1) Gy for the contralateral lung, (1.0 ± 0.2) Gy for the contralateral breast and (1.4 ± 0.2) Gy for the heart. All plans passed the gamma evaluation with a mean passing rate of (99.2 ± 0.8) %. Delivery times were significantly reduced for VMAT and tVMAT but increased for IMRT, when FFF was used. Lowest delivery times were observed for tVMAT FFF with (1:20 ± 0:07) min. Balancing target coverage, OAR sparing and delivery time, VMAT FFF and tVMAT FFF are considered the preferable of the investigated treatment options in simultaneous integrated boost irradiation of right sided breast cancer for the combination of an Elekta Synergy linac with Agility and the treatment planning system Monaco 5.0.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Sheng, Y; Li, T; Yoo, S
2016-06-15
Purpose: To enable near-real-time (<20sec) and interactive planning without compromising quality for whole breast RT treatment planning using tangential fields. Methods: Whole breast RT plans from 20 patients treated with single energy (SE, 6MV, 10 patients) or mixed energy (ME, 6/15MV, 10 patients) were randomly selected for model training. Additional 20 cases were used as validation cohort. The planning process for a new case consists of three fully automated steps:1. Energy Selection. A classification model automatically selects energy level. To build the energy selection model, principle component analysis (PCA) was applied to the digital reconstructed radiographs (DRRs) of training casesmore » to extract anatomy-energy relationship.2. Fluence Estimation. Once energy is selected, a random forest (RF) model generates the initial fluence. This model summarizes the relationship between patient anatomy’s shape based features and the output fluence. 3. Fluence Fine-tuning. This step balances the overall dose contribution throughout the whole breast tissue by automatically selecting reference points and applying centrality correction. Fine-tuning works at beamlet-level until the dose distribution meets clinical objectives. Prior to finalization, physicians can also make patient-specific trade-offs between target coverage and high-dose volumes.The proposed method was validated by comparing auto-plans with manually generated clinical-plans using Wilcoxon Signed-Rank test. Results: In 19/20 cases the model suggested the same energy combination as clinical-plans. The target volume coverage V100% was 78.1±4.7% for auto-plans, and 79.3±4.8% for clinical-plans (p=0.12). Volumes receiving 105% Rx were 69.2±78.0cc for auto-plans compared to 83.9±87.2cc for clinical-plans (p=0.13). The mean V10Gy, V20Gy of the ipsilateral lung was 24.4±6.7%, 18.6±6.0% for auto plans and 24.6±6.7%, 18.9±6.1% for clinical-plans (p=0.04, <0.001). Total computational time for auto-plans was < 20s. Conclusion: We developed an automated method that generates breast radiotherapy plans with accurate energy selection, similar target volume coverage, reduced hotspot volumes, and significant reduction in planning time, allowing for near-real-time planning.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Boehling, Nicholas S.; Grosshans, David R., E-mail: dgrossha@mdanderson.org; Bluett, Jaques B.
Purpose: Cranial irradiation in pediatric patients is associated with serious long-term adverse effects. We sought to determine whether both three-dimensional conformal proton radiotherapy (3D-PRT) and intensity-modulated proton therapy (IMPT) compared with intensity-modulated radiotherapy (IMRT) decrease integral dose to brain areas known to harbor neuronal stem cells, major blood vessels, and other normal brain structures for pediatric patients with craniopharyngiomas. Methods and Materials: IMRT, forward planned, passive scattering proton, and IMPT plans were generated and optimized for 10 pediatric patients. The dose was 50.4 Gy (or cobalt Gy equivalent) delivered in 28 fractions with the requirement for planning target volume (PTV)more » coverage of 95% or better. Integral dose data were calculated from differential dose-volume histograms. Results: The PTV target coverage was adequate for all modalities. IMRT and IMPT yielded the most conformal plans in comparison to 3D-PRT. Compared with IMRT, 3D-PRT and IMPT plans had a relative reduction of integral dose to the hippocampus (3D-PRT, 20.4; IMPT, 51.3%{sup Asterisk-Operator }), dentate gyrus (27.3, 75.0%{sup Asterisk-Operator }), and subventricular zone (4.5, 57.8%{sup Asterisk-Operator }). Vascular organs at risk also had reduced integral dose with the use of proton therapy (anterior cerebral arteries, 33.3{sup Asterisk-Operator }, 100.0%{sup Asterisk-Operator }; middle cerebral arteries, 25.9%{sup Asterisk-Operator }, 100%{sup Asterisk-Operator }; anterior communicating arteries, 30.8{sup Asterisk-Operator }, 41.7%{sup Asterisk-Operator }; and carotid arteries, 51.5{sup Asterisk-Operator }, 77.6{sup Asterisk-Operator }). Relative reduction of integral dose to the infratentorial brain (190.7{sup Asterisk-Operator }, 109.7%{sup Asterisk-Operator }), supratentorial brain without PTV (9.6, 26.8%{sup Asterisk-Operator }), brainstem (45.6, 22.4%{sup Asterisk-Operator }), and whole brain without PTV (19.4{sup Asterisk-Operator }, 34.4%{sup Asterisk-Operator }) were recorded with the use of proton therapy. ({sup Asterisk-Operator }Differences were significant based on Friedman's test with Bonferroni-Dunn correction, {alpha} = 0.05) Conclusions: The current study found that proton therapy was able to avoid excess integral radiation dose to a variety of normal structures at all dose levels while maintaining equal target coverage. Future studies will examine the clinical benefits of these dosimetric advantages.« less
Jankowska, Petra J; Kong, Christine; Burke, Kevin; Harrington, Kevin J; Nutting, Christopher
2007-10-01
High dose irradiation of the posterior cervical lymph nodes usually employs applied electron fields to treat the target volume and maintain the spinal cord dose within tolerance. In the light of recent advances in elective lymph node localisation we investigated optimization of field shape and electron energy to treat this target volume. In this study, three sequential hypotheses were tested. Firstly, that customization of the electron fields based on the nodal PTV outlined gives better PTV coverage than conventional field delineation. Using the consensus guidelines, customization of the electron field shape was compared to conventional fields based on bony landmarks. Secondly, that selection of electron energy using DVHs for spinal cord and PTV improves the minimum dose to PTV. Electron dose-volume histograms (DVHs) for the PTV, spinal cord and para-vertebral muscles, were generated using the Monte Carlo electron algorithm. These DVHs were used to compare standard vs optimized electron energy calculations. Finally, that combination of field customization and electron energy optimization improves both the minimum and mean doses to PTV compared with current standard practice. Customized electron beam shaping based on the consensus guidelines led to fewer geographical misses than standard field shaping. Customized electron energy calculation led to higher minimum doses to the PTV. Overall, the customization of field shape and energy resulted in an improved mean dose to the PTV (92% vs 83% p=0.02) and a 27% improvement in the minimum dose delivered to the PTV (45% vs 18% p=0.0009). Optimization of electron field shape and beam energy based on current consensus guidelines led to significant improvement in PTV coverage and may reduce recurrence rates.
A stochastic model for tumor geometry evolution during radiation therapy in cervical cancer
DOE Office of Scientific and Technical Information (OSTI.GOV)
Liu, Yifang; Lee, Chi-Guhn; Chan, Timothy C. Y., E-mail: tcychan@mie.utoronto.ca
2014-02-15
Purpose: To develop mathematical models to predict the evolution of tumor geometry in cervical cancer undergoing radiation therapy. Methods: The authors develop two mathematical models to estimate tumor geometry change: a Markov model and an isomorphic shrinkage model. The Markov model describes tumor evolution by investigating the change in state (either tumor or nontumor) of voxels on the tumor surface. It assumes that the evolution follows a Markov process. Transition probabilities are obtained using maximum likelihood estimation and depend on the states of neighboring voxels. The isomorphic shrinkage model describes tumor shrinkage or growth in terms of layers of voxelsmore » on the tumor surface, instead of modeling individual voxels. The two proposed models were applied to data from 29 cervical cancer patients treated at Princess Margaret Cancer Centre and then compared to a constant volume approach. Model performance was measured using sensitivity and specificity. Results: The Markov model outperformed both the isomorphic shrinkage and constant volume models in terms of the trade-off between sensitivity (target coverage) and specificity (normal tissue sparing). Generally, the Markov model achieved a few percentage points in improvement in either sensitivity or specificity compared to the other models. The isomorphic shrinkage model was comparable to the Markov approach under certain parameter settings. Convex tumor shapes were easier to predict. Conclusions: By modeling tumor geometry change at the voxel level using a probabilistic model, improvements in target coverage and normal tissue sparing are possible. Our Markov model is flexible and has tunable parameters to adjust model performance to meet a range of criteria. Such a model may support the development of an adaptive paradigm for radiation therapy of cervical cancer.« less
Iridium-Knife: Another knife in radiation oncology.
Milickovic, Natasa; Tselis, Nikolaos; Karagiannis, Efstratios; Ferentinos, Konstantinos; Zamboglou, Nikolaos
Intratarget dose escalation with superior conformity is a defining feature of three-dimensional (3D) iridium-192 ( 192 Ir) high-dose-rate (HDR) brachytherapy (BRT). In this study, we analyzed the dosimetric characteristics of interstitial 192 Ir HDR BRT for intrathoracic and cerebral malignancies. We examined the dose gradient sharpness of HDR BRT compared with that of linear accelerator-based stereotactic radiosurgery and stereotactic body radiation therapy, usually called X-Knife, to demonstrate that it may as well be called a Knife. Treatment plans for 10 patients with recurrent glioblastoma multiforme or intrathoracic malignancies, five of each entity, treated with X-Knife (stereotactic radiosurgery for glioblastoma multiforme and stereotactic body radiation therapy for intrathoracic malignancies) were replanned for simulated HDR BRT. For 3D BRT planning, we used identical structure sets and dose prescription as for the X-Knife planning. The indices for qualitative treatment plan analysis encompassed planning target volume coverage, conformity, dose falloff gradient, and the maximum dose-volume limits to different organs at risk. Volume coverage in HDR plans was comparable to that calculated for X-Knife plans with no statistically significant difference in terms of conformity. The dose falloff gradient-sharpness-of the HDR plans was considerably steeper compared with the X-Knife plans. Both 3D 192 Ir HDR BRT and X-Knife are effective means for intratarget dose escalation with HDR BRT achieving at least equal conformity and a steeper dose falloff at the target volume margin. In this sense, it can reasonably be argued that 3D 192 Ir HDR BRT deserves also to be called a Knife, namely Iridium-Knife. Copyright © 2017 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.
Sripathi, Lalitha Kameshwari; Ahlawat, Parveen; Simson, David K; Khadanga, Chira Ranjan; Kamarsu, Lakshmipathi; Surana, Shital Kumar; Arasu, Kavi; Singh, Harpreet
2017-01-01
Different techniques of radiation therapy have been studied to reduce the cardiac dose in left breast cancer. In this prospective dosimetric study, the doses to heart as well as other organs at risk (OAR) were compared between free-breathing (FB) and deep inspiratory breath hold (DIBH) techniques in intensity modulated radiotherapy (IMRT) and opposed-tangent three-dimensional radiotherapy (3DCRT) plans. Fifteen patients with left-sided breast cancer underwent computed tomography simulation and images were obtained in both FB and DIBH. Radiotherapy plans were generated with 3DCRT and IMRT techniques in FB and DIBH images in each patient. Target coverage, conformity index, homogeneity index, and mean dose to heart (Heart D mean ), left lung, left anterior descending artery (LAD) and right breast were compared between the four plans using the Wilcoxon signed rank test. Target coverage was adequate with both 3DCRT and IMRT plans, but IMRT plans showed better conformity and homogeneity. A statistically significant dose reduction of all OARs was found with DIBH. 3DCRT DIBH decreased the Heart D mean by 53.5% (7.1 vs. 3.3 Gy) and mean dose to LAD by 28% compared to 3DCRT FB . IMRT further lowered mean LAD dose by 18%. Heart D mean was lower with 3DCRT DIBH over IMRT DIBH (3.3 vs. 10.2 Gy). Mean dose to the contralateral breast was also lower with 3DCRT over IMRT (0.32 vs. 3.35 Gy). Mean dose and the V 20 of ipsilateral lung were lower with 3DCRT DIBH over IMRT DIBH (13.78 vs. 18.9 Gy) and (25.16 vs. 32.95%), respectively. 3DCRT DIBH provided excellent dosimetric results in patients with left-sided breast cancer without the need for IMRT.
Sripathi, Lalitha Kameshwari; Ahlawat, Parveen; Simson, David K; Khadanga, Chira Ranjan; Kamarsu, Lakshmipathi; Surana, Shital Kumar; Arasu, Kavi; Singh, Harpreet
2017-01-01
Introduction: Different techniques of radiation therapy have been studied to reduce the cardiac dose in left breast cancer. Aim: In this prospective dosimetric study, the doses to heart as well as other organs at risk (OAR) were compared between free-breathing (FB) and deep inspiratory breath hold (DIBH) techniques in intensity modulated radiotherapy (IMRT) and opposed-tangent three-dimensional radiotherapy (3DCRT) plans. Materials and Methods: Fifteen patients with left-sided breast cancer underwent computed tomography simulation and images were obtained in both FB and DIBH. Radiotherapy plans were generated with 3DCRT and IMRT techniques in FB and DIBH images in each patient. Target coverage, conformity index, homogeneity index, and mean dose to heart (Heart Dmean), left lung, left anterior descending artery (LAD) and right breast were compared between the four plans using the Wilcoxon signed rank test. Results: Target coverage was adequate with both 3DCRT and IMRT plans, but IMRT plans showed better conformity and homogeneity. A statistically significant dose reduction of all OARs was found with DIBH. 3DCRTDIBH decreased the Heart Dmean by 53.5% (7.1 vs. 3.3 Gy) and mean dose to LAD by 28% compared to 3DCRTFB. IMRT further lowered mean LAD dose by 18%. Heart Dmean was lower with 3DCRTDIBH over IMRTDIBH (3.3 vs. 10.2 Gy). Mean dose to the contralateral breast was also lower with 3DCRT over IMRT (0.32 vs. 3.35 Gy). Mean dose and the V20 of ipsilateral lung were lower with 3DCRTDIBH over IMRTDIBH (13.78 vs. 18.9 Gy) and (25.16 vs. 32.95%), respectively. Conclusions: 3DCRTDIBH provided excellent dosimetric results in patients with left-sided breast cancer without the need for IMRT. PMID:28974856
Wong, Wicger; Leung, Lucullus H.T.; Yu, Peter K.N.; So, Ronald W.K.; Cheng, Ashley C.K.
