An analysis of the radiation from apertures in curved surfaces by the geometrical theory of diffraction. [ray technique for electromagnetic fields

NASA Technical Reports Server (NTRS)

Pathak, P. H.; Kouyoumjian, R. G.

1974-01-01

In this paper the geometrical theory of diffraction is extended to treat the radiation from apertures of slots in convex perfectly conducting surfaces. It is assumed that the tangential electric field in the aperture is known so that an equivalent infinitesimal source can be defined at each point in the aperture. Surface rays emanate from this source which is a caustic of the ray system. A launching coefficient is introduced to describe the excitation of the surface ray modes. If the field radiated from the surface is desired, the ordinary diffraction coefficients are used to determine the field of the rays shed tangentially from the surface rays. The field of the surface ray modes is not the field on the surface; hence if the mutual coupling between slots is of interest, a second coefficient related to the launching coefficient must be employed. In the region adjacent to the shadow boundary, the component of the field directly radiated from the source is represented by Fock-type functions. In the illuminated region the incident radiation from the source (this does not include the diffracted field components) is treated by geometrical optics. This extension of the geometrical theory of diffraction is applied to calculate the radiation from slots on elliptic cylinders, spheres, and spheroids.

Comparison of doses and NTCP to risk organs with enhanced inspiration gating and free breathing for left-sided breast cancer radiotherapy using the AAA algorithm.

PubMed

Edvardsson, Anneli; Nilsson, Martin P; Amptoulach, Sousana; Ceberg, Sofie

2015-04-10

The purpose of this study was to investigate the potential dose reduction to the heart, left anterior descending (LAD) coronary artery and the ipsilateral lung for patients treated with tangential and locoregional radiotherapy for left-sided breast cancer with enhanced inspiration gating (EIG) compared to free breathing (FB) using the AAA algorithm. The radiobiological implication of such dose sparing was also investigated. Thirty-two patients, who received tangential or locoregional adjuvant radiotherapy with EIG for left-sided breast cancer, were retrospectively enrolled in this study. Each patient was CT-scanned during FB and EIG. Similar treatment plans, with comparable target coverage, were created in the two CT-sets using the AAA algorithm. Further, the probability of radiation induced cardiac mortality and pneumonitis were calculated using NTCP models. For tangential treatment, the median V25Gy for the heart and LAD was decreased for EIG from 2.2% to 0.2% and 40.2% to 0.1% (p < 0.001), respectively, whereas there was no significant difference in V20Gy for the ipsilateral lung (p = 0.109). For locoregional treatment, the median V25Gy for the heart and LAD was decreased for EIG from 3.3% to 0.2% and 51.4% to 5.1% (p < 0.001), respectively, and the median ipsilateral lung V20Gy decreased from 27.0% for FB to 21.5% (p = 0.020) for EIG. The median excess cardiac mortality probability decreased from 0.49% for FB to 0.02% for EIG (p < 0.001) for tangential treatment and from 0.75% to 0.02% (p < 0.001) for locoregional treatment. There was no significant difference in risk of radiation pneumonitis for tangential treatment (p = 0.179) whereas it decreased for locoregional treatment from 6.82% for FB to 3.17% for EIG (p = 0.004). In this study the AAA algorithm was used for dose calculation to the heart, LAD and left lung when comparing the EIG and FB techniques for tangential and locoregional radiotherapy of breast cancer patients. The results support the dose and NTCP reductions reported in previous studies where dose calculations were performed using the pencil beam algorithm.

Resonances, radiation pressure and optical scattering phenomena of drops and bubbles

NASA Technical Reports Server (NTRS)

Marston, P. L.; Goosby, S. G.; Langley, D. S.; Loporto-Arione, S. E.

1982-01-01

Acoustic levitation and the response of fluid spheres to spherical harmonic projections of the radiation pressure are described. Simplified discussions of the projections are given. A relationship between the tangential radiation stress and the Konstantinov effect is introduced and fundamental streaming patterns for drops are predicted. Experiments on the forced shape oscillation of drops are described and photographs of drop fission are displayed. Photographs of critical angle and glory scattering by bubbles and rainbow scattering by drops are displayed.

Positive versus negative sentinel nodes in early breast cancer patients: axillary or loco-regional relapse and survival. A study spanning 2000-2012.

PubMed

García Fernández, A; Chabrera, C; García Font, M; Fraile, M; Lain, J M; Barco, I; González, C; Gónzalez, S; Reñe, A; Veloso, E; Cassadó, J; Pessarrodona, A; Giménez, N

2013-10-01

Sentinel Node Biopsy (SNB) is a minimally invasive alternative to elective axillary lymph node dissection (ALND) for nodal staging in early breast cancer. The present study was conducted to evaluate prognostic implications of a negative sentinel node (SN) versus a positive SN (followed by completion ALND) in a closely followed-up sample of early breast cancer patients. We studied 889 consecutive breast cancer patients operated for 908 primaries. Patients received adjuvant therapy with chemotherapy, hormone therapy and eventually trastuzumab. Radiation therapy was based on tangential radiation fields that usually included axillary level I. Median follow-up was 47 months. Axillary recurrence was seen in 1.2% (2/162) of positive SN patients, and 0.8% (5/625) of negative SN patients (p = n.s.). There was an overall 3.2% loco-regional failure rate (29/908). Incidence of distant recurrence was 3.3% (23/693) for negative SN patients, and 4.6% (9/196) for positive SN patients (p = n.s.). Overall mortality rate was 4% (8/198) for positive SN patients, while the corresponding specific mortality rate was 2.5% (5/198). For patients with negative SNs, overall mortality was 4.9% (34/693), and the specific mortality was 1.4% (19/693) (p = n.s.). We did not find significant differences in axillary/loco-regional relapse, distant metastases, disease-free interval or mortality between SN negative and SN positive patients, with a follow-up over 4 years. Copyright © 2013 Elsevier Ltd. All rights reserved.

Comparison of setup accuracy of three different image assessment methods for tangential breast radiotherapy.

PubMed

Batumalai, Vikneswary; Phan, Penny; Choong, Callie; Holloway, Lois; Delaney, Geoff P

2016-12-01

To compare the differences in setup errors measured with electronic portal image (EPI) and cone-beam computed tomography (CBCT) in patients undergoing tangential breast radiotherapy (RT). Relationship between setup errors, body mass index (BMI) and breast size was assessed. Twenty-five patients undergoing postoperative RT to the breast were consented for this study. Weekly CBCT scans were acquired and retrospectively registered to the planning CT in three dimensions, first using bony anatomy for bony registration (CBCT-B) and again using breast tissue outline for soft tissue registration (CBCT-S). Digitally reconstructed radiographs (DRR) generated from CBCT to simulate EPI were compared to the planning DRR using bony anatomy in the V (parallel to the cranio-caudal axis) and U (perpendicular to V) planes. The systematic (Σ) and random (σ) errors were calculated and correlated with BMI and breast size. The systematic and random errors for EPI (Σ V = 3.7 mm, Σ U = 2.8 mm and σ V = 2.9 mm, σ U = 2.5) and CBCT-B (Σ V = 3.5 mm, Σ U = 3.4 mm and σ V = 2.8 mm, σ U = 2.8) were of similar magnitude in the V and U planes. Similarly, the differences in setup errors for CBCT-B and CBCT-S in three dimensions were less than 1 mm. Only CBCT-S setup error correlated with BMI and breast size. CBCT and EPI show insignificant variation in their ability to detect setup error. These findings suggest no significant differences that would make one modality considered superior over the other and EPI should remain the standard of care for most patients. However, there is a correlation with breast size, BMI and setup error as detected by CBCT-S, justifying the use of CBCT-S for larger patients. © 2016 The Authors. Journal of Medical Radiation Sciences published by John Wiley & Sons Australia, Ltd on behalf of Australian Society of Medical Imaging and Radiation Therapy and New Zealand Institute of Medical Radiation Technology.

Uncertainties in estimating heart doses from 2D-tangential breast cancer radiotherapy.

PubMed

Lorenzen, Ebbe L; Brink, Carsten; Taylor, Carolyn W; Darby, Sarah C; Ewertz, Marianne

2016-04-01

We evaluated the accuracy of three methods of estimating radiation dose to the heart from two-dimensional tangential radiotherapy for breast cancer, as used in Denmark during 1982-2002. Three tangential radiotherapy regimens were reconstructed using CT-based planning scans for 40 patients with left-sided and 10 with right-sided breast cancer. Setup errors and organ motion were simulated using estimated uncertainties. For left-sided patients, mean heart dose was related to maximum heart distance in the medial field. For left-sided breast cancer, mean heart dose estimated from individual CT-scans varied from <1Gy to >8Gy, and maximum dose from 5 to 50Gy for all three regimens, so that estimates based only on regimen had substantial uncertainty. When maximum heart distance was taken into account, the uncertainty was reduced and was comparable to the uncertainty of estimates based on individual CT-scans. For right-sided breast cancer patients, mean heart dose based on individual CT-scans was always <1Gy and maximum dose always <5Gy for all three regimens. The use of stored individual simulator films provides a method for estimating heart doses in left-tangential radiotherapy for breast cancer that is almost as accurate as estimates based on individual CT-scans. Copyright © 2016. Published by Elsevier Ireland Ltd.

Automated planning of tangential breast intensity-modulated radiotherapy using heuristic optimization.

PubMed

Purdie, Thomas G; Dinniwell, Robert E; Letourneau, Daniel; Hill, Christine; Sharpe, Michael B

2011-10-01

To present an automated technique for two-field tangential breast intensity-modulated radiotherapy (IMRT) treatment planning. A total of 158 planned patients with Stage 0, I, and II breast cancer treated using whole-breast IMRT were retrospectively replanned using automated treatment planning tools. The tools developed are integrated into the existing clinical treatment planning system (Pinnacle(3)) and are designed to perform the manual volume delineation, beam placement, and IMRT treatment planning steps carried out by the treatment planning radiation therapist. The automated algorithm, using only the radio-opaque markers placed at CT simulation as inputs, optimizes the tangential beam parameters to geometrically minimize the amount of lung and heart treated while covering the whole-breast volume. The IMRT parameters are optimized according to the automatically delineated whole-breast volume. The mean time to generate a complete treatment plan was 6 min, 50 s ± 1 min 12 s. For the automated plans, 157 of 158 plans (99%) were deemed clinically acceptable, and 138 of 158 plans (87%) were deemed clinically improved or equal to the corresponding clinical plan when reviewed in a randomized, double-blinded study by one experienced breast radiation oncologist. In addition, overall the automated plans were dosimetrically equivalent to the clinical plans when scored for target coverage and lung and heart doses. We have developed robust and efficient automated tools for fully inversed planned tangential breast IMRT planning that can be readily integrated into clinical practice. The tools produce clinically acceptable plans using only the common anatomic landmarks from the CT simulation process as an input. We anticipate the tools will improve patient access to high-quality IMRT treatment by simplifying the planning process and will reduce the effort and cost of incorporating more advanced planning into clinical practice. Crown Copyright © 2011. Published by Elsevier Inc. All rights reserved.

A comparative analysis of 3D conformal deep inspiratory–breath hold and free-breathing intensity-modulated radiation therapy for left-sided breast cancer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Reardon, Kelli A.; Read, Paul W.; Morris, Monica M.

2013-07-01

Patients undergoing radiation for left-sided breast cancer have increased rates of coronary artery disease. Free-breathing intensity-modulated radiation therapy (FB-IMRT) and 3-dimensional conformal deep inspiratory–breath hold (3D-DIBH) reduce cardiac irradiation. The purpose of this study is to compare the dose to organs at risk in FB-IMRT vs 3D-DIBH for patients with left-sided breast cancer. Ten patients with left-sided breast cancer had 2 computed tomography scans: free breathing and voluntary DIBH. Optimization of the IMRT plan was performed on the free-breathing scan using 6 noncoplanar tangential beams. The 3D-DIBH plan was optimized on the DIBH scan and used standard tangents. Mean volumesmore » of the heart, the left anterior descending coronary artery (LAD), the total lung, and the right breast receiving 5% to 95% (5% increments) of the prescription dose were calculated. Mean volumes of the heart and the LAD were lower (p<0.05) in 3D-DIBH for volumes receiving 5% to 80% of the prescription dose for the heart and 5% for the LAD. Mean dose to the LAD and heart were lower in 3D-DIBH (p≤0.01). Mean volumes of the total lung were lower in FB-IMRT for dose levels 20% to 75% (p<0.05), but mean dose was not different. Mean volumes of the right breast were not different for any dose; however, mean dose was lower for 3D-DIBH (p = 0.04). 3D-DIBH is an alternative approach to FB-IMRT that provides a clinically equivalent treatment for patients with left-sided breast cancer while sparing organs at risk with increased ease of implementation.« less

Energy optimization in gold nanoparticle enhanced radiation therapy.

PubMed

Sung, Wonmo; Schuemann, Jan

2018-06-25

Gold nanoparticles (GNPs) have been demonstrated as radiation dose enhancing agents. Kilovoltage external photon beams have been shown to yield the largest enhancement due to the high interaction probability with gold. While orthovoltage irradiations are feasible and promising, they suffer from a reduced tissue penetrating power. This study quantifies the effect of varying photon beam energies on various beam arrangements, body, tumor, and cellular GNP uptake geometries. Cell survival was modeled based on our previously developed GNP-local effect model with radial doses calculated using the TOPAS-nBio Monte Carlo code. Cell survival curves calculated for tumor sites with GNPs were used to calculate the relative biological effectiveness (RBE)-weighted dose. In order to evaluate the plan quality, the ratio of the mean dose between the tumor and normal tissue for 50-250 kVp beams with GNPs was compared to the standard of care using 6 MV photon beams without GNPs for breast and brain tumors. For breast using a single photon beam, kV  +  GNP was found to yield up to 2.73 times higher mean RBE-weighted dose to the tumor than two tangential megavoltage beams while delivering the same dose to healthy tissue. For irradiation of brain tumors using multiple photon beams, the GNP dose enhancement was found to be effective for energies above 50 keV. A small tumor at shallow depths was found to be the most effective treatment conditions for GNP enhanced radiation therapy. GNP uptake distributions in the cell (with or without nuclear uptake) and the beam arrangement were found to be important factors in determining the optimal photon beam energy.

Evaluation of the peripheral dose to uterus in breast carcinoma radiotherapy.

PubMed

Martín Rincón, C; Jerez Sainz, I; Modolell Farré, I; España López, M L; López Franco, P; Muñiz, J L; Romero, A M; Rodríguez, R

2002-01-01

The absorbed dose outside of the direct fields of radiotherapy treatment (or peripheral dose, PD) is responsible for radiation exposure of the fetus in pregnant women. Because the radiological protection of the unborn child is of particular concern in the early period of the pregnancy, the aim of this study is to estimate the PD in order to assess the absorbed dose in the uterus in a pregnant patient irradiated for breast carcinoma therapy. The treatment was simulated on an Alderson-Rando anthropomorphic phantom, and the radiation dose to the fetus was measured using an ionisation chamber and thermoluminescence dosemeters. Two similar treatments plans with and without wedges were delivered, using a 6 MV photon beam with two isocentric opposite tangential fields with a total dose of 50 Gy, in accordance with common established procedures. Average field parameters for more than 300 patients were studied. Measurements showed the fetal dose to be slightly lower than 50 mGy, a level at which the risk to the fetus is uncertain, although several authors consider this value as the dose threshold for deterministic effects. The planning system (PS) underestimated PD values and no significant influence was found with the use of wedge filters.

Bilateral implant reconstruction does not affect the quality of postmastectomy radiation therapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ho, Alice Y., E-mail: hoa1234@mskcc.org; Patel, Nisha; Ohri, Nisha

To determine if the presence of bilateral implants, in addition to other anatomic and treatment-related variables, affects coverage of the target volume and dose to the heart and lung in patients receiving postmastectomy radiation therapy (PMRT). A total of 197 consecutive women with breast cancer underwent mastectomy and immediate tissue expander (TE) placement, with or without exchange for a permanent implant (PI) before radiation therapy at our center. PMRT was delivered with 2 tangential beams + supraclavicular lymph node field (50 Gy). Patients were grouped by implant number: 51% unilateral (100) and 49% bilateral (97). The planning target volume (PTV)more » (defined as implant + chest wall + nodes), heart, and ipsilateral lung were contoured and the following parameters were abstracted from dose-volume histogram (DVH) data: PTV D{sub 95%} > 98%, Lung V{sub 20}Gy > 30%, and Heart V{sub 25}Gy > 5%. Univariate (UVA) and multivariate analyses (MVA) were performed to determine the association of variables with these parameters. The 2 groups were well balanced for implant type and volume, internal mammary node (IMN) treatment, and laterality. In the entire cohort, 90% had PTV D{sub 95%} > 98%, indicating excellent coverage of the chest wall. Of the patients, 27% had high lung doses (V{sub 20}Gy > 30%) and 16% had high heart doses (V{sub 25}Gy > 5%). No significant factors were associated with suboptimal PTV coverage. On MVA, IMN treatment was found to be highly associated with high lung and heart doses (both p < 0.0001), but implant number was not (p = 0.54). In patients with bilateral implants, IMN treatment was the only predictor of dose to the contralateral implant (p = 0.001). In conclusion, bilateral implants do not compromise coverage of the target volume or increase lung and heart dose in patients receiving PMRT. The most important predictor of high lung and heart doses in patients with implant-based reconstruction, whether unilateral or bilateral, is treatment of the IMNs. Refinement of radiation techniques in reconstructed patients who require comprehensive nodal irradiation is warranted.« less

Building a New Model of Care for Rapid Breast Radiotherapy Treatment Planning: Evaluation of the Advanced Practice Radiation Therapist in Cavity Delineation.

PubMed

Lee, G; Dinniwell, R; Liu, F F; Fyles, A; Han, K; Conrad, T; Levin, W; Marshall, A; Purdie, T G; Koch, C A

2016-12-01

Breast radiotherapy treatment is commonly managed by a multidisciplinary team to ensure optimal delivery of care. We sought a new model of care whereby a clinical specialist radiation therapist (CSRT) delineates the cavity target for whole breast radiotherapy treatment planning and the radiation oncologist validates the contour during final plan review. This study evaluated the radiation oncologist's acceptance of these contours and identified characteristics of cavities suitable for CSRT-directed contouring. Following specialised breast oncology education and training by the radiation oncologist, the CSRT prospectively delineated cavities in 30 tangential breast radiotherapy cases and consulted the radiation oncologist in 'complex' cases but directed 'non-complex' cases for treatment planning. Changes to CSRT contours were evaluated using the conformity index. Breast density, time since surgery and cavity location, size and visualisation score [CVS: range 1 (no visible cavity) to 5 (homogenous cavity)] were captured. Of the 30 CSRT delineated cavities contours, the CSRT directed 20 (66.7%) cases for planning without radiation oncology review; 19 were accepted (without changes) by the radiation oncologist upon final plan review and one was changed by the radiation oncologist (conformity index = 0.93) for boost treatment and did not affect the tangential treatment plan. Ten (33.3%) cases, all CVS ≤ 3, were reviewed with the radiation oncologist before planning (conformity index = 0.88 ± 0.12). CVS was inversely correlated with breast density and cavity size (P < 0.01). The CSRT delineated cavities appropriate for clinical radiotherapy treatment planning in women with well-visualised cavities, whereas 'complex' cases with dense breast parenchyma, CVS ≤ 3, and/or cases needing boost radiotherapy treatment required review with the radiation oncologist before planning. Copyright © 2016 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

[Does nodal irradiation (clavicular and internal mammary chains) increase the toxicity of adjuvant breast radiotherapy?].

PubMed

Riou, O; Bourgier, C; Fenoglietto, P; Azria, D

2015-06-01

Treatment volume is a major risk factor of radiation-induced toxicity. As nodal irradiation increases treatment volume, radiation toxicity should be greater. Nevertheless, scientific randomised data do not support this fact. However, a radiation-induced toxicity is possible outside tangential fields in the nodal volumes not related to breast-only treatment. Treatment should not be adapted only to the disease but personalized to the individual risk of toxicity for each patient. Copyright © 2015 Société française de radiothérapie oncologique (SFRO). Published by Elsevier SAS. All rights reserved.

Tangential System of Thomson Scattering for Tokamak T-15

NASA Astrophysics Data System (ADS)

Asadulin, G. M.; Bel'bas, I. S.; Gorshkov, A. V.

2017-12-01

Two systems of Thomson scattering diagnostics, with vertical and tangential probing, are used in the D-shaped plasma cross section in tokamak T-15. The tangential system allows measuring plasma temperature and density profiles along the major radius of the tokamak. This paper presents the tangential system project. The system is based on a Nd:YAG laser with wavelength of 1064 nm, pulse energy of 3 J, pulse duration of 10 ns, and repetition rate of 100 Hz. The chosen geometry allows collecting light from ten uniformly spaced points. Optimization of the registration system has been accomplished. The collected light will be transmitted through an optical fiber bundle with diameter of 3 mm and quartz fibers (numerical aperture is 0.22). Six-channel polychromators based on high-contrast interference filters have been chosen as spectral equipment. The radiation will be registered by avalanche photodiodes. The technique of electron temperature and density measurement is described, and estimation of its accuracy is carried out. The proposed system allows measuring the electron temperature with accuracy not worse than 10% within the range of 50 eV to 10 keV on the pinch edge over the internal contour, from 20 eV to 9 keV in the plasma central region, and from 2 eV to 400 eV on the pinch edge over the outer contour. The estimation is made for electron density of not less than 2.6 × 1013 cm-3.

SU-E-P-56: Dosimetric Comparison of Three Post Modified Radical Mastectomy Radiotherapy Techniques for Locally Advanced Left-Sided Breast Cancer and Beyond

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

Observation of runaway electron beams by visible color camera in the Experimental Advanced Superconducting Tokamak

NASA Astrophysics Data System (ADS)

Shi, Yuejiang; Fu, Jia; Li, Jiahong; Yang, Yu; Wang, Fudi; Li, Yingying; Zhang, Wei; Wan, Baonian; Chen, Zhongyong

2010-03-01

The synchrotron radiation originated from the energetic runaway electrons has been measured by a visible complementary metal oxide semiconductor camera working in the wavelength ranges of 380-750 nm in the Experimental Advanced Superconducting Tokamak [H. Q. Liu et al., Plasma Phys. Contr. Fusion 49, 995 (2007)]. With a tangential viewing into the plasma in the direction of electron approach on the equatorial plane, the synchrotron radiation from the energetic runaway electrons was measured in full poloidal cross section. The synchrotron radiation diagnostics provides a direct pattern of the runaway beam inside the plasma. The energy and pitch angle of runaway electrons have been obtained according to the synchrotron radiation pattern. A stable shell shape of synchrotron radiation has been observed in a few runaway discharges.

Evaluation of Breast Sentinel Lymph Node Coverage by Standard Radiation Therapy Fields

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rabinovitch, Rachel; Ballonoff, Ari; Newman, Francis M.S.

2008-04-01

Background: Biopsy of the breast sentinel lymph node (SLN) is now a standard staging procedure for early-stage invasive breast cancer. The anatomic location of the breast SLN and its relationship to standard radiation fields has not been described. Methods and Materials: A retrospective review of radiotherapy treatment planning data sets was performed in patients with breast cancer who had undergone SLN biopsy, and those with a surgical clip at the SLN biopsy site were identified. The location of the clip was evaluated relative to vertebral body level on an anterior-posterior digitally reconstructed radiograph, treated whole-breast tangential radiation fields, and standardmore » axillary fields in 106 data sets meeting these criteria. Results: The breast SLN varied in vertebral body level position, ranging from T2 to T7 but most commonly opposite T4. The SLN clip was located below the base of the clavicle in 90%, and hence would be excluded from standard axillary radiotherapy fields where the inferior border is placed at this level. The clip was within the irradiated whole-breast tangent fields in 78%, beneath the superior-posterior corner multileaf collimators in 12%, and outside the tangent field borders in 10%. Conclusions: Standard axillary fields do not encompass the lymph nodes at highest risk of containing tumor in breast cancer patients. Elimination of the superior-posterior corner MLCs from the tangent field design would result in inclusion of the breast SLN in 90% of patients treated with standard whole-breast irradiation.« less

SU-C-213-05: Evaluation of a Composite Copper-Plastic Material for a 3D Printed Radiation Therapy Bolus

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vitzthum, L; Ehler, E; Sterling, D

2015-06-15

Purpose: To evaluate a novel 3D printed bolus fabricated from a copper-plastic composite as a thin flexible, custom fitting device that can replicate doses achieved with conventional bolus techniques. Methods: Two models of bolus were created on a 3D printer using a composite copper-PLA/PHA. Firstly, boluses were constructed at thicknesses of 0.4, 0.6 and 0.8 mm. Relative dose measurements were performed under the bolus with an Attix Chamber as well as with radiochromic film. Results were compared to superficial Attix Chamber measurements in a water equivalent material to determine the dosimetric water equivalence of the copper-PLA/PHA plastic. Secondly, CT imagesmore » of a RANDO phantom were used to create a custom fitting bolus across the anterolateral scalp. Surface dose with the bolus placed on the RANDO phantom was measured with radiochromic film at tangential angles with 6, 10, 10 flattening filter free (FFF) and 18 MV photon beams. Results: Mean surface doses for 6, 10, 10FFF and 18 MV were measured as a percent of Dmax for the flat bolus devices of each thickness. The 0.4 mm thickness bolus was determined to be near equivalent to 2.5 mm depth in water for all four energies. Surface doses ranged from 59–63% without bolus and 85–90% with the custom 0.4 mm copper-plastic bolus relative to the prescribed dose for an oblique tangential beam arrangement on the RANDO phantom. Conclusion: Sub-millimeter thickness, 3D printed composite copper-PLA/PHA bolus can provide a build-up effect equivalent to conventional bolus. At this thickness, the 3D printed bolus allows a level of flexure that may provide more patient comfort than current 3D printing materials used in bolus fabrication while still retaining the CT based custom patient shape. Funding provided by an intra-department grant of the University of Minnesota Department of Radiation Oncology.« less

Simultaneous integrated boost (SIB) radiation therapy of right sided breast cancer with and without flattening filter - A treatment planning study.

PubMed

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.

Dosimetry around metallic ports in tissue expanders in patients receiving postmastectomy radiation therapy: an ex vivo evaluation.

PubMed

Moni, Janaki; Graves-Ditman, Maria; Cederna, Paul; Griffith, Kent; Krueger, Editha A; Fraass, Benedick A; Pierce, Lori J

2004-01-01

Postmastectomy breast reconstruction can be accomplished utilizing tissue expanders and implants. However, in patients who require postoperative radiotherapy, the complication rate with tissue expander/implant reconstruction can exceed 50%. One potential cause of this high complication rate may be the metallic port in the tissue expander producing altered dosimetry in the region of the metallic device. The purpose of this study was to quantify the radiation dose distribution in the vicinity of the metallic port and determine its potential contribution to this extremely high complication rate. The absolute dosimetric effect of the tissue expander's metallic port was quantified using film and thermoluminescent dosimetry (TLD) studies with a single beam incident on a metallic port extracted from an expander. TLD measurements were performed at 11 reproducible positions on an intact expander irradiated with tangential fields. A computed tomography (CT)-based treatment plan without inhomogeneity corrections was used to derive expected doses for all TLD positions. Multiple irradiation experiments were performed for all TLD data. Confidence intervals for the dose at TLD sites with the metallic port in place were compared to the expected dose at the site without the metallic port. Film studies did not reveal a significant component of scatter around the metallic port. TLD studies of the extracted metallic port revealed highest doses within the casing of the metallic port and no consistent increased dose at the surface of the expander. No excess dose due to the metallic port in the expander was noted with the phantom TLD data. Based upon these results, it does not appear that the metallic port in tissue expanders significantly contributes to the high complication rate experienced in patients undergoing tissue expander breast reconstruction and receiving radiation therapy. Strategies designed to reduce the breast reconstruction complication rate in this clinical setting will need to focus on factors other than adjusting the dosimetry around the tissue expander metallic port.

Impact of Sequencing Radiation Therapy and Chemotherapy on Long-Term Local Toxicity for Early Breast Cancer: Results of a Randomized Study at 15-Year Follow-Up

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pinnarò, Paola; Giordano, Carolina; Farneti, Alessia

Purpose: To compare long-term late local toxicity after either concomitant or sequential chemoradiation therapy after breast-conserving surgery. Methods and Materials: From 1997 to 2002, women aged 18 to 75 years who underwent breast-conserving surgery and axillary dissection for early breast cancer and in whom CMF (cyclophosphamide, methotrexate, and 5-fluorouracil) chemotherapy was planned were randomized between concomitant and sequential radiation therapy. Radiation therapy was delivered to the whole breast through tangential fields to 50 Gy in 20 fractions over a period of 4 weeks, followed by an electron boost. Surviving patients were tentatively contacted and examined between March and September 2014. Patients in whom progressive diseasemore » had developed or who had undergone further breast surgery were excluded. Local toxicity (fibrosis, telangiectasia, and breast atrophy or retraction) was scored blindly to the treatment received. A logistic regression was run to investigate the effect of treatment sequence after correction for several patient-, treatment-, and tumor-related covariates on selected endpoints. The median time to cross-sectional analysis was 15.7 years (range, 12.0-17.8 years). Results: Of 206 patients randomized, 154 (74.8%) were potentially eligible. Of these, 43 (27.9%) refused participation and 4 (2.6%) had been lost to follow-up, and for 5 (3.2%), we could not restore planning data; thus, the final number of analyzed patients was 102. No grade 4 toxicity had been observed, whereas the number of grade 3 toxicity events was low (<8%) for each item, allowing pooling of grade 2 and 3 events for further analysis. Treatment sequence (concomitant vs sequential) was an independent predictor of grade 2 or 3 fibrosis according to both the National Cancer Institute Common Terminology Criteria for Adverse Events (odds ratio [OR], 4.05; 95% confidence interval [CI], 1.34-12.2; P=.013) and the SOMA (Subjective, Objective, Management and Analytic) scale (OR, 3.75; 95% CI, 1.19-11.79; P=.018), as well as grade 2 or 3 breast atrophy or retraction (OR, 3.87; 95% CI, 1.42-10.56; P=.008). No effect on telangiectasia was detected. Conclusions: At long-term follow-up, concomitant chemoradiation therapy has a detrimental effect on both fibrosis and retraction with an approximately 4-fold increase in the odds of grade 2 or 3 toxicity.« less

Intensity modulated radiotherapy with fixed collimator jaws for locoregional left-sided breast cancer irradiation.

PubMed

Wang, Juanqi; Yang, Zhaozhi; Hu, Weigang; Chen, Zhi; Yu, Xiaoli; Guo, Xiaomao

2017-05-16

The purpose of this study is to evaluate the intensity modulated radiotherapy (IMRT) with the fixed collimator jaws technique (FJT) for the left breast and regional lymph node. The targeted breast tissue and the lymph nodes, and the normal tissues were contoured for 16 left-sided breast cancer patients previously treated with radiotherapy after lumpectomy. For each patient, treatment plans using different planning techniques, i.e., volumetric modulated arc therapy (VMAT), tangential IMRT (tangential-IMRT), and IMRT with FJT (FJT-IMRT) were developed for dosimetric comparisons. A dose of 50Gy was prescribed to the planning target volume. The dose-volume histograms were generated, and the paired t-test was used to analyze the dose differences. FJT-IMRT had similar mean heart volume receiving 30Gy (V30 Gy) with tangential-IMRT (1.5% and 1.6%, p = 0.41), but inferior to the VMAT (0.8%, p < 0.001). In the average heart mean dose comparison, FJT-IMRT had the lowest value, and it was 0.6Gy lower than that for the VMAT plans (p < 0.01). A significant dose increase in the contralateral breast and lung was observed in VMAT plans. Compared with tangential-IMRT and VMAT plans, FJT-IMRT reduced the mean dose of thyroid, humeral head and cervical esophageal by 47.6% (p < 0.01) and 45.7% (p < 0.01), 74.3% (p =< 0.01) and 73% (p =< 0.01), and 26.7% (p =< 0.01) and 29.2% (p =< 0.01). In conclusion, compared with tangential-IMRT and VMAT, FJT-IMRT plan has the lowest thyroid, humeral head and cervical esophageal mean dose and it can be a reasonable treatment option for a certain subgroup of patients, such as young left-breast cancer patients and/or patients with previous thyroid disease.

Preliminary design of a tangentially viewing imaging bolometer for NSTX-U

DOE Office of Scientific and Technical Information (OSTI.GOV)

Peterson, B. J., E-mail: peterson@LHD.nifs.ac.jp; Mukai, K.; SOKENDAI

2016-11-15

The infrared imaging video bolometer (IRVB) measures plasma radiated power images using a thin metal foil. Two different designs with a tangential view of NSTX-U are made assuming a 640 × 480 (1280 × 1024) pixel, 30 (105) fps, 50 (20) mK, IR camera imaging the 9 cm × 9 cm × 2 μm Pt foil. The foil is divided into 40 × 40 (64 × 64) IRVB channels. This gives a spatial resolution of 3.4 (2.2) cm on the machine mid-plane. The noise equivalent power density of the IRVB is given as 113 (46) μW/cm{sup 2} for a timemore » resolution of 33 (20) ms. Synthetic images derived from Scrape Off Layer Plasma Simulation data using the IRVB geometry show peak signal levels ranging from ∼0.8 to ∼80 (∼0.36 to ∼26) mW/cm{sup 2}.« less

Preliminary design of a tangentially viewing imaging bolometer for NSTX-U

DOE PAGES

Peterson, B. J.; Sano, R.; Reinke, M. L.; ...

2016-08-03

The InfraRed imaging Video Bolometer measures plasma radiated power images using a thin metal foil. Two different designs with a tangential view of NSTX-U are made assuming a 640 x 480 (1280 x 1024) pixel, 30 (105) fps, 50 (20) mK, IR camera imaging the 9 cm x 9 cm x 2 μm Pt foil. The foil is divided into 40 x 40 (64 x 64) IRVB channels. This gives a spatial resolution of 3.4 (2.2) cm on the machine mid-plane. The noise equivalent power density of the IRVB is given as 113 (46) μW/cm 2 for a time resolutionmore » of 33 (20) ms. Synthetic images derived from SOLPS data using the IRVB geometry show peak signal levels ranging from ~0.8 - ~80 (~0.36 - ~26) mW/cm 2.« less

Bi-tangential hybrid IMRT for sparing the shoulder in whole breast irradiation.

PubMed

Farace, P; Deidda, M A; Iamundo de Cumis, I; Iamundo de Curtis, I; Deiana, E; Farigu, R; Lay, G; Porru, S

2013-11-01

A bi-tangential technique is proposed to reduce undesired doses to the shoulder produced by standard tangential irradiation. A total of 6 patients affected by shoulder pain and reduced functional capacity after whole-breast irradiation were retrospectively analysed. The standard tangential plan used for treatment was compared with (1) a single bi-tangential plan where, to spare the shoulder, the lateral open tangent was split into two half-beams at isocentre, with the superior portion rotated by 10-20° medially with respect to the standard lateral beam; (2) a double bi-tangential plan, where both the tangential open beams were split. The planning target volume (PTV) coverage and the dose to the portion of muscles and axilla included in the standard tangential beams were compared. PTV95 % of standard plan (91.9 ± 3.8) was not significantly different from single bi-tangential plan (91.8 ± 3.4); a small but significant (p < 0.01) decrease was observed with the double bi-tangential plan (90.1 ± 3.7). A marked dose reduction to the muscle was produced by the single bi-tangential plan around 30-40 Gy. The application of the double bi-tangential technique further reduced the volume receiving around 20 Gy, but did not markedly affect the higher doses. The dose to the axilla was reduced both in the single and the double bi-tangential plans. The single bi-tangential technique would have been able to reduce the dose to shoulder and axilla, without compromising target coverage. This simple technique is valuable for irradiation after axillary lymph node dissection or in patients without dissection due to negative or low-volume sentinel lymph node disease.

Comparison of two extracorporeal shock wave therapy techniques for the treatment of painful subcalcaneal spur. A randomized controlled study.

PubMed

Tornese, Davide; Mattei, Enrico; Lucchesi, Giampaolo; Bandi, Marco; Ricci, Gabriele; Melegati, Gianluca

2008-09-01

To describe and compare two extracorporeal shock wave therapy techniques for the treatment of painful subcalcaneal spur. Random assignment to two groups of treatment with two and eight months follow-up. The data were collected in outpatients. Forty-five subjects with a history of at least six months of heel pain were studied. Each subject received a three-session ultrasound-guided extracorporeal shock wave therapy (performed weekly). Perpendicular technique was used in group A (n=22, mean age 59.3 +/- 12 years) and tangential technique was used in group B (n= 23, mean age 58.8 +/- 12.3 years). Mayo Clinical Scoring System was used to evaluate each subject before the treatment and at two and eight months follow-up. Mayo Clinical Scoring System pretreatment scores were homogeneous between the groups (group A 55.2 +/-18.7; group B 53.5 +/- 20; P>0.05). In both groups there was a significant (P<0.05) increase in the Mayo Clinical Scoring System score at two months (group A 83.9 +/- 13.7; group B 80 +/- 15,8) and eight months (group A 90 +/- 10.5; group B 90.2 +/-8.7) follow-up. No significant differences were obtained comparing the Mayo Clinical Scoring System scores of the two groups at two and eight months follow-up. There was no difference between the two techniques of using extracorporeal shock wave therapy. The tangential technique was found to be better tolerated as regards treatment-induced pain, allowing higher energy dosages to be used.

Robust optimization methods for cardiac sparing in tangential breast IMRT

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mahmoudzadeh, Houra, E-mail: houra@mie.utoronto.ca; Lee, Jenny; Chan, Timothy C. Y.

Purpose: In left-sided tangential breast intensity modulated radiation therapy (IMRT), the heart may enter the radiation field and receive excessive radiation while the patient is breathing. The patient’s breathing pattern is often irregular and unpredictable. We verify the clinical applicability of a heart-sparing robust optimization approach for breast IMRT. We compare robust optimized plans with clinical plans at free-breathing and clinical plans at deep inspiration breath-hold (DIBH) using active breathing control (ABC). Methods: Eight patients were included in the study with each patient simulated using 4D-CT. The 4D-CT image acquisition generated ten breathing phase datasets. An average scan was constructedmore » using all the phase datasets. Two of the eight patients were also imaged at breath-hold using ABC. The 4D-CT datasets were used to calculate the accumulated dose for robust optimized and clinical plans based on deformable registration. We generated a set of simulated breathing probability mass functions, which represent the fraction of time patients spend in different breathing phases. The robust optimization method was applied to each patient using a set of dose-influence matrices extracted from the 4D-CT data and a model of the breathing motion uncertainty. The goal of the optimization models was to minimize the dose to the heart while ensuring dose constraints on the target were achieved under breathing motion uncertainty. Results: Robust optimized plans were improved or equivalent to the clinical plans in terms of heart sparing for all patients studied. The robust method reduced the accumulated heart dose (D10cc) by up to 801 cGy compared to the clinical method while also improving the coverage of the accumulated whole breast target volume. On average, the robust method reduced the heart dose (D10cc) by 364 cGy and improved the optBreast dose (D99%) by 477 cGy. In addition, the robust method had smaller deviations from the planned dose to the accumulated dose. The deviation of the accumulated dose from the planned dose for the optBreast (D99%) was 12 cGy for robust versus 445 cGy for clinical. The deviation for the heart (D10cc) was 41 cGy for robust and 320 cGy for clinical. Conclusions: The robust optimization approach can reduce heart dose compared to the clinical method at free-breathing and can potentially reduce the need for breath-hold techniques.« less

Space shuttle rendezous, radiation and reentry analysis code

NASA Technical Reports Server (NTRS)

Mcglathery, D. M.

1973-01-01

A preliminary space shuttle mission design and analysis tool is reported emphasizing versatility, flexibility, and user interaction through the use of a relatively small computer (IBM-7044). The Space Shuttle Rendezvous, Radiation and Reentry Analysis Code is used to perform mission and space radiation environmental analyses for four typical space shuttle missions. Included also is a version of the proposed Apollo/Soyuz rendezvous and docking test mission. Tangential steering circle to circle low-thrust tug orbit raising and the effects of the trapped radiation environment on trajectory shaping due to solar electric power losses are also features of this mission analysis code. The computational results include a parametric study on single impulse versus double impulse deorbiting for relatively low space shuttle orbits as well as some definitive data on the magnetically trapped protons and electrons encountered on a particular mission.

Determination of the viscous acoustic field for liquid drop positioning/forcing in an acoustic levitation chamber in microgravity

NASA Technical Reports Server (NTRS)

Lyell, Margaret J.

1992-01-01

The development of acoustic levitation systems has provided a technology with which to undertake droplet studies as well as do containerless processing experiments in a microgravity environment. Acoustic levitation chambers utilize radiation pressure forces to position/manipulate the drop. Oscillations can be induced via frequency modulation of the acoustic wave, with the modulated acoustic radiation vector acting as the driving force. To account for tangential as well as radial forcing, it is necessary that the viscous effects be included in the acoustic field. The method of composite expansions is employed in the determination of the acoustic field with viscous effects.

Wide-angle ITER-prototype tangential infrared and visible viewing system for DIII-D.

PubMed

Lasnier, C J; Allen, S L; Ellis, R E; Fenstermacher, M E; McLean, A G; Meyer, W H; Morris, K; Seppala, L G; Crabtree, K; Van Zeeland, M A

2014-11-01

An imaging system with a wide-angle tangential view of the full poloidal cross-section of the tokamak in simultaneous infrared and visible light has been installed on DIII-D. The optical train includes three polished stainless steel mirrors in vacuum, which view the tokamak through an aperture in the first mirror, similar to the design concept proposed for ITER. A dichroic beam splitter outside the vacuum separates visible and infrared (IR) light. Spatial calibration is accomplished by warping a CAD-rendered image to align with landmarks in a data image. The IR camera provides scrape-off layer heat flux profile deposition features in diverted and inner-wall-limited plasmas, such as heat flux reduction in pumped radiative divertor shots. Demonstration of the system to date includes observation of fast-ion losses to the outer wall during neutral beam injection, and shows reduced peak wall heat loading with disruption mitigation by injection of a massive gas puff.

Two Sources of Nonisotropic Radiation From Underground Explosions in Granite

DOE PAGES

Vorobiev, O. Yu.

2017-10-23

Significant tangential ground motion observed during underground explosions makes it difficult to distinguish them from natural earthquakes. Such motion can be generated by the source geometry and emplacement conditions, by the heterogeneous nature of the rock mass (mechanical properties may vary in space due to the presence of cracks, joints, faults, and various geologic layers) and also by the nonuniform in situ stress state. The last mechanism is increasingly important with depth when the difference in main principal stresses becomes significant. This paper is focused on the role of material strength of the rock mass in generation of nonradial motionmore » during explosions in prestressed media. Numerical modeling of underground chemical explosions in granite at various depths has been conducted to compare two possible mechanisms of shear wave generation. The first, caused by rock mass anisotropy, is important at shallow depth. The second is related to elastic-plastic relaxation around the cavity created by the explosion. As a result, tangential motions for these two mechanisms have different signatures.« less

Two Sources of Nonisotropic Radiation From Underground Explosions in Granite

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vorobiev, O. Yu.

Significant tangential ground motion observed during underground explosions makes it difficult to distinguish them from natural earthquakes. Such motion can be generated by the source geometry and emplacement conditions, by the heterogeneous nature of the rock mass (mechanical properties may vary in space due to the presence of cracks, joints, faults, and various geologic layers) and also by the nonuniform in situ stress state. The last mechanism is increasingly important with depth when the difference in main principal stresses becomes significant. This paper is focused on the role of material strength of the rock mass in generation of nonradial motionmore » during explosions in prestressed media. Numerical modeling of underground chemical explosions in granite at various depths has been conducted to compare two possible mechanisms of shear wave generation. The first, caused by rock mass anisotropy, is important at shallow depth. The second is related to elastic-plastic relaxation around the cavity created by the explosion. As a result, tangential motions for these two mechanisms have different signatures.« less

Wide-angle ITER-prototype tangential infrared and visible viewing system for DIII-D

DOE PAGES

Lasnier, Charles J.; Allen, Steve L.; Ellis, Ronald E.; ...

2014-08-26

An imaging system with a wide-angle tangential view of the full poloidal cross-section of the tokamak in simultaneous infrared and visible light has been installed on DIII-D. The optical train includes three polished stainless steel mirrors in vacuum, which view the tokamak through an aperture in the first mirror, similar to the design concept proposed for ITER. A dichroic beam splitter outside the vacuum separates visible and infrared (IR) light. Spatial calibration is accomplished by warping a CAD-rendered image to align with landmarks in a data image. The IR camera provides scrape-off layer heat flux profile deposition features in divertedmore » and inner-wall-limited plasmas, such as heat flux reduction in pumped radiative divertor shots. As a result, demonstration of the system to date includes observation of fast-ion losses to the outer wall during neutral beam injection, and shows reduced peak wall heat loading with disruption mitigation by injection of a massive gas puff.« less

Electric-field distribution near rectangular microstrip radiators for hyperthermia heating: theory versus experiment in water.

PubMed

Underwood, H R; Peterson, A F; Magin, R L

1992-02-01

A rectangular microstrip antenna radiator is investigated for its near-zone radiation characteristics in water. Calculations of a cavity model theory are compared with the electric-field measurements of a miniature nonperturbing diode-dipole E-field probe whose 3 mm tip was positioned by an automatic three-axis scanning system. These comparisons have implications for the use of microstrip antennas in a multielement microwave hyperthermia applicator. Half-wavelength rectangular microstrip patches were designed to radiate in water at 915 MHz. Both low (epsilon r = 10) and high (epsilon r = 85) dielectric constant substrates were tested. Normal and tangential components of the near-zone radiated electric field were discriminated by appropriate orientation of the E-field probe. Low normal to transverse electric-field ratios at 3.0 cm depth indicate that the radiators may be useful for hyperthermia heating with an intervening water bolus. Electric-field pattern addition from a three-element linear array of these elements in water indicates that phase and amplitude adjustment can achieve some limited control over the distribution of radiated power.

Microsphere coated substrate containing reactive aldehyde groups

NASA Technical Reports Server (NTRS)

Yen, Richard C. K. (Inventor); Rembaum, Alan (Inventor)

1984-01-01

A synthetic organic resin is coated with a continuous layer of contiguous, tangential, individual microspheres having a uniform diameter preferably between 100 Angstroms and 2000 Angstroms. The microspheres are an addition polymerized polymer of an unsaturated aldehyde containing 4 to 20 carbon atoms and are covalently bonded to the substrate by means of high energy radiation grafting. The microspheres contain reactive aldehyde groups and can form conjugates with proteins such as enzymes or other aldehyde reactive materials.

Comparison of PDR brachytherapy and external beam radiation therapy in the case of breast cancer

NASA Astrophysics Data System (ADS)

Teymournia, L.; Berger, D.; Kauer-Dorner, D.; Poljanc, K.; Seitz, W.; Aiginger, H.; Kirisits, C.

2009-04-01

Pulsed dose rate brachytherapy (PDR) was compared to external beam radiation therapy (EBRT) in the case of breast cancer. The benefits were figured out by evaluation of dosimetric parameters and calculating the normal tissue complication probability (NTCP). PDR plans were set up for five randomly chosen left-sided breast cancer patients delivering a total dose of 50.4 Gy to the target (dose rate 0.8 Gy h-1). For EBRT five left-sided breast cancer patients were planned using 3D-conformal tangential photon beams with a prescribed total dose of 50 Gy (2 Gy/fraction) to the total breast volume. For plan ranking and NTCP calculation the physical dose was first converted into the biologically effective dose (BED) and then into the normalized total dose (NTD) using the linear quadratic model with an α/β ratio of 3 Gy. In PDR the relative effectiveness (RE) was calculated for each dose bin of the differential dose volume histogram to get the BED. NTCPs were calculated for the ipsilateral lung and the heart as contoured on CT slices based on the Lyman model and the Kutcher reduction scheme. Dosimetric parameters as Vth (percentage of the total volume exceeding a threshold dose) and Jackson's fdam (fraction of the organ damaged) were also used to figure out the benefits. The comparison of calculated NTCPs in PDR and EBRT showed no difference between these two modalities. All values were below 0.01%. fdam derived from EBRT was always higher (mean value 8.95% versus 1.21% for the lung). The mean V10 and V20 of the lung related to BED were 6.32% and 1.72% for PDR versus 11.72% and 9.59% for EBRT. When using dosimetric parameters as Vth and fdam, PDR was mostly superior to EBRT in respect of sparing normal tissues. NTCP calculation as a single method of modality ranking showed a lack of information, especially when normal tissue was exposed to low radiation doses.

Properties of Tangential and Cyclic Polygons: An Application of Circulant Matrices

ERIC Educational Resources Information Center

Leung, Allen; Lopez-Real, Francis

2003-01-01

In this paper, the properties of tangential and cyclic polygons proposed by Lopez-Real are proved rigorously using the theory of circulant matrices. In particular, the concepts of slippable tangential polygons and conformable cyclic polygons are defined. It is shown that an n-sided tangential (or cyclic) polygon P[subscript n] with n even is…

Preliminary studies of radiation coupling between remote soft X-ray laser amplifiers

NASA Astrophysics Data System (ADS)

Cairns, G.; Lewis, C. L. S.; Macphee, A. G.; Neely, D.; Holden, M.; Krishnan, J.; Tallents, G. J.; Key, M. H.; Norreys, P. N.; Smith, C. G.; Zhang, J.; Holden, P. B.; Pert, G. J.; Plowes, J.; Ramsden, S. A.

1994-01-01

Coupling of a soft X-ray laser beam with a relaying concave mirror in a sequentially pumped amplifier geometry using the Ne-like Ge system has been studied experimentally. Preliminary observations indicate an increase in the spatial coherence of the amplified relayed beam. In addition, near-field imaging of one of the amplifier plasmas shows a double-lobed intensity pattern of the emergent beam indicating refractive guiding of the amplified beam with components both normal and tangential to the target surface.

Comparison of histologic margin status in low-grade cutaneous and subcutaneous canine mast cell tumours examined by radial and tangential sections.

PubMed

Dores, C B; Milovancev, M; Russell, D S

2018-03-01

Radial sections are widely used to estimate adequacy of excision in canine cutaneous mast cell tumours (MCTs); however, this sectioning technique estimates only a small fraction of total margin circumference. This study aimed to compare histologic margin status in grade II/low grade MCTs sectioned using both radial and tangential sectioning techniques. A total of 43 circumferential margins were evaluated from 21 different tumours. Margins were first sectioned radially, followed by tangential sections. Tissues were examined by routine histopathology. Tangential margin status differed in 10 of 43 (23.3%) margins compared with their initial status on radial section. Of 39 margins, 9 (23.1%) categorized as histologic tumour-free margin (HTFM) >0 mm were positive on tangential sectioning. Tangential sections detected a significantly higher proportion of positive margins relative to radial sections (exact 2-tailed P-value = .0215). The HTFM was significantly longer in negative tangential margins than positive tangential margins (mean 10.1 vs 3.2 mm; P = .0008). A receiver operating characteristic curve comparing HTFM and tangentially negative margins found an area under the curve of 0.83 (95% confidence interval: 0.71-0.96). Although correct classification peaked at the sixth cut-point of HTFM ≥1 mm, radial sections still incorrectly classified 50% of margins as lacking tumour cells. Radial sections had 100% specificity for predicting negative tangential margins at a cut-point of 10.9 mm. These data indicate that for low grade MCTs, HTFMs >0 mm should not be considered completely excised, particularly when HTFM is <10.9 mm. This will inform future studies that use HTFM and overall excisional status as dependent variables in multivariable prognostic models. © 2017 John Wiley & Sons Ltd.

Conserved pattern of tangential neuronal migration during forebrain development.

PubMed

Métin, Christine; Alvarez, Chantal; Moudoux, David; Vitalis, Tania; Pieau, Claude; Molnár, Zoltán

2007-08-01

Origin, timing and direction of neuronal migration during brain development determine the distinct organization of adult structures. Changes in these processes might have driven the evolution of the forebrain in vertebrates. GABAergic neurons originate from the ganglionic eminence in mammals and migrate tangentially to the cortex. We are interested in differences and similarities in tangential migration patterns across corresponding telencephalic territories in mammals and reptiles. Using morphological criteria and expression patterns of Darpp-32, Tbr1, Nkx2.1 and Pax6 genes, we show in slice cultures of turtle embryos that early cohorts of tangentially migrating cells are released from the medial ganglionic eminence between stages 14 and 18. Additional populations migrate tangentially from the dorsal subpallium. Large cohorts of tangentially migrating neurons originate ventral to the dorsal ventricular ridge at stage 14 and from the lateral ganglionic eminence from stage 15. Release of GABAergic cells from these regions was investigated further in explant cultures. Tangential migration in turtle proceeds in a fashion similar to mammals. In chimeric slice culture and in ovo graft experiments, the tangentially migrating cells behaved according to the host environment - turtle cells responded to the available cues in mouse slices and mouse cells assumed characteristic migratory routes in turtle brains, indicating highly conserved embryonic signals between these distant species. Our study contributes to the evaluation of theories on the origin of the dorsal cortex and indicates that tangential migration is universal in mammals and sauropsids.

Impact of chemical reaction in fully developed radiated mixed convective flow between two rotating disk

NASA Astrophysics Data System (ADS)

Hayat, T.; Khan, M. Waleed Ahmed; Khan, M. Ijaz; Waqas, M.; Alsaedi, A.

2018-06-01

Flow of magnetohydrodynamic (MHD) viscous fluid between two rotating disks is modeled. Angular velocities of two disks are different. Flow is investigated for nonlinear mixed convection. Heat transfer is analyzed for nonlinear thermal radiation and heat generation/absorption. Chemical reaction is also implemented. Convective conditions of heat and mass transfer are studied. Transformations used lead to reduction of PDEs into the ODEs. The impacts of important physical variables like Prandtl number, Reynold number, Hartman number, mixed convection parameter, chemical reaction and Schmidt number on velocities, temperature and concentration are elaborated. In addition velocity and temperature gradients are physically interpreted. Our obtained results indicate that radial, axial and tangential velocities decrease for higher estimation of Hartman number.

Transverse circular-polarized Bessel beam generation by inward cylindrical aperture distribution.

PubMed

Pavone, S C; Ettorre, M; Casaletti, M; Albani, M

2016-05-16

In this paper the focusing capability of a radiating aperture implementing an inward cylindrical traveling wave tangential electric field distribution directed along a fixed polarization unit vector is investigated. In particular, it is shown that such an aperture distribution generates a non-diffractive Bessel beam whose transverse component (with respect to the normal of the radiating aperture) of the electric field takes the form of a zero-th order Bessel function. As a practical implementation of the theoretical analysis, a circular-polarized Bessel beam launcher, made by a radial parallel plate waveguide loaded with several slot pairs, arranged on a spiral pattern, is designed and optimized. The proposed launcher performance agrees with the theoretical model and exhibits an excellent polarization purity.

Ascl1 promotes tangential migration and confines migratory routes by induction of Ephb2 in the telencephalon

PubMed Central

Liu, Yuan-Hsuan; Tsai, Jin-Wu; Chen, Jia-Long; Yang, Wan-Shan; Chang, Pei-Ching; Cheng, Pei-Lin; Turner, David L.; Yanagawa, Yuchio; Wang, Tsu-Wei; Yu, Jenn-Yah

2017-01-01

During development, cortical interneurons generated from the ventral telencephalon migrate tangentially into the dorsal telencephalon. Although Achaete-scute family bHLH transcription factor 1 (Ascl1) plays important roles in the developing telencephalon, whether Ascl1 regulates tangential migration remains unclear. Here, we found that Ascl1 promoted tangential migration along the ventricular zone/subventricular zone (VZ/SVZ) and intermediate zone (IZ) of the dorsal telencephalon. Distal-less homeobox 2 (Dlx2) acted downstream of Ascl1 in promoting tangential migration along the VZ/SVZ but not IZ. We further identified Eph receptor B2 (Ephb2) as a direct target of Ascl1. Knockdown of EphB2 disrupted the separation of the VZ/SVZ and IZ migratory routes. Ephrin-A5, a ligand of EphB2, was sufficient to repel both Ascl1-expressing cells in vitro and tangentially migrating cortical interneurons in vivo. Together, our results demonstrate that Ascl1 induces expression of Dlx2 and Ephb2 to maintain distinct tangential migratory routes in the dorsal telencephalon. PMID:28276447

Numerical simulation and experiment on split tungsten carbide cylinder of high pressure apparatus

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yang, Yunfei; Li, Mingzhe, E-mail: limz@jlu.edu.cn; Wang, Bolong

2015-12-15

A new high pressure device with a split cylinder was investigated on the basis of the belt-type apparatus. The belt-type die is subjected to excessive tangential tensile stress and the tungsten carbide cylinder is easily damaged in the running process. Taking into account the operating conditions and material properties of the tungsten carbide cylinder, it is divided into 6 blocks to eliminate the tangential tensile stress. We studied two forms of the split type: radial split and tangential split. Simulation results indicate that the split cylinder has more uniform stress distribution and smaller equivalent stress compared with the belt-type cylinder.more » The inner wall of the tangential split cylinder is in the situation that compressive stress is distributed in the axial, radial, and tangential directions. It is similar to the condition of hydrostatic pressure, and it is the best condition for tungsten carbide materials. The experimental results also verify that the tangential split die can bear the highest chamber pressure. Therefore, the tangential split structure can increase the pressure bearing capacity significantly.« less

Computer prediction of large reflector antenna radiation properties

NASA Technical Reports Server (NTRS)

Botula, A.

1980-01-01

A FORTRAN program for calculating reflector antenna radiation patterns was rewritten and extended to include reflectors composed of a number of panels. These individual panels must be analytic surfaces. The theoretical foundation for the program is as follows: Geometrical optics techniques are used to trace rays from a feed antenna to the reflector surface and back to a mathematical plane just in front of the reflector. The resulting tangential electric field distribution, assumed to be the only source of forward radiation, is integrated numerically to calculate the radiation pattern for a desired set of angles. When the reflector is composed of more than one panel, each panel is treated as a separated antenna, the ray-tracing procedure and integration being repeated for each panel. The results of the individual aperture plane integrations are stored and summed to yield the relative electric field strength over the angles of interest. An example and several test cases are included to demonstrate the use of the program and verify the new method of computation.

Allogeneic cell therapy bioprocess economics and optimization: downstream processing decisions.

PubMed

Hassan, Sally; Simaria, Ana S; Varadaraju, Hemanthram; Gupta, Siddharth; Warren, Kim; Farid, Suzanne S

2015-01-01

To develop a decisional tool to identify the most cost effective process flowsheets for allogeneic cell therapies across a range of production scales. A bioprocess economics and optimization tool was built to assess competing cell expansion and downstream processing (DSP) technologies. Tangential flow filtration was generally more cost-effective for the lower cells/lot achieved in planar technologies and fluidized bed centrifugation became the only feasible option for handling large bioreactor outputs. DSP bottlenecks were observed at large commercial lot sizes requiring multiple large bioreactors. The DSP contribution to the cost of goods/dose ranged between 20-55%, and 50-80% for planar and bioreactor flowsheets, respectively. This analysis can facilitate early decision-making during process development.

Observation of radiative surface plasmons in metal-oxide-metal tunnel junctions

NASA Technical Reports Server (NTRS)

Donohue, J. F.; Yang, E. Y.

1986-01-01

A peak in the UV region of the spectrum of light emitted from metal-oxide-metal (MOM) tunnel junctions has been observed at room temperature. Both the amplitude and wavelength of the peak are sensitive to applied junction bias. The UV peak corresponds to the normal or radiative surface plasmon mode while a visible peak, also present in the present spectra and reported in past MOM literature, is due to the tangential or nonradiative mode. The radiative mode requires no surface roughness or gratings for photon coupling. The results show that it is possible to obtain radiative surface plasmon production followed by a direct decay into photons with MOM tunnel diodes. A MOM diode with a double anode structure is found to emit light associated only with the nonradiative mode. The thickness dependence of the UV peak, along with the experimental results of the double anode MOM diode and the ratio of the UV peak to visible peak, support the contention that the UV light emission is indeed due to the radiative surface plasmon.

Survival times for canine intranasal sarcomas treated with radiation therapy: 86 cases (1996-2011).

PubMed

Sones, Evan; Smith, Annette; Schleis, Stephanie; Brawner, William; Almond, Gregory; Taylor, Kathryn; Haney, Siobhan; Wypij, Jackie; Keyerleber, Michele; Arthur, Jennifer; Hamilton, Terrance; Lawrence, Jessica; Gieger, Tracy; Sellon, Rance; Wright, Zack

2013-01-01

Sarcomas comprise approximately one-third of canine intranasal tumors, however few veterinary studies have described survival times of dogs with histologic subtypes of sarcomas separately from other intranasal tumors. One objective of this study was to describe median survival times for dogs treated with radiation therapy for intranasal sarcomas. A second objective was to compare survival times for dogs treated with three radiation therapy protocols: daily-fractionated radiation therapy; Monday, Wednesday, and Friday fractionated radiation therapy; and palliative radiation therapy. Medical records were retrospectively reviewed for dogs that had been treated with radiation therapy for confirmed intranasal sarcoma. A total of 86 dogs met inclusion criteria. Overall median survival time for included dogs was 444 days. Median survival time for dogs with chondrosarcoma (n = 42) was 463 days, fibrosarcoma (n = 12) 379 days, osteosarcoma (n = 6) 624 days, and undifferentiated sarcoma (n = 22) 344 days. Dogs treated with daily-fractionated radiation therapy protocols; Monday, Wednesday and Friday fractionated radiation therapy protocols; and palliative radiation therapy protocols had median survival times of 641, 347, and 305 days, respectively. A significant difference in survival time was found for dogs receiving curative intent radiation therapy vs. palliative radiation therapy (P = 0.032). A significant difference in survival time was also found for dogs receiving daily-fractionated radiation therapy vs. Monday, Wednesday and Friday fractionated radiation therapy (P = 0.0134). Findings from this study support the use of curative intent radiation therapy for dogs with intranasal sarcoma. Future prospective, randomized trials are needed for confirmation of treatment benefits. © 2012 Veterinary Radiology & Ultrasound.

42 CFR 410.35 - X-ray therapy and other radiation therapy services: Scope.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 42 Public Health 2 2012-10-01 2012-10-01 false X-ray therapy and other radiation therapy services... Other Health Services § 410.35 X-ray therapy and other radiation therapy services: Scope. Medicare Part B pays for X-ray therapy and other radiation therapy services, including radium therapy and...

42 CFR 410.35 - X-ray therapy and other radiation therapy services: Scope.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 42 Public Health 2 2011-10-01 2011-10-01 false X-ray therapy and other radiation therapy services... Other Health Services § 410.35 X-ray therapy and other radiation therapy services: Scope. Medicare Part B pays for X-ray therapy and other radiation therapy services, including radium therapy and...

42 CFR 410.35 - X-ray therapy and other radiation therapy services: Scope.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 42 Public Health 2 2013-10-01 2013-10-01 false X-ray therapy and other radiation therapy services... Other Health Services § 410.35 X-ray therapy and other radiation therapy services: Scope. Medicare Part B pays for X-ray therapy and other radiation therapy services, including radium therapy and...

42 CFR 410.35 - X-ray therapy and other radiation therapy services: Scope.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 42 Public Health 2 2014-10-01 2014-10-01 false X-ray therapy and other radiation therapy services... Other Health Services § 410.35 X-ray therapy and other radiation therapy services: Scope. Medicare Part B pays for X-ray therapy and other radiation therapy services, including radium therapy and...

42 CFR 410.35 - X-ray therapy and other radiation therapy services: Scope.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 42 Public Health 2 2010-10-01 2010-10-01 false X-ray therapy and other radiation therapy services... Other Health Services § 410.35 X-ray therapy and other radiation therapy services: Scope. Medicare Part B pays for X-ray therapy and other radiation therapy services, including radium therapy and...

Purged window apparatus utilizing heated purge gas

DOEpatents

Ballard, Evan O.

1984-01-01

A purged window apparatus utilizing tangentially injected heated purge gases in the vicinity of electromagnetic radiation transmitting windows, and a tapered external mounting tube to accelerate these gases to provide a vortex flow on the window surface and a turbulent flow throughout the mounting tube. Use of this apparatus prevents backstreaming of gases under investigation which are flowing past the mouth of the mounting tube which would otherwise deposit on the windows. Lengthy spectroscopic investigations and analyses can thereby be performed without the necessity of interrupting the procedures in order to clean or replace contaminated windows.

21 CFR 892.5050 - Medical charged-particle radiation therapy system.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Medical charged-particle radiation therapy system...-particle radiation therapy system. (a) Identification. A medical charged-particle radiation therapy system...) intended for use in radiation therapy. This generic type of device may include signal analysis and display...