2012-01-01
The purpose of this study was to investigate the potential benefits of using triple‐arc volumetric‐intensity modulated arc radiotherapy (RapidArc (RA)) for the treatment of early‐stage nasopharyngeal carcinoma (NPC). A comprehensive evaluation was performed including plan quality, integral doses, and peripheral doses. Twenty cases of stage I or II NPC were selected for this study. Nine‐field sliding window IMRT, double‐arc, and triple‐arc RA treatment plans were compared with respect to target coverage, dose conformity, critical organ sparing, and integral doses. Measurement of peripheral doses was performed using thermoluminescent dosimeters in an anthropomorphic phantom. While similar conformity and target coverage were achieved by the three types of plans, triple‐arc RA produced better sparing of parotid glands and spinal cord than double‐arc RA or IMRT. Double‐arc RA plans produced slightly inferior parotid sparing and dose homogeneity than the other two delivery methods. The monitor units (MU) required for triple‐arc were about 50% less than those of IMRT plans, while there was no significant difference in the required MUs between triple‐arc and double‐arc RA plans. The peripheral dose in triple‐arc RA was found to be 50% less compared to IMRT near abdominal and pelvic region. Triple‐arc RA improves both the plan quality and treatment efficiency compared with IMRT for the treatment of early stage NPC. It has become the preferred choice of treatment delivery method for early stage NPC at our center. PACS numbers: 87.53.Bn, 87.55.D, 87.55.de, 87.55.dk, 87.56.ng PMID:23149781
DOE Office of Scientific and Technical Information (OSTI.GOV)
Qiao, L; Deng, G; Xie, J
2015-06-15
Purpose: To compare the dosimetric characteristics of volumetric-modulated arc therapy (VMAT) and intensity-modulated radiotherapy (IMRT) techniques in treatment planning for left-sided breast cancer patients with modified radical mastectomy. Methods: Twenty-four left-sided breast cancer patients treated with modified radical mastectomy were selected in this study. The planning target volume (PTV) was generated by using 7-mm uniform expansion of the clinical target volume (CTV) in all direction except the skin surface. The organs at risk (OARs) included heart, left lung, right lung, and right breast. Dose volume histograms (DVHs) were utilized to evaluate the dose distribution in PTV and OARs. Results: Bothmore » VMAT and IMRT plans met the requirement of PTV coverage. VMAT was superior to IMRT in terms of conformity, with a statistically significant difference (p=0.024). Mean doses, V5 and V10 of heart and both lungs in VMAT plans were significantly decreased compared to IMRT plans (P<0.05), but in terms of heart volume irradiated by high doses (V30 and V45), no significant differences were observed (P>0.05). For right breast, VMAT showed the reduction of V5 in comparison with IMRT (P<0.05). Additionally, the mean number of monitor units (MU) and treatment time in VMAT (357.21, 3.62 min) were significantly less than those in IMRT (1132.85, 8.74 min). Conclusion: VMAT showed similar PTV coverage and significant advantage in OARs sparing compared with IMRT, especially in terms of decreased volumes irradiated by low doses, while significantly reducing the treatment time and MU number.« less
Total dural irradiation: RapidArc versus static-field IMRT: A case study
DOE Office of Scientific and Technical Information (OSTI.GOV)
Kelly, Paul J., E-mail: paulj.kelly@hse.ie; Mannarino, Edward; Lewis, John Henry
2012-07-01
The purpose of this study was to compare conventional fixed-gantry angle intensity-modulated radiation therapy (IMRT) with RapidArc for total dural irradiation. We also hypothesize that target volume-individualized collimator angles may produce substantial normal tissue sparing when planning with RapidArc. Five-, 7-, and 9-field fixed-gantry angle sliding-window IMRT plans were generated for comparison with RapidArc plans. Optimization and normal tissue constraints were constant for all plans. All plans were normalized so that 95% of the planning target volume (PTV) received at least 100% of the dose. RapidArc was delivered using 350 Degree-Sign clockwise and counterclockwise arcs. Conventional collimator angles of 45more » Degree-Sign and 315 Degree-Sign were compared with 90 Degree-Sign on both arcs. Dose prescription was 59.4 Gy in 33 fractions. PTV metrics used for comparison were coverage, V{sub 107}%, D1%, conformality index (CI{sub 95}%), and heterogeneity index (D{sub 5}%-D{sub 95}%). Brain dose, the main challenge of this case, was compared using D{sub 1}%, Dmean, and V{sub 5} Gy. Dose to optic chiasm, optic nerves, globes, and lenses was also compared. The use of unconventional collimator angles (90 Degree-Sign on both arcs) substantially reduced dose to normal brain. All plans achieved acceptable target coverage. Homogeneity was similar for RapidArc and 9-field IMRT plans. However, heterogeneity increased with decreasing number of IMRT fields, resulting in unacceptable hotspots within the brain. Conformality was marginally better with RapidArc relative to IMRT. Low dose to brain, as indicated by V5Gy, was comparable in all plans. Doses to organs at risk (OARs) showed no clinically meaningful differences. The number of monitor units was lower and delivery time was reduced with RapidArc. The case-individualized RapidArc plan compared favorably with the 9-field conventional IMRT plan. In view of lower monitor unit requirements and shorter delivery time, RapidArc was selected as the optimal solution. Individualized collimator angle solutions should be considered by RapidArc dosimetrists for OARs dose reduction. RapidArc should be considered as a treatment modality for tumors that extensively involve in the skull, dura, or scalp.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Moteabbed, M; Depauw, N; Kooy, H
Purpose: To investigate the dosimetric benefits of pencil beam scanning (PBS) compared with passive scattered (PS) proton therapy for treatment of pediatric head&neck patients as a function of the PBS spot size and explore the advantages of using apertures in PBS. Methods: Ten pediatric patients with head&neck cancers treated by PS proton therapy at our institution were retrospectively selected. The histologies included rhabdomyosarcoma, ependymoma, astrocytoma, craniopharyngioma and germinoma. The prescribed dose ranged from 36 to 54 Gy(RBE). Five PBS plans were created for each patient using variable spot size (average sigma at isocenter) and choice of beam specific apertures: (1)more » 10mm spots, (2) 10mm spots with apertures, (3) 6mm spots, (4) 6mm spots with apertures, and (5) 3mm spots. The plans were optimized for intensity modulated proton therapy (IMPT) with no single beam uniformity constraints. Dose volume indices as well as equivalent uniform dose (EUD) were compared between PS and PBS plans. Results: Although target coverage was clinically adequate for all cases, the plans with largest (10mm) spots provide inferior quality compared with PS in terms of dose to organs-at-risk (OAR). However, adding apertures to these plans ensured lower OAR dose than PS. The average EUD difference between PBS and PS plans over all patients and organs at risk were (1) 2.5%, (2) −5.1%, (3) -5%, (4) −7.8%, and (5) −9.5%. As the spot size decreased, more conformal plans were achieved that offered similar target coverage but lower dose to the neighboring healthy organs, while alleviating the need for using apertures. Conclusion: The application of PBS does not always translate to better plan qualities compared to PS depending on the available beam spot size. We recommend that institutions with spot size larger than ∼6mm at isocenter consider using apertures to guarantee clinically comparable or superior dosimetric efficacy to PS treatments.« less
Routinely vaccinating adolescents against meningococcus: targeting transmission & disease
Vetter, Volker; Baxter, Roger; Denizer, Gülhan; Sáfadi, Marco A. P.; Silfverdal, Sven-Arne; Vyse, Andrew; Borrow, Ray
2016-01-01
ABSTRACT Adolescents have the highest rates of meningococcal carriage and transmission. Interrupting the adolescent habitat in order to reduce carriage and transmission within adolescents and to other age groups could help to control meningococcal disease at a population level. Compared to immunization strategies restricted to young children, a strategy focused on adolescents may have more profound and long-lasting indirect impacts, and may be more cost effective. Despite challenges in reaching this age-group, experience with other vaccines show that high vaccine coverage of adolescents is attainable. PMID:26651380
Cha, Seungman; Mankadi, Paul Mansiangi; Elhag, Mousab Siddig; Lee, Yongjoo; Jin, Yan
2017-01-01
ABSTRACT Background: As the Millennium Development Goals ended, and were replaced by the Sustainable Development Goals, efforts have been made to evaluate the achievements and performance of official development assistance (ODA) in the health sector. In this study, we explore trends in the expansion of water and sanitation coverage in developing countries and the performance of ODA. Design: We explored inequality across developing countries by income level, and investigated how ODA for water and sanitation was committed by country, region, and income level. Changes in inequality were tested via slope changes by investigating the interaction of year and income level with a likelihood ratio test. A random effects model was applied according to the results of the Hausman test. Results: The slope of the linear trend between economic level and sanitation coverage has declined over time. However, a random effects model suggested that the change in slope across years was not significant (e.g. for the slope change between 2000 and 2010: likelihood ratio χ2 = 2.49, probability > χ2 = 0.1146). A similar pro-rich pattern across developing countries and a non-significant change in the slope associated with different economic levels were demonstrated for water coverage. Our analysis shows that the inequality of water and sanitation coverage among countries across the world has not been addressed effectively during the past decade. Our findings demonstrate that the countries with the least coverage persistently received far less ODA per capita than did countries with much more extensive water and sanitation coverage, suggesting that ODA for water and sanitation is poorly targeted. Conclusion: The most deprived countries should receive more attention for water and sanitation improvements from the world health community. A strong political commitment to ODA targeting the countries with the least coverage is needed at the global level. PMID:28604256
Dai, Yifei; Scuderi, Giles R; Bischoff, Jeffrey E; Bertin, Kim; Tarabichi, Samih; Rajgopal, Ashok
2014-12-01
The aim of this study was to comprehensively evaluate contemporary tibial component designs against global tibial anatomy. We hypothesized that anatomically designed tibial components offer increased morphological fit to the resected proximal tibia with increased alignment accuracy compared to symmetric and asymmetric designs. Using a multi-ethnic bone dataset, six contemporary tibial component designs were investigated, including anatomic, asymmetric, and symmetric design types. Investigations included (1) measurement of component conformity to the resected tibia using a comprehensive set of size and shape metrics; (2) assessment of component coverage on the resected tibia while ensuring clinically acceptable levels of rotation and overhang; and (3) evaluation of the incidence and severity of component downsizing due to adherence to rotational alignment and overhang requirements, and the associated compromise in tibial coverage. Differences in coverage were statistically compared across designs and ethnicities, as well as between placements with or without enforcement of proper rotational alignment. Compared to non-anatomic designs investigated, the anatomic design exhibited better conformity to resected tibial morphology in size and shape, higher tibial coverage (92% compared to 85-87%), more cortical support (posteromedial region), lower incidence of downsizing (3% compared to 39-60%), and less compromise of tibial coverage (0.5% compared to 4-6%) when enforcing proper rotational alignment. The anatomic design demonstrated meaningful increase in tibial coverage with accurate rotational alignment compared to symmetric and asymmetric designs, suggesting its potential for less intra-operative compromises and improved performance. III.
Range optimization for mono- and bi-energetic proton modulated arc therapy with pencil beam scanning
NASA Astrophysics Data System (ADS)
Sanchez-Parcerisa, Daniel; Kirk, Maura; Fager, Marcus; Burgdorf, Brendan; Stowe, Malorie; Solberg, Tim; Carabe, Alejandro
2016-11-01
The development of rotational proton therapy plans based on a pencil-beam-scanning (PBS) system has been limited, among several other factors, by the energy-switching time between layers, a system-dependent parameter that ranges between a fraction of a second and several seconds. We are investigating mono- and bi-energetic rotational proton modulated arc therapy (PMAT) solutions that would not be affected by long energy switching times. In this context, a systematic selection of the optimal proton energy for each arc is vital. We present a treatment planning comparison of four different range selection methods, analyzing the dosimetric outcomes of the resulting treatment plans created with the ranges obtained. Given the patient geometry and arc definition (gantry and couch trajectories, snout elevation) our in-house treatment planning system (TPS) FoCa was used to find the maximum, medial and minimum water-equivalent thicknesses (WETs) of the target viewed from all possible field orientations. Optimal ranges were subsequently determined using four methods: (1) by dividing the max/min WET interval into equal steps, (2) by taking the average target midpoints from each field, (3) by taking the average WET of all voxels from all field orientations, and (4) by minimizing the fraction of the target which cannot be reached from any of the available angles. After the range (for mono-energetic plans) or ranges (for bi-energetic plans) were selected, the commercial clinical TPS in use in our institution (Varian Eclipse™) was used to produce the PMAT plans using multifield optimization. Linear energy transfer (LET) distributions of all plans were also calculated using FoCa and compared among the different methods. Mono- and bi-energetic PMAT plans, composed of a single 180° arc, were created for two patient geometries: a C-shaped target located in the mediastinal area of a thoracic tissue-equivalent phantom and a small brain tumor located directly above the brainstem. All plans were optimized using the same procedure to (1) achieve target coverage, (2) reduce dose to OAR and (3) limit dose hot spots in the target. Final outcomes were compared in terms of the resulting dose and LET distributions. Data shows little significant differences among the four studied methods, with superior results obtained with mono-energetic plans. A streamlined systematic method has been implemented in an in-house TPS to find the optimal range to maximize target coverage with rotational mono- or bi-energetic PBS rotational plans by minimizing the fraction of the target that cannot be reached by any direction.
Wehby, George L; Lyu, Wei
2018-04-01
Examine the ACA Medicaid expansion effects on Medicaid take-up and private coverage through 2015 and coverage disparities by age, race/ethnicity, and gender. 2011-2015 American Community Survey for 3,137,989 low-educated adults aged 19-64 years. Difference-in-differences regressions accounting for national coverage trends and state fixed effects. Expansion effects doubled in 2015 among low-educated adults, with a nearly 8 percentage-point increase in Medicaid take-up and 6 percentage-point decline in uninsured rate. Significant coverage gains were observed across virtually all examined groups by age, gender, and race/ethnicity. Take-up and insurance declines were strongest among younger adults and were generally close by gender and race/ethnicity. Despite the increased take-up however, coverage disparities remained sizeable, especially for young adults and Hispanics who had declining but still high uninsured rates in 2015. There was some evidence of private coverage crowd-out in certain subgroups, particularly among young adults aged 19-26 years and women, including in both individually purchased and employer-sponsored coverage. The ACA Medicaid expansions have continued to increase coverage in 2015 across the entire population of low-educated adults and have reduced age disparities in coverage. However, there is still a need for interventions that target eligible young and Hispanic adults. © Health Research and Educational Trust.
Probabilistic objective functions for margin-less IMRT planning
NASA Astrophysics Data System (ADS)
Bohoslavsky, Román; Witte, Marnix G.; Janssen, Tomas M.; van Herk, Marcel
2013-06-01
We present a method to implement probabilistic treatment planning of intensity-modulated radiation therapy using custom software plugins in a commercial treatment planning system. Our method avoids the definition of safety-margins by directly including the effect of geometrical uncertainties during optimization when objective functions are evaluated. Because the shape of the resulting dose distribution implicitly defines the robustness of the plan, the optimizer has much more flexibility than with a margin-based approach. We expect that this added flexibility helps to automatically strike a better balance between target coverage and dose reduction for surrounding healthy tissue, especially for cases where the planning target volume overlaps organs at risk. Prostate cancer treatment planning was chosen to develop our method, including a novel technique to include rotational uncertainties. Based on population statistics, translations and rotations are simulated independently following a marker-based IGRT correction strategy. The effects of random and systematic errors are incorporated by first blurring and then shifting the dose distribution with respect to the clinical target volume. For simplicity and efficiency, dose-shift invariance and a rigid-body approximation are assumed. Three prostate cases were replanned using our probabilistic objective functions. To compare clinical and probabilistic plans, an evaluation tool was used that explicitly incorporates geometric uncertainties using Monte-Carlo methods. The new plans achieved similar or better dose distributions than the original clinical plans in terms of expected target coverage and rectum wall sparing. Plan optimization times were only about a factor of two higher than in the original clinical system. In conclusion, we have developed a practical planning tool that enables margin-less probability-based treatment planning with acceptable planning times, achieving the first system that is feasible for clinical implementation.
Fogliata, Antonella; Scorsetti, Marta; Navarria, Piera; Catalano, Maddalena; Clivio, Alessandro; Cozzi, Luca; Lobefalo, Francesca; Nicolini, Giorgia; Palumbo, Valentina; Pellegrini, Chiara; Reggiori, Giacomo; Roggio, Antonella; Vanetti, Eugenio; Alongi, Filippo; Pentimalli, Sara; Mancosu, Pietro
2013-04-01
To appraise the potential of volumetric modulated arc therapy (VMAT, RapidArc) and proton beams to simultaneously achieve target coverage and enhanced sparing of bone tissue in the treatment of soft-tissue sarcoma with adequate target coverage. Ten patients presenting with soft-tissue sarcoma of the leg were collected for the study. Dose was prescribed to 66.5 Gy in 25 fractions to the planning target volume (PTV) while significant maximum dose to the bone was constrained to 50 Gy. Plans were optimised according to the RapidArc technique with 6 MV photon beams or for intensity modulated protons. RapidArc photon plans were computed with: 1) AAA; 2) Acuros XB as dose to medium; and 3) Acuros XB as dose to water. All plans acceptably met the criteria of target coverage (V95% >90-95%) and bone sparing (D(1 cm3) <50 Gy). Significantly higher PTV dose homogeneity was found for proton plans. Near-to-maximum dose to bone was similar for RapidArc and protons, while volume receiving medium/low dose levels was minimised with protons. Similar results were obtained for the remaining normal tissue. Dose distributions calculated with the dose to water option resulted ~5% higher than corresponding ones computed as dose to medium. High plan quality was demonstrated for both VMAT and proton techniques when applied to soft-tissue sarcoma.
Burnum-Johnson, Kristin E; Nie, Song; Casey, Cameron P; Monroe, Matthew E; Orton, Daniel J; Ibrahim, Yehia M; Gritsenko, Marina A; Clauss, Therese R W; Shukla, Anil K; Moore, Ronald J; Purvine, Samuel O; Shi, Tujin; Qian, Weijun; Liu, Tao; Baker, Erin S; Smith, Richard D
2016-12-01
Current proteomic approaches include both broad discovery measurements and quantitative targeted analyses. In many cases, discovery measurements are initially used to identify potentially important proteins (e.g. candidate biomarkers) and then targeted studies are employed to quantify a limited number of selected proteins. Both approaches, however, suffer from limitations. Discovery measurements aim to sample the whole proteome but have lower sensitivity, accuracy, and quantitation precision than targeted approaches, whereas targeted measurements are significantly more sensitive but only sample a limited portion of the proteome. Herein, we describe a new approach that performs both discovery and targeted monitoring (DTM) in a single analysis by combining liquid chromatography, ion mobility spectrometry and mass spectrometry (LC-IMS-MS). In DTM, heavy labeled target peptides are spiked into tryptic digests and both the labeled and unlabeled peptides are detected using LC-IMS-MS instrumentation. Compared with the broad LC-MS discovery measurements, DTM yields greater peptide/protein coverage and detects lower abundance species. DTM also achieved detection limits similar to selected reaction monitoring (SRM) indicating its potential for combined high quality discovery and targeted analyses, which is a significant step toward the convergence of discovery and targeted approaches. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Shi, Chengyu, E-mail: shicy1974@yahoo.com; Chen, Yong; Fang, Deborah
2015-04-01
Liver stereotactic body radiation therapy (SBRT) is a feasible treatment method for the nonoperable, patient with early-stage liver cancer. Treatment planning for the SBRT is very important and has to consider the simulation accuracy, planning time, treatment efficiency effects etc. The modified dynamic conformal arc (MDCA) technique is a 3-dimensional conformal arc planning method, which has been proposed for liver SBRT planning at our center. In this study, we compared the MDCA technique with the RapidArc technique in terms of planning target volume (PTV) coverage and sparing of organs at risk (OARs). The results show that the MDCA technique hasmore » comparable plan quality to RapidArc considering PTV coverage, hot spots, heterogeneity index, and effective liver volume. For the 5 PTVs studied among 4 patients, the MDCA plan, when compared with the RapidArc plan, showed 9% more hot spots, more heterogeneity effect, more sparing of OARs, and lower liver effective volume. The monitor unit (MU) number for the MDCA plan is much lower than for the RapidArc plans. The MDCA plan has the advantages of less planning time, no-collision treatment, and a lower MU number.« less
Costs and consequences of large-scale vector control for malaria
Yukich, Joshua O; Lengeler, Christian; Tediosi, Fabrizio; Brown, Nick; Mulligan, Jo-Ann; Chavasse, Des; Stevens, Warren; Justino, John; Conteh, Lesong; Maharaj, Rajendra; Erskine, Marcy; Mueller, Dirk H; Wiseman, Virginia; Ghebremeskel, Tewolde; Zerom, Mehari; Goodman, Catherine; McGuire, David; Urrutia, Juan Manuel; Sakho, Fana; Hanson, Kara; Sharp, Brian
2008-01-01
Background Five large insecticide-treated net (ITN) programmes and two indoor residual spraying (IRS) programmes were compared using a standardized costing methodology. Methods Costs were measured locally or derived from existing studies and focused on the provider perspective, but included the direct costs of net purchases by users, and are reported in 2005 USD. Effectiveness was estimated by combining programme outputs with standard impact indicators. Findings Conventional ITNs: The cost per treated net-year of protection ranged from USD 1.21 in Eritrea to USD 6.05 in Senegal. The cost per child death averted ranged from USD 438 to USD 2,199 when targeting to children was successful. Long-lasting insecticidal nets (LLIN) of five years duration: The cost per treated-net year of protection ranged from USD 1.38 in Eritrea to USD 1.90 in Togo. The cost per child death averted ranged from USD 502 to USD 692. IRS: The costs per person-year of protection for all ages were USD 3.27 in KwaZulu Natal and USD 3.90 in Mozambique. If only children under five years of age were included in the denominator the cost per person-year of protection was higher: USD 23.96 and USD 21.63. As a result, the cost per child death averted was higher than for ITNs: USD 3,933–4,357. Conclusion Both ITNs and IRS are highly cost-effective vector control strategies. Integrated ITN free distribution campaigns appeared to be the most efficient way to rapidly increase ITN coverage. Other approaches were as or more cost-effective, and appeared better suited to "keep-up" coverage levels. ITNs are more cost-effective than IRS for highly endemic settings, especially if high ITN coverage can be achieved with some demographic targeting. PMID:19091114
DOE Office of Scientific and Technical Information (OSTI.GOV)
Dellamonica, D.; Luo, G.; Ding, G.
Purpose: Setup errors on the order of millimeters may cause under-dosing of targets and significant changes in dose to critical structures especially when planning with tight margins in stereotactic radiosurgery. This study evaluates the effects of these types of patient positioning uncertainties on planning target volume (PTV) coverage and cochlear dose for stereotactic treatments of acoustic neuromas. Methods: Twelve acoustic neuroma patient treatment plans were retrospectively evaluated in Brainlab iPlan RT Dose 4.1.3. All treatment beams were shaped by HDMLC from a Varian TX machine. Seven patients had planning margins of 2mm, five had 1–1.5mm. Six treatment plans were createdmore » for each patient simulating a 1mm setup error in six possible directions: anterior-posterior, lateral, and superiorinferior. The arcs and HDMLC shapes were kept the same for each plan. Change in PTV coverage and mean dose to the cochlea was evaluated for each plan. Results: The average change in PTV coverage for the 72 simulated plans was −1.7% (range: −5 to +1.1%). The largest average change in coverage was observed for shifts in the patient's superior direction (−2.9%). The change in mean cochlear dose was highly dependent upon the direction of the shift. Shifts in the anterior and superior direction resulted in an average increase in dose of 13.5 and 3.8%, respectively, while shifts in the posterior and inferior direction resulted in an average decrease in dose of 17.9 and 10.2%. The average change in dose to the cochlea was 13.9% (range: 1.4 to 48.6%). No difference was observed based on the size of the planning margin. Conclusion: This study indicates that if the positioning uncertainty is kept within 1mm the setup errors may not result in significant under-dosing of the acoustic neuroma target volumes. However, the change in mean cochlear dose is highly dependent upon the direction of the shift.« less
Shrestha, Sourya; Chihota, Violet; White, Richard G; Grant, Alison D; Churchyard, Gavin J; Dowdy, David W
2017-12-15
Optimizing the use of new tools, such as vaccines, may play a crucial role in reaching global targets for tuberculosis (TB) control. Some of the most promising candidate vaccines target adults, although high-coverage mass vaccinations may be logistically more challenging among this population than among children. Vaccine-delivery strategies that target high-risk groups or settings might yield proportionally greater impact than do those that target the general population. We developed an individual-based TB transmission model representing a hypothetical population consisting of people who worked in South African gold mines or lived in associated labor-sending communities. We simulated the implementation of a postinfection adult vaccine with 60% efficacy and a mean effect duration of 10 years. We then compared the impact of a mine-targeted vaccination strategy, in which miners were vaccinated while in the mines, with that of a community-targeted strategy, in which random individuals within the labor-sending communities were vaccinated. Mine-targeted vaccination averted an estimated 0.37 TB cases per vaccine dose compared with 0.25 for community-targeted vaccination, for a relative efficacy of 1.46 (95% range, 1.13-1.91). The added benefit of mine-targeted vaccination primarily reflected the disproportionate demographic burden of TB among the population of adult males as a whole. As novel vaccines for TB are developed, venue-based vaccine delivery that targets high-risk demographic groups may improve both vaccine feasibility and the impact on transmission. © The Author(s) 2017. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.
Nájera-Aguilar, P; Infante-Castañeda, C
1990-01-01
Less than a third of the non-insured population studied through a sample in the State of Mexico was covered by the Institute of Health of the State of México. This low coverage was observed in spite the fact that health services were available within 2 kilometer radius. 33 per cent of the non-insured preferred to utilize other services within their own community, and 24 per cent of them traveled to bigger localities to receive care. These results suggest that to attain adequate coverage, utilization patterns should be investigated so that health services can meet the needs of the target population.
DOE Office of Scientific and Technical Information (OSTI.GOV)
An, Y; Bues, M; Schild, S
Purpose: We propose to apply a robust optimization model based on fuzzy-logic constraints in the intensity-modulated proton therapy (IMPT) planning subject to range and patient setup uncertainties. The purpose is to ensure the plan robustness under uncertainty and obtain the best trade-off between tumor dose coverage and organ-at-risk(OAR) sparing. Methods: Two IMPT plans were generated for 3 head-and-neck cancer patients: one used the planning target volume(PTV) method; the other used the fuzzy robust optimization method. In the latter method, nine dose distributions were computed - the nominal one and one each for ±3mm setup uncertainties along three cardinal axes andmore » for ±3.5% range uncertainty. For tumors, these nine dose distributions were explicitly controlled by adding hard constraints with adjustable parameters. For OARs, fuzzy constraints that allow the dose to vary within a certain range were used so that the tumor dose distribution was guaranteed by minimum compromise of that of OARs. We rendered this model tractable by converting the fuzzy constraints to linear constraints. The plan quality was evaluated using dose-volume histogram(DVH) indices such as tumor dose coverage(D95%), homogeneity(D5%-D95%), plan robustness(DVH band at D95%), and OAR sparing like D1% of brain and D1% of brainstem. Results: Our model could yield clinically acceptable plans. The fuzzy-logic robust optimization method produced IMPT plans with comparable target dose coverage and homogeneity compared to the PTV method(unit: Gy[RBE]; average[min, max])(CTV D95%: 59 [52.7, 63.5] vs 53.5[46.4, 60.1], CTV D5% - D95%: 11.1[5.3, 18.6] vs 14.4[9.2, 21.5]). It also generated more robust plans(CTV DVH band at D95%: 3.8[1.2, 5.6] vs 11.5[6.2, 16.7]). The parameters of tumor constraints could be adjusted to control the tradeoff between tumor coverage and OAR sparing. Conclusion: The fuzzy-logic robust optimization generates superior IMPT with minimum compromise of OAR sparing. This research was supported by the National Cancer Institute Career Developmental Award K25CA168984, by the Fraternal Order of Eagles Cancer Research Fund Career Development Award, by The Lawrence W. and Marilyn W. Matteson Fund for Cancer Research, by Mayo Arizona State University Seed Grant, and by The Kemper Marley Foundation. eRA Person ID(s) for the Principal Investigator: 11017970 (Research Supported by National Institutes of Health)« less
Value for money: protecting endangered species on Danish heathland.