Experimental validation of alternate integral-formulation method for predicting acoustic radiation based on particle velocity measurements.

PubMed

Ni, Zhi; Wu, Sean F

2010-09-01

This paper presents experimental validation of an alternate integral-formulation method (AIM) for predicting acoustic radiation from an arbitrary structure based on the particle velocities specified on a hypothetical surface enclosing the target source. Both the normal and tangential components of the particle velocity on this hypothetical surface are measured and taken as the input to AIM codes to predict the acoustic pressures in both exterior and interior regions. The results obtained are compared with the benchmark values measured by microphones at the same locations. To gain some insight into practical applications of AIM, laser Doppler anemometer (LDA) and double hotwire sensor (DHS) are used as measurement devices to collect the particle velocities in the air. Measurement limitations of using LDA and DHS are discussed.

Effects of magnetic drift tangential to magnetic surfaces on neoclassical transport in non-axisymmetric plasmas

DOE Office of Scientific and Technical Information (OSTI.GOV)

Matsuoka, Seikichi, E-mail: matsuoka@rist.or.jp; Satake, Shinsuke; Kanno, Ryutaro

2015-07-15

In evaluating neoclassical transport by radially local simulations, the magnetic drift tangential to a flux surface is usually ignored in order to keep the phase-space volume conservation. In this paper, effect of the tangential magnetic drift on the local neoclassical transport is investigated. To retain the effect of the tangential magnetic drift in the local treatment of neoclassical transport, a new local formulation for the drift kinetic simulation is developed. The compressibility of the phase-space volume caused by the tangential magnetic drift is regarded as a source term for the drift kinetic equation, which is solved by using a two-weightmore » δf Monte Carlo method for non-Hamiltonian system [G. Hu and J. A. Krommes, Phys. Plasmas 1, 863 (1994)]. It is demonstrated that the effect of the drift is negligible for the neoclassical transport in tokamaks. In non-axisymmetric systems, however, the tangential magnetic drift substantially changes the dependence of the neoclassical transport on the radial electric field E{sub r}. The peaked behavior of the neoclassical radial fluxes around E{sub r }={sub  }0 observed in conventional local neoclassical transport simulations is removed by taking the tangential magnetic drift into account.« less

Applications of Machine Learning for Radiation Therapy.

PubMed

Arimura, Hidetaka; Nakamoto, Takahiro

2016-01-01

Radiation therapy has been highly advanced as image guided radiation therapy (IGRT) by making advantage of image engineering technologies. Recently, novel frameworks based on image engineering technologies as well as machine learning technologies have been studied for sophisticating the radiation therapy. In this review paper, the author introduces several researches of applications of machine learning for radiation therapy. For examples, a method to determine the threshold values for standardized uptake value (SUV) for estimation of gross tumor volume (GTV) in positron emission tomography (PET) images, an approach to estimate the multileaf collimator (MLC) position errors between treatment plans and radiation delivery time, and prediction frameworks for esophageal stenosis and radiation pneumonitis risk after radiation therapy are described. Finally, the author introduces seven issues that one should consider when applying machine learning models to radiation therapy.

Effects of Tangential Edge Constraints on the Postbuckling Behavior of Flat and Curved Panels Subjected to Thermal and Mechanical Loads

NASA Technical Reports Server (NTRS)

Lin, W.; Librescu, L.; Nemeth, M. P.; Starnes, J. H. , Jr.

1994-01-01

A parametric study of the effects of tangential edge constraints on the postbuckling response of flat and shallow curved panels subjected to thermal and mechanical loads is presented. The mechanical loads investigated are uniform compressive edge loads and transverse lateral pressure. The temperature fields considered are associated with spatially nonuniform heating over the panels, and a linear through-the-thickness temperature gradient. The structural model is based on a higher-order transverse-shear-deformation theory of shallow shells that incorporates the effects of geometric nonlinearities, initial geometric imperfections, and tangential edge motion constraints. Results are presented for three-layer sandwich panels made from transversely isotropic materials. Simply supported panels are considered in which the tangential motion of the unloaded edges is either unrestrained, partially restrained, or fully restrained. These results focus on the effects of the tangential edge restraint on the postbuckling response. The results of this study indicate that tangentially restraining the edges of a curved panel can make the panel insensitive to initial geometric imperfections in some cases.

Pirfenidone enhances the efficacy of combined radiation and sunitinib therapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Choi, Seo-Hyun; Nam, Jae-Kyung; Jang, Junho

Radiotherapy is a widely used treatment for many tumors. Combination therapy using anti-angiogenic agents and radiation has shown promise; however, these combined therapies are reported to have many limitations in clinical trials. Here, we show that radiation transformed tumor endothelial cells (ECs) to fibroblasts, resulting in reduced vascular endothelial growth factor (VEGF) response and increased Snail1, Twist1, Type I collagen, and transforming growth factor (TGF)-β release. Irradiation of radioresistant Lewis lung carcinoma (LLC) tumors greater than 250 mm{sup 3} increased collagen levels, particularly in large tumor vessels. Furthermore, concomitant sunitinib therapy did not show a significant difference in tumor inhibition versusmore » radiation alone. Thus, we evaluated multimodal therapy that combined pirfenidone, an inhibitor of TGF-induced collagen production, with radiation and sunitinib treatment. This trimodal therapy significantly reduced tumor growth, as compared to radiation alone. Immunohistochemical analysis revealed that radiation-induced collagen deposition and tumor microvessel density were significantly reduced with trimodal therapy, as compared to radiation alone. These data suggest that combined therapy using pirfenidone may modulate the radiation-altered tumor microenvironment, thereby enhancing the efficacy of radiation therapy and concurrent chemotherapy. - Highlights: • Radiation changes tumor endothelial cells to fibroblasts. • Radio-resistant tumors contain collagen deposits, especially in tumor vessels. • Pirfenidone enhances the efficacy of combined radiation and sunitinib therapy. • Pirfenidone reduces radiation-induced collagen deposits in tumors.« less

Development of Radiated Power Diagnostics for NSTX-U

NASA Astrophysics Data System (ADS)

Reinke, Matthew; van Eden, G. G.; Lovell, Jack; Peterson, Byron; Gray, Travis; Chandra, Rian; Stratton, Brent; Ellis, Robert; NSTX-U Team

2016-10-01

New tools to measure radiated power in NSTX-U are under development to support a range of core and boundary physics research. Multiple resistive bolometer pinhole cameras are being built and calibrated to support FY17 operations, all utilizing standard Au-foil sensors from IPT-Albrecht. The radiation in the lower divertor will be measured using two, 8 channel arrays viewing both vertically and radially to enable estimates of the 2D radiation structure. The core radiation will be measured using a 24 channel array viewing tangentially near the midplane, observing the full cross-section from the inner to outer limiter. This enables characterization of the centrifugally-driven in/out radiation asymmetry expected from mid-Z and high-Z impurities in highly rotating NSTX-U plasmas. All sensors utilize novel FPGA-based BOLO8BLF analyzers from D-tAcq Solutions. Resistive bolometer measurements are complemented by an InfraRed Video Bolometer (IRVB) which measures the temperature change of radiation absorber using an IR camera. A prototype IRVB system viewing the lower divertor was installed on NSTX-U for FY16 operations. Initial results from the plasma and benchtop testing are used to demonstrate the relative advantages between IRVB and resistive bolometers. Supported in Part by DE-AC05-00OR22725 & DE-AC02-09CH11466.

Aerosols optical properties in Titan's detached haze layer before the equinox

NASA Astrophysics Data System (ADS)

Seignovert, Benoît; Rannou, Pascal; Lavvas, Panayotis; Cours, Thibaud; West, Robert A.

2017-08-01

UV observations with Cassini ISS Narrow Angle Camera of Titan's detached haze is an excellent tool to probe its aerosols content without being affected by the gas or the multiple scattering. Unfortunately, its low extent in altitude requires a high resolution calibration and limits the number of images available in the Cassini dataset. However, we show that it is possible to extract on each profile the local maximum of intensity of this layer and confirm its stability at 500 ± 8 km during the 2005-2007 period for all latitudes lower than 45°N. Using the fractal aggregate scattering model of Tomasko et al. (2008) and a single scattering radiative transfer model, it is possible to derive the optical properties required to explain the observations made at different phase angles. Our results indicates that the aerosols have at least ten monomers of 60 nm radius, while the typical tangential column number density is about 2 · 1010 agg m-2. Moreover, we demonstrate that these properties are constant within the error bars in the southern hemisphere of Titan over the observed time period. In the northern hemisphere, the size of the aerosols tends to decrease relatively to the southern hemisphere and is associated with a higher tangential opacity. However, the lower number of observations available in this region due to the orbital constraints is a limiting factor in the accuracy of these results. Assuming a fixed homogeneous content we notice that the tangential opacity can fluctuate up to a factor 3 among the observations at the equator. These variations could be linked with short scale temporal and/or longitudinal events changing the local density of the layer.

Assessing Adverse Events of Postprostatectomy Radiation Therapy for Prostate Cancer: Evaluation of Outcomes in the Regione Emilia-Romagna, Italy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Showalter, Timothy N., E-mail: tns3b@virginia.edu; Hegarty, Sarah E.; Division of Biostatistics, Department of Pharmacology and Experimental Therapeutics, Sidney Kimmel Medical College at Thomas Jefferson University, Philadelphia, Pennsylvania

Purpose: Although the likelihood of radiation-related adverse events influences treatment decisions regarding radiation therapy after prostatectomy for eligible patients, the data available to inform decisions are limited. This study was designed to evaluate the genitourinary, gastrointestinal, and sexual adverse events associated with postprostatectomy radiation therapy and to assess the influence of radiation timing on the risk of adverse events. Methods: The Regione Emilia-Romagna Italian Longitudinal Health Care Utilization Database was queried to identify a cohort of men who received radical prostatectomy for prostate cancer during 2003 to 2009, including patients who received postprostatectomy radiation therapy. Patients with prior radiation therapymore » were excluded. Outcome measures were genitourinary, gastrointestinal, and sexual adverse events after prostatectomy. Rates of adverse events were compared between the cohorts who did and did not receive postoperative radiation therapy. Multivariable Cox proportional hazards models were developed for each class of adverse events, including models with radiation therapy as a time-varying covariate. Results: A total of 9876 men were included in the analyses: 2176 (22%) who received radiation therapy and 7700 (78%) treated with prostatectomy alone. In multivariable Cox proportional hazards models, the additional exposure to radiation therapy after prostatectomy was associated with increased rates of gastrointestinal (rate ratio [RR] 1.81; 95% confidence interval [CI] 1.44-2.27; P<.001) and urinary nonincontinence events (RR 1.83; 95% CI 1.83-2.80; P<.001) but not urinary incontinence events or erectile dysfunction. The addition of the time from prostatectomy to radiation therapy interaction term was not significant for any of the adverse event outcomes (P>.1 for all outcomes). Conclusion: Radiation therapy after prostatectomy is associated with an increase in gastrointestinal and genitourinary adverse events. However, the timing of radiation therapy did not influence the risk of radiation therapy–associated adverse events in this cohort, which contradicts the commonly held clinical tenet that delaying radiation therapy reduces the risk of adverse events.« less

Maser emission from planetary and stellar magnetospheres

NASA Astrophysics Data System (ADS)

Speirs, David

2012-07-01

A variety of astrophysical radio emissions have been identified to date in association with non-uniform magnetic fields and charged particle streams. From terrestrial auroral kilometric radiation (AKR) to observations of auroral radio emission from the flare star UV Ceti and CU Virginis, there are numerous examples of this intense, highly polarised magnetospheric radio signature [1][2]. Characterised by discrete spectral components at ~300kHz in the terrestrial auroral case, the radiation is clearly non-thermal and there is a strong belief that such emissions are generated by an electron cyclotron maser instability [1]. Previous work has focussed on a loss cone generation mechanism and cavity ducting model for radiation beaming, however recent theory and simulations suggest an alternative model comprising emission driven by an electron horseshoe distribution [1]. Such distributions are formed when particles descend into the increasing magnetic field of planetary / stellar auroral magnetospheres, where conservation of the magnetic moment results in conversion of axial momentum into rotational momentum. Theory has demonstrated that such distributions are highly unstable to cyclotron emission in the X-mode [3], and that these emissions when propagating tangential to the plasma cavity boundary may refract upwards due to plasma density inhomogeneity [4]. Scaled experiments have been conducted at the University of Strathclyde to study the emission process under controlled laboratory conditions [5]. In addition, numerical models have simulated the emission mechanism in the presence of a background plasma and in the absence of radiation boundaries [6]. Here we present the results of beam-plasma simulations that confirm the radiation model for tangential growth and upward refraction [4] and agree with recent Jodrell Bank observations of pulsed, narrowly beamed radio emission from the oblique rotator star CU Virginis [2]. [1] R. Bingham and R. A. Cairns, Phys. Plasmas, 7, 3089 (2000). [2] B.J. Kellett, V. Graffagnino, R. Bingham et al., ArXiv Astrophysics, 0701214 (2007). [3] R.A. Cairns, I. Vorgul, R. Bingham et al., Phys. Plasmas 18, 022902 (2011). [4] J.D. Menietti, R.L. Mutel, I.W. Christopher et al., J. Geophys. Res., 116, A12219 (2011). [5] S.L. McConville, M.E. Koepke, K.M. Gillespie et al., Plasma Phys. Control. Fusion, 53, 124020 (2011). [6] D.C. Speirs, K. Ronald, S.L. McConville, Phys. Plasmas, 17, 056501 (2010).

Analysis of Tangential Slot Blowing on F/A-18 Isolated Forebody

NASA Technical Reports Server (NTRS)

Gee, Ken; Rizk, Yehia M.; Schiff, Lewis B.

1995-01-01

The generation of significant side forces and yawing moments on an F/A-18 fuselage through tangential slot blowing is analyzed using computational fluid dynamics. The effects of freestream Mach number, jet exit conditions, jet length, and jet location are studied. The effects of over- and underblowing on force and moment production are analyzed. Non-time-accurate solutions are obtained to determine the steady-state side forces, yawing moments, and surface pressure distributions generated by tangential slot blowing. Time-accurate solutions are obtained to study the force onset time lag of tangential slot blowing. Comparison with available experimental data from full-scale wind-tunnel and subscale wind-tunnel tests are made. This computational analysis complements the experimental results and provides a detailed understanding of the effects of tangential slot blowing on the flowfield about the isolated F/A-18 forebody. Additionally, it extends the slot-blowing database to transonic maneuvering Mach numbers.

Prediction of sound radiation from different practical jet engine inlets

NASA Technical Reports Server (NTRS)

Zinn, B. T.; Meyer, W. L.

1982-01-01

The computer codes necessary for this study were developed and checked against exact solutions generated by the point source method using the NASA Lewis QCSEE inlet geometry. These computer codes were used to predict the acoustic properties of the following five inlet configurations: the NASA Langley Bellmouth, the NASA Lewis JT15D-1 Ground Test Nacelle, and three finite hyperbolic inlets of 50, 70 and 90 degrees. Thirty-five computer runs were done for the NASA Langley Bellmouth. For each of these computer runs, the reflection coefficient at the duct exit plane was calculated as was the far field radiation pattern. These results are presented in both graphical and tabular form with many of the results cross plotted so that trends in the results verses cut-off ratio (wave number) and tangential mode number may be easily identified.

SU-F-J-55: Feasibility of Supraclavicular Field Treatment by Investigating Variation of Junction Position Between Breast Tangential and Supraclavicular Fields for Deep Inspiration Breath Hold (DIBH) Left Breast Radiation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhao, H; Sarkar, V; Paxton, A

Purpose: To explore the feasibility of supraclavicular field treatment by investigating the variation of junction position between tangential and supraclavicular fields during left breast radiation using DIBH technique. Methods: Six patients with left breast cancer treated using DIBH technique were included in this study. AlignRT system was used to track patient’s breast surface. During daily treatment, when the patient’s DIBH reached preset AlignRT tolerance of ±3mm for all principle directions (vertical, longitudinal, and lateral), the remaining longitudinal offset was recorded. The average with standard-deviation and the range of daily longitudinal offset for the entire treatment course were calculated for allmore » six patients (93 fractions totally). The ranges of average ± 1σ and 2σ were calculated, and they represent longitudinal field edge error with the confidence level of 68% and 95%. Based on these longitudinal errors, dose at junction between breast tangential and supraclavicular fields with variable gap/overlap sizes was calculated as a percentage of prescription (on a representative patient treatment plan). Results: The average of longitudinal offset for all patients is 0.16±1.32mm, and the range of longitudinal offset is −2.6 to 2.6mm. The range of longitudinal field edge error at 68% confidence level is −1.48 to 1.16mm, and at 95% confidence level is −2.80 to 2.48mm. With a 5mm and 1mm gap, the junction dose could be as low as 37.5% and 84.9% of prescription dose; with a 5mm and 1mm overlap, the junction dose could be as high as 169.3% and 117.6%. Conclusion: We observed longitudinal field edge error at 95% confidence level is about ±2.5mm, and the junction dose could reach 70% hot/cold between different DIBH. However, over the entire course of treatment, the average junction variation for all patients is within 0.2mm. The results from our study shows it is potentially feasible to treat supraclavicular field with breast tangents.« less

Simulation of a tangential soft x-ray imaging system.

PubMed

Battaglia, D J; Shafer, M W; Unterberg, E A; Bell, R E; Hillis, D L; LeBlanc, B P; Maingi, R; Sabbagh, S; Stratton, B C

2010-10-01

Tangentially viewing soft x-ray (SXR) cameras are capable of detecting nonaxisymmetric plasma structures in magnetically confined plasmas. They are particularly useful for studying stationary perturbations or phenomenon that occur on a timescale faster than the plasma rotation period. Tangential SXR camera diagnostics are planned for the DIII-D and NSTX tokamaks to elucidate the static edge magnetic structure during the application of 3D perturbations. To support the design of the proposed diagnostics, a synthetic diagnostic model was developed using the CHIANTI database to estimate the SXR emission. The model is shown to be in good agreement with the measurements from an existing tangential SXR camera diagnostic on NSTX.

Purged window apparatus. [On-line spectroscopic analysis of gas flow systems

DOEpatents

Ballard, E.O.

1982-04-05

A purged window apparatus is described which utilizes tangentially injected heated purge gases in the vicinity of electromagnetic radiation transmitting windows and a tapered external mounting tube to accelerate these gases to provide a vortex flow on the window surface and a turbulent flow throughout the mounting tube thereby preventing backstreaming of flowing gases under investigation in a chamber to which a plurality of similar purged apparatus is attached with the consequent result that spectroscopic analyses can be undertaken for lengthy periods without the necessity of interrupting the flow for cleaning or replacing the windows due to contamination.

Cancer and Radiation Therapy: Current Advances and Future Directions

PubMed Central

Baskar, Rajamanickam; Lee, Kuo Ann; Yeo, Richard; Yeoh, Kheng-Wei

2012-01-01

In recent years remarkable progress has been made towards the understanding of proposed hallmarks of cancer development and treatment. However with its increasing incidence, the clinical management of cancer continues to be a challenge for the 21st century. Treatment modalities comprise of radiation therapy, surgery, chemotherapy, immunotherapy and hormonal therapy. Radiation therapy remains an important component of cancer treatment with approximately 50% of all cancer patients receiving radiation therapy during their course of illness; it contributes towards 40% of curative treatment for cancer. The main goal of radiation therapy is to deprive cancer cells of their multiplication (cell division) potential. Celebrating a century of advances since Marie Curie won her second Nobel Prize for her research into radium, 2011 has been designated the Year of Radiation therapy in the UK. Over the last 100 years, ongoing advances in the techniques of radiation treatment and progress made in understanding the biology of cancer cell responses to radiation will endeavor to increase the survival and reduce treatment side effects for cancer patients. In this review, principles, application and advances in radiation therapy with their biological end points are discussed. PMID:22408567

Cancer and radiation therapy: current advances and future directions.

PubMed

Baskar, Rajamanickam; Lee, Kuo Ann; Yeo, Richard; Yeoh, Kheng-Wei

2012-01-01

In recent years remarkable progress has been made towards the understanding of proposed hallmarks of cancer development and treatment. However with its increasing incidence, the clinical management of cancer continues to be a challenge for the 21st century. Treatment modalities comprise of radiation therapy, surgery, chemotherapy, immunotherapy and hormonal therapy. Radiation therapy remains an important component of cancer treatment with approximately 50% of all cancer patients receiving radiation therapy during their course of illness; it contributes towards 40% of curative treatment for cancer. The main goal of radiation therapy is to deprive cancer cells of their multiplication (cell division) potential. Celebrating a century of advances since Marie Curie won her second Nobel Prize for her research into radium, 2011 has been designated the Year of Radiation therapy in the UK. Over the last 100 years, ongoing advances in the techniques of radiation treatment and progress made in understanding the biology of cancer cell responses to radiation will endeavor to increase the survival and reduce treatment side effects for cancer patients. In this review, principles, application and advances in radiation therapy with their biological end points are discussed.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Barker, Christopher A., E-mail: barkerc@mskcc.org; Postow, Michael A.

Radiation therapy has long played a role in the management of melanoma. Recent advances have also demonstrated the efficacy of immunotherapy in the treatment of melanoma. Preclinical data suggest a biologic interaction between radiation therapy and immunotherapy. Several clinical studies corroborate these findings. This review will summarize the outcomes of studies reporting on patients with melanoma treated with a combination of radiation therapy and immunotherapy. Vaccine therapies often use irradiated melanoma cells, and may be enhanced by radiation therapy. The cytokines interferon-α and interleukin-2 have been combined with radiation therapy in several small studies, with some evidence suggesting increased toxicitymore » and/or efficacy. Ipilimumab, a monoclonal antibody which blocks cytotoxic T-lymphocyte antigen-4, has been combined with radiation therapy in several notable case studies and series. Finally, pilot studies of adoptive cell transfer have suggested that radiation therapy may improve the efficacy of treatment. The review will demonstrate that the combination of radiation therapy and immunotherapy has been reported in several notable case studies, series and clinical trials. These clinical results suggest interaction and the need for further study.« less

21 CFR 892.5840 - Radiation therapy simulation system.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Radiation therapy simulation system. 892.5840... (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Therapeutic Devices § 892.5840 Radiation therapy simulation system. (a) Identification. A radiation therapy simulation system is a fluoroscopic or radiographic x-ray...

21 CFR 892.5840 - Radiation therapy simulation system.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Radiation therapy simulation system. 892.5840... (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Therapeutic Devices § 892.5840 Radiation therapy simulation system. (a) Identification. A radiation therapy simulation system is a fluoroscopic or radiographic x-ray...

Stroke After Radiation Therapy for Head and Neck Cancer: What Is the Risk?

DOE Office of Scientific and Technical Information (OSTI.GOV)

Arthurs, Erin; Hanna, Timothy P.; Department of Oncology, Queen's University, Kingston, Ontario

Purpose: A retrospective population-based cohort study was conducted to determine the risk of ischemic stroke with respect to time, associated with curative radiation therapy in head and neck squamous cell carcinomas (HNSCC). Methods and Materials: On the basis of data from the Ontario Cancer Registry and regional cancer treatment centers, 14,069 patients were identified with diagnoses of squamous cell carcinoma of the oral cavity, larynx, and pharynx who were treated for cure between 1990 and 2010. Hazards of stroke and time to stroke were examined, accounting for the competing risk of death. Stroke risk factors identified through diagnostic and proceduralmore » administrative codes were adjusted for in the comparison between treatment regimens, which included surgery alone versus radiation therapy alone and surgery alone versus any exposure to radiation therapy. Results: Overall, 6% of patients experienced an ischemic stroke after treatment, with 5% experiencing a stroke after surgery, 8% after radiation therapy alone, and 6% after any exposure to radiation therapy. The cause-specific hazard ratios of ischemic stroke after radiation therapy alone and after any exposure to radiation therapy compared with surgery were 1.70 (95% confidence interval [CI]: 1.41-2.05) and 1.46 (95% CI: 1.23-1.73), respectively, after adjustment for stroke risk factors, patient factors, and disease-related factors. Conclusions: Radiation therapy was associated with an increased risk of ischemic stroke compared with surgery alone: for both radiation therapy alone and after all treatment modalities that included any radiation treatment were combined. Because of a shift toward a younger HNSCC patient population, our results speak to the need for adequate follow-up and survivorship care among patients who have been treated with radiation therapy. Advances in treatment that minimize chronic morbidity also require further evaluation.« less

Postoperative radiotherapy following mastectomy for patients with left-sided breast cancer: A comparative dosimetric study

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

21 CFR 892.5710 - Radiation therapy beam-shaping block.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Radiation therapy beam-shaping block. 892.5710... (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Therapeutic Devices § 892.5710 Radiation therapy beam-shaping block. (a) Identification. A radiation therapy beam-shaping block is a device made of a highly...

21 CFR 892.5050 - Medical charged-particle radiation therapy system.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Medical charged-particle radiation therapy system...-particle radiation therapy system. (a) Identification. A medical charged-particle radiation therapy system is a device that produces by acceleration high energy charged particles (e.g., electrons and protons...

21 CFR 892.5050 - Medical charged-particle radiation therapy system.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Medical charged-particle radiation therapy system...-particle radiation therapy system. (a) Identification. A medical charged-particle radiation therapy system is a device that produces by acceleration high energy charged particles (e.g., electrons and protons...

21 CFR 892.5050 - Medical charged-particle radiation therapy system.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Medical charged-particle radiation therapy system...-particle radiation therapy system. (a) Identification. A medical charged-particle radiation therapy system is a device that produces by acceleration high energy charged particles (e.g., electrons and protons...

42 CFR Appendix F to Part 75 - Standards for Licensing Radiographers, Nuclear Medicine Technologists, and Radiation Therapy...

Code of Federal Regulations, 2011 CFR

2011-10-01

... licensed as Radiographers, Nuclear Medicine Technologists, or Radiation Therapy Technologists. 2. Licenses... radiography, nuclear medicine technology, or radiation therapy technology. 2. Special eligibility to take the...-referenced examination in radiography, nuclear medicine technology, or radiation therapy technology shall be...

42 CFR Appendix F to Part 75 - Standards for Licensing Radiographers, Nuclear Medicine Technologists, and Radiation Therapy...

Code of Federal Regulations, 2012 CFR

2012-10-01

... licensed as Radiographers, Nuclear Medicine Technologists, or Radiation Therapy Technologists. 2. Licenses... radiography, nuclear medicine technology, or radiation therapy technology. 2. Special eligibility to take the...-referenced examination in radiography, nuclear medicine technology, or radiation therapy technology shall be...

42 CFR Appendix F to Part 75 - Standards for Licensing Radiographers, Nuclear Medicine Technologists, and Radiation Therapy...

Code of Federal Regulations, 2013 CFR

2013-10-01

... licensed as Radiographers, Nuclear Medicine Technologists, or Radiation Therapy Technologists. 2. Licenses... radiography, nuclear medicine technology, or radiation therapy technology. 2. Special eligibility to take the...-referenced examination in radiography, nuclear medicine technology, or radiation therapy technology shall be...

42 CFR Appendix F to Part 75 - Standards for Licensing Radiographers, Nuclear Medicine Technologists, and Radiation Therapy...

Code of Federal Regulations, 2014 CFR

2014-10-01

... licensed as Radiographers, Nuclear Medicine Technologists, or Radiation Therapy Technologists. 2. Licenses... radiography, nuclear medicine technology, or radiation therapy technology. 2. Special eligibility to take the...-referenced examination in radiography, nuclear medicine technology, or radiation therapy technology shall be...

21 CFR 892.5710 - Radiation therapy beam-shaping block.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Radiation therapy beam-shaping block. 892.5710... (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Therapeutic Devices § 892.5710 Radiation therapy beam-shaping block. (a) Identification. A radiation therapy beam-shaping block is a device made of a highly...

21 CFR 892.5710 - Radiation therapy beam-shaping block.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Radiation therapy beam-shaping block. 892.5710... (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Therapeutic Devices § 892.5710 Radiation therapy beam-shaping block. (a) Identification. A radiation therapy beam-shaping block is a device made of a highly...

21 CFR 892.5710 - Radiation therapy beam-shaping block.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Radiation therapy beam-shaping block. 892.5710... (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Therapeutic Devices § 892.5710 Radiation therapy beam-shaping block. (a) Identification. A radiation therapy beam-shaping block is a device made of a highly...

SU-F-T-323: A Post-Mastectomy Radiation Therapy Dose Distribution Study Using Nanodots and Films

DOE Office of Scientific and Technical Information (OSTI.GOV)

Qian, X; Vaidya, K; Puckett, L

Purpose: In post-mastectomy radiation therapy (RT), skin dose must be accurately estimated to assess skin reactions such as erythema, desquamation and necrosis. Planning systems cannot always provide accurate dosimetry for target volumes distal to skin. Therefore, in-vivo dosimetry is necessary. A female anthropomorphic phantom was used with optically stimulated luminescence dosimeters (nanoDots) to measure dose to chest wall skin. In addition, EBT2 films was employed to measure dose to left lung and heart in post-mastectomy RT. Methods: Films and nanoDots were calibrated under full buildup conditions at 100cm SAD for 6MV photons. Five pieces of films were placed between slabsmore » of Rando phantom to assess dose to left lung and heart. Two layers of 0.5cm thick bolus were used to cover the whole left chest. Six pairs of nanoDots were placed at medical and lateral aspects on the bolus surface, between the 0.5cm bolus layers, and under the bolus. Three control nanoDots were placed on chest wall to quantify imaging dose. The phantom was CT scanned with all dosimeters in place, and treatment planning was performed with tangential fields (200cGy). All dosimeters were contoured on CT and dose was extracted. NanoDots were read using nanoDot reader and films were scanned using film scanner. The measured and calculated doses were tabulated. Results: Dose to 12 nanoDots were evaluated. Dose variance for surface nanoDots were +3.8%, +2.7%, −5% and −9.8%. Those at lateral positions, with greater beam obliquity had larger variance than the medial positions. A similar trend was observed for other nanoDots (Table1). Point doses from films for heart and the left lung were 112.7cGy and 108.7cGy, with +10.2% and +9.04% deviation from calculated values, respectively. Conclusion: Dosimetry provided by the advanced planning system was verified using NanoDots and films. Both nanoDots and films provided good estimation of dose distribution in post-mastectomy RT.« less

Injector Element which Maintains a Constant Mean Spray Angle and Optimum Pressure Drop During Throttling by Varying the Geometry of Tangential Inlets

NASA Technical Reports Server (NTRS)

Trinh, Huu P. (Inventor); Myers, William Neill (Inventor)

2014-01-01

A method for determining the optimum inlet geometry of a liquid rocket engine swirl injector includes obtaining a throttleable level phase value, volume flow rate, chamber pressure, liquid propellant density, inlet injector pressure, desired target spray angle and desired target optimum delta pressure value between an inlet and a chamber for a plurality of engine stages. The tangential inlet area for each throttleable stage is calculated. The correlation between the tangential inlet areas and delta pressure values is used to calculate the spring displacement and variable inlet geometry. An injector designed using the method includes a plurality of geometrically calculated tangential inlets in an injection tube; an injection tube cap with a plurality of inlet slots slidably engages the injection tube. A pressure differential across the injector element causes the cap to slide along the injection tube and variably align the inlet slots with the tangential inlets.

Computational analysis of forebody tangential slot blowing

NASA Technical Reports Server (NTRS)

Gee, Ken; Agosta-Greenman, Roxana M.; Rizk, Yehia M.; Schiff, Lewis B.; Cummings, Russell M.

1994-01-01

An overview of the computational effort to analyze forebody tangential slot blowing is presented. Tangential slot blowing generates side force and yawing moment which may be used to control an aircraft flying at high-angle-of-attack. Two different geometries are used in the analysis: (1) The High Alpha Research Vehicle; and (2) a generic chined forebody. Computations using the isolated F/A-18 forebody are obtained at full-scale wind tunnel test conditions for direct comparison with available experimental data. The effects of over- and under-blowing on force and moment production are analyzed. Time-accurate solutions using the isolated forebody are obtained to study the force onset timelag of tangential slot blowing. Computations using the generic chined forebody are obtained at experimental wind tunnel conditions, and the results compared with available experimental data. This computational analysis compliments the experimental results and provides a detailed understanding of the effects of tangential slot blowing on the flow field about simple and complex geometries.

Mertk on tumor macrophages is a therapeutic target to prevent tumor recurrence following radiation therapy

PubMed Central

Crittenden, Marka R.; Baird, Jason; Friedman, David; Savage, Talicia; Uhde, Lauren; Alice, Alejandro; Cottam, Benjamin; Young, Kristina; Newell, Pippa; Nguyen, Cynthia; Bambina, Shelly; Kramer, Gwen; Akporiaye, Emmanuel; Malecka, Anna; Jackson, Andrew; Gough, Michael J.

2016-01-01

Radiation therapy provides a means to kill large numbers of cancer cells in a controlled location resulting in the release of tumor-specific antigens and endogenous adjuvants. However, by activating pathways involved in apoptotic cell recognition and phagocytosis, irradiated cancer cells engender suppressive phenotypes in macrophages. We demonstrate that the macrophage-specific phagocytic receptor, Mertk is upregulated in macrophages in the tumor following radiation therapy. Ligation of Mertk on macrophages results in anti-inflammatory cytokine responses via NF-kB p50 upregulation, which in turn limits tumor control following radiation therapy. We demonstrate that in immunogenic tumors, loss of Mertk is sufficient to permit tumor cure following radiation therapy. However, in poorly immunogenic tumors, TGFb inhibition is also required to result in tumor cure following radiation therapy. These data demonstrate that Mertk is a highly specific target whose absence permits tumor control in combination with radiation therapy. PMID:27602953

Adjuvant and Salvage Radiation Therapy After Prostatectomy: American Society for Radiation Oncology/American Urological Association Guidelines

DOE Office of Scientific and Technical Information (OSTI.GOV)

Valicenti, Richard K., E-mail: Richard.valicenti@ucdmc.ucdavis.edu; Thompson, Ian; Albertsen, Peter

Purpose: The purpose of this guideline was to provide a clinical framework for the use of radiation therapy after radical prostatectomy as adjuvant or salvage therapy. Methods and Materials: A systematic literature review using PubMed, Embase, and Cochrane database was conducted to identify peer-reviewed publications relevant to the use of radiation therapy after prostatectomy. The review yielded 294 articles; these publications were used to create the evidence-based guideline statements. Additional guidance is provided as Clinical Principles when insufficient evidence existed. Results: Guideline statements are provided for patient counseling, use of radiation therapy in the adjuvant and salvage contexts, defining biochemicalmore » recurrence, and conducting a restaging evaluation. Conclusions: Physicians should offer adjuvant radiation therapy to patients with adverse pathologic findings at prostatectomy (ie, seminal vesicle invastion, positive surgical margins, extraprostatic extension) and salvage radiation therapy to patients with prostate-specific antigen (PSA) or local recurrence after prostatectomy in whom there is no evidence of distant metastatic disease. The offer of radiation therapy should be made in the context of a thoughtful discussion of possible short- and long-term side effects of radiation therapy as well as the potential benefits of preventing recurrence. The decision to administer radiation therapy should be made by the patient and the multidisciplinary treatment team with full consideration of the patient's history, values, preferences, quality of life, and functional status. The American Society for Radiation Oncology and American Urological Association websites show this guideline in its entirety, including the full literature review.« less

Role of Definitive Radiation Therapy in Carcinoma of Unknown Primary in the Abdomen and Pelvis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kelly, Patrick; Das, Prajnan; Varadhachary, Gauri R.

2012-04-01

Objectives: Carcinoma of unknown primary (CUP) in the abdomen and pelvis is a heterogeneous group of cancers with no standard treatment. Considered by many to be incurable, these patients are often treated with chemotherapy alone. In this study, we determined the effectiveness of radiation therapy in combination with chemotherapy in patients with CUP in the abdomen and pelvis. Patients and Methods: Medical records were reviewed for 37 patients with CUP treated with radiation therapy for disease located in the soft tissues and/or nodal basins of the abdomen and pelvis at University of Texas M.D. Anderson Cancer between 2002 and 2009.more » All patients underwent chemotherapy, either before or concurrent with radiation therapy. Patients were selected for radiation therapy on the basis of histologic type, disease extent, and prior therapy response. Twenty patients underwent definitive radiation therapy (defined as radiation therapy targeting all known disease sites with at least 45 Gy) and 17 patients underwent palliative radiation therapy. Only 6 patients had surgical resection of their disease. Patient and treatment characteristics were extracted and the endpoints of local disease control, progression-free survival (PFS), overall survival (OS), and treatment-related toxicity incidence were analyzed. Results: The 2-year PFS and OS rates for the entire cohort were 32% and 57%, respectively. However, in patients treated with definitive radiation therapy, the rates were 48% and 76%, and 7 patients lived more than 3 years after treatment with no evidence of disease progression. Nevertheless, radiation-associated toxicity was significant in this cohort, as 40% experienced Grade 2 or higher late toxicities. Conclusions: The use of definitive radiation therapy should be considered in selected patients with CUP in the soft tissues or nodal basins of the abdomen and pelvis.« less

Radiation Therapy Administration and Survival in Stage I/II Extranodal Marginal Zone B-Cell Lymphoma of Mucosa-Associated Lymphoid Tissue

DOE Office of Scientific and Technical Information (OSTI.GOV)

Olszewski, Adam J., E-mail: adam_olszewski@brown.edu; Desai, Amrita

2014-03-01

Purpose: To determine the factors associated with the use of radiation therapy and associated survival outcomes in early-stage marginal zone lymphoma of the mucosa-associated lymphoid tissue (MALT). Methods and Materials: We extracted data on adult patients with stage I/II MALT lymphoma diagnoses between 1998 and 2010 recorded in the Surveillance, Epidemiology, and End Results (SEER) database. We studied factors associated with radiation therapy administration in a logistic regression model and described the cumulative incidence of lymphoma-related death (LRD) according to receipt of the treatment. The association of radiation therapy with survival was explored in multivariate models with adjustment for immortalmore » time bias. Results: Of the 7774 identified patients, 36% received radiation therapy as part of the initial course of treatment. Older patients; black or Hispanic men; white, Hispanic, and black women; and socioeconomically disadvantaged and underinsured patients had a significantly lower chance of receiving radiation therapy. Radiation therapy administration was associated with a lower chance of LRD in most sites. In cutaneous, ocular, and salivary MALT lymphomas, the 5-year estimate of LRD after radiation therapy was 0%. The association of radiation therapy with overall survival in different lymphoma sites was heterogeneous, and statistically significant in cutaneous (hazard ratio 0.45, P=.009) and ocular (hazard ratio 0.47, P<.0001) locations after multivariate adjustment. Conclusions: Demographic factors are associated with the use of radiation therapy in MALT lymphoma. Clinicians should be sensitive to those disparities because the administration of radiation therapy may be associated with improved survival, particularly in cutaneous and ocular lymphomas.« less

Job satisfaction among radiation therapy educators.

PubMed

Swafford, Larry G; Legg, Jeffrey S

2007-01-01

Job satisfaction is one of the most consistent variables related to employee retention and is especially relevant considering the shortage of radiation therapists and radiation therapy educators in the United States. To investigate job satisfaction levels among radiation therapy educators certified by the American Registry of Radiologic Technologists and employed in programs accredited by the Joint Review Committee on Education in Radiologic Technology. The long form of the Minnesota Satisfaction Questionnaire (MSQ) was mailed to 158 radiation therapy educators to measure job satisfaction. Overall job satisfaction and subscales were calculated based on MSQ methodology. A total of 90 usable surveys were returned for a 56.9% response rate. With a "general satisfaction" score of 69.64, radiation therapy educators ranked in the lowest 25th percentile of the nondisabled norm scale for job satisfaction. Respondents reported higher degrees of job satisfaction on the moral values, social service and achievement subscales. Lower job satisfaction levels were associated with the company policies and practices, advancement and compensation subscales. Radiation therapy educators report low job satisfaction. Educational institutions must tailor recruitment and retention efforts to better reflect the positive aspects of being a radiation therapy educator. Furthermore, improving retention and recruitment efforts might help offset the current shortages of radiation therapy educators and, ultimately, clinical radiation therapists.

Radiation therapy infrastructure and human resources in low- and middle-income countries: present status and projections for 2020.

PubMed

Datta, Niloy R; Samiei, Massoud; Bodis, Stephan

2014-07-01

Radiation therapy, a key component of cancer management, is required in more than half of new cancer patients, particularly in low- and middle-income countries (LMICs). The projected rise in cancer incidence over the next decades in LMICs will result in an increasing demand for radiation therapy services. Considering the present cancer incidence and that projected for 2020 (as listed in GLOBOCAN), we evaluated the current and anticipated needs for radiation therapy infrastructure and staffing by 2020 for each of the LMICs. Based on World Bank classification, 139 countries fall in the category of LMICs. Details of teletherapy, radiation oncologists, medical physicists, and radiation therapy technologists were available for 84 LMICs from the International Atomic Energy Agency-Directory of Radiotherapy Centres (IAEA-DIRAC) database. Present requirements and those for 2020 were estimated according to recommendations from the IAEA and European Society for Radiotherapy & Oncology (ESTRO-QUARTS). Only 4 of the 139 LMICs have the requisite number of teletherapy units, and 55 (39.5%) have no radiation therapy facilities at present. Patient access to radiation therapy in the remaining 80 LMICs ranges from 2.3% to 98.8% (median: 36.7%). By 2020, these 84 LMICs would additionally need 9169 teletherapy units, 12,149 radiation oncologists, 9915 medical physicists, and 29,140 radiation therapy technologists. Moreover, de novo radiation therapy facilities would have to be considered for those with no services. Twelve pragmatic steps are proposed for consideration at national and international levels to narrow the gap in radiation therapy access. Multipronged and coordinated action from all national and international stakeholders is required to develop realistic strategies to curb this impending global crisis. Copyright © 2014 Elsevier Inc. All rights reserved.

Radiation Therapy Infrastructure and Human Resources in Low- and Middle-Income Countries: Present Status and Projections for 2020

DOE Office of Scientific and Technical Information (OSTI.GOV)

Datta, Niloy R., E-mail: niloyranjan.datta@ksa.ch; Samiei, Massoud; Bodis, Stephan

2014-07-01

Purpose: Radiation therapy, a key component of cancer management, is required in more than half of new cancer patients, particularly in low- and middle-income countries (LMICs). The projected rise in cancer incidence over the next decades in LMICs will result in an increasing demand for radiation therapy services. Considering the present cancer incidence and that projected for 2020 (as listed in GLOBOCAN), we evaluated the current and anticipated needs for radiation therapy infrastructure and staffing by 2020 for each of the LMICs. Methods and Materials: Based on World Bank classification, 139 countries fall in the category of LMICs. Details ofmore » teletherapy, radiation oncologists, medical physicists, and radiation therapy technologists were available for 84 LMICs from the International Atomic Energy Agency–Directory of Radiotherapy Centres (IAEA-DIRAC) database. Present requirements and those for 2020 were estimated according to recommendations from the IAEA and European Society for Radiotherapy and Oncology (ESTRO-QUARTS). Results: Only 4 of the 139 LMICs have the requisite number of teletherapy units, and 55 (39.5%) have no radiation therapy facilities at present. Patient access to radiation therapy in the remaining 80 LMICs ranges from 2.3% to 98.8% (median: 36.7%). By 2020, these 84 LMICs would additionally need 9169 teletherapy units, 12,149 radiation oncologists, 9915 medical physicists, and 29,140 radiation therapy technologists. Moreover, de novo radiation therapy facilities would have to be considered for those with no services. Conclusions: Twelve pragmatic steps are proposed for consideration at national and international levels to narrow the gap in radiation therapy access. Multipronged and coordinated action from all national and international stakeholders is required to develop realistic strategies to curb this impending global crisis.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shinohara, Eric T.; Mitra, Nandita; Guo Mengye

Purpose: Intrahepatic cholangiocarcinomas (IHC) are rare tumors for which large randomized studies regarding the use of radiation are not available. The purpose of this study was to examine the role of adjuvant and definitive radiation therapy in the treatment of IHC in a large group of patients. Methods and Materials: This is a retrospective analysis of 3,839 patients with IHC collected from the Surveillance, Epidemiology, and End Results (SEER) database. The primary endpoint was overall survival (OS). Results: Patients received either surgery alone (25%), radiation therapy alone (10%), surgery and adjuvant radiation therapy (7%) or no treatment (58%). The medianmore » age of the patient population was 73 years (range, 22-102 years); 52% of patients were male and 81% were Caucasian. Median OS was 11 (95% confidence interval [CI], 9-13), 6 (95% CI, 5-6), 7 (95% CI, 6-8), and 3 months for surgery and adjuvant radiation therapy, sugery alone, radiation therapy alone, and no treatment, respectively. The OS was significantly different between surgery alone and surgery and adjuvant radiation therapy (p = 0.014) and radiation therapy alone and no treatment (p < 0.0001). Use of surgery and adjuvant radiation therapy conferred the greatest benefit on OS (HR = 0.40; 95% CI, 0.34-0.47), followed by surgery alone (hazard ratio [HR], 0.49; 95% CI, 0.44-0.54) and radiation therapy alone (HR, 0.68; 95% CI, 0.59-0.77) compared with no treatment, on multivariate analysis. Propensity score adjusted hazard ratios (controlling for age, race/ethnicity, stage, and year of diagnosis) were also significant (surgery and adjuvant radiation therapy vs. surgery alone (HR, 0.82; 95% CI, 0.70-0.96); radiation therapy alone vs. no treatment (HR, 0.67; 95% CI, 0.58-0.76)). Conclusions: The study results suggest that adjuvant and definitive radiation treatment prolong survival, although cure rates remain low. Future studies should evaluate the addition of chemotherapy and biologics to the treatment of IHC.« less

Outcomes in real-world practice are different than cooperative trial for elderly patients with early breast cancer treated with adjuvant radiation therapy.

PubMed

Chu, Quyen D; Zhou, Meijiao; Peddi, Prakash; Medeiros, Kaelen L; Wu, Xiao-Cheng

2018-06-01

The Cancer and Leukemia Group B 9,343 demonstrated that postoperative radiation can be safely omitted in women ≥70 years who underwent breast-conserving therapy for clinical stage I (T1N0M0) estrogen receptor positive breast cancer treated with antihormonal therapy. Whether such results are observed in real-world population is unknown. In this hospital-based data, we report the survival outcomes of patients who received adjuvant radiation therapy versus those who did not. Using the National Cancer Data Base, we evaluated a cohort of 47,358 women with newly diagnosed breast cancer between 2004 and 2011 who underwent a lumpectomy and antihormonal therapy with the following criteria: age ≥70 years, clinical stage I, estrogen receptor positive, and negative margins. Patients were stratified into 2 groups: (1) radiation therapy and (2) no radiation therapy. Propensity score matching was used to compensate for differences in demographic and clinical characteristics of the patients. Univariate and multivariable survival analysis were employed to determine factors associated with overall survival. The 5-year overall survival after propensity score matching was 87.2% for radiation therapy and 79.4% for no radiation therapy (P < .0001). The median survival time was 113.7 months for radiation therapy and 105.2 months for no radiation therapy. After adjusting for sociodemographic and clinical factors, the risk of overall deaths was significantly higher for those not receiving radiation therapy (hazard ratio = 1.66; 95% confidence interval, 1.54-1.79). Other significant adjusted predictors (P < .05) of poor overall survival were, advanced age, comprehensive community cancer program, facility location, poorly differentiated tumor, and high comorbidity index. Patients who received radiation therapy had better survival outcomes than those who did not, revealing discordance between results of randomized trials and real-world setting. Copyright © 2018 Elsevier Inc. All rights reserved.

[Highly quality-controlled radiation therapy].

PubMed

Shirato, Hiroki

2005-04-01

Advanced radiation therapy for intracranial disease has focused on set-up accuracy for the past 15 years. However, quality control in the prescribed dose is actually as important as the tumor set-up in radiation therapy. Because of the complexity of the three-dimensional radiation treatment planning system in recent years, the highly quality-controlled prescription of the dose has now been reappraised as the mainstream to improve the treatment outcome of radiation therapy for intracranial disease. The Japanese Committee for Quality Control of Radiation Therapy has developed fundamental requirements such as a QC committee in each hospital, a medical physicist, dosimetrists (QC members), and an external audit.

Design of tangential viewing phase contrast imaging for turbulence measurements in JT-60SA

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tanaka, K., E-mail: ktanaka@nifs.ac.jp; Department of Advanced Energy Engineering, Kyushu University, Kasuga, Fukuoka 816-8580; Coda, S.

2016-11-15

A tangential viewing phase contrast imaging system is being designed for the JT-60SA tokamak to investigate microturbulence. In order to obtain localized information on the turbulence, a spatial-filtering technique is applied, based on magnetic shearing. The tangential viewing geometry enhances the radial localization. The probing laser beam is injected tangentially and traverses the entire plasma region including both low and high field sides. The spatial resolution for an Internal Transport Barrier discharge is estimated at 30%–70% of the minor radius at k = 5 cm{sup −1}, which is the typical expected wave number of ion scale turbulence such as ionmore » temperature gradient/trapped electron mode.« less

Oral mucositis - self-care

MedlinePlus

Cancer treatment - mucositis; Cancer treatment - mouth pain; Cancer treatment - mouth sores; Chemotherapy - mucositis; Chemotherapy - mouth pain; Chemotherapy - mouth sores; Radiation therapy - mucositis; Radiation therapy - mouth pain; Radiation therapy - mouth ...

Evaluation of Far-Field Boundary Conditions for the Gust Response Problem

NASA Technical Reports Server (NTRS)

Scott, James R.; Kreider, Kevin L.; Heminger, John A.

2002-01-01

This paper presents a detailed situ dy of four far-field boundary conditions used in solving the single airfoil gust response problem. The boundary conditions, examined are the partial Sommerfeld radiation condition with only radial derivatives, the full Sommerfeld radiation condition with both radial and tangential derivatives, the Bayliss-Turkel condition of order one, and the Hagstrom-Hariharan condition of order one. The main objectives of the study were to determine which far-field boundary condition was most accurate, which condition was least sensitive to changes in grid. and which condition was best overall in terms of both accuracy and efficiency. Through a systematic study of the flat plate gust response problem, it was determined that the Hagstrom-Hariharan condition was most accurate, the Bayliss-Turkel condition was least sensitive to changes in grid, and Bayliss-Turkel was best in terms of both accuracy and efficiency.

Relativistic shock waves in an electron-positron plasma

NASA Astrophysics Data System (ADS)

Tsintsadze, Levan N.

1995-12-01

The equations describing the detailed structure of radiation electromagnetic hydrodynamics for a relativistically hot electron-positron plasma are derived. Various discontinuities are studied by these equations. It is shown that the dependence of the electron (positron) mass on the temperature changes the structure of discontinuities, including shock waves, both qualitatively and quantitatively. Steady radiative shocks are considered, which can arise in steady flows, and which also can be used to describe the propagation of shocks when the shock thickness is very small as compared to the characteristic length over which the ambient medium changes significantly. First, the magnetohydrodynamic shock wave is treated as a discontinuity and jump relations, which relate the equilibrium states of the upstream and downstream plasma far from the front, are derived. Then the structure of the front itself is considered and tangential, contact (or entropy) and rotational discontinuities are investigated.

DOE Research Contributions to Radiation and Cancer Therapy

Science.gov Websites

dropdown arrow Site Map A-Z Index Menu Synopsis DOE Research Contributions to Radiation and Cancer Therapy research has made many contributions to radiation and cancer therapy, including PEREGRINE and Boron Neutron planning radiation treatment for cancer patients. About 90 percent of radiation treatment patients receive

Music therapy CD creation for initial pediatric radiation therapy: a mixed methods analysis.

PubMed

Barry, Philippa; O'Callaghan, Clare; Wheeler, Greg; Grocke, Denise

2010-01-01

A mixed methods research design was used to investigate the effects of a music therapy CD (MTCD) creation intervention on pediatric oncology patients' distress and coping during their first radiation therapy treatment. The music therapy method involved children creating a music CD using interactive computer-based music software, which was "remixed" by the music therapist-researcher to extend the musical material. Eleven pediatric radiation therapy outpatients aged 6 to 13 years were randomly assigned to either an experimental group, in which they could create a music CD prior to their initial treatment to listen to during radiation therapy, or to a standard care group. Quantitative and qualitative analyses generated multiple perceptions from the pediatric patients, parents, radiation therapy staff, and music therapist-researcher. Ratings of distress during initial radiation therapy treatment were low for all children. The comparison between the two groups found that 67% of the children in the standard care group used social withdrawal as a coping strategy, compared to 0% of the children in the music therapy group; this trend approached significance (p = 0.076). MTCD creation was a fun, engaging, and developmentally appropriate intervention for pediatric patients, which offered a positive experience and aided their use of effective coping strategies to meet the demands of their initial radiation therapy treatment.

National Cancer Database Analysis of Proton Versus Photon Radiation Therapy in Non-Small Cell Lung Cancer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Higgins, Kristin A., E-mail: kristin.higgins@emory.edu; Winship Cancer Institute, Emory University, Atlanta, Georgia; O'Connell, Kelli

Purpose: To analyze outcomes and predictors associated with proton radiation therapy for non-small cell lung cancer (NSCLC) in the National Cancer Database. Methods and Materials: The National Cancer Database was queried to capture patients with stage I-IV NSCLC treated with thoracic radiation from 2004 to 2012. A logistic regression model was used to determine the predictors for utilization of proton radiation therapy. The univariate and multivariable association with overall survival were assessed by Cox proportional hazards models along with log–rank tests. A propensity score matching method was implemented to balance baseline covariates and eliminate selection bias. Results: A total of 243,822more » patients (photon radiation therapy: 243,474; proton radiation therapy: 348) were included in the analysis. Patients in a ZIP code with a median income of <$46,000 per year were less likely to receive proton treatment, with the income cohort of $30,000 to $35,999 least likely to receive proton therapy (odds ratio 0.63 [95% confidence interval (CI) 0.44-0.90]; P=.011). On multivariate analysis of all patients, non-proton therapy was associated with significantly worse survival compared with proton therapy (hazard ratio 1.21 [95% CI 1.06-1.39]; P<.01). On propensity matched analysis, proton radiation therapy (n=309) was associated with better 5-year overall survival compared with non-proton radiation therapy (n=1549), 22% versus 16% (P=.025). For stage II and III patients, non-proton radiation therapy was associated with worse survival compared with proton radiation therapy (hazard ratio 1.35 [95% CI 1.10-1.64], P<.01). Conclusions: Thoracic radiation with protons is associated with better survival in this retrospective analysis; further validation in the randomized setting is needed to account for any imbalances in patient characteristics, including positron emission tomography–computed tomography staging.« less

Axillary irradiation omitting axillary dissection in breast cancer: is there a role for shoulder-sparing proton therapy?

PubMed

Farace, P; Deidda, M A; Amichetti, M

2015-10-01

The recent EORTC 10981-22023 AMAROS trial showed that axillary radiotherapy and axillary lymph node dissection provide comparable local control and reduced lymphoedema in the irradiated group. However, no significant differences between the two groups in range of motion and quality of life were reported. It has been acknowledged that axillary irradiation could have induced some toxicity, particularly shoulder function impairment. In fact, conventional breast irradiation by tangential beams has to be modified to achieve full-dose coverage of the axillary nodes, including in the treatment field a larger portion of the shoulder structures. In this scenario, alternative irradiation techniques were discussed. Compared with modern photon techniques, axillary irradiation by proton therapy has the potential for sparing the shoulder without detrimental increase of the medium-to-low doses to the other normal tissues.

Evaluation of Delivery Costs for External Beam Radiation Therapy and Brachytherapy for Locally Advanced Cervical Cancer Using Time-Driven Activity-Based Costing.

PubMed

Bauer-Nilsen, Kristine; Hill, Colin; Trifiletti, Daniel M; Libby, Bruce; Lash, Donna H; Lain, Melody; Christodoulou, Deborah; Hodge, Constance; Showalter, Timothy N

2018-01-01

To evaluate the delivery costs, using time-driven activity-based costing, and reimbursement for definitive radiation therapy for locally advanced cervical cancer. Process maps were created to represent each step of the radiation treatment process and included personnel, equipment, and consumable supplies used to deliver care. Personnel were interviewed to estimate time involved to deliver care. Salary data, equipment purchasing information, and facilities costs were also obtained. We defined the capacity cost rate (CCR) for each resource and then calculated the total cost of patient care according to CCR and time for each resource. Costs were compared with 2016 Medicare reimbursement and relative value units (RVUs). The total cost of radiation therapy for cervical cancer was $12,861.68, with personnel costs constituting 49.8%. Brachytherapy cost $8610.68 (66.9% of total) and consumed 423 minutes of attending radiation oncologist time (80.0% of total). External beam radiation therapy cost $4055.01 (31.5% of total). Personnel costs were higher for brachytherapy than for the sum of simulation and external beam radiation therapy delivery ($4798.73 vs $1404.72). A full radiation therapy course provides radiation oncologists 149.77 RVUs with intensity modulated radiation therapy or 135.90 RVUs with 3-dimensional conformal radiation therapy, with total reimbursement of $23,321.71 and $16,071.90, respectively. Attending time per RVU is approximately 4-fold higher for brachytherapy (5.68 minutes) than 3-dimensional conformal radiation therapy (1.63 minutes) or intensity modulated radiation therapy (1.32 minutes). Time-driven activity-based costing was used to calculate the total cost of definitive radiation therapy for cervical cancer, revealing that brachytherapy delivery and personnel resources constituted the majority of costs. However, current reimbursement policy does not reflect the increased attending physician effort and delivery costs of brachytherapy. We hypothesize that the significant discrepancy between treatment costs and physician effort versus reimbursement may be a potential driver of reported national trends toward poor compliance with brachytherapy, and we suggest re-evaluation of payment policies to incentivize quality care. Copyright © 2017 Elsevier Inc. All rights reserved.

[A recent trial of chemo-radiation with S-1 against gastric cancer].

PubMed

Saikawa, Yoshiro; Kiyota, Tsuyoshi; Nakamura, Rieko; Wada, Norihito; Yoshida, Masashi; Kubota, Tetsuro; Kumai, Koichiro; Shigematsu, Naoyuki; Kubo, Atsushi; Kitajima, Masaki

2006-06-01

A recent development of novel anticancer agents like S-1, CPT-11 or taxanes has improved a therapeutic outcome for advanced gastric cancer, while conventional anticancer agents showed less anticancer effect against gastric cancer. The present main drug in Japan is S-1, which is easily used for outpatient with a high efficacy rate and low toxicity, also shows better effect in combination with other anticancer drugs than S-1 alone. In the present article, we demonstrated significant meaning of additional radiation therapy with anticancer drugs like S-1. With novel anticancer drugs like S-1, we will expose a clinical advantage and appropriateness for chemo-radiation therapy against gastric cancer discussed in the present references according to chemo-radiation therapy. Although chemo-radiation therapy has been recognized as one of the standard therapies for gastric cancer in Western countries, radiation therapy was selected in Japan for palliation therapy of recurrent disease or a terminal cancer to improve patients' QOL. On the other hand, we demonstrated in our trial of chemo-radiation therapy with S-1/low-dose CDDP/radiation (TSLDR), which was applied to initial treatment against highly advanced Stage IV gastric cancer and revealed the usefulness of the regimen in anticancer effect and toxicity. In addition, chemo-radiation therapy including novel anticancer agents like S-1 will be discussed based on various kinds of view points, expecting a better clinical outcome of multimodal therapies against advanced gastric cancer.

Retrospective study of orthovoltage radiation therapy for nasal tumors in 42 dogs.

PubMed

Northrup, N C; Etue, S M; Ruslander, D M; Rassnick, K M; Hutto, D L; Bengtson, A; Rand, W; Moore, A S

2001-01-01

Megavoltage radiation therapy currently is the standard of care for dogs with nasal tumors. Some studies report that surgery and adjunctive orthovoltage radiation therapy result in longer control of these tumors than does megavoltage radiation therapy alone. This study reports less effective control of nasal tumors in dogs treated with surgery and orthovoltage radiation than previously observed, supporting the superiority of megavoltage radiation therapy for these tumors. In addition, this study suggests 2 new prognostic indicators for dogs with nasal tumors and describes toxicity associated with surgery and orthovoltage therapy. Forty-two dogs with nasal tumors were treated with surgical cytoreduction and 48 Gy orthovoltage radiation therapy administered in twelve 4-Gy fractions. Median survival was 7.4 months. One- and 2-year survival rates were 37% and 17%, respectively. Dogs with facial deformity had shorter survival than those without deformity (P = .005). Dogs with resolution of clinical signs after treatment had longer survival than those with chronic nasal signs (P = .0001). Acute radiation toxicity was moderate to severe for skin and eye and negligible for oral mucosa. Toxicity healed within 1 month after radiation therapy. Late toxicity was mild, but 70% of evaluable dogs experienced persistent ocular signs. Only 39% of dogs achieved a disease-free period.

External Beam Radiation Therapy for Cancer

Cancer.gov

External beam radiation therapy is used to treat many types of cancer. it is a local treatment, where a machine aims radiation at your cancer. Learn more about different types of external beam radiation therapy, and what to expect if you're receiving treatment.

Oxygen and Perfusion Kinetics in Response to Fractionated Radiation Therapy in FaDu Head and Neck Cancer Xenografts Are Related to Treatment Outcome

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hu, Fangyao; Vishwanath, Karthik; Salama, Joseph K.

Purpose: To test whether oxygenation kinetics correlate with the likelihood for local tumor control after fractionated radiation therapy. Methods and Materials: We used diffuse reflectance spectroscopy to noninvasively measure tumor vascular oxygenation and total hemoglobin concentration associated with radiation therapy of 5 daily fractions (7.5, 9, or 13.5 Gy/d) in FaDu xenografts. Spectroscopy measurements were obtained immediately before each daily radiation fraction and during the week after radiation therapy. Oxygen saturation and total hemoglobin concentration were computed using an inverse Monte Carlo model. Results: First, oxygenation kinetics during and after radiation therapy, but before tumor volumes changed, were associated with localmore » tumor control. Locally controlled tumors exhibited significantly faster increases in oxygenation after radiation therapy (days 12-15) compared with tumors that recurred locally. Second, within the group of tumors that recurred, faster increases in oxygenation during radiation therapy (day 3-5 interval) were correlated with earlier recurrence times. An area of 0.74 under the receiver operating characteristic curve was achieved when classifying the local control tumors from all irradiated tumors using the oxygen kinetics with a logistic regression model. Third, the rate of increase in oxygenation was radiation dose dependent. Radiation doses ≤9.5 Gy/d did not initiate an increase in oxygenation, whereas 13.5 Gy/d triggered significant increases in oxygenation during and after radiation therapy. Conclusions: Additional confirmation is required in other tumor models, but these results suggest that monitoring tumor oxygenation kinetics could aid in the prediction of local tumor control after radiation therapy.« less

Precision Oncology and Genomically Guided Radiation Therapy: A Report From the American Society for Radiation Oncology/American Association of Physicists in Medicine/National Cancer Institute Precision Medicine Conference.

PubMed

Hall, William A; Bergom, Carmen; Thompson, Reid F; Baschnagel, Andrew M; Vijayakumar, Srinivasan; Willers, Henning; Li, X Allen; Schultz, Christopher J; Wilson, George D; West, Catharine M L; Capala, Jacek; Coleman, C Norman; Torres-Roca, Javier F; Weidhaas, Joanne; Feng, Felix Y

2018-06-01

To summarize important talking points from a 2016 symposium focusing on real-world challenges to advancing precision medicine in radiation oncology, and to help radiation oncologists navigate the practical challenges of precision, radiation oncology. The American Society for Radiation Oncology, American Association of Physicists in Medicine, and National Cancer Institute cosponsored a meeting on precision medicine in radiation oncology. In June 2016 numerous scientists, clinicians, and physicists convened at the National Institutes of Health to discuss challenges and future directions toward personalized radiation therapy. Various breakout sessions were held to discuss particular components and approaches to the implementation of personalized radiation oncology. This article summarizes the genomically guided radiation therapy breakout session. A summary of existing genomic data enabling personalized radiation therapy, ongoing clinical trials, current challenges, and future directions was collected. The group attempted to provide both a current overview of data that radiation oncologists could use to personalize therapy, along with data that are anticipated in the coming years. It seems apparent from the provided review that a considerable opportunity exists to truly bring genomically guided radiation therapy into clinical reality. Genomically guided radiation therapy is a necessity that must be embraced in the coming years. Incorporating these data into treatment recommendations will provide radiation oncologists with a substantial opportunity to improve outcomes for numerous cancer patients. More research focused on this topic is needed to bring genomic signatures into routine standard of care. Published by Elsevier Inc.

Measuring safety culture: Application of the Hospital Survey on Patient Safety Culture to radiation therapy departments worldwide.