Strange, Niels; Jacobsen, Jette B; Thorsen, Bo J; Tarp, Peter
2007-11-01
Biodiversity policies in the European Union (EU) are mainly implemented through the Birds and Habitats Directives as well as the establishment of Natura 2000, a network of protected areas throughout the EU. Considerable resources must be allocated for fulfilling the Directives and the question of optimal allocation is as important as it is difficult. In general, economic evaluations of conservation targets at most consider the costs and seldom the welfare economic benefits. In the present study, we use welfare economic benefit estimates concerning the willingness-to-pay for preserving endangered species and for the aggregate area of heathland preserved in Denmark. Similarly, we obtain estimates of the welfare economic cost of habitat restoration and maintenance. Combining these welfare economic measures with expected species coverage, we are able to estimate the potential welfare economic contribution of a conservation network. We compare three simple nonprobabilistic strategies likely to be used in day-to-day policy implementation: i) a maximum selected area strategy, ii) a hotspot selection strategy, and iii) a minimizing cost strategy, and two more advanced and informed probabilistic strategies: i) a maximum expected coverage strategy and ii) a strategy for maximum expected welfare economic gain. We show that the welfare economic performance of the strategies differ considerably. The comparison between the expected coverage and expected welfare shows that for the case considered, one may identify an optimal protection level above which additional coverage only comes at increasing welfare economic loss.
Imran, Hafsa; Raja, Dania; Grassly, Nicholas C; Wadood, M Zubair; Safdar, Rana M; O’Reilly, Kathleen M
2018-01-01
Abstract Background Within Pakistan, estimates of vaccination coverage with the pentavalent vaccine, oral polio vaccine (OPV) and measles vaccine (MV) in 2011 were reported to be 74%, 75% and 53%, respectively. These national estimates may mask regional variation. The reasons for this variation have not been explored. Methods Data from the Multiple Indicator Cluster Surveys (MICS) for Balochistan and Punjab (2010–2011) are analysed to examine factors associated with receiving three or more doses of the pentavalent vaccine and one or more MVs using regression modelling. Pentavalent and OPV estimates from the MICS were compared to vaccine dose histories from surveillance for acute flaccid paralysis (AFP; poliomyelitis) to ascertain agreement. Results Adjusted coverage of children 12–23 months of age were estimated to be 16.0%, 75.5% and 34.2% in Balochistan and 58.0%, 87.7% and 72.6% in Punjab for the pentavalent vaccine, OPV and MV, respectively. Maternal education, healthcare utilization and wealth were associated with receiving the pentavalent vaccine and the MV. There was a strong correlation of district estimates of vaccination coverage between AFP and MICS data, but AFP estimates of pentavalent coverage in Punjab were biased toward higher values. Conclusions National estimates mask variation and estimates from individual surveys should be considered alongside other estimates. The development of strategies targeted towards poorly educated parents within low-wealth quintiles that may not typically access healthcare could improve vaccination rates. PMID:29432552
An equity dashboard to monitor vaccination coverage.
Arsenault, Catherine; Harper, Sam; Nandi, Arijit; Rodríguez, José M Mendoza; Hansen, Peter M; Johri, Mira
2017-02-01
Equity monitoring is a priority for Gavi, the Vaccine Alliance, and for those implementing The 2030 agenda for sustainable development . For its new phase of operations, Gavi reassessed its approach to monitoring equity in vaccination coverage. To help inform this effort, we made a systematic analysis of inequalities in vaccination coverage across 45 Gavi-supported countries and compared results from different measurement approaches. Based on our findings, we formulated recommendations for Gavi's equity monitoring approach. The approach involved defining the vulnerable populations, choosing appropriate measures to quantify inequalities, and defining equity benchmarks that reflect the ambitions of the sustainable development agenda. In this article, we explain the rationale for the recommendations and for the development of an improved equity monitoring tool. Gavi's previous approach to measuring equity was the difference in vaccination coverage between a country's richest and poorest wealth quintiles. In addition to the wealth index, we recommend monitoring other dimensions of vulnerability (maternal education, place of residence, child sex and the multidimensional poverty index). For dimensions with multiple subgroups, measures of inequality that consider information on all subgroups should be used. We also recommend that both absolute and relative measures of inequality be tracked over time. Finally, we propose that equity benchmarks target complete elimination of inequalities. To facilitate equity monitoring, we recommend the use of a data display tool - the equity dashboard - to support decision-making in the sustainable development period. We highlight its key advantages using data from Côte d'Ivoire and Haiti.
An equity dashboard to monitor vaccination coverage
Harper, Sam; Nandi, Arijit; Rodríguez, José M Mendoza; Hansen, Peter M; Johri, Mira
2017-01-01
Abstract Equity monitoring is a priority for Gavi, the Vaccine Alliance, and for those implementing The 2030 agenda for sustainable development. For its new phase of operations, Gavi reassessed its approach to monitoring equity in vaccination coverage. To help inform this effort, we made a systematic analysis of inequalities in vaccination coverage across 45 Gavi-supported countries and compared results from different measurement approaches. Based on our findings, we formulated recommendations for Gavi’s equity monitoring approach. The approach involved defining the vulnerable populations, choosing appropriate measures to quantify inequalities, and defining equity benchmarks that reflect the ambitions of the sustainable development agenda. In this article, we explain the rationale for the recommendations and for the development of an improved equity monitoring tool. Gavi’s previous approach to measuring equity was the difference in vaccination coverage between a country’s richest and poorest wealth quintiles. In addition to the wealth index, we recommend monitoring other dimensions of vulnerability (maternal education, place of residence, child sex and the multidimensional poverty index). For dimensions with multiple subgroups, measures of inequality that consider information on all subgroups should be used. We also recommend that both absolute and relative measures of inequality be tracked over time. Finally, we propose that equity benchmarks target complete elimination of inequalities. To facilitate equity monitoring, we recommend the use of a data display tool – the equity dashboard – to support decision-making in the sustainable development period. We highlight its key advantages using data from Côte d’Ivoire and Haiti. PMID:28250513
Health care expenditure burdens among adults with diabetes in 2001.
Bernard, Didem M; Banthin, Jessica S; Encinosa, William E
2006-03-01
High out-of-pocket costs can pose a significant burden on patients with chronic conditions such as diabetes and contribute to decreased treatment adherence. We examined financial burdens among adults with diabetes using nationally representative data. estimated how frequently adults with diabetes live in families in which spending on health insurance premiums and health care services exceed a specified percentage of family-level after-tax disposable income. We found that adults with diabetes face greater risks of high burdens compared with adults with any other highly prevalent medical condition. Adults with diabetes have lower incomes and pay a higher share of total expenditures out-of-pocket compared with adults with heart disease, hypertension, and cancer. Among adults with diabetes, women, those who live in poverty, and those with coexisting conditions are more likely to bear high burdens. Among nonelderly adults, those with public coverage and the uninsured have greater risk of high burdens compared with those with private insurance. More than 23% of the uninsured and more than 20% of those with public coverage spend more than half of their disposable income on health care. Among the elderly, those with private nonemployment related insurance have the greatest risk of high burdens followed by those with Medicare only, those with private employment-related coverage, and those enrolled in Medicaid. Prescription medications and diabetic supplies account for 63% to 70% of out-of-pocket expenditures among the nonelderly and 62% to 69% among the elderly. Our study identifies the subpopulations among adults with diabetes who are more likely to have high burdens, so that intervention measures can be targeted to help reduce treatment noncompliance. Our analysis also emphasizes the role of medications and diabetic supplies in contributing to high out-of-pocket burdens.
A catalog of putative adverse outcome pathways (AOPs) that ...
A number of putative AOPs for several distinct MIEs of thyroid disruption have been formulated for amphibian metamorphosis and fish swim bladder inflation. These have been entered into the AOP knowledgebase on the OECD WIKI. The EDSP has been actively advancing high-throughput screening for chemical activity toward estrogen, androgen and thyroid targets. However, it has been recently identified that coverage for thyroid-related targets is lagging behind estrogen and androgen assay coverage. As thyroid-related medium-high throughput assays are actively being developed for inclusion in the ToxCast chemical screening program, a parallel effort is underway to characterize putative adverse outcome pathways (AOPs) specific to these thyroid-related targets. This effort is intended to provide biological and ecological context that will enhance the utility of ToxCast high throughput screening data for hazard identification.
Masanja, Honorati; Schellenberg, Joanna Armstrong; Mshinda, Hassan M; Shekar, Meera; Mugyabuso, Joseph K L; Ndossi, Godwin D; de Savigny, Don
2006-11-01
Efficient delivery strategies for health interventions are essential for high and sustainable coverage. We report impact of a change in programmatic delivery strategy from routine delivery through the Expanded Programme on Immunization (EPI+) approach to twice-yearly mass distribution campaigns on coverage of vitamin A supplementation in Tanzania We investigated disparities in age, sex, socio-economic status, nutritional status and maternal education within vitamin A coverage in children between 1 and 2 years of age from two independent household level child health surveys conducted (1) during a continuous universal targeting scheme based on routine EPI contacts for children aged 9, 15 and 21 months (1999); and (2) three years later after the introduction of twice-yearly vitamin A supplementation campaigns for children aged 6 months to 5 years, a 6-monthly universal targeting scheme (2002). A representative cluster sample of approximately 2,400 rural households was obtained from Rufiji, Morogoro Rural, Kilombero and Ulanga districts. A modular questionnaire about the health of all children under the age of five was administered to consenting heads of households and caretakers of children. Information on the use of child health interventions including vitamin A was asked. Coverage of vitamin A supplementation among 1-2 year old children increased from 13% [95% CI 10-18%] in 1999 to 76% [95%CI 72-81%] in 2002. In 2002 knowledge of two or more child health danger signs was negatively associated with vitamin A supplementation coverage (80% versus 70%) (p = 0.04). Nevertheless, we did not find any disparities in coverage of vitamin A by district, gender, socio-economic status and DPT vaccinations. Change in programmatic delivery of vitamin A supplementation was associated with a major improvement in coverage in Tanzania that was been sustained by repeated campaigns for at least three years. There is a need to monitor the effect of such campaigns on the routine health system and on equity of coverage. Documentation of vitamin A supplementation campaign contacts on routine maternal and child health cards would be a simple step to facilitate this monitoring.
Effectiveness of interventions that apply new media to improve vaccine uptake and vaccine coverage.
Odone, Anna; Ferrari, Antonio; Spagnoli, Francesca; Visciarelli, Sara; Shefer, Abigail; Pasquarella, Cesira; Signorelli, Carlo
2015-01-01
Vaccine-preventable diseases (VPD) are still a major cause of morbidity and mortality worldwide. In high and middle-income settings, immunization coverage is relatively high. However, in many countries coverage rates of routinely recommended vaccines are still below the targets established by international and national advisory committees. Progress in the field of communication technology might provide useful tools to enhance immunization strategies. To systematically collect and summarize the available evidence on the effectiveness of interventions that apply new media to promote vaccination uptake and increase vaccination coverage. We conducted a systematic literature review. Studies published from January 1999 to September 2013 were identified by searching electronic resources (Pubmed, Embase), manual searches of references and expert consultation. Study setting We focused on interventions that targeted recommended vaccinations for children, adolescents and adults and: (1) aimed at increasing community demand for immunizations, or (2) were provider-based interventions. We limited the study setting to countries that are members of the Organisation for Economic Co-operation and Development (OECD). The primary outcome was a measure of vaccination (vaccine uptake or vaccine coverage). Considered secondary outcomes included willingness to receive immunization, attitudes and perceptions toward vaccination, and perceived helpfulness of the intervention. Nineteen studies were included in the systematic review. The majority of the studies were conducted in the US (74%, n = 14); 68% (n = 13) of the studies were experimental, the rest having an observational study design. Eleven (58%) reported results on the primary outcome. Retrieved studies explored the role of: text messaging (n.7, 37%), smartphone applications (n.1, 5%), Youtube videos (n.1, 5%), Facebook (n.1, 5%), targeted websites and portals (n.4, 21%), software for physicians and health professionals (n.4, 21%), and email communication (n.1, 5%). There is some evidence that text messaging, accessing immunization campaign websites, using patient-held web-based portals and computerized reminders increase immunization coverage rates. Insufficient evidence is available on the use of social networks, email communication and smartphone applications. Although there is great potential for improving vaccine uptake and vaccine coverage by implementing programs and interventions that apply new media, scant data are available and further rigorous research - including cost-effectiveness assessments - is needed.
Kiware, Samson S; Corliss, George; Merrill, Stephen; Lwetoijera, Dickson W; Devine, Gregor; Majambere, Silas; Killeen, Gerry F
2015-01-01
Large-cage experiments indicate pyriproxifen (PPF) can be transferred from resting sites to aquatic habitats by Anopheles arabiensis--malaria vector mosquitoes to inhibit emergence of their own offspring. PPF coverage is amplified twice: (1) partial coverage of resting sites with PPF contamination results in far higher contamination coverage of adult mosquitoes because they are mobile and use numerous resting sites per gonotrophic cycle, and (2) even greater contamination coverage of aquatic habitats results from accumulation of PPF from multiple oviposition events. Deterministic mathematical models are described that use only field-measurable input parameters and capture the biological processes that mediate PPF autodissemination. Recent successes in large cages can be rationalized, and the plausibility of success under full field conditions can be evaluated a priori. The model also defines measurable properties of PPF delivery prototypes that may be optimized under controlled experimental conditions to maximize chances of success in full field trials. The most obvious flaw in this model is the endogenous relationship that inevitably occurs between the larval habitat coverage and the measured rate of oviposition into those habitats if the target mosquito species is used to mediate PPF transfer. However, this inconsistency also illustrates the potential advantages of using a different, non-target mosquito species for contamination at selected resting sites that shares the same aquatic habitats as the primary target. For autodissemination interventions to eliminate malaria transmission or vector populations during the dry season window of opportunity will require comprehensive contamination of the most challenging subset of aquatic habitats [Formula: see text] that persist or retain PPF activity (Ux) for only one week [Formula: see text], where Ux = 7 days). To achieve >99% contamination coverage of these habitats will necessitate values for the product of the proportional coverage of the ovipositing mosquito population with PPF contamination (CM) by the ovitrap-detectable rates of oviposition by wild mosquitoes into this subset of habitats [Formula: see text], divided by the titre of contaminated mosquitoes required to render them unproductive [Formula: see text], that approximately approach unity [Formula: see text]. The simple multiplicative relationship between CM and [Formula: see text], and the simple exponential decay effect they have upon uncontaminated aquatic habitats, allows application of this model by theoreticians and field biologists alike.