PubMed

Leonard, Sarah; O'Donovan, Anita

Minimizing errors and improving patient safety has gained prominence worldwide in high-risk disciplines such as radiation therapy. Patient safety culture has been identified as an important factor in reducing the incidence of adverse events and improving patient safety in the health care setting. The aim of distributing the Hospital Survey on Patient Safety Culture (HSPSC) to radiation therapy departments worldwide was to assess the current status of safety culture, identify areas for improvement and areas that excel, examine factors that influence safety culture, and raise staff awareness. The safety culture in radiation therapy departments worldwide was evaluated by distributing the HSPSC. A total of 266 participants were recruited from radiation therapy departments and included radiation oncologists, radiation therapists, physicists, and dosimetrists. The positive percent scores for the 12 dimensions of the HSPSC varied from 50% to 79%. The highest composite score among the 12 dimensions was teamwork within units; the lowest composite score was handoffs and transitions. The results indicated that health care professionals in radiation therapy departments felt positively toward patient safety. The HSPSC was successfully applied to radiation therapy departments and provided valuable insight into areas of potential improvement such as teamwork across units, staffing, and handoffs and transitions. Managers and policy makers in radiation therapy may use this assessment tool for focused improvement efforts toward patient safety culture. Copyright © 2017 American Society for Radiation Oncology. Published by Elsevier Inc. All rights reserved.

What to Know about External Beam Radiation Therapy

MedlinePlus

... Radiation Therapy: What To Know About External Beam Radiation Therapy Before treatment starts: You will meet with a doctor or ... and show the therapist where to aim the radiation. When you go for treatment: ■ Don’t have powder, deodorant, Band-Aids ® , or ...

Tangential gunshot wound with MagSafe ammunition.

PubMed

Rapkiewicz, Amy V; Tamburri, Robert; Basoa, Mark E; Catanese, Charles A

2005-09-01

MagSafe ammunition is a type of unconventional prefragmented ammunition. A fatal tangential gunshot wound involving MagSafe ammunition is presented. The ammunition and wound characteristics are discussed.

Synergizing Radiation Therapy and Immunotherapy for Curing Incurable Cancers: Opportunities and Challenges

PubMed Central

Hodge, James W.; Guha, Chandan; Neefjes, Jacques; Gulley, James L.

2012-01-01

The combination of radiation therapy and immunotherapy holds particular promise as a strategy for cancer therapeutics. There is evidence that immunotherapy is most beneficial alone when employed early in the disease process or in combination with standard therapies (e.g., radiation) later in the disease process. Indeed, radiation may act synergistically with immunotherapy to enhance immune responses, inhibit immunosuppression, and/or alter the phenotype of tumor cells, thus rendering them more susceptible to immune-mediated killing. Furthermore, as monotherapies, both immunotherapy and radiation may be insufficient to eliminate tumor masses. However, following immunization with a cancer vaccine, the destruction of even a small percentage of tumor cells by radiation could result in cross-priming and presentation of tumor antigens to the immune system, thereby potentiating antitumor responses. Learning how to exploit radiation-induced changes to tumor-cell antigens, and how to induce effective immune responses to these cumulatively immunogenic stimuli, is an exciting frontier in cancer therapy research. This review examines a) mechanisms by which many forms of radiation therapy can induce or augment antitumor immune responses and b) preclinical systems that demonstrate that immunotherapy can be effectively combined with radiation therapy. Finally, we review current clinical trials where standard-of-care radiation therapy is being combined with immunotherapy. PMID:18777956

Design of tangential multi-energy soft x-ray camera for NSTX-U

NASA Astrophysics Data System (ADS)

Delgado-Aparicio, Luis F.; Maddox, J.; Pablant, N.; Hill, K.; Bitter, M.; Stratton, B.; Efthimion, Phillip

2016-10-01

For tokamaks and future facilities to operate safely in a high-pressure long-pulse discharge, it is imperative to address key issues associated with impurity sources, core transport and high-Z impurity accumulation. Multi-energy SXR imaging provides a unique opportunity for measuring, simultaneously, a variety of important plasma properties (Te, nZ and ΔZeff). A new tangential multi-energy soft x-ray pin-hole camera is being design to sample the continuum- and line-emission from low-, medium- and high-Z impurities. This new x-ray diagnostic will be installed on an equatorial midplane port of NSTX-U tokamak and will measure the radial structure of the photon emissivity with a radial resolution below 1 cm at a 500 Hz frame rate and a photon-energy resolution of 500 eV. The layout and response expected of the new system will be shown for different plasma conditions and impurity concentrations. The effect of toroidal rotation driving poloidal asymmetries in the core radiation is also addressed. This effort is designed to contribute to the near- and long-term highest priority research goals for NSTX-U which will integrate a non-inductive operation at reduced collisionality, long energy-confinement-times and a transition to a divertor solution with metal walls.

Design of tangential multi-energy SXR cameras for tokamak plasmas

NASA Astrophysics Data System (ADS)

Yamazaki, H.; Delgado-Aparicio, L. F.; Pablant, N.; Hill, K.; Bitter, M.; Takase, Y.; Ono, M.; Stratton, B.

2017-10-01

A new synthetic diagnostic capability has been built to study the response of tangential multi-energy soft x-ray pin-hole cameras for arbitrary plasma densities (ne , D), temperature (Te) and ion concentrations (nZ). For tokamaks and future facilities to operate safely in a high-pressure long-pulse discharge, it is imperative to address key issues associated with impurity sources, core transport and high-Z impurity accumulation. Multi-energy soft xray imaging provides a unique opportunity for measuring, simultaneously, a variety of important plasma properties (e.g. Te, nZ and ΔZeff). These systems are designed to sample the continuum- and line-emission from low- to high-Z impurities (e.g. C, O, Al, Si, Ar, Ca, Fe, Ni and Mo) in multiple energy-ranges. These x-ray cameras will be installed in the MST-RFP, as well as NSTX-U and DIII-D tokamaks, measuring the radial structure of the photon emissivity with a radial resolution below 1 cm at a 500 Hz frame rate and a photon-energy resolution of 500 eV. The layout and response expected for the new systems will be shown for different plasma conditions and impurity concentrations. The effect of toroidal rotation driving poloidal asymmetries in the core radiation is also addressed for the case of NSTX-U.

The changing role of accelerators in radiation therapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hanson, W.F.

Conventional low energy x-rays have been used in radiation therapy since the turn of the century. Van de Graaff and Betatron accelerators changed the complexion of radiation therapy in the mid 1940's by providing significantly deeper penetrating photon beams and also providing therapeutic quality electron beams. The development of Cobalt-60 teletherapy in the mid 1950's suppressed the role of accelerators in radiation therapy for nearly 20 years. However, with the development of reliable isocentric rotating linear accelerators, accelerators are rapidly becoming the most popular conventional therapy devices. Following unfavorable clinical results with fast neutron therapy in the late 1930's andmore » early 1940's, the role of cyclotron produced fast neutrons is presently experiencing a renewal in radiation therapy. Several facilities are also experimenting with heavy charged particle beams for therapy.« less

Firing of pulverized solvent refined coal

DOEpatents

Lennon, Dennis R.; Snedden, Richard B.; Foster, Edward P.; Bellas, George T.

1990-05-15

A burner for the firing of pulverized solvent refined coal is constructed and operated such that the solvent refined coal can be fired successfully without any performance limitations and without the coking of the solvent refined coal on the burner components. The burner is provided with a tangential inlet of primary air and pulverized fuel, a vaned diffusion swirler for the mixture of primary air and fuel, a center water-cooled conical diffuser shielding the incoming fuel from the heat radiation from the flame and deflecting the primary air and fuel steam into the secondary air, and a watercooled annulus located between the primary air and secondary air flows.

Vibrotactile Compliance Feedback for Tangential Force Interaction.

PubMed

Heo, Seongkook; Lee, Geehyuk

2017-01-01

This paper presents a method to generate a haptic illusion of compliance using a vibrotactile actuator when a tangential force is applied to a rigid surface. The novel method builds on a conceptual compliance model where a physical object moves on a textured surface in response to a tangential force. The method plays vibration patterns simulating friction-induced vibrations as an applied tangential force changes. We built a prototype consisting of a two-dimensional tangential force sensor and a surface transducer to test the effectiveness of the model. Participants in user experiments with the prototype perceived the rigid surface of the prototype as a moving, rubber-like plate. The main findings of the experiments are: 1) the perceived stiffness of a simulated material can be controlled by controlling the force-playback transfer function, 2) its perceptual properties such as softness and pleasantness can be controlled by changing friction grain parameters, and 3) the use of the vibrotactile compliance feedback reduces participants' workload including physical demand and frustration while performing a force repetition task.

Current advancement in radiation therapy for uterine cervical cancer.

PubMed

Nakano, Takashi; Ohno, Tatsuya; Ishikawa, Hitoshi; Suzuki, Yoshiyuki; Takahashi, Takeo

2010-01-01

Radiation therapy is one of the effective curative treatments for uterine cervical cancer. However poor clinical results for the advanced stages require further improvement of the treatment. Intensive studies on basic and clinical research have been made to improve local control, primarily important for long term survival in radiation therapy. Regarding current advancement in radiation therapy for uterine cervical cancer, the following three major subjects are pointed out; technological development to improve dose distribution by image guided radiation therapy technology, the concomitant anticancer chemotherapy with combination of radiation therapy, and radiation biological assessment of the radiation resistance of tumors. The biological factors overviewed in this article include hypoxia relating factors of HIF-1alpha, SOD, cell cycle parameters of pMI, proliferation factors of Ki67, EGFR, cerbB2, COX-2, cycle regulation proteins p53, p21, apoptosis regulation proteins Bcl2 and Bax and so on. Especially, the variety of these radiation biological factors is important for the selection of an effective treatment method for each patient to maximize the treatment benefit.

Obliquity dependence of the tangential YORP

NASA Astrophysics Data System (ADS)

Ševeček, P.; Golubov, O.; Scheeres, D. J.; Krugly, Yu. N.

2016-08-01

Context. The tangential Yarkovsky-O'Keefe-Radzievskii-Paddack (YORP) effect is a thermophysical effect that can alter the rotation rate of asteroids and is distinct from the so-called normal YORP effect, but to date has only been studied for asteroids with zero obliquity. Aims: We aim to study the tangential YORP force produced by spherical boulders on the surface of an asteroid with an arbitrary obliquity. Methods: A finite element method is used to simulate heat conductivity inside a boulder, to find the recoil force experienced by it. Then an ellipsoidal asteroid uniformly covered by these types of boulders is considered and the torque is numerically integrated over its surface. Results: Tangential YORP is found to operate on non-zero obliquities and decreases by a factor of two for increasing obliquity.

Airway complications after covered stent placement for malignant esophageal stricture: special reference to radiation therapy.

PubMed

Park, Ji Yeon; Shin, Ji Hoon; Song, Ho-Young; Yi, Seong Yoon; Kim, Jin Hyoung

2012-02-01

The purpose of this study was to evaluate the characteristics of airway complications and survival with special reference to radiation therapy in the care of patients undergoing covered stent placement for malignant esophageal strictures. A total of 208 patients who underwent stent placement with or without palliative radiation therapy for inoperable esophageal cancer were included. The endpoints were frequency, type, and management of airway complications; association between occurrence of airway complications and radiation therapy history; and differences in stent-to-complication interval and survival period after esophageal stenting between patients who underwent radiation therapy before and those who underwent radiation therapy after stent placement. Airway complications occurred in 23 patients (11.1%): 18 (78.3%) had esophagorespiratory fistula, three (13.0%) had airway narrowing, and two (8.7%) had both complications. The frequency of airway complications was significantly greater among patients who underwent RT than those who did not (p = 0.005) but was not significantly different between the radiation before stenting and radiation after stenting groups (p = 0.158). The median stent-to-complication interval and survival period after esophageal stenting were significantly shorter in the radiation before stenting group than in the radiation after stenting group (p = 0.002, p = 0.001). Esophagorespiratory fistula is much more common than airway narrowing as an airway complication. The rate of complications increases significantly in association with radiation therapy among patients with malignant esophageal stricture. Clinicians need to be aware of earlier airway complications and poorer prognosis among patients who undergo radiation therapy before placement of an esophageal stent than in patients who undergo radiation after stent placement.

Strategies for optimizing the response of cancer and normal tissues to radiation

PubMed Central

Moding, Everett J.; Kastan, Michael B.; Kirsch, David G.

2014-01-01

Approximately 50% of all patients with cancer receive radiation therapy at some point during the course of their treatment, and the majority of these patients are treated with curative intent. Despite recent advances in the planning of radiation treatment and the delivery of image-guided radiation therapy, acute toxicity and potential long-term side effects often limit the ability to deliver a sufficient dose of radiation to control tumours locally. In the past two decades, a better understanding of the hallmarks of cancer and the discovery of specific signalling pathways by which cells respond to radiation have provided new opportunities to design molecularly targeted therapies to increase the therapeutic window of radiation therapy. Here, we review efforts to develop approaches that could improve outcomes with radiation therapy by increasing the probability of tumour cure or by decreasing normal tissue toxicity. PMID:23812271

Use of Combination Thermal Therapy and Radiation in Breast-Conserving Treatment of Extensive Intraductal Breast Cancer

DTIC Science & Technology

1997-07-01

Review Board of the DFCI is provided in Appendix A . The investigator will keep the following information on each patient: 1. Past medical ...treatments, you will receive radiation therapy to your breast. Your radiation oncologist will decide what radiation dose you receive . On the basis of... Activities 6/87 Controversies in radiation therapy in

Internal Radiation Therapy for Cancer

Cancer.gov

When getting internal radiation therapy, a source of radiation is put inside your body, in either liquid or solid form. It can be used treat different kinds of cancer, including thyroid, head and neck, breast, cervix, prostate, and eye. Learn more about how what to expect when getting internal radiation therapy.

Optimization of Tangential Mass Injection for Minimizing Flow Separation in a Scramjet Inlet

DTIC Science & Technology

1991-12-01

34 Aerospace EnQineering, Vol. 11. No. 8, August 1991, p.23. 26. Heppenheimer , Thomas A . Lecture notes from Hypersonic Technologies seminar. University...AFIT/GAE/ENY,/9 lD-2 ( /~ AD-A243 868 "DTIC OPTIMIZATION OF TANGENTIAL MASS INJECTION FOR MINIMIZING FLOW SEPARATION IN A SC.R-.MJET INLET THESIS...OF TANGENTIAL MASS INJECTION FOR MINIMIZING FLOW SEPARATION IN A SCRAMJET INLEr THESIS Presented to the Faculty of the School of E.ngineering of the

Millimeter-wave detection using resonant tunnelling diodes

NASA Technical Reports Server (NTRS)

Mehdi, I.; Kidner, C.; East, J. R.; Haddad, G. I.

1990-01-01

A lattice-matched InGaAs/InAlAs resonant tunnelling diode is studied as a video detector in the millimeter-wave range. Tangential signal sensitivity and video resistance measurements are made as a function of bias and frequency. A tangential signal sensitivity of -37 dBm (1 MHz amplifier bandwidth) with a corresponding video resistance of 350 ohms at 40 GHz has been measured. These results appear to be the first millimeter-wave tangential signal sensitivity and video resistance results for a resonant tunnelling diode.

21 CFR 892.5770 - Powered radiation therapy patient support assembly.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Powered radiation therapy patient support assembly. 892.5770 Section 892.5770 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... therapy patient support assembly. (a) Identification. A powered radiation therapy patient support assembly...

21 CFR 892.5770 - Powered radiation therapy patient support assembly.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Powered radiation therapy patient support assembly. 892.5770 Section 892.5770 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... therapy patient support assembly. (a) Identification. A powered radiation therapy patient support assembly...

21 CFR 892.5770 - Powered radiation therapy patient support assembly.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Powered radiation therapy patient support assembly. 892.5770 Section 892.5770 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... therapy patient support assembly. (a) Identification. A powered radiation therapy patient support assembly...

21 CFR 892.5770 - Powered radiation therapy patient support assembly.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Powered radiation therapy patient support assembly. 892.5770 Section 892.5770 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... therapy patient support assembly. (a) Identification. A powered radiation therapy patient support assembly...

Radiation Therapy: Professions in Radiation Therapy

MedlinePlus

... and typically one to two years of clinical physics training. They are certified by the American Board of Radiology or the American Board of Medical Physics . Radiation Therapist Radiation therapists work with radiation oncologists. ...

Advances in prevention of radiation damage to visceral and solid organs in patients requiring radiation therapy of the trunk.

PubMed

Ritter, E F; Lee, C G; Tyler, D; Ferraro, F; Whiddon, C; Rudner, A M; Scully, S

1997-02-01

As a part of multimodality therapy, many patients with tumors of the trunk receive radiation therapy. The major morbidity of this therapy is often secondary to incidental radiation damage to tissues adjacent to treatment areas. We detail our use of saline breast implants placed in polyglycolic acid mesh sheets to displace visceral and solid organs away from the radiation field. Analysis of CT scans and dose volume histograms reveal that this technique successfully displaces uninvolved organs away from the radiation fields, thereby minimizing the radiation dose to such organs and tissues. We believe this is a safe and efficacious method to prevent radiation damage to visceral and solid organs adjacent to trunk tumor sites.

Effect of single dose radiation therapy on weight-bearing lameness in dogs with elbow osteoarthritis.

PubMed

Kapatkin, Amy S; Nordquist, Barbro; Garcia, Tanya C; Griffin, Maureen A; Theon, Alain; Kim, Sun; Hayashi, Kei

2016-07-19

To determine if a single low dose of radiation therapy in dogs with osteoarthritis of the elbow joint was associated with a detectable improvement in their lameness and pain as documented by force platform gait analysis. In this cohort longitudinal observational study, five Labrador Retrievers with lameness due to elbow osteoarthritis that was unresponsive to medical treatment were removed from all non-steroidal anti-inflammatory and analgesic medications. A single treatment of radiation therapy delivering 10 Gray was performed on the affected elbow joint(s). Force platform gait analysis was used to assess the ground reaction forces of a limb affected with elbow osteoarthritis both before and after radiation therapy. Significant differences occurred in the weight-bearing on an affected limb with elbow osteoarthritis after radiation therapy at weeks six and 14. Change due to treatment was particularly apparent in dogs with unilateral elbow osteoarthritis. Administering a single low dose of radiation therapy may have a short-term benefit in dogs with elbow osteoarthritis, which is similar to the evidence supporting the use of radiation therapy in horses with orthopaedic disease.

Reducing rectal injury in men receiving prostate cancer radiation therapy: current perspectives

PubMed Central

Serrano, Nicholas A; Kalman, Noah S; Anscher, Mitchell S

2017-01-01

Dose escalation is now the standard of care for the treatment of prostate cancer with radiation therapy. However, the rectum tends to be the dose-limiting structure when treating prostate cancer, given its close proximity. Early and late toxicities can occur when the rectum receives large doses of radiation therapy. New technologies allow for prevention of these toxicities. In this review, we examine the evidence that supports various dose constraints employed to prevent these rectal injuries from occurring. We also examine the use of intensity-modulated radiation therapy and how this compares to older radiation therapy techniques that allow for further sparing of the rectum during a radiation therapy course. We then review the literature on endorectal balloons and the effects of their daily use throughout a radiation therapy course. Tissue spacers are now being investigated in greater detail; these devices are injected into the rectoprostatic fascia to physically increase the distance between the prostate and the anterior rectal wall. Last, we review the use of systemic drugs, specifically statin medications and antihypertensives, as well as their impact on rectal toxicity. PMID:28814898

TH-F-202-03: Advances in MRI for Radiation Therapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cai, J.

MRI has excellent soft tissue contrast and can provide both anatomical and physiological information. It is becoming increasingly important in radiation therapy for treatment planning, image-guided radiation therapy, and treatment assessment. It is critically important at this time point to educate and update our medical physicists about MRI to prepare for the upcoming surge of MRI applications in radiation therapy. This session will review important basics of MR physics, pulse sequence designs, and current radiotherapy application, as well as showcase exciting new developments in MRI that can be potentially useful in radiation therapy. Learning Objectives: To learn basics of MRmore » physics and understand the differences between various pulse sequences To review current applications of MRI in radiation therapy.To discuss recent MRI advances for future MRI guided radiation therapy Partly supported by NIH (1R21CA165384).; W. Miller, Research supported in part by Siemens Healthcare; G. Li, My clinical research is in part supported by NIH U54CA137788. I have a collaborative research project with Philips Healthcare.; J. Cai, jing cai.« less

TH-F-202-00: MRI for Radiation Therapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

MRI has excellent soft tissue contrast and can provide both anatomical and physiological information. It is becoming increasingly important in radiation therapy for treatment planning, image-guided radiation therapy, and treatment assessment. It is critically important at this time point to educate and update our medical physicists about MRI to prepare for the upcoming surge of MRI applications in radiation therapy. This session will review important basics of MR physics, pulse sequence designs, and current radiotherapy application, as well as showcase exciting new developments in MRI that can be potentially useful in radiation therapy. Learning Objectives: To learn basics of MRmore » physics and understand the differences between various pulse sequences To review current applications of MRI in radiation therapy.To discuss recent MRI advances for future MRI guided radiation therapy Partly supported by NIH (1R21CA165384).; W. Miller, Research supported in part by Siemens Healthcare; G. Li, My clinical research is in part supported by NIH U54CA137788. I have a collaborative research project with Philips Healthcare.; J. Cai, jing cai.« less

Impact of partial versus whole breast radiation therapy on fatigue, perceived stress, quality of life and natural killer cell activity in women with breast cancer.

PubMed

Albuquerque, Kevin; Tell, Dina; Lobo, Philip; Millbrandt, Linda; Mathews, Herbert L; Janusek, Linda Witek

2012-06-18

This pilot study used a prospective longitudinal design to compare the effect of adjuvant whole breast radiation therapy (WBRT) versus partial breast radiation therapy (PBRT) on fatigue, perceived stress, quality of life and natural killer cell activity (NKCA) in women receiving radiation after breast cancer surgery. Women (N = 30) with early-stage breast cancer received either PBRT, Mammosite brachytherapy at dose of 34 Gy 10 fractions/5 days, (N = 15) or WBRT, 3-D conformal techniques at dose of 50 Gy +10 Gy Boost/30 fractions, (N = 15). Treatment was determined by the attending oncologist after discussion with the patient and the choice was based on tumor stage and clinical need. Women were assessed prior to initiation of radiation therapy and twice after completion of radiation therapy. At each assessment, blood was obtained for determination of NKCA and the following instruments were administered: Perceived Stress Scale (PSS), Functional Assessment of Cancer Therapy-Fatigue (FACT-F), and Functional Assessment of Cancer Therapy-General (FACT-G). Hierarchical linear modeling (HLM) was used to evaluate group differences in initial outcomes and change in outcomes over time. Fatigue (FACT-F) levels, which were similar prior to radiation therapy, demonstrated a significant difference in trajectory. Women who received PBRT reported progressively lower fatigue; conversely fatigue worsened over time for women who received WBRT. No difference in perceived stress was observed between women who received PBRT or WBRT. Both groups of women reported similar levels of quality of life (FACT-G) prior to initiation of radiation therapy. However, HLM analysis revealed significant group differences in the trajectory of quality of life, such that women receiving PBRT exhibited a linear increase in quality of life over time after completion of radiation therapy; whereas women receiving WBRT showed a decreasing trajectory. NKCA was also similar between therapy groups but additional post hoc analysis revealed that better quality of life significantly predicted higher NKCA regardless of therapy. Compared to WBRT, PBRT results in more rapid recovery from cancer-related fatigue with improved restoration of quality of life after radiation therapy. Additionally, better quality of life predicts higher NKCA against tumor targets, emphasizing the importance of fostering quality of life for women undergoing adjuvant radiation therapy.

Radiation therapy in early-stage invasive breast cancer.

PubMed

Lin, Ray; Tripuraneni, Prabhakar

2011-06-01

The treatment of breast cancer involves a multi-disciplinary approach with radiation therapy playing a key role. Breast-conserving surgery has been an option for women with early-stage breast cancer for over two decades now. Multiple randomized trials now have demonstrated the efficacy of breast-conserving surgery followed by radiation therapy. With the advancements in breast imaging and the successful campaign for early detection of breast cancer, more women today are found to have early-stage small breast cancers. Patient factors (breast size, tumor location, history of prior radiation therapy, preexisting conditions such as collagen vascular disease, age, having prosthetically augmented breasts), pathological factors (margin status, tumor size, presence of extensive intraductal component requiring multiple surgical excisions), as well as patient preference are all taken into consideration prior to surgical management of breast cancer. Whole-breast fractionated radiation therapy between 5 and 7 weeks is considered as the standard of care treatment following breast-conserving surgery. However, new radiation treatment strategies have been developed in recent years to provide alternatives to the conventional 5-7 week whole-breast radiation therapy for some patients. Accelerated partial breast radiation therapy (APBI) was introduced because the frequency of breast recurrences outside of the surgical cavity has been shown to be low. This technique allows treatments to be delivered quicker (usually 1 week, twice daily) to a limited volume. Often times, this treatment involves the use of a brachytherapy applicator to be placed into the surgical cavity following breast-conserving surgery. Accelerated hypofractionated whole-breast irradiation may be another faster way to deliver radiation therapy following breast-conserving surgery. This journal article reviews the role of radiation therapy in women with early-stage breast cancer addressing patient selection in breast-conserving therapy, a review of pertinent trials in breast-conserving therapy, as well as the different treatment techniques available to women following breast-conserving surgery.

Concurrent apatinib and local radiation therapy for advanced gastric cancer

PubMed Central

Zhang, Ming; Deng, Weiye; Cao, Xiaoci; Shi, Xiaoming; Zhao, Huanfen; Duan, Zheping; Lv, Bonan; Liu, Bin

2017-01-01

Abstract Rationale: Apatinib is a novel anti-angiogenic agent targeting vascular endothelial growth factor receptor-2, which is effective in patients with chemotherapy-refractory gastric cancer. There are no reports of concurrent apatinib with local radiation therapy in elderly patients with advanced gastric cancer. Patient concerns and Diagnoses: we present the first published report of a 70-year-old male patient with advanced gastric cancer who received concurrent apatinib and local radiation therapy after failure of oxaliplatin and S-1 chemotherapy. Interventions and Outcomes: The patient received concurrent apatinib and local radiation therapy and was followed up 7 months after therapy without disease progress, 14 months later indicated extensive metastasis and this patient died of pulmonary infection. Lessons: Elderly patients with advanced gastric cancer may benefit from concurrent apatinib with local radiation therapy when chemotherapy is not tolerated or successful. Further studies are needed to investigate the clinical outcomes and toxicities associated with concurrent apatinib and radiation therapy in gastric cancer. PMID:28248891

Concurrent apatinib and local radiation therapy for advanced gastric cancer: A case report and review of the literature.

PubMed

Zhang, Ming; Deng, Weiye; Cao, Xiaoci; Shi, Xiaoming; Zhao, Huanfen; Duan, Zheping; Lv, Bonan; Liu, Bin

2017-03-01

Apatinib is a novel anti-angiogenic agent targeting vascular endothelial growth factor receptor-2, which is effective in patients with chemotherapy-refractory gastric cancer. There are no reports of concurrent apatinib with local radiation therapy in elderly patients with advanced gastric cancer. PATIENT CONCERNS AND DIAGNOSES:: we present the first published report of a 70-year-old male patient with advanced gastric cancer who received concurrent apatinib and local radiation therapy after failure of oxaliplatin and S-1 chemotherapy. The patient received concurrent apatinib and local radiation therapy and was followed up 7 months after therapy without disease progress, 14 months later indicated extensive metastasis and this patient died of pulmonary infection. Elderly patients with advanced gastric cancer may benefit from concurrent apatinib with local radiation therapy when chemotherapy is not tolerated or successful. Further studies are needed to investigate the clinical outcomes and toxicities associated with concurrent apatinib and radiation therapy in gastric cancer.

The concept and evolution of involved site radiation therapy for lymphoma.

PubMed

Specht, Lena; Yahalom, Joachim

2015-10-01

We describe the development of radiation therapy for lymphoma from extended field radiotherapy of the past to modern conformal treatment with involved site radiation therapy based on advanced imaging, three-dimensional treatment planning and advanced treatment delivery techniques. Today, radiation therapy is part of the multimodality treatment of lymphoma, and the irradiated tissue volume is much smaller than before, leading to highly significant reductions in the risks of long-term complications.

Enhancement of Radiation Therapy in Prostate Cancer by DNA-PKcs Inhibitor

DTIC Science & Technology

2012-07-01

Award Number: W81XWH-11-1-0270 TITLE: Enhancement of Radiation Therapy in Prostate Cancer by DNA-PKcs Inhibitor PRINCIPAL INVESTIGATOR...TITLE AND SUBTITLE Enhancement of Radiation Therapy in Prostate Cancer by 5a. CONTRACT NUMBER DNA-PKcs Inhibitor 5b. GRANT NUMBER W81XWH-11-1-0270...the treatment of localized prostate cancer . However, a proportion of locally advanced cancers develop radiation resistance and recur after therapy

Tangential migration of glutamatergic neurons and cortical patterning during development: Lessons from Cajal-Retzius cells.

PubMed

Barber, Melissa; Pierani, Alessandra

2016-08-01

Tangential migration is a mode of cell movement, which in the developing cerebral cortex, is defined by displacement parallel to the ventricular surface and orthogonal to the radial glial fibers. This mode of long-range migration is a strategy by which distinct neuronal classes generated from spatially and molecularly distinct origins can integrate to form appropriate neural circuits within the cortical plate. While it was previously believed that only GABAergic cortical interneurons migrate tangentially from their origins in the subpallial ganglionic eminences to integrate in the cortical plate, it is now known that transient populations of glutamatergic neurons also adopt this mode of migration. These include Cajal-Retzius cells (CRs), subplate neurons (SPs), and cortical plate transient neurons (CPTs), which have crucial roles in orchestrating the radial and tangential development of the embryonic cerebral cortex in a noncell-autonomous manner. While CRs have been extensively studied, it is only in the last decade that the molecular mechanisms governing their tangential migration have begun to be elucidated. To date, the mechanisms of SPs and CPTs tangential migration remain unknown. We therefore review the known signaling pathways, which regulate parameters of CRs migration including their motility, contact-redistribution and adhesion to the pial surface, and discuss this in the context of how CR migration may regulate their signaling activity in a spatial and temporal manner. © 2015 Wiley Periodicals, Inc. Develop Neurobiol 76: 847-881, 2016. © 2015 Wiley Periodicals, Inc.

Radiation therapy facilities in the United States

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ballas, Leslie K.; Elkin, Elena B.; Schrag, Deborah

2006-11-15

Purpose: About half of all cancer patients in the United States receive radiation therapy as a part of their cancer treatment. Little is known, however, about the facilities that currently deliver external beam radiation. Our goal was to construct a comprehensive database of all radiation therapy facilities in the United States that can be used for future health services research in radiation oncology. Methods and Materials: From each state's health department we obtained a list of all facilities that have a linear accelerator or provide radiation therapy. We merged these state lists with information from the American Hospital Association (AHA),more » as well as 2 organizations that audit the accuracy of radiation machines: the Radiologic Physics Center (RPC) and Radiation Dosimetry Services (RDS). The comprehensive database included all unique facilities listed in 1 or more of the 4 sources. Results: We identified 2,246 radiation therapy facilities operating in the United States as of 2004-2005. Of these, 448 (20%) facilities were identified through state health department records alone and were not listed in any other data source. Conclusions: Determining the location of the 2,246 radiation facilities in the United States is a first step in providing important information to radiation oncologists and policymakers concerned with access to radiation therapy services, the distribution of health care resources, and the quality of cancer care.« less

Dosimetry and field matching for radiotherapy to the breast and superclavicular fossa

NASA Astrophysics Data System (ADS)

Winfield, Elizabeth

Radiotherapy for early breast cancer aims to achieve local disease control and decrease loco-regional recurrence rates. Treatment may be directed to breast or chest wall alone or, include regional lymph nodes. When using tangential fields to treat the breast a separate anterior field directed to the axilla and supraclavicular fossa (SCF) is needed to treat nodal areas. The complex geometry of this region necessitates matching of adjacent radiation fields in three dimensions. The potential exists for zones of overdosage or underdosage along the match line. Cosmetic results may be compromised if treatment fields are not accurately aligned. Techniques for field matching vary between centres in the UK. A study of dosimetry across the match line region using different techniques, as reported in the multi-centre START Trial Quality Assurance (QA) programme, was undertaken. A custom-made anthropomorphic phantom was designed to assess dose distribution in three dimensions using film dosimetry. Methods with varying degrees of complexity were employed to match tangential and SCF beams. Various techniques combined half beam blocking and machine rotations to achieve geometric alignment. Matching of asymmetric beams allowed a single isocentre technique to be used. Where field matching was not undertaken a gap between tangential and SCF fields was employed. Results demonstrated differences between techniques in addition to variations within the same technique between different centres. Geometric alignment techniques produced more homogenous dose distributions in the match region than gap techniques or those techniques not correcting for field divergence. For this multi-centre assessment of match plane techniques film dosimetry used in conjunction with a breast shaped phantom provided relative dose information. This study has highlighted the difficulties of matching treatment fields to achieve homogenous dose distribution through the region of the match plane and the degree of inhomogeneity as a consequence of a gap between treatment fields.

Computed Tomography Density Change in the Thyroid Gland Before and After Radiation Therapy.

PubMed

Ishibashi, Naoya; Maebayashi, Toshiya; Aizawa, Takuya; Sakaguchi, Masakuni; Okada, Masahiro; Matsushita, Junichi

2018-01-01

Hypothyroidism is an established adverse effect of radiation therapy for head and neck cancer, and computed tomography (CT) density of the thyroid gland is lower in hypothyroid than euthyroid individuals. No previous studies have evaluated changes in CT densities of the thyroid gland caused by radiation therapy. The aim was to investigate the relationship between the change in CT density of the thyroid gland before and after radiation therapy for head and neck cancer and hypothyroidism. This retrospective study analyzed data of 24 patients treated by radiation therapy for head and neck cancers. After dosimetric analysis of received radiation therapy, a Picture Archiving and Communication System was used to manually contour the thyroid on pre-treatment CT images to enable determination of mean thyroid gland CT densities and received radiation doses. Pre- and post-treatment thyroid function was assessed on the basis of serum TSH concentrations. Multivariate and univariate analyses were used to determine what clinical factors are associated with post-radiation therapy decrease in CT density of the thyroid and Pearson's χ 2 test was used to assess correlations between these densities and TSH concentrations. Mean CT densities of the thyroid gland decreased from before to after radiation therapy in 73.9% of our patients (median decrease 16.8 HU). Serum TSH concentrations were significantly higher in patients with greater then median decreases in CT density than in those with lesser or no decreases. Post-radiation therapy hypothyroidism may be predicted by significant decreases in CT density of the thyroid gland. Copyright© 2018, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

Stage III Melanoma in the Axilla: Patterns of Regional Recurrence After Surgery With and Without Adjuvant Radiation Therapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pinkham, Mark B., E-mail: mark.pinkham@health.qld.gov.au; University of Queensland, Brisbane; Foote, Matthew C.

Purpose: To describe the anatomic distribution of regionally recurrent disease in patients with stage III melanoma in the axilla after curative-intent surgery with and without adjuvant radiation therapy. Methods and Materials: A single-institution, retrospective analysis of a prospective database of 277 patients undergoing curative-intent treatment for stage III melanoma in the axilla between 1992 and 2012 was completed. For patients who received radiation therapy and those who did not, patterns of regional recurrence were analyzed, and univariate analyses were performed to assess for potential factors associated with location of recurrence. Results: There were 121 patients who received adjuvant radiation therapymore » because their clinicopathologic features conferred a greater risk of regional recurrence. There were 156 patients who received no radiation therapy. The overall axillary control rate was 87%. There were 37 patients with regional recurrence; 17 patients had received adjuvant radiation therapy (14%), and 20 patients (13%) had not. The likelihood of in-field nodal recurrence was significantly less in the adjuvant radiation therapy group (P=.01) and significantly greater in sites adjacent to the axilla (P=.02). Patients with high-risk clinicopathologic features who did not receive adjuvant radiation therapy also tended to experience in-field failure rather than adjacent-field failure. Conclusions: Patients who received adjuvant radiation therapy were more likely to experience recurrence in the adjacent-field regions rather than in the in-field regions. This may not simply reflect higher-risk pathology. Using this data, it may be possible to improve outcomes by reducing the number of adjacent-field recurrences after adjuvant radiation therapy.« less

The adoption of new adjuvant radiation therapy modalities among Medicare beneficiaries with breast cancer: clinical correlates and cost implications.

PubMed

Roberts, Kenneth B; Soulos, Pamela R; Herrin, Jeph; Yu, James B; Long, Jessica B; Dostaler, Edward; Gross, Cary P

2013-04-01

New radiation therapy modalities have broadened treatment options for older women with breast cancer, but it is unclear how clinical factors, geographic region, and physician preference affect the choice of radiation therapy modality. We used the Surveillance, Epidemiology, and End Results-Medicare database to identify women diagnosed with stage I-III breast cancer from 1998 to 2007 who underwent breast-conserving surgery. We assessed the temporal trends in, and costs of, the adoption of intensity modulated radiation therapy (IMRT) and brachytherapy. Using hierarchical logistic regression, we evaluated the relationship between the use of these new modalities and patient and regional characteristics. Of 35,060 patients, 69.9% received conventional external beam radiation therapy (EBRT). Although overall radiation therapy use remained constant, the use of IMRT increased from 0.0% to 12.6% from 1998 to 2007, and brachytherapy increased from 0.7% to 9.0%. The statistical variation in brachytherapy use attributable to the radiation oncologist and geographic region was 41.4% and 9.5%, respectively (for IMRT: 23.8% and 22.1%, respectively). Women undergoing treatment at a free-standing radiation facility were significantly more likely to receive IMRT than were women treated at a hospital-based facility (odds ratio for IMRT vs EBRT: 3.89 [95% confidence interval, 2.78-5.45]). No such association was seen for brachytherapy. The median radiation therapy cost per treated patient increased from $5389 in 2001 to $8539 in 2007. IMRT and brachytherapy use increased substantially from 1998 to 2007; overall, radiation therapy costs increased by more than 50%. Radiation oncologists played an important role in treatment choice for both types of radiation therapy, whereas geographic region played a bigger role in the use of IMRT than brachytherapy. Copyright © 2013 Elsevier Inc. All rights reserved.

The Adoption of New Adjuvant Radiation Therapy Modalities Among Medicare Beneficiaries With Breast Cancer: Clinical Correlates and Cost Implications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Roberts, Kenneth B.; Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, Connecticut; Soulos, Pamela R.

2013-04-01

Purpose: New radiation therapy modalities have broadened treatment options for older women with breast cancer, but it is unclear how clinical factors, geographic region, and physician preference affect the choice of radiation therapy modality. Methods and Materials: We used the Surveillance, Epidemiology, and End Results-Medicare database to identify women diagnosed with stage I-III breast cancer from 1998 to 2007 who underwent breast-conserving surgery. We assessed the temporal trends in, and costs of, the adoption of intensity modulated radiation therapy (IMRT) and brachytherapy. Using hierarchical logistic regression, we evaluated the relationship between the use of these new modalities and patient andmore » regional characteristics. Results: Of 35,060 patients, 69.9% received conventional external beam radiation therapy (EBRT). Although overall radiation therapy use remained constant, the use of IMRT increased from 0.0% to 12.6% from 1998 to 2007, and brachytherapy increased from 0.7% to 9.0%. The statistical variation in brachytherapy use attributable to the radiation oncologist and geographic region was 41.4% and 9.5%, respectively (for IMRT: 23.8% and 22.1%, respectively). Women undergoing treatment at a free-standing radiation facility were significantly more likely to receive IMRT than were women treated at a hospital-based facility (odds ratio for IMRT vs EBRT: 3.89 [95% confidence interval, 2.78-5.45]). No such association was seen for brachytherapy. The median radiation therapy cost per treated patient increased from $5389 in 2001 to $8539 in 2007. Conclusions: IMRT and brachytherapy use increased substantially from 1998 to 2007; overall, radiation therapy costs increased by more than 50%. Radiation oncologists played an important role in treatment choice for both types of radiation therapy, whereas geographic region played a bigger role in the use of IMRT than brachytherapy.« less

[The results of strontium-90 contact therapy to prevent the recurrence of pterygium].

PubMed

Schultze, J; Hinrichs, M; Kimmig, B

1996-08-01

Aim of the study was the evaluation of the role of adjuvant radiation therapy in the prevention of recurrence after excision. Between July 1, 1985 and April 1, 1993, 64 patients (43 male, 21 female) were referred to radiation therapy after excision of a nasal pterygium. Radiation therapy was done with a strontium-90 eye applicator and a total dose of 30 Gy, fractionated in 6 fractions of 5 Gy each, 3 times a week. Forty-nine patients were treated primarily, 15 patients underwent radiation therapy for the first time in case of recurrent pterygium after multiple re-excisions. All patients had a following of 1 to 9 years with a median of 5.5 years. In 8 of 64 irradiated patients recurrent pterygium was detected (12.5%). Differentiated into the 2 groups 4 of the primarily treated patients had recurrent pterygium (8.16%), the other 4 were in the group with multiple former re-excisions (26.7%). With regard to the initiation of the irradiation after surgery pterygium did not recur in any of the primarily treated patients who were irradiated in between 3 days after surgery. In contrary 3 of 7 primarily treated patients (42.9%) who started radiation therapy between 7 and 10 days after surgery had recurrent pterygium. For the patients with primarily recurrent pterygium no dependence of the initiation of radiation therapy after surgery could be detected. Adjuvant radiation therapy after excision of pterygium lowers the rate of recurrence from about 40% to 12.5%, in a primarily adjuvant situation to 8.16%. In these patients radiation therapy should be initiated within 3 days after surgery. Patients with primarily recurrent pterygium have an elevated risk of recurrence independently of the initiation of radiation therapy.

RADIATION THERAPY COMMUNICATION-REIRRADIATION OF A NASAL TUMOR IN A BRACHYCEPHALIC DOG USING INTENSITY MODULATED RADIATION THERAPY.

PubMed

Rancilio, Nicholas J; Custead, Michelle R; Poulson, Jean M

2016-09-01

A 5-year-old spayed female Shih Tzu was referred for evaluation of a nasal transitional carcinoma. A total lifetime dose of 117 Gy was delivered to the intranasal mass in three courses over nearly 2 years using fractionated intensity modulated radiation therapy (IMRT) to spare normal tissues. Clinically significant late normal tissue side effects were limited to bilaterally diminished tear production. The patient died of metastatic disease progression 694 days after completion of radiation therapy course 1. This case demonstrates that retreatment with radiation therapy to high lifetime doses for recurrent local disease may be well tolerated with IMRT. © 2016 American College of Veterinary Radiology.

Axillary irradiation omitting axillary dissection in breast cancer: is there a role for shoulder-sparing proton therapy?

PubMed Central

Deidda, M A; Amichetti, M

2015-01-01

The recent EORTC 10981-22023 AMAROS trial showed that axillary radiotherapy and axillary lymph node dissection provide comparable local control and reduced lymphoedema in the irradiated group. However, no significant differences between the two groups in range of motion and quality of life were reported. It has been acknowledged that axillary irradiation could have induced some toxicity, particularly shoulder function impairment. In fact, conventional breast irradiation by tangential beams has to be modified to achieve full-dose coverage of the axillary nodes, including in the treatment field a larger portion of the shoulder structures. In this scenario, alternative irradiation techniques were discussed. Compared with modern photon techniques, axillary irradiation by proton therapy has the potential for sparing the shoulder without detrimental increase of the medium-to-low doses to the other normal tissues. PMID:26153903

Recent advances in radiation cancer therapy

NASA Astrophysics Data System (ADS)

Ma, C.-M. Charlie

2007-03-01

This paper presents the recent advances in radiation therapy techniques for the treatment of cancer. Significant improvement has been made in imaging techniques such as CT, MRI, MRS, PET, ultrasound, etc. that have brought marked advances in tumor target and critical structure delineation for treatment planning and patient setup and target localization for accurate dose delivery in radiation therapy of cancer. Recent developments of novel treatment modalities including intensity-modulated x-ray therapy (IMXT), energy- and intensity modulated electron therapy (MERT) and intensity modulated proton therapy (IMPT) together with the use of advanced image guidance have enabled precise dose delivery for dose escalation and hypofractionation studies that may result in better local control and quality of life. Particle acceleration using laser-induced plasmas has great potential for new cost-effective radiation sources that may have a great impact on the management of cancer using radiation therapy.

Dose and Fractionation in Radiation Therapy of Curative Intent for Non-Small Cell Lung Cancer: Meta-Analysis of Randomized Trials

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ramroth, Johanna; Cutter, David J.; Darby, Sarah C.

Purpose: The optimum dose and fractionation in radiation therapy of curative intent for non-small cell lung cancer remains uncertain. We undertook a published data meta-analysis of randomized trials to examine whether radiation therapy regimens with higher time-corrected biologically equivalent doses resulted in longer survival, either when given alone or when given with chemotherapy. Methods and Materials: Eligible studies were randomized comparisons of 2 or more radiation therapy regimens, with other treatments identical. Median survival ratios were calculated for each comparison and pooled. Results: 3795 patients in 25 randomized comparisons of radiation therapy dose were studied. The median survival ratio, highermore » versus lower corrected dose, was 1.13 (95% confidence interval [CI] 1.04-1.22) when radiation therapy was given alone and 0.83 (95% CI 0.71-0.97) when it was given with concurrent chemotherapy (P for difference=.001). In comparisons of radiation therapy given alone, the survival benefit increased with increasing dose difference between randomized treatment arms (P for trend=.004). The benefit increased with increasing dose in the lower-dose arm (P for trend=.01) without reaching a level beyond which no further survival benefit was achieved. The survival benefit did not differ significantly between randomized comparisons where the higher-dose arm was hyperfractionated and those where it was not. There was heterogeneity in the median survival ratio by geographic region (P<.001), average age at randomization (P<.001), and year trial started (P for trend=.004), but not for proportion of patients with squamous cell carcinoma (P=.2). Conclusions: In trials with concurrent chemotherapy, higher radiation therapy doses resulted in poorer survival, possibly caused, at least in part, by high levels of toxicity. Where radiation therapy was given without chemotherapy, progressively higher radiation therapy doses resulted in progressively longer survival, and no upper dose level was found above which there was no further benefit. These findings support the consideration of further radiation therapy dose escalation trials, making use of modern treatment methods to reduce toxicity.« less

Advances in radiotherapy techniques and delivery for non-small cell lung cancer: benefits of intensity-modulated radiation therapy, proton therapy, and stereotactic body radiation therapy

PubMed Central

Diwanji, Tejan P.; Mohindra, Pranshu; Vyfhuis, Melissa; Snider, James W.; Kalavagunta, Chaitanya; Mossahebi, Sina; Yu, Jen; Feigenberg, Steven

2017-01-01

The 21st century has seen several paradigm shifts in the treatment of non-small cell lung cancer (NSCLC) in early-stage inoperable disease, definitive locally advanced disease, and the postoperative setting. A key driver in improvement of local disease control has been the significant evolution of radiation therapy techniques in the last three decades, allowing for delivery of definitive radiation doses while limiting exposure of normal tissues. For patients with locally-advanced NSCLC, the advent of volumetric imaging techniques has allowed a shift from 2-dimensional approaches to 3-dimensional conformal radiation therapy (3DCRT). The next generation of 3DCRT, intensity-modulated radiation therapy and volumetric-modulated arc therapy (VMAT), have enabled even more conformal radiation delivery. Clinical evidence has shown that this can improve the quality of life for patients undergoing definitive management of lung cancer. In the early-stage setting, conventional fractionation led to poor outcomes. Evaluation of altered dose fractionation with the previously noted technology advances led to advent of stereotactic body radiation therapy (SBRT). This technique has dramatically improved local control and expanded treatment options for inoperable, early-stage patients. The recent development of proton therapy has opened new avenues for improving conformity and the therapeutic ratio. Evolution of newer proton therapy techniques, such as pencil-beam scanning (PBS), could improve tolerability and possibly allow reexamination of dose escalation. These new progresses, along with significant advances in systemic therapies, have improved survival for lung cancer patients across the spectrum of non-metastatic disease. They have also brought to light new challenges and avenues for further research and improvement. PMID:28529896

Whole breast radiation therapy

MedlinePlus

... 11, 2016. www.cancer.gov/types/breast/hp/breast-treatment-pdq . Accessed September 13, 2016. National Cancer Institute. Radiation therapy and you: support for people who have cancer. Cancer.gov Web site. www.cancer.gov/publications/patient-education/radiation-therapy-and-you . Accessed September 13, ...

Whole-Pelvic Nodal Radiation Therapy in the Context of Hypofractionation for High-Risk Prostate Cancer Patients: A Step Forward

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kaidar-Person, Orit; Roach, Mack; Créhange, Gilles, E-mail: gcrehange@cgfl.fr

2013-07-15

Given the low α/β ratio of prostate cancer, prostate hypofractionation has been tested through numerous clinical studies. There is a growing body of literature suggesting that with high conformal radiation therapy and even with more sophisticated radiation techniques, such as high-dose-rate brachytherapy or image-guided intensity modulated radiation therapy, morbidity associated with shortening overall treatment time with higher doses per fraction remains low when compared with protracted conventional radiation therapy to the prostate only. In high-risk prostate cancer patients, there is accumulating evidence that either dose escalation to the prostate or hypofractionation may improve outcome. Nevertheless, selected patients who have amore » high risk of lymph node involvement may benefit from whole-pelvic radiation therapy (WPRT). Although combining WPRT with hypofractionated prostate radiation therapy is feasible, it remains investigational. By combining modern advances in radiation oncology (high-dose-rate prostate brachytherapy, intensity modulated radiation therapy with an improved image guidance for soft-tissue sparing), it is hypothesized that WPRT could take advantage of recent results from hypofractionation trials. Moreover, the results from hypofractionation trials raise questions as to whether hypofractionation to pelvic lymph nodes with a high risk of occult involvement might improve the outcomes in WPRT. Although investigational, this review discusses the challenging idea of WPRT in the context of hypofractionation for patients with high-risk prostate cancer.« less

Outcomes of Pediatric Low-grade Gliomas Treated With Radiation Therapy: A Single-institution Study

PubMed Central

Raikar, Sunil S.; Halloran, Donna R.; Elliot, Michael; McHugh, Michele; Patel, Shaun; Gauvain, Karen M.

2014-01-01

Summary Radiation therapy is often considered the treatment of choice for low-grade gliomas. However, given the long-term effects of radiation on the developing brain, the appropriate use of radiation therapy in pediatric patients remains controversial. The purpose of this study was to evaluate progression-free survival (PFS) of pediatric low-grade glioma patients treated with radiation therapy. Data were obtained through a retrospective chart review of patients treated between 1991 and 2008 from a single tertiary care center in the midwest. The study population consisted of 17 patients, of whom 8 (47%) had tumor recurrence after radiation therapy. The median follow-up time was 8.2 years, with a range of 2.3 to 17.2 years. The median age at diagnosis was 5.4 years, and the median age at radiation therapy was 9.4 years. The 3- and the 10-year PFS were 69% ± 11.7% and 46% ± 13.3%, respectively. A significant difference in PFS was seen when comparing brainstem tumors with hypothalamic/optic pathway tumors (P = 0.019). Differences in PFS based on the age at diagnosis, the extent of initial surgery, and indication for radiation therapy were not significant. A larger multicenter study is needed to better assess PFS in these patients. PMID:24714505

Expanding the use of real-time electromagnetic tracking in radiation oncology.

PubMed

Shah, Amish P; Kupelian, Patrick A; Willoughby, Twyla R; Meeks, Sanford L

2011-11-15

In the past 10 years, techniques to improve radiotherapy delivery, such as intensity-modulated radiation therapy (IMRT), image-guided radiation therapy (IGRT) for both inter- and intrafraction tumor localization, and hypofractionated delivery techniques such as stereotactic body radiation therapy (SBRT), have evolved tremendously. This review article focuses on only one part of that evolution, electromagnetic tracking in radiation therapy. Electromagnetic tracking is still a growing technology in radiation oncology and, as such, the clinical applications are limited, the expense is high, and the reimbursement is insufficient to cover these costs. At the same time, current experience with electromagnetic tracking applied to various clinical tumor sites indicates that the potential benefits of electromagnetic tracking could be significant for patients receiving radiation therapy. Daily use of these tracking systems is minimally invasive and delivers no additional ionizing radiation to the patient, and these systems can provide explicit tumor motion data. Although there are a number of technical and fiscal issues that need to be addressed, electromagnetic tracking systems are expected to play a continued role in improving the precision of radiation delivery.

Expanding the use of real‐time electromagnetic tracking in radiation oncology

PubMed Central

Kupelian, Patrick A.; Willoughby, Twyla R.; Meeks, Sanford L.

2011-01-01

In the past 10 years, techniques to improve radiotherapy delivery, such as intensity‐modulated radiation therapy (IMRT), image‐guided radiation therapy (IGRT) for both inter‐ and intrafraction tumor localization, and hypofractionated delivery techniques such as stereotactic body radiation therapy (SBRT), have evolved tremendously. This review article focuses on only one part of that evolution, electromagnetic tracking in radiation therapy. Electromagnetic tracking is still a growing technology in radiation oncology and, as such, the clinical applications are limited, the expense is high, and the reimbursement is insufficient to cover these costs. At the same time, current experience with electromagnetic tracking applied to various clinical tumor sites indicates that the potential benefits of electromagnetic tracking could be significant for patients receiving radiation therapy. Daily use of these tracking systems is minimally invasive and delivers no additional ionizing radiation to the patient, and these systems can provide explicit tumor motion data. Although there are a number of technical and fiscal issues that need to be addressed, electromagnetic tracking systems are expected to play a continued role in improving the precision of radiation delivery. PACS number: 87.63.‐d PMID:22089017

Three Dimensional Solution of Pneumatic Active Control of Forebody Vortex Asymmetry

NASA Technical Reports Server (NTRS)

Kandil, Osama A.; SharafEl-Din, Hazem H.; Liu, C. H.

1995-01-01

Pneumatic active control of asymmetric vortical flows around a slender pointed forebody is investigated using the three dimensional solution for the compressible thin-layer Navier-Stokes equation. The computational applications cover the normal and tangential injection control of asymmetric flows around a 5 degree semi-apex angle cone at a 40 degree angle of attack, 1.4 freestream Mach number and 6 x 10(exp 6) freestream Reynolds number (based on the cone length). The effective tangential angle range of 67.5 approaches minus 67.5 degrees is used for both normal and tangential ports of injection. The effective axial length of injection is varied from 0.03 to 0.05. The computational solver uses the implicit, upwind, flux difference splitting finite volume scheme, and the grid consists of 161 x 55 x 65 points in the wrap around, normal and axial directions, respectively. The results show that tangential injection is more effective than normal injection.

Influences of rolling method on deformation force in cold roll-beating forming process

NASA Astrophysics Data System (ADS)

Su, Yongxiang; Cui, Fengkui; Liang, Xiaoming; Li, Yan

2018-03-01

In process, the research object, the gear rack was selected to study the influence law of rolling method on the deformation force. By the mean of the cold roll forming finite element simulation, the variation regularity of radial and tangential deformation was analysed under different rolling methods. The variation of deformation force of the complete forming racks and the single roll during the steady state under different rolling modes was analyzed. The results show: when upbeating and down beating, radial single point average force is similar, the tangential single point average force gap is bigger, the gap of tangential single point average force is relatively large. Add itionally, the tangential force at the time of direct beating is large, and the dire ction is opposite with down beating. With directly beating, deformation force loading fast and uninstall slow. Correspondingly, with down beating, deformat ion force loading slow and uninstall fast.

Forebody tangential blowing for control at high angles of attack

NASA Technical Reports Server (NTRS)

Kroo, I.; Rock, S.; Roberts, L.

1991-01-01

A feasibility study to determine if the use of tangential leading edge blowing over the forebody could produce effective and practical control of the F-18 HARV aircraft at high angles of attack was conducted. A simplified model of the F-18 configuration using a vortex-lattice model was developed to obtain a better understanding of basic aerodynamic coupling effects and the influence of forebody circulation on lifting surface behavior. The effect of tangential blowing was estimated using existing wind tunnel data on normal forebody blowing and analytical studies of tangential blowing over conical forebodies. Incorporation of forebody blowing into the flight control system was investigated by adding this additional yaw control and sideforce generating actuator into the existing F-18 HARV simulation model. A control law was synthesized using LQG design methods that would schedule blowing rates as a function of vehicle sideslip, angle of attack, and roll and yaw rates.

21 CFR 1020.32 - Fluoroscopic equipment.

Code of Federal Regulations, 2010 CFR

2010-04-01

.... Radiation therapy simulation systems shall be exempt from this requirement provided the systems are intended... 10, 2006, other than radiation therapy simulation systems, the following applies: (A) Neither the... fluoroscopic equipment manufactured on or after June 10, 2006, other than radiation therapy simulation systems...

Radiation Therapy Did Not Induce Long-Term Changes in Rectal Mucosa: Results From the Randomized Scandinavian Prostate Cancer Group 7 Trial

DOE Office of Scientific and Technical Information (OSTI.GOV)

Slagsvold, Jens Erik, E-mail: Jens.Erik.Slagsvold@stolav.no; Viset, Trond; Wibe, Arne

Purpose: To investigate long-term changes in the rectal mucosa after curative external beam radiation therapy in the treatment of prostate cancer. Methods and Materials: In the Scandinavian Prostate Cancer Group 7 trial, 880 men with locally advanced prostate cancer were randomized to hormonal therapy alone versus hormonal therapy plus radiation therapy to 70 Gy. A subcohort from this trial being randomized at our center (n=178) was invited to a study on late anorectal side effects during 2003-2005, approximately 5 years after treatment, including measuring health-reported quality of life and physician-assessed toxicity score by the Late Effects Normal Tissue Task Force/Subjective, Objective, Management, Analyticmore » (LENT/SOMA) and European Organization for Research and Treatment of Cancer/Radiation Therapy Oncology Group score. Sixty-seven patients had a rectal mucosa biopsy. Sixty-four biopsies were included in the final analysis, of which 33 patients were randomized to hormonal treatment and 31 to hormonal treatment plus radiation therapy. The presence of fibrosis, number of capillaries, and lymphocyte infiltration was then evaluated by light microscopy. Results: The group receiving radiation therapy had significantly higher LENT/SOMA and function/bother scale scores than the group that only received hormonal treatment, but there was no significant difference in the presence of fibrosis, ectasia, number of capillaries in the lamina propria, or lymphocyte infiltration between the groups. Conclusion: Radiation therapy to 70 Gy to the prostate does not induce long-term microscopic mucosal changes in the rectum 5 years after treatment. This is in contrast to the general assumption that structural changes, including fibrosis, seen after radiation therapy include the mucosa. We speculate that the main late effects of radiation therapy on the structure of the rectum are located in the deeper layers of the rectal wall than the mucosa.« less

Appropriate customization of radiation therapy for stage II and III rectal cancer: Executive summary of an ASTRO Clinical Practice Statement using the RAND/UCLA Appropriateness Method.

PubMed

Goodman, Karyn A; Patton, Caroline E; Fisher, George A; Hoffe, Sarah E; Haddock, Michael G; Parikh, Parag J; Kim, John; Baxter, Nancy N; Czito, Brian G; Hong, Theodore S; Herman, Joseph M; Crane, Christopher H; Hoffman, Karen E

2016-01-01

To summarize results of a Clinical Practice Statement on radiation therapy for stage II-III rectal cancer, which addressed appropriate customization of (neo)adjuvant radiation therapy and use of non-surgical therapy for patients who are inoperable or refuse abdominoperineal resection. The RAND/University of California, Los Angeles, Appropriateness Method was applied to combine current evidence with multidisciplinary expert opinion. A systematic literature review was conducted and used by the expert panel to rate appropriateness of radiation therapy options for different clinical scenarios. Treatments were categorized by median rating as Appropriate, May Be Appropriate, or Rarely Appropriate. In the neoadjuvant setting, chemoradiation was rated Appropriate and the ratings indicated short-course radiation therapy, chemotherapy alone, and no neoadjuvant therapy are potential options in selected patients. However, neoadjuvant endorectal brachytherapy was rated Rarely Appropriate. For adjuvant therapy, chemoradiation (plus ≥4 months of chemotherapy) was rated Appropriate and chemotherapy alone May Be Appropriate for most scenarios. For medically inoperable patients, definitive external beam radiation therapy and chemotherapy alone were rated May Be Appropriate, whereas endorectal brachytherapy and chemoradiation plus endorectal brachytherapy were possible approaches for some scenarios. The last option, definitive chemoradiation, was rated Appropriate to May Be Appropriate based on performance status. Finally, for patients with low-lying tumors refusing abdominoperineal resection, definitive chemoradiation alone, chemoradiation plus endorectal brachytherapy, and chemoradiation plus external beam radiation therapy were all rated Appropriate. This Clinical Practice Statement demonstrated the central role of radiation therapy in stage II-III rectal cancer management and evaluated ways to better individualize its use in the neoadjuvant, adjuvant, and definitive settings. Ongoing trials may clarify areas of continuing uncertainty and allow further customization. Copyright © 2015 American Society for Radiation Oncology. Published by Elsevier Inc. All rights reserved.

Risk of secondary malignancies after radiation therapy for breast cancer: Comprehensive results.

PubMed

Burt, Lindsay M; Ying, Jian; Poppe, Matthew M; Suneja, Gita; Gaffney, David K

2017-10-01

To assess risks of secondary malignancies in breast cancer patients who received radiation therapy compared to patients who did not. The SEER database was used to identify females with a primary diagnosis of breast cancer as their first malignancy, during 1973-2008. We excluded patients with metastatic disease, age <18 years, no definitive surgical intervention, ipsilateral breast cancer recurrence, or who developed a secondary malignancy within 1 year of diagnosis. Standardized incidence ratios and absolute excess risk were calculated using SEER*Stat, version 8.2.1 and SAS, version 9.4. There were 374,993 patients meeting the inclusion criteria, with 154,697 who received radiation therapy. With a median follow-up of 8.9 years, 13% of patients (49,867) developed a secondary malignancy. The rate of secondary malignancies was significantly greater than the endemic rate in breast cancer patients treated without radiation therapy, (O/E 1.2, 95% CI 1.19-1.22) and with radiation therapy (O/E 1.33, 95% CI 1.31-1.35). Approximately 3.4% of secondary malignancies were attributable to radiation therapy. The increased risk of secondary malignancies in breast cancer patients treated with radiation therapy compared to those without was significant regardless of age at breast cancer diagnosis (p < 0.01) and more pronounced with longer latency periods. There was an increased risk of secondary malignancies for breast cancer patients both with and without radiation therapy compared to the general population. There was an increased risk in specific sites for patients treated with radiation therapy. This risk was most evident in young patients and who had longer latency periods. Copyright © 2017 Elsevier Ltd. All rights reserved.

Vitamin D Deficiency Is Associated With the Severity of Radiation-Induced Proctitis in Cancer Patients

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ghorbanzadeh-Moghaddam, Amir; Gholamrezaei, Ali, E-mail: Gholamrezaei@med.mui.ac.ir; Poursina Hakim Research Institution, Isfahan

Purpose: Radiation-induced injury to normal tissues is a common complication of radiation therapy in cancer patients. Considering the role of vitamin D in mucosal barrier hemostasis and inflammatory responses, we investigated whether vitamin D deficiency is associated with the severity of radiation-induced acute proctitis in cancer patients. Methods and Materials: This prospective observational study was conducted in cancer patients referred for pelvic radiation therapy. Serum concentration of 25-hydroxyvitamin D was measured before radiation therapy. Vitamin D deficiency was defined as 25-hydroxyvitamin D concentrations of <35 nmol/L and <40 nmol/L in male and female patients, respectively, based on available normative data.more » Acute proctitis was assessed after 5 weeks of radiation therapy (total received radiation dose of 50 Gy) and graded from 0 to 4 using Radiation Therapy Oncology Group (RTOG) criteria. Results: Ninety-eight patients (57.1% male) with a mean age of 62.8 ± 9.1 years were studied. Vitamin D deficiency was found in 57 patients (58.1%). Symptoms of acute proctitis occurred in 72 patients (73.4%) after radiation therapy. RTOG grade was significantly higher in patients with vitamin D deficiency than in normal cases (median [interquartile range] of 2 [0.5-3] vs 1 [0-2], P=.037). Vitamin D deficiency was associated with RTOG grade of ≥2, independent of possible confounding factors; odds ratio (95% confidence interval) = 3.07 (1.27-7.50), P=.013. Conclusions: Vitamin D deficiency is associated with increased severity of radiation-induced acute proctitis. Investigating the underlying mechanisms of this association and evaluating the effectiveness of vitamin D therapy in preventing radiation-induced acute proctitis is warranted.« less

Randomized Noninferiority Trial of Reduced High-Dose Volume Versus Standard Volume Radiation Therapy for Muscle-Invasive Bladder Cancer: Results of the BC2001 Trial (CRUK/01/004)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Huddart, Robert A., E-mail: robert.huddart@icr.ac.uk; Hall, Emma; Hussain, Syed A.

2013-10-01

Purpose: To test whether reducing radiation dose to uninvolved bladder while maintaining dose to the tumor would reduce side effects without impairing local control in the treatment of muscle-invasive bladder cancer. Methods and Materials: In this phase III multicenter trial, 219 patients were randomized to standard whole-bladder radiation therapy (sRT) or reduced high-dose volume radiation therapy (RHDVRT) that aimed to deliver full radiation dose to the tumor and 80% of maximum dose to the uninvolved bladder. Participants were also randomly assigned to receive radiation therapy alone or radiation therapy plus chemotherapy in a partial 2 × 2 factorial design. Themore » primary endpoints for the radiation therapy volume comparison were late toxicity and time to locoregional recurrence (with a noninferiority margin of 10% at 2 years). Results: Overall incidence of late toxicity was less than predicted, with a cumulative 2-year Radiation Therapy Oncology Group grade 3/4 toxicity rate of 13% (95% confidence interval 8%, 20%) and no statistically significant differences between groups. The difference in 2-year locoregional recurrence free rate (RHDVRT − sRT) was 6.4% (95% confidence interval −7.3%, 16.8%) under an intention to treat analysis and 2.6% (−12.8%, 14.6%) in the “per-protocol” population. Conclusions: In this study RHDVRT did not result in a statistically significant reduction in late side effects compared with sRT, and noninferiority of locoregional control could not be concluded formally. However, overall low rates of clinically significant toxicity combined with low rates of invasive bladder cancer relapse confirm that (chemo)radiation therapy is a valid option for the treatment of muscle-invasive bladder cancer.« less

Tangential migratory pathways of subpallial origin in the embryonic telencephalon of sharks: evolutionary implications.

PubMed

Quintana-Urzainqui, Idoia; Rodríguez-Moldes, Isabel; Mazan, Sylvie; Candal, Eva

2015-09-01

Tangential neuronal migration occurs along different axes from the axis demarcated by radial glia and it is thought to have evolved as a mechanism to increase the diversity of cell types in brain areas, which in turn resulted in increased complexity of functional networks. In the telencephalon of amniotes, different embryonic tangential pathways have been characterized. However, little is known about the exact routes of migrations in basal vertebrates. Cartilaginous fishes occupy a key phylogenetic position to assess the ancestral condition of vertebrate brain organization. In order to identify putative subpallial-derived tangential migratory pathways in the telencephalon of sharks, we performed a detailed analysis of the distribution pattern of GAD and Dlx2, two reliable markers of tangentially migrating interneurons of subpallial origin in the developing forebrain. We propose the existence of five tangential routes directed toward different telencephalic regions. We conclude that four of the five routes might have emerged in the common ancestor of jawed vertebrates. We have paid special attention to the characterization of the proposed migratory pathway directed towards the olfactory bulbs. Our results suggest that it may be equivalent to the "rostral migratory stream" of mammals and led us to propose a hypothesis about its evolution. The analysis of the final destinations of two other streams allowed us to identify the putative dorsal and medial pallium of sharks, the regions from which the neocortex and hippocampus might have, respectively, evolved. Derived features were also reported and served to explain some distinctive traits in the morphology of the telencephalon of cartilaginous fishes.

Is effective force application in handrim wheelchair propulsion also efficient?

PubMed

Bregman, D J J; van Drongelen, S; Veeger, H E J

2009-01-01

Efficiency in manual wheelchair propulsion is low, as is the fraction of the propulsion force that is attributed to the moment of propulsion of the wheelchair. In this study we tested the hypothesis that a tangential propulsion force direction leads to an increase in physiological cost, due to (1) the sub-optimal use of elbow flexors and extensors, and/or (2) the necessity of preventing of glenohumeral subluxation. Five able-bodied and 11 individuals with a spinal cord injury propelled a wheelchair while kinematics and kinetics were collected. The results were used to perform inverse dynamical simulations with input of (1) the experimentally obtained propulsion force, and (2) only the tangential component of that force. In the tangential force condition the physiological cost was over 30% higher, while the tangential propulsion force was only 75% of the total experimental force. According to model estimations, the tangential force condition led to more co-contraction around the elbow, and a higher power production around the shoulder joint. The tangential propulsion force led to a significant, but small 4% increase in necessity for the model to compensate for glenohumeral subluxation, which indicates that this is not a likely cause of the decrease in efficiency. The present findings support the hypothesis that the observed force direction in wheelchair propulsion is a compromise between efficiency and the constraints imposed by the wheelchair-user system. This implies that training should not be aimed at optimization of the propulsion force, because this may be less efficient and more straining for the musculoskeletal system.

SU-E-T-583: Operated Left Breast and Chest Wall Radiotherapy: A Dosimetric Comparison Between 3DCRT, IMRT and VMAT

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sarkar, B; Roy, S; Munshi, A

2015-06-15

Purpose: To evaluate the comparative dosimetric efficacy between field and field 3DCRT(FnF), multiple field Intensity modulated radiotherapy (SnS IMRT) and, partial arc volumetric modulated arc therapy (VMAT) in case of post operative left side breast and chest wall irradiation. Methods: CT study set of fifteen post-operative left breast and chest wall patient was tested for a treatment plan of 50Gy in 25 fraction using partial arc VMAT, SnSIMRT and tangential beam 3DCRT . 3DCRT FnF gantry angle was ranging for left medial tangential 290±17{sup 0} and Lt lateral tangential l14°±12{sup 0}. For IMRT four fixed beam at gantry angle G130{supmore » 0} G110{sup 0} G300{sup 0} and G330{sup 0} was used, in case of insufficient dose another beam G150{sup 0} was added. In case of partial arc VMAT, lateral tangential arc G130{sup 0}-G100{sup 0} and medial tangential arc G280{sup 0}-G310{sup 0}. Inverse optimization was opted to cover at least 95%PTV by 95% prescription dose (RxD) and a strong weightage on reduction of heart and lung dose. PTV coverage was evaluated for it’s clinically acceptability depending on the tumor spatial location and its quadrant. Out of the three plans, any one was used for the actual patient treatment. Results: Dosimetric analysis done for breast PTV, left lung, heart and the opposite breast. PTV mean dose and maximum dose was 5129.8±214.8cGy, 4749.0±329.7cGy, 5024.6±73.4cGy and 5855.2±510.7cGy, 5340.7±146.1cGy, 5347.2±196.8cGy for FnF, VMAT and IMRT respectively. Ipsilateral lung volume receiving 20Gy and 5Gy was 23.6±9.5cGy and 32.7±10.3cGy for FnF, 18.6±8.7cGy and 38.8±15.2cGy for VMAT and 25.7±9.6cGy and 50.7±8.4cGy for IMRT respectively. Heart mean and 2cc dose was 867.9±456.7cGy and 5038.5±184.3cGy for FnF, 532.6±263cGy and 3632.1±990.6 for VMAT, 711±229.9cGy and 4421±463.7cGy for IMRT respectively. VMAT shows minimum contralateral breast dose 168±113.8cGy. Conclusion: VMAT shows a better tumor conformity, minimum heart, ipsilateral lung and opposite breast dose. Cardiac Toxicity and risk of contralateral breast cancer can be reduce using VMAT.« less

Tobacco Smoking During Radiation Therapy for Head-and-Neck Cancer Is Associated With Unfavorable Outcome

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, Allen M., E-mail: allen.chen@ucdmc.ucdavis.ed; Chen, Leon M.; Vaughan, Andrew

Purpose: To evaluate the effect of continued cigarette smoking among patients undergoing radiation therapy for head-and-neck cancer by comparing the clinical outcomes among active smokers and quitters. Methods and Materials: A review of medical records identified 101 patients with newly diagnosed squamous cell carcinoma of the head and neck who continued to smoke during radiation therapy. Each active smoker was matched to a control patient who had quit smoking before initiation of radiation therapy. Matching was based on tobacco history (pack-years), primary site, age, sex, Karnofsky Performance Status, disease stage, radiation dose, chemotherapy use, year of treatment, and whether surgicalmore » resection was performed. Outcomes were compared by use of Kaplan-Meier analysis. Normal tissue effects were graded according to the Radiation Therapy Oncology Group/European Organization for the Treatment of Cancer toxicity criteria. Results: With a median follow-up of 49 months, active smokers had significantly inferior 5-year overall survival (23% vs. 55%), locoregional control (58% vs. 69%), and disease-free survival (42% vs. 65%) compared with the former smokers who had quit before radiation therapy (p < 0.05 for all). These differences remained statistically significant when patients treated by postoperative or definitive radiation therapy were analyzed separately. The incidence of Grade 3 or greater late complications was also significantly increased among active smokers compared with former smokers (49% vs. 31%, p = 0.01). Conclusions: Tobacco smoking during radiation therapy for head-and-neck cancer is associated with unfavorable outcomes. Further studies analyzing the biologic and molecular reasons underlying these differences are planned.« less

The Peripheral Myeloid Expansion Driven by Murine Cancer Progression Is Reversed by Radiation Therapy of the Tumor

PubMed Central

Crittenden, Marka R.; Savage, Talicia; Cottam, Benjamin; Bahjat, Keith S.; Redmond, William L.; Bambina, Shelly; Kasiewicz, Melissa; Newell, Pippa; Jackson, Andrew M.; Gough, Michael J.

2013-01-01

Expansion of myeloid-lineage leukocytes in tumor-bearing mice has been proposed as a cause of systemic immunosuppression. We demonstrate that radiation therapy of tumors leads to a decline in myeloid cell numbers in the blood and a decrease in spleen size. The frequency of myeloid cells does not decline to the level seen in tumor-free mice: we demonstrate that metastatic disease can prevent myeloid cell numbers from returning to baseline, and that tumor recurrence from residual disease correlates with re-expansion of myeloid lineage cells. Radiation therapy results in increased proliferation of T cells in the spleen and while T cell responses to foreign antigens are not altered by tumor burden or myeloid cell expansion, responses to tumor-associated antigens are increased after radiation therapy. These data demonstrate that myeloid cell numbers are directly linked to primary tumor burden, that this population contracts following radiation therapy, and that radiation therapy may open a therapeutic window for immunotherapy of residual disease. PMID:23936036

Radiation Therapy for Cancer

Cancer.gov

Radiation therapy is a type of cancer treatment that uses high doses of radiation to kill cancer cells and shrink tumors. Learn about the types of radiation, why side effects happen, which ones you might have, and more.

[The Learning Effectiveness of Nurses Participating in a Simulated Radiation Therapy Skin Care Workshop].

PubMed

Lee, Yu-San; Kao, Yu-Hsiu

2016-08-01

The skin reaction rate is 60-95% in cancer patients that receive radiation therapy. This therapy is likely to cause physical and mental discomfort and prolong treatment for patients. The current emphasis on lectures rather than practice to help nurses learn proper skin care practices likely imposes difficulties for nurses to handle various clinical situations. To investigate the learning effectiveness of a simulated radiation therapy skin care workshop for nurses. A total of 34 nurses at a hospital in one health system in northern Taiwan who had never used radiation therapy to provide care to patients were enrolled in this quasi-experimental study. A single group pretest, posttest and post-posttest (6 weeks after intervention) approach was used. At the simulated radiation therapy skin care workshop, we used teaching strategies including Ausubel's direct instruction teaching method and practice on simulated wounds on pig skins. Outcomes were evaluated using "the questionnaire of radiation therapy skin care" and "direct observation of procedural skills checklist". The results from the simulated radiation therapy skin care workshop were analyzed using GEE (generalized estimating equation). The post-posttest and posttest scores increased significantly; knowledge mean score 3.14 (< .001) vs 2.64 (< .001), attitude mean score 2.06 (p < .05) vs 2.24 (p < .001), and skill mean score 2.79 (p < .001) vs 1.68 (p < .001). The simulated radiation therapy skin care workshop demonstrated significant and positive effects on learning outcomes. Therefore, we recommend incorporating this workshop into clinical nursing education and training strategies in the future.

Calcified basal ganglionic mass 12 years after radiation therapy for medulloblastoma

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lichtor, T.; Wollmann, R.L.; Brown, F.D.

1984-04-01

A patient treated 12 years previously with an operation and radiation therapy for a medulloblastoma developed weakness of the left hand and perivascular calcification involving the right internal capsule and caudate nucleus. These findings are considered possible long-term complications of the radiation therapy.

MR-guided radiation therapy: transformative technology and its role in the central nervous system

PubMed Central

Tseng, Chia-Lin; Balter, James M.; Teng, Feifei; Parmar, Hemant A.; Sahgal, Arjun

2017-01-01

Abstract This review article describes advancement of magnetic resonance imaging technologies in radiation therapy planning, guidance, and adaptation of brain tumors. The potential for MR-guided radiation therapy to improve outcomes and the challenges in its adoption are discussed. PMID:28380637

A novel imaging approach for prostate cancer is tested in new clinical trial | Center for Cancer Research

Cancer.gov

Prostate cancer patients who have failed standard radiation therapy have the options of surgery, radioactive seed implantation or cryoablation. Deborah Citrin, M.D., of the Radiation Oncology Branch is leading a study of stereotactic body radiation therapy (SBRT) to treat prostate cancer that has recurred locally after standard radiation therapy. The goal of this study is to

Cherenkov Video Imaging Allows for the First Visualization of Radiation Therapy in Real Time

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jarvis, Lesley A., E-mail: Lesley.a.jarvis@hitchcock.org; Norris Cotton Cancer Center at the Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire; Zhang, Rongxiao

Purpose: To determine whether Cherenkov light imaging can visualize radiation therapy in real time during breast radiation therapy. Methods and Materials: An intensified charge-coupled device (CCD) camera was synchronized to the 3.25-μs radiation pulses of the clinical linear accelerator with the intensifier set × 100. Cherenkov images were acquired continuously (2.8 frames/s) during fractionated whole breast irradiation with each frame an accumulation of 100 radiation pulses (approximately 5 monitor units). Results: The first patient images ever created are used to illustrate that Cherenkov emission can be visualized as a video during conditions typical for breast radiation therapy, even with complex treatment plans,more » mixed energies, and modulated treatment fields. Images were generated correlating to the superficial dose received by the patient and potentially the location of the resulting skin reactions. Major blood vessels are visible in the image, providing the potential to use these as biological landmarks for improved geometric accuracy. The potential for this system to detect radiation therapy misadministrations, which can result from hardware malfunction or patient positioning setup errors during individual fractions, is shown. Conclusions: Cherenkoscopy is a unique method for visualizing surface dose resulting in real-time quality control. We propose that this system could detect radiation therapy errors in everyday clinical practice at a time when these errors can be corrected to result in improved safety and quality of radiation therapy.« less

Bendable X-ray Optics at the ALS: Design, Tuning, Performance and Applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Advanced Light Source, Lawrence Berkeley National Laboratory; Yashchuk, Valeriy V.; Church, Matthew N.

2008-09-08

We review the development at the Advanced Light Source (ALS) of bendable x-ray optics widely used for focusing of beams of soft and hard x-rays. Typically, the focusing is divided in the tangential and sagittal directions into two elliptically cylindrical reflecting elements, the so-called Kirkpatrick-Baez (KB) pair [1]. Because fabrication of elliptical surfaces is complicated, the cost of directly fabricated tangential elliptical cylinders is often prohibitive. This is in contrast to flat optics, that are simpler to manufacture and easier to measure by conventional interferometry. The figure of a flat substrate can be changed by placing torques (couples) at eachmore » end. Equal couples form a tangential cylinder, and unequal couples can approximate a tangential ellipse or parabola. We review the nature of the bending, requirements and approaches to the mechanical design, and describe a technique developed at the ALS Optical Metrology Laboratory (OML) for optimal tuning of bendable mirrors before installation in the beamline [2]. The tuning technique adapts a method previously used to adjust bendable mirrors on synchrotron radiation beamlines [3]. However, in our case, optimal tuning of a bendable mirror is based on surface slope trace data obtained with a slope measuring instrument--in our case, the long trace profiler (LTP). We show that due to the near linearity of the bending problem, the minimal set of data, necessary for tuning of two benders, consists of only three slope traces measured before and after a single adjustment of each bending couple. We provide an algorithm that was used in dedicated software for finding optimal settings for the mirror benders. The algorithm is based on the method of regression analysis with experimentally found characteristic functions of the benders. The resulting approximation to the functional dependence of the desired slope shape provides nearly final settings for the benders. Moreover, the characteristic functions of the benders found in the course of tuning, can be used for retuning of the optics to a new desired shape without removing it from the beamline and re-measuring with the LTP. The result of practical use of the developed technique to precisely tune a KB mirror used at the ALS for micro-focusing is also presented. We also describe a simple ray trace using the profiler data which shows expected performance in the beamline and compare the simulation with experimental data. In summary, we also discuss the next steps in the systematic improvement of optical performance for the application of KB pairs in synchrotron beamlines at the ALS.« less

The Utility of Proton Beam Therapy with Concurrent Chemotherapy for the Treatment of Esophageal Cancers

PubMed Central

Lin, Steven H.

2011-01-01

The standard of care for the management of locally advanced esophageal cancers in the United States is chemotherapy combined with radiation, either definitively, or for those who could tolerate surgery, preoperatively before esophagectomy. Although the appropriate radiation dose remains somewhat controversial, the quality of the radiation delivery is critical for the treatment of esophageal cancer since the esophagus is positioned close to vital structures, such as the heart and lung. The volume and relative doses to these normal tissues affect acute and late term complications. Advances in radiation delivery from 2D to 3D conformal radiation therapy, to Intensity Modulated Radiation Therapy (IMRT) or charged particle therapy (carbon ion or proton beam therapy (PBT)), allow incremental improvements in the therapeutic ratio. This could have implications in non-cancer related morbidity for long term survivors. This article reviews the evolution in radiation technologies and the use of PBT with chemotherapy in the management of esophageal cancer. PMID:24213126

DNA Double-Strand Break Repair as Determinant of Cellular Radiosensitivity to Killing and Target in Radiation Therapy

PubMed Central

Mladenov, Emil; Magin, Simon; Soni, Aashish; Iliakis, George

2013-01-01

Radiation therapy plays an important role in the management of a wide range of cancers. Besides innovations in the physical application of radiation dose, radiation therapy is likely to benefit from novel approaches exploiting differences in radiation response between normal and tumor cells. While ionizing radiation induces a variety of DNA lesions, including base damages and single-strand breaks, the DNA double-strand break (DSB) is widely considered as the lesion responsible not only for the aimed cell killing of tumor cells, but also for the general genomic instability that leads to the development of secondary cancers among normal cells. Homologous recombination repair (HRR), non-homologous end-joining (NHEJ), and alternative NHEJ, operating as a backup, are the major pathways utilized by cells for the processing of DSBs. Therefore, their function represents a major mechanism of radiation resistance in tumor cells. HRR is also required to overcome replication stress – a potent contributor to genomic instability that fuels cancer development. HRR and alternative NHEJ show strong cell-cycle dependency and are likely to benefit from radiation therapy mediated redistribution of tumor cells throughout the cell-cycle. Moreover, the synthetic lethality phenotype documented between HRR deficiency and PARP inhibition has opened new avenues for targeted therapies. These observations make HRR a particularly intriguing target for treatments aiming to improve the efficacy of radiation therapy. Here, we briefly describe the major pathways of DSB repair and review their possible contribution to cancer cell radioresistance. Finally, we discuss promising alternatives for targeting DSB repair to improve radiation therapy and cancer treatment. PMID:23675572

[Radiation therapy and redox imaging].

PubMed

Matsumoto, Ken-ichiro

2015-01-01

Radiation therapy kills cancer cells in part by flood of free radicals. Radiation ionizes and/or excites water molecules to create highly reactive species, i.e. free radicals and/or reactive oxygen species. Free radical chain reactions oxidize biologically important molecules and thereby disrupt their function. Tissue oxygen and/or redox status, which can influence the course of the free radical chain reaction, can affect the efficacy of radiation therapy. Prior observation of tissue oxygen and/or redox status is helpful for planning a safe and efficient course of radiation therapy. Magnetic resonance-based redox imaging techniques, which can estimate tissue redox status non-invasively, have been developed not only for diagnostic information but also for estimating the efficacy of treatment. Redox imaging is now spotlighted to achieve radiation theranostics.

SU-F-J-178: A Computer Simulation Model Observer for Task-Based Image Quality Assessment in Radiation Therapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dolly, S; Mutic, S; Anastasio, M

Purpose: Traditionally, image quality in radiation therapy is assessed subjectively or by utilizing physically-based metrics. Some model observers exist for task-based medical image quality assessment, but almost exclusively for diagnostic imaging tasks. As opposed to disease diagnosis, the task for image observers in radiation therapy is to utilize the available images to design and deliver a radiation dose which maximizes patient disease control while minimizing normal tissue damage. The purpose of this study was to design and implement a new computer simulation model observer to enable task-based image quality assessment in radiation therapy. Methods: A modular computer simulation framework wasmore » developed to resemble the radiotherapy observer by simulating an end-to-end radiation therapy treatment. Given images and the ground-truth organ boundaries from a numerical phantom as inputs, the framework simulates an external beam radiation therapy treatment and quantifies patient treatment outcomes using the previously defined therapeutic operating characteristic (TOC) curve. As a preliminary demonstration, TOC curves were calculated for various CT acquisition and reconstruction parameters, with the goal of assessing and optimizing simulation CT image quality for radiation therapy. Sources of randomness and bias within the system were analyzed. Results: The relationship between CT imaging dose and patient treatment outcome was objectively quantified in terms of a singular value, the area under the TOC (AUTOC) curve. The AUTOC decreases more rapidly for low-dose imaging protocols. AUTOC variation introduced by the dose optimization algorithm was approximately 0.02%, at the 95% confidence interval. Conclusion: A model observer has been developed and implemented to assess image quality based on radiation therapy treatment efficacy. It enables objective determination of appropriate imaging parameter values (e.g. imaging dose). Framework flexibility allows for incorporation of additional modules to include any aspect of the treatment process, and therefore has great potential for both assessment and optimization within radiation therapy.« less

[Traumatic lesion of the optic nerve head by flying fish: a case report].

PubMed

Martin, M; Orgül, S; Robertson, A; Flammer, J

2004-05-01

Traumatic lesion to the optic nerve often leads to severe and persistent functional loss. A male patient was transferred to our hospital from the University Eye Clinic of Guadeloupe 5 days after ocular injury caused by a flying fish. Visual function was light perception. The anterior part of the eye and retina were unremarkable. A computer tomography disclosed a fracture of the sphenoid sinus, with a little bone fragment (DD: foreign body) located close to the optic nerve. Therapy had been started with Aminopenicillin combined with clavulan acid (Augmentin) i. v., 500 ml methylprednisolone (Solumedrol) i. v., lysine-acetyl salicylate (Aspegic) and topical application of dexamethasone combined with neomycin/polymyxin B (Maxitrol). We continued this therapy and intensified it by adding nimodipine (Nimotop) 30 1-1-1 and acetazolamide retard (Diamox sustet) 1-0-1. Unfortunately visual function did not recover under therapy. Traumatic lesions of the optic nerve head, especially when due to axial or tangential forces, can lead to severe and irreversible functional loss. Severe traumatic lesions, even bone fractures induced by flying fish are not a seldom encounter in the Caribbean Sea.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wong, Jonathan; Xu, Beibei; Moores Cancer Center, University of California San Diego, La Jolla, California

Purpose/Objective: Palliative radiation therapy represents an important treatment option among patients with advanced cancer, although research shows decreased use among older patients. This study evaluated age-related patterns of palliative radiation use among an elderly Medicare population. Methods and Materials: We identified 63,221 patients with metastatic lung, breast, prostate, or colorectal cancer diagnosed between 2000 and 2007 from the Surveillance, Epidemiology, and End Results (SEER)-Medicare linked database. Receipt of palliative radiation therapy was extracted from Medicare claims. Multivariate Poisson regression analysis determined residual age-related disparity in the receipt of palliative radiation therapy after controlling for confounding covariates including age-related differences inmore » patient and demographic covariates, length of life, and patient preferences for aggressive cancer therapy. Results: The use of radiation decreased steadily with increasing patient age. Forty-two percent of patients aged 66 to 69 received palliative radiation therapy. Rates of palliative radiation decreased to 38%, 32%, 24%, and 14% among patients aged 70 to 74, 75 to 79, 80 to 84, and over 85, respectively. Multivariate analysis found that confounding covariates attenuated these findings, although the decreased relative rate of palliative radiation therapy among the elderly remained clinically and statistically significant. On multivariate analysis, compared to patients 66 to 69 years old, those aged 70 to 74, 75 to 79, 80 to 84, and over 85 had a 7%, 15%, 25%, and 44% decreased rate of receiving palliative radiation, respectively (all P<.0001). Conclusions: Age disparity with palliative radiation therapy exists among older cancer patients. Further research should strive to identify barriers to palliative radiation among the elderly, and extra effort should be made to give older patients the opportunity to receive this quality of life-enhancing treatment at the end of life.« less

Brachial Plexus-Associated Neuropathy After High-Dose Radiation Therapy for Head-and-Neck Cancer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, Allen M., E-mail: allen.chen@ucdmc.ucdavis.edu; Hall, William H.; Li, Judy

2012-09-01

Purpose: To identify clinical and treatment-related predictors of brachial plexus-associated neuropathies after radiation therapy for head-and-neck cancer. Methods and Materials: Three hundred thirty patients who had previously completed radiation therapy for head-and-neck cancer were prospectively screened using a standardized instrument for symptoms of neuropathy thought to be related to brachial plexus injury. All patients were disease-free at the time of screening. The median time from completion of radiation therapy was 56 months (range, 6-135 months). One-hundred fifty-five patients (47%) were treated by definitive radiation therapy, and 175 (53%) were treated postoperatively. Radiation doses ranged from 50 to 74 Gy (median,more » 66 Gy). Intensity-modulated radiation therapy was used in 62% of cases, and 133 patients (40%) received concurrent chemotherapy. Results: Forty patients (12%) reported neuropathic symptoms, with the most common being ipsilateral pain (50%), numbness/tingling (40%), motor weakness, and/or muscle atrophy (25%). When patients with <5 years of follow-up were excluded, the rate of positive symptoms increased to 22%. On univariate analysis, the following factors were significantly associated with brachial plexus symptoms: prior neck dissection (p = 0.01), concurrent chemotherapy (p = 0.01), and radiation maximum dose (p < 0.001). Cox regression analysis confirmed that both neck dissection (p < 0.001) and radiation maximum dose (p < 0.001) were independently predictive of symptoms. Conclusion: The incidence of brachial plexus-associated neuropathies after radiation therapy for head-and-neck cancer may be underreported. In view of the dose-response relationship identified, limiting radiation dose to the brachial plexus should be considered when possible.« less

Severe myositis of the hip flexors after pre-operative chemoradiation therapy for locally advanced rectal cancer: case report.

PubMed

Florczynski, Matthew M; Sanatani, Michael S; Mai, Lauren; Fisher, Barbara; Moulin, Dwight E; Cao, Jeffrey; Louie, Alexander V; Pope, Janet E; Leung, Eric

2016-03-22

The use of neoadjuvant radiation therapy and chemotherapy in the treatment of locally advanced rectal adenocarcinoma has been shown to reduce disease recurrence when combined with surgery and adjuvant chemotherapy. We report a case of a patient who developed a debilitating bilateral myopathy of the hip flexors after successful treatment for rectal cancer. To the best of our knowledge, this is the first such complication from radiation therapy reported in a patient with colorectal cancer. The disproportionate severity of our patient's myopathy relative to the dose of radiation used also makes this case unique among reports of neuromuscular complications from radiation therapy. The patient is a 65-year-old male with node negative, high-grade adenocarcinoma of the rectum penetrating through the distal rectal wall. He underwent neoadjuvant concurrent pelvic radiation therapy and capecitabine-based chemotherapy, followed by abdominoperineal resection and post-operative FOLFOX chemotherapy. Five months post-completion of pelvic radiotherapy and 2 months after the completion of adjuvant chemotherapy, he presented with bilateral weakness of the iliopsoas muscles and severe pain radiating to the groin. The patient improved with 40 mg/d of prednisone, which was gradually tapered to 2 mg/d over 6 months, with substantial recovery of muscle strength and elimination of pain. The timing, presentation and response of our patient's symptoms to corticosteroids are most consistent with a radiation recall reaction. Radiation recall is a phenomenon whereby previously irradiated tissue becomes vulnerable to toxicity by subsequent systemic therapy and is rarely associated with myopathies. Radiation recall should be considered a potential complication of neoadjuvant radiation therapy for rectal cancer, and for ongoing research into the optimization of treatment for these patients. Severe myopathies caused by radiation recall may be fully reversible with corticosteroid treatment.

[Brain metastases: Focal treatment (surgery and radiation therapy) and cognitive consequences].

PubMed

Reygagne, Emmanuelle; Du Boisgueheneuc, Foucaud; Berger, Antoine

2017-04-01

Brain metastases represent the first cause of malignant brain tumor. Without radiation therapy, prognosis was poor with fast neurological deterioration, and a median overall survival of one month. Nowadays, therapeutic options depend on brain metastases presentation, extra brain disease, performance status and estimated prognostic (DS GPA). Therefore, for oligometastatic brain patients with a better prognosis, this therapeutic modality is controversial. In fact, whole-brain radiation therapy improves neurological outcomes, but it can also induce late neuro-cognitive sequelae for long-term survivors of brain metastases. Thus, in this strategy for preserving good cognitive functions, stereotactic radiation therapy is a promising treatment. Delivering precisely targeted radiation in few high-doses in one to four brain metastases, allows to reduce radiation damage to normal tissues and it should allow to decrease radiation-induced cognitive decline. In this paper, we will discuss about therapeutic strategies (radiation therapy and surgery) with their neuro-cognitive consequences for brain metastases patients and future concerning preservation of cognitive functions. Copyright © 2016 Société Française du Cancer. Published by Elsevier Masson SAS. All rights reserved.

Contact problem on indentation of an elastic half-plane with an inhomogeneous coating by a flat punch in the presence of tangential stresses on a surface

NASA Astrophysics Data System (ADS)

Volkov, Sergei S.; Vasiliev, Andrey S.; Aizikovich, Sergei M.; Sadyrin, Evgeniy V.

2018-05-01

Indentation of an elastic half-space with functionally graded coating by a rigid flat punch is studied. The half-plane is additionally subjected to distributed tangential stresses. Tangential stresses are represented in a form of Fourier series. The problem is reduced to the solution of two dual integral equations over even and odd functions describing distribution of unknown normal contact stresses. The solutions of these dual integral equations are constructed by the bilateral asymptotic method. Approximated analytical expressions for contact normal stresses are provided.

A role for intermediate radial glia in the tangential expansion of the mammalian cerebral cortex.

PubMed

Reillo, Isabel; de Juan Romero, Camino; García-Cabezas, Miguel Ángel; Borrell, Víctor

2011-07-01

The cerebral cortex of large mammals undergoes massive surface area expansion and folding during development. Specific mechanisms to orchestrate the growth of the cortex in surface area rather than in thickness are likely to exist, but they have not been identified. Analyzing multiple species, we have identified a specialized type of progenitor cell that is exclusive to mammals with a folded cerebral cortex, which we named intermediate radial glia cell (IRGC). IRGCs express Pax6 but not Tbr2, have a radial fiber contacting the pial surface but not the ventricular surface, and are found in both the inner subventricular zone and outer subventricular zone (OSVZ). We find that IRGCs are massively generated in the OSVZ, thus augmenting the numbers of radial fibers. Fanning out of this expanding radial fiber scaffold promotes the tangential dispersion of radially migrating neurons, allowing for the growth in surface area of the cortical sheet. Accordingly, the tangential expansion of particular cortical regions was preceded by high proliferation in the underlying OSVZ, whereas the experimental reduction of IRGCs impaired the tangential dispersion of neurons and resulted in a smaller cortical surface. Thus, the generation of IRGCs plays a key role in the tangential expansion of the mammalian cerebral cortex.

Kalker's algorithm Fastsim solves tangential contact problems with slip-dependent friction and friction anisotropy

NASA Astrophysics Data System (ADS)

Piotrowski, J.

2010-07-01

This paper presents two extensions of Kalker's algorithm Fastsim of the simplified theory of rolling contact. The first extension is for solving tangential contact problems with the coefficient of friction depending on slip velocity. Two friction laws have been considered: with and without recuperation of the static friction. According to the tribological hypothesis for metallic bodies shear failure, the friction law without recuperation of static friction is more suitable for wheel and rail than the other one. Sample results present local quantities inside the contact area (division to slip and adhesion, traction) as well as global ones (creep forces as functions of creepages and rolling velocity). For the coefficient of friction diminishing with slip, the creep forces decay after reaching the maximum and they depend on the rolling velocity. The second extension is for solving tangential contact problems with friction anisotropy characterised by a convex set of the permissible tangential tractions. The effect of the anisotropy has been shown on examples of rolling without spin and in the presence of pure spin for the elliptical set. The friction anisotropy influences tangential tractions and creep forces. Sample results present local and global quantities. Both extensions have been described with the same language of formulation and they may be merged into one, joint algorithm.

Cyclone reactor with internal separation and axial recirculation

DOEpatents

Becker, F.E.; Smolensky, L.A.

1988-07-19

A cyclone combustor apparatus contains a circular partition plate containing a central circular aperture is described. The partition plate divides the apparatus into a cylindrical precombustor chamber and a combustor chamber. A coal-water slurry is passed axially into the inlet end of the precombustor chamber, and primary air is passed tangentially into said chamber to establish a cyclonic air flow. Combustion products pass through the partition plate aperture and into the combustor chamber. Secondary air may also be passed tangentially into the combustor chamber adjacent the partition plate to maintain the cyclonic flow. Flue gas is passed axially out of the combustor chamber at the outlet end and ash is withdrawn tangentially from the combustor chamber at the outlet end. A first mixture of flue gas and ash may be tangentially withdrawn from the combustor chamber at the outlet end and recirculated to the axial inlet of the precombustor chamber with the coal-water slurry. A second mixture may be tangentially withdrawn from the outlet end and passed to a heat exchanger for cooling. Cooled second mixture is then recirculated to the axial inlet of the precombustor chamber. In another embodiment a single cyclone combustor chamber is provided with both the recirculation streams of the first mixture and the second mixture. 10 figs.

Cyclone reactor with internal separation and axial recirculation

DOEpatents

Becker, Frederick E.; Smolensky, Leo A.

1989-01-01

A cyclone combustor apparatus contains a circular partition plate containing a central circular aperture. The partition plate divides the apparatus into a cylindrical precombustor chamber and a combustor chamber. A coal-water slurry is passed axially into the inlet end of the precombustor chamber, and primary air is passed tangentially into said chamber to establish a cyclonic air flow. Combustion products pass through the partition plate aperture and into the combustor chamber. Secondary air may also be passed tangentially into the combustor chamber adjacent the partition plate to maintain the cyclonic flow. Flue gas is passed axially out of the combustor chamber at the outlet end and ash is withdrawn tangentially from the combuston chamber at the outlet end. A first mixture of flue gas and ash may be tangentially withdrawn from the combustor chamber at the outlet end and recirculated to the axial inlet of the precombustor chamber with the coal-water slurry. A second mixture of flue gas and ash may be tangentially withdrawn from the outlet end of the combustor chamber and passed to a heat exchanger for cooling. Cooled second mixture is then recirculated to the axial inlet of the precombustor chamber. In another embodiment a single cyclone combustor chamber is provided with both the recirculation streams of the first mixture and the second mixture.

A new isocentric technique for exact geometric matching in the radiotherapy of the breast and ipsilateral supraclavicular fossa using dual asymmetric jaws.

PubMed

Romeo, Nando

2012-10-01

In some clinical situations breast or chest wall radiotherapy for cancer is given in association with supraclavicular fossa irradiation. Often the treatment is delivered by two tangential fields to the breast or chest wall and an anterior field that irradiates the supraclavicular region. The tissue between the breast or chest wall and the supraclavicular region may be under or overdosed, because of the junction between the two tangential fields and the anterior field. To present a new isocentric technique for exact geometric matching between the two tangential fields and the anterior field. Patients are positioned with both arms raised. Using three-dimensional trigonometry, two half-fields, with isocenter between the breast and the supraclavicular region, are easily matched. The tangential fields have a collimator rotation to protect the lung without additional shielding. The correct gantry, collimator and couch positions are defined for the anterior field to match the tangential fields. A general formula for exact geometric matching in radiotherapy of the breast and supraclavicular fossa is presented. The method does not require additional shielding to eliminate divergence other than the four independent jaws. The result is simple to implement in modern delivery facilities. Copyright © 2011 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

Radiation Therapy Side Effects

Cancer.gov

Radiation therapy has side effects because it not only kills or slows the growth of cancer cells, it can also affect nearby healthy cells. Many people who get radiation therapy experience fatigue. Other side effects depend on the part of the body that is being treated. Learn more about possible side effects.

77 FR 68891 - Medicare Program; Revisions to Payment Policies Under the Physician Fee Schedule, DME Face-to...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-11-16

... Area ICD International Classification of Diseases IMRT Intensity Modulated Radiation Therapy IOM... Stereotactic body radiation therapy SGR Sustainable growth rate TC Technical component TIN Tax identification... Clinical Lab Fee Schedule, which is unaffected by the misvalued code initiative. Radiation therapy centers...

21 CFR 892.5710 - Radiation therapy beam-shaping block.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Radiation therapy beam-shaping block. 892.5710 Section 892.5710 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Therapeutic Devices § 892.5710 Radiation therapy beam-shaping...

Current external beam radiation therapy quality assurance guidance: does it meet the challenges of emerging image-guided technologies?

PubMed

Palta, Jatinder R; Liu, Chihray; Li, Jonathan G

2008-01-01

The traditional prescriptive quality assurance (QA) programs that attempt to ensure the safety and reliability of traditional external beam radiation therapy are limited in their applicability to such advanced radiation therapy techniques as three-dimensional conformal radiation therapy, intensity-modulated radiation therapy, inverse treatment planning, stereotactic radiosurgery/radiotherapy, and image-guided radiation therapy. The conventional QA paradigm, illustrated by the American Association of Physicists in Medicine Radiation Therapy Committee Task Group 40 (TG-40) report, consists of developing a consensus menu of tests and device performance specifications from a generic process model that is assumed to apply to all clinical applications of the device. The complexity, variation in practice patterns, and level of automation of high-technology radiotherapy renders this "one-size-fits-all" prescriptive QA paradigm ineffective or cost prohibitive if the high-probability error pathways of all possible clinical applications of the device are to be covered. The current approaches to developing comprehensive prescriptive QA protocols can be prohibitively time consuming and cost ineffective and may sometimes fail to adequately safeguard patients. It therefore is important to evaluate more formal error mitigation and process analysis methods of industrial engineering to more optimally focus available QA resources on process components that have a significant likelihood of compromising patient safety or treatment outcomes.

EGFR Targeted Therapies and Radiation: Optimizing Efficacy by Appropriate Drug Scheduling and Patient Selection

PubMed Central

Cuneo, Kyle C.; Nyati, Mukesh K.; Ray, Dipankar; Lawrence, Theodore S.

2015-01-01

The epidermal growth factor receptor (EGFR) plays an important role in tumor progression and treatment resistance for many types of malignancies including head and neck, colorectal, and nonsmall cell lung cancer. Several EGFR targeted therapies are efficacious as single agents or in combination with chemotherapy. Given the toxicity associated with chemoradiation and poor outcomes seen in several types of cancers, combinations of EGFR targeted agents with or without chemotherapy have been tested in patients receiving radiation. To date, the only FDA approved use of an anti-EGFR therapy in combination with radiation therapy is for locally advanced head and neck cancer. Given the important role EGFR plays in lung and colorectal cancer and the benefit of EGFR inhibition combined with chemotherapy in these disease sites, it is perplexing why EGFR targeted therapies in combination with radiation or chemoradiation have not been more successful. In this review we summarize the clinical findings of EGFR targeted therapies combined with radiation and chemoradiation regimens. We then discuss the interaction between EGFR and radiation including radiation induced EGFR signaling, the effect of EGFR on DNA damage repair, and potential mechanisms of radiosensitization. Finally, we examine the potential pitfalls with scheduling EGFR targeted therapies with chemoradiation and the use of predictive biomarkers to improve patient selection. PMID:26205191

Novel technologies and theoretical models in radiation therapy of cancer patients using 6.3 MeV fast neutrons produced by U-120 cyclotron

NASA Astrophysics Data System (ADS)

Musabaeva, L. I.; Startseva, Zh. A.; Gribova, O. V.; Velikaya, V. V.; Lisin, V. A.

2016-08-01

The analysis of clinical use of neutron therapy with 6 MeV fast neutrons compared to conventional radiation therapy was carried out. The experience of using neutron and mixed neutron and photon therapy in patients with different radio-resistant malignant tumors shows the necessity of further studies and development of the novel approaches to densely-ionizing radiation. The results of dosimetry and radiobiological studies have been the basis for planning clinical programs for neutron therapy. Clinical trials over the past 30 years have shown that neutron therapy successfully destroys radio-resistant cancers, including salivary gland tumors, adenoidcystic carcinoma, inoperable sarcomas, locally advanced head and neck tumors, and locally advanced prostate cancer. Radiation therapy with 6.3 MeV fast neutrons used alone and in combination with photon therapy resulted in improved long-term treatment outcomes in patients with radio-resistant malignant tumors.

Electric currents and fields induced in cells in the human brain by radiation from hand-held cellular telephones

NASA Astrophysics Data System (ADS)

King, Ronold W. P.

2000-01-01

After a review of recent work on the interaction of electromagnetic fields from cellular telephones with the human head, the structural and radiating properties of two common types of transceivers are determined. These include the impedance and current amplitude distribution of the antennas. The tangential electric field maintained by the antennas on the adjacent surface of the head is next determined. From this, the electric field propagating through the skull into the brain is analyzed and, from it, the electric field in spherical and long cylindrical cells is determined. It ranges from 27 to 13.5 V/m in the first 3 cm inside the skull. Of interest is the fact that the induced field in the interior of all cells, regardless of their shape, is the same as the incident field in the brain. It is hoped that biomedical scientists will review these results and determine possible biological effects.

The behavior of a liquid drop levitated and drastically flattened by an intense sound field

NASA Technical Reports Server (NTRS)

Lee, C. P.; Anilkumar, A. V.; Wang, Taylor G.

1992-01-01

The deformation and break-up are studied of a liquid drop in levitation through the radiation pressure. Using high-speed photography ripples are observed on the central membrane of the drop, atomization of the membrane by emission of satellite drops from its unstable ripples, and shattering of the drop after upward buckling like an umbrella, or after horizontal expansion like a sheet. These effects are captured on video. The ripples are theorized to be capillary waves generated by the Faraday instability excited by the sound vibration. Atomization occurs whenever the membrane becomes so thin that the vibration is sufficiently intense. The vibration leads to a destabilizing Bernoulli correction in the static pressure. Buckling occurs when an existent equilibrium is unstable to a radial (i.e., tangential) motion of the membrane because of the Bernoulli effect. Besides, the radiation stress at the rim of the drop is a suction stress which can make equilibrium impossible, leading to the horizontal expansion and the subsequent break-up.

Prostate brachytherapy

MedlinePlus

Implant therapy - prostate cancer; Radioactive seed placement; Internal radiation therapy - prostate; High dose radiation (HDR) ... CT scan to plan and then place the seeds that deliver radiation into your prostate. The seeds ...

The Impact of Radiation Oncologists on the Early Adoption of Hypofractionated Radiation Therapy for Early-Stage Breast Cancer.

PubMed

Boero, Isabel J; Gillespie, Erin F; Hou, Jiayi; Paravati, Anthony J; Kim, Ellen; Einck, John P; Yashar, Catheryn; Mell, Loren K; Murphy, James D

2017-03-01

Despite multiple randomized trials showing the efficacy of hypofractionated radiation therapy in early-stage breast cancer, the United States has been slow to adopt this treatment. The goal of this study was to evaluate the impact of individual radiation oncologists on the early adoption of hypofractionated radiation therapy for early-stage breast cancer. We identified 22,233 Medicare beneficiaries with localized breast cancer that was diagnosed from 2004 to 2011 who underwent breast-conserving surgery with adjuvant radiation. Multilevel, multivariable logistic models clustered by radiation oncologist and geographic practice area were used to determine the impact of the provider and geographic region on the likelihood of receiving hypofractionated compared with standard fractionated radiation therapy while controlling for a patient's clinical and demographic covariates. Odds ratios (OR) describe the impact of demographic or clinical covariates, and the median OR (MOR) describes the relative impact of the individual radiation oncologist and geographic region on the likelihood of undergoing hypofractionated radiation therapy. Among the entire cohort, 2333 women (10.4%) were treated with hypofractionated radiation therapy, with unadjusted rates ranging from 0.0% in the bottom quintile of radiation oncologists to 30.4% in the top quintile. Multivariable analysis found that the individual radiation oncologist (MOR 3.08) had a greater impact on the use of hypofractionation than did geographic region (MOR 2.10) or clinical and demographic variables. The impact of the provider increased from the year 2004 to 2005 (MOR 2.82) to the year 2010 to 2011 (MOR 3.16) despite the publication of long-term randomized trial results in early 2010. Male physician and radiation oncologists treating the highest volume of breast cancer patients were less likely to perform hypofractionation (P<.05). The individual radiation oncologist strongly influenced the likelihood of a patient's receiving hypofractionated radiation therapy, and this trend increased despite the publication of long-term data showing equivalence to standard fractionation. Future research should focus on physician-related factors that influence this decision. Copyright © 2016 Elsevier Inc. All rights reserved.

Adjuvant Radiation Therapy Treatment Time Impacts Overall Survival in Gastric Cancer

DOE Office of Scientific and Technical Information (OSTI.GOV)

McMillan, Matthew T.; Department of Surgery, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania; Ojerholm, Eric

Purpose: Prolonged radiation therapy treatment time (RTT) is associated with worse survival in several tumor types. This study investigated whether delays during adjuvant radiation therapy impact overall survival (OS) in gastric cancer. Methods and Materials: The National Cancer Data Base was queried for patients with resected gastric cancer who received adjuvant radiation therapy with National Comprehensive Cancer Network–recommended doses (45 or 50.4 Gy) between 1998 and 2006. RTT was classified as standard (45 Gy: 33-36 days, 50.4 Gy: 38-41 days) or prolonged (45 Gy: >36 days, 50.4 Gy: >41 days). Cox proportional hazards models evaluated the association between the following factors and OS: RTT, interval from surgery to radiationmore » therapy initiation, interval from surgery to radiation therapy completion, radiation therapy dose, demographic/pathologic and operative factors, and other elements of adjuvant multimodality therapy. Results: Of 1591 patients, RTT was delayed in 732 (46%). Factors associated with prolonged RTT were non-private health insurance (OR 1.3, P=.005) and treatment at non-academic facilities (OR 1.2, P=.045). Median OS and 5-year actuarial survival were significantly worse in patients with prolonged RTT compared with standard RTT (36 vs 51 months, P=.001; 39 vs 47%, P=.005); OS worsened with each cumulative week of delay (P<.0004). On multivariable analysis, prolonged RTT was associated with inferior OS (hazard ratio 1.2, P=.002); the intervals from surgery to radiation therapy initiation or completion were not. Prolonged RTT was particularly detrimental in patients with node positivity, inadequate nodal staging (<15 nodes examined), and those undergoing a cycle of chemotherapy before chemoradiation therapy. Conclusions: Delays during adjuvant radiation therapy appear to negatively impact survival in gastric cancer. Efforts to minimize cumulative interruptions to <7 days should be considered.« less

Central Nervous System Disease, Education, and Race Impact Radiation Refusal in Pediatric Cancer Patients.

PubMed

Patel, Chirayu G; Stavas, Mark; Perkins, Stephanie; Shinohara, Eric T

2017-07-01

To investigate the determinants of radiation therapy refusal in pediatric cancer, we used the Surveillance, Epidemiology, and End Results registry to identify 24,421 patients who met the eligibility criteria, diagnosed between 1974 and 2012. Patients had any stage of cancer, were aged 0 to 19, and received radiation therapy or refused radiation therapy when it was recommended. One hundred twenty-eight patients (0.52%) refused radiation therapy when it was recommended. Thirty-two percent of patients who refused radiation therapy ultimately died from their cancer, at a median of 7 months after diagnosis (95% confidence interval, 3-11 mo), as compared with 29.0% of patients who did not refuse radiation therapy died from their cancer, at a median of 17 months after diagnosis (95% confidence interval, 17-18 mo). On multivariable analysis, central nervous system (CNS) site, education, and race were associated with radiation refusal. The odds ratio for radiation refusal for patients with CNS disease was 1.62 (P=0.009) as compared with patients without CNS disease. For patients living in a county with ≥10% residents having less than ninth grade education, the odds ratio for radiation refusal was 1.71 (P=0.008) as compared with patients living in a county with <10% residents having less than ninth grade education. Asian, Pacific Islander, Alaska Native, and American Indian races had an odds ratio of 2.12 (P=0.002) for radiation refusal as compared with black or white race. Although the radiation refusal rate in the pediatric cancer population is low, we show that CNS site, education level, and race are associated with a significant difference in radiation refusal.

Contemporary Statewide Practice Pattern Assessment of the Palliative Treatment of Bone Metastasis.

PubMed

Spratt, Daniel E; Mancini, Brandon R; Hayman, James A; Boike, Thomas; Pierce, Lori J; Moran, Jean M; Dominello, Michael M; Fireman, Mark; Griffith, Kent; Jolly, Shruti

2018-06-01

Palliative radiation therapy for bone metastases is often viewed as a single entity, despite national guidelines providing input principally only for painful uncomplicated bone metastases. Data surrounding the treatment of bone metastases are often gleaned from questionnaires of what providers would theoretically do in practice or from population-based data lacking critical granular information. We investigated the real-world treatment of bone metastases with radiation therapy. Twenty diverse institutions across the state of Michigan had data extracted for their 10 most recent cases of radiation therapy delivered for the treatment of bone metastases at their institution between January and February 2017. Uni- and multivariable binary logistic regression was used to assess the use of single fraction (8 Gy × 1) radiation therapy. A total of 196 cases were eligible for inclusion. Twenty-eight different fractionation schedules were identified. The most common schedule was 3 Gy × 10 fractions (n = 100; 51.0%), 4 Gy × 5 fractions (n = 32; 16.3%), and 8 Gy × 1 (n = 15; 7.7%). The significant predictors for the use of single fraction radiation therapy were the presence of oligometastatic disease (P = .008), previous overlapping radiation therapy (P = .050), and academic practice type (P = .039). Twenty-nine cases (14.8%) received >10 fractions (median 15, range 11-20). Intensity modulated radiation therapy was used in 14 cases (7.1%), stereotactic body radiation therapy in 11 (5.6%), and image guidance with cone beam computed tomography in 11 (5.6%). Of the cases of simple painful bone metastases (no previous surgery, spinal cord compression, fracture, soft tissue extension, or overlapping previous radiation therapy; n = 70), only 12.9% were treated with 8 Gy × 1. Bone metastases represent a heterogeneous disease, and radiation therapy for bone metastases is similarly diverse. Future work is needed to understand the barriers to single fraction use, and clinical trials are necessary to establish appropriate guidelines for the breadth of this complex disease. Copyright © 2018 Elsevier Inc. All rights reserved.

Acupuncture in Treating Dry Mouth Caused By Radiation Therapy in Patients With Head and Neck Cancer | Division of Cancer Prevention

Cancer.gov

RATIONALE: Acupuncture may help relieve dry mouth caused by radiation therapy. PURPOSE: This randomized phase III trial is studying to see how well one set of acupuncture points work in comparison to a different set of acupuncture points or standard therapy in treating dry mouth caused by radiation therapy in patients with head and neck cancer. |

Impact of patient-specific factors, irradiated left ventricular volume, and treatment set-up errors on the development of myocardial perfusion defects after radiation therapy for left-sided breast cancer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Evans, Elizabeth S.; Prosnitz, Robert G.; Yu Xiaoli

2006-11-15

Purpose: The aim of this study was to assess the impact of patient-specific factors, left ventricle (LV) volume, and treatment set-up errors on the rate of perfusion defects 6 to 60 months post-radiation therapy (RT) in patients receiving tangential RT for left-sided breast cancer. Methods and Materials: Between 1998 and 2005, a total of 153 patients were enrolled onto an institutional review board-approved prospective study and had pre- and serial post-RT (6-60 months) cardiac perfusion scans to assess for perfusion defects. Of the patients, 108 had normal pre-RT perfusion scans and available follow-up data. The impact of patient-specific factors onmore » the rate of perfusion defects was assessed at various time points using univariate and multivariate analysis. The impact of set-up errors on the rate of perfusion defects was also analyzed using a one-tailed Fisher's Exact test. Results: Consistent with our prior results, the volume of LV in the RT field was the most significant predictor of perfusion defects on both univariate (p = 0.0005 to 0.0058) and multivariate analysis (p = 0.0026 to 0.0029). Body mass index (BMI) was the only significant patient-specific factor on both univariate (p = 0.0005 to 0.022) and multivariate analysis (p = 0.0091 to 0.05). In patients with very small volumes of LV in the planned RT fields, the rate of perfusion defects was significantly higher when the fields set-up 'too deep' (83% vs. 30%, p = 0.059). The frequency of deep set-up errors was significantly higher among patients with BMI {>=}25 kg/m{sup 2} compared with patients of normal weight (47% vs. 28%, p = 0.068). Conclusions: BMI {>=}25 kg/m{sup 2} may be a significant risk factor for cardiac toxicity after RT for left-sided breast cancer, possibly because of more frequent deep set-up errors resulting in the inclusion of additional heart in the RT fields. Further study is necessary to better understand the impact of patient-specific factors and set-up errors on the development of RT-induced perfusion defects.« less

Dependence of Coronary 3-Dimensional Dose Maps on Coronary Topologies and Beam Set in Breast Radiation Therapy: A Study Based on CT Angiographies

DOE Office of Scientific and Technical Information (OSTI.GOV)

Moignier, Alexandra, E-mail: alexandra.moignier@gmail.com; Broggio, David; Derreumaux, Sylvie

2014-05-01

Purpose: In left-side breast radiation therapy (RT), doses to the left main (LM) and left anterior descending (LAD) coronary arteries are usually assessed after delineation by prior anatomic knowledge on the treatment planning computed tomography (CT) scan. In this study, dose sensitivity due to interindividual coronary topology variation was assessed, and hot spots were located. Methods and Materials: Twenty-two detailed heart models, created from heart computed tomography angiographies, were fitted into a single representative female thorax. Two breast RT protocols were then simulated into a treatment planning system: the first protocol comprised tangential and tumoral bed beams (TGs{sub T}B) atmore » 50 + 16 Gy, the second protocol added internal mammary chain beams at 50 Gy to TGs{sub T}B (TGs{sub T}B{sub I}MC). For the heart, the LAD, and the LM, several dose indicators were calculated: dose-volume histograms, mean dose (D{sub mean}), minimal dose received by the most irradiated 2% of the volume (D{sub 2%}), and 3-dimensional (3D) dose maps. Variations of these indicators with anatomies were studied. Results: For the LM, the intermodel dispersion of D{sub mean} and D{sub 2%} was 10% and 11%, respectively, with TGs{sub T}B and 40% and 80%, respectively, with TGs{sub T}B{sub I}MC. For the LAD, these dispersions were 19% (D{sub mean}) and 49% (D{sub 2%}) with TGs{sub T}B and 35% (D{sub mean}) and 76% (D{sub 2%}) with TGs{sub T}B{sub I}MC. The 3D dose maps revealed that the internal mammary chain beams induced hot spots between 20 and 30 Gy on the LM and the proximal LAD for some coronary topologies. Without IMC beams, hot spots between 5 and 26 Gy are located on the middle and distal LAD. Conclusions: Coronary dose distributions with hot spot location and dose level can change significantly depending on coronary topology, as highlighted by 3D coronary dose maps. In clinical practice, coronary imaging may be required for a relevant coronary dose assessment, especially in cases of internal mammary chain irradiation.« less

Radiation therapy in the management of head-and-neck cancer of unknown primary origin: how does the addition of concurrent chemotherapy affect the therapeutic ratio?

PubMed

Chen, Allen M; Farwell, D Gregory; Lau, Derick H; Li, Bao-Qing; Luu, Quang; Donald, Paul J

2011-10-01

To determine how the addition of cisplatin-based concurrent chemotherapy to radiation therapy influences outcomes among a cohort of patients treated for head-and-neck cancer of unknown primary origin. The medical records of 60 consecutive patients treated by radiation therapy for squamous cell carcinoma of the head and neck presenting as cervical lymph node metastasis of occult primary origin were reviewed. Thirty-two patients (53%) were treated by concurrent chemoradiation, and 28 patients (47%) were treated by radiation therapy alone. Forty-five patients (75%) received radiation therapy after surgical resection, and 15 patients (25%) received primary radiation therapy. Thirty-five patients (58%) were treated by intensity-modulated radiotherapy. The 2-year estimates of overall survival, local-regional control, and progression-free survival were 89%, 89%, and 79%, respectively, among patients treated by chemoradiation, compared to 90%, 92%, and 83%, respectively, among patients treated by radiation therapy alone (p > 0.05, for all). Exploratory analysis failed to identify any subset of patients who benefited from the addition of concurrent chemotherapy to radiation therapy. The use of concurrent chemotherapy was associated with a significantly increased incidence of Grade 3+ acute and late toxicity (p < 0.001, for both). Concurrent chemoradiation is associated with significant toxicity without a clear advantage to overall survival, local-regional control, and progression-free survival in the treatment of head-and-neck cancer of unknown primary origin. Although selection bias cannot be ignored, prospective data are needed to further address this question. Copyright © 2011 Elsevier Inc. All rights reserved.

Predicted Rate of Secondary Malignancies Following Adjuvant Proton Versus Photon Radiation Therapy for Thymoma.

PubMed

Vogel, J; Lin, L; Litzky, L A; Berman, A T; Simone, C B

2017-10-01

Thymic malignancies are the most common tumors of the anterior mediastinum. The benefit of adjuvant radiation therapy for stage II disease remains controversial, and patients treated with adjuvant radiation therapy are at risk of late complications, including radiation-induced secondary malignant neoplasms (SMNs), that may reduce the overall benefit of treatment. We assess the risk of predicted SMNs following adjuvant proton radiation therapy compared with photon radiation therapy after resection of stage II thymic malignancies to determine whether proton therapy improves the risk-benefit ratio. Ten consecutive patients treated with double-scattered proton beam radiation therapy (DS-PBT) were prospectively enrolled in an institutional review board-approved proton registry study. All patients were treated with DS-PBT. Intensity modulated radiation therapy (IMRT) plans for comparison were generated. SMN risk was calculated based on organ equivalent dose. Patients had a median age of 65 years (range, 25-77 years), and 60% were men. All patients had stage II disease, and many had close or positive margins (60%). The median dose was 50.4 Gy (range, 50.4-54.0 Gy) in 1.8-Gy relative biological effectiveness daily fractions. No differences in target coverage were seen with DS-PBT compared with IMRT plans. Significant reductions were seen in mean and volumetric lung, heart, and esophageal doses with DS-PBT compared with IMRT plans (all P≤.01). Significant reductions in SMNs in the lung, breast, esophagus, skin, and stomach were seen with DS-PBT compared with IMRT. For patients with thymoma diagnosed at the median national age, 5 excess secondary malignancies per 100 patients would be avoided by treating them with protons instead of photons. Treatment with proton therapy can achieve comparable target coverage but significantly reduced doses to critical normal structures, which can lead to fewer predicted SMNs compared with IMRT. By decreasing expected late complications, proton therapy may improve the therapeutic ratio of adjuvant radiation therapy for patients with stage II thymic malignancies. Copyright © 2017 Elsevier Inc. All rights reserved.

Risk Factors Associated With Symptomatic Radiation Pneumonitis After Stereotactic Body Radiation Therapy for Stage I Non-Small Cell Lung Cancer.

PubMed

Shi, Shiming; Zeng, Zhaochong; Ye, Luxi; Huang, Yan; He, Jian

2017-06-01

Radiation pneumonitis is the most frequent acute pulmonary toxicity following stereotactic body radiation therapy for lung cancer. Here, we investigate clinical and dosimetric factors associated with symptomatic radiation pneumonitis in patients with stage I non-small cell lung cancer treated with stereotactic body radiation therapy. A total of 67 patients with stage I non-small cell lung cancer who received stereotactic body radiation therapy at our institution were enrolled, and their clinicopathological parameters and dosimetric parameters were recorded and analyzed. The median follow-up period was 26.4 months (range: 7-48 months). In univariate analysis, tumor size ( P = .041), mean lung dose ( P = .028), V2.5 ( P = .024), V5 ( P = .014), V10 ( P = .004), V20 ( P = .024), V30 ( P = .020), V40 ( P = .040), and V50 ( P = 0.040) were associated with symptomatic radiation pneumonitis. In multivariable logistic regression analysis, V10 ( P = .049) was significantly associated with symptomatic radiation pneumonitis. In conclusion, this study found that tumor size, mean lung dose, and V2.5 to V50 were risk factors markedly associated with symptomatic radiation pneumonitis. Our data suggested that lung V10 was the most significant factor, and optimizing lung V10 may reduce the risk of symptomatic radiation pneumonitis. For both central and peripheral stage I lung cancer, rate of radiation pneumonitis ≥grade 2 was low after stereotactic body radiation therapy with appropriate fraction dose.

21 CFR 892.5900 - X-ray radiation therapy system.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false X-ray radiation therapy system. 892.5900 Section 892.5900 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES...-rays used for radiation therapy. This generic type of device may include signal analysis and display...

21 CFR 892.5900 - X-ray radiation therapy system.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false X-ray radiation therapy system. 892.5900 Section 892.5900 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES...-rays used for radiation therapy. This generic type of device may include signal analysis and display...

21 CFR 892.5900 - X-ray radiation therapy system.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false X-ray radiation therapy system. 892.5900 Section 892.5900 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES...-rays used for radiation therapy. This generic type of device may include signal analysis and display...

21 CFR 892.5900 - X-ray radiation therapy system.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false X-ray radiation therapy system. 892.5900 Section 892.5900 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES...-rays used for radiation therapy. This generic type of device may include signal analysis and display...

21 CFR 892.5900 - X-ray radiation therapy system.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false X-ray radiation therapy system. 892.5900 Section 892.5900 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES...-rays used for radiation therapy. This generic type of device may include signal analysis and display...

Expression of NF-κB p50 in Tumor Stroma Limits the Control of Tumors by Radiation Therapy

PubMed Central

Crittenden, Marka R.; Cottam, Benjamin; Savage, Talicia; Nguyen, Cynthia; Newell, Pippa; Gough, Michael J.

2012-01-01

Radiation therapy aims to kill cancer cells with a minimum of normal tissue toxicity. Dying cancer cells have been proposed to be a source of tumor antigens and may release endogenous immune adjuvants into the tumor environment. For these reasons, radiation therapy may be an effective modality to initiate new anti-tumor adaptive immune responses that can target residual disease and distant metastases. However, tumors engender an environment dominated by M2 differentiated tumor macrophages that support tumor invasion, metastases and escape from immune control. In this study, we demonstrate that following radiation therapy of tumors in mice, there is an influx of tumor macrophages that ultimately polarize towards immune suppression. We demonstrate using in vitro models that this polarization is mediated by transcriptional regulation by NFκB p50, and that in mice lacking NFκB p50, radiation therapy is more effective. We propose that despite the opportunity for increased antigen-specific adaptive immune responses, the intrinsic processes of repair following radiation therapy may limit the ability to control residual disease. PMID:22761754

TH-F-202-01: MRI Basics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Miller, W.

MRI has excellent soft tissue contrast and can provide both anatomical and physiological information. It is becoming increasingly important in radiation therapy for treatment planning, image-guided radiation therapy, and treatment assessment. It is critically important at this time point to educate and update our medical physicists about MRI to prepare for the upcoming surge of MRI applications in radiation therapy. This session will review important basics of MR physics, pulse sequence designs, and current radiotherapy application, as well as showcase exciting new developments in MRI that can be potentially useful in radiation therapy. Learning Objectives: To learn basics of MRmore » physics and understand the differences between various pulse sequences To review current applications of MRI in radiation therapy.To discuss recent MRI advances for future MRI guided radiation therapy Partly supported by NIH (1R21CA165384).; W. Miller, Research supported in part by Siemens Healthcare; G. Li, My clinical research is in part supported by NIH U54CA137788. I have a collaborative research project with Philips Healthcare.; J. Cai, jing cai.« less

TH-F-202-02: Current Applications of MRI in Radiotherapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, G.