Effectiveness of interventions that apply new media to improve vaccine uptake and vaccine coverage
Odone, Anna; Ferrari, Antonio; Spagnoli, Francesca; Visciarelli, Sara; Shefer, Abigail; Pasquarella, Cesira; Signorelli, Carlo
2014-01-01
Background Vaccine-preventable diseases (VPD) are still a major cause of morbidity and mortality worldwide. In high and middle-income settings, immunization coverage is relatively high. However, in many countries coverage rates of routinely recommended vaccines are still below the targets established by international and national advisory committees. Progress in the field of communication technology might provide useful tools to enhance immunization strategies. Objective To systematically collect and summarize the available evidence on the effectiveness of interventions that apply new media to promote vaccination uptake and increase vaccination coverage. Design We conducted a systematic literature review. Studies published from January 1999 to September 2013 were identified by searching electronic resources (Pubmed, Embase), manual searches of references and expert consultation. Study setting We focused on interventions that targeted recommended vaccinations for children, adolescents and adults and: (1) aimed at increasing community demand for immunizations, or (2) were provider-based interventions. We limited the study setting to countries that are members of the Organisation for Economic Co-operation and Development (OECD). Main outcome measures The primary outcome was a measure of vaccination (vaccine uptake or vaccine coverage). Considered secondary outcomes included willingness to receive immunization, attitudes and perceptions toward vaccination, and perceived helpfulness of the intervention. Results Nineteen studies were included in the systematic review. The majority of the studies were conducted in the US (74%, n = 14); 68% (n = 13) of the studies were experimental, the rest having an observational study design. Eleven (58%) reported results on the primary outcome. Retrieved studies explored the role of: text messaging (n.7, 37%), smartphone applications (n.1, 5%), Youtube videos (n.1, 5%), Facebook (n.1, 5%), targeted websites and portals (n.4, 21%), software for physicians and health professionals (n.4, 21%), and email communication (n.1, 5%). There is some evidence that text messaging, accessing immunization campaign websites, using patient-held web-based portals and computerized reminders increase immunization coverage rates. Insufficient evidence is available on the use of social networks, email communication and smartphone applications. Conclusion Although there is great potential for improving vaccine uptake and vaccine coverage by implementing programs and interventions that apply new media, scant data are available and further rigorous research - including cost-effectiveness assessments - is needed. PMID:25483518
Barbaro, Bianca; Brotherton, Julia M L
2015-08-01
To compare the use of two alternative population-based denominators in calculating HPV vaccine coverage in Australia by age groups, jurisdiction and remoteness areas. Data from the National HPV Vaccination Program Register (NHVPR) were analysed at Local Government Area (LGA) level, by state/territory and by the Australian Standard Geographical Classification Remoteness Structure. The proportion of females vaccinated was calculated using both the ABS ERP and Medicare enrolments as the denominator. HPV vaccine coverage estimates were slightly higher using Medicare enrolments than using the ABS estimated resident population nationally (70.8% compared with 70.4% for 12 to 17-year-old females, and 33.3% compared with 31.9% for 18 to 26-year-old females, respectively.) The greatest differences in coverage were found in the remote areas of Australia. There is minimal difference between coverage estimates made using the two denominators except in Remote and Very Remote areas where small residential populations make interpretation more difficult. Adoption of Medicare enrolments for the denominator in the ongoing program would make minimal, if any, difference to routine coverage estimates. © 2015 Public Health Association of Australia.
Troeller, Almut; Garny, Sylvia; Pachmann, Sophia; Kantz, Steffi; Gerum, Sabine; Manapov, Farkhad; Ganswindt, Ute; Belka, Claus; Söhn, Matthias
2015-02-22
The use of high accuracy dose calculation algorithms, such as Monte Carlo (MC) and Collapsed Cone (CC) determine dose in inhomogeneous tissue more accurately than pencil beam (PB) algorithms. However, prescription protocols based on clinical experience with PB are often used for treatment plans calculated with CC. This may lead to treatment plans with changes in field size (FS) and changes in dose to organs at risk (OAR), especially for small tumor volumes in lung tissue treated with SABR. We re-evaluated 17 3D-conformal treatment plans for small intrapulmonary lesions with a prescription of 60 Gy in fractions of 7.5 Gy to the 80% isodose. All treatment plans were initially calculated in Oncentra MasterPlan® using a PB algorithm and recalculated with CC (CCre-calc). Furthermore, a CC-based plan with coverage similar to the PB plan (CCcov) and a CC plan with relaxed coverage criteria (CCclin), were created. The plans were analyzed in terms of Dmean, Dmin, Dmax and coverage for GTV, PTV and ITV. Changes in mean lung dose (MLD), V10Gy and V20Gy were evaluated for the lungs. The re-planned CC plans were compared to the original PB plans regarding changes in total monitor units (MU) and average FS. When PB plans were recalculated with CC, the average V60Gy of GTV, ITV and PTV decreased by 13.2%, 19.9% and 41.4%, respectively. Average Dmean decreased by 9% (GTV), 11.6% (ITV) and 14.2% (PTV). Dmin decreased by 18.5% (GTV), 21.3% (ITV) and 17.5% (PTV). Dmax declined by 7.5%. PTV coverage correlated with PTV volume (p < 0.001). MLD, V10Gy, and V20Gy were significantly reduced in the CC plans. Both, CCcov and CCclin had significantly increased MUs and FS compared to PB. Recalculation of PB plans for small lung lesions with CC showed a strong decline in dose and coverage in GTV, ITV and PTV, and declined dose in the lung. Thus, switching from a PB algorithm to CC, while aiming to obtain similar target coverage, can be associated with application of more MU and extension of radiotherapy fields, causing greater OAR exposition.
Fottrell, Edward; Azad, Kishwar; Kuddus, Abdul; Younes, Layla; Shaha, Sanjit; Nahar, Tasmin; Aumon, Bedowra Haq; Hossen, Munir; Beard, James; Hossain, Tanvir; Pulkki-Brannstrom, Anni-Maria; Skordis-Worrall, Jolene; Prost, Audrey; Costello, Anthony; Houweling, Tanja A J
2013-09-01
Community-based interventions can reduce neonatal mortality when health systems are weak. Population coverage of target groups may be an important determinant of their effect on behavior and mortality. A women's group trial at coverage of 1 group per 1414 population in rural Bangladesh showed no effect on neonatal mortality, despite a similar intervention having a significant effect on neonatal and maternal death in comparable settings. To assess the effect of a participatory women's group intervention with higher population coverage on neonatal mortality in Bangladesh. A cluster randomized controlled trial in 9 intervention and 9 control clusters. Rural Bangladesh. Women permanently residing in 18 unions in 3 districts and accounting for 19 301 births during the final 24 months of the intervention. Women's groups at a coverage of 1 per 309 population that proceed through a participatory learning and action cycle in which they prioritize issues that affected maternal and neonatal health and design and implement strategies to address these issues. Neonatal mortality rate. Analysis included 19 301 births during the final 24 months of the intervention. More than one-third of newly pregnant women joined the groups. The neonatal mortality rate was significantly lower in the intervention arm (21.3 neonatal deaths per 1000 live births vs 30.1 per 1000 in control areas), a reduction in neonatal mortality of 38% (risk ratio, 0.62 [95% CI, 0.43-0.89]) when adjusted for socioeconomic factors. The cost-effectiveness was US $220 to $393 per year of life lost averted. Cause-specific mortality rates suggest reduced deaths due to infections and those associated with prematurity/low birth weight. Improvements were seen in hygienic home delivery practices, newborn thermal care, and breastfeeding practices. Women's group community mobilization, delivered at adequate population coverage, is a highly cost-effective approach to improve newborn survival and health behavior indicators in rural Bangladesh. isrctn.org Identifier: ISRCTN01805825.
The challenges of achieving high training coverage for IMCI: case studies from Kenya and Tanzania
Mushi, Hildegalda P; Mullei, Kethi; Macha, Janet; Wafula, Frank; Borghi, Josephine; Goodman, Catherine; Gilson, Lucy
2011-01-01
Health worker training is a key component of the integrated management of childhood illness (IMCI). However, training coverage remains low in many countries. We conducted in-depth case studies in two East African countries to examine the factors underlying low training coverage 10 years after IMCI had been adopted as policy. A document review and in-depth semi-structured interviews with stakeholders at facility, district, regional/provincial and national levels in two districts in Kenya (Homa Bay and Malindi) and Tanzania (Bunda and Tarime) were carried out in 2007–08. Bunda and Malindi achieved higher levels of training coverage (44% and 25%) compared with Tarime and Homa Bay (5% and 13%). Key factors allowing the first two districts to perform better were: strong district leadership and personal commitment to IMCI, which facilitated access to external funding and encouraged local-level policy adaptation; sensitization and training of district health managers; and lower staff turnover. However, IMCI training coverage remained well below target levels across all sites. The main barrier to expanding coverage was the cost of training due to its duration, the number of facilitators and its residential nature. Mechanisms for financing IMCI also restricted district capacity to raise funds. In Tanzania, districts could not spend more than 10% of their budgets on training. In Kenya, limited financial decentralization meant that district managers had to rely on donors for financial support. Critically, the low priority given to IMCI at national and international levels also limited the expansion of training. Levels of domestic and donor support for IMCI have diminished over time in favour of vertical programmes, partly due to the difficulty in monitoring and measuring the impact of an integrated intervention like IMCI. Alternative, lower cost methods of IMCI training need to be promoted, and greater advocacy for IMCI is needed both nationally and internationally. PMID:21047808
van der Laan, Hans Paul; Dolsma, Wil V; Maduro, John H; Korevaar, Erik W; Hollander, Miranda; Langendijk, Johannes A
2007-07-15
To compare the target coverage and normal tissue dose with the simultaneously integrated boost (SIB) and the sequential boost technique in breast cancer, and to evaluate the incidence of acute skin toxicity in patients treated with the SIB technique. Thirty patients with early-stage left-sided breast cancer underwent breast-conserving radiotherapy using the SIB technique. The breast and boost planning target volumes (PTVs) were treated simultaneously (i.e., for each fraction, the breast and boost PTVs received 1.81 Gy and 2.3 Gy, respectively). Three-dimensional conformal beams with wedges were shaped and weighted using forward planning. Dose-volume histograms of the PTVs and organs at risk with the SIB technique, 28 x (1.81 + 0.49 Gy), were compared with those for the sequential boost technique, 25 x 2 Gy + 8 x 2 Gy. Acute skin toxicity was evaluated for 90 patients treated with the SIB technique according to Common Terminology Criteria for Adverse Events, version 3.0. PTV coverage was adequate with both techniques. With SIB, more efficiently shaped boost beams resulted in smaller irradiated volumes. The mean volume receiving > or =107% of the breast dose was reduced by 20%, the mean volume outside the boost PTV receiving > or =95% of the boost dose was reduced by 54%, and the mean heart and lung dose were reduced by 10%. Of the evaluated patients, 32.2% had Grade 2 or worse toxicity. The SIB technique is proposed for standard use in breast-conserving radiotherapy because of its dose-limiting capabilities, easy implementation, reduced number of treatment fractions, and relatively low incidence of acute skin toxicity.
Michiels, Steven; Poels, Kenneth; Crijns, Wouter; Delombaerde, Laurence; De Roover, Robin; Vanstraelen, Bianca; Haustermans, Karin; Nuyts, Sandra; Depuydt, Tom
2018-05-05
Linac improvements in gantry speed, leaf speed and dose rate may increase the time-efficiency of volumetric modulated arc therapy (VMAT) delivery. The plan quality achievable with faster VMAT however remains to be investigated. In this study, a fast-rotating O-ring linac with fast-moving leaves is compared with a C-arm linac in terms of plan quality and delivery time for VMAT of head-and-neck cancer (HNC). For 30 patients with HNC, treatment planning was performed using dual-arc (HA2) and triple-arc (HA3) VMAT on a Halcyon fast-rotating O-ring linac and using dual-arc VMAT on a TrueBeam C-arm linac (TB2). Target coverage metrics and complication probabilities were compared. Plan delivery was verified using 3%/3 mm gamma-index analysis of helical diode array measurements. Volumetric image acquisition and plan delivery times were compared. All studied VMAT-techniques fulfilled the target coverage objectives. D 2% to the boost volume was higher for HA2 (median 103.7%, 1st-3rd quartile [103.5%;104.0%]) and HA3 (103.2% [103.0%;103.7%)] than for TB2 (102.6% [102.3%;103.0%)], resulting in an increased boost target dose heterogeneity for HA2 and HA3. Complication probabilities were comparable between HA2 and TB2, while HA3 showed a xerostomia probability reduction (0.8% [0.2%;1.8%]) and dysphagia probability reduction (1.0% [0.2%;1.8%]) compared with TB2. Gamma-index agreement scores were never below 93.0% for HA2, HA3 and TB2. Volumetric imaging and plan delivery time was shorter for HA2 (1 m 24 s ± 1 s) and HA3 (1 m 54 s ± 1 s) than for TB2 (2 m 47 s ± 1 s). For VMAT of HNC, the fast-rotating O-ring linac at least maintains the plan quality of two arcs on a C-arm linac while reducing the image acquisition and plan delivery time. Copyright © 2018 Elsevier B.V. All rights reserved.
Everts-van der Wind, Annelie; Kata, Srinivas R.; Band, Mark R.; Rebeiz, Mark; Larkin, Denis M.; Everts, Robin E.; Green, Cheryl A.; Liu, Lei; Natarajan, Shreedhar; Goldammer, Tom; Lee, Jun Heon; McKay, Stephanie; Womack, James E.; Lewin, Harris A.