MRI has excellent soft tissue contrast and can provide both anatomical and physiological information. It is becoming increasingly important in radiation therapy for treatment planning, image-guided radiation therapy, and treatment assessment. It is critically important at this time point to educate and update our medical physicists about MRI to prepare for the upcoming surge of MRI applications in radiation therapy. This session will review important basics of MR physics, pulse sequence designs, and current radiotherapy application, as well as showcase exciting new developments in MRI that can be potentially useful in radiation therapy. Learning Objectives: To learn basics of MRmore » physics and understand the differences between various pulse sequences To review current applications of MRI in radiation therapy.To discuss recent MRI advances for future MRI guided radiation therapy Partly supported by NIH (1R21CA165384).; W. Miller, Research supported in part by Siemens Healthcare; G. Li, My clinical research is in part supported by NIH U54CA137788. I have a collaborative research project with Philips Healthcare.; J. Cai, jing cai.« less

Menhaden oil administration to dogs treated with radiation for nasal tumors demonstrates lower levels of tissue eicosanoids.

PubMed

Hansen, Rodney A; Anderson, Christine; Fettman, Martin J; Larue, Susan M; Davenport, Deborah J; Gross, Kathleen L; Richardson, Kristine L; Ogilvie, Gregory K

2011-12-01

Docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) or menhaden oil may reduce inflammatory eicosanoids (prostaglandin E₂, thromboxane B₂, leukotriene B₄, and 11-dehydro thromboxane B₂), matrix metalloproteinases (MMPs), and blood lactate in dogs with nasal carcinomas receiving radiation therapy. We hypothesized that menhaden oil would reduce inflammation from radiation damage and lower blood lactate levels in dogs with nasal carcinoma. In a randomized, double-blind, placebo-controlled clinical study, 12 dogs with malignant carcinomas of the nasal cavity were given dietary menhaden oil (DHA and EPA) or soybean oil (control) and then received radiation therapy. Megavoltage radiation was delivered in 18 fractions to a total dose of 56 Gy. Blood levels of DHA, EPA, insulin, glucose, lactic acid, and MMPs 2 and 9; resting energy expenditure; and inflammatory eicosanoids from nasal biopsies were measured throughout radiation therapy. Samples were obtained from each patient 1 week before the start of radiation therapy, at start of radiation, and 7, 18 (end of radiation therapy), and 42 days after radiation was initiated. Dogs that are fed with menhaden oil had significantly (P < .05) higher plasma concentration of DHA by 500% and EPA by 200% and had significantly lower tissue inflammatory eicosanoids and decreased resting energy expenditure by 20% when compared with controls. Increased plasma DHA was significantly associated (P < .05) with decreased plasma lactic acid and MMPs. These data may suggest that dietary fish oil could reduce some detrimental inflammatory eicosanoids and metabolic consequences of radiation therapy. Copyright © 2011 Elsevier Inc. All rights reserved.

Trimodality therapy in bladder cancer: Who, what and when?

PubMed Central

Premo, Christopher; Apolo, Andrea B.; Agarwal, Piyush K.

2015-01-01

Summary Radical cystectomy is a standard treatment for non-metastatic, muscle-invasive bladder cancer. Treatment with trimodality therapy consisting of maximal transurethral resection of the bladder tumor (TURBT) followed by concurrent chemotherapy and radiation has emerged as a method to preserve the native bladder in highly motivated patients. A number of factors can impact the likelihood of long term bladder preservation after trimodality therapy, and therefore should be taken into account when selecting patients. New radiation techniques such as intensity modulated radiation therapy and image guided radiation therapy may decrease the toxicity of radiotherapy in this setting, but remain an area of active study. Novel chemotherapy regimens may improve response rates and minimize toxicity. PMID:25882559

Stem cells rejuvenate radiation-impaired vasculogenesis in murine distraction osteogenesis.

PubMed

Deshpande, Sagar S; Gallagher, Kathleen K; Donneys, Alexis; Nelson, Noah S; Guys, Nicholas P; Felice, Peter A; Page, Erin E; Sun, Hongli; Krebsbach, Paul H; Buchman, Steven R

2015-03-01

Radiotherapy is known to be detrimental to bone and soft-tissue repair. Bone marrow stromal cells have been shown to enhance bone regeneration during distraction osteogenesis following radiation therapy. The authors posit that transplanted bone marrow stromal cells will significantly augment the mandibular vascularity devastated by radiation therapy. Nineteen male Lewis rats were split randomly into three groups: distraction osteogenesis only (n = 5), radiation therapy plus distraction osteogenesis (n = 7), and radiation therapy plus distraction osteogenesis with intraoperative placement of 2 million bone marrow stromal cells (n = 7). A mandibular osteotomy was performed, and an external fixator device was installed. From postoperative days 4 through 12, rats underwent a gradual 5.1-mm distraction followed by a 28-day consolidation period. On postoperative day 40, Microfil was perfused into the vasculature and imaging commenced. Vascular radiomorphometric values were calculated for regions of interest. An analysis of variance with post hoc Tukey or Games-Howell tests was used, dependent on data homogeneity. Stereologic analysis indicated significant remediation in vasculature in the bone marrow stromal cell group compared with the radiation therapy/distraction osteogenesis group. Each of five metrics idicated significant improvements from radiation therapy/distraction osteogenesis to the bone marrow stromal cell group, with no difference between the bone marrow stromal cell group and the distraction osteogenesis group. Bone marrow stromal cells used together with distraction osteogenesis can rejuvenate radiation-impaired vasculogenesis in the mandible, reversing radiation therapy-induced isotropy and creating a robust vascular network. Bone marrow stromal cells may offer clinicians an alternative reconstructive modality that could improve the lifestyle of patients with hypovascular bone.

Stages of Retinoblastoma

MedlinePlus

... internal radiation therapy may include the following: Plaque radiotherapy : Radioactive seeds are attached to one side of ... other nearby tissue from the radiation. Enlarge Plaque radiotherapy of the eye. A type of radiation therapy ...

Video Material as an Effective Educational Tool to Address Informational and Educational Needs of Cancer Patients Undergoing Radiation Therapy.

PubMed

Nathoo, Dilshad

2017-06-01

With increasing rates of cancer patients undergoing radiation therapy, the treatment itself can cause patients significant amounts of anxiety and distress. This can be attributed to the diagnosis of the disease, lack of knowledge of what radiation therapy is, expectations and management of side effects, and the lack of knowledge of supportive care for patients and their families. Providing patients with effective educational tools to meet the informational needs of cancer patients undergoing radiation therapy can empower patients and allow them to participate in treatment decision-making and their own healthcare. This discussion paper will evaluate several studies on the psychological impact of cancer patients undergoing radiation therapy and how video material can effectively meet the informational and educational needs of this patient population group.

Quality Assurance: Patient Chart Reviews

NASA Astrophysics Data System (ADS)

Oginni, B. M.; Odero, D. O.

2009-07-01

Recent developments in radiation therapy have immensely impacted the way the radiation dose is delivered to patients undergoing radiation treatments. However, the fundamental quality assurance (QA) issues underlying the radiation therapy still remain the accuracy of the radiation dose and the radiation safety. One of the major duties of clinical medical physicists in the radiation therapy departments still revolves around ensuring the accuracy of dose delivery to the planning target volume (PTV), the reduction of unintended radiation to normal organs and minimization of the radiation exposure to the medical personnel based on ALARA (as low as reasonably achievable) principle. Many of the errors in radiation therapy can be minimized through a comprehensive program of periodic checks. One of the QA procedures on the patient comes in the form of chart reviews which could be in either electronic or paper-based format. We present the quality assurance procedures that have to be performed on the patient records from the beginning and periodically to the end of the treatment, based on the guidelines from the American Association of Physicists in Medicine (AAPM) and American College of Physicians (ACP).

Modern radiation therapy for primary cutaneous lymphomas: field and dose guidelines from the International Lymphoma Radiation Oncology Group.

PubMed

Specht, Lena; Dabaja, Bouthaina; Illidge, Tim; Wilson, Lynn D; Hoppe, Richard T

2015-05-01

Primary cutaneous lymphomas are a heterogeneous group of diseases. They often remain localized, and they generally have a more indolent course and a better prognosis than lymphomas in other locations. They are highly radiosensitive, and radiation therapy is an important part of the treatment, either as the sole treatment or as part of a multimodality approach. Radiation therapy of primary cutaneous lymphomas requires the use of special techniques that form the focus of these guidelines. The International Lymphoma Radiation Oncology Group has developed these guidelines after multinational meetings and analysis of available evidence. The guidelines represent an agreed consensus view of the International Lymphoma Radiation Oncology Group steering committee on the use of radiation therapy in primary cutaneous lymphomas in the modern era. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

Benzydamine hydrochloride in prevention and management of pain in oral mucositis associated with radiation therapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Epstein, J.B.; Stevenson-Moore, P.

1986-08-01

Benzydamine hydrochloride rinse reduced pain associated with radiation mucositis when it was used during the course of radiation therapy. Fewer patients using benzydamine rinse required systemic analgesics. All patients using benzydamine tolerated the rinse well and continued with regular rinsing throughout the course of radiation therapy. Benzydamine hydrochloride is currently undergoing clinical trials in the United States for application for approval from the Food and Drug Administration.

Dynamics of fingertip contact during the onset of tangential slip

PubMed Central

Delhaye, Benoit; Lefèvre, Philippe; Thonnard, Jean-Louis

2014-01-01

Through highly precise perceptual and sensorimotor activities, the human tactile system continuously acquires information about the environment. Mechanical interactions between the skin at the point of contact and a touched surface serve as the source of this tactile information. Using a dedicated custom robotic platform, we imaged skin deformation at the contact area between the finger and a flat surface during the onset of tangential sliding movements in four different directions (proximal, distal, radial and ulnar) and with varying normal force and tangential speeds. This simple tactile event evidenced complex mechanics. We observed a reduction of the contact area while increasing the tangential force and proposed to explain this phenomenon by nonlinear stiffening of the skin. The deformation's shape and amplitude were highly dependent on stimulation direction. We conclude that the complex, but highly patterned and reproducible, deformations measured in this study are a potential source of information for the central nervous system and that further mechanical measurement are needed to better understand tactile perceptual and motor performances. PMID:25253033

Meninges control tangential migration of hem-derived Cajal-Retzius cells via CXCL12/CXCR4 signaling.

PubMed

Borrell, Víctor; Marín, Oscar

2006-10-01

Cajal-Retzius cells are critical in the development of the cerebral cortex, but little is known about the mechanisms controlling their development. Three focal sources of Cajal-Retzius cells have been identified in mice-the cortical hem, the ventral pallium and the septum-from where they migrate tangentially to populate the cortical surface. Using a variety of tissue culture assays and in vivo manipulations, we demonstrate that the tangential migration of cortical hem-derived Cajal-Retzius cells is controlled by the meninges. We show that the meningeal membranes are a necessary and sufficient substrate for the tangential migration of Cajal-Retzius cells. We also show that the chemokine CXCL12 secreted by the meninges enhances the dispersion of Cajal-Retzius cells along the cortical surface, while retaining them within the marginal zone in a CXCR4-dependent manner. Thus, the meningeal membranes are fundamental in the development of Cajal-Retzius cells and, hence, in the normal development of the cerebral cortex.

Numerical analysis of tangential slot blowing on a generic chined forebody

NASA Technical Reports Server (NTRS)

Agosta, Roxana M.

1994-01-01

A numerical study is performed to investigate the effects of tangential slot blowing on a generic chined forebody. The Reynolds-averaged, thin-layer, Navier-Stokes equations are solved to obtain the high-angle-of-attack viscous flow field about a generic chined forebody. Tangential slot blowing is investigated as a means of forebody flow control to generate side force and yawing moment on the forebody. The effects of jet mass flow ratios, angle of attack, and blowing slot location in the axial and circumferential directions are studied. The computed results are compared with available wind tunnel experimental data. The solutions with and without blowing are also analyzed using helicity density contours, surface flow patterns, and off-surface instantaneous streamlines. The results of this analysis provide details of the flow field about the generic chined forebody, as well as show that tangential slot blowing can be used as a means of forebody flow control to generate side force and yawing moment.

MO-DE-303-03: Session on quantitative imaging for assessment of tumor response to radiation therapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bowen, S.

This session will focus on quantitative imaging for assessment of tumor response to radiation therapy. This is a technically challenging method to translate to practice in radiation therapy. In the new era of precision medicine, however, delivering the right treatment, to the right patient, and at the right time, can positively impact treatment choices and patient outcomes. Quantitative imaging provides the spatial sensitivity required by radiation therapy for precision medicine that is not available by other means. In this Joint ESTRO -AAPM Symposium, three leading-edge investigators will present specific motivations for quantitative imaging biomarkers in radiation therapy of esophageal, headmore » and neck, locally advanced non-small cell lung cancer, and hepatocellular carcinoma. Experiences with the use of dynamic contrast enhanced (DCE) MRI, diffusion- weighted (DW) MRI, PET/CT, and SPECT/CT will be presented. Issues covered will include: response prediction, dose-painting, timing between therapy and imaging, within-therapy biomarkers, confounding effects, normal tissue sparing, dose-response modeling, and association with clinical biomarkers and outcomes. Current information will be presented from investigational studies and clinical practice. Learning Objectives: Learn motivations for the use of quantitative imaging biomarkers for assessment of response to radiation therapy Review the potential areas of application in cancer therapy Examine the challenges for translation, including imaging confounds and paucity of evidence to date Compare exemplary examples of the current state of the art in DCE-MRI, DW-MRI, PET/CT and SPECT/CT imaging for assessment of response to radiation therapy Van der Heide: Research grants from the Dutch Cancer Society and the European Union (FP7) Bowen: RSNA Scholar grant.« less

Imaging and characterization of primary and secondary radiation in ion beam therapy

NASA Astrophysics Data System (ADS)

Granja, Carlos; Martisikova, Maria; Jakubek, Jan; Opalka, Lukas; Gwosch, Klaus

2016-07-01

Imaging in ion beam therapy is an essential and increasingly significant tool for treatment planning and radiation and dose deposition verification. Efforts aim at providing precise radiation field characterization and online monitoring of radiation dose distribution. A review is given of the research and methodology of quantum-imaging, composition, spectral and directional characterization of the mixed-radiation fields in proton and light ion beam therapy developed by the IEAP CTU Prague and HIT Heidelberg group. Results include non-invasive imaging of dose deposition and primary beam online monitoring.

Missed Radiation Therapy and Cancer Recurrence

Cancer.gov

Patients who miss radiation therapy sessions during cancer treatment have an increased risk of their disease returning, even if they eventually complete their course of radiation treatment, according to a new study.

Treatment Option Overview (Retinoblastoma)

MedlinePlus

... internal radiation therapy may include the following: Plaque radiotherapy : Radioactive seeds are attached to one side of ... other nearby tissue from the radiation. Enlarge Plaque radiotherapy of the eye. A type of radiation therapy ...

Treatment Options for Retinoblastoma

MedlinePlus

... internal radiation therapy may include the following: Plaque radiotherapy : Radioactive seeds are attached to one side of ... other nearby tissue from the radiation. Enlarge Plaque radiotherapy of the eye. A type of radiation therapy ...

Bullying among radiation therapists: effects on job performance and work environment.

PubMed

Trad, Megan; Johnson, Jordan

2014-01-01

To identify the effects of workplace bullying in the radiation therapy department on job performance and explore the environment and morale of individuals who work with a bully. A quantitative research study was designed to assess the prevalence and effects of bullying in the radiation therapy workplace. A total of 308 radiation therapists participated in the study for a return rate of 46%. Of those, 194 indicated that workplace bullying was present either in their current workplace or in a previous radiation therapy environment and that it negatively affected job performance and satisfaction. Findings of this study indicate a need for evaluation of the radiation therapy workplace, education on how to identify and prevent bullying behavior, and better communication among members of the radiation therapy environment. Participants indicated that working in a hostile environment led to forgetfulness, ineffective communication, and perceived discrepancies in promotion and treatment by management. Any bullying behavior contributes to an overall toxic work environment, which is unhealthy and unsafe for patients and therapists. Those who manage therapists should promote a culture of safety and embrace their staff's independence.

Improving Quality and Access to Radiation Therapy-An IAEA Perspective.

PubMed

Abdel-Wahab, May; Zubizarreta, Eduardo; Polo, Alfredo; Meghzifene, Ahmed

2017-04-01

The International Atomic Energy Agency (IAEA) has been involved in radiation therapy since soon after its creation in 1957. In response to the demands of Member States, the IAEA׳s activities relating to radiation therapy have focused on supporting low- and middle-income countries to set up radiation therapy facilities, expand the scope of treatments, or gradually transition to new technologies. In addition, the IAEA has been very active in providing internationally harmonized guidelines on clinical, dosimetry, medical physics, and safety aspects of radiation therapy. IAEA clinical research has provided evidence for treatment improvement as well as highly effective resource-sparing interventions. In the process, training of researchers occurs through this program. To provide this support, the IAEA works with its Member States and multiple partners worldwide through several mechanisms. In this article, we review the main activities conducted by the IAEA in support to radiation therapy. IAEA support has been crucial for achieving tangible results in many low- and middle-income countries. However, long-term sustainability of projects can present a challenge, especially when considering health budget constraints and the brain drain of skilled professionals. The need for support remains, with more than 90% of patients in low-income countries lacking access to radiotherapy. Thus, the IAEA is expected to continue its support and strengthen quality radiation therapy treatment of patients with cancer. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Using Oxygen “Microbubbles” To Improve Radiation Therapy

Cancer.gov

Oxygen-carrying “microbubbles” could potentially improve the effectiveness of radiation therapy in the treatment of breast cancer, findings from a study in mice suggest. Using the bubbles along with radiation slowed tumor growth more than radiation alone, as this NCI Cancer Currents post reports.

Effects of Surgery and Proton Therapy on Cerebral White Matter of Craniopharyngioma Patients

DOE Office of Scientific and Technical Information (OSTI.GOV)

Uh, Jinsoo, E-mail: jinsoo.uh@stjude.org; Merchant, Thomas E.; Li, Yimei

Purpose: The purpose of this study was to determine radiation dose effect on the structural integrity of cerebral white matter in craniopharyngioma patients receiving surgery and proton therapy. Methods and Materials: Fifty-one patients (2.1-19.3 years of age) with craniopharyngioma underwent surgery and proton therapy in a prospective therapeutic trial. Anatomical magnetic resonance images acquired after surgery but before proton therapy were inspected to identify white matter structures intersected by surgical corridors and catheter tracks. Longitudinal diffusion tensor imaging (DTI) was performed to measure microstructural integrity changes in cerebral white matter. Fractional anisotropy (FA) derived from DTI was statistically analyzed for 51more » atlas-based white matter structures of the brain to determine radiation dose effect. FA in surgery-affected regions in the corpus callosum was compared to that in its intact counterpart to determine whether surgical defects affect radiation dose effect. Results: Surgical defects were seen most frequently in the corpus callosum because of transcallosal resection of tumors and insertion of ventricular or cyst catheters. Longitudinal DTI data indicated reductions in FA 3 months after therapy, which was followed by a recovery in most white matter structures. A greater FA reduction was correlated with a higher radiation dose in 20 white matter structures, indicating a radiation dose effect. The average FA in the surgery-affected regions before proton therapy was smaller (P=.0001) than that in their non–surgery-affected counterparts with more intensified subsequent reduction of FA (P=.0083) after therapy, suggesting that surgery accentuated the radiation dose effect. Conclusions: DTI data suggest that mild radiation dose effects occur in patients with craniopharyngioma receiving surgery and proton therapy. Surgical defects present at the time of proton therapy appear to accentuate the radiation dose effect longitudinally. This study supports consideration of pre-existing surgical defects and their locations in proton therapy planning and studies of treatment effect.« less

Radiation Therapy for Lung Cancer

MedlinePlus

... You have many issues to cope with. . . Your oncology team along with family and friends are available ... Therapy Answers www.rtanswers.org ABOUT THE RADIATION ONCOLOGY TEAM Radiation oncologists are cancer doctors who also ...

Late esophageal toxicity after radiation therapy for head and neck cancer.

PubMed

Chen, Allen M; Li, Bao-Qing; Jennelle, Richard L S; Lau, Derick H; Yang, Claus C; Courquin, Jean; Vijayakumar, Srinivasan; Purdy, James A

2010-02-01

The aim of this study was to determine the incidence of esophageal toxicity after radiation therapy for head and neck cancer. The records of 211 patients treated by radiation therapy for head and neck cancer were reviewed to identify those with dysphagia lasting more than 90 days after therapy. Late toxicity criteria established by the Radiation Therapy Oncology Group were used to score the symptoms. The incidence of grade 3+ esophageal toxicity at 3 and 6 months was 30% and 19%, respectively. The rate of gastrotomy-tube dependence at 3 and 6 months was 20% and 11%, respectively. Hypopharyngeal and unknown primary site (p = .01, for both), T4 disease (p = .01), and the use of concurrent chemotherapy (p = .001) were associated with grade 3+ esophageal toxicity and stricture formation. A significant proportion of patients exhibit symptoms of esophageal toxicity after radiation therapy for head and neck cancer. Therefore, preventive strategies need further investigation. Copyright 2009 Wiley Periodicals, Inc.

DEMONSTRATION OF SORBENT INJECTION TECHNOLOGY ON A TANGENTIALLY COAL-FIRED UTILITY BOILER (YORKTOWN LIMB DEMONSTRATION)

EPA Science Inventory

The report summarizes activities conducted and results achieved in an EPA-sponsored program to demonstrate Limestone Injection Multistage Burner (LIMB) technology on a tangentially fired coal-burning utility boiler, Virginia Power's 180-MWe Yorktown Unit No. 2. his successfully d...

SU-E-T-307: Dosimetric Comparison of Prone Versus Supine Positioning for Adjuvant Breast Radiation Therapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pope, C; O’Connor, B; Hayes, L

Purpose: The prone treatment position has been used to reduce ipsilateral lung and heart dose in left breast radiation. We conducted a retrospective study to evaluate the difference in the dosimetry between prone and supine treatment positions. Methods: Eight left breast cancer patients were simulated in both the supine and prone positions as a pretreatment evaluation for the optimal treatment position. Treatment plans were created for all patients in both the supine and prone positions using a field in field three dimensional planning technique. Prescribed dose was 45 Gy delivered by two tangential photon fields. Irradiated volume (IV) was evaluatedmore » by V50, V100, and dose to lung and heart by V5, V10, V20, and the mean dose were evaluated. Results: All dosimetry metrics for both the supine and prone plans met our internal normal structure guidelines which are based on Quantec data. The average IVs (50% and 100%) were 2223cc and 1361cc prone, 2315cc and 1315cc supine. The average ipsilateral lung Mean dose (0.83Gy prone vs 5.8Gy supine), V5 (1.6% prone vs 20.9% supine), V10 (0.78% prone vs 15% supine) and V20 (0.36% prone vs 11% supine) were significantly lower in prone position. Heart Mean dose (1.4Gy prone vs 2.9Gy supine), V10 (1.4% prone vs 5.0% supine) and V20 (0.4% prone vs 3.5% supine) were found improved for all patients except one where the mean dose was the same and all other values were improved. Conclusion: The prone position offer preferable dosimetry for all patients planned in our study. These patients were chosen based on the physician’s belief that they would benefit from prone treatment either because they had large pendulous breasts or due to the amount of heart seen in the field on CT simulation.« less

Method for protecting bone marrow against chemotherapeutic drugs and radiation therapy using transforming growth factor beta 1

DOE Office of Scientific and Technical Information (OSTI.GOV)

Keller, J.R.; Ruscetti, F.W.; Wiltrout, R.

1989-06-29

Presented is a method for protecting hematopoietic stem cells from the myelotoxicity of chemotherapeutic drugs or radiation therapy, which comprises administering to a subject a therapeutically effective amount of transforming growth factor beta 1 for protecting bone marrow from the myelotoxicity of chemotherapeutic drugs or radiation therapy.

Sentinel Lymph Node Biopsy: Quantification of Lymphedema Risk Reduction

DTIC Science & Technology

2006-10-01

dimensional internal mammary lymphoscintigraphy: implications for radiation therapy treatment planning for breast carcinoma. Int J Radiat Oncol Biol Phys...techniques based on conventional photon beams, intensity modulated photon beams and proton beams for therapy of intact breast. Radiother Oncol. Feb...Harris JR. Three-dimensional internal mammary lymphoscintigraphy: implications for radiation therapy treatment planning for breast carcinoma. Int J

Radiation techniques for esophageal cancer.

PubMed

Zhang, Minsi; Wu, Abraham J

2017-10-01

Radiotherapy plays a crucial role in the curative management of localized esophageal cancer, both as definitive and preoperative therapy. For definitive therapy, the standard radiation dose is 50.4 Gy in 28 fractions and should be delivered with concurrent chemotherapy. Chemoradiotherapy also has a wellestablished benefit in the preoperative setting, as established in the CROSS randomized trial. Radiation fields are typically generous, to account for subclinical extension of disease along the esophagus and to regional nodes. Three-dimensional conformal radiation is the current standard technique for esophageal cancer, though intensity-modulated radiation therapy is increasingly utilized and may improve the outcomes of esophageal radiotherapy by reducing radiation dose to critical normal tissues.

Communication skills training for radiation therapists: preparing patients for radiation therapy.

PubMed

Halkett, Georgia; O'Connor, Moira; Aranda, Sanchia; Jefford, Michael; Merchant, Susan; York, Debra; Miller, Lisa; Schofield, Penelope

2016-12-01

Patients sometimes present for radiation therapy with high levels of anxiety. Communication skills training may assist radiation therapists to conduct more effective consultations with patients prior to treatment planning and treatment commencement. The overall aim of our research is to examine the effectiveness of a preparatory programme 'RT Prepare' delivered by radiation therapists to reduce patient psychological distress. The purpose of this manuscript was to describe the communication skills workshops developed for radiation therapists and evaluate participants' feedback. Radiation therapists were invited to participate in two communication skills workshops run on the same day: (1) Consultation skills in radiation therapy and (2) Eliciting and responding to patients' emotional cues. Evaluation forms were completed. Radiation therapists' consultations with patients were then audio-recorded and evaluated prior to providing a follow-up workshop with participants. Nine full day workshops were held. Sixty radiation therapists participated. Positive feedback was received for both workshops with 88% or more participants agreeing or strongly agreeing with all the statements about the different components of the two workshops. Radiation therapists highlighted participating in role play with an actor, discussing issues; receiving feedback; acquiring new skills and knowledge; watching others role play and practicing with checklist were their favourite aspects of the initial workshop. The follow-up workshops provided radiation therapists with feedback on how they identified and addressed patients' psychological concerns; time spent with patients during consultations and the importance of finding private space for consultations. Communication skills training consisting of preparing patients for radiation therapy and eliciting and responding to emotional cues with follow-up workshops has the potential to improve radiation therapists' interactions with patients undergoing radiation therapy. Further research is warranted, similar to the RT Prepare study, to determine whether patient anxiety can be reduced as a result of improving communication and information provision. © 2016 The Authors. Journal of Medical Radiation Sciences published by John Wiley & Sons Australia, Ltd on behalf of Australian Society of Medical Imaging and Radiation Therapy and New Zealand Institute of Medical Radiation Technology.

Radiation therapy in the neonate

DOE Office of Scientific and Technical Information (OSTI.GOV)

Littman, P.; D'Angio, G.J.

Radiation therapy (RT) is frequently used in the management of children with cancer, but neonatal neoplasms are rare. Newborns represent 1.5% of the children with malignant diseases in the Tumor Registry at the Children's Hospital of Philadelphia over the last 30 years. Thus, occasionally the pediatrics radiation therapist must consider treating the very young infant. The specific radiation effects on growth and development must be weighed in reaching a therapeutic decision. All children are vulnerable to the late effects of radiation therapy, but the neonates may be more susceptible because of the immaturity of important organs such as the brain,more » lung, liver, kidney, and bone. In general, radiation therapy, should be avoided during the first several weeks of life because of the potential increased sensitivity of the liver and kidneys during that period. If radiation therapy is used at all during infancy, the benefits must be weighed against the possibility of significant late effects. Increasing knowledge of pediatric neoplasms has shown that some tumors (such as mesoblastic nephroma) require no treatment except for surgical excision; and other tumors, such as Stage IV-S neuroblastoma, may require very little treatment. In those tumors that require radiation therapy, the use of chemotherapy may allow reduction of the radiation dose. Furthermore, alterations of time-dose-fractionation schemes and careful attention to tumor volume with the use of special techniques, such as ''shrinking fields,'' may decrease the late adverse effects of treatment.« less

The promise of dynamic contrast-enhanced imaging in radiation therapy.

PubMed

Cao, Yue

2011-04-01

Dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) and computed tomography (CT) scanning are emerging as valuable tools to quantitatively map the spatial distribution of vascular parameters, such as perfusion, vascular permeability, blood volume, and mean transit time in tumors and normal organs. DCE MRI/CT have shown prognostic and predictive value for response of certain cancers to chemotherapy and radiation therapy. DCE MRI/CT offer the promise of early assessment of tumor response to radiation therapy, opening a window for adaptively optimizing radiation therapy based upon functional alterations that occur earlier than morphologic changes. DCE MRI/CT has also shown the potential of mapping dose responses in normal organs and tissue for evaluation of individual sensitivity to radiation, providing additional opportunities to minimize risks of radiation injury. The evidence for potentially applying DCE MRI and CT for selection and delineation of radiation boost targets is growing. The clinical use of DCE MRI and CT scanning as a biomarker or even a surrogate endpoint for radiation therapy assessment of tumor and normal organs must consider technical validation issues, including standardization, reproducibility, accuracy and robustness, and clinical validation of the sensitivity and specificity for each specific problem of interest. Although holding great promise, to date, DCE MRI and CT scanning have not been qualified as a surrogate endpoint for radiation therapy assessment or for treatment modification in any prospective phase III clinical trial for any tumor site. Copyright © 2011 Elsevier Inc. All rights reserved.

A Roadmap and Cost Implications of Establishing Comprehensive Cancer Care Using a Teleradiotherapy Network in a Group of Sub-Saharan African Countries With No Access to Radiation Therapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Datta, Niloy R., E-mail: niloyranjan.datta@ksa.ch; Heuser, Michael; Bodis, Stephan

Purpose: To propose a roadmap and explore the cost implications of establishing a teleradiotherapy network to provide comprehensive cancer care and capacity building in countries without access to radiation therapy. Methods and Materials: Ten low-income sub-Saharan countries with no current radiation therapy facilities were evaluated. A basic/secondary radiation therapy center (SRTC) with 2 teletherapy, 1 brachytherapy, 1 simulator, and a treatment planning facility was envisaged at a cost of 5 million US dollars (USD 5M). This could be networked with 1 to 4 primary radiation therapy centers (PRTC) with 1 teletherapy unit, each costing USD 2M. The numbers of PRTCsmore » and SRTCs for each country were computed on the basis of cancer incidence, assuming that a PRTC and SRTC could respectively treat 450 and 900 patients annually. Results: An estimated 71,215 patients in these countries will need radiation therapy in 2020. Stepwise establishment of a network with 99 PRTCs and 28 SRTCs would result in 155 teletherapy units and 96% access to radiation therapy. A total of 310 radiation oncologists, 155 medical physicists, and 465 radiation therapy technologists would be needed. Capacity building could be undertaken through telementoring by networking to various international institutions and professional societies. Total infrastructure costs would be approximately USD 860.88M, only 0.94% of the average annual gross domestic product of these 10 countries. A total of 1.04 million patients could receive radiation therapy during the 15-year lifespan of a teletherapy unit for an investment of USD 826.69 per patient. For the entire population of 218.32 million, this equates to USD 4.11 per inhabitant. Conclusion: A teleradiotherapy network could be a cost-contained innovative health care strategy to provide effective comprehensive cancer care through resource sharing and capacity building. The network could also be expanded to include other allied specialties. The proposal calls for active coordination between all national and international organizations backed up by strong geopolitical commitment and action from all stakeholders.« less

Radiation Therapy in the Management of Head-and-Neck Cancer of Unknown Primary Origin: How Does the Addition of Concurrent Chemotherapy Affect the Therapeutic Ratio?

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, Allen M., E-mail: allen.chen@ucdmc.ucdavis.edu; Farwell, D. Gregory; Lau, Derick H.

2011-10-01

Purpose: To determine how the addition of cisplatin-based concurrent chemotherapy to radiation therapy influences outcomes among a cohort of patients treated for head-and-neck cancer of unknown primary origin. Methods and Materials: The medical records of 60 consecutive patients treated by radiation therapy for squamous cell carcinoma of the head and neck presenting as cervical lymph node metastasis of occult primary origin were reviewed. Thirty-two patients (53%) were treated by concurrent chemoradiation, and 28 patients (47%) were treated by radiation therapy alone. Forty-five patients (75%) received radiation therapy after surgical resection, and 15 patients (25%) received primary radiation therapy. Thirty-five patientsmore » (58%) were treated by intensity-modulated radiotherapy. Results: The 2-year estimates of overall survival, local-regional control, and progression-free survival were 89%, 89%, and 79%, respectively, among patients treated by chemoradiation, compared to 90%, 92%, and 83%, respectively, among patients treated by radiation therapy alone (p > 0.05, for all). Exploratory analysis failed to identify any subset of patients who benefited from the addition of concurrent chemotherapy to radiation therapy. The use of concurrent chemotherapy was associated with a significantly increased incidence of Grade 3+ acute and late toxicity (p < 0.001, for both). Conclusions: Concurrent chemoradiation is associated with significant toxicity without a clear advantage to overall survival, local-regional control, and progression-free survival in the treatment of head-and-neck cancer of unknown primary origin. Although selection bias cannot be ignored, prospective data are needed to further address this question.« less

Current and long-term technologies of laser therapy

NASA Astrophysics Data System (ADS)

Ulashcyk, Vladimir S.; Volotovskaya, Anna V.

2007-06-01

Laser therapy, using low-energy laser radiation, is being more and more applied. The most applied technology is transcutaneous radiation of tissues by laser radiation. Originally, a direct action on a pathological site was mostly used, but recently more attention is given to reflexogenic areas, acupuncture points, and endocrine organ projection sites. The development of light-conductive engineering made it possible to practically apply intraorgan laser therapy. This technology is widely spread in gynecology, otorhinolaryngology, urology, gastroenterology, etc. Close to it are different versions of intratissue laser therapy (intraosteal, periosteal, myofascial). A special kind of laser therapy is laser hemotherapy. Depending on the techniques and protocol of its application, there are extracorporeal, intravascular, and supravenous ways of action. According to our comparative investigations, supravenous hemotherapy by its therapeutic efficacy and major medicinal effects can be well compared with intravascular laser hemotherapy. With good prospects and efficiency is laser therapy as a combination of laser and other physical factors. Magnetolaser therapy has been scientifically substantiated and practically applied so far. Theoretically and experimentally substantiated is a combined application of laser radiation and physical factors such as ultrasound, direct current field, vacuum, cryotherapy, etc. Experimental research and few so far clinical observations are indicative of prospects of a complex application of laser radiation and drugs. To improve light absorption, laser radiation is combined with different dyes. Photodynamic therapy, originally used in oncology, is applied today in treating different diseases. We showed a possibility of using a number of drugs possessing simultaneously photosensitizing properties to this end. Laser radiation significantly influences pharmacokinetics and pharmacodynamics of drugs, which gives reason to practically implement laser technologies, based on pharmacomodulating action of laser radiation, to practical medicine.

Optimizing Results of Postmastectomy Radiation Therapy Utilizing the Latissimus Dorsi Flap and Tissue Expander Technique: A Single-Center Experience

PubMed Central

Chevrollier, Guillaume S.; Greaney, Patrick J.; Jenkins, Matthew P.; Copit, Steven E.

2017-01-01

Objective: Postmastectomy radiation therapy is a well-established risk factor for complications after breast reconstruction. Even if the surgeon has a suspicion that radiation therapy may be needed, it may be beneficial to place tissue expanders during the mastectomy procedure as a temporizing measure, complete radiation therapy, and then reconstruct the breast with a latissimus flap. The purpose of this study was to examine the complication rates of the latissimus dorsi flap as compared with the complication rates of implant-based reconstruction in the setting of radiation therapy. Methods: A 16-year retrospective chart review from 2000 to 2016 was conducted. All patients who underwent temporizing tissue expander placement for radiotherapy with subsequent latissimus flap reconstruction were included in the study. Patients who did not follow up for implant exchange were excluded from the study. Results: Fifty-five patients were identified with an average age of 46.0 years (range, 27-67 years) and an average body mass index of 24.2 (range, 18.9-31.9). Five patients (9.1%) developed capsular contractures amenable to surgical intervention. One patient (1.8%) developed infection of the tissue expander, requiring removal. There were no incidences of flap failure or wound dehiscence. The average follow-up after latissimus flap reconstruction was 25.3 months (range, 3.7-121.6 months). Conclusions: We feel that the latissimus dorsi flap after postmastectomy radiation therapy represents the preferred implant-based reconstruction option to consider when the need for postmastectomy radiation therapy is anticipated. The latissimus dorsi flap remains a safe, effective solution to postmastectomy radiation therapy that every plastic surgeon should offer. PMID:29308108

Optimizing Results of Postmastectomy Radiation Therapy Utilizing the Latissimus Dorsi Flap and Tissue Expander Technique: A Single-Center Experience.

PubMed

Mohiuddin, Waseem; Chevrollier, Guillaume S; Greaney, Patrick J; Jenkins, Matthew P; Copit, Steven E

2017-01-01

Objective: Postmastectomy radiation therapy is a well-established risk factor for complications after breast reconstruction. Even if the surgeon has a suspicion that radiation therapy may be needed, it may be beneficial to place tissue expanders during the mastectomy procedure as a temporizing measure, complete radiation therapy, and then reconstruct the breast with a latissimus flap. The purpose of this study was to examine the complication rates of the latissimus dorsi flap as compared with the complication rates of implant-based reconstruction in the setting of radiation therapy. Methods: A 16-year retrospective chart review from 2000 to 2016 was conducted. All patients who underwent temporizing tissue expander placement for radiotherapy with subsequent latissimus flap reconstruction were included in the study. Patients who did not follow up for implant exchange were excluded from the study. Results: Fifty-five patients were identified with an average age of 46.0 years (range, 27-67 years) and an average body mass index of 24.2 (range, 18.9-31.9). Five patients (9.1%) developed capsular contractures amenable to surgical intervention. One patient (1.8%) developed infection of the tissue expander, requiring removal. There were no incidences of flap failure or wound dehiscence. The average follow-up after latissimus flap reconstruction was 25.3 months (range, 3.7-121.6 months). Conclusions: We feel that the latissimus dorsi flap after postmastectomy radiation therapy represents the preferred implant-based reconstruction option to consider when the need for postmastectomy radiation therapy is anticipated. The latissimus dorsi flap remains a safe, effective solution to postmastectomy radiation therapy that every plastic surgeon should offer.

Novel technologies and theoretical models in radiation therapy of cancer patients using 6.3 MeV fast neutrons produced by U-120 cyclotron

DOE Office of Scientific and Technical Information (OSTI.GOV)

Musabaeva, L. I., E-mail: musabaevaLI@oncology.tomsk.ru; Lisin, V. A., E-mail: Lisin@oncology.tomsk.ru; Startseva, Zh. A., E-mail: zhanna.alex@rambler.ru

The analysis of clinical use of neutron therapy with 6 MeV fast neutrons compared to conventional radiation therapy was carried out. The experience of using neutron and mixed neutron and photon therapy in patients with different radio-resistant malignant tumors shows the necessity of further studies and development of the novel approaches to densely-ionizing radiation. The results of dosimetry and radiobiological studies have been the basis for planning clinical programs for neutron therapy. Clinical trials over the past 30 years have shown that neutron therapy successfully destroys radio-resistant cancers, including salivary gland tumors, adenoidcystic carcinoma, inoperable sarcomas, locally advanced head andmore » neck tumors, and locally advanced prostate cancer. Radiation therapy with 6.3 MeV fast neutrons used alone and in combination with photon therapy resulted in improved long-term treatment outcomes in patients with radio-resistant malignant tumors.« less

Effect of Tendon Vibration on Hemiparetic Arm Stability in Unstable Workspaces.

PubMed

Conrad, Megan O; Gadhoke, Bani; Scheidt, Robert A; Schmit, Brian D

2015-01-01

Sensory stimulation of wrist musculature can enhance stability in the proximal arm and may be a useful therapy aimed at improving arm control post-stroke. Specifically, our prior research indicates tendon vibration can enhance stability during point-to-point arm movements and in tracking tasks. The goal of the present study was to investigate the influence of forearm tendon vibration on endpoint stability, measured at the hand, immediately following forward arm movements in an unstable environment. Both proximal and distal workspaces were tested. Ten hemiparetic stroke subjects and 5 healthy controls made forward arm movements while grasping the handle of a two-joint robotic arm. At the end of each movement, the robot applied destabilizing forces. During some trials, 70 Hz vibration was applied to the forearm flexor muscle tendons. 70 Hz was used as the stimulus frequency as it lies within the range of optimal frequencies that activate the muscle spindles at the highest response rate. Endpoint position, velocity, muscle activity and grip force data were compared before, during and after vibration. Stability at the endpoint was quantified as the magnitude of oscillation about the target position, calculated from the power of the tangential velocity data. Prior to vibration, subjects produced unstable, oscillating hand movements about the target location due to the applied force field. Stability increased during vibration, as evidenced by decreased oscillation in hand tangential velocity.

Effect of Tendon Vibration on Hemiparetic Arm Stability in Unstable Workspaces

PubMed Central

Conrad, Megan O.; Gadhoke, Bani; Scheidt, Robert A.; Schmit, Brian D.

2015-01-01

Sensory stimulation of wrist musculature can enhance stability in the proximal arm and may be a useful therapy aimed at improving arm control post-stroke. Specifically, our prior research indicates tendon vibration can enhance stability during point-to-point arm movements and in tracking tasks. The goal of the present study was to investigate the influence of forearm tendon vibration on endpoint stability, measured at the hand, immediately following forward arm movements in an unstable environment. Both proximal and distal workspaces were tested. Ten hemiparetic stroke subjects and 5 healthy controls made forward arm movements while grasping the handle of a two-joint robotic arm. At the end of each movement, the robot applied destabilizing forces. During some trials, 70 Hz vibration was applied to the forearm flexor muscle tendons. 70 Hz was used as the stimulus frequency as it lies within the range of optimal frequencies that activate the muscle spindles at the highest response rate. Endpoint position, velocity, muscle activity and grip force data were compared before, during and after vibration. Stability at the endpoint was quantified as the magnitude of oscillation about the target position, calculated from the power of the tangential velocity data. Prior to vibration, subjects produced unstable, oscillating hand movements about the target location due to the applied force field. Stability increased during vibration, as evidenced by decreased oscillation in hand tangential velocity. PMID:26633892

Partial breast radiation therapy - external beam

MedlinePlus

APBI is used to prevent breast cancer from coming back. When radiation therapy is given after breast- ... breast conservation therapy reduces the risk of cancer coming back, and possibly even death from breast cancer.

Redox-Modulated Phenomena and Radiation Therapy: The Central Role of Superoxide Dismutases

PubMed Central

Holley, Aaron K.; Miao, Lu; St. Clair, Daret K.

2014-01-01

Abstract Significance: Ionizing radiation is a vital component in the oncologist's arsenal for the treatment of cancer. Approximately 50% of all cancer patients will receive some form of radiation therapy as part of their treatment regimen. DNA is considered the major cellular target of ionizing radiation and can be damaged directly by radiation or indirectly through reactive oxygen species (ROS) formed from the radiolysis of water, enzyme-mediated ROS production, and ROS resulting from altered aerobic metabolism. Recent Advances: ROS are produced as a byproduct of oxygen metabolism, and superoxide dismutases (SODs) are the chief scavengers. ROS contribute to the radioresponsiveness of normal and tumor tissues, and SODs modulate the radioresponsiveness of tissues, thus affecting the efficacy of radiotherapy. Critical Issues: Despite its prevalent use, radiation therapy suffers from certain limitations that diminish its effectiveness, including tumor hypoxia and normal tissue damage. Oxygen is important for the stabilization of radiation-induced DNA damage, and tumor hypoxia dramatically decreases radiation efficacy. Therefore, auxiliary therapies are needed to increase the effectiveness of radiation therapy against tumor tissues while minimizing normal tissue injury. Future Directions: Because of the importance of ROS in the response of normal and cancer tissues to ionizing radiation, methods that differentially modulate the ROS scavenging ability of cells may prove to be an important method to increase the radiation response in cancer tissues and simultaneously mitigate the damaging effects of ionizing radiation on normal tissues. Altering the expression or activity of SODs may prove valuable in maximizing the overall effectiveness of ionizing radiation. Antioxid. Redox Signal. 20, 1567–1589. PMID:24094070

Systematic review of hyperbaric oxygen therapy for the treatment of radiation-induced skin necrosis.

PubMed

Borab, Zachary; Mirmanesh, Michael D; Gantz, Madeleine; Cusano, Alessandro; Pu, Lee L Q

2017-04-01

Every year, 1.2 million cancer patients receive radiation therapy in the United States. Late radiation tissue injury occurs in an estimated 5-15% of these patients. Tissue injury can include skin necrosis, which can lead to chronic nonhealing wounds. Despite many treatments available to help heal skin necrosis such as hyperbaric oxygen therapy, no clinical guidelines exist and evidence is lacking. The purpose of this review is to identify and comprehensively summarize studies published to date to evaluate the effectiveness of hyperbaric oxygen therapy for the treatment of radiation-induced skin necrosis. Adhering to PRISMA guidelines, a systematic review of currently published articles was performed, evaluating the use of hyperbaric oxygen to treat skin necrosis. Eight articles were identified, including one observational cohort, five case series, and two case reports. The articles describe changes in symptoms and alteration in wound healing of radiation-induced skin necrosis after treatment with hyperbaric oxygen therapy. Hyperbaric oxygen therapy is a safe intervention with promising outcomes; however, additional evidence is needed to endorse its application as a relevant therapy in the treatment of radiation-induced skin necrosis. Copyright © 2016 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

Hyperbaric oxygen therapy for the treatment of radiation-induced xerostomia: a systematic review.

PubMed

Fox, Nyssa F; Xiao, Christopher; Sood, Amit J; Lovelace, Tiffany L; Nguyen, Shaun A; Sharma, Anand; Day, Terry A

2015-07-01

Radiation-induced xerostomia is one of the most common morbidities of radiation therapy in patients with head and neck cancer. However, in spite of its high rate of occurrence, there are few effective therapies available for its management. The aim of this study was to assess the efficacy of hyperbaric oxygen on the treatment of radiation-induced xerostomia and xerostomia-related quality of life. PubMed, Google Scholar, and the Cochrane Library were searched for retrospective or prospective trials assessing subjective xerostomia, objective xerostomia, or xerostomia-related quality of life. To be included, patients had to have received radiation therapy for head and neck cancer, but not hyperbaric oxygen therapy (HBOT). The systematic review initially identified 293 potential articles. Seven studies, comprising 246 patients, qualified for inclusion. Of the included studies, 6 of 7 were prospective in nature, and 1 was a retrospective study; and 2 of the 7 were controlled studies. HBOT may have utility for treating radiation-induced xerostomia refractory to other therapies. Additionally, HBOT may induce long-term improvement in subjective assessments of xerostomia, whereas other therapies currently available only provide short-term relief. The strength of these conclusions is limited by the lack of randomized controlled clinical trials. Copyright © 2015 Elsevier Inc. All rights reserved.

A Modified EPA Method 1623 that Uses Tangential Flow Hollow-Fiber Ultrafiltration and Heat Dissociation Steps to Detect Waterborne Cryptosporidum and Giardia spp.

EPA Science Inventory

This protocol describes the use of a tangential flow hollow-fiber ultrafiltration sample concentration system and a heat dissociation as alternative steps for the detection of waterborne Cryptosporidium and Giardia species using EPA Method 1623.

INVESTIGATION OF CONVENTIONAL MEMBRANE AND TANGENTIAL FLOW ULTRAFILTRATION ARTIFACTS AND THEIR APPLICATION TO THE CHARACTERIZATION OF FRESHWATER COLLOIDS

EPA Science Inventory

Artifacts associated with the fractionation of colloids in a freshwater sample were investigated for conventional membrane filtration (0.45 micron cutoff), and two tangential flow ultrafiltration cartridges (0.1 micron cutoff and 3000 MW cutoff). Membrane clogging during conventi...

Aeroacoustic Duster

NASA Technical Reports Server (NTRS)

Marshall, Jeffrey S. (Inventor); Chen, Di (Inventor); Vachon, Nicholas Mario (Inventor); Hitt, Darren (Inventor); Wu, Junru (Inventor)

2014-01-01

The aero-acoustic duster invention disclosed herein provides for high particle removal rate from surfaces with low energy expenditure relative to competing vacuum-based devices. The device removes particulate matter from a surface using a two-step process: 1. Acoustic radiation is used to break the adhesive bonds between dust and the surface, forcing particles into a mode where they continuously bounce up and down on the surface; and, 2. A bounded vortex is generated over the surface, with suction in the vortex center and jets for blowing air along the periphery. The jets are tilted in the tangential direction to induce vortex motion within the suction region. The vortex is said to be bounded because streamlines originating in the downward jets are entrained back into the central vortex.

Surface waves with high angular momentum: leakage from remote caustics, and tightly coiled streamlines

NASA Astrophysics Data System (ADS)

Berry, M. V.

2018-07-01

Outgoing cylindrical waves scattered by a disk, or emerging from a source inside it, are represented by Hankel functions of order m. For large m, these waves decay rapidly outside the disk and resemble radially evanescent surface waves travelling around it. But they eventually leak weakly away, in a manner described accurately by the asymptotics of the Hankel function. The transition occurs at radial distance ∣m∣ (in wavelength units), which constitutes a circular caustic from which the radiation leaking out, described by the streamlines, appears to issue tangentially. In the evanescent region, the streamlines form spirals, whose windings get exponentially closer nearer the disk. These insights are intended to help graduate students demystify mathematics associated with scattering theory.

Observation of runaway electrons by infrared camera in J-TEXT

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tong, R. H.; Chen, Z. Y., E-mail: zychen@hust.edu.cn; Zhang, M.

2016-11-15

When the energy of confined runaway electrons approaches several tens of MeV, the runaway electrons can emit synchrotron radiation in the range of infrared wavelength. An infrared camera working in the wavelength of 3-5 μm has been developed to study the runaway electrons in the Joint Texas Experimental Tokamak (J-TEXT). The camera is located in the equatorial plane looking tangentially into the direction of electron approach. The runaway electron beam inside the plasma has been observed at the flattop phase. With a fast acquisition of the camera, the behavior of runaway electron beam has been observed directly during the runawaymore » current plateau following the massive gas injection triggered disruptions.« less

Response of melanoma to heat and radiation therapy--a review of the literature and experience from The Prince of Wales Hospital, Sydney.

PubMed

Mameghan, H; Knittel, T

1988-11-07

Our review of the literature indicates that radiotherapy and/or heat therapy can provide local control of recurrent or metastatic melanoma in a large proportion of patients. This has undoubted value in the local palliation of symptoms and, in the absence of disseminated disease, can be curative. At The Prince of Wales Hospital, Sydney, we have studied the response of melanoma lesions to heat and radiation therapy and have assessed the reaction in the adjacent normal skin. Thirty-two melanoma lesions that were measurable in 12 patients received radiotherapy and heat therapy in different combinations and dose schedules (15 lesions received radiotherapy alone, six lesions received heat therapy alone, and 11 lesions received combined radiation and heat therapy). The acute normal skin reaction was compared between lesions that received single modality radiation or heat therapy and those that received the combination of heat and radiation therapy. A moderate or severe reaction developed at six of the 21 sites that were treated by a single modality, and at four of the 11 sites that received combined heat and radiation therapy (P = 0.7), and all healed within a few days. Evaluation of the melanoma response to therapy was possible only in 26 of the 32 lesions that were treated because two patients died soon after therapy and the response of their six lesions was not evaluable. A complete response occurred in 14 (54%) of 26 lesions and a partial response occurred in 10 (38%) of 26 lesions. The objective response by treatment modality was 10 of 15 lesions for radiotherapy, six of six lesions for heat therapy and eight of 11 lesions for both therapies combined. We conclude that radiotherapy and heat therapy, separately or combined, produce acceptably-low damage to normal tissue and highly-satisfactory local control of melanoma.

Successful management of lichen myxedematosus

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hill, T.F.; Crawford, J.N.; Rogers, C.C.

1976-01-01

Radiation therapy led to local resolution of a case of lichen myxedematosus, which, to our knowledge, is the first reported successful treatment of the disease by radiation therapy. Radiation therapy is only the second therapeutic modality that is effective in the treatment of lichen myxedematosus. We propose specific criteria for the diagnosis of lichen myxedematosus to facilitate future studies into the nature of this disease. (auth)

Radiation Therapy for Locally Advanced Esophageal Cancer.

PubMed

Chun, Stephen G; Skinner, Heath D; Minsky, Bruce D

2017-04-01

The treatment of locally advanced esophageal cancer is controversial. For patients who are candidates for surgical resection, multiple prospective clinical trials have demonstrated the advantages of neoadjuvant chemoradiation. For patients who are medically inoperable, definitive chemoradiation is an alternative approach with survival rates comparable to trimodality therapy. Although trials of dose escalation are ongoing, the standard radiation dose remains 50.4 Gy. Modern radiotherapy techniques such as image-guided radiation therapy with motion management and intensity-modulated radiation therapy are strongly encouraged with a planning objective to maximize conformity to the intended target volume while reducing dose delivered to uninvolved normal tissues. Copyright © 2016 Elsevier Inc. All rights reserved.

[Role of locoregional radiation therapy in breast cancer patients with negative lymph nodes after preoperative chemotherapy and mastectomy. The Institut Curie-Hôpital René-Huguenin experience].

PubMed

Le Scodan, R; Bruant, S; Selz, J; Bollet, M-A; Daveau, C; de la Lande, B; Lerebours, F; Labib, A; Stevens, D

2011-12-01

Neoadjuvant chemotherapy generally induces significant changes in the pathological extent of disease and challenges the standard indications of adjuvant postmastectomy radiation therapy. We retrospectively evaluated the impact of postmastectomy radiation therapy in breast cancer patients with negative lymph nodes (pN0) after neoadjuvant chemotherapy. Among 1054 breast cancer patients treated with neoadjuvant chemotherapy in our institution between 1990 and 2004, 134 patients had pN0 status after neoadjuvant chemotherapy and mastectomy. Demographic data, tumor characteristics, metastatic sites, and treatments were prospectively recorded. The impact of postmastectomy radiation therapy on locoregional recurrence-free survival and overall survival was evaluated by multivariate analysis including known prognostic factors. Among 134 eligible patients, 78 patients (58.2%) received postmastectomy radiation therapy, and 56 patients (41.8%) did not. With a median follow-up time of 91.4 months, the 10-year locoregional recurrence-free survival and overall survival rates were 96.2% and 77.2% with postmastectomy radiation therapy and 86.8% and 87.7% without radiation therapy, respectively (no significant difference). In multivariate analysis, there was a trend towards poorer overall survival among patients who did not have a pathologically complete primary tumour response after neoadjuvant chemotherapy (hazard ratio [HR], 6.65; 95% CI, 0.82-54.12; P=0.076). Postmastectomy radiation therapy had no effect on either locoregional recurrence-free survival (HR, 0.37; 95% CI, 0.09-1.61; P=0.18) or overall survival (HR, 2.06; 95% CI, 0.71-6; P=0.18). There was a trend towards poorer overall survival among patients who did not have pathologically complete in-breast tumour response after neoadjuvant chemotherapy (HR, 6.65; 95% CI, 0.82-54.12; P=0.076). This retrospective study showed no increase in the risk of distant metastasis, locoregional recurrence or death when postmastectomy radiation therapy was omitted in breast cancer patients with pN0 status after neoadjuvant chemotherapy and mastectomy. Whether the omission of postmastectomy radiation therapy is acceptable for these patients should be addressed prospectively. Copyright © 2011 Société française de radiothérapie oncologique (SFRO). Published by Elsevier SAS. All rights reserved.

Integrating Multimodal Radiation Therapy Data into i2b2.

PubMed

Zapletal, Eric; Bibault, Jean-Emmanuel; Giraud, Philippe; Burgun, Anita

2018-04-01

 Clinical data warehouses are now widely used to foster clinical and translational research and the Informatics for Integrating Biology and the Bedside (i2b2) platform has become a de facto standard for storing clinical data in many projects. However, to design predictive models and assist in personalized treatment planning in cancer or radiation oncology, all available patient data need to be integrated into i2b2, including radiation therapy data that are currently not addressed in many existing i2b2 sites.  To use radiation therapy data in projects related to rectal cancer patients, we assessed the feasibility of integrating radiation oncology data into the i2b2 platform.  The Georges Pompidou European Hospital, a hospital from the Assistance Publique - Hôpitaux de Paris group, has developed an i2b2-based clinical data warehouse of various structured and unstructured clinical data for research since 2008. To store and reuse various radiation therapy data-dose details, activities scheduling, and dose-volume histogram (DVH) curves-in this repository, we first extracted raw data by using some reverse engineering techniques and a vendor's application programming interface. Then, we implemented a hybrid storage approach by combining the standard i2b2 "Entity-Attribute-Value" storage mechanism with a "JavaScript Object Notation (JSON) document-based" storage mechanism without modifying the i2b2 core tables. Validation was performed using (1) the Business Objects framework for replicating vendor's application screens showing dose details and activities scheduling data and (2) the R software for displaying the DVH curves.  We developed a pipeline to integrate the radiation therapy data into the Georges Pompidou European Hospital i2b2 instance and evaluated it on a cohort of 262 patients. We were able to use the radiation therapy data on a preliminary use case by fetching the DVH curve data from the clinical data warehouse and displaying them in a R chart.  By adding radiation therapy data into the clinical data warehouse, we were able to analyze radiation therapy response in cancer patients and we have leveraged the i2b2 platform to store radiation therapy data, including detailed information such as the DVH to create new ontology-based modules that provides research investigators with a wider spectrum of clinical data. Schattauer GmbH Stuttgart.

Stadium IB - IIA cervical cancer patient’s survival rate after receiving definitive radiation and radical operation therapy followed by adjuvant radiation therapy along with analysis of factors affecting the patient’s survival rate

NASA Astrophysics Data System (ADS)

Ruslim, S. K.; Purwoto, G.; Widyahening, I. S.; Ramli, I.

2017-08-01

To evaluate the characteristics and overall survival rates of early stage cervical cancer (FIGO IB-IIA) patients who receive definitive radiation therapy and those who are prescribed adjuvant postoperative radiation and to conduct a factors analysis of the variables that affect the overall survival rates in both groups of therapy. The medical records of 85 patients with cervical cancer FIGO stages IB-IIA who were treated at the Department of Radiotherapy of Cipto Mangunkusumo Hospital were reviewed and analyzed to determine their overall survival and the factors that affected it between a definitive radiation group and an adjuvant postoperative radiation group. There were 25 patients in the definitive radiation and 60 patients in the adjuvant radiation group. The overall survival rates in the adjuvant radiation group at years one, two, and three were 96.7%, 95%, and 93.3%, respectively. Negative lymph node metastasis had an average association with overall survival (p < 0.2). In the definitive radiation group, overall survival at years one, two, and three were 96%, 92%, and 92%, respectively. A hemoglobin (Hb) level >12 g/dl was a factor with an average association with the overall survival (p < 0.2). The differences between both groups of therapy were not statistically significant (92% vs. 93.3%; p = 0.138). This study did not show any statistically significant overall survival for cervical cancer FIGO stage IB-IIA patients who received definitive radiation or adjuvant postoperative radiation. Negative lymph node metastasis had an effect on the overall survival rate in the adjuvant postoperative radiation group, while a preradiation Hb level >12 g/dl tended to affect the overall survival in the definitive radiation group patients.

Once-Daily Radiation Therapy for Inflammatory Breast Cancer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brown, Lindsay; Harmsen, William; Blanchard, Miran

2014-08-01

Purpose: Inflammatory breast cancer (IBC) is a rare and aggressive breast cancer variant treated with multimodality therapy. A variety of approaches intended to escalate the intensity and efficacy of radiation therapy have been reported, including twice-daily radiation therapy, dose escalation, and aggressive use of bolus. Herein, we examine our outcomes for patients treated with once-daily radiation therapy with aggressive bolus utilization, focusing on treatment technique. Methods and Materials: A retrospective review of patients with nonmetastatic IBC treated from January 1, 2000, through December 31, 2010, was performed. Locoregional control (LRC), disease-free survival (DFS), overall survival (OS) and predictors thereof weremore » assessed. Results: Fifty-two women with IBC were identified, 49 (94%) of whom were treated with neoadjuvant chemotherapy. All underwent mastectomy followed by adjuvant radiation therapy. Radiation was delivered in once-daily fractions of 1.8 to 2.25 Gy (median, 2 Gy). Patients were typically treated with daily 1-cm bolus throughout treatment, and 33 (63%) received a subsequent boost to the mastectomy scar. Five-year Kaplan Meier survival estimates for LRC, DFS, and OS were 81%, 56%, and 64%, respectively. Locoregional recurrence was associated with poorer OS (P<.001; hazard ratio [HR], 4.1). Extracapsular extension was associated with worse LRC (P=.02), DFS (P=.007), and OS (P=.002). Age greater than 50 years was associated with better DFS (P=.03). Pathologic complete response was associated with a trend toward improved LRC (P=.06). Conclusions: Once-daily radiation therapy with aggressive use of bolus for IBC results in outcomes consistent with previous reports using various intensified radiation therapy regimens. LRC remains a challenge despite modern systemic therapy. Extracapsular extension, age ≤50 years, and lack of complete response to chemotherapy appear to be associated with worse outcomes. Novel strategies are needed in IBC, particularly among these subsets of patients.« less

Quality of Life of Patients with Spinal Metastasis from Cancer of Unknown Primary Origin: A Longitudinal Study of Surgical Management Combined with Postoperative Radiation Therapy.

PubMed

Ma, Yifei; He, Shaohui; Liu, Tielong; Yang, Xinghai; Zhao, Jian; Yu, Hongyu; Feng, Jiaojiao; Xu, Wei; Xiao, Jianru

2017-10-04

Patients with spinal metastasis from cancer of unknown primary origin have limited life expectancy and poor quality of life. Surgery and radiation therapy remain the main treatment options, but, to our knowledge, there are limited data concerning quality-of-life improvement after surgery and radiation therapy and even fewer data on whether surgical intervention would affect quality of life. Patients were enrolled between January 2009 and January 2014 at the Changzheng Hospital, Shanghai, People's Republic of China. The quality of life of 2 patient groups (one group that underwent surgery followed by postoperative radiation therapy and one group that underwent radiation therapy only) was assessed by the Functional Assessment of Cancer Therapy-General (FACT-G) questionnaire during a 6-month period. A subgroup analysis of quality of life was performed to compare different surgical strategies in the surgical group. A total of 287 patients, including 191 patients in the group that underwent surgery and 96 patients in the group that underwent radiation therapy only, were enrolled in the prospective study; 177 patients completed all 5 checkpoints and 110 patients had died by the final checkpoint. The surgery group had significantly higher adjusted quality-of-life scores than the radiation therapy group in each domain of the FACT-G questionnaire (all p < 0.05). Subgroup analysis showed that adjusted functional and physical well-being scores were higher in the circumferential surgical decompression group. Surgery followed by postoperative radiation therapy improved and maintained quality of life in patients with spinal metastasis from cancer of unknown primary origin in the 6-month assessment. In terms of surgical strategies, circumferential decompression seems better than laminectomy alone in quality-of-life improvement. Therapeutic Level II. See Instructions for Authors for a complete description of levels of evidence.

78 FR 43281 - Medicare Program; Revisions to Payment Policies under the Physician Fee Schedule, Clinical...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-07-19

..., Independent Laboratory, Pathology, Radiation Oncology, and Radiation Therapy Centers are projected to have a... Mass immunization roster biller. 74 Radiation therapy centers. 87 All other suppliers (e.g., drug and...

Radiation Therapy

MedlinePlus

... cancer patients receive it. The radiation may be external, from special machines, or internal, from radioactive substances that a doctor places inside your body. The type of radiation therapy you receive depends on many factors, including The type of cancer The size of ...

Utilization of surgery, chemotherapy, radiation therapy, and hospice at the end of life for patients diagnosed with metastatic melanoma.

PubMed

Huo, Jinhai; Du, Xianglin L; Lairson, David R; Chan, Wenyaw; Jiang, Jing; Buchholz, Thomas A; Guadagnolo, B Ashleigh

2015-06-01

To examine the patterns of utilization of radiation therapy, chemotherapy, surgery, and hospice at the end-of-life care for patients diagnosed with metastatic melanoma. We identified 816 Medicare beneficiaries toward who were 65 years of age or older, with pathologically confirmed metastatic malignant melanoma between January 1, 2000, and December 31, 2007. We evaluated trends and associations between sociodemographic and health service characteristics and the use of hospice care, chemotherapy, surgery, and radiation therapy. We found increasing use of surgery for patients with metastatic melanoma from 13% in 2000 to 30% in 2007 (P=0.03 for trend), and no significant fluctuation in the use of chemotherapy (P=0.43) or radiation therapy (P=0.46). Older patients were less likely to receive radiation therapy or chemotherapy. The use of hospice care increased from 61% in 2000 to 79% in 2007 (P=0.07 for trend). Enrollment in short-term (1 to 3 d) hospice care use increased, whereas long-term hospice care (≥4 d) remained stable. Patients living in the SEER (Surveillance, Epidemiology and End Results) northeast and south regions were less likely to undergo surgery. Patients enrolled in long-term hospice care used significantly less chemotherapy, surgery, and radiation therapy. Surgery and hospice care use increased over the years of this study, whereas the use of chemotherapy and radiation therapy remained consistent for patients diagnosed with metastatic melanoma.

Ceiling art in a radiation therapy department: its effect on patient treatment experience

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bonett, Jotham

A new initiative has been implemented at the Sunshine Hospital Radiation Therapy Centre, to provide a calming and comforting environment for patients attending radiation therapy treatment. As part of this initiative, the department's computed tomography (CT) room and radiation therapy bunkers were designed to incorporate ceiling art that replicates a number of different visual scenes. The study was undertaken to determine if ceiling art in the radiation therapy treatment CT and treatment bunkers had an effect on a patient's experience during treatment at the department. Additionally, the study aimed to identify which of the visuals in the ceiling art weremore » most preferred by patients. Patients were requested to complete a 12-question survey. The survey solicited a patient's opinion/perception on the unit's unique ceiling display with emphasis on aesthetic appeal, patient treatment experience and the patient's engagement due to the ceiling display. The responses were dichotomised to ‘positive’ or ‘negative’. Every sixth patient who completed the survey was invited to have a general face-to-face discussion to provide further information about their thoughts on the displays. The results demonstrate that the ceiling artwork solicited a positive reaction in 89.8% of patients surveyed. This score indicates that ceiling artwork contributed positively to patients’ experiences during radiation therapy treatment. The study suggests that ceiling artwork in the department has a positive effect on patient experience during their radiation therapy treatment at the department.« less

Comfort and quality of life in patients with breast cancer undergoing radiation therapy.

PubMed

Pehlivan, Seda; Kuzhan, Abdurrahman; Yildirim, Yasemin; Fadiloglu, Cicek

2016-01-01

Radiation therapy is generally applied after surgery for the treatment of breast cancer, which is among the most frequently observed types of cancer in females. Radiation therapy may have some negative effects on the quality of life due to various side effects such as changes in the skin, mucositis and fatigue. Our study was planned as a descriptive study, in order to examine the relationship between comfort and quality of life in breast cancer patients undergoing radiation therapy. This study involved 61 patients with breast cancer undergoing radiation therapy. Data were collected using "Patient Information Form", "Radiation Therapy Comfort Questionnaire" and "EORTC QLQ-BR23". The scales were applied twice, before the start and at the end of treatment. Data were evaluated via Wilcoxon test and Spearman correlation analyses. No statistically significant difference was determined between comfort and quality of life average score before and after radiotherapy (p>0.05). A positive relationship was determined between the pain and symptom quality of life (p<0.05). Although a positive relationship was determined between comfort score and the functional and general quality of life areas, a negative relationship was detected with the symptom quality of life (p<0.01). Radiation therapy applied to breast cancer patients did not affect comfort and quality of life, On the contrary, the quality of life of patients increased along with their comfort levels and that comfort levels decreased as the experienced symptoms increased.

[The effectiveness of magnetic therapy of grade I-II radiation pneumofibrosis].

PubMed

Grushina, T I

2014-01-01

Radiation therapy of malignant tumours of the chest organs may result in radiation damage of the lungs. To prevent and reduce radiation-induced lung injuries, new types of radiation therapy have been developed, a number of various modifiers investigated, the methods of pharmacotherapy and physiotherapy proposed. The present study involved 37 patients presenting with radiation pneumofibrosis, including 7 ones with lung cancer and 30 patients with breast cancer. Based on the results of clinical, radiographic, and functional investigations, grade 1 and II pneumofibrosis was diagnosed in 20 and 17 patients respectively. After the application of an alternating magnetic field during 15 days, all the patients experience the overall regression of clinical symptoms and disorders of respiratory biomechanics. However, it seems premature to draw a definitive conclusion about the effectiveness of magnetic therapy of grade 1 and II radiation pneumofibrosis before the extensive in-depth investigations are carried out based on a large clinical material including the results of long-term follow-up studies and continuous monitoring.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ogo, Etsuyo; Komaki, Ritsuko; Fujimoto, Kiminori

Purpose: We observed a rare and unique occurrence of radiation-induced pulmonary injury outside the tangential field for early breast cancer treatment. The findings appeared to be idiopathic and were called radiation-induced bronchiolitis obliterans organizing pneumonia (BOOP) syndrome. We surveyed major hospitals in Japan to review their findings of radiation-induced BOOP, in particular the clinical and pictorial characteristics of the entity. Methods and Materials: We reviewed surveys completed and returned by 20 institutions. The survey responses were based on a total of 37 cases of BOOP syndrome. We also reviewed X-ray and computed tomography scans provided by these institutions. We discussedmore » the information derived from the questionnaire and analyzed patients' characteristics, methods used in the treatment of BOOP syndrome, and prognosis. Results: The incidence of the radiation-induced BOOP syndrome was about 1.8% (37 of 2,056). We did not find a relationship between the characteristics of patients and the occurrence of radiation-induced BOOP syndrome. The pulmonary findings were classified into four patterns on chest computed tomography scans. Progression of the pulmonary lesions observed on chest X-ray was classified into three patterns. Pneumonitis appeared within 6 months after radiotherapy was completed and disappeared within 6-12 months after its onset. At 5-year follow-up, 2 patients had died, 1 of breast cancer and the other of interstitial pneumonitis, which seemed to be idiopathic and unrelated to the radiation-induced BOOP syndrome. Conclusions: Although the incidence of BOOP syndrome and its associated prognosis are not significant, the patients' clinical condition must be carefully followed.« less

Heat Models of Asteroids and the YORP Effect

NASA Astrophysics Data System (ADS)

Golubov, O.

The Yarkovsky-O'Keefe-Radzievski-Paddack (YORP) effect is a torque of light pressure recoil forces acting on an asteroid. We show how this torque can be expressed as an integral of a universal function over the surface of an asteroid, and discuss generalizations of this expression for the case of non-Lambert's scattering laws, non-convex shapes of asteroids, and non-zero heat conductivity. Then we discuss tangential YORP (TYORP), which appears due to uneven heat conductivity in stones lying on the surface of an asteroid. TYORP manifests itself as a drag, which pulls the surface in the tangential direction. Finally, we discuss relation and interplay between the normal YORP and the tangential YORP.

Droplet condensation on superhydrophobic surfaces with enhanced dewetting under a tangential AC electric field

NASA Astrophysics Data System (ADS)

Yan, Xinzhu; Li, Jian; Li, Licheng; Huang, Zhengyong; Wang, Feipeng; Wei, Yuan

2016-10-01

In this Letter, the dewetting behavior of superhydrophobic condensing surfaces under a tangential AC electric field is reported. The surface coverage of condensed droplets only exhibits a negligible increase with time. The jumping frequency of droplets is enhanced. The AC electric field motivates the dynamic transition of droplets from stretch to recoil, resulting in the counterforce propelling droplet jumping. The considerable horizontal component of jumping velocity facilitates droplet departure from superhydrophobic surfaces. Both the amplitude and frequency of AC voltage are important factors for droplet departure and dewetting effect. Thereby, the tangential electric field provides a unique and easily implementable approach to enhance droplet removal from superhydrophobic condensing surfaces.

Salvage treatment for recurrent oropharyngeal squamous cell carcinoma.

PubMed

Röösli, Christof; Studer, Gabriela; Stoeckli, Sandro J

2010-08-01

This study evaluates the oncological outcome of patients with recurrent oropharyngeal squamous cell carcinoma (OPSCC) after primary radiation therapy +/- chemotherapy, primary surgical therapy, and surgical therapy followed by radiation therapy +/- chemotherapy. A total of 156 patients (36%) of a cohort of 427 treated for OPSCC between 1990 and 2006 developed recurrent disease. Fifty-one patients (12%) qualified for salvage treatment. Study endpoints were 5-year overall survival (OS) and disease-specific survival (DSS). The 5-year OS and DSS rates after salvage treatment were 29% and 40%; after initial primary radiation therapy, 25% and 40%; after initial surgery followed by radiation therapy, 40% and 40%; and after initial surgery alone, 20% and 40%. Patients with an advanced OPSCC have a considerable risk for recurrence. Despite poor ultimate outcome, salvage treatment should be attempted in patients with resectable disease, good performance status, and absence of distant metastases. 2009 Wiley Periodicals, Inc. Head Neck, 2010.

Mometasone Furoate Cream Reduces Acute Radiation Dermatitis in Patients Receiving Breast Radiation Therapy: Results of a Randomized Trial

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hindley, Andrew, E-mail: andrew.hindley@lthtr.nhs.uk; Zain, Zakiyah; Wood, Lisa

Purpose: We wanted to confirm the benefit of mometasone furoate (MF) in preventing acute radiation reactions, as shown in a previous study (Boström et al, Radiother Oncol 2001;59:257-265). Methods and Materials: The study was a double-blind comparison of MF with D (Diprobase), administered daily from the start of radiation therapy for 5 weeks in patients receiving breast radiation therapy, 40 Gy in 2.67-Gy fractions daily over 3 weeks. The primary endpoint was mean modified Radiation Therapy Oncology Group (RTOG) score. Results: Mean RTOG scores were significantly less for MF than for D (P=.046). Maximum RTOG and mean erythema scores were significantly less for MFmore » than for D (P=.018 and P=.012, respectively). The Dermatology Life Quality Index (DLQI) score was significantly less for MF than for D at weeks 4 and 5 when corrected for Hospital Anxiety and Depression (HAD) questionnaire scores. Conclusions: MF cream significantly reduces radiation dermatitis when applied to the breast during and after radiation therapy. For the first time, we have shown a significantly beneficial effect on quality of life using a validated instrument (DLQI), for a topical steroid cream. We believe that application of this cream should be the standard of care where radiation dermatitis is expected.« less

Appetite and adverse effects associated with radiation therapy in patients with head and neck cancer.

PubMed

Ogama, Norimasa; Suzuki, Sumie; Umeshita, Koji; Kobayashi, Tamami; Kaneko, Shoko; Kato, Sakiko; Shimizu, Yasuko

2010-02-01

The relationship between radiation treatment and adverse effects resulting in changes in appetite was studied in patients with head and neck (H&N) cancer. Path analysis was used to evaluate the following factors in 117 patients receiving radiation therapy for H&N cancer: daily fluctuations in saliva production, analgesic use, frequency of oral care, subject characteristics, and appetite. At 20 Gy of radiation, appetite was affected by Brinkman index value, age, and sensitivity to taste (R2=0.48, p<0.001); at 30 Gy of radiation, appetite was affected by frequency of oral care, xerostomia symptoms, age, sensitivity to taste, and oral mucositis (R2=0.52, p<0.001); and at 50 Gy of radiation, appetite was affected by low saliva production in the morning, frequency of oral care, xerostomia symptoms, sensitivity to taste, analgesic use, and oral mucositis (R2=0.62, p<0.001). The results of this study suggest that care taken to avoid a decrease in appetite due to adverse effects of radiation therapy should differ according to the dosage and schedule of radiation therapy. These findings represent important data for health care professionals to understand and support appropriate dietary intake and improved quality of life for H&N cancer patients receiving radiation therapy. Copyright 2009 Elsevier Ltd. All rights reserved.

Efficient computation of coherent synchrotron radiation in a rectangular chamber

NASA Astrophysics Data System (ADS)

Warnock, Robert L.; Bizzozero, David A.

2016-09-01

We study coherent synchrotron radiation (CSR) in a perfectly conducting vacuum chamber of rectangular cross section, in a formalism allowing an arbitrary sequence of bends and straight sections. We apply the paraxial method in the frequency domain, with a Fourier development in the vertical coordinate but with no other mode expansions. A line charge source is handled numerically by a new method that rids the equations of singularities through a change of dependent variable. The resulting algorithm is fast compared to earlier methods, works for short bunches with complicated structure, and yields all six field components at any space-time point. As an example we compute the tangential magnetic field at the walls. From that one can make a perturbative treatment of the Poynting flux to estimate the energy deposited in resistive walls. The calculation was motivated by a design issue for LCLS-II, the question of how much wall heating from CSR occurs in the last bend of a bunch compressor and the following straight section. Working with a realistic longitudinal bunch form of r.m.s. length 10.4 μ m and a charge of 100 pC we conclude that the radiated power is quite small (28 W at a 1 MHz repetition rate), and all radiated energy is absorbed in the walls within 7 m along the straight section.

Does the presence of an implant including expander with internal port alter radiation dose? An ex vivo model.

PubMed

Strang, Barbara; Murphy, Kyla; Seal, Shane; Cin, Arianna Dal

2013-01-01

There is a lack of literature examining the dosimetric implications of irradiating breast implants and expanders with internal ports inserted at the time of mastectomy. To determine whether the presence of breast expanders with port in saline or silicone implants affect the dose uniformity across the breast when irradiated with various photon and electron energies. One tissue-equivalent torso phantom with overlying tissue expanders in saline or silicone implants were irradiated using tangential fields with 6 MV and 18 MV photons and 9 MeV and 12 MeV electrons. All dose measurements were performed using thermoluminescent dosimeters (TLDs). The TLDs were arranged around the port and the perimeters of either the expander, or saline or silicone implant. Comparisons of measured radiation doses, and between the expected and measured doses of radiation from the TLDs on each prosthesis, were performed. Data were analyzed using two-tailed t tests. There were no differences in TLD measurements between the expander and the saline implant for all energy modalities, and for the expected versus actual measurements for the saline implant. Higher than anticipated measurements were recorded for a significant number of TLD positions around the silicone implants. Radiation doses around saline implants or expanders with internal port were unaltered, whereas dose recordings for silicone implants were higher than predicted in the present laboratory/ex vivo study.

Imaging and Data Acquisition in Clinical Trials for Radiation Therapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

FitzGerald, Thomas J., E-mail: Thomas.Fitzgerald@umassmed.edu; Bishop-Jodoin, Maryann; Followill, David S.

2016-02-01

Cancer treatment evolves through oncology clinical trials. Cancer trials are multimodal and complex. Assuring high-quality data are available to answer not only study objectives but also questions not anticipated at study initiation is the role of quality assurance. The National Cancer Institute reorganized its cancer clinical trials program in 2014. The National Clinical Trials Network (NCTN) was formed and within it was established a Diagnostic Imaging and Radiation Therapy Quality Assurance Organization. This organization is Imaging and Radiation Oncology Core, the Imaging and Radiation Oncology Core Group, consisting of 6 quality assurance centers that provide imaging and radiation therapy qualitymore » assurance for the NCTN. Sophisticated imaging is used for cancer diagnosis, treatment, and management as well as for image-driven technologies to plan and execute radiation treatment. Integration of imaging and radiation oncology data acquisition, review, management, and archive strategies are essential for trial compliance and future research. Lessons learned from previous trials are and provide evidence to support diagnostic imaging and radiation therapy data acquisition in NCTN trials.« less

Alterations of nutritional status: impact of chemotherapy and radiation therapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Donaldson, S.S.; Lenon, R.A.

1979-05-01

The nutritional status of a cancer patient may be affected by the tumor, the chemotherapy and/or radiation therapy directed against the tumor, and by complications associated with that therapy. Chemotherpay-radiotherapy is not confined exclusively to malignant cell populations; thus, normal tissues may also be affected by the therapy and may contribute to specific nutritional problems. Impaired nutrition due to anorexia, mucositis, nausea, vomiting, and diarrhea may be dependent upon the specific chemotherapeutic agent, dose, or schedule utilized. Similar side effects from radiation therapy depend upon the dose, fractionation, and volume irradiated. When combined modality treatment is given the nutritional consequencesmore » may be magnified. Prospective, randomized clinical trials are underway to investigate the efficacy of nutritional support during chemotherapy-radiotherapy on tolerance to treatment, complications from treatment, and response rates to treatment. Preliminary results demonstrate that the administration of total parenteral nutrition is successful in maintaining weight during radiation therapy and chemotherapy, but that weight loss occurs after discontinuation of nutritional support. Thus, longterm evaluation is mandatory to learn the impact of nutritional support on survival, diease-free survival, and complication rates, as well as on the possible prevention of morbidity associated with aggressive chemotherapy-radiation therapy.« less

Inhibition of mTOR enhances radiosensitivity of lung cancer cells and protects normal lung cells against radiation.

PubMed

Zheng, Hang; Wang, Miao; Wu, Jing; Wang, Zhi-Ming; Nan, Hai-Jun; Sun, He

2016-06-01

Radiotherapy has been used for a long time as a standard therapy for cancer; however, there have been no recent research breakthroughs. Radioresistance and various side-effects lead to the unexpected outcomes of radiation therapy. Specific and accurate targeting as well as reduction of radioresistance have been major challenges for irradiation therapy. Recent studies have shown that rapamycin shows promise for inhibiting tumorigenesis by suppressing mammalian target of rapamycin (mTOR). We found that the combination of rapamycin with irradiation significantly diminished cell viability and colony formation, and increased cell apoptosis, as compared with irradiation alone in lung cancer cell line A549, suggesting that rapamycin can enhance the effectiveness of radiation therapy by sensitizing cancer cells to irradiation. Importantly, we observed that the adverse effects of irradiation on a healthy lung cell line (WI-38) were also offset. No enhanced protein expression of mTOR signaling was observed in WI-38 cells, which is normally elevated in lung cancer cells. Moreover, DNA damage was significantly less with the combination therapy than with irradiation therapy alone. Our data suggest that the incorporation of rapamycin during radiation therapy could be a potent way to improve the sensitivity and effectiveness of radiation therapy as well as to protect normal cells from being damaged by irradiation.

Clinical Outcomes of Image Guided Adaptive Hypofractionated Weekly Radiation Therapy for Bladder Cancer in Patients Unsuitable for Radical Treatment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hafeez, Shaista, E-mail: shaista.hafeez@icr.ac.uk; The Royal Marsden NHS Foundation Trust, Sutton, Surrey; McDonald, Fiona

Purpose and Objectives: We report on the clinical outcomes of a phase 2 study assessing image guided hypofractionated weekly radiation therapy in bladder cancer patients unsuitable for radical treatment. Methods and Materials: Fifty-five patients with T2-T4aNx-2M0-1 bladder cancer not suitable for cystectomy or daily radiation therapy treatment were recruited. A “plan of the day” radiation therapy approach was used, treating the whole (empty) bladder to 36 Gy in 6 weekly fractions. Acute toxicity was assessed weekly during radiation therapy, at 6 and 12 weeks using the Common Terminology Criteria for Adverse Events version 3.0. Late toxicity was assessed at 6 months and 12 monthsmore » using Radiation Therapy Oncology Group grading. Cystoscopy was used to assess local control at 3 months. Cumulative incidence function was used to determine local progression at 1 at 2 years. Death without local progression was treated as a competing risk. Overall survival was estimated using the Kaplan-Meier method. Results: Median age was 86 years (range, 68-97 years). Eighty-seven percent of patients completed their prescribed course of radiation therapy. Genitourinary and gastrointestinal grade 3 acute toxicity was seen in 18% (10/55) and 4% (2/55) of patients, respectively. No grade 4 genitourinary or gastrointestinal toxicity was seen. Grade ≥3 late toxicity (any) at 6 and 12 months was seen in 6.5% (2/31) and 4.3% (1/23) of patients, respectively. Local control after radiation therapy was 92% of assessed patients (60% total population). Cumulative incidence of local progression at 1 year and 2 years for all patients was 7% (95% confidence interval [CI] 2%-17%) and 17% (95% CI 8%-29%), respectively. Overall survival at 1 year was 63% (95% CI 48%-74%). Conclusion: Hypofractionated radiation therapy delivered weekly with a plan of the day approach offers good local control with acceptable toxicity in a patient population not suitable for radical bladder treatment.« less

Adjuvant Hypofractionated Versus Conventional Whole Breast Radiation Therapy for Early-Stage Breast Cancer: Long-Term Hospital-Related Morbidity From Cardiac Causes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chan, Elisa K.; Woods, Ryan; McBride, Mary L.

Purpose: The risk of cardiac injury with hypofractionated whole-breast/chest wall radiation therapy (HF-WBI) compared with conventional whole-breast/chest wall radiation therapy (CF-WBI) in women with left-sided breast cancer remains a concern. The purpose of this study was to determine if there is an increase in hospital-related morbidity from cardiac causes with HF-WBI relative to CF-WBI. Methods and Materials: Between 1990 and 1998, 5334 women ≤80 years of age with early-stage breast cancer were treated with postoperative radiation therapy to the breast or chest wall alone. A population-based database recorded baseline patient, tumor, and treatment factors. Hospital administrative records identified baseline cardiacmore » risk factors and other comorbidities. Factors between radiation therapy groups were balanced using a propensity-score model. The first event of a hospital admission for cardiac causes after radiation therapy was determined from hospitalization records. Ten- and 15-year cumulative hospital-related cardiac morbidity after radiation therapy was estimated for left- and right-sided cases using a competing risk approach. Results: The median follow-up was 13.2 years. For left-sided cases, 485 women were treated with CF-WBI, and 2221 women were treated with HF-WBI. Mastectomy was more common in the HF-WBI group, whereas boost was more common in the CF-WBI group. The CF-WBI group had a higher prevalence of diabetes. The 15-year cumulative hospital-related morbidity from cardiac causes (95% confidence interval) was not different between the 2 radiation therapy regimens after propensity-score adjustment: 21% (19-22) with HF-WBI and 21% (17-25) with CF-WBI (P=.93). For right-sided cases, the 15-year cumulative hospital-related morbidity from cardiac causes was also similar between the radiation therapy groups (P=.76). Conclusions: There is no difference in morbidity leading to hospitalization from cardiac causes among women with left-sided early-stage breast cancer treated with HF-WBI or CF-WBI at 15-year follow-up.« less

Tangential Flow Filtration of Colloidal Silver Nanoparticles: A "Green" Laboratory Experiment for Chemistry and Engineering Students

ERIC Educational Resources Information Center

Dorney, Kevin M.; Baker, Joshua D.; Edwards, Michelle L.; Kanel, Sushil R.; O'Malley, Matthew; Pavel Sizemore, Ioana E.

2014-01-01

Numerous nanoparticle (NP) fabrication methodologies employ "bottom-up" syntheses, which may result in heterogeneous mixtures of NPs or may require toxic capping agents to reduce NP polydispersity. Tangential flow filtration (TFF) is an alternative "green" technique for the purification, concentration, and size-selection of…

Improved design of a tangential entry cyclone separator for separation of particles from exhaust gas of diesel engine.

PubMed

Mukhopadhyay, N

2011-01-01

An effective design of cyclone separator with tangential inlet is developed applying an equation derived from the correlation of collection efficiency with maximum pressure drop components of the cyclone, which can efficiently remove the particles around 1microm of the exhaust gas of diesel engine.

Rationale and Application of Tangential Scanning to Industrial Inspection of Hardwood Logs

Treesearch

Nand K. Gupta; Daniel L. Schmoldt; Bruce Isaacson

1998-01-01

Industrial computed tomography (CT) inspection of hardwood logs has some unique requirements not found in other CT applications. Sawmill operations demand that large volumes of wood be scanned quickly at high spatial resolution for extended duty cycles. Current CT scanning geometries and commercial systems have both technical and economic [imitations. Tangential...

An investigation of factors affecting wettability of some southern hardwoods

Treesearch

Todd F. Shupe; Chung Y. Hse; Wan H. Wang

1999-01-01

>Wettability of sanded and nonsanded transverse and tangential sections of 22 southern hardwood species were[was] judged by measurement of contact angles using phenol-formaldehyde resins. As ex­pected, contact angle values on transverse sec­tions were higher than on tangential sections for both sanded and...

An investigation of selected factors that influence hardwood wettability

Treesearch

Todd F. Shupe; Chung-Yun Hse; Wan H. Wang

2001-01-01

Wettability of sanded and non-sanded transverse and tangential sections of 22 southern hardwoods species was judged by measurement of contact angles using phenol formaldehyde resins. As expected, contact angle values on transverse sections were higher than those on tangential sections for both sanded and non-sanded surfaces. On sanded surfaces, hackberry had the...

Soft lubrication

NASA Astrophysics Data System (ADS)

Skotheim, Jan; Mahadevan, Laksminarayanan

2004-11-01

We study the lubrication of fluid-immersed soft interfaces and show that elastic deformation couples tangential and normal forces and thus generates lift. We consider materials that deform easily, due to either geometry (e.g a shell) or constitutive properties (e.g. a gel or a rubber), so that the effects of pressure and temperature on the fluid properties may be neglected. Four different system geometries are considered: a rigid cylinder moving tangentially to a soft layer coating a rigid substrate; a soft cylinder moving tangentially to a rigid substrate; a cylindrical shell moving tangentially to a rigid substrate; and finally a journal bearing coated with a thin soft layer, which being a conforming contact allows us to gauge the influence of contact geometry. In addition, for the particular case of a soft layer coating a rigid substrate we consider both elastic and poroelastic material responses. Finally, we consider the role of contact geometry in the context of the journal bearing, a conforming contact. For all these cases we find the same generic behavior: there is an optimal combination of geometric and material parameters that maximizes the dimensionless normal force as a function of the softness.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dillon, C.

Over the past few years, numerous Accreditation Bodies, Regulatory Agencies, and State Regulations have implemented requirements for Radiation Safety Surveys following installation or modification to x-ray rooms. The objective of this session is to review best practices in performing radiation safety surveys for both Therapy and Diagnostic installations, as well as a review of appropriate survey instruments. This session will be appropriate for both therapy and imaging physicists who are looking to increase their working knowledge of radiation safety surveys. Learning Objectives: Identify Appropriate Survey Meters for Radiation Safety Surveys Develop best practices for Radiation Safety Surveys for Therapy unitsmore » that include common areas of concern. Develop best practices for Radiation Safety Surveys of Diagnostic and Nuclear Medicine rooms. Identify acceptable dose levels and the factors that affect the calculations associated with performing Radiation Safety Surveys.« less

Long-Term Effects of Radiation Exposure among Adult Survivors of Childhood Cancer: Results from the Childhood Cancer Survivor Study

PubMed Central

Armstrong, Gregory T.; Stovall, Marilyn; Robison, Leslie L.

2010-01-01

In the last four decades, advances in therapies for primary cancers have improved overall survival for childhood cancer. Currently, almost 80% of children will survive beyond 5 years from diagnosis of their primary malignancy. These improved outcomes have resulted in a growing population of childhood cancer survivors. Radiation therapy, while an essential component of primary treatment for many childhood malignancies, has been associated with risk of long-term adverse outcomes. The Childhood Cancer Survivor Study (CCSS), a retrospective cohort of over 14,000 survivors of childhood cancer diagnosed between 1970 and 1986, has been an important resource to quantify associations between radiation therapy and risk of long-term adverse health and quality of life outcomes. Radiation therapy has been associated with increased risk for late mortality, development of second neoplasms, obesity, and pulmonary, cardiac and thyroid dysfunction as well as an increased overall risk for chronic health conditions. Importantly, the CCSS has provided more precise estimates for a number of dose–response relationships, including those for radiation therapy and development of subsequent malignant neoplasms of the central nervous system, thyroid and breast. Ongoing study of childhood cancer survivors is needed to establish long-term risks and to evaluate the impact of newer techniques such as conformal radiation therapy or proton-beam therapy. PMID:21128808

Further studies on cortical tangential migration in wild type and Pax-6 mutant mice.

PubMed

Jiménez, D; López-Mascaraque, L; de Carlos, J A; Valverde, F

2002-01-01

In this study we present new data concerning the tangential migration from the medial and lateral ganglionic eminences (MGE and LGE) to the cerebral cortex during development. We have used Calbindin as a useful marker to follow the itinerary of tangential migratory cells during early developmental stages in wild-type and Pax-6 homozygous mutant mice. In the wild-type mice, at early developmental stages, migrating cells advance through the intermediate zone (IZ) and preplate (PP). At more advanced stages, migrating cells were present in the subplate (SP) and cortical plate (CP) to reach the entire developing cerebral cortex. We found that, in the homozygous mutant mice (Pax-6(Sey-Neu)/Pax-6(Sey-Neu)), this tangential migration is severely affected at early developmental stages: migrating cells were absent in the IZ, which were only found some days later, suggesting that in the mutant mice, there is a temporal delay in tangential migration. We have also defined some possible mechanisms to explain certain migratory routes from the basal telencephalon to the cerebral cortex. We describe the existence of two factors, which we consider to be essential for the normal migration; the first one is the cell adhesion molecule PSA-NCAM, whose role in other migratory systems is well known. The second factor is Robo-2, whose expression delimits a channel for the passage of migratory cells from the basal telencephalon to the cerebral cortex.

A technique for treating local breast cancer using a single set-up point and asymmetric collimation.

PubMed

Rosenow, U F; Valentine, E S; Davis, L W

1990-07-01

Using both pairs of asymmetric jaws of a linear accelerator local-regional breast cancer may be treated from a single set-up point. This point is placed at the abutment of the supraclavicular fields with the medial and lateral tangential fields. Positioning the jaws to create a half-beam superiorly permits treatment of the supraclavicular field. Positioning both jaws asymmetrically at midline to define a single beam in the inferoanterior quadrant permits treatment of the breast from medial and lateral tangents. The highest possible matching accuracy between the supraclavicular and tangential fields is inherently provided by this technique. For treatment of all fields at 100 cm source to axis distance (SAD) the lateral placement and depth of the set-up point may be determined by simulation and simple trigonometry. We elaborate on the clinical procedure. For the technologists treatment of all fields from a single set-up point is simple and efficient. Since the tissue at the superior border of the tangential fields is generally firmer than in mid-breast, greater accuracy in day-to-day set-up is permitted. This technique eliminates the need for table angles even when tangential fields only are planned. Because of half-beam collimation the limit to the tangential field length is 20 cm. Means will be suggested to overcome this limitation in the few cases where it occurs. Another modification is suggested for linear accelerators with only one independent pair of jaws.

Graft-versus-host disease after radiation therapy in patients who have undergone allogeneic stem cell transplantation: two case reports.

PubMed

Milgrom, Sarah A; Nieto, Yago; Pinnix, Chelsea C; Smith, Grace L; Wogan, Christine F; Rondon, Gabriela; Medeiros, L Jeffrey; Kebriaei, Partow; Dabaja, Bouthaina S

2016-07-28

Patients who undergo allogeneic stem cell transplantation and subsequent radiation therapy uncommonly develop graft-versus-host disease within the irradiated area. We quantified the incidence of this complication, which is a novel contribution to the field. From 2010 to 2014, 1849 patients underwent allogeneic stem cell transplantation, and 41 (2 %) received radiation therapy afterward. Of these, two patients (5 %) developed graft-versus-host disease within the irradiated tissues during or immediately after radiation therapy. The first patient is a 37-year-old white man who had Hodgkin lymphoma; he underwent allogeneic stem cell transplantation from a matched unrelated donor and received radiation therapy for an abdominal and pelvic nodal recurrence. After 28.8 Gy, he developed grade 4 gastrointestinal graft-versus-host disease, refractory to tacrolimus and steroids, but responsive to pentostatin and photopheresis. The other patient is a 24-year-old white man who had acute leukemia; he underwent allogeneic stem cell transplantation from a matched related donor and received craniospinal irradiation for a central nervous system relapse. After 24 cobalt Gy equivalent, he developed severe cutaneous graft-versus-host disease, sharply delineated within the radiation therapy field, which was responsive to tacrolimus and methylprednisolone. We conclude that graft-versus-host disease within irradiated tissues is an uncommon but potentially serious complication that may follow radiation therapy in patients who have undergone allogeneic stem cell transplantation. Clinicians must be aware of this complication and prepared with strategies to mitigate risk. Patients who have undergone allogeneic stem cell transplantation represent a unique population that may offer novel insight into the pathways involved in radiation-related inflammation.

Metal artifacts in computed tomography for radiation therapy planning: dosimetric effects and impact of metal artifact reduction.

PubMed

Giantsoudi, Drosoula; De Man, Bruno; Verburg, Joost; Trofimov, Alexei; Jin, Yannan; Wang, Ge; Gjesteby, Lars; Paganetti, Harald

2017-04-21

A significant and increasing number of patients receiving radiation therapy present with metal objects close to, or even within, the treatment area, resulting in artifacts in computed tomography (CT) imaging, which is the most commonly used imaging method for treatment planning in radiation therapy. In the presence of metal implants, such as dental fillings in treatment of head-and-neck tumors, spinal stabilization implants in spinal or paraspinal treatment or hip replacements in prostate cancer treatments, the extreme photon absorption by the metal object leads to prominent image artifacts. Although current CT scanners include a series of correction steps for beam hardening, scattered radiation and noisy measurements, when metal implants exist within or close to the treatment area, these corrections do not suffice. CT metal artifacts affect negatively the treatment planning of radiation therapy either by causing difficulties to delineate the target volume or by reducing the dose calculation accuracy. Various metal artifact reduction (MAR) methods have been explored in terms of improvement of organ delineation and dose calculation in radiation therapy treatment planning, depending on the type of radiation treatment and location of the metal implant and treatment site. Including a brief description of the available CT MAR methods that have been applied in radiation therapy, this article attempts to provide a comprehensive review on the dosimetric effect of the presence of CT metal artifacts in treatment planning, as reported in the literature, and the potential improvement suggested by different MAR approaches. The impact of artifacts on the treatment planning and delivery accuracy is discussed in the context of different modalities, such as photon external beam, brachytherapy and particle therapy, as well as by type and location of metal implants.

Metal artifacts in computed tomography for radiation therapy planning: dosimetric effects and impact of metal artifact reduction

NASA Astrophysics Data System (ADS)

Giantsoudi, Drosoula; De Man, Bruno; Verburg, Joost; Trofimov, Alexei; Jin, Yannan; Wang, Ge; Gjesteby, Lars; Paganetti, Harald

2017-04-01

A significant and increasing number of patients receiving radiation therapy present with metal objects close to, or even within, the treatment area, resulting in artifacts in computed tomography (CT) imaging, which is the most commonly used imaging method for treatment planning in radiation therapy. In the presence of metal implants, such as dental fillings in treatment of head-and-neck tumors, spinal stabilization implants in spinal or paraspinal treatment or hip replacements in prostate cancer treatments, the extreme photon absorption by the metal object leads to prominent image artifacts. Although current CT scanners include a series of correction steps for beam hardening, scattered radiation and noisy measurements, when metal implants exist within or close to the treatment area, these corrections do not suffice. CT metal artifacts affect negatively the treatment planning of radiation therapy either by causing difficulties to delineate the target volume or by reducing the dose calculation accuracy. Various metal artifact reduction (MAR) methods have been explored in terms of improvement of organ delineation and dose calculation in radiation therapy treatment planning, depending on the type of radiation treatment and location of the metal implant and treatment site. Including a brief description of the available CT MAR methods that have been applied in radiation therapy, this article attempts to provide a comprehensive review on the dosimetric effect of the presence of CT metal artifacts in treatment planning, as reported in the literature, and the potential improvement suggested by different MAR approaches. The impact of artifacts on the treatment planning and delivery accuracy is discussed in the context of different modalities, such as photon external beam, brachytherapy and particle therapy, as well as by type and location of metal implants.

3-D Waveform Modeling of the 11 September 2001 World Trade Center Collapse Events in New York City

NASA Astrophysics Data System (ADS)

Yoo, S.; Rhie, J.; Kim, W.

2010-12-01

The seismic signals from collapse of the twin towers of World Trade Center (WTC), NYC were well recorded by the seismographic stations in the northeastern United States. The building collapse can be represented by a vertical single force which does not generate tangential component seismic signals during the source process. The waveforms recorded by the Basking Ridge, NJ (BRNJ) station located due west of the WTC site show that the amplitude on tangential component is negligible and indicates that a vertical single force assumption is valid and the velocity structure is more or less homogeneous along the propagation path. However, 3-component seismograms recorded at Palisades, NY (PAL), which is located 33.8 km due north of the WTC site along the Hudson River (azimuth = 15.2°), show abnormal features. The amplitude on tangential component is larger than on vertical- or on radial-component. This observation may be attributable to the complex energy conversion between Rayleigh and Love waves due to the strong low velocity anomaly associated with unconsolidated sediments under the Hudson River. To test the effects of the low velocity anomaly on the enhanced amplitude in tangential component, we developed a 3D velocity model by considering local geology such as unconsolidated sediment layer, Palisades sill, Triassic sandstone, and crystalline basement and simulated waveforms at PAL. The preliminary synthetic results show that 3D velocity structure can significantly enhance the amplitude in tangential component but it is not as large as the observation. Although a more precise 3D model is required to better explain the observations, our results confirm that the low velocity layer under the Hudson River can enhance the amplitude in tangential component at PAL. This result suggests that a good understanding of the amplitude enhancements for specific event-site pairs may be important to evaluate seismic hazard of metropolitan New York City.

Mesenchymal stem cell therapy for acute radiation syndrome.

PubMed

Fukumoto, Risaku

2016-01-01

Acute radiation syndrome affects military personnel and civilians following the uncontrolled dispersal of radiation, such as that caused by detonation of nuclear devices and inappropriate medical treatments. Therefore, there is a growing need for medical interventions that facilitate the improved recovery of victims and patients. One promising approach may be cell therapy, which, when appropriately implemented, may facilitate recovery from whole body injuries. This editorial highlights the current knowledge regarding the use of mesenchymal stem cells for the treatment of acute radiation syndrome, the benefits and limitations of which are under investigation. Establishing successful therapies for acute radiation syndrome may require using such a therapeutic approach in addition to conventional approaches.

Poster — Thur Eve — 10: Partial kV CBCT, complete kV CBCT and EPID in breast treatment: a dose comparison study for skin, breasts, heart and lungs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Roussin, E; Archambault, L K; Wierzbicki, W

The advantages of kilovoltage cone beam CT (kV CBCT) imaging over electronic portal imaging device (EPID) such as accurate 3D anatomy, soft tissue visualization, fast rigid registration and enhanced precision on patient positioning has lead to its increasing use in clinics. The benefits of this imaging technique are at the cost of increasing the dose to healthy surrounding organs. Our center has moved toward the use of daily partial rotation kV CBCT to restrict the dose to healthy tissues. This study aims to better quantify radiation doses from different image-guidance techniques such as tangential EPID, complete and partial kV CBCTmore » for breast treatments. Cross-calibrated ionization chambers and kV calibrated Gafchromic films were used to measure the dose to the heart, lungs, breasts and skin. It was found that performing partial kV CBCT decreases the heart dose by about 36%, the lungs dose by 31%, the contralateral breast dose by 41% and the ipsilateral breast dose by 43% when compared to a full rotation CBCT. The skin dose measured for a full rotation CBCT was about 0.8 cGy for the contralateral breast and about 0.3 cGy for the ipsilateral breast. The study is still ongoing and results on skin doses for partial rotation kV CBCT as well as for tangential EPID images are upcoming.« less

A Fast Visible Camera Divertor-Imaging Diagnostic on DIII-D

DOE Office of Scientific and Technical Information (OSTI.GOV)

Roquemore, A; Maingi, R; Lasnier, C

2007-06-19

In recent campaigns, the Photron Ultima SE fast framing camera has proven to be a powerful diagnostic when applied to imaging divertor phenomena on the National Spherical Torus Experiment (NSTX). Active areas of NSTX divertor research addressed with the fast camera include identification of types of EDGE Localized Modes (ELMs)[1], dust migration, impurity behavior and a number of phenomena related to turbulence. To compare such edge and divertor phenomena in low and high aspect ratio plasmas, a multi-institutional collaboration was developed for fast visible imaging on NSTX and DIII-D. More specifically, the collaboration was proposed to compare the NSTX smallmore » type V ELM regime [2] and the residual ELMs observed during Type I ELM suppression with external magnetic perturbations on DIII-D[3]. As part of the collaboration effort, the Photron camera was installed recently on DIII-D with a tangential view similar to the view implemented on NSTX, enabling a direct comparison between the two machines. The rapid implementation was facilitated by utilization of the existing optics that coupled the visible spectral output from the divertor vacuum ultraviolet UVTV system, which has a view similar to the view developed for the divertor tangential TV camera [4]. A remote controlled filter wheel was implemented, as was the radiation shield required for the DIII-D installation. The installation and initial operation of the camera are described in this paper, and the first images from the DIII-D divertor are presented.« less

a High-Frequency Three-Dimensional Tyre Model Based on Two Coupled Elastic Layers

NASA Astrophysics Data System (ADS)

LARSSON, K.; KROPP, W.

2002-06-01

Road traffic noise is today a serious environmental problem in urban areas. The dominating noise source at speeds greater than 50 km/h is car tyres. In order to achieve a reduction of traffic noise tyres have to become quieter. To reduce tyre/road noise a deep understanding of the noise generation mechanisms is of major importance. An existing tyre/road noise simulation model consists of a smooth tyre rolling at a constant speed on a rough road surface. It is composed of three separate modules: a tyre model, a contact model and a radiation model. The major drawback with the contact model is that it only takes the radial component of the contact forces into account. To improve this model, a description of the tangential motion at high frequencies is necessary. Most of the models for the structure-borne sound behaviour of tyres are designed for the low-frequency range (i.e., below 400 Hz). Above this frequency range, the curvature of the tyre is unimportant, while the internal structure (multi-layers of steel and rubber) increases in importance. For the high-frequency range, a double-layer tyre model is proposed, which is based on the general field equations, to take into account the tangential motion and the local deformation of the tread. Both propagating waves and mode shapes have been investigated by the use of this model. Calculations of the response of the tyre to an external excitation show relatively good agreement with measurements on a smooth tyre.

A novel imaging approach for prostate cancer is tested in new clinical trial | Center for Cancer Research

Cancer.gov

Prostate cancer patients who have failed standard radiation therapy have the options of surgery, radioactive seed implantation or cryoablation. Deborah Citrin, M.D., of the Radiation Oncology Branch is leading a study of stereotactic body radiation therapy (SBRT) to treat prostate cancer that has recurred locally after standard radiation therapy. The goal of this study is to use a novel imaging approach to guide treatment and to define the best dose of SBRT for patients whose prostate cancer has recurred after standard radiotherapy. Read more...

Intervention quality is not routinely assessed in Cochrane systematic reviews of radiation therapy interventions.

PubMed

Abdul Rahim, Mohamad R; James, Melissa L; Hickey, Brigid E

2017-10-01

The aim of this study was to maximise the benefits from clinical trials involving technological interventions such as radiation therapy. High compliance to the quality assurance protocols is crucial. We assessed whether the quality of radiation therapy intervention was evaluated in Cochrane systematic reviews. We searched 416 published Cochrane systematic reviews and identified 67 Cochrane systematic reviews that investigated radiation therapy or radiotherapy as an intervention. For each systematic review, either quality assurance or quality control for the intervention was identified by a description of such processes in the published systematic reviews. Of the 67 Cochrane systematic reviews studied, only two mentioned quality assurance or quality control. Our findings revealed that 65 of 67 (97%) Cochrane systematic reviews of radiation therapy interventions failed to consider the quality of the intervention. We suggest that advice about the evaluation of intervention quality be added to author support materials. © 2017 The Royal Australian and New Zealand College of Radiologists.

De novo development of a cerebral arteriovenous malformation following radiation therapy: Case report and an update to classical arteriovenous malformation nomenclature.

PubMed

Koch, Matthew J; Agarwalla, Pankaj K; Stapleton, Christopher J; Ogilvy, Christopher S; Loeffler, Jay S

2016-06-01

Cerebral arteriovenous malformations (AVM) are traditionally considered primary congenital lesions that result from embryological aberrations in vasculogenesis. Recent insights, however, suggest that these lesions may be secondary to a vascular insult such as ischemia or trauma. Herein, the authors present a rare case of a secondary cerebral AVM, occurring in a young girl who received prior cranial radiation therapy. At age 3years, she underwent surgical resection, chemotherapy, and photon radiation therapy for treatment of a fourth ventricular ependymoma. At age 19years, she developed new onset seizures and was found to have a left medial temporal lobe AVM. Her seizures were managed successfully with anti-epileptic medications and the AVM was treated with proton radiation therapy. This case highlights a rare but possible vascular sequela of radiation therapy and adds to the growing body of evidence that cerebral AVM may arise as secondary lesions. Copyright © 2015 Elsevier Ltd. All rights reserved.

Positron Emission Tomography/Computed Tomography Findings During Therapy Predict Outcome in Patients With Diffuse Large B-Cell Lymphoma Treated With Chemotherapy Alone but Not in Those Who Receive Consolidation Radiation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dabaja, Bouthaina S., E-mail: bdabaja@mdanderson.org; Hess, Kenneth; Shihadeh, Ferial

2014-06-01

Purpose: To assess the value of mid-therapy positron emission tomography (PET) findings for predicting survival and disease progression in patients with diffuse large B-cell lymphoma, considering type of therapy (chemotherapy with or without radiation therapy). Methods and Materials: We retrospectively evaluated 294 patients with histologically confirmed diffuse large B-cell lymphoma with respect to age, sex, disease stage, International Prognostic Index score, mid-therapy PET findings (positive or negative), and disease status after therapy and at last follow-up. Overall survival (OS) and progression-free survival (PFS) were compared according to mid-therapy PET findings. Results: Of the 294 patients, 163 (55%) were male, 144more » (49%) were age >61 years, 110 (37%) had stage I or II disease, 219 (74%) had International Prognostic Index score ≤2, 216 (73%) received ≥6 cycles of rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone, and 88 (30%) received consolidation radiation therapy. Five-year PFS and OS rates were associated with mid-therapy PET status: PFS was 78% for those with PET-negative (PET−) disease versus 63% for PET-positive (PET+) disease (P=.024), and OS was 82% for PET− versus 62% for PET+ (P<.002). These associations held true for patients who received chemotherapy only (PFS 71% for PET− vs 52% PET+ [P=.012], OS 78% for PET− and 51% for PET+ [P=.0055]) but not for those who received consolidation radiation therapy (PFS 84% PET− vs 81% PET+ [P=.88]; OS 90% PET− vs 81% PET+ [P=.39]). Conclusion: Mid-therapy PET can predict patient outcome, but the use of consolidation radiation therapy may negate the significance of mid-therapy findings.« less

Prediction of iodine-131 biokinetics and radiation doses from therapy on the basis of tracer studies: an important question for therapy planning in nuclear medicine.

PubMed

Willegaignon, José; Pelissoni, Rogério A; Lima, Beatriz C G D; Sapienza, Marcelo T; Coura-Filho, George B; Buchpiguel, Carlos A

2016-05-01

This study aimed to present a comparison of iodine-131 (I) biokinetics and radiation doses to red-marrow (rm) and whole-body (wb), following the administration of tracer and therapeutic activities, as a means of confirming whether I clearance and radiation doses for therapy procedures can be predicted by tracer activities. Eleven differentiated thyroid cancer patients were followed after receiving tracer and therapeutic I activity. Whole-body I clearance was estimated using radiation detectors and OLINDA/EXM software was used to calculate radiation doses to rm and wb. Tracer I activity of 86 (±14) MBq and therapeutic activity of 8.04 (±1.18) GBq were administered to patients, thereby producing an average wb I effective half-time and residence time of, respectively, 13.51 (±4.05) and 23.13 (±5.98) h for tracer activities and 13.32 (±3.38) and 19.63 (±4.77) h for therapy. Radiation doses to rm and wb were, respectively, 0.0467 (±0.0208) and 0.0589 (±0.0207) mGy/MBq in tracer studies and 0.0396 (±0.0169) and 0.0500 (±0.0163) mGy/MBq in therapy. Although the differences were not considered statistically significant between averages, those between the values of effective half-times (P=0.906), residence times (P=0.145), and radiation doses to rm (P=0.393) and to wb (P=0.272), from tracer and therapy procedures, large differences of up to 80% in wb I clearance, and up to 50% in radiation doses were observed when patients were analyzed individually, thus impacting on the total amount of I activity calculated to be safe for application in individual therapy. I biokinetics and radiation doses to rm and wb in therapy procedures are well predicted by diagnostic activities when average values of a group of patients are compared. Nonetheless, when patients are analyzed individually, significant differences may be encountered, thus implying that nuclear medicine therapy-planning requires due consideration of changes in individual patient-body status from initial tracer to final therapy procedures to thus provide appropriate adjustments in therapeutic activities.

Finger's amniotic membrane buffer technique: protecting the cornea during radiation plaque therapy.

PubMed

Finger, Paul T

2008-04-01

To use amniotic membranes as a buffer between the cornea and radioactive eye plaques. Six melanomas were treated with ophthalmic plaque radiation therapy. Plaque-tumor localization required that a portion of the gold plaque touch the cornea during treatment. To enhance patient comfort and protect the cornea, an (0.1-mm-thick) amniotic membrane was interposed between the metal plaque edge and the cornea. Minimal ocular discomfort was noted during plaque radiation therapy. On a scale of 1 (none) to 10 (severe), all 6 patients reported pain levels of 1. As a tissue equivalent and because the mean thickness was only 0.1 mm, amniotic membranes had no significant effect on radiation dose calculations. No adverse effects, infections, or abrasions were noted. The amniotic membrane buffer technique improves patient comfort and protects the cornea during ophthalmic plaque radiation therapy.

New era of radiotherapy: an update in radiation-induced lung disease

PubMed Central

Benveniste, M. F. K.; Welsh, J.; Godoy, M. C. B.; Betancourt, S. L.; Mawlawi, O. R; Munden, R. F.

2014-01-01

Over the last few decades, advances in radiotherapy (RT) technology have improved delivery of radiation therapy dramatically. Advances in treatment planning with the development of image-guided radiotherapy and in techniques such as proton therapy, allows the radiation therapist to direct high doses of radiation to the tumour. These advancements result in improved local regional control while reducing potentially damaging dosage to surrounding normal tissues. It is important for radiologists to be aware of the radiological findings from these advances in order to differentiate expected radiation-induced lung injury (RILD) from recurrence, infection, and other lung diseases. In order to understand these changes and correlate them with imaging, the radiologist should have access to the radiation therapy treatment plans. PMID:23473474

Multiple Aperture Radiation Therapy (MART) for Breast Cancer

DTIC Science & Technology

2006-11-01

ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER Tianfang Li, Ph.D. 5e. TASK NUMBER Email: tfli@reyes.stanford.edu 5f. WORK UNIT...Radiation Therapy, XIVth International Conference on the Use of Computers in Radiation Therapy (ICCR), Soul , Korea, 2004. CONCLUSIONS Compared with...reconstruction artifacts due to in- sufficient angular sampling and dramatically degrades the image quality.24 Crucial issues in developing 4D CBCT are indeed how

[A Case of Central Diabetes Insipidus That Was Caused by Pituitary Metastasis of Lung Adenocarcinoma and Was Controlled by Radiation Therapy].

PubMed

Izumi, Yusuke; Masuda, Takeshi; Nabeshima, Shinji; Horimasu, Yasushi; Nakashima, Taku; Miyamoto, Shintaro; Iwamoto, Hiroshi; Fujitaka, Kazunori; Murakami, Yuji; Hamada, Hironobu; Nagata, Yasushi; Hattori, Noboru

2017-06-01

Pituitary metastasis of lung cancer is rare; however, it often causes diabetes insipidus. Although the majority of such patients are treated with radiation therapy, it remains unclear whether diabetes insipidus can be controlled by radiation therapy. A 72-year-old man was admitted to our hospital for hemosputum, headache, and polyuria. A chest CT scan showed a 3.0 cm mass in the left upper lobe of his lung. Bronchofiberscopy results confirmed the pathological diagnosis of lung adenocarcinoma. Based on the findings from PET-CT, head MRI, and endocrine tests, the diagnosis of lung adenocarcinoma( cT1bN0M1b, stage IV)accompanied with central diabetes insipidus caused by pituitary metastasis was made. Oral administration of desmopressin reduced urine volumes; however, chemotherapy for achieving stable disease in the primary tumor was ineffective in controlling the symptoms of diabetes insipidus. Chemotherapy was discontinued after 4 months because of severe hematological toxicity. During 2 months after the cessation of chemotherapy, polyuria worsened and, therefore, radiation therapy for pituitary metastasis was started. Following the radiation therapy, an apparent reduction in urine volume was observed. Our experience of this case suggests that radiation therapy for pituitary metastasis should be considered at the time when diabetes insipidus becomes clinically overt.

Task-based image quality assessment in radiation therapy: initial characterization and demonstration with CT simulation images

NASA Astrophysics Data System (ADS)

Dolly, Steven R.; Anastasio, Mark A.; Yu, Lifeng; Li, Hua

2017-03-01

In current radiation therapy practice, image quality is still assessed subjectively or by utilizing physically-based metrics. Recently, a methodology for objective task-based image quality (IQ) assessment in radiation therapy was proposed by Barrett et al.1 In this work, we present a comprehensive implementation and evaluation of this new IQ assessment methodology. A modular simulation framework was designed to perform an automated, computer-simulated end-to-end radiation therapy treatment. A fully simulated framework was created that utilizes new learning-based stochastic object models (SOM) to obtain known organ boundaries, generates a set of images directly from the numerical phantoms created with the SOM, and automates the image segmentation and treatment planning steps of a radiation therapy work ow. By use of this computational framework, therapeutic operating characteristic (TOC) curves can be computed and the area under the TOC curve (AUTOC) can be employed as a figure-of-merit to guide optimization of different components of the treatment planning process. The developed computational framework is employed to optimize X-ray CT pre-treatment imaging. We demonstrate that use of the radiation therapy-based-based IQ measures lead to different imaging parameters than obtained by use of physical-based measures.

Management of dental complications in a child with rhabdomyosarcoma.

PubMed

Jalali, Golnaz; Unkel, John H; Reed, James A

2012-01-01

Radiotherapy treatment options can cause adverse dental sequelae, including xerostomia, dental radiation caries, abnormal tooth development, and osteoradionecrosis (ORN). Hyperbaric oxygen (HBO) therapy can be used prophylactically or therapeutically to treat or reduce the risk of ORN. The purpose of this paper was to describe a case involving a 5-year-old male with rhabdomyosarcoma of the left temporal fossa and a history of radiation therapy who presented with gross radiation caries and xerostomia. Full-mouth extractions of all primary teeth were performed under general anesthesia, with the patient receiving HBO therapy before and after the surgery. The child was monitored postoperatively, and healing occurred with minimal post-operative complications. Based on his results, it can be concluded that hyperbaric oxygen therapy is an effective supplement to consider when treating children who have undergone radiation therapy and require dental care.

The physical basis and future of radiation therapy.

PubMed

Bortfeld, T; Jeraj, R

2011-06-01

The remarkable progress in radiation therapy over the last century has been largely due to our ability to more effectively focus and deliver radiation to the tumour target volume. Physics discoveries and technology inventions have been an important driving force behind this progress. However, there is still plenty of room left for future improvements through physics, for example image guidance and four-dimensional motion management and particle therapy, as well as increased efficiency of more compact and cheaper technologies. Bigger challenges lie ahead of physicists in radiation therapy beyond the dose localisation problem, for example in the areas of biological target definition, improved modelling for normal tissues and tumours, advanced multicriteria and robust optimisation, and continuous incorporation of advanced technologies such as molecular imaging. The success of physics in radiation therapy has been based on the continued "fuelling" of the field with new discoveries and inventions from physics research. A key to the success has been the application of the rigorous scientific method. In spite of the importance of physics research for radiation therapy, too few physicists are currently involved in cutting-edge research. The increased emphasis on more "professionalism" in medical physics will tip the situation even more off balance. To prevent this from happening, we argue that medical physics needs more research positions, and more and better academic programmes. Only with more emphasis on medical physics research will the future of radiation therapy and other physics-related medical specialties look as bright as the past, and medical physics will maintain a status as one of the most exciting fields of applied physics.

Prospective study to determine early hypertrophy of the contra-lateral liver lobe after unilobar, Yttrium-90, selective internal radiation therapy in patients with hepatocellular carcinoma.

PubMed

Teo, Jin Yao; Allen, John Carson; Ng, David Chee Eng; Abdul Latiff, Julianah Bee; Choo, Su Pin; Tai, David Wai-Meng; Low, Albert Su Chong; Cheah, Foong Koon; Chang, Jason Pik Eu; Kam, Juinn Huar; Lee, Victor T W; Chung, Alexander Yaw Fui; Chan, Chung Yip; Chow, Pierce Kah Hoe; Goh, Brian K P

2018-05-01

Liver resection is a major curative option in patients presenting with hepatocellular carcinoma. An inadequate functional liver remnant is a major limiting factor precluding liver resection. In recent years, hypertrophy of the functional liver remnant after selective internal radiation therapy hypertrophy has been observed, but the degree of hypertrophy in the early postselective internal radiation therapy period has not been well studied. We conducted a prospective study on patients undergoing unilobar, Yttrium-90 selective internal radiation therapy for hepatocellular carcinoma to evaluate early hypertrophy at 4-6 weeks and 8-12 weeks after selective internal radiation therapy. In the study, 24 eligible patients were recruited and had serial volumetric measurements performed. The median age was 66 years (38-75 years). All patients were either Child-Pugh Class A or B, and 6/24 patients had documented, clinically relevant portal hypertension; 15 of the 24 patients were hepatitis B positive. At 4-6 weeks, modest hypertrophy was seen (median 3%; range -12 to 42%) and this increased at 8-12 weeks (median 9%; range -12 to 179%). No preprocedural factors predictive of hypertrophy were identified. Hypertrophy of the functional liver remnant after selective internal radiation therapy with Yttrium-90 occurred in a subset of patients but was modest and unpredictable in the early stages. Selective internal radiation therapy cannot be recommended as a standard treatment modality to induce early hypertrophy for patients with hepatocellular carcinoma. (Surgery 2017;160:XXX-XXX.). Copyright © 2017 Elsevier Inc. All rights reserved.

The physical basis and future of radiation therapy

PubMed Central

Bortfeld, T; Jeraj, R

2011-01-01

The remarkable progress in radiation therapy over the last century has been largely due to our ability to more effectively focus and deliver radiation to the tumour target volume. Physics discoveries and technology inventions have been an important driving force behind this progress. However, there is still plenty of room left for future improvements through physics, for example image guidance and four-dimensional motion management and particle therapy, as well as increased efficiency of more compact and cheaper technologies. Bigger challenges lie ahead of physicists in radiation therapy beyond the dose localisation problem, for example in the areas of biological target definition, improved modelling for normal tissues and tumours, advanced multicriteria and robust optimisation, and continuous incorporation of advanced technologies such as molecular imaging. The success of physics in radiation therapy has been based on the continued “fuelling” of the field with new discoveries and inventions from physics research. A key to the success has been the application of the rigorous scientific method. In spite of the importance of physics research for radiation therapy, too few physicists are currently involved in cutting-edge research. The increased emphasis on more “professionalism” in medical physics will tip the situation even more off balance. To prevent this from happening, we argue that medical physics needs more research positions, and more and better academic programmes. Only with more emphasis on medical physics research will the future of radiation therapy and other physics-related medical specialties look as bright as the past, and medical physics will maintain a status as one of the most exciting fields of applied physics. PMID:21606068

WE-A-BRD-01: MR Imaging for Treatment Planning: What Every Physicist Should Know

DOE Office of Scientific and Technical Information (OSTI.GOV)

McGee, K.

2015-06-15

Ever since its introduction as a diagnostic imaging modality over 30 years ago, the radiation therapy community has acknowledged the utility of MR imaging as a tool for not only improved visualization of the target volume but also for demarcation of adjacent organs at risk. However, the adaptation of MR imaging in radiation oncology has, until recently been slow due in large part to the inability to image radiation therapy patients in their treatment position. With the introduction of so-called wide bore high field MR scanners, multi element flexible receive only RF coils, high performance imaging gradients and a rangemore » of volumetric imaging sequences it is now possible to obtain both high resolution and high signal-to-noise ratio images of in-treatment radiation therapy patients within clinically feasible imaging times. As a Result, there is renewed interest in the use of MR imaging for radiation oncology treatment planning that is being translated into physical siting and integration of these systems into radiation oncology departments. As MR imaging expands into the radiation oncology domain there is a significant and unmet need for radiation therapy physicists to become educated regarding the strengths, limitations and technical challenges associated with MR imaging. The purpose of this presentation is to address this need by providing an educational overview of the techniques and challenges associated with MR imaging of patients for radiation therapy treatment planning. As such this presentation will: 1) describe the fundamental differences between imaging of patients for diagnostic and therapeutic purposes (i.e. radiation therapy planning), 2) describe most commonly used imaging sequences and contrasts for identification of disease for radiation planning, 3) identify the most common sources of image distortion and techniques to reduce their effect on spatial fidelity of the MR data, 4) describe the effects of motion and methods to quantify/correct it, and 5) identify emergent techniques for performing MR only treatment simulation. Upon completion attendees will have a working understanding of the basic methodologies associated with MR imaging in radiation oncology, the unique technical challenges imposed by MR imaging in the treatment position and techniques to address these. Learning Objectives: 1. Understand the differences between MR imaging for diagnostic imaging and for radiation therapy planning. 2. Identify the most common sources of distortion and artifacts and simple methods to correct them. 3. Understand the challenges with MR imaging in the therapy treatment position and appropriate techniques to address them.« less

77 FR 68209 - Medicare and Medicaid Programs: Hospital Outpatient Prospective Payment and Ambulatory Surgical...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-11-15

...-through devices, brachytherapy sources, intraoperative radiation therapy (IORT), brachytherapy composite... Modulated Radiation Therapy I/OCE Integrated Outpatient Code Editor IOL Intraocular lens IOM Institute of Medicine IORT Intraoperative radiation treatment IPF Inpatient Psychiatric Facility IPPS [Hospital...

Monitoring tumor response of prostate cancer to radiation therapy by multi-parametric 1H and hyperpolarized 13C magnetic resonance imaging

NASA Astrophysics Data System (ADS)

Zhang, Vickie Yi

Radiation therapy is one of the most common curative therapies for patients with localized prostate cancer, but despite excellent success rates, a significant number of patients suffer post- treatment cancer recurrence. The accurate characterization of early tumor response remains a major challenge for the clinical management of these patients. Multi-parametric MRI/1H MR spectroscopy imaging (MRSI) has been shown to increase the diagnostic performance in evaluating the effectiveness of radiation therapy. 1H MRSI can detect altered metabolic profiles in cancerous tissue. In this project, the concentrations of prostate metabolites from snap-frozen biopsies of recurrent cancer after failed radiation therapy were correlated with histopathological findings to identify quantitative biomarkers that predict for residual aggressive versus indolent cancer. The total choline to creatine ratio was significantly higher in recurrent aggressive versus indolent cancer, suggesting that use of a higher threshold tCho/Cr ratio in future in vivo 1H MRSI studies could improve the selection and therapeutic planning for patients after failed radiation therapy. Varying radiation doses may cause a diverse effect on prostate cancer micro-environment and metabolism, which could hold the key to improving treatment protocols for individual patients. The recent development and clinical translation of hyperpolarized 13C MRI have provided the ability to monitor both changes in the tumor micro-environment and its metabolism using a multi-probe approach, [1-13C]pyruvate and 13C urea, combined with 1H Multi-parametric MRI. In this thesis, hyperpolarized 13C MRI, 1H dynamic contrast enhancement, and diffusion weighted imaging were used to identify early radiation dose response in a transgenic prostate cancer model. Hyperpolarized pyruvate to lactate metabolism significantly decreased in a dose dependent fashion by 1 day after radiation therapy, prior to any changes observed using 1H DCE and diffusion weighted imaging. Hyperpolarized 13C urea and 1H DCE both show increase in perfusion/permeability by 4 days post-radiation. In tumor region treated with high dose radiation, ADC values significantly increased post-radiation, suggesting a decrease in cellular density. These dose dependent changes can be used as markers of early tumor response to the impact of increasing doses of radiation therapy. In addition, a spectral-spatial pulse sequence was developed for the 14T to dynamically observe kinetic information in a transgenic prostate cancer model before and after radiation therapy. A novel modeling approach was proposed to parameterize perfusion in the kinetic modeling of pyruvate to lactate conversion for better characterization of pyruvate metabolism. Unlike single time point HP 13C urea imaging, quantitative pharmacokinetic parameters such as blood flow and extracellular extravascular volume fraction can be extracted from dynamic acquisitions. Blood flow measured by hyperpolarized 13C urea was highly correlated with Ktrans measured by 1H DCE, suggesting hyperpolarized urea might be able to provide similar information as 1H DCE. The results of this thesis show that Multi-parametric MRI, including functional MRI, 1H MRSI, and hyperpolarized 13C, holds great potential for evaluating early tumor response to radiation therapy of prostate cancer. The findings of this thesis will be useful in designing future studies for using combined Multi-parametric 1H and hyperpolarized 13C MRI to improve planning and assessing radiation therapy in individual prostate cancer patients.