2004-01-01
A second-generation 5000 rad radiation hybrid (RH) map of the cattle genome was constructed primarily using cattle ESTs that were targeted to gaps in the existing cattle–human comparative map, as well as to sparsely populated map intervals. A total of 870 targeted markers were added, bringing the number of markers mapped on the RH5000 panel to 1913. Of these, 1463 have significant BLASTN hits (E < e–5) against the human genome sequence. A cattle–human comparative map was created using human genome sequence coordinates of the paired orthologs. One-hundred and ninety-five conserved segments (defined by two or more genes) were identified between the cattle and human genomes, of which 31 are newly discovered and 34 were extended singletons on the first-generation map. The new map represents an improvement of 20% genome-wide comparative coverage compared with the first-generation map. Analysis of gene content within human genome regions where there are gaps in the comparative map revealed gaps with both significantly greater and significantly lower gene content. The new, more detailed cattle–human comparative map provides an improved resource for the analysis of mammalian chromosome evolution, the identification of candidate genes for economically important traits, and for proper alignment of sequence contigs on cattle chromosomes. PMID:15231756
Moseley, Douglas; Kassam, Zahra; Kim, Sun Mo; Cho, Charles
2013-01-01
Recently, volumetric‐modulated arc therapy (VMAT) has demonstrated the ability to deliver radiation dose precisely and accurately with a shorter delivery time compared to conventional intensity‐modulated fixed‐field treatment (IMRT). We applied the hypothesis of VMAT technique for the treatment of thoracic esophageal carcinoma to determine superior or equivalent conformal dose coverage for a large thoracic esophageal planning target volume (PTV) with superior or equivalent sparing of organs‐at‐risk (OARs) doses, and reduce delivery time and monitor units (MUs), in comparison with conventional fixed‐field IMRT plans. We also analyzed and compared some other important metrics of treatment planning and treatment delivery for both IMRT and VMAT techniques. These metrics include: 1) the integral dose and the volume receiving intermediate dose levels between IMRT and VMATI plans; 2) the use of 4D CT to determine the internal motion margin; and 3) evaluating the dosimetry of every plan through patient‐specific QA. These factors may impact the overall treatment plan quality and outcomes from the individual planning technique used. In this study, we also examined the significance of using two arcs vs. a single‐arc VMAT technique for PTV coverage, OARs doses, monitor units and delivery time. Thirteen patients, stage T2‐T3 N0‐N1 (TNM AJCC 7th edn.), PTV volume median 395 cc (range 281–601 cc), median age 69 years (range 53 to 85), were treated from July 2010 to June 2011 with a four‐field (n=4) or five‐field (n=9) step‐and‐shoot IMRT technique using a 6 MV beam to a prescribed dose of 50 Gy in 20 to 25 F. These patients were retrospectively replanned using single arc (VMATI, 91 control points) and two arcs (VMATII, 182 control points). All treatment plans of the 13 study cases were evaluated using various dose‐volume metrics. These included PTV D99, PTV D95, PTV V9547.5Gy(95%), PTV mean dose, Dmax, PTV dose conformity (Van't Riet conformation number (CN)), mean lung dose, lung V20 and V5, liver V30, and Dmax to the spinal canal prv3mm. Also examined were the total plan monitor units (MUs) and the beam delivery time. Equivalent target coverage was observed with both VMAT single and two‐arc plans. The comparison of VMATI with fixed‐field IMRT demonstrated equivalent target coverage; statistically no significant difference were found in PTV D99 (p=0.47), PTV mean (p=0.12), PTV D95 and PTV V9547.5Gy (95%) (p=0.38). However, Dmax in VMATI plans was significantly lower compared to IMRT (p=0.02). The Van't Riet dose conformation number (CN) was also statistically in favor of VMATI plans (p=0.04). VMATI achieved lower lung V20 (p=0.05), whereas lung V5 (p=0.35) and mean lung dose (p=0.62) were not significantly different. The other OARs, including spinal canal, liver, heart, and kidneys showed no statistically significant differences between the two techniques. Treatment time delivery for VMATI plans was reduced by up to 55% (p=5.8E−10) and MUs reduced by up to 16% (p=0.001). Integral dose was not statistically different between the two planning techniques (p=0.99). There were no statistically significant differences found in dose distribution of the two VMAT techniques (VMATI vs. VMATII) Dose statistics for both VMAT techniques were: PTV D99 (p=0.76), PTV D95 (p=0.95), mean PTV dose (p=0.78), conformation number (CN) (p=0.26), and MUs (p=0.1). However, the treatment delivery time for VMATII increased significantly by two‐fold (p=3.0E−11) compared to VMATI. VMAT‐based treatment planning is safe and deliverable for patients with thoracic esophageal cancer with similar planning goals, when compared to standard IMRT. The key benefit for VMATI was the reduction in treatment delivery time and MUs, and improvement in dose conformality. In our study, we found no significant difference in VMATII over single‐arc VMATI for PTV coverage or OARs doses. However, we observed significant increase in delivery time for VMATII compared to VMATI. PACS number: 87.53.Kn, 87.55.‐x PMID:23652258
Dosimetric effect on pediatric conformal treatment plans using dynamic jaw with Tomotherapy HDA
DOE Office of Scientific and Technical Information (OSTI.GOV)
Han, Eun Young, E-mail: eyhan@uams.edu; Kim, Dong-Wook; Zhang, Xin
It is important to minimize the radiation dose delivered to healthy tissues in pediatric cancer treatment because of the risk of secondary malignancies. Tomotherapy HDA provides a dynamic jaw (DJ) delivery mode that creates a sharper penumbra at the craniocaudal ends of a target in addition to a fixed jaw (FJ) delivery mode. The purpose of this study was to evaluate its dosimetric effect on the pediatric cancer cases. We included 6 pediatric cases in this study. The dose profiles and plan statistics—target dose conformity, uniformity, organ-at-risk (OAR) mean dose, beam-on time, and integral dose—were compared for each case. Consequently,more » the target dose coverage and uniformity were similar for different jaw settings. The OAR dose sparing depended on its relative location to the target and disease sites. For example, in the head and neck cancer cases, the brain stem dose using DJ 2.5 was reduced by more than two-fold (2.4 Gy vs. 6.3 Gy) than that obtained with FJ 2.5. The integral dose with DJ 2.5 decreased by more than 9% compared with that with FJ 2.5. Thus, using dynamic jaw in pediatric cases could be critical to reduce a probability of a secondary malignancy.« less
Arbyn, Marc; Fabri, Valérie; Temmerman, Marleen; Simoens, Cindy
2014-01-01
Objective To assess the coverage for cervical cancer screening as well as the use of cervical cytology, colposcopy and other diagnostic and therapeutic interventions on the uterine cervix in Belgium, using individual health insurance data. Methods The Intermutualistic Agency compiled a database containing 14 million records from reimbursement claims for Pap smears, colposcopies, cervical biopsies and surgery, performed between 2002 and 2006. Cervical cancer screening coverage was defined as the proportion of women aged 25–64 that had a Pap smear within the last 3 years. Results Cervical cancer screening coverage was 61% at national level, for the target population of women between 25 and 64 years old, in the period 2004–2006. Differences between the 3 regions were small, but varied more substantially between provinces. Coverage was 70% for 25–34 year old women, 67% for those aged 35–39 years, and decreased to 44% in the age group of 60–64 years. The median screening interval was 13 months. The screening coverage varied substantially by social category: 40% and 64%, in women categorised as beneficiary or not-beneficiary of increased reimbursement from social insurance, respectively. In the 3-year period 2004–2006, 3.2 million screen tests were done in the target group consisting of 2.8 million women. However, only 1.7 million women got one or more smears and 1.1 million women had no smears, corresponding to an average of 1.88 smears per woman in three years of time. Colposcopy was excessively used (number of Pap smears over colposcopies = 3.2). The proportion of women with a history of conisation or hysterectomy, before the age of 65, was 7% and 19%, respectively. Conclusion The screening coverage increased slightly from 59% in 2000 to 61% in 2006. The screening intensity remained at a high level, and the number of cytological examinations was theoretically sufficient to cover more than the whole target population. PMID:24690620
Ward, Zoe; Platt, Lucy; Sweeney, Sedona; Hope, Vivian D; Maher, Lisa; Hutchinson, Sharon; Palmateer, Norah; Smith, Josie; Craine, Noel; Taylor, Avril; Martin, Natasha; Ayres, Rachel; Dillon, John; Hickman, Matthew; Vickerman, Peter
2018-05-17
To estimate the impact of existing high-coverage needle and syringe provision (HCNSP, defined as obtaining more than one sterile needle and syringe per injection reported) and opioid substitution therapy (OST) on hepatitis C virus (HCV) transmission among people who inject drugs (PWID) in three UK settings and to determine required scale-up of interventions, including HCV treatment, needed to reach the World Health Organization (WHO) target of reducing HCV incidence by 90% by 2030. HCV transmission modelling using UK empirical estimates for effect of OST and/or HCNSP on individual risk of HCV acquisition. Three UK cities with varying chronic HCV prevalence (Bristol 45%, Dundee 26%, Walsall 19%), OST (72-81%) and HCNSP coverage (28-56%). Relative change in new HCV infections throughout 2016-30 if current interventions were stopped. Scale-up of HCNSP, OST and HCV treatment required to achieve the WHO elimination target. Removing HCNSP or OST would increase the number of new HCV infections throughout 2016 to 2030 by 23-64 and 92-483%, respectively. Conversely, scaling-up these interventions to 80% coverage could achieve a 29 or 49% reduction in Bristol and Walsall, respectively, whereas Dundee may achieve a 90% decrease in incidence with current levels of intervention because of existing high levels of HCV treatment (47-58 treatments per 1000 PWID). If OST and HCNSP are scaled-up, Walsall and Bristol can achieve the same impact by treating 14 or 40 per 1000 PWID annually, respectively (currently two and nine treatments per 1000 PWID), while 18 and 43 treatments per 1000 PWID would be required if OST and HCNSP are not scaled-up. Current opioid substitution therapy and high-coverage needle and syringe provision coverage is averting substantial hepatitis C transmission in the United Kingdom. Maintaining this coverage while getting current drug injectors onto treatment can reduce incidence by 90% by 2030. © 2018 The Authors. Addiction published by John Wiley & Sons Ltd on behalf of Society for the Study of Addiction.
Using lot quality assurance sampling to improve immunization coverage in Bangladesh.
Tawfik, Y.; Hoque, S.; Siddiqi, M.
2001-01-01
OBJECTIVE: To determine areas of low vaccination coverage in five cities in Bangladesh (Chittagong, Dhaka, Khulna, Rajshahi, and Syedpur). METHODS: Six studies using lot quality assurance sampling were conducted between 1995 and 1997 by Basic Support for Institutionalizing Child Survival and the Bangladesh National Expanded Programme on Immunization. FINDINGS: BCG vaccination coverage was acceptable in all lots studied; however, the proportion of lots rejected because coverage of measles vaccination was low ranged from 0% of lots in Syedpur to 12% in Chittagong and 20% in Dhaka's zones 7 and 8. The proportion of lots rejected because an inadequate number of children in the sample had been fully vaccinated varied from 11% in Syedpur to 30% in Dhaka. Additionally, analysis of aggregated, weighted immunization coverage showed that there was a high BCG vaccination coverage (the first administered vaccine) and a low measles vaccination coverage (the last administered vaccine) indicating a high drop-out rate, ranging from 14% in Syedpur to 36% in Dhaka's zone 8. CONCLUSION: In Bangladesh, where resources are limited, results from surveys using lot quality assurance sampling enabled managers of the National Expanded Programme on Immunization to identify areas with poor vaccination coverage. Those areas were targeted to receive focused interventions to improve coverage. Since this sampling method requires only a small sample size and was easy for staff to use, it is feasible for routine monitoring of vaccination coverage. PMID:11436470
22 CFR Appendix I to Part 211 - Operational Plan
Code of Federal Regulations, 2010 CFR
2010-04-01
.... If there are several objectives, indicate priorities. c. Describe the target population by program... coverage and the percent of total target population reached. d. Describe the intervention including: (1... World Food Program) emergency request normally requires more Mission involvement in program design and...
NASA Astrophysics Data System (ADS)
Anderson, Monica; David, Phillip
2007-04-01
Implementation of an intelligent, automated target acquisition and tracking systems alleviates the need for operators to monitor video continuously. This system could identify situations that fatigued operators could easily miss. If an automated acquisition and tracking system plans motions to maximize a coverage metric, how does the performance of that system change when the user intervenes and manually moves the camera? How can the operator give input to the system about what is important and understand how that relates to the overall task balance between surveillance and coverage? In this paper, we address these issues by introducing a new formulation of the average linear uncovered length (ALUL) metric, specially designed for use in surveilling urban environments. This metric coordinates the often competing goals of acquiring new targets and tracking existing targets. In addition, it provides current system performance feedback to system users in terms of the system's theoretical maximum and minimum performance. We show the successful integration of the algorithm via simulation.
Hafiz, Israt; Berhan, Meklit; Keller, Angela; Haq, Rouseli; Chesnaye, Nicholas; Koporc, Kim; Rahman, Mujibur; Rahman, Shamsur; Mathieu, Els
2015-01-01
Bangladesh's national deworming program targets school-age children (SAC) through bi-annual school-based distributions of mebendazole. Qualitative and quantitative methods were applied to identify challenges related to treatment monitoring within the Munshiganj and Lakshmipur Districts of Bangladesh. Key stakeholder interviews identified several obstacles for successful treatment monitoring within these districts; ambiguity in defining the target population, variances in the methods used for compiling and reporting treatment data, and a general lack of financial and human resources. A treatment coverage cluster survey revealed that bi-annual primary school-based distributions proved to be an effective strategy in reaching school-attending SAC, with rates between 63.0% and 73.3%. However, the WHO target of regular treatment of at least 75% of SAC has yet to be reached. Particularly low coverage was seen amongst non-school attending children (11.4-14.3%), most likely due to the lack of national policy to effectively target this vulnerable group. Survey findings on water and sanitation coverage were impressive with the majority of households and schools having access to latrines (98.6-99.3%) and safe drinking water (98.2-100%). The challenge now for the Bangladesh control program is to achieve the WHO target of regular treatment of at least 75% of SAC at risk, irrespective of school-enrollment status. Copyright © 2013 The Authors. Published by Elsevier B.V. All rights reserved.
Kunst, H; Burman, M; Arnesen, T M; Fiebig, L; Hergens, M-P; Kalkouni, O; Klinkenberg, E; Orcau, À; Soini, H; Sotgiu, G; Zenner, D; de Vries, G
2017-08-01
Migration patterns into and within Europe have changed over the last decade. In 2015, European Union (EU) countries received over 1.2 million asylum requests, more than double the number registered in the previous year. This review compares the published literature on policies for tuberculosis (TB) and latent tuberculous infection (LTBI) screening in EU and European Free Trade Association (EFTA) countries with the existing TB/LTBI screening programmes for migrants in 11 EU/EFTA countries based on a survey of policy and surveillance systems. In addition, we provide a systematic review of the literature on the yield of screening migrants for active TB and LTBI in Europe. Published studies provide limited information about screening coverage and the yield of screening evaluations in EU/EFTA countries. Furthermore, countries use different screening strategies and settings, and different definitions for coverage and yield of screening for active TB and LTBI. We recommend harmonising case definitions, reporting standards and policies for TB/LTBI screening. To achieve TB elimination targets, a European platform for multi-country data collection and analysis, sharing of countries' policies and practices, and harmonisation of migrant screening strategies is needed.