Use of PET/CT instead of CT-only when planning for radiation therapy does not notably increase life years lost in children being treated for cancer.

PubMed

Kornerup, Josefine S; Brodin, Patrik; Birk Christensen, Charlotte; Björk-Eriksson, Thomas; Kiil-Berthelsen, Anne; Borgwardt, Lise; Munck Af Rosenschöld, Per

2015-04-01

PET/CT may be more helpful than CT alone for radiation therapy planning, but the added risk due to higher doses of ionizing radiation is unknown. To estimate the risk of cancer induction and mortality attributable to the [F-18]2-fluoro-2-deoxyglucose (FDG) PET and CT scans used for radiation therapy planning in children with cancer, and compare to the risks attributable to the cancer treatment. Organ doses and effective doses were estimated for 40 children (2-18 years old) who had been scanned using PET/CT as part of radiation therapy planning. The risk of inducing secondary cancer was estimated using the models in BEIR VII. The prognosis of an induced cancer was taken into account and the reduction in life expectancy, in terms of life years lost, was estimated for the diagnostics and compared to the life years lost attributable to the therapy. Multivariate linear regression was performed to find predictors for a high contribution to life years lost from the radiation therapy planning diagnostics. The mean contribution from PET to the effective dose from one PET/CT scan was 24% (range: 7-64%). The average proportion of life years lost attributable to the nuclear medicine dose component from one PET/CT scan was 15% (range: 3-41%). The ratio of life years lost from the radiation therapy planning PET/CT scans and that of the cancer treatment was on average 0.02 (range: 0.01-0.09). Female gender was associated with increased life years lost from the scans (P < 0.001). Using FDG-PET/CT instead of CT only when defining the target volumes for radiation therapy of children with cancer does not notably increase the number of life years lost attributable to diagnostic examinations.

Refusal of curative radiation therapy and surgery among patients with cancer.

PubMed

Aizer, Ayal A; Chen, Ming-Hui; Parekh, Arti; Choueiri, Toni K; Hoffman, Karen E; Kim, Simon P; Martin, Neil E; Hu, Jim C; Trinh, Quoc-Dien; Nguyen, Paul L

2014-07-15

Surgery and radiation therapy represent the only curative options for many patients with solid malignancies. However, despite the recommendations of their physicians, some patients refuse these therapies. This study characterized factors associated with refusal of surgical or radiation therapy as well as the impact of refusal of recommended therapy on patients with localized malignancies. We used the Surveillance, Epidemiology, and End Results program to identify a population-based sample of 925,127 patients who had diagnoses of 1 of 8 common malignancies for which surgery and/or radiation are believed to confer a survival benefit between 1995 and 2008. Refusal of oncologic therapy, as documented in the SEER database, was the primary outcome measure. Multivariable logistic regression was used to investigate factors associated with refusal. The impact of refusal of therapy on cancer-specific mortality was assessed with Fine and Gray's competing risks regression. In total, 2441 of 692,938 patients (0.4%) refused surgery, and 2113 of 232,189 patients (0.9%) refused radiation, despite the recommendations of their physicians. On multivariable analysis, advancing age, decreasing annual income, nonwhite race, and unmarried status were associated with refusal of surgery, whereas advancing age, decreasing annual income, Asian American race, and unmarried status were associated with refusal of radiation (P<.001 in all cases). Refusal of surgery and radiation were associated with increased estimates of cancer-specific mortality for all malignancies evaluated (hazard ratio [HR], 2.80, 95% confidence interval [CI], 2.59-3.03; P<.001 and HR 1.97 [95% CI, 1.78-2.18]; P<.001, respectively). Nonwhite, less affluent, and unmarried patients are more likely to refuse curative surgical and/or radiation-based oncologic therapy, raising concern that socioeconomic factors may drive some patients to forego potentially life-saving care. Copyright © 2014 Elsevier Inc. All rights reserved.

Refusal of Curative Radiation Therapy and Surgery Among Patients With Cancer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aizer, Ayal A., E-mail: aaaizer@partners.org; Chen, Ming-Hui; Parekh, Arti

Purpose: Surgery and radiation therapy represent the only curative options for many patients with solid malignancies. However, despite the recommendations of their physicians, some patients refuse these therapies. This study characterized factors associated with refusal of surgical or radiation therapy as well as the impact of refusal of recommended therapy on patients with localized malignancies. Methods and Materials: We used the Surveillance, Epidemiology, and End Results program to identify a population-based sample of 925,127 patients who had diagnoses of 1 of 8 common malignancies for which surgery and/or radiation are believed to confer a survival benefit between 1995 and 2008.more » Refusal of oncologic therapy, as documented in the SEER database, was the primary outcome measure. Multivariable logistic regression was used to investigate factors associated with refusal. The impact of refusal of therapy on cancer-specific mortality was assessed with Fine and Gray's competing risks regression. Results: In total, 2441 of 692,938 patients (0.4%) refused surgery, and 2113 of 232,189 patients (0.9%) refused radiation, despite the recommendations of their physicians. On multivariable analysis, advancing age, decreasing annual income, nonwhite race, and unmarried status were associated with refusal of surgery, whereas advancing age, decreasing annual income, Asian American race, and unmarried status were associated with refusal of radiation (P<.001 in all cases). Refusal of surgery and radiation were associated with increased estimates of cancer-specific mortality for all malignancies evaluated (hazard ratio [HR], 2.80, 95% confidence interval [CI], 2.59-3.03; P<.001 and HR 1.97 [95% CI, 1.78-2.18]; P<.001, respectively). Conclusions: Nonwhite, less affluent, and unmarried patients are more likely to refuse curative surgical and/or radiation-based oncologic therapy, raising concern that socioeconomic factors may drive some patients to forego potentially life-saving care.« less

The Clinical Development of Molecularly Targeted Agents in Combination With Radiation Therapy: A Pharmaceutical Perspective

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ataman, Ozlem U., E-mail: ouataman@hotmail.com; Sambrook, Sally J.; Wilks, Chris

2012-11-15

Summary: This paper explores historical and current roles of pharmaceutical industry sponsorship of clinical trials testing radiation therapy combinations with molecularly targeted agents and attempts to identify potential solutions to expediting further combination studies. An analysis of clinical trials involving a combination of radiation therapy and novel cancer therapies was performed. Ongoing and completed trials were identified by searching the (clinicaltrials.gov) Web site, in the first instance, with published trials of drugs of interest identified through American Society of Clinical Oncology, European CanCer Organisation/European Society for Medical Oncology, American Society for Radiation Oncology/European Society for Therapeutic Radiology and Oncology, andmore » PubMed databases and then cross-correlated with (clinicaltrials.gov) protocols. We examined combination trials involving radiation therapy with novel agents and determined their distribution by tumor type, predominant molecular mechanisms examined in combination to date, timing of initiation of trials relative to a novel agent's primary development, and source of sponsorship of such trials. A total of 564 studies of targeted agents in combination with radiation therapy were identified with or without concomitant chemotherapy. Most studies were in phase I/II development, with only 36 trials in phase III. The tumor site most frequently studied was head and neck (26%), followed by non-small cell lung cancer. Pharmaceutical companies were the sponsors of 33% of studies overall and provided support for only 16% of phase III studies. In terms of pharmaceutical sponsorship, Genentech was the most active sponsor of radiation therapy combinations (22%), followed by AstraZeneca (14%). Most radiation therapy combination trials do not appear to be initiated until after drug approval. In phase III studies, the most common (58%) primary endpoint was overall survival. Collectively, this analysis suggests that such trials are not given priority by pharmaceutical companies. The potential reasons for this and some challenges and possible solutions are discussed.« less

WE-F-209-02: Radiation Safety Surveys of Linear Accelerators

DOE Office of Scientific and Technical Information (OSTI.GOV)

Martin, M.

2016-06-15

Over the past few years, numerous Accreditation Bodies, Regulatory Agencies, and State Regulations have implemented requirements for Radiation Safety Surveys following installation or modification to x-ray rooms. The objective of this session is to review best practices in performing radiation safety surveys for both Therapy and Diagnostic installations, as well as a review of appropriate survey instruments. This session will be appropriate for both therapy and imaging physicists who are looking to increase their working knowledge of radiation safety surveys. Learning Objectives: Identify Appropriate Survey Meters for Radiation Safety Surveys Develop best practices for Radiation Safety Surveys for Therapy unitsmore » that include common areas of concern. Develop best practices for Radiation Safety Surveys of Diagnostic and Nuclear Medicine rooms. Identify acceptable dose levels and the factors that affect the calculations associated with performing Radiation Safety Surveys.« less

Chronic radiation-induced dermatitis: challenges and solutions.

PubMed

Spałek, Mateusz

2016-01-01

Chronic radiation dermatitis is a late side effect of skin irradiation, which may deteriorate patients' quality of life. There is a lack of precise data about its incidence; however, several risk factors may predispose to the development of this condition. It includes radiotherapy dose, fractionation, technique, concurrent systemic therapy, comorbidities, and personal and genetic factors. Chronic radiation dermatitis is mostly caused by the imbalance of proinflammatory and profibrotic cytokines. Clinical manifestation includes changes in skin appearance, wounds, ulcerations, necrosis, fibrosis, and secondary cancers. The most severe complication of irradiation is extensive radiation-induced fibrosis (RIF). RIF can manifest in many ways, such as skin induration and retraction, lymphedema or restriction of joint motion. Diagnosis of chronic radiation dermatitis is usually made by clinical examination. In case of unclear clinical manifestation, a biopsy and histopathological examination are recommended to exclude secondary malignancy. The most effective prophylaxis of chronic radiation dermatitis is the use of proper radiation therapy techniques to avoid unnecessary irradiation of healthy skin. Treatment of chronic radiation dermatitis is demanding. The majority of the interventions are based only on clinical practice. Telangiectasia may be treated with pulse dye laser therapy. Chronic postirradiation wounds need special dressings. In case of necrosis or severe ulceration, surgical intervention may be considered. Management of RIF should be complex. Available methods are rehabilitative care, pharmacotherapy, hyperbaric oxygen therapy, and laser therapy. Future challenges include the assessment of late skin toxicity in modern irradiation techniques. Special attention should be paid on genomics and radiomics that allow scientists and clinicians to select patients who are at risk of the development of chronic radiation dermatitis. Novel treatment methods and clinical trials are strongly needed to provide more efficacious therapies.

Quantifying public radiation exposure related to lutetium-177 octreotate therapy for the development of a safe outpatient treatment protocol.

PubMed

Olmstead, Craig; Cruz, Kyle; Stodilka, Robert; Zabel, Pamela; Wolfson, Robert

2015-02-01

Radionuclide therapies, including treatment of neuroendocrine tumors with lutetium-177 (Lu-177) octreotate, often involve hospital admission to minimize radiation exposure to the public. Overnight admission due to Lu-177 octreotate therapy incurs additional cost for the hospital and is an inconvenience for the patient. This study endeavors to characterize the potential radiation risk to caregivers and the public should Lu-177 octreotate therapies be performed on an outpatient basis. Dose rate measurements of radiation emanating from 10 patients were taken 30 min, 4, and 20 h after initiation of Lu-177 octreotate therapy. Instadose radiation dose measurement monitors were also placed around the patients' rooms to assess the potential cumulative radiation exposure during the initial 30 min-4 h after treatment (simulating the hospital-based component of the outpatient model) as well as 4-20 h after treatment (simulating the discharged outpatient portion). The mean recorded dose rate at 30 min, 4, and 20 h after therapy was 20.4, 14.0, and 6.6 μSv/h, respectively. The majority of the cumulative dose readings were below the minimum recordable threshold of 0.03 mSv, with a maximum dose recorded of 0.18 mSv. Given the low dose rate and cumulative levels of radiation measured, the results support that an outpatient Lu-177 octreotate treatment protocol would not jeopardize public safety. Nevertheless, the concept of ALARA still requires that detailed radiation safety protocols be developed for Lu-177 octreotate outpatients to minimize radiation exposure to family members, caregivers, and the general public.

Curcumin Modulates the Radiosensitivity of Colorectal Cancer Cells by Suppressing Constitutive and Inducible NF-{kappa}B Activity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sandur, Santosh K.; Deorukhkar, Amit; Pandey, Manoj K.

2009-10-01

Purpose: Radiation therapy is an integral part of the preoperative treatment of rectal cancers. However, only a minority of patients achieve a complete pathologic response to therapy because of resistance of these tumors to radiation therapy. This resistance may be mediated by constitutively active pro-survival signaling pathways or by inducible/acquired mechanisms in response to radiation therapy. Simultaneous inhibition of these pathways can sensitize these tumors to radiation therapy. Methods and Materials: Human colorectal cancer cells were exposed to clinically relevant doses of gamma rays, and the mechanism of their radioresistance was investigated. We characterized the transcription factor nuclear factor-{kappa}B (NF-{kappa}B)more » activation as a mechanism of inducible radioresistance in colorectal cancer and used curcumin, the active ingredient in the yellow spice turmeric, to overcome this resistance. Results: Curcumin inhibited the proliferation and the post-irradiation clonogenic survival of multiple colorectal cancer cell lines. Radiation stimulated NF-{kappa}B activity in a dose- and time-dependent manner, whereas curcumin suppressed this radiation-induced NF-{kappa}B activation via inhibition of radiation-induced phosphorylation and degradation of inhibitor of {kappa}B alpha, inhibition of inhibitor of {kappa}B kinase activity, and inhibition of Akt phosphorylation. Curcumin also suppressed NF-{kappa}B-regulated gene products (Bcl-2, Bcl-x{sub L}, inhibitor of apoptosis protein-2, cyclooxygenase-2, and cyclin D1). Conclusions: Our results suggest that transient inducible NF-{kappa}B activation provides a prosurvival response to radiation that may account for development of radioresistance. Curcumin blocks this signaling pathway and potentiates the antitumor effects of radiation therapy.« less

Modern Radiation Therapy for Hodgkin Lymphoma: Field and Dose Guidelines From the International Lymphoma Radiation Oncology Group (ILROG)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Specht, Lena, E-mail: lena.specht@regionh.dk; Yahalom, Joachim; Illidge, Tim

2014-07-15

Radiation therapy (RT) is the most effective single modality for local control of Hodgkin lymphoma (HL) and an important component of therapy for many patients. These guidelines have been developed to address the use of RT in HL in the modern era of combined modality treatment. The role of reduced volumes and doses is addressed, integrating modern imaging with 3-dimensional (3D) planning and advanced techniques of treatment delivery. The previously applied extended field (EF) and original involved field (IF) techniques, which treated larger volumes based on nodal stations, have now been replaced by the use of limited volumes, based solelymore » on detectable nodal (and extranodal extension) involvement at presentation, using contrast-enhanced computed tomography, positron emission tomography/computed tomography, magnetic resonance imaging, or a combination of these techniques. The International Commission on Radiation Units and Measurements concepts of gross tumor volume, clinical target volume, internal target volume, and planning target volume are used for defining the targeted volumes. Newer treatment techniques, including intensity modulated radiation therapy, breath-hold, image guided radiation therapy, and 4-dimensional imaging, should be implemented when their use is expected to decrease significantly the risk for normal tissue damage while still achieving the primary goal of local tumor control. The highly conformal involved node radiation therapy (INRT), recently introduced for patients for whom optimal imaging is available, is explained. A new concept, involved site radiation therapy (ISRT), is introduced as the standard conformal therapy for the scenario, commonly encountered, wherein optimal imaging is not available. There is increasing evidence that RT doses used in the past are higher than necessary for disease control in this era of combined modality therapy. The use of INRT and of lower doses in early-stage HL is supported by available data. Although the use of ISRT has not yet been validated in a formal study, it is more conservative than INRT, accounting for suboptimal information and appropriately designed for safe local disease control. The goal of modern smaller field radiation therapy is to reduce both treatment volume and treatment dose while maintaining efficacy and minimizing acute and late sequelae. This review is a consensus of the International Lymphoma Radiation Oncology Group (ILROG) Steering Committee regarding the modern approach to RT in the treatment of HL, outlining a new concept of ISRT in which reduced treatment volumes are planned for the effective control of involved sites of HL. Nodal and extranodal non-Hodgkin lymphomas (NHL) are covered separately by ILROG guidelines.« less

Modern radiation therapy for Hodgkin lymphoma: field and dose guidelines from the international lymphoma radiation oncology group (ILROG).

PubMed

Specht, Lena; Yahalom, Joachim; Illidge, Tim; Berthelsen, Anne Kiil; Constine, Louis S; Eich, Hans Theodor; Girinsky, Theodore; Hoppe, Richard T; Mauch, Peter; Mikhaeel, N George; Ng, Andrea

2014-07-15

Radiation therapy (RT) is the most effective single modality for local control of Hodgkin lymphoma (HL) and an important component of therapy for many patients. These guidelines have been developed to address the use of RT in HL in the modern era of combined modality treatment. The role of reduced volumes and doses is addressed, integrating modern imaging with 3-dimensional (3D) planning and advanced techniques of treatment delivery. The previously applied extended field (EF) and original involved field (IF) techniques, which treated larger volumes based on nodal stations, have now been replaced by the use of limited volumes, based solely on detectable nodal (and extranodal extension) involvement at presentation, using contrast-enhanced computed tomography, positron emission tomography/computed tomography, magnetic resonance imaging, or a combination of these techniques. The International Commission on Radiation Units and Measurements concepts of gross tumor volume, clinical target volume, internal target volume, and planning target volume are used for defining the targeted volumes. Newer treatment techniques, including intensity modulated radiation therapy, breath-hold, image guided radiation therapy, and 4-dimensional imaging, should be implemented when their use is expected to decrease significantly the risk for normal tissue damage while still achieving the primary goal of local tumor control. The highly conformal involved node radiation therapy (INRT), recently introduced for patients for whom optimal imaging is available, is explained. A new concept, involved site radiation therapy (ISRT), is introduced as the standard conformal therapy for the scenario, commonly encountered, wherein optimal imaging is not available. There is increasing evidence that RT doses used in the past are higher than necessary for disease control in this era of combined modality therapy. The use of INRT and of lower doses in early-stage HL is supported by available data. Although the use of ISRT has not yet been validated in a formal study, it is more conservative than INRT, accounting for suboptimal information and appropriately designed for safe local disease control. The goal of modern smaller field radiation therapy is to reduce both treatment volume and treatment dose while maintaining efficacy and minimizing acute and late sequelae. This review is a consensus of the International Lymphoma Radiation Oncology Group (ILROG) Steering Committee regarding the modern approach to RT in the treatment of HL, outlining a new concept of ISRT in which reduced treatment volumes are planned for the effective control of involved sites of HL. Nodal and extranodal non-Hodgkin lymphomas (NHL) are covered separately by ILROG guidelines. Copyright © 2014 Elsevier Inc. All rights reserved.

Optimizing Timing of Immunotherapy Improves Control of Tumors by Hypofractionated Radiation Therapy

PubMed Central

Baird, Jason R.; Savage, Talicia; Cottam, Benjamin; Friedman, David; Bambina, Shelly; Messenheimer, David J.; Fox, Bernard; Newell, Pippa; Bahjat, Keith S.; Gough, Michael J.; Crittenden, Marka R.

2016-01-01

The anecdotal reports of promising results seen with immunotherapy and radiation in advanced malignancies have prompted several trials combining immunotherapy and radiation. However, the ideal timing of immunotherapy with radiation has not been clarified. Tumor bearing mice were treated with 20Gy radiation delivered only to the tumor combined with either anti-CTLA4 antibody or anti-OX40 agonist antibody. Immunotherapy was delivered at a single timepoint around radiation. Surprisingly, the optimal timing of these therapies varied. Anti-CTLA4 was most effective when given prior to radiation therapy, in part due to regulatory T cell depletion. Administration of anti-OX40 agonist antibody was optimal when delivered one day following radiation during the post-radiation window of increased antigen presentation. Combination treatment of anti-CTLA4, radiation, and anti-OX40 using the ideal timing in a transplanted spontaneous mammary tumor model demonstrated tumor cures. These data demonstrate that the combination of immunotherapy and radiation results in improved therapeutic efficacy, and that the ideal timing of administration with radiation is dependent on the mechanism of action of the immunotherapy utilized. PMID:27281029

Endoscopic treatment of chronic radiation proctopathy.

PubMed

Wilson, Sydney A; Rex, Douglas K

2006-09-01

Chronic radiation proctopathy is a complication of pelvic radiation therapy. The acute phase of radiation injury to the rectum occurs during or up to 3 months following radiation. Acute radiation injury can continue into a chronic phase or chronic radiation proctopathy may develop after a latent period of several months or years. Symptoms associated with the condition include diarrhea, rectal pain, bleeding, tenesmus, and stricture formation. Of the various symptoms, only bleeding from radiation-induced telangiectasias is amenable to endoscopic therapy. This paper summarizes the findings of experts in the field on endoscopic treatment of bleeding from chronic radiation proctopathy. Medical management is generally ineffective in controlling bleeding from chronic radiation proctopathy. Surgical intervention has a high incidence of morbidity. Promising advances have been made in endoscopic therapy, including formalin, neodymium/yttrium aluminum garnet, argon and potassium titanyl phosphate laser treatments, as well as argon plasma coagulation. Argon plasma coagulation presents an effective, efficient, inexpensive and reasonably safe noncontact method for destruction of radiation telangiectasias. Based on currently available data and trends, argon plasma coagulation is the favored treatment for bleeding from chronic radiation proctopathy.

Hyperbaric Oxygen Therapy in Treating Long-Term Gastrointestinal Adverse Effects Caused by Radiation Therapy in Patients With Pelvic Cancer

ClinicalTrials.gov

2011-07-14

Bladder Cancer; Cervical Cancer; Colorectal Cancer; Endometrial Cancer; Gastrointestinal Complications; Long-term Effects Secondary to Cancer Therapy in Adults; Ovarian Cancer; Prostate Cancer; Radiation Toxicity; Sarcoma; Testicular Germ Cell Tumor; Vaginal Cancer

Radiation-Induced Second Cancer Risk Estimates From Radionuclide Therapy

NASA Astrophysics Data System (ADS)

Bednarz, Bryan; Besemer, Abigail

2017-09-01

The use of radionuclide therapy in the clinical setting is expected to increase significantly over the next decade. There is an important need to understand the radiation-induced second cancer risk associated with these procedures. In this study the radiation-induced cancer risk in five radionuclide therapy patients was investigated. These patients underwent serial SPECT imaging scans following injection as part of a clinical trial testing the efficacy of a 131Iodine-labeled radiopharmaceutical. Using these datasets the committed absorbed doses to multiple sensitive structures were calculated using RAPID, which is a novel Monte Carlo-based 3D dosimetry platform developed for personalized dosimetry. The excess relative risk (ERR) for radiation-induced cancer in these structures was then derived from these dose estimates following the recommendations set forth in the BEIR VII report. The radiation-induced leukemia ERR was highest among all sites considered reaching a maximum value of approximately 4.5. The radiation-induced cancer risk in the kidneys, liver and spleen ranged between 0.3 and 1.3. The lifetime attributable risks (LARs) were also calculated, which ranged from 30 to 1700 cancers per 100,000 persons and were highest for leukemia and the liver for both males and females followed by radiation-induced spleen and kidney cancer. The risks associated with radionuclide therapy are similar to the risk associated with external beam radiation therapy.

Accelerators for Cancer Therapy

DOE R&D Accomplishments Database

Lennox, Arlene J.

2000-05-30

The vast majority of radiation treatments for cancerous tumors are given using electron linacs that provide both electrons and photons at several energies. Design and construction of these linacs are based on mature technology that is rapidly becoming more and more standardized and sophisticated. The use of hadrons such as neutrons, protons, alphas, or carbon, oxygen and neon ions is relatively new. Accelerators for hadron therapy are far from standardized, but the use of hadron therapy as an alternative to conventional radiation has led to significant improvements and refinements in conventional treatment techniques. This paper presents the rationale for radiation therapy, describes the accelerators used in conventional and hadron therapy, and outlines the issues that must still be resolved in the emerging field of hadron therapy.

Palliative radiation therapy for bone metastases: Update of an ASTRO Evidence-Based Guideline.

PubMed

Lutz, Stephen; Balboni, Tracy; Jones, Joshua; Lo, Simon; Petit, Joshua; Rich, Shayna E; Wong, Rebecca; Hahn, Carol

The purpose is to provide an update the Bone Metastases Guideline published in 2011 based on evidence complemented by expert opinion. The update will discuss new high-quality literature for the 8 key questions from the original guideline and implications for practice. A systematic PubMed search from the last date included in the original Guideline yielded 414 relevant articles. Ultimately, 20 randomized controlled trials, 32 prospective nonrandomized studies, and 4 meta-analyses/pooled analyses were selected and abstracted into evidence tables. The authors synthesized the evidence and reached consensus on the included recommendations. Available literature continues to support pain relief equivalency between single and multiple fraction regimens for bone metastases. High-quality data confirm single fraction radiation therapy may be delivered to spine lesions with acceptable late toxicity. One prospective, randomized trial confirms both peripheral and spine-based painful metastases can be successfully and safely palliated with retreatment for recurrence pain with adherence to published dosing constraints. Advanced radiation therapy techniques such as stereotactic body radiation therapy lack high-quality data, leading the panel to favor its use on a clinical trial or when results will be collected in a registry. The panel's conclusion remains that surgery, radionuclides, bisphosphonates, and kyphoplasty/vertebroplasty do not obviate the need for external beam radiation therapy. Updated data analysis confirms that radiation therapy provides excellent palliation for painful bone metastases and that retreatment is safe and effective. Although adherence to evidence-based medicine is critical, thorough expert radiation oncology physician judgment and discretion regarding number of fractions and advanced techniques are also essential to optimize outcomes when considering the patient's overall health, life expectancy, comorbidities, tumor biology, anatomy, previous treatment including prior radiation at or near current site of treatment, tumor and normal tissue response history to local and systemic therapies, and other factors related to the patient, tumor characteristics, or treatment. Copyright © 2016 American Society for Radiation Oncology. Published by Elsevier Inc. All rights reserved.

Initial clinical outcomes of audiovisual-assisted therapeutic ambience in radiation therapy (AVATAR).

PubMed

Hiniker, Susan M; Bush, Karl; Fowler, Tyler; White, Evan C; Rodriguez, Samuel; Maxim, Peter G; Donaldson, Sarah S; Loo, Billy W

Radiation therapy is an important component of treatment for many childhood cancers. Depending upon the age and maturity of the child, pediatric radiation therapy often requires general anesthesia for immobilization, position reproducibility, and daily treatment delivery. We designed and clinically implemented a radiation therapy-compatible audiovisual system that allows children to watch streaming video during treatment, with the goal of reducing the need for daily anesthesia through immersion in video. We designed an audiovisual-assisted therapeutic ambience in radiation therapy (AVATAR) system using a digital media player with wireless streaming and pico projector, and a radiolucent display screen positioned within the child's field of view to him or her with sufficient entertainment and distraction for the duration of serial treatments without the need for daily anesthesia. We piloted this system in 25 pediatric patients between the ages of 3 and 12 years. We calculated the number of fractions of radiation for which this system was used successfully and anesthesia avoided and compared it with the anesthesia rates reported in the literature for children of this age. Twenty-three of 25 patients (92%) were able to complete the prescribed course of radiation therapy without anesthesia using the AVATAR system, with a total of 441 fractions of treatment administered when using AVATAR. The median age of patients successfully treated with this approach was 6 years. Seven of the 23 patients were initially treated with daily anesthesia and were successfully transitioned to use of the AVATAR system. Patients and families reported an improved treatment experience with the use of the AVATAR system compared with anesthesia. The AVATAR system enables a high proportion of children to undergo radiation therapy without anesthesia compared with reported anesthesia rates, justifying continued development and clinical investigation of this technique. Copyright © 2016 American Society for Radiation Oncology. Published by Elsevier Inc. All rights reserved.

The effect of laughter therapy on radiation dermatitis in patients with breast cancer: a single-blind prospective pilot study

PubMed Central

Kong, Moonkyoo; Shin, Sung Hee; Lee, Eunmi; Yun, Eun Kyoung

2014-01-01

Background There have not yet been any published studies on the effects of laughter therapy on radiation-induced dermatitis in breast cancer patients treated with radiotherapy (RT). We assessed the effectiveness of laughter therapy in preventing radiation dermatitis in patients with breast cancer. Methods Thirty-seven patients were prospectively enrolled in this study. Eighteen patients were assigned to the experimental group and the other 19 patients were assigned to the control group. The patients who were assigned to the experimental group received laughter therapy during RT. Laughter therapy was started at the onset of RT and was provided twice a week until completion of RT. The patients who were assigned to the control group only received RT without laughter therapy. The grade of radiation dermatitis was scored by a radiation oncologist who was blinded to subject assignment. The patients’ evaluation of pain within the RT field was also assessed. Results In the experimental group, radiation dermatitis of grade 3, 2, and 1 developed in five (33.3%), five (33.3%), and five patients (33.3%), respectively. In comparison, in the control group, radiation dermatitis of grade 3, 2, 1, and 0 developed in seven (36.8%), nine (47.4%), two (10.5%), and one patient (5.3%), respectively. The experimental group exhibited a lower incidence of grade 2 or worse radiation dermatitis than the control group (33.3% versus 47.4%). The mean maximal pain scores in the experimental and control group were 2.53 and 3.95, respectively. The experimental group complained of less severe pain than the control group during RT. However, these differences were not statistically significant. Conclusion The results of this study show that laughter therapy can have a beneficial role in preventing radiation dermatitis in patients with breast cancer. To confirm the results of our study, well-designed randomized studies with large sample sizes are required. PMID:25395864

Radiation with or without Antiandrogen Therapy in Recurrent Prostate Cancer

PubMed Central

Shipley, W.U.; Seiferheld, W.; Lukka, H.R.; Major, P.P.; Heney, N.M.; Grignon, D.J.; Sartor, O.; Patel, M.P.; Bahary, J.-P.; Zietman, A.L.; Pisansky, T.M.; Zeitzer, K.L.; Lawton, C.A.F.; Feng, F.Y.; Lovett, R.D.; Balogh, A.G.; Souhami, L.; Rosenthal, S.A.; Kerlin, K.J.; Dignam, J.J.; Pugh, S.L.; Sandler, H.M.

2017-01-01

BACKGROUND Salvage radiation therapy is often necessary in men who have undergone radical pros-tatectomy and have evidence of prostate-cancer recurrence signaled by a persistently or recurrently elevated prostate-specific antigen (PSA) level. Whether antiandrogen therapy with radiation therapy will further improve cancer control and prolong overall survival is unknown. METHODS In a double-blind, placebo-controlled trial conducted from 1998 through 2003, we assigned 760 eligible patients who had undergone prostatectomy with a lymphadenectomy and had disease, as assessed on pathological testing, with a tumor stage of T2 (confined to the prostate but with a positive surgical margin) or T3 (with histologic extension beyond the prostatic capsule), no nodal involvement, and a detectable PSA level of 0.2 to 4.0 ng per milliliter to undergo radiation therapy and receive either antiandrogen therapy (24 months of bicalutamide at a dose of 150 mg daily) or daily placebo tablets during and after radiation therapy. The primary end point was the rate of overall survival. RESULTS The median follow-up among the surviving patients was 13 years. The actuarial rate of overall survival at 12 years was 76.3% in the bicalutamide group, as compared with 71.3% in the placebo group (hazard ratio for death, 0.77; 95% confidence interval, 0.59 to 0.99; P=0.04). The 12-year incidence of death from prostate cancer, as assessed by means of central review, was 5.8% in the bicalutamide group, as compared with 13.4% in the placebo group (P<0.001). The cumulative incidence of metastatic prostate cancer at 12 years was 14.5% in the bicalutamide group, as compared with 23.0% in the placebo group (P=0.005). The incidence of late adverse events associated with radiation therapy was similar in the two groups. Gynecomastia was recorded in 69.7% of the patients in the bicalutamide group, as compared with 10.9% of those in the placebo group (P<0.001). CONCLUSIONS The addition of 24 months of antiandrogen therapy with daily bicalutamide to salvage radiation therapy resulted in significantly higher rates of long-term overall survival and lower incidences of metastatic prostate cancer and death from prostate cancer than radiation therapy plus placebo. (Funded by the National Cancer Institute and AstraZeneca; RTOG 9601 ClinicalTrials.gov number, NCT00002874.) PMID:28146658

Proton therapy versus intensity modulated x-ray therapy in the treatment of prostate cancer: Estimating secondary cancer risks

NASA Astrophysics Data System (ADS)

Fontenot, Jonas David

External beam radiation therapy is used to treat nearly half of the more than 200,000 new cases of prostate cancer diagnosed in the United States each year. During a radiation therapy treatment, healthy tissues in the path of the therapeutic beam are exposed to high doses. In addition, the whole body is exposed to a low-dose bath of unwanted scatter radiation from the pelvis and leakage radiation from the treatment unit. As a result, survivors of radiation therapy for prostate cancer face an elevated risk of developing a radiogenic second cancer. Recently, proton therapy has been shown to reduce the dose delivered by the therapeutic beam to normal tissues during treatment compared to intensity modulated x-ray therapy (IMXT, the current standard of care). However, the magnitude of stray radiation doses from proton therapy, and their impact on this incidence of radiogenic second cancers, was not known. The risk of a radiogenic second cancer following proton therapy for prostate cancer relative to IMXT was determined for 3 patients of large, median, and small anatomical stature. Doses delivered to healthy tissues from the therapeutic beam were obtained from treatment planning system calculations. Stray doses from IMXT were taken from the literature, while stray doses from proton therapy were simulated using a Monte Carlo model of a passive scattering treatment unit and an anthropomorphic phantom. Baseline risk models were taken from the Biological Effects of Ionizing Radiation VII report. A sensitivity analysis was conducted to characterize the uncertainty of risk calculations to uncertainties in the risk model, the relative biological effectiveness (RBE) of neutrons for carcinogenesis, and inter-patient anatomical variations. The risk projections revealed that proton therapy carries a lower risk for radiogenic second cancer incidence following prostate irradiation compared to IMXT. The sensitivity analysis revealed that the results of the risk analysis depended only weakly on uncertainties in the risk model and inter-patient variations. Second cancer risks were sensitive to changes in the RBE of neutrons. However, the findings of the study were qualitatively consistent for all patient sizes and risk models considered, and for all neutron RBE values less than 100.

Application and possible mechanisms of combining LLLT (low level laser therapy), infrared hyperthermia and ionizing radiation in the treatment of cancer

NASA Astrophysics Data System (ADS)

Abraham, Edward H.; Woo, Van H.; Harlin-Jones, Cheryl; Heselich, Anja; Frohns, Florian

2014-02-01

Benefit of concomitant infrared hyperthermia and low level laser therapy and ionizing radiation is evaluated in this study. The purpose/objectives: presentation with locally advanced bulky superficial tumors is clinically challenging. To enhance the efficacy of chemotherapy and IMRT (intensity-modulated radiation therapy) and/or electron beam therapy we have developed an inexpensive and clinically effective infrared hyperthermia approach that combines black-body infrared radiation with halogen spectrum radiation and discrete wave length infrared clinical lasers LLLT. The goal is to produce a composite spectrum extending from the far infrared to near infrared and portions of the visible spectrum with discrete penetrating wavelengths generated by the clinical infrared lasers with frequencies of 810 nm and/or 830 nm. The composite spectrum from these sources is applied before and after radiation therapy. We monitor the surface and in some cases deeper temperatures with thermal probes, but use an array of surface probes as the limiting safe thermal constraint in patient treatment while at the same time maximizing infrared entry to deeper tissue layers. Fever-grade infrared hyperthermia is produced in the first centimeters while non-thermal infrared effects act at deeper tissue layers. The combination of these effects with ionizing radiation leads to improved tumor control in many cancers.

Cranial Radiation Therapy and Damage to Hippocampal Neurogenesis

ERIC Educational Resources Information Center

Monje, Michelle

2008-01-01

Cranial radiation therapy is associated with a progressive decline in cognitive function, prominently memory function. Impairment of hippocampal neurogenesis is thought to be an important mechanism underlying this cognitive decline. Recent work has elucidated the mechanisms of radiation-induced failure of neurogenesis. Potential therapeutic…

Medical Applications of Synchrotron Radiation

NASA Astrophysics Data System (ADS)

Prezado, Yolanda; Martínez-Rovira, Immaculada

This chapter describes the state-of-art of synchrotron radiation therapies in the treatment of radioresistant tumors. The tolerance of the surrounding healthy tissue severely limits the achievement of a curative treatment for some brain tumors, like gliomas. This restriction is especially important in children, due to the high risk of complications in the development of the central nervous system. In addition, the treatment of tumors close to an organ at risk, like the spinal cord, is also restrained. One possible solution is the development of new radiotherapy techniques would exploit radically different irradiation modes, as it is the case of synchrotron radiotherapies. Their distinct features allow to modify the biological equivalent doses. In this chapter the three new approaches under development at the European Synchrotron Radiation Facility (ESRF), in Grenoble (France), will be described, namely: stereotactic synchrotron radiation therapy, microbeam radiation therapy and minibeam radiation therapy. The promising results obtained in the treatment of high grade brain tumors in preclinical studies have paved the way to the forthcoming clinical trials, currently in preparation.

Constrictive Pericarditis 5 Months after Radiation Therapy in a 62-Year-Old Woman with Esophageal Cancer.

PubMed

Yeneneh, Beeletsega T; Allen, Sorcha; Panse, Prasad; Mookadam, Farouk; Rule, William

2017-12-01

Most pericardial changes appear within a few weeks in patients who have undergone radiation therapy for thoracic neoplasms. Chronic pericardial constriction typically occurs decades later, consequent to fibrosis. Early constrictive pericarditis after chest irradiation is quite rare. We report the case of a 62-year-old woman who underwent radiation therapy for esophageal cancer and presented with constrictive pericarditis 5 months later. We searched the English-language medical literature from January 1986 through December 2015 for reports of early constrictive pericarditis after irradiation for thoracic malignancies. We defined "early" as a diagnosis within one year after radiation therapy. Five cases fit our criteria, and we summarize the findings here. To our knowledge, ours is the first definitive report of a patient with esophageal cancer to present with early radiation-induced constrictive pericarditis. We conclude that constrictive pericarditis can occur early after radiation for thoracic malignancies, albeit rarely. When planning care for cancer patients, awareness of this sequela is helpful.

Decision regret in men undergoing dose-escalated radiation therapy for prostate cancer.

PubMed

Steer, Anna N; Aherne, Noel J; Gorzynska, Karen; Hoffman, Matthew; Last, Andrew; Hill, Jacques; Shakespeare, Thomas P

2013-07-15

Decision regret (DR) is a negative emotion associated with medical treatment decisions, and it is an important patient-centered outcome after therapy for localized prostate cancer. DR has been found to occur in up to 53% of patients treated for localized prostate cancer, and it may vary depending on treatment modality. DR after modern dose-escalated radiation therapy (DE-RT) has not been investigated previously, to our knowledge. Our primary aim was to evaluate DR in a cohort of patients treated with DE-RT. We surveyed 257 consecutive patients with localized prostate cancer who had previously received DE-RT, by means of a validated questionnaire. There were 220 responses (85.6% response rate). Image-guided intensity modulated radiation therapy was given in 85.0% of patients and 3-dimensional conformal radiation therapy in 15.0%. Doses received included 73.8 Gy (34.5% patients), 74 Gy (53.6%), and 76 Gy (10.9%). Neoadjuvant androgen deprivation (AD) was given in 51.8% of patients and both neoadjuvant and adjuvant AD in 34.5%. The median follow-up time was 23 months (range, 12-67 months). In all, 3.8% of patients expressed DR for their choice of treatment. When asked whether they would choose DE-RT or AD again, only 0.5% probably or definitely would not choose DE-RT again, compared with 8.4% for AD (P<.01). Few patients treated with modern DE-RT express DR, with regret appearing to be lower than in previously published reports of patients treated with radical prostatectomy or older radiation therapy techniques. Patients experienced more regret with the AD component of treatment than with the radiation therapy component, with implications for informed consent. Further research should investigate regret associated with individual components of modern therapy, including AD, radiation therapy and surgery. Crown Copyright © 2013. Published by Elsevier Inc. All rights reserved.

Decision Regret in Men Undergoing Dose-Escalated Radiation Therapy for Prostate Cancer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Steer, Anna N.; Aherne, Noel J., E-mail: noel.aherne@ncahs.health.nsw.gov.au; Rural Clinical School Faculty of Medicine, University of New South Wales, Coffs Harbour

2013-07-15

Purpose: Decision regret (DR) is a negative emotion associated with medical treatment decisions, and it is an important patient-centered outcome after therapy for localized prostate cancer. DR has been found to occur in up to 53% of patients treated for localized prostate cancer, and it may vary depending on treatment modality. DR after modern dose-escalated radiation therapy (DE-RT) has not been investigated previously, to our knowledge. Our primary aim was to evaluate DR in a cohort of patients treated with DE-RT. Methods and Materials: We surveyed 257 consecutive patients with localized prostate cancer who had previously received DE-RT, by meansmore » of a validated questionnaire. Results: There were 220 responses (85.6% response rate). Image-guided intensity modulated radiation therapy was given in 85.0% of patients and 3-dimensional conformal radiation therapy in 15.0%. Doses received included 73.8 Gy (34.5% patients), 74 Gy (53.6%), and 76 Gy (10.9%). Neoadjuvant androgen deprivation (AD) was given in 51.8% of patients and both neoadjuvant and adjuvant AD in 34.5%. The median follow-up time was 23 months (range, 12-67 months). In all, 3.8% of patients expressed DR for their choice of treatment. When asked whether they would choose DE-RT or AD again, only 0.5% probably or definitely would not choose DE-RT again, compared with 8.4% for AD (P<.01). Conclusion: Few patients treated with modern DE-RT express DR, with regret appearing to be lower than in previously published reports of patients treated with radical prostatectomy or older radiation therapy techniques. Patients experienced more regret with the AD component of treatment than with the radiation therapy component, with implications for informed consent. Further research should investigate regret associated with individual components of modern therapy, including AD, radiation therapy and surgery.« less

Combination of magnetic resonance imaging and diffuse optical spectroscopy to predict radiation response in the breast: an exploratory pilot study

NASA Astrophysics Data System (ADS)

Klifa, C.; Hattangadi, J.; Watkins, M.; Li, A.; Sakata, T.; Tromberg, B.; Hylton, N.; Park, C.

2007-02-01

Radiation therapy (RT) is a standard treatment after lumpectomy for breast cancer, involving a typical course of approximately 6-7 weeks of daily treatment. Many women find this cumbersome and costly, and therefore many are left with the option of mastectomy. Many groups are now investigating novel ways to deliver RT, by using different techniques and shortening the course of treatment. However, the efficacy and side effects of these strategies are not known. In this project, we wish to develop noninvasive imaging tools that would allow us to measure radiation dose effects in women with breast cancer. We hope this will lead to new ways to identify individuals who may not need radiation therapy, who may safely be treated with new accelerated techniques, or who should be treated with the standard radiation therapy approach. We propose to study the effect of radiation therapy using a combination of two imaging modalities: 1) magnetic resonance imaging (MRI) which will provide detailed information on breast structures and blood vessels and 2) near infra-red diffuse optical spectroscopy (DOS), which measures local biologic properties of breast tissue. Our hypothesis is that by using a combination of modalities we will be able to better characterize radiation effects in breast tissue, by measuring differences between the radiated and non-irradiated breast. The development of novel non-invasive tools providing information about how individuals respond to radiation therapy can lead to important improvement of radiation treatment, and ultimately help guide individualized treatment programs in the future.

Number of Radiation Oncologists in Korea, Adequate or Surplus?

PubMed Central

2006-01-01

Purpose The purpose of this research is to discern and address the issues related to the radiation oncology manpower supply and its distribution. Materials and Methods The statistical data of the Annual Report of the Korea Central Cancer Registry (KCCR) from 1997 to 2002 and the Annual Report of the Korean Society of Radiation Oncology (KOSTRO) from 1997 to 2004 were used to predict the status of the human resources in 2015. The estimated demand and supply were calculated with the Microsoft Excel® program (Microsoft, Redmond, WA). Results The demand for radiation oncologists is estimated to be 161 in 2015 and about 4.9 radiation oncologists will be in demand annually. In contrast, an average of 15 new radiation oncologists will be supplied annually so that the accumulated surplus of radiation oncologists until 2015 is estimated to be 74.1. The main reason for the surplus comes from the discrepancy between the increased number of radiation therapy patients and the need for radiation oncologists. When there is an increase of 1,000 radiation therapy patients, the demand for radiation oncologists increases only by 2.4. This phenomenon is especially evident in the top 10 hospitals where the average number of radiation therapy patients per radiation oncologist is 341, which is 58% higher than the average number (215) of other 46 hospitals. Conclusion To prevent a surplus and to maintain the quality of management, the number of radiation therapy patients per radiation oncologist should be limited. Furthermore, coordinate control of the number of residency positions should be seriously considered. PMID:19771261

Whole-brain hippocampal sparing radiation therapy: Volume-modulated arc therapy vs intensity-modulated radiation therapy case study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, Katrina, E-mail: Trinabena23@gmail.com; Lenards, Nishele; Holson, Janice

The hippocampus is responsible for memory and cognitive function. An ongoing phase II clinical trial suggests that sparing dose to the hippocampus during whole-brain radiation therapy can help preserve a patient's neurocognitive function. Progressive research and advancements in treatment techniques have made treatment planning more sophisticated but beneficial for patients undergoing treatment. The aim of this study is to evaluate and compare hippocampal sparing whole-brain (HS-WB) radiation therapy treatment planning techniques using volume-modulated arc therapy (VMAT) and intensity-modulated radiation therapy (IMRT). We randomly selected 3 patients to compare different treatment techniques that could be used for reducing dose to themore » hippocampal region. We created 2 treatment plans, a VMAT and an IMRT, from each patient's data set and planned on the Eclipse 11.0 treatment planning system (TPS). A total of 6 plans (3 IMRT and 3 VMAT) were created and evaluated for this case study. The physician contoured the hippocampus as per the Radiation Therapy Oncology Group (RTOG) 0933 protocol atlas. The organs at risk (OR) were contoured and evaluated for the plan comparison, which included the spinal cord, optic chiasm, the right and left eyes, lenses, and optic nerves. Both treatment plans produced adequate coverage on the planning target volume (PTV) while significantly reducing dose to the hippocampal region. The VMAT treatment plans produced a more homogenous dose distribution throughout the PTV while decreasing the maximum point dose to the target. However, both treatment techniques demonstrated hippocampal sparing when irradiating the whole brain.« less

Mesenchymal Stem Cell Therapy for Acute Radiation Syndrome: Innovative Medical Approaches in Military Medicine

DTIC Science & Technology

2015-01-30

mesenchymal stem cells . Cytokine Growth Factor Rev. 2009;20:419–27. 8. Wang L, Li Y, Chen X, Chen J, Gautam SC, Xu Y, et al. MCP...Literature 3. DATES COVERED (From - To) 4. TITLE AND SUBTITLE Mesenchymal stem cell therapy for acute radiation syndrome: innovative medical...Independent Research Program 14. ABSTRACT See reprint. 15. SUBJECT TERMS Acute radiation syndrome, Mesenchymal stem cell , cell therapy,

Resectable Pediatric Nonrhabdomyosarcoma Soft Tissue Sarcoma: Which Patients Benefit from Adjuvant Radiation Therapy and How Much?

PubMed Central

Million, Lynn; Donaldson, Sarah S.

2012-01-01

It remains unclear which children and adolescents with resected nonrhabdomyosarcoma soft tissue sarcoma (NRSTS) benefit from radiation therapy, as well as the optimal dose, volume, and timing of radiotherapy when used with primary surgical resection. This paper reviews the sparse literature from clinical trials and retrospective studies of resected pediatric NRSTS to discern local recurrence rates in relationship to the use of radiation therapy. PMID:22523704

Nursing care update: Internal radiation therapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lowdermilk, D.L.

Internal radiation therapy has been used in treating gynecological cancers for over 100 years. A variety of radioactive sources are currently used alone and in combination with other cancer treatments. Nurses need to be able to provide safe, comprehensive care to patients receiving internal radiation therapy while using precautions to keep the risks of exposure to a minimum. This article discusses current trends and issues related to such treatment for gynecological cancers.20 references.

Late recurrence of nonseminomatous germ cell tumor successfully treated with intensity-modulated radiation therapy.

PubMed

Kita, Yuki; Imamura, Masaaki; Mizowaki, Takashi; Norihisa, Yoshiki; Yoshimura, Koji; Hiraoka, Masahiro; Ogawa, Osamu

2013-08-01

We report the case of a 41-year-old man with a late recurrence of nonseminomatous germ cell tumor, which was successfully treated with intensity-modulated radiation therapy. For the residual retrocrural tumor invading the 11th and 12th thoracic vertebrae with an abnormal level of tumor marker (α-fetoprotein: 23.2 ng/ml) after salvage chemotherapy, chemotherapy could not be continued due to its neurotoxicity, and surgery could not be performed due to the location. In this situation, intensity-modulated radiation therapy achieved a complete response of tumor marker. The patient remained in complete clinical remission after 3 years. The efficacy of radiotherapy, especially intensity-modulated radiation therapy, for a nonseminomatous germ cell tumor is discussed.

Trial Watch: Immunotherapy plus radiation therapy for oncological indications.

PubMed

Vacchelli, Erika; Bloy, Norma; Aranda, Fernando; Buqué, Aitziber; Cremer, Isabelle; Demaria, Sandra; Eggermont, Alexander; Formenti, Silvia Chiara; Fridman, Wolf Hervé; Fucikova, Jitka; Galon, Jérôme; Spisek, Radek; Tartour, Eric; Zitvogel, Laurence; Kroemer, Guido; Galluzzi, Lorenzo

2016-01-01

Malignant cells succumbing to some forms of radiation therapy are particularly immunogenic and hence can initiate a therapeutically relevant adaptive immune response. This reflects the intrinsic antigenicity of malignant cells (which often synthesize a high number of potentially reactive neo-antigens) coupled with the ability of radiation therapy to boost the adjuvanticity of cell death as it stimulates the release of endogenous adjuvants from dying cells. Thus, radiation therapy has been intensively investigated for its capacity to improve the therapeutic profile of several anticancer immunotherapies, including (but not limited to) checkpoint blockers, anticancer vaccines, oncolytic viruses, Toll-like receptor (TLR) agonists, cytokines, and several small molecules with immunostimulatory effects. Here, we summarize recent preclinical and clinical advances in this field of investigation.

Effects of radiation therapy on the lung: radiologic appearances and differential diagnosis.

PubMed

Choi, Yo Won; Munden, Reginald F; Erasmus, Jeremy J; Park, Kyung Joo; Chung, Woo Kyung; Jeon, Seok Chol; Park, Choong-Ki

2004-01-01

Radiation-induced lung disease (RILD) due to radiation therapy is common. Radiologic manifestations are usually confined to the lung tissue within the radiation port and are dependent on the interval after completion of treatment. In the acute phase, RILD typically manifests as ground-glass opacity or attenuation or as consolidation; in the late phase, it typically manifests as traction bronchiectasis, volume loss, and scarring. However, the use of oblique beam angles and the development of newer irradiation techniques such as three-dimensional conformal radiation therapy can result in an unusual distribution of these findings. Awareness of the atypical manifestations of RILD can be useful in preventing confusion with infection, recurrent malignancy, lymphangitic carcinomatosis, and radiation-induced tumors. In addition, knowledge of radiologic findings that are outside the expected pattern for RILD can be useful in diagnosis of infection or recurrent malignancy. Such findings include the late appearance or enlargement of a pleural effusion; development of consolidation, a mass, or cavitation; and occlusion of bronchi within an area of radiation-induced fibrosis. A comprehensive understanding of the full spectrum of these manifestations is important to facilitate diagnosis and management in cancer patients treated with radiation therapy. Copyright RSNA, 2004

Two-and-a-half-year clinical experience with the world's first magnetic resonance image guided radiation therapy system.

PubMed

Fischer-Valuck, Benjamin W; Henke, Lauren; Green, Olga; Kashani, Rojano; Acharya, Sahaja; Bradley, Jeffrey D; Robinson, Clifford G; Thomas, Maria; Zoberi, Imran; Thorstad, Wade; Gay, Hiram; Huang, Jiayi; Roach, Michael; Rodriguez, Vivian; Santanam, Lakshmi; Li, Harold; Li, Hua; Contreras, Jessika; Mazur, Thomas; Hallahan, Dennis; Olsen, Jeffrey R; Parikh, Parag; Mutic, Sasa; Michalski, Jeff

2017-01-01

Magnetic resonance image guided radiation therapy (MR-IGRT) has been used at our institution since 2014. We report on more than 2 years of clinical experience in treating patients with the world's first MR-IGRT system. A clinical service was opened for MR-IGRT in January 2014 with an MR-IGRT system consisting of a split 0.35T magnetic resonance scanner that straddles a ring gantry with 3 multileaf collimator-equipped 60 Co heads. The service was expanded to include online adaptive radiation therapy (ART) MR-IGRT and cine gating after 6 and 9 months, respectively. Patients selected for MR-IGRT were enrolled in a prospective registry between January 2014 and June 2016. Patients were treated with a variety of radiation therapy techniques including intensity modulated radiation therapy and stereotactic body radiation therapy (SBRT). When applicable, online ART was performed and gating on sagittal 2-dimensional cine MR was used. The charts of patients treated with MR-IGRT were reviewed to report on the clinical and treatment characteristics of the initial patients who were treated with this novel technique. A total of 316 patients have been treated with the MR-IGRT system, which has been integrated into a high-volume clinic. The cases were most commonly selected for improved soft tissue visualization, ART, and cine gating. Seventy-six patients were treated with 3-dimensional conformal radiation therapy, 146 patients with intensity modulated radiation therapy, and 94 patients with SBRT. The most commonly treated disease sites were the abdomen (28%), breast (26%), pelvis (22%), thorax (19%), and head and neck (5%). Sixty-seven patients were treated with online ART over a total of 244 adapted fractions. Cine treatment gating was used for a total of 81 patients. MR-IGRT has been successfully implemented in a high-volume radiation clinic and provides unique advantages in the treatment of a variety of malignancies. Additional clinical trials are in development to formally evaluate MR-IGRT in the treatment of multiple disease sites with techniques such as SBRT and ART.

Numerical investigation for entropy generation in hydromagnetic flow of fluid with variable properties and slip

NASA Astrophysics Data System (ADS)

Khan, M. Ijaz; Hayat, Tasawar; Alsaedi, Ahmed

2018-02-01

This modeling and computations present the study of viscous fluid flow with variable properties by a rotating stretchable disk. Rotating flow is generated through nonlinear rotating stretching surface. Nonlinear thermal radiation and heat generation/absorption are studied. Flow is conducting for a constant applied magnetic field. No polarization is taken. Induced magnetic field is not taken into account. Attention is focused on the entropy generation rate and Bejan number. The entropy generation rate and Bejan number clearly depend on velocity and thermal fields. The von Kármán approach is utilized to convert the partial differential expressions into ordinary ones. These expressions are non-dimensionalized, and numerical results are obtained for flow variables. The effects of the magnetic parameter, Prandtl number, radiative parameter, heat generation/absorption parameter, and slip parameter on velocity and temperature fields as well as the entropy generation rate and Bejan number are discussed. Drag forces (radial and tangential) and heat transfer rates are calculated and discussed. Furthermore the entropy generation rate is a decreasing function of magnetic variable and Reynolds number. The Bejan number effect on the entropy generation rate is reverse to that of the magnetic variable. Also opposite behavior of heat transfers is observed for varying estimations of radiative and slip variables.

Cord blood-derived cytokine-induced killer cellular therapy plus radiation therapy for esophageal cancer: a case report.

PubMed

Wang, Liming; Huang, Shigao; Dang, Yazheng; Li, Ming; Bai, Wen; Zhong, Zhanqiang; Zhao, Hongliang; Li, Yang; Liu, Yongjun; Wu, Mingyuan

2014-12-01

Esophageal cancer is a serious malignancy with regards to mortality and prognosis. Current treatment options include multimodality therapy mainstays of current treatment including surgery, radiation, and chemotherapy. Cell therapy for esophageal cancer is an advancing area of research. We report a case of esophageal cancer following cord blood-derived cytokine-induced killer cell infusion and adjuvant radiotherapy. Initially, she presented with poor spirit, full liquid diets, and upper abdominal pain. Through cell therapy plus adjuvant radiotherapy, the patient remitted and was self-reliant. Recognition of this curative effect of sequent therapy for esophageal cancer is important to enable appropriate treatment. This case highlights cord blood-derived cytokine-induced killer cell therapy significantly alleviates the adverse reaction of radiation and improves the curative effect. Cell therapy plus adjuvant radiotherapy can be a safe and effective treatment for esophageal cancer.

Medical Physics Challenges for the Implementation of Quality Assurance Programmes in Radiation Oncology.

PubMed

Meghzifene, A

2017-02-01

The importance of quality assurance in radiation therapy, as well as its positive consequences on patient treatment outcome, is well known to radiation therapy professionals. In low- and middle-income countries, the implementation of quality assurance in radiation therapy is especially challenging, due to a lack of staff training, a lack of national guidelines, a lack of quality assurance equipment and high patient daily throughput. According to the International Atomic Energy Agency (IAEA) Directory of Radiotherapy Centres, the proportion of linear accelerators compared with Co-60 machines has increased significantly in recent years in low- and middle-income countries. However, this increase in the proportion of relatively more demanding technology is not always accompanied with the necessary investment in staff training and quality assurance. The IAEA provides supports to low- and middle-income countries to develop and strengthen quality assurance programmes at institutional and national level. It also provides guidance, through its publications, on quality assurance and supports implementation of comprehensive clinical audits to identify gaps and makes recommendations for quality improvement in radiation therapy. The new AAPM TG100 report suggests a new approach to quality management in radiation therapy. If implemented, it will lead to improved cost-effectiveness of radiation therapy in all income settings. Low- and middle-income countries could greatly benefit from this new approach as it will help direct their scarce resources to areas where they can produce the optimum impact on patient care, without compromising patient safety. Copyright © 2016. Published by Elsevier Ltd.

Estimation of the risk of secondary malignancy arising from whole-breast irradiation: comparison of five radiotherapy modalities, including TomoHDA.

PubMed

Han, Eun Young; Paudel, Nava; Sung, Jiwon; Yoon, Myonggeun; Chung, Weon Kuu; Kim, Dong Wook

2016-04-19

The risk of secondary cancer from radiation treatment remains a concern for long-term breast cancer survivors, especially those treated with radiation at the age younger than 45 years. Treatment modalities optimally maximize the dose delivery to the tumor while minimizing radiation doses to neighboring organs, which can lead to secondary cancers. A new TomoTherapy treatment machine, TomoHDATM, can treat an entire breast with two static but intensity-modulated beams in a slice-by-slice fashion. This feature could reduce scattered and leakage radiation doses. We compared the plan quality and lifetime attributable risk (LAR) of a second malignancy among five treatment modalities: three-dimensional conformal radiation therapy, field-in-field forward-planned intensity-modulated radiation therapy, inverse-planned intensity-modulated radiation therapy (IMRT), volumetric modulated arc therapy, and TomoDirect mode on the TomoHDA system. Ten breast cancer patients were selected for retrospective analysis. Organ equivalent doses, plan characteristics, and LARs were compared. Out-of-field organ doses were measured with radio-photoluminescence glass dosimeters. Although the IMRT plan provided overall better plan quality, including the lowest probability of pneumonitis, it caused the second highest LAR. The TomoTherapy plan provided plan quality comparable to the IMRT plan and posed the lowest total LAR to neighboring organs. Therefore, it can be a better treatment modality for younger patients who have a longer life expectancy.

Surgery versus radiation therapy as single-modality treatment of tonsillar fossa carcinoma: the Roswell Park Cancer Institute experience (1971-1991).

PubMed

Hicks, W L; Kuriakose, M A; Loree, T R; Orner, J B; Schwartz, G; Mullins, A; Donaldson, C; Winston, J M; Bakamjian, V Y

1998-07-01

To compare the efficacy and treatment outcomes in patients with tonsillar fossa cancer using surgery or radiation as a single modality therapy. From 1971 to 1991 239 patients with oral pharyngeal cancer were treated at Roswell Park Cancer Institute. Of these patients 90 had tonsillar carcinoma. Seventy-six of these patients received either surgery (SA) (n = 56) or radiation therapy (RA) (n = 20) as single-modality therapy and are the subject of this review. All patients in the radiation arm of this review were surgical candidates who declined primary surgical therapy. Sixty-three percent of the SA and 80% of the RA treatment groups presented with either stage III or stage IV disease (P < or = .05). Forty-seven percent of the SA group and 52% of the RA patients had clinically positive regional disease at initial presentation. There was a predictable pattern of nodal presentation, with level II the most frequently involved region. The rate of occult metastasis was 27% and was evenly distributed between T1 and T4 disease. The overall local control rate in the SA group was 75%, compared with 60% in the RA group (P value was not significant). The disease-specific survival (all stages) was 61% in the SA group and 37% in the RA group (P < or = .05). The disease-free survival for stage III and stage IV disease in the SA group was 47% and in the RA group 27% (P < or = .05). Survival measured against clinical response to radiation therapy, in complete responders (all stages) was 83%; by contrast there were no survivors past 24 months in the partial response group (P < or = .001). The results from this study suggest that for early disease (stage I/II), surgery or radiation therapy as single-modality treatment is equally effective. For advanced disease radiation therapy is inferior to surgery as a single-modality treatment, as measured by ultimate survival and the local control of disease. There is, however, a subset of patients with advanced disease who respond to radiation therapy and whose survival is equivalent to our surgical cohort of patients.

Hypofractionated IMRT of the Prostate Bed After Radical Prostatectomy: Acute Toxicity in the PRIAMOS-1 Trial

DOE Office of Scientific and Technical Information (OSTI.GOV)

Katayama, Sonja, E-mail: sonja.katayama@med.uni-heidelberg.de; Striecker, Thorbjoern; Kessel, Kerstin

Purpose: Hypofractionated radiation therapy as primary treatment for prostate cancer is currently being investigated in large phase 3 trials. However, there are few data on postoperative hypofractionation. The Radiation therapy for the Prostate Bed With or Without the Pelvic Lymph Nodes (PRIAMOS 1) trial was initiated as a prospective phase 2 trial to assess treatment safety and toxicity of a hypofractionated intensity modulated radiation therapy (IMRT) of the prostate bed. Methods and Materials: From February to September 2012, 40 patients with indications for adjuvant or salvage radiation therapy were enrolled. One patient dropped out before treatment. Patients received 54 Gy inmore » 18 fractions to the prostate bed with IMRT and daily image guidance. Gastrointestinal (GI) and genitourinary (GU) toxicities (according to National Cancer Institute Common Terminology Criteria for Adverse Events, version 4.0) were recorded weekly during treatment and 10 weeks after radiation therapy. Results: Overall acute toxicity was favorable, with no recorded adverse events grade ≥3. Acute GI toxicity rates were 56.4% (grade 1) and 17.9% (grade 2). Acute GU toxicity was recorded in 35.9% of patients (maximum grade 1). Urinary stress incontinence was not influenced by radiation therapy. The incidence of grade 1 urinary urge incontinence increased from 2.6% before to 23.1% 10 weeks after therapy, but grade 2 urge incontinence remained unchanged. Conclusions: Postoperative hypofractionated IMRT of the prostate bed is tolerated well, with no severe acute side effects.« less

Long-term success of dental implants in patients with head and neck cancer after radiation therapy.

PubMed

Curi, M M; Condezo, A F B; Ribeiro, K D C B; Cardoso, C L

2018-06-01

The purpose of this study was to analyze the long-term success and factors potentially influencing the success of dental implants placed in patients with head and neck cancer who underwent radiation therapy with a minimum total dose of 50Gy during the years 1995-2010. Thirty-five patients (169 dental implants) were included in this study. Data on demographic characteristics, tumour type, radiation therapy, implant sites, implant dimensions, and hyperbaric oxygen therapy (HBOT) were obtained from the medical records and analyzed. Implant survival was estimated using Kaplan-Meier survival curves. Seventy-nine dental implants were placed in the maxilla and 90 in the mandible. The mean follow-up after implant installation was 7.4 years (range 0.3-14.7 years). The overall 5-year survival rate for all implants was 92.9%. Sex (P<0.001) and the mode of radiation therapy delivery (P=0.005) had a statistically significant influence on implant survival. Age, time of implantation after irradiation, implant brand and dimensions, and HBOT had no statistically significant influence on implant survival. Osseointegrated dental implants can be used successfully in the oral rehabilitation of patients with head and neck cancer with a history of radiation therapy. Risk factors such as sex and the mode of radiation therapy delivery can affect implant survival. Copyright © 2018 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

Basics of particle therapy I: physics

PubMed Central

Park, Seo Hyun

2011-01-01

With the advance of modern radiation therapy technique, radiation dose conformation and dose distribution have improved dramatically. However, the progress does not completely fulfill the goal of cancer treatment such as improved local control or survival. The discordances with the clinical results are from the biophysical nature of photon, which is the main source of radiation therapy in current field, with the lower linear energy transfer to the target. As part of a natural progression, there recently has been a resurgence of interest in particle therapy, specifically using heavy charged particles, because these kinds of radiations serve theoretical advantages in both biological and physical aspects. The Korean government is to set up a heavy charged particle facility in Korea Institute of Radiological & Medical Sciences. This review introduces some of the elementary physics of the various particles for the sake of Korean radiation oncologists' interest. PMID:22984664

Genital condyloma virus infection following pelvic radiation therapy: report of seven cases

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lowell, D.M.; Livolsi, V.A.; Ludwig, M.E.

1983-01-01

Six women who underwent radiation therapy for gynecologic malignancies demonstrated cytologic evidence of condyloma virus infection 2 or more years following radiation. Histologic confirmation was obtained in two of the cases. A seventh patient developed in situ and invasive squamous cell carcinoma in a vulvar condyloma acuminatum following radiation therapy for Hodgkin's disease. This venereal infection is found most frequently in sexually active younger women (average age, 27 years). It is felt that depressed cell-mediated immunity consequent to the radiation therapy allowed the development of this infection in the older patients described in this report. The evolution of invasive squamousmore » cell carcinoma in the condyloma acuminatum may indicate a possible oncogenic or cocarcinogenic effect of the virus. The immunologic responses to infection caused by the human papillomavirus group are discussed, as well as its potential for malignant transformation.« less

Misadministration of radiation therapy in veterinary medicine: a case report and literature review.

PubMed

Arkans, M M; Gieger, T L; Nolan, M W

2017-03-01

Recent technical advancements in radiation therapy have allowed for improved targeting of tumours and sparing nearby normal tissues, while simultaneously decreasing the risk for medical errors by incorporating additional safety checks into electronic medical record keeping systems. The benefits of these new technologies, however, depends on their proper integration and use in the oncology clinic. Despite the advancement of technology for treatment delivery and medical record keeping, misadministration errors have a significant impact on patient care in veterinary oncology. The first part of this manuscript describes a medical incident that occurred at an academic veterinary referral hospital, in a dog receiving a combination of stereotactic radiation therapy and full-course intensity-modulated, image-guided radiation therapy. The second part of the report is a literature review, which explores misadministration errors and novel challenges which arise with the implementation of advancing technologies in veterinary radiation oncology. © 2015 John Wiley & Sons Ltd.

The PEREGRINETM program: using physics and computer simulation to improve radiation therapy for cancer

NASA Astrophysics Data System (ADS)

Hartmann Siantar, Christine L.; Moses, Edward I.

1998-11-01

When using radiation to treat cancer, doctors rely on physics and computer technology to predict where the radiation dose will be deposited in the patient. The accuracy of computerized treatment planning plays a critical role in the ultimate success or failure of the radiation treatment. Inaccurate dose calculations can result in either insufficient radiation for cure, or excessive radiation to nearby healthy tissue, which can reduce the patient's quality of life. This paper describes how advanced physics, computer, and engineering techniques originally developed for nuclear weapons and high-energy physics research are being used to predict radiation dose in cancer patients. Results for radiation therapy planning, achieved in the Lawrence Livermore National Laboratory (LLNL) 0143-0807/19/6/005/img2 program show that these tools can give doctors new insights into their patients' treatments by providing substantially more accurate dose distributions than have been available in the past. It is believed that greater accuracy in radiation therapy treatment planning will save lives by improving doctors' ability to target radiation to the tumour and reduce suffering by reducing the incidence of radiation-induced complications.

A critical appraisal of the clinical utility of proton therapy in oncology

PubMed Central

Wang, Dongxu

2015-01-01

Proton therapy is an emerging technology for providing radiation therapy to cancer patients. The depth dose distribution of a proton beam makes it a preferable radiation modality as it reduces radiation to the healthy tissue outside the tumor, compared with conventional photon therapy. While theoretically beneficial, its clinical values are still being demonstrated from the increasing number of patients treated with proton therapy, from several dozen proton therapy centers around the world. High equipment and facility costs are often the major obstacle for its wider adoption. Because of the high cost and lack of definite clinical evidence of its superiority, proton therapy treatment faces criticism on its cost-effectiveness. Technological development is causing a gradual lowering of costs, and research and clinical studies are providing further evidence on its clinical utility. PMID:26604838

Adding chemo after radiation treatment improves survival for adults with a type of brain tumor

Cancer.gov

Adults with low-grade gliomas, a form of brain tumor, who received chemotherapy following completion of radiation therapy lived longer than patients who received radiation therapy alone, according to long-term follow-up results from a NIH-supported random

Managing Radiation Therapy Side Effects: What to Do about Feeling Sick to Your Stomach and Throwing Up (Nausea and ...

MedlinePlus

... because it makes them feel sick. ■ ■ Listen to music or an audiobook before treatment, to help relax. ... livehelp NCI has a series of 9 Radiation Therapy Side Effects Sheets at: www.cancer.gov/radiation- ...

Phase I study of liposome-encapsulated c-raf antisense oligodeoxyribonucleotide infusion in combination with radiation therapy in patients with advanced malignancies.

PubMed

Dritschilo, Anatoly; Huang, Chao H; Rudin, Charles M; Marshall, John; Collins, Brian; Dul, Jeanne L; Zhang, Chuanbo; Kumar, Deepak; Gokhale, Prafulla C; Ahmad, Ateeq; Ahmad, Imran; Sherman, Jeffrey W; Kasid, Usha N

2006-02-15

Raf proteins are key elements of growth-related cellular signaling pathways and are a component of cancer cell resistance to radiation therapy. Antisense oligonucleotides to c-raf-1 permit highly selective inhibition of the gene product and offer a strategy for sensitizing cancer cells to radiation therapy. In this dose escalation study, we evaluated the safety of combined liposomal formulation of raf antisense oligonucleotide (LErafAON) and radiation therapy in patients with advanced malignancies. Patients with advanced solid tumors were treated with LErafAON in a phase I dose escalation study while receiving palliative radiation therapy. Drug-related and radiation-related toxicities were monitored. Pharmacokinetics and expression of c-raf-1 mRNA and Raf-1 protein were determined in peripheral blood mononuclear cells. Seventeen patients with palliative indications for radiation therapy were entered into this study. Thirteen patients received daily infusions of LErafAON and four received twice-weekly infusions. Radiation therapy was delivered in daily 300-cGy fractions over 2 weeks. Patients tolerated radiation, and no unexpected radiation-related side effects were observed. Drug-related reactions (grade > or =2), such as back pain, chills, dyspnea, fatigue, fever, flushing, and hypertension, were observed in most patients and were managed by premedication with corticosteroids and antihistamines. Serious adverse events occurred in five patients, including acute infusion-related symptoms, abnormal liver function tests, hypoxia, dehydration, diarrhea, esophagitis, fever, hypokalemia, pharyngitis, and tachypnea. Twelve of 17 patients were evaluable for tumor response at completion of treatment; four showed partial response, four showed stable disease, and four experienced progressive disease. The intact rafAON was detected in plasma for 30 minutes to several hours. Six patients with partial response or stable disease were evaluable for c-raf-1 mRNA and/or Raf-1 protein expression. Inhibition of c-raf-1 mRNA was observed in three of five patients. Raf-1 protein was inhibited in four of five patients. This is the first report of the combined modality treatment using antisense oligonucleotides with radiation therapy in patients with advanced cancer. A dose of 2.0 mg/kg of LErafAON administered twice weekly is tolerated with premedication and does not enhance radiation toxicity in patients. The observation of dose-dependent, infusion-related reactions has led to further modification of the liposomal composition for use in future clinical trials.

Advances in radiation oncology for the management of oropharyngeal tumors.

PubMed

Gunn, G Brandon; Frank, Steven J

2013-08-01

The major benefits of modern radiation therapy (eg, intensity-modulated [x-ray] radiation therapy [IMRT]) for oropharyngeal cancer are reduced xerostomia and better quality of life. Intensity-modulated proton therapy may provide additional advantages over IMRT by reducing radiation beam-path toxicities. Several acute and late treatment-related toxicities and symptom constellations must be kept in mind when designing and comparing future treatment strategies, particularly because currently most patients with oropharyngeal carcinoma present with human papillomavirus-positive disease and are expected to have a high probability of long-term survival after treatment. Copyright © 2013 Elsevier Inc. All rights reserved.

Intensity-modulated radiation therapy: a review with a physics perspective.

PubMed

Cho, Byungchul

2018-03-01

Intensity-modulated radiation therapy (IMRT) has been considered the most successful development in radiation oncology since the introduction of computed tomography into treatment planning that enabled three-dimensional conformal radiotherapy in 1980s. More than three decades have passed since the concept of inverse planning was first introduced in 1982, and IMRT has become the most important and common modality in radiation therapy. This review will present developments in inverse IMRT treatment planning and IMRT delivery using multileaf collimators, along with the associated key concepts. Other relevant issues and future perspectives are also presented.

Estimated Internal and External Radiation Exposure of Caregivers of Patients With Pediatric Neuroblastoma Undergoing 131I Metaiodobenzylguanidine Therapy: A Prospective Pilot Study.

PubMed

Han, Sangwon; Yoo, Seon Hee; Koh, Kyung-Nam; Lee, Jong Jin

2017-04-01

Current recommendations suggest that family members should participate in the care of children receiving in-hospital I metaiodobenzylguanidine (MIBG) therapy for neuroblastoma. The present study aimed to measure the external radiation exposure and estimate the internal radiation exposure of caregivers during the hospital stay for I MIBG therapy. Caregivers received radiation safety instructions and a potassium iodide solution for thyroid blockade before patient admission. External radiation exposure was determined using a personal pocket dosimeter. Serial 24-hour urine samples were collected from caregivers during the hospital stay. Estimated internal radiation exposure was calculated based on the urine activity. Twelve cases (mean age, 6.2 ± 3.5 years; range, 2-13 years) were enrolled. The mean administered activity was 233.3 ± 74.9 (range, 150.0-350.0) mCi. The mean external radiation dose was 5.8 ± 7.2 (range, 0.8-19.9) mSv. Caregivers of children older than 4 years had significantly less external radiation exposure than those of children younger than 4 years (1.9 ± 1.0 vs 16.4 ± 5.0 mSv; P = 0.012). The mean estimated internal radiation dose was 11.3 ± 10.2 (range, 1.0-29.8) μSv. Caregivers receive both external and internal radiation exposure while providing in-hospital care to children receiving I MIBG therapy for neuroblastoma. However, the internal radiation exposure was negligible compared with the external radiation exposure.

Development of a Multimarker Urine Test for Prostate Cancer

DTIC Science & Technology

2017-10-01

which can, for example, range dramatically from monitoring, in the case of low-risk cancers, to radiation or surgical procedures for higher risk...surgery, radiation , hormone therapy, chemotherapy, brachytherapy, cryotherapy, ultrasound, bisphosphate therapy, biologic 15 therapy, or vaccine therapy...a monokine involved in the acute inflammatory state of polymorphonuclear leukocyte recruitment and activation. CCL3 is expressed in many cell types

Unstable force analysis for induction motor eccentricity

NASA Astrophysics Data System (ADS)

Han, Xu; Palazzolo, Alan

2016-05-01

The increasing popularity of motors in machinery trains has led to an intensified interest in the forces they produce that may influence machinery vibration. Motor design typically assumes a uniform air gap, however in practice all motors operate with the rotor slightly displaced from the motor centerline in what is referred to as an eccentric position. Rotor center eccentricity can cause a radially unbalanced magnetic field when the motor is operating. This will results in both a radial force pulling the motor further away from the center, and a tangential force which can induce a vibration stability problem. In this paper, a magnetic equivalent circuit MEC modeling method is proposed to calculate both the radial and tangential motor eccentric force. The treatment of tangential force determination is rarely addressed, but it is very important for rotordynamic vibration stability evaluation. The proposed model is also coupled with the motor electric circuit model to provide capability for transient vibration simulations. FEM is used to verify the MEC model. A parametric study is performed on the motor radial and tangential eccentric forces. Also a Jeffcott rotor model is used to study the influence of the motor eccentric force on mechanical vibration stability and nonlinear behavior. Furthermore, a stability criteria for the bearing damping is provided. The motor radial and tangential eccentric forces are both curved fitted to include their nonlinearity in time domain transient simulation for both a Jeffcott rotor model and a geared machinery train with coupled torsional-lateral motion. Nonlinear motions are observed, including limit cycles and bifurcation induced vibration amplitude jumps.

Prehension synergies: A study of digit force adjustments to the continuously varied load force exerted on a partially constrained hand-held object

PubMed Central

Friedman, Jason; Latash, Mark L.; Zatsiorsky, Vladimir M.

2009-01-01

We examined how the digit forces adjust when a load force acting on a hand-held object continuously varies. The subjects were required to hold the handle still while a linearly increasing and then decreasing force was applied to the handle. The handle was constrained, such that it could only move up and down, and rotate about a horizontal axis. In addition the moment arm of the thumb tangential force was 1.5 times the moment arm of the virtual finger (VF, an imagined finger with the mechanical action equal to that of the four fingers) force. Unlike the situation when there are equal moment arms, the experimental setup forced the subjects to choose between (a) sharing equally the increase in load force between the thumb and virtual finger but generating a moment of tangential force, which had to be compensated by negatively covarying the moment due to normal forces, or (b) sharing unequally the load force increase between the thumb and VF but preventing generation of a moment of tangential forces. We found that different subjects tended to use one of these two strategies. These findings suggest that the selection by the CNS of prehension synergies at the VF-thumb level with respect to the moment of force are non-obligatory and reflect individual subject preferences. This unequal sharing of the load by the tangential forces, in contrast to the previously observed equal sharing, suggests that the invariant feature of prehension may be a correlated increase in tangential forces rather than an equal increase. PMID:19554319

Voice quality after treatment of early vocal cord cancer: a randomized trial comparing laser surgery with radiation therapy.

PubMed

Aaltonen, Leena-Maija; Rautiainen, Noora; Sellman, Jaana; Saarilahti, Kauko; Mäkitie, Antti; Rihkanen, Heikki; Laranne, Jussi; Kleemola, Leenamaija; Wigren, Tuija; Sala, Eeva; Lindholm, Paula; Grenman, Reidar; Joensuu, Heikki

2014-10-01

Early laryngeal cancer is usually treated with either transoral laser surgery or radiation therapy. The quality of voice achieved with these treatments has not been compared in a randomized trial. Male patients with carcinoma limited to 1 mobile vocal cord (T1aN0M0) were randomly assigned to receive either laser surgery (n=32) or external beam radiation therapy (n=28). Surgery consisted of tumor excision with a CO2 laser with the patient under general anaesthesia. External beam radiation therapy to the larynx was delivered to a cumulative dose of 66 Gy in 2-Gy daily fractions over 6.5 weeks. Voice quality was assessed at baseline and 6 and 24 months after treatment. The main outcome measures were expert-rated voice quality on a grade, roughness, breathiness, asthenia, and strain (GRBAS) scale, videolaryngostroboscopic findings, and the patients' self-rated voice quality and its impact on activities of daily living. Overall voice quality between the groups was rated similar, but voice was more breathy and the glottal gap was wider in patients treated with laser surgery than in those who received radiation therapy. Patients treated with radiation therapy reported less hoarseness-related inconvenience in daily living 2 years after treatment. Three patients in each group had local cancer recurrence within 2 years from randomization. Radiation therapy may be the treatment of choice for patients whose requirements for voice quality are demanding. Overall voice quality was similar in both treatment groups, however, indicating a need for careful consideration of patient-related factors in the choice of a treatment option. Copyright © 2014 Elsevier Inc. All rights reserved.

MR Imaging Evaluation of Intracerebral Hemorrhages and T2 Hyperintense White Matter Lesions Appearing after Radiation Therapy in Adult Patients with Primary Brain Tumors.

PubMed

Yoo, Dong Hyun; Song, Sang Woo; Yun, Tae Jin; Kim, Tae Min; Lee, Se-Hoon; Kim, Ji-Hoon; Sohn, Chul-Ho; Park, Sung-Hye; Park, Chul-Kee; Kim, Il Han; Choi, Seung Hong

2015-01-01

The purpose of our study was to determine the frequency and severity of intracerebral hemorrhages and T2 hyperintense white matter lesions (WMLs) following radiation therapy for brain tumors in adult patients. Of 648 adult brain tumor patients who received radiation therapy at our institute, magnetic resonance (MR) image data consisting of a gradient echo (GRE) and FLAIR T2-weighted image were available three and five years after radiation therapy in 81 patients. Intracerebral hemorrhage was defined as a hypointense dot lesion appearing on GRE images after radiation therapy. The number and size of the lesions were evaluated. The T2 hyperintense WMLs observed on the FLAIR sequences were graded according to the extent of the lesion. Intracerebral hemorrhage was detected in 21 (25.9%) and 35 (43.2) patients in the three- and five-year follow-up images, respectively. The number of intracerebral hemorrhages per patient tended to increase as the follow-up period increased, whereas the size of the intracerebral hemorrhages exhibited little variation over the course of follow-up. T2 hyperintense WMLs were observed in 27 (33.3%) and 32 (39.5) patients in the three and five year follow-up images, respectively. The age at the time of radiation therapy was significantly higher (p < 0.001) in the patients with T2 hyperintense WMLs than in those without lesions. Intracerebral hemorrhages are not uncommon in adult brain tumor patients undergoing radiation therapy. The incidence and number of intracerebral hemorrhages increased over the course of follow-up. T2 hyperintense WMLs were observed in more than one-third of the study population.

Better Efficacy of Synchrotron Spatially Microfractionated Radiation Therapy Than Uniform Radiation Therapy on Glioma.

PubMed

Bouchet, Audrey; Bräuer-Krisch, Elke; Prezado, Yolanda; El Atifi, Michèle; Rogalev, Léonid; Le Clec'h, Céline; Laissue, Jean Albert; Pelletier, Laurent; Le Duc, Géraldine

2016-08-01

Synchrotron microbeam radiation therapy (MRT) is based on the spatial fractionation of the incident, highly focused synchrotron beam into arrays of parallel microbeams, typically a few tens of microns wide and depositing several hundred grays. This irradiation modality was shown to have a high therapeutic impact on tumors, especially in intracranial locations. However, mechanisms responsible for such a property are not fully understood. Thanks to recent progress in dosimetry, we compared the effect of MRT and synchrotron broad beam (BB) radiation therapy delivered at comparable doses (equivalent to MRT valley dose) on tumor growth control and on classical radiobiological functions by histologic evaluation and/or transcriptomic analysis. MRT significantly improved survival of rats bearing 9L intracranial glioma compared with BB radiation therapy delivered at a comparable dose (P<.001); the efficacy of MRT and BB radiation therapy was similar when the MRT dose was half that of BB. The greater efficacy of MRT was not correlated with a difference in cell proliferation (Mki67 and proliferating cell nuclear antigen) or in transcriptomic stimulation of angiogenesis (vascular endothelial growth factor A or tyrosine kinase with immunoglobulin-like and epidermal growth factor-like domains 2) but was correlated with a higher cell death rate (factor for apoptosis signals) and higher recruitment of macrophages (tyrosine kinase with immunoglobulin-like and epidermal growth factor-like domains 1 and CD68 transcripts) a few days after MRT. These results show the superiority of MRT over BB radiation therapy when applied at comparable doses, suggesting that spatial fractionation is responsible for a specific and particularly efficient tissue response. The higher induction of cell death and immune cell activation in brain tumors treated by MRT may be involved in such responses. Copyright © 2016 Elsevier Inc. All rights reserved.

Information Needs of Older Women With Early-Stage Breast Cancer When Making Radiation Therapy Decisions.

PubMed

Wang, Shi-Yi; Kelly, Gabrielle; Gross, Cary; Killelea, Brigid K; Mougalian, Sarah; Presley, Carolyn; Fraenkel, Liana; Evans, Suzanne B

2017-07-15

To identify the information older women with early-stage breast cancer need when making radiation therapy decisions, and who patients identify as the main decision maker. We surveyed (through face-to-face interview, telephone, or mail) women aged ≥65 years who received lumpectomy and were considering or receiving adjuvant radiation therapy for early-stage breast cancer. The survey instrument was constructed with input from patient and professional advisory committees, including breast cancer survivors, advocates of breast cancer care and aging, clinicians, and researchers. Participants rated the importance (on a 4-point scale) of 24 statements describing the benefits, side effects, impact on daily life, and other issues of radiation therapy in relation to radiation therapy decision making. Participants also designated who was considered the key decision maker. The response rate was 56.4% (93 of 165). Mean age was 72.5 years, ranging from 65 to 93 years. More than 96% of participants indicated they were the main decision maker on receiving radiation therapy. There was wide variation in information needs regarding radiation therapy decision making. Participants rated a mean of 18 (range, 3-24) items as "essential." Participants rated items related to benefits highest, followed by side effects. Participants who were older than 75 years rated 13.9 questions as essential, whereas participants aged ≤74 years rated 18.7 as essential (P=.018). Older women desire information and have more agency and input in the decision-making process than prior literature would suggest. The variation in information needs indicates that future decision support tools should provide options to select what information would be of interest to the participants. Copyright © 2017 Elsevier Inc. All rights reserved.

Continuous Activity Monitoring During Concurrent Chemoradiotherapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ohri, Nitin, E-mail: ohri.nitin@gmail.com; Kabarriti, Rafi; Bodner, William R.

Purpose: To perform a prospective trial testing the feasibility and utility of acquiring activity data as a measure of health status during concurrent chemoradiotherapy. Methods and Materials: Ambulatory patients who were planned for treatment with concurrent chemoradiotherapy with curative intent for cancers of the head and neck, lung, or gastrointestinal tract were provided with activity monitors before treatment initiation. Patients were asked to wear the devices continuously throughout the radiation therapy course. Step count data were downloaded weekly during radiation therapy and 2 and 4 weeks after radiation therapy completion. The primary objective was to demonstrate feasibility, defined as collection ofmore » step counts for 80% of the days during study subjects' radiation therapy courses. Secondary objectives included establishing step count as a dynamic predictor of unplanned hospitalization risk. Results: Thirty-eight enrolled patients were treated with concurrent chemoradiotherapy. Primary diagnoses included head and neck cancer (n=11), lung cancer (n=13), and a variety of gastrointestinal cancers (n=14). Step data were collected for 1524 of 1613 days (94%) during patients' radiation therapy courses. Fourteen patients were hospitalized during radiation therapy or within 4 weeks of radiation therapy completion. Cox regression modeling demonstrated a significant association between recent step counts (3-day average) and hospitalization risk, with a 38% reduction in the risk of hospitalization for every 1000 steps taken each day (hazard ratio 0.62, 95% confidence interval 0.46-0.83, P=.002). Inferior quality of life scores and impaired performance status were not associated with increased hospitalization risk. Conclusion: Continuous activity monitoring during concurrent chemoradiotherapy is feasible and well-tolerated. Step counts may serve as powerful, objective, and dynamic indicators of hospitalization risk.« less

Better Efficacy of Synchrotron Spatially Microfractionated Radiation Therapy Than Uniform Radiation Therapy on Glioma

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bouchet, Audrey, E-mail: audrey.m.bouchet@gmail.com; Biomedical Beamline, European Synchrotron Radiation Facility, Grenoble; Bräuer-Krisch, Elke

Purpose: Synchrotron microbeam radiation therapy (MRT) is based on the spatial fractionation of the incident, highly focused synchrotron beam into arrays of parallel microbeams, typically a few tens of microns wide and depositing several hundred grays. This irradiation modality was shown to have a high therapeutic impact on tumors, especially in intracranial locations. However, mechanisms responsible for such a property are not fully understood. Methods and Materials: Thanks to recent progress in dosimetry, we compared the effect of MRT and synchrotron broad beam (BB) radiation therapy delivered at comparable doses (equivalent to MRT valley dose) on tumor growth control andmore » on classical radiobiological functions by histologic evaluation and/or transcriptomic analysis. Results: MRT significantly improved survival of rats bearing 9L intracranial glioma compared with BB radiation therapy delivered at a comparable dose (P<.001); the efficacy of MRT and BB radiation therapy was similar when the MRT dose was half that of BB. The greater efficacy of MRT was not correlated with a difference in cell proliferation (Mki67 and proliferating cell nuclear antigen) or in transcriptomic stimulation of angiogenesis (vascular endothelial growth factor A or tyrosine kinase with immunoglobulin-like and epidermal growth factor-like domains 2) but was correlated with a higher cell death rate (factor for apoptosis signals) and higher recruitment of macrophages (tyrosine kinase with immunoglobulin-like and epidermal growth factor-like domains 1 and CD68 transcripts) a few days after MRT. Conclusions: These results show the superiority of MRT over BB radiation therapy when applied at comparable doses, suggesting that spatial fractionation is responsible for a specific and particularly efficient tissue response. The higher induction of cell death and immune cell activation in brain tumors treated by MRT may be involved in such responses.« less

Measurements of the neutron dose equivalent for various radiation qualities, treatment machines and delivery techniques in radiation therapy

NASA Astrophysics Data System (ADS)

Hälg, R. A.; Besserer, J.; Boschung, M.; Mayer, S.; Lomax, A. J.; Schneider, U.

2014-05-01

In radiation therapy, high energy photon and proton beams cause the production of secondary neutrons. This leads to an unwanted dose contribution, which can be considerable for tissues outside of the target volume regarding the long term health of cancer patients. Due to the high biological effectiveness of neutrons in regards to cancer induction, small neutron doses can be important. This study quantified the neutron doses for different radiation therapy modalities. Most of the reports in the literature used neutron dose measurements free in air or on the surface of phantoms to estimate the amount of neutron dose to the patient. In this study, dose measurements were performed in terms of neutron dose equivalent inside an anthropomorphic phantom. The neutron dose equivalent was determined using track etch detectors as a function of the distance to the isocenter, as well as for radiation sensitive organs. The dose distributions were compared with respect to treatment techniques (3D-conformal, volumetric modulated arc therapy and intensity-modulated radiation therapy for photons; spot scanning and passive scattering for protons), therapy machines (Varian, Elekta and Siemens linear accelerators) and radiation quality (photons and protons). The neutron dose equivalent varied between 0.002 and 3 mSv per treatment gray over all measurements. Only small differences were found when comparing treatment techniques, but substantial differences were observed between the linear accelerator models. The neutron dose equivalent for proton therapy was higher than for photons in general and in particular for double-scattered protons. The overall neutron dose equivalent measured in this study was an order of magnitude lower than the stray dose of a treatment using 6 MV photons, suggesting that the contribution of the secondary neutron dose equivalent to the integral dose of a radiotherapy patient is small.

Prospective Randomized Comparison of the Effectiveness of Radiation Therapy and Local Steroid Injection for the Treatment of Plantar Fasciitis.

PubMed

Canyilmaz, Emine; Canyilmaz, Fatih; Aynaci, Ozlem; Colak, Fatma; Serdar, Lasif; Uslu, Gonca Hanedan; Aynaci, Osman; Yoney, Adnan

2015-07-01

The purpose of this study was to conduct a randomized trial of radiation therapy for plantar fasciitis and to compare radiation therapy with local steroid injections. Between March 2013 and April 2014, 128 patients with plantar fasciitis were randomized to receive radiation therapy (total dose of 6.0 Gy applied in 6 fractions of 1.0 Gy three times a week) or local corticosteroid injections a 1 ml injection of 40 mg methylprednisolone and 0.5 ml 1% lidocaine under the guidance of palpation. The results were measured using a visual analog scale, a modified von Pannewitz scale, and a 5-level function score. The fundamental phase of the study was 3 months, with a follow-up period of up to 6 months. The median follow-up period for all patients was 12.5 months (range, 6.5-18.6 months). For the radiation therapy patients, the median follow-up period was 13 months (range, 6.5-18.5 months), whereas in the palpation-guided (PG) steroid injection arm, it was 12.1 months (range, 6.5-18.6 months). After 3 months, results in the radiation therapy arm were significantly superior to those in the PG steroid injection arm (visual analog scale, P<.001; modified von Pannewitz scale, P<.001; 5-level function score, P<.001). Requirements for a second treatment did not significantly differ between the 2 groups, but the time interval for the second treatment was significantly shorter in the PG steroid injection group (P=.045). This study confirms the superior analgesic effect of radiation therapy compared to mean PG steroid injection on plantar fasciitis for at least 6 months after treatment. Copyright © 2015 Elsevier Inc. All rights reserved.

Radiation Therapy to the Plexus Brachialis in Breast Cancer Patients: Analysis of Paresthesia in Relation to Dose and Volume.

PubMed

Lundstedt, Dan; Gustafsson, Magnus; Steineck, Gunnar; Sundberg, Agnetha; Wilderäng, Ulrica; Holmberg, Erik; Johansson, Karl-Axel; Karlsson, Per

2015-06-01

To identify volume and dose predictors of paresthesia after irradiation of the brachial plexus among women treated for breast cancer. The women had breast surgery with axillary dissection, followed by radiation therapy with (n=192) or without irradiation (n=509) of the supraclavicular lymph nodes (SCLNs). The breast area was treated to 50 Gy in 2.0-Gy fractions, and 192 of the women also had 46 to 50 Gy to the SCLNs. We delineated the brachial plexus on 3-dimensional dose-planning computerized tomography. Three to eight years after radiation therapy the women answered a questionnaire. Irradiated volumes and doses were calculated and related to the occurrence of paresthesia in the hand. After treatment with axillary dissection with radiation therapy to the SCLNs 20% of the women reported paresthesia, compared with 13% after axillary dissection without radiation therapy, resulting in a relative risk (RR) of 1.47 (95% confidence interval [CI] 1.02-2.11). Paresthesia was reported by 25% after radiation therapy to the SCLNs with a V40 Gy ≥ 13.5 cm(3), compared with 13% without radiation therapy, RR 1.83 (95% CI 1.13-2.95). Women having a maximum dose to the brachial plexus of ≥55.0 Gy had a 25% occurrence of paresthesia, with RR 1.86 (95% CI 0.68-5.07, not significant). Our results indicate that there is a correlation between larger irradiated volumes of the brachial plexus and an increased risk of reported paresthesia among women treated for breast cancer. Copyright © 2015 Elsevier Inc. All rights reserved.

Voice Quality After Treatment of Early Vocal Cord Cancer: A Randomized Trial Comparing Laser Surgery With Radiation Therapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aaltonen, Leena-Maija, E-mail: leena-maija.aaltonen@hus.fi; Rautiainen, Noora; Sellman, Jaana

Objective: Early laryngeal cancer is usually treated with either transoral laser surgery or radiation therapy. The quality of voice achieved with these treatments has not been compared in a randomized trial. Methods and Materials: Male patients with carcinoma limited to 1 mobile vocal cord (T1aN0M0) were randomly assigned to receive either laser surgery (n=32) or external beam radiation therapy (n=28). Surgery consisted of tumor excision with a CO{sub 2} laser with the patient under general anaesthesia. External beam radiation therapy to the larynx was delivered to a cumulative dose of 66 Gy in 2-Gy daily fractions over 6.5 weeks. Voice quality wasmore » assessed at baseline and 6 and 24 months after treatment. The main outcome measures were expert-rated voice quality on a grade, roughness, breathiness, asthenia, and strain (GRBAS) scale, videolaryngostroboscopic findings, and the patients' self-rated voice quality and its impact on activities of daily living. Results: Overall voice quality between the groups was rated similar, but voice was more breathy and the glottal gap was wider in patients treated with laser surgery than in those who received radiation therapy. Patients treated with radiation therapy reported less hoarseness-related inconvenience in daily living 2 years after treatment. Three patients in each group had local cancer recurrence within 2 years from randomization. Conclusions: Radiation therapy may be the treatment of choice for patients whose requirements for voice quality are demanding. Overall voice quality was similar in both treatment groups, however, indicating a need for careful consideration of patient-related factors in the choice of a treatment option.« less

Measurements of the neutron dose equivalent for various radiation qualities, treatment machines and delivery techniques in radiation therapy.

PubMed

Hälg, R A; Besserer, J; Boschung, M; Mayer, S; Lomax, A J; Schneider, U

2014-05-21

In radiation therapy, high energy photon and proton beams cause the production of secondary neutrons. This leads to an unwanted dose contribution, which can be considerable for tissues outside of the target volume regarding the long term health of cancer patients. Due to the high biological effectiveness of neutrons in regards to cancer induction, small neutron doses can be important. This study quantified the neutron doses for different radiation therapy modalities. Most of the reports in the literature used neutron dose measurements free in air or on the surface of phantoms to estimate the amount of neutron dose to the patient. In this study, dose measurements were performed in terms of neutron dose equivalent inside an anthropomorphic phantom. The neutron dose equivalent was determined using track etch detectors as a function of the distance to the isocenter, as well as for radiation sensitive organs. The dose distributions were compared with respect to treatment techniques (3D-conformal, volumetric modulated arc therapy and intensity-modulated radiation therapy for photons; spot scanning and passive scattering for protons), therapy machines (Varian, Elekta and Siemens linear accelerators) and radiation quality (photons and protons). The neutron dose equivalent varied between 0.002 and 3 mSv per treatment gray over all measurements. Only small differences were found when comparing treatment techniques, but substantial differences were observed between the linear accelerator models. The neutron dose equivalent for proton therapy was higher than for photons in general and in particular for double-scattered protons. The overall neutron dose equivalent measured in this study was an order of magnitude lower than the stray dose of a treatment using 6 MV photons, suggesting that the contribution of the secondary neutron dose equivalent to the integral dose of a radiotherapy patient is small.

Ablative Hypofractionated Radiation Therapy Enhances Non-Small Cell Lung Cancer Cell Killing via Preferential Stimulation of Necroptosis In Vitro and In Vivo.

PubMed

Wang, Huan-Huan; Wu, Zhi-Qiang; Qian, Dong; Zaorsky, Nicholas G; Qiu, Ming-Han; Cheng, Jing-Jing; Jiang, Chao; Wang, Juan; Zeng, Xian-Liang; Liu, Chun-Lei; Tian, Li-Jun; Ying, Guo-Guang; Meng, Mao-Bin; Hao, Xi-Shan; Yuan, Zhi-Yong

2018-05-01

To investigate how necroptosis (ie, programmed necrosis) is involved in killing of non-small cell lung cancer (NSCLC) after ablative hypofractionated radiation therapy (HFRT). Deoxyribonucleic acid damage, DNA repair, and the death form of NSCLC cells were assessed after radiation therapy. The overexpression and silencing of receptor-interacting protein kinases 3 (RIP3, a key protein involved activation of necroptosis)-stable NSCLC cell lines were successfully constructed. The form of cell death, the number and area of colonies, and the regulatory proteins of necroptosis were characterized after radiation therapy in vitro. Finally, NSCLC xenografts and patient specimens were used to examine involvement of necroptosis after ablative HFRT in vivo. Radiation therapy induced expected DNA damage and repair of NSCLC cell lines, but ablative HFRT at ≥10 Gy per fraction preferentially stimulated necroptosis in NSCLC cells and xenografts with high RIP3 expression, as characterized by induction and activation of RIP3 and mixed-lineage kinase domain-like protein and release of immune-activating chemokine high-mobility group box 1. In contrast, RNA interference of RIP3 attenuated ablative HFRT-induced necroptosis and activation of its regulatory proteins. Among central early-stage NSCLC patients receiving stereotactic body radiation therapy, high expression of RIP3 was associated with improved local control and progression-free survival (all P < .05). Ablative HFRT at ≥10 Gy per fraction enhances killing of NSCLC with high RIP3 expression via preferential stimulation of necroptosis. RIP3 may serve as a useful biomarker to predict favorable response to stereotactic body radiation therapy. Copyright © 2018 Elsevier Inc. All rights reserved.

Predictive factors of esophageal stenosis associated with tumor regression in radiation therapy for locally advanced esophageal cancer.

PubMed

Atsumi, Kazushige; Shioyama, Yoshiyuki; Nakamura, Katsumasa; Nomoto, Satoshi; Ohga, Saiji; Yoshitake, Tadamasa; Nonoshita, Takeshi; Ueda, Masanobu; Hirata, Hideki; Honda, Hiroshi

2010-01-01

The purpose of this retrospective study was to clarify the predictive factors correlated with esophageal stenosis within three months after radiation therapy for locally advanced esophageal cancer. We enrolled 47 patients with advanced esophageal cancer with T2-4 and stage II-III who were treated with definitive radiation therapy and achieving complete response of primary lesion at Kyushu University Hospital between January 1998 and December 2005. Esophagography was performed for all patients before treatment and within three months after completion of the radiation therapy, the esophageal stenotic ratio was evaluated. The stenotic ratio was used to define four levels of stenosis: stenosis level 1, stenotic ratio of 0-25%; 2, 25-50%; 3,50-75%; 4,75-100%. We then estimated the correlation between the esophageal stenosis level after radiation therapy and each of numerous factors. The numbers and total percentages of patients at each stenosis level were as follows: level 1: n = 14 (30%); level 2: 8 (17%); level 3: 14 (30%); and level 4: 11 (23%). Esophageal stenosis in the case of full circumference involvement tended to be more severe and more frequent. Increases in wall thickness tended to be associated with increases in esophageal stenosis severity and frequency. The extent of involved circumference and wall thickness of tumor region were significantly correlated with esophageal stenosis associated with tumor regression in radiation therapy (p = 0.0006, p = 0.005). For predicting the possibility of esophageal stenosis with tumor regression within three months in radiation therapy, the extent of involved circumference and esophageal wall thickness of the tumor region may be useful.

Analysis of three microscopic characters for separating the wood of Pinus contorta and P. ponderosa

Treesearch

Alex C. Wiedenhoeft; Regis B. Miller; Terra J. Theim

2003-01-01

Three microscopic characters were evaluated for the identification of Pinus contorta and Pinus ponderosa. The tangential diameter of the resin canals, including the epithelium, was compared to the tangential diameter of the entire resin canal complex. The latter measurement was shown to give diagnostic results for these species. Data from the examination of ray...

Transient Electromagnetic Wave Propagation in a Plasma Waveguide

DTIC Science & Technology

2011-10-24

dielectric. The calculation of the propagation characteristics is based upon tangential continuity of the electric and magnetic field components...filament as a time-dependent resistance , we have determined the electron density, the kinetic parameters for electron attachment and recombination, and...wall conductivity simplifies the imposition of the boundary conditions. The tangential component of the electric field and the normal component of the

Effect of Nozzle Nonlinearities upon Nonlinear Stability of Liquid Propellant Rocket Motors

NASA Technical Reports Server (NTRS)

Padmanabhan, M. S.; Powell, E. A.; Zinn, B. T.

1975-01-01

A three dimensional, nonlinear nozzle admittance relation is developed by solving the wave equation describing finite amplitude oscillatory flow inside the subsonic portion of a choked, slowly convergent axisymmetric nozzle. This nonlinear nozzle admittance relation is then used as a boundary condition in the analysis of nonlinear combustion instability in a cylindrical liquid rocket combustor. In both nozzle and chamber analyses solutions are obtained using the Galerkin method with a series expansion consisting of the first tangential, second tangential, and first radial modes. Using Crocco's time lag model to describe the distributed unsteady combustion process, combustion instability calculations are presented for different values of the following parameters: (1) time lag, (2) interaction index, (3) steady-state Mach number at the nozzle entrance, and (4) chamber length-to-diameter ratio. In each case, limit cycle pressure amplitudes and waveforms are shown for both linear and nonlinear nozzle admittance conditions. These results show that when the amplitudes of the second tangential and first radial modes are considerably smaller than the amplitude of the first tangential mode the inclusion of nozzle nonlinearities has no significant effect on the limiting amplitude and pressure waveforms.

The quality assessment of radial and tangential neutron radiography beamlines of TRR

NASA Astrophysics Data System (ADS)

Choopan Dastjerdi, M. H.; Movafeghi, A.; Khalafi, H.; Kasesaz, Y.

2017-07-01

To achieve a quality neutron radiographic image in a relatively short exposure time, the neutron radiography beam must be of good quality and relatively high neutron flux. Characterization of a neutron radiography beam, such as determination of the image quality and the neutron flux, is vital for producing quality radiographic images and also provides a means to compare the quality of different neutron radiography facilities. This paper provides a characterization of the radial and tangential neutron radiography beamlines at the Tehran research reactor. This work includes determination of the facilities category according to the American Society for Testing and Materials (ASTM) standards, and also uses the gold foils to determine the neutron beam flux. The radial neutron beam is a Category I neutron radiography facility, the highest possible quality level according to the ASTM. The tangential beam is a Category IV neutron radiography facility. Gold foil activation experiments show that the measured neutron flux for radial beamline with length-to-diameter ratio (L/D) =150 is 6.1× 106 n cm-2 s-1 and for tangential beamline with (L/D)=115 is 2.4× 104 n cm-2 s-1.

Superficial Radiation Therapy for the Treatment of Nonmelanoma Skin Cancers

PubMed Central

Minni, John; Herold, David

2015-01-01

Superficial radiation therapy has become more widely available to dermatologists. With the advent of more portable machines, it has become more convenient for dermatology practices to employ in an office-based setting. The goal of this paper is to provide a deeper insight into the role of superficial radiation therapy in dermatology practice and to review the current literature surrounding its use in the treatment of both basal and squamous cell carcinomas. PMID:26705443

Tooth extraction by orthodontic force after radiation therapy: report of case

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rodu, B.; Filler, S.J.; Woodfin, G.K.

1985-12-01

This report presents a therapeutic approach to orthodontic tooth extraction in a patient at high risk for the development of osteoradionecrosis with conventional techniques. The rationale for this procedure is discussed in detail, combining principles of radiation biology, clinical radiation therapy, and biomechanics of tooth movement.

77 FR 44721 - Medicare Program; Revisions to Payment Policies Under the Physician Fee Schedule, DME Face to...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-07-30

... Classification of Diseases IMRT Intensity Modulated Radiation Therapy IOM Internet-only Manual IPCI Indirect... RIA Regulatory impact analysis RVU Relative value unit SBRT Stereotactic body radiation therapy SGR... adjust the payment rates for two common radiation oncology treatment delivery methods, intensity...

75 FR 40039 - Medicare Program; Payment Policies Under the Physician Fee Schedule and Other Revisions to Part B...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-07-13

... external defibrillator AFROC Association of Freestanding Radiation Oncology Centers AHA American Heart... Procedure Coding System HCRIS Healthcare Cost Report Information System HDRT High dose radiation therapy HH... rule with comment period IMRT Intensity-Modulated Radiation Therapy IPPE Initial preventive physical...

77 FR 45061 - Hospital Outpatient Prospective and Ambulatory Surgical Center Payment Systems and Quality...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-07-30

... radiation therapy (IORT), brachytherapy composite APC, multiple imaging composite APCs, cardiac... Outpatient Code Editor IOL Intraocular lens IOM Institute of Medicine IORT Intraoperative radiation treatment... Radiation Therapy (IORT) (APC 0412) a. Background b. CY 2013 Proposals for CPT Codes 77424, 77425, and 77469...

21 CFR 892.5770 - Powered radiation therapy patient support assembly.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Powered radiation therapy patient support assembly. 892.5770 Section 892.5770 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Therapeutic Devices § 892.5770 Powered radiation...

Dactinomycin

MedlinePlus

... in combination with other medications, surgery, and/or radiation therapy to treat Wilms' tumor (a type of ... you have previously received or are currently receiving radiation therapy.tell your doctor if you are pregnant, ...

Liposomal cytarabine in prophylaxis or curative treatment of central nervous system involvement in Burkitt leukemia/lymphoma.

PubMed

Segot, Amandine; Raffoux, Emmanuel; Lengline, Etienne; Thieblemont, Catherine; Dombret, Hervé; Boissel, Nicolas; Cluzeau, Thomas

2015-11-01

In recent years, the outcome of Burkitt leukemia/lymphoma (BL) has improved significantly. Central nervous system (CNS) involvement continues to be a poor prognostic indicator. High doses of intravenous polychemotherapy, intrathecal chemotherapy, and cranio-spinal radiation therapy are used by numerous groups. Majority of patients are cured after this strategy. The next challenge is to decrease toxicities of treatment, including long-term toxicities secondary to cranio-spinal radiation therapy observed in these cured patients. Liposomal cytarabine could be a good alternative to cranio-spinal radiation therapy as already reported in acute lymphoblastic leukemia. We report here eleven patients treated in our center for BL, with liposomal cytarabine instead of cranio-spinal radiation therapy as prophylactic or curative treatment for CNS involvement. Treatment was safe with no short-term grade >3 adverse events. Moreover, no long-term side effects and no impact on outcome were observed. We conclude that LC could be a good option to decrease short/long-term side effects of cranio-spinal radiation therapy in BL and could be evaluated in a future clinical trial.

Clinical Advances of Hypoxia-Activated Prodrugs in Combination With Radiation Therapy.

PubMed

Mistry, Ishna N; Thomas, Matthew; Calder, Ewen D D; Conway, Stuart J; Hammond, Ester M

2017-08-01

With the increasing incidence of cancer worldwide, the need for specific, effective therapies is ever more urgent. One example of targeted cancer therapeutics is hypoxia-activated prodrugs (HAPs), also known as bioreductive prodrugs. These prodrugs are inactive in cells with normal oxygen levels but in hypoxic cells (with low oxygen levels) undergo chemical reduction to the active compound. Hypoxia is a common feature of solid tumors and is associated with a more aggressive phenotype and resistance to all modes of therapy. Therefore, the combination of radiation therapy and bioreductive drugs presents an attractive opportunity for synergistic effects, because the HAP targets the radiation-resistant hypoxic cells. Hypoxia-activated prodrugs have typically been precursors of DNA-damaging agents, but a new generation of molecularly targeted HAPs is emerging. By targeting proteins associated with tumorigenesis and survival, these compounds may result in greater selectivity over healthy tissue. We review the clinical progress of HAPs as adjuncts to radiation therapy and conclude that the use of HAPs alongside radiation is vastly underexplored at the clinical level. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Radiation therapy for primary breast lymphoma in male gynecomastia: a rare case report and review of the literature.

PubMed

Ishibashi, Naoya; Hata, Masaharu; Mochizuki, Takao; Ogawa, Kogi; Sugiura, Hiroaki; Takekawa, Yoshinori; Maebayashi, Toshiya; Aizawa, Takuya; Sakaguchi, Masakuni; Abe, Osamu

2016-10-01

Primary breast lymphoma is a rare type of non-Hodgkin lymphoma and usually affects women, although a few cases have been reported in men. Chemotherapy and radiation therapy, or a combination of both, are frequently administered for treatment of primary breast lymphoma, as local control by surgical resection is poor. No standard therapy has been established, and the optimal radiation dose and irradiation field for male patients are unknown. The present report describes a 75-year-old man with bilateral cirrhosis-induced gynecomastia who was diagnosed with primary breast lymphoma; specifically, diffuse large B-cell lymphoma. Because of his hepatic dysfunction, he was treated with radiation therapy alone. Radiation therapy was followed by eight cycles of rituximab monotherapy. Clinical response was good, with no signs of relapse. Clinicians may benefit from knowledge regarding effective treatment of primary breast lymphoma in male patients, which has been rarely reported owing to the low incidence of this condition. The outcome in the present case may help to establish effective treatment guidelines in similar cases.

[Remission of acquired hemophilia A following radiation therapy for esophageal cancer].

PubMed

Yanagisawa, Kunio; Ogawa, Yoshiyuki; Mitsui, Takeki; Noguchi, Hiroyuki; Shimizu, Hiroaki; Ishizaki, Takuma; Handa, Hiroshi; Ieko, Masahiro; Ichinose, Akitada; Nojima, Yoshihisa

2016-04-01

Although acquired hemophilia A (AHA) often develops in patients with neoplasms, there are few reports on the efficacy of radiation therapy during the bleeding phase of AHA in the prior literature. We herein present a case of AHA experiencing remission soon after radiation therapy for esophageal cancer. A man in his seventies, who had a history of radical nephrectomy for left renal cell carcinoma, received a diagnosis of esophageal cancer. Three months later, he noticed a right thigh hematoma, and was transferred to our hospital. Laboratory data revealed a marked reduction of coagulation factor VIII (FVIII) activity at 0.9% and the inhibitor to FVIII was detected in his serum at 21.8 BU/ml. Under a diagnosis of AHA, the patient received high-dose oral prednisolone, which failed to achieve disease remission. He then underwent radiation therapy to eradicate the underlying esophageal cancer. Despite tapering of the prednisolone dosage, FVIII inhibitor declined to undetectable levels. In this case, radiation therapy for the underlying cancer was associated with achieving complete remission of AHA.

Prostate tumor alignment and continuous, real-time adaptive radiation therapy using electromagnetic fiducials: clinical and cost-utility analyses.

PubMed

Quigley, Martin M; Mate, Timothy P; Sylvester, John E

2009-01-01

To evaluate the accuracy, utility, and cost effectiveness of a new electromagnetic patient positioning and continuous, real-time monitoring system, which uses permanently implanted resonant transponders in the target (Calypso 4D Localization System and Beacon transponders, Seattle, WA) to continuously monitor tumor location and movement during external beam radiation therapy of the prostate. This clinical trial studied 43 patients at 5 sites. All patients were implanted with 3 transponders each. In 41 patients, the system was used for initial alignment at each therapy session. Thirty-five patients had continuous monitoring during their radiation treatment. Over 1,000 alignment comparisons were made to a commercially available kV X-ray positioning system (BrainLAB ExacTrac, Munich, Germany). Using decision analysis and Markov processes, the outcomes of patients were simulated over a 5-year period and measured in terms of costs from a payer's perspective and quality-adjusted life years (QALYs). All patients had satisfactory transponder implantations for monitoring purposes. In over 75% of the treatment sessions, the correction to conventional positioning (laser and tattoos) directed by an electromagnetic patient positioning and monitoring system was greater than 5 mm. Ninety-seven percent (34/35) of the patients who underwent continuous monitoring had target motion that exceeded preset limits at some point during the course of their radiation therapy. Exceeding preset thresholds resulted in user intervention at least once during the therapy in 80% of the patients (28/35). Compared with localization using ultrasound, electronic portal imaging devices (EPID), or computed tomography (CT), localization with the electromagnetic patient positioning and monitoring system yielded superior gains in QALYs at comparable costs. Most patients positioned with conventional tattoos and lasers for prostate radiation therapy were found by use of the electromagnetic patient positioning and monitoring system to have alignment errors exceeding 5 mm. Almost all patients undergoing external beam radiation of the prostate have been shown to have target organ movement exceeding 3 mm during radiation therapy delivery. The ability of the electromagnetic technology to monitor tumor target location during the same time as radiation therapy is being delivered allows clinicians to provide real time adaptive radiation therapy for prostate cancer. This permits clinicians to intervene when the prostate moves outside the radiation isocenter, which should decrease adverse events and improve patient outcomes. Additionally, a cost-utility analysis has demonstrated that the electromagnetic patient positioning and monitoring system offers patient outcome benefits at a cost that falls well within the payer's customary willingness to pay (WTP) threshold of $50,000 per QALY.

The Effect of Reflexology on the Pain-Insomnia-Fatigue Disturbance Cluster of Breast Cancer Patients During Adjuvant Radiation Therapy.

PubMed

Tarrasch, Ricardo; Carmel-Neiderman, Narin N; Ben-Ami, Sarah; Kaufman, Bella; Pfeffer, Raphi; Ben-David, Merav; Gamus, Dorit

2018-01-01

To evaluate the effects of reflexology treatment on quality of life, sleep disturbances, and fatigue in breast cancer patients during radiation therapy. A total of 72 women with breast cancer (stages 1-3) scheduled for radiation therapy were recruited. Women were allocated upon their preference either to the group receiving reflexology treatments once a week concurrently with radiotherapy and continued for 10 weeks or to the control group (usual care). The Lee Fatigue Scale, General Sleep Disturbance Scale, and Multidimensional Quality of Life Scale Cancer were completed by each patient in both arms at the beginning of the radiation treatment, after 5 weeks, and after 10 weeks of reflexology treatment. The final analysis included 58 women. The reflexology treated group demonstrated statistically significant lower levels of fatigue after 5 weeks of radiation therapy (p < 0.001), compared to the control group. It was also detected that although the quality of life in the control group deteriorated after 5 and 10 weeks of radiation therapy (p < 0.01 and p < 0.05, respectively), it was preserved in the reflexology group, which also demonstrated a significant improvement in the quality of sleep after 10 weeks of radiation treatment (p < 0.05). Similar patterns were obtained in the assessment of the pain levels experienced by the patients. The results of the present study indicate that reflexology may have a positive effect on fatigue, quality of sleep, pain, and quality of life in breast cancer patients during radiation therapy. Reflexology prevented the decline in quality of life and significantly ameliorated the fatigue and quality of sleep of these patients. An encouraging trend was also noted in amelioration of pain levels.

How do I deal with the axilla in patients with a positive sentinel lymph node?

PubMed

Falkson, Conrad B

2011-12-01

Optimal management of the axilla in a patient with a positive sentinel node biopsy is not yet defined.These patients usually have Breast Conserving Surgery and receive adjuvant systemic therapy and whole breast radiation.Treatment options for the axilla include: no further surgery with or without radiation completion axillary nodal dissection with or without radiation Radiation options in addition to whole breast radiation include axillary and supraclavicular nodal irradiation regional nodal irradiationincludes supraclavicular and internal mammary nodes Completion axillary dissection has been standard practice in patients with positive sentinel nodes. the number of involved nodes provides prognostic information. theoretically improves local control, but may be obviated by systemic chemotherapy. but avoidance of dissection may not adversely affect locoregional control or survival. dissection has significant morbidity so safe avoidance is desirable. There is little worldwide concordance on the use of radiation: whole breast radiation (commonly used after breast conserving surgery) may radiate the lower axilla supraclavicular radiation is most commonly recommended for patients with four or more nodes but may confer a survival benefit on patients with lower risk disease. adding nodal irradiation reduces local recurrence with only modest toxicity. Adjuvant systemic therapy provides a survival benefit for patients with nodal disease. Most will receive cytostatic chemotherapy containing an anthracycline and a taxane. Hormone therapy is appropriate for estrogen receptor positive disease. The extent to which systemic therapy controls microscopic nodal disease is unknown. Node positive patients should generally receive adjuvant chemotherapy.A small group of patients benefit from specific nodal therapy. Further studies are needed to better identify these patients.

Advanced Small Animal Conformal Radiation Therapy Device.

PubMed

Sharma, Sunil; Narayanasamy, Ganesh; Przybyla, Beata; Webber, Jessica; Boerma, Marjan; Clarkson, Richard; Moros, Eduardo G; Corry, Peter M; Griffin, Robert J

2017-02-01

We have developed a small animal conformal radiation therapy device that provides a degree of geometrical/anatomical targeting comparable to what is achievable in a commercial animal irradiator. small animal conformal radiation therapy device is capable of producing precise and accurate conformal delivery of radiation to target as well as for imaging small animals. The small animal conformal radiation therapy device uses an X-ray tube, a robotic animal position system, and a digital imager. The system is in a steel enclosure with adequate lead shielding following National Council on Radiation Protection and Measurements 49 guidelines and verified with Geiger-Mueller survey meter. The X-ray source is calibrated following AAPM TG-61 specifications and mounted at 101.6 cm from the floor, which is a primary barrier. The X-ray tube is mounted on a custom-made "gantry" and has a special collimating assembly system that allows field size between 0.5 mm and 20 cm at isocenter. Three-dimensional imaging can be performed to aid target localization using the same X-ray source at custom settings and an in-house reconstruction software. The small animal conformal radiation therapy device thus provides an excellent integrated system to promote translational research in radiation oncology in an academic laboratory. The purpose of this article is to review shielding and dosimetric measurement and highlight a few successful studies that have been performed to date with our system. In addition, an example of new data from an in vivo rat model of breast cancer is presented in which spatially fractionated radiation alone and in combination with thermal ablation was applied and the therapeutic benefit examined.

Students' expectations of clinical teachers.

PubMed

Daniels, M; DeVos, D

1996-01-01

Clinical instructors play an essential role in the education of all health care students, including radiation therapy students. However, a review of the literature shows that no studies have examined radiation therapy students' expectations of their clinical instructors. To assess those expectations, a national survey was conducted of 282 radiation therapy students enrolled in 61 programs in 28 states. Survey results then were analyzed to generate a list of the students' expectations of clinical instructors and to look at possible significant relationships between the various groups surveyed. Survey results showed that the most common expectation among first-, second- and third-year radiation therapy students was that their clinical instructors "take time, both in explaining procedures and answering questions." Among fourth-year students, the most commonly cited expectation for clinical instructors was that they "model professionalism."

Carcinoma of penis. Review of cases treated by surgery and radiation therapy 1960-1977

DOE Office of Scientific and Technical Information (OSTI.GOV)

Krieg, R.M.; Luk, K.H.

1981-08-01

Cases of squamous cell carcinoma of the penis treated by surgery and radiation therapy at Moffitt Hospital, University of California, and Mount Zion Hospital and Medical Center are reviewed. Only cases followed for more than three years or with autopsy findings are presented. For the primary lesion, over-all surgical control rate locally was 15/17 or 88 per cent. Over-all control rate with radiation therapy alone was 9/12 (75 per cent), and with surgical salvage 11/12 (92 per cent). Radiation therapy appears to be the treatment of choice for early stage lesions, reserving surgery for salvage. Prophylactic ilioinguinal lymph node dissectionmore » for N0 lesions is not warranted. The role of chemotherapy needs further investigation.« less

Whole-brain hippocampal sparing radiation therapy: Volume-modulated arc therapy vs intensity-modulated radiation therapy case study.

PubMed

Lee, Katrina; Lenards, Nishele; Holson, Janice

2016-01-01

The hippocampus is responsible for memory and cognitive function. An ongoing phase II clinical trial suggests that sparing dose to the hippocampus during whole-brain radiation therapy can help preserve a patient׳s neurocognitive function. Progressive research and advancements in treatment techniques have made treatment planning more sophisticated but beneficial for patients undergoing treatment. The aim of this study is to evaluate and compare hippocampal sparing whole-brain (HS-WB) radiation therapy treatment planning techniques using volume-modulated arc therapy (VMAT) and intensity-modulated radiation therapy (IMRT). We randomly selected 3 patients to compare different treatment techniques that could be used for reducing dose to the hippocampal region. We created 2 treatment plans, a VMAT and an IMRT, from each patient׳s data set and planned on the Eclipse 11.0 treatment planning system (TPS). A total of 6 plans (3 IMRT and 3 VMAT) were created and evaluated for this case study. The physician contoured the hippocampus as per the Radiation Therapy Oncology Group (RTOG) 0933 protocol atlas. The organs at risk (OR) were contoured and evaluated for the plan comparison, which included the spinal cord, optic chiasm, the right and left eyes, lenses, and optic nerves. Both treatment plans produced adequate coverage on the planning target volume (PTV) while significantly reducing dose to the hippocampal region. The VMAT treatment plans produced a more homogenous dose distribution throughout the PTV while decreasing the maximum point dose to the target. However, both treatment techniques demonstrated hippocampal sparing when irradiating the whole brain. Copyright © 2016 American Association of Medical Dosimetrists. Published by Elsevier Inc. All rights reserved.

Treatment of Head and Neck Paragangliomas With External Beam Radiation Therapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dupin, Charles, E-mail: c.dupin@bordeaux.unicancer.fr; Lang, Philippe; Dessard-Diana, Bernadette

2014-06-01

Purpose: To retrospectively assess the outcomes of radiation therapy in patients with head and neck paragangliomas. Methods and Materials: From 1990 to 2009, 66 patients with 81 head and neck paragangliomas were treated by conventional external beam radiation therapy in 25 fractions at a median dose of 45 Gy (range, 41.4-68 Gy). One case was malignant. The median gross target volume and planning target volume were 30 cm{sup 3} (range, 0.9-243 cm{sup 3}) and 116 cm{sup 3} (range, 24-731 cm{sup 3}), respectively. Median age was 57.4 years (range, 15-84 years). Eleven patients had multicentric lesions, and 8 had family histories ofmore » paraganglioma. Paragangliomas were located in the temporal bone, the carotid body, and the glomus vagal in 51, 18, and 10 patients, respectively. Forty-six patients had exclusive radiation therapy, and 20 had salvage radiation therapy. The median follow-up was 4.1 years (range, 0.1-21.2 years). Results: One patient had a recurrence of temporal bone paraganglioma 8 years after treatment. The actuarial local control rates were 100% at 5 years and 98.7% at 10 years. Patients with multifocal tumors and family histories were significantly younger (42 years vs 58 years [P=.002] and 37 years vs 58 years [P=.0003], respectively). The association between family predisposition and multifocality was significant (P<.001). Two patients had cause-specific death within the 6 months after irradiation. During radiation therapy, 9 patients required hospitalization for weight loss, nausea, mucositis, or ophthalmic zoster. Two late vascular complications occurred (middle cerebral artery and carotid stenosis), and 2 late radiation-related meningiomas appeared 15 and 18 years after treatment. Conclusion: Conventional external beam radiation therapy is an effective and safe treatment option that achieves excellent local control; it should be considered as a first-line treatment of choice for head and neck paragangliomas.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Specht, Lena, E-mail: lena.specht@regionh.dk; Dabaja, Bouthaina; Illidge, Tim

Primary cutaneous lymphomas are a heterogeneous group of diseases. They often remain localized, and they generally have a more indolent course and a better prognosis than lymphomas in other locations. They are highly radiosensitive, and radiation therapy is an important part of the treatment, either as the sole treatment or as part of a multimodality approach. Radiation therapy of primary cutaneous lymphomas requires the use of special techniques that form the focus of these guidelines. The International Lymphoma Radiation Oncology Group has developed these guidelines after multinational meetings and analysis of available evidence. The guidelines represent an agreed consensus viewmore » of the International Lymphoma Radiation Oncology Group steering committee on the use of radiation therapy in primary cutaneous lymphomas in the modern era.« less

[Combined palliative hypofractionated radiation and carboplatin chemotherapy of intranasal tumours in dogs].

PubMed

Schwietzer, A; Kessler, M; Kandel-Tschiederer, B

2012-10-17

Combination therapy of intranasal tumours in dogs with palliative 60 cobalt radiation and carboplatin chemotherapy. Twenty-five dogs with intranasal tumours were treated in the Hofheim Veterinary Hospital (Germany) from 2004 to 2006 with a total radiation dose of 24Gy (3 fractions of 8 Gy on days 0, 7 and 21) and five doses of Carboplatin (270-300 mg/m² BSA i.v. every 21-28 days). In 88% patients, clinical symptoms subsided partially or completely resulting in improvement in quality of life. Computed tomography revealed partial (5/25) or complete (5/25) tumour remissions. Chemotherapy was well tolerated. Radiation therapy caused no or minimal side effects except for 3 dogs (12%), which experienced serious ocular side effects resulting in loss of vision of the affected eye and one dog with epileptic seizures. Survival times ranged from 10-639 days with a median of 156 days. There was no statistically significant correlation between the parameters breed, age, sex, brain invasion or tumour stage and survival time or progression free interval. Survival time and progression free interval were significantly correlated with the degree of tumour remission. It can be concluded from this study that palliative radiation therapy combined with chemotherapy results in excellent palliation of clinical symptoms and acceptable survival times. There was no advantage of combined therapy (radiation with carboplatin) when compared to literature data on results of radiation therapy alone.

Proton therapy in clinical practice

PubMed Central

Liu, Hui; Chang, Joe Y.

2011-01-01

Radiation dose escalation and acceleration improves local control but also increases toxicity. Proton radiation is an emerging therapy for localized cancers that is being sought with increasing frequency by patients. Compared with photon therapy, proton therapy spares more critical structures due to its unique physics. The physical properties of a proton beam make it ideal for clinical applications. By modulating the Bragg peak of protons in energy and time, a conformal radiation dose with or without intensity modulation can be delivered to the target while sparing the surrounding normal tissues. Thus, proton therapy is ideal when organ preservation is a priority. However, protons are more sensitive to organ