Brotherton, Julia M L; Bloem, Paul N
2018-02-01
Persistent oncogenic human papillomavirus (HPV) is the cause of cervical cancer, as well as cancers of the anus, penis, vulva, vagina and oropharynx. There is good evidence that prophylactic HPV vaccines are immunogenic and effective against targeted-type HPV infections and type-specific genital lesions, including high-grade cervical intraepithelial neoplasia (CIN), when administered prior to HPV infection. There is good evidence that HPV vaccines are safe in population usage, with the most frequent adverse event being injection-site reactions. There is evidence to support some cross-protection against non-targeted types occurring following the administration of HPV vaccines. There is limited evidence suggesting that HPV vaccines may be beneficial in preventing future disease in women treated for high-grade CIN. This chapter focuses on the accumulated evidence regarding the global use of the three licensed HPV vaccines including safety, immunogenicity, duration of protection, effectiveness, coverage to date and barriers to higher coverage. Copyright © 2018 Elsevier Ltd. All rights reserved.
Zieminski, Stephen; Khandekar, Melin; Wang, Yi
2018-03-01
This study compared the dosimetric performance of (a) volumetric modulated arc therapy (VMAT) with standard optimization (STD) and (b) multi-criteria optimization (MCO) to (c) intensity modulated radiation therapy (IMRT) with MCO for hippocampal avoidance whole brain radiation therapy (HA-WBRT) in RayStation treatment planning system (TPS). Ten HA-WBRT patients previously treated with MCO-IMRT or MCO-VMAT on an Elekta Infinity accelerator with Agility multileaf collimators (5-mm leaves) were re-planned for the other two modalities. All patients received 30 Gy in 15 fractions to the planning target volume (PTV), namely, PTV30 expanded with a 2-mm margin from the whole brain excluding hippocampus with margin. The patients all had metastatic lesions (up to 12) of variable sizes and proximity to the hippocampus, treated with an additional 7.5 Gy from a simultaneous integrated boost (SIB) to PTV37.5. The IMRT plans used eight to eleven non-coplanar fields, whereas the VMAT plans used two coplanar full arcs and a vertex half arc. The averaged target coverage, dose to organs-at-risk (OARs) and monitor unit provided by the three modalities were compared, and a Wilcoxon signed-rank test was performed. MCO-VMAT provided statistically significant reduction of D100 of hippocampus compared to STD-VMAT, and Dmax of cochleas compared to MCO-IMRT. With statistical significance, MCO-VMAT improved V30 of PTV30 by 14.2% and 4.8%, respectively, compared to MCO-IMRT and STD-VMAT. It also raised D95 of PTV37.5 by 0.4 Gy compared to both MCO-IMRT and STD-VMAT. Improved plan quality parameters such as a decrease in overall plan Dmax and total monitor units (MU) were also observed for MCO-VMAT. MCO-VMAT is found to be the optimal modality for HA-WBRT in terms of PTV coverage, OAR sparing and delivery efficiency, compared to MCO-IMRT or STD-VMAT. © 2018 The Authors. Journal of Applied Clinical Medical Physics published by Wiley Periodicals, Inc. on behalf of American Association of Physicists in Medicine.
Braun, Robert T; Hanoch, Yaniv; Barnes, Andrew J
2017-11-15
Under the Affordable Care Act (ACA), millions of Americans have been enrolling in the health insurance marketplaces. Nearly 20% of them are tobacco users. As part of the ACA, tobacco users may face up to 50% higher premiums that are not eligible for tax credits. Tobacco users, along with the uninsured and racial/ethnic minorities targeted by ACA coverage expansions, are among those most likely to suffer from low health literacy - a key ingredient in the ability to understand, compare, choose, and use coverage, referred to as health insurance literacy. Whether tobacco users choose enough coverage in the marketplaces given their expected health care needs and are able to access health care services effectively is fundamentally related to understanding health insurance. However, no studies to date have examined this important relationship. Data were collected from 631 lower-income, minority, rural residents of Virginia. Health insurance literacy was assessed by asking four factual questions about the coverage options presented to them. Adjusted associations between tobacco use and health insurance literacy were tested using multivariate linear regression, controlling for numeracy, risk-taking, discount rates, health status, experiences with the health care system, and demographics. Nearly one third (31%) of participants were current tobacco users, 80% were African American and 27% were uninsured. Average health insurance literacy across all participants was 2.0 (SD 1.1) out of a total possible score of 4. Current tobacco users had significantly lower HIL compared to non-users (-0.22, p < 0.05) after adjustment. Participants who were less educated, African American, and less numerate reported more difficulty understanding health insurance (p < 0.05 each.) CONCLUSIONS: Tobacco users face higher premiums for health coverage than non-users in the individual insurance marketplace. Our results suggest they may be less equipped to shop for plans that provide them with adequate out-of-pocket risk protection, thus placing greater financial burdens on them and potentially limiting access to tobacco cessation and treatment programs and other needed health services.
High-dose naltrexone therapy for cocaine-alcohol dependence.
Schmitz, Joy M; Lindsay, Jan A; Green, Charles E; Herin, David V; Stotts, Angela L; Moeller, F Gerard
2009-01-01
This randomized, double-blind, placebo-controlled study compared the effects of high-dose (100 mg/d) naltrexone versus placebo in a sample of 87 randomized subjects with both cocaine and alcohol dependence. Medication conditions were crossed with two behavioral therapy platforms that examined whether adding contingency management (CM) that targeted cocaine abstinence would enhance naltrexone effects compared to cognitive behavioral therapy (CBT) without CM. Primary outcome measures for cocaine (urine screens) and alcohol use (timeline followback) were collected thrice-weekly during 12 weeks of treatment. Retention in treatment and medication compliance rates were low. Rates of cocaine use and drinks per day did not differ between treatment groups; however naltrexone did reduce frequency of heavy drinking days, as did CBT without CM. Notably, adding CM to CBT did not enhance treatment outcomes. These weak findings suggest that pharmacological and behavioral interventions that have shown efficacy in the treatment of a single drug dependence disorder may not provide the coverage needed when targeting dual drug dependence.
Pinchoff, Jessie; Larsen, David A; Renn, Silvia; Pollard, Derek; Fornadel, Christen; Maire, Mark; Sikaala, Chadwick; Sinyangwe, Chomba; Winters, Benjamin; Bridges, Daniel J; Winters, Anna M
2016-01-06
In Zambia and other sub-Saharan African countries affected by ongoing malaria transmission, indoor residual spraying (IRS) for malaria prevention has typically been implemented over large areas, e.g., district-wide, and targeted to peri-urban areas. However, there is a recent shift in some countries, including Zambia, towards the adoption of a more strategic and targeted IRS approach, in coordination with increased emphasis on universal coverage of long-lasting insecticidal nets (LLINs) and effective insecticide resistance management. A true targeted approach would deliver IRS to sub-district areas identified as high-risk, with the goal of maximizing the prevention of malaria cases and deaths. Together with the Government of the Republic of Zambia, a new methodology was developed applying geographic information systems and satellite imagery to support a targeted IRS campaign during the 2014 spray season using health management information system data. This case study focuses on the developed methodology while also highlighting the significant research gaps which must be filled to guide countries on the most effective strategy for IRS targeting in the context of universal LLIN coverage and evolving insecticide resistance.
Campos, Andre N.; Souza, Efren L.; Nakamura, Fabiola G.; Nakamura, Eduardo F.; Rodrigues, Joel J. P. C.
2012-01-01
Target tracking is an important application of wireless sensor networks. The networks' ability to locate and track an object is directed linked to the nodes' ability to locate themselves. Consequently, localization systems are essential for target tracking applications. In addition, sensor networks are often deployed in remote or hostile environments. Therefore, density control algorithms are used to increase network lifetime while maintaining its sensing capabilities. In this work, we analyze the impact of localization algorithms (RPE and DPE) and density control algorithms (GAF, A3 and OGDC) on target tracking applications. We adapt the density control algorithms to address the k-coverage problem. In addition, we analyze the impact of network density, residual integration with density control, and k-coverage on both target tracking accuracy and network lifetime. Our results show that DPE is a better choice for target tracking applications than RPE. Moreover, among the evaluated density control algorithms, OGDC is the best option among the three. Although the choice of the density control algorithm has little impact on the tracking precision, OGDC outperforms GAF and A3 in terms of tracking time. PMID:22969329
Lakew, Yihunie; Bekele, Alemayhu; Biadgilign, Sibhatu
2015-07-30
Immunization remains one of the most important public health interventions to reduce child morbidity and mortality. The 2011 national demographic and health survey (DHS) indicated low full immunization coverage among children aged 12-23 months in Ethiopia. Factors contributing to the low coverage of immunization have been poorly understood. The aim of this study was to identify factors associated with full immunization coverage among children aged 12-23 months in Ethiopia. This study used the 2011 Ethiopian demographic and health survey data. The survey was cross sectional by design and used a multistage cluster sampling procedure. A total of 1,927 mothers with children of 12-23 months of age were extracted from the children's dataset. Mothers' self-reported data and observations of vaccination cards were used to determine vaccine coverage. An adjusted odds ratio (AOR) with 95% confidence intervals (CI) was used to outline the independent predictors. The prevalence of fully immunized children was 24.3%. Specific vaccination coverage for three doses of DPT, three doses of polio, measles and BCG were 36.5%, 44.3%, 55.7% and 66.3%, respectively. The multivariable analysis showed that sources of information from vaccination card [AOR 95% CI; 7.7 (5.95-10.06)], received postnatal check-up within two months after birth [AOR 95% CI; 1.8 (1.28-2.56)], women's awareness of community conversation program [AOR 95% CI; 1.9 (1.44-2.49)] and women in the rich wealth index [AOR 95% CI; 1.4 (1.06-1.94)] were the predictors of full immunization coverage. Women from Afar [AOR 95% CI; 0.07 (0.01-0.68)], Amhara [AOR 95% CI; 0.33 (0.13-0.81)], Oromiya [AOR 95% CI; 0.15 (0.06-0.37)], Somali [AOR 95% CI; 0.15 (0.04-0.55)] and Southern Nation and Nationalities People administrative regions [AOR 95% CI; 0.35 (0.14-0.87)] were less likely to fully vaccinate their children. The overall full immunization coverage in Ethiopia was considerably low as compared to the national target set (66%). Health service use and access to information on maternal and child health were found to predict full immunization coverage. Appropriate strategies should be devised to enhance health information and accessibility for full immunization coverage by addressing the variations among regions.
Yang, Rendong; Nelson, Andrew C; Henzler, Christine; Thyagarajan, Bharat; Silverstein, Kevin A T
2015-12-07
Comprehensive identification of insertions/deletions (indels) across the full size spectrum from second generation sequencing is challenging due to the relatively short read length inherent in the technology. Different indel calling methods exist but are limited in detection to specific sizes with varying accuracy and resolution. We present ScanIndel, an integrated framework for detecting indels with multiple heuristics including gapped alignment, split reads and de novo assembly. Using simulation data, we demonstrate ScanIndel's superior sensitivity and specificity relative to several state-of-the-art indel callers across various coverage levels and indel sizes. ScanIndel yields higher predictive accuracy with lower computational cost compared with existing tools for both targeted resequencing data from tumor specimens and high coverage whole-genome sequencing data from the human NIST standard NA12878. Thus, we anticipate ScanIndel will improve indel analysis in both clinical and research settings. ScanIndel is implemented in Python, and is freely available for academic use at https://github.com/cauyrd/ScanIndel.
Zhang, Zhi-lun; Zhu, Xiang-jun; Ding, Ya-xing; Xie, Xiao-hua; Gao, Zhi-gang; Li, Yong-cheng; Zhang, Ying; Xia, Wei-dong; Liu, Yong
2007-10-01
To evaluate the effects of prevention and control strategies on hepatitis A. Surveillance data on hepatitis A from 1990 to 2006 in Tianjin was analyzed, and the coverage rate of hepatitis A vaccine among targeted population was estimated, to compare the anti-HAV IgG level of children younger than 15 years old in 1999 and in 2005. Results showed that a) the morbidity of hepatitis A decreased from 25.26/10(5) in 1990 to 0.82/10(5) in 2006; b) the ratio of hepatitis A in viral hepatitis decreased from 30.43% in 1990 to 1.05% in 2006; c) the estimated coverage rate was 72.7%; d) the positive rate of anti-HAV among children younger than 15 years old in 2005 was distinctly higher than that in 1999. Positive results showed that it was successful to use hepatitis A vaccine as the strategy to prevent and control hepatitis A in the past five years in Tianjin.
Inoue, Tatsuya; Widder, Joachim; van Dijk, Lisanne V; Takegawa, Hideki; Koizumi, Masahiko; Takashina, Masaaki; Usui, Keisuke; Kurokawa, Chie; Sugimoto, Satoru; Saito, Anneyuko I; Sasai, Keisuke; Van't Veld, Aart A; Langendijk, Johannes A; Korevaar, Erik W
2016-11-01
To investigate the impact of setup and range uncertainties, breathing motion, and interplay effects using scanning pencil beams in robustly optimized intensity modulated proton therapy (IMPT) for stage III non-small cell lung cancer (NSCLC). Three-field IMPT plans were created using a minimax robust optimization technique for 10 NSCLC patients. The plans accounted for 5- or 7-mm setup errors with ±3% range uncertainties. The robustness of the IMPT nominal plans was evaluated considering (1) isotropic 5-mm setup errors with ±3% range uncertainties; (2) breathing motion; (3) interplay effects; and (4) a combination of items 1 and 2. The plans were calculated using 4-dimensional and average intensity projection computed tomography images. The target coverage (TC, volume receiving 95% of prescribed dose) and homogeneity index (D2 - D98, where D2 and D98 are the least doses received by 2% and 98% of the volume) for the internal clinical target volume, and dose indexes for lung, esophagus, heart and spinal cord were compared with that of clinical volumetric modulated arc therapy plans. The TC and homogeneity index for all plans were within clinical limits when considering the breathing motion and interplay effects independently. The setup and range uncertainties had a larger effect when considering their combined effect. The TC decreased to <98% (clinical threshold) in 3 of 10 patients for robust 5-mm evaluations. However, the TC remained >98% for robust 7-mm evaluations for all patients. The organ at risk dose parameters did not significantly vary between the respective robust 5-mm and robust 7-mm evaluations for the 4 error types. Compared with the volumetric modulated arc therapy plans, the IMPT plans showed better target homogeneity and mean lung and heart dose parameters reduced by about 40% and 60%, respectively. In robustly optimized IMPT for stage III NSCLC, the setup and range uncertainties, breathing motion, and interplay effects have limited impact on target coverage, dose homogeneity, and organ-at-risk dose parameters. Copyright © 2016 Elsevier Inc. All rights reserved.
Sloth Møller, Ditte; Knap, Marianne Marquard; Nyeng, Tine Bisballe; Khalil, Azza Ahmed; Holt, Marianne Ingerslev; Kandi, Maria; Hoffmann, Lone
2017-11-01
Minimizing the planning target volume (PTV) while ensuring sufficient target coverage during the entire respiratory cycle is essential for free-breathing radiotherapy of lung cancer. Different methods are used to incorporate the respiratory motion into the PTV. Fifteen patients were analyzed. Respiration can be included in the target delineation process creating a respiratory GTV, denoted iGTV. Alternatively, the respiratory amplitude (A) can be measured based on the 4D-CT and A can be incorporated in the margin expansion. The GTV expanded by A yielded GTV + resp, which was compared to iGTV in terms of overlap. Three methods for PTV generation were compared. PTV del (delineated iGTV expanded to CTV plus PTV margin), PTV σ (GTV expanded to CTV and A was included as a random uncertainty in the CTV to PTV margin) and PTV ∑ (GTV expanded to CTV, succeeded by CTV linear expansion by A to CTV + resp, which was finally expanded to PTV ∑ ). Deformation of tumor and lymph nodes during respiration resulted in volume changes between the respiratory phases. The overlap between iGTV and GTV + resp showed that on average 7% of iGTV was outside the GTV + resp implying that GTV + resp did not capture the tumor during the full deformable respiration cycle. A comparison of the PTV volumes showed that PTV σ was smallest and PTV Σ largest for all patients. PTV σ was in mean 14% (31 cm 3 ) smaller than PTV del , while PTV del was 7% (20 cm 3 ) smaller than PTV Σ . PTV σ yields the smallest volumes but does not ensure coverage of tumor during the full respiratory motion due to tumor deformation. Incorporating the respiratory motion in the delineation (PTV del ) takes into account the entire respiratory cycle including deformation, but at the cost, however, of larger treatment volumes. PTV Σ should not be used, since it incorporates the disadvantages of both PTV del and PTV σ .
Lv, Min; Fang, Renfei; Wu, Jiang; Pang, Xinghuo; Deng, Ying; Lei, Trudy; Xie, Zheng
2016-04-19
In order to improve influenza vaccination coverage, the coverage rate and reasons for non-vaccination need to be determined. In 2007, the Beijing Government published a policy providing free influenza vaccinations to elderly people living in Beijing who are older than 60. This study examines the vaccination coverage after the policy was carried out and factors influencing vaccination among the elderly in Beijing. A cross-sectional survey was conducted through the use of questionnaires in 2013. A total of 1673 eligible participants were selected by multistage stratified random sampling in Beijing using anonymous questionnaires in-person. They were surveyed to determine vaccination status and social demographic information. The influenza vaccination coverage was 38.7% among elderly people in Beijing in 2012. The most common reason for not being vaccinated was people thinking they did not need to have a flu shot. After controlling for age, gender, income, self-reported health status, and the acceptance of health promotion, the rate in rural areas was 2.566 (95% confidence interval [CI], 1.801-3.655, P<0.010) times greater than that in urban areas. Different mechanisms of health education and health promotion have different influences on vaccination uptake. Those whom received information through television, community boards, or doctors were more likely to get vaccinated compared to those who did not (Odds Ratio [OR]=1.403, P<0.010; OR=1.812, P<0.010; OR=2.647, P<0.010). The influenza vaccine coverage in Beijing is much lower than that of developed countries with similar policies. The rural-urban disparity in coverage rate (64.1% versus 33.5%), may be explained by differing health provision systems and personal attitudes toward free services due to socioeconomic factors. Methods for increasing vaccination levels include increasing the focus on primary care and health education programs, particularly recommendations from doctors, to the distinct target populations, especially with a focus on expanding these efforts in urban areas. Copyright © 2016 Elsevier Ltd. All rights reserved.
Tran, Linda Diem
2016-01-01
A difference-in-difference approach was used to compare the effects of same-sex domestic partnership, civil union, and marriage policies on same- and different-sex partners who could have benefitted from their partners’ employer-based insurance (EBI) coverage. Same-sex partners had 78% lower odds (ME=-21%) of having EBI compared to different-sex partners, adjusting for socioeconomic and health-related factors. Same-sex partners living in states that recognized same-sex marriage or domestic partnership had 89% greater odds of having EBI compared to those in states that did not recognize same-sex unions (ME=5%). The impact of same-sex legislation on increasing take-up of dependent EBI coverage among lesbians, gay men, and bisexual individuals (LGBs) was modest, and domestic partnership legislation was equally as effective as same-sex marriage in increasing same-sex partner EBI coverage. Extending dependent EBI coverage to same-sex partners can mitigate gaps in coverage for a segment of the LGB population but will not eliminate them. PMID:26762647
Bajaj, Preeti S; Veenstra, David L; Goertz, Hans-Peter; Carlson, Josh J
2014-08-01
A recent phase III trial showed that patients with advanced non-small cell lung cancer (NSCLC) whose tumors harbor specific EGFR mutations significantly benefit from first-line treatment with erlotinib compared to chemotherapy. This study sought to estimate the budget impact if coverage for EGFR testing and erlotinib as first-line therapy were provided in a hypothetical 500,000-member managed care plan. The budget impact model was developed from a US health plan perspective to evaluate administration of the EGFR test and treatment with erlotinib for EGFR-positive patients, compared to non-targeted treatment with chemotherapy. The eligible patient population was estimated from age-stratified SEER incidence data. Clinical data were derived from key randomized controlled trials. Costs related to drug, administration, and adverse events were included. Sensitivity analyses were conducted to assess uncertainty. In a plan of 500,000 members, it was estimated there would be 91 newly diagnosed advanced NSCLC patients annually; 11 are expected to be EGFR-positive. Based on the testing and treatment assumptions, it was estimated that 3 patients in Scenario 1 and 6 patients in Scenario 2 receive erlotinib. Overall health plan expenditures would increase by $0.013 per member per month (PMPM). This increase is largely attributable to erlotinib drug costs, in part due to lengthened progression-free survival and treatment periods experienced in erlotinib-treated patients. EGFR testing contributes slightly, whereas adverse event costs mitigate the budget impact. The budget impact did not exceed $0.019 PMPM in sensitivity analyses. Coverage for targeted first-line erlotinib therapy in NSCLC likely results in a small budget impact for US health plans. The estimated impact may vary by plan, or if second-line or maintenance therapy, dose changes/interruptions, or impact on patients' quality-of-life were included.
Kim, Jeehyeong; Karim, Nzabanita Abdoul; Cho, Sunghyun
2017-01-01
Device-to-Device (D2D) communication technology has become a key factor in wireless sensor networks to form autonomous communication links among sensor nodes. Many research results for D2D have been presented to resolve different technical issues of D2D. Nevertheless, the previous works have not resolved the shortage of data rate and limited coverage of wireless sensor networks. Due to bandwidth shortages and limited communication coverage, 3rd Generation Partnership Project (3GPP) has introduced a new Device-to-Device (D2D) communication technique underlying cellular networks, which can improve spectral efficiencies by enabling the direct communication of devices in proximity without passing through enhanced-NodeB (eNB). However, to enable D2D communication in a cellular network presents a challenge with regard to radio resource management since D2D links reuse the uplink radio resources of cellular users and it can cause interference to the receiving channels of D2D user equipment (DUE). In this paper, a hybrid mechanism is proposed that uses Fractional Frequency Reuse (FFR) and Almost Blank Sub-frame (ABS) schemes to handle inter-cell interference caused by cellular user equipments (CUEs) to D2D receivers (DUE-Rxs), reusing the same resources at the cell edge area. In our case, DUE-Rxs are considered as victim nodes and CUEs as aggressor nodes, since our primary target is to minimize inter-cell interference in order to increase the signal to interference and noise ratio (SINR) of the target DUE-Rx at the cell edge area. The numerical results show that the interference level of the target D2D receiver (DUE-Rx) decreases significantly compared to the conventional FFR at the cell edge. In addition, the system throughput of the proposed scheme can be increased up to 60% compared to the conventional FFR. PMID:28489064
Kim, Jeehyeong; Karim, Nzabanita Abdoul; Cho, Sunghyun
2017-05-10
Device-to-Device (D2D) communication technology has become a key factor in wireless sensor networks to form autonomous communication links among sensor nodes. Many research results for D2D have been presented to resolve different technical issues of D2D. Nevertheless, the previous works have not resolved the shortage of data rate and limited coverage of wireless sensor networks. Due to bandwidth shortages and limited communication coverage, 3rd Generation Partnership Project (3GPP) has introduced a new Device-to-Device (D2D) communication technique underlying cellular networks, which can improve spectral efficiencies by enabling the direct communication of devices in proximity without passing through enhanced-NodeB (eNB). However, to enable D2D communication in a cellular network presents a challenge with regard to radio resource management since D2D links reuse the uplink radio resources of cellular users and it can cause interference to the receiving channels of D2D user equipment (DUE). In this paper, a hybrid mechanism is proposed that uses Fractional Frequency Reuse (FFR) and Almost Blank Sub-frame (ABS) schemes to handle inter-cell interference caused by cellular user equipments (CUEs) to D2D receivers (DUE-Rxs), reusing the same resources at the cell edge area. In our case, DUE-Rxs are considered as victim nodes and CUEs as aggressor nodes, since our primary target is to minimize inter-cell interference in order to increase the signal to interference and noise ratio (SINR) of the target DUE-Rx at the cell edge area. The numerical results show that the interference level of the target D2D receiver (DUE-Rx) decreases significantly compared to the conventional FFR at the cell edge. In addition, the system throughput of the proposed scheme can be increased up to 60% compared to the conventional FFR.
Ko, Young Eun; Cho, Byungchul; Kim, Su Ssan; Song, Si Yeol; Choi, Eun Kyung; Ahn, Seung Do; Yi, Byongyong
2016-01-01
Purpose To develop a simplified volumetric modulated arc therapy (VMAT) technique for more accurate dose delivery in thoracic stereotactic body radiation therapy (SBRT). Methods and Materials For each of the 22 lung SBRT cases treated with respiratory-gated VMAT, a dose rate modulated arc therapy (DrMAT) plan was retrospectively generated. A dynamic conformal arc therapy plan with 33 adjoining coplanar arcs was designed and their beam weights were optimized by an inverse planning process. All sub-arc beams were converted into a series of control points with varying MLC segment and dose rates and merged into an arc beam for a DrMAT plan. The plan quality of original VMAT and DrMAT was compared in terms of target coverage, compactness of dose distribution, and dose sparing of organs at risk. To assess the delivery accuracy, the VMAT and DrMAT plans were delivered to a motion phantom programmed with the corresponding patients’ respiratory signal; results were compared using film dosimetry with gamma analysis. Results The plan quality of DrMAT was equivalent to that of VMAT in terms of target coverage, dose compactness, and dose sparing for the normal lung. In dose sparing for other critical organs, DrMAT was less effective than VMAT for the spinal cord, heart, and esophagus while being well within the limits specified by the Radiation Therapy Oncology Group. Delivery accuracy of DrMAT to a moving target was similar to that of VMAT using a gamma criterion of 2%/2mm but was significantly better using a 2%/1mm criterion, implying the superiority of DrMAT over VMAT in SBRT for thoracic/abdominal tumors with respiratory movement. Conclusion We developed a DrMAT technique for SBRT that produces plans of a quality similar to that achieved with VMAT but with better delivery accuracy. This technique is well-suited for small tumors with motion uncertainty. PMID:27333199
Quantifying the impact of expanded age group campaigns for polio eradication.
Wagner, Bradley G; Behrend, Matthew R; Klein, Daniel J; Upfill-Brown, Alexander M; Eckhoff, Philip A; Hu, Hao
2014-01-01
A priority of the Global Polio Eradication Initiative (GPEI) 2013-2018 strategic plan is to evaluate the potential impact on polio eradication resulting from expanding one or more Supplementary Immunization Activities (SIAs) to children beyond age five-years in polio endemic countries. It has been hypothesized that such expanded age group (EAG) campaigns could accelerate polio eradication by eliminating immunity gaps in older children that may have resulted from past periods of low vaccination coverage. Using an individual-based mathematical model, we quantified the impact of EAG campaigns in terms of probability of elimination, reduction in polio transmission and age stratified immunity levels. The model was specifically calibrated to seroprevalence data from a polio-endemic region: Zaria, Nigeria. We compared the impact of EAG campaigns, which depend only on age, to more targeted interventions which focus on reaching missed populations. We found that EAG campaigns would not significantly improve prospects for polio eradication; the probability of elimination increased by 8% (from 24% at baseline to 32%) when expanding three annual SIAs to 5-14 year old children and by 18% when expanding all six annual SIAs. In contrast, expanding only two of the annual SIAs to target hard-to-reach populations at modest vaccination coverage-representing less than one tenth of additional vaccinations required for the six SIA EAG scenario-increased the probability of elimination by 55%. Implementation of EAG campaigns in polio endemic regions would not improve prospects for eradication. In endemic areas, vaccination campaigns which do not target missed populations will not benefit polio eradication efforts.
Papagiannis, P; Karaiskos, P; Kozicki, M; Rosiak, J M; Sakelliou, L; Sandilos, P; Seimenis, I; Torrens, M
2005-05-07
This work seeks to verify multi-shot clinical applications of stereotactic radiosurgery with a Leksell Gamma Knife model C unit employing a polymer gel-MRI based experimental procedure, which has already been shown to be capable of verifying the precision and accuracy of dose delivery in single-shot gamma knife applications. The treatment plan studied in the present work resembles a clinical treatment case of pituitary adenoma using four 8 mm and one 14 mm collimator helmet shots to deliver a prescription dose of 15 Gy to the 50% isodose line (30 Gy maximum dose). For the experimental dose verification of the treatment plan, the same criteria as those used in the clinical treatment planning evaluation were employed. These included comparison of measured and GammaPlan calculated data, in terms of percentage isodose contours on axial, coronal and sagittal planes, as well as 3D plan evaluation criteria such as dose-volume histograms for the target volume, target coverage and conformity indices. Measured percentage isodose contours compared favourably with calculated ones despite individual point fluctuations at low dose contours (e.g., 20%) mainly due to the effect of T2 measurement uncertainty on dose resolution. Dose-volume histogram data were also found in a good agreement while the experimental results for the percentage target coverage and conformity index were 94% and 1.17 relative to corresponding GammaPlan calculations of 96% and 1.12, respectively. Overall, polymer gel results verified the planned dose distribution within experimental uncertainties and uncertainty related to the digitization process of selected GammaPlan output data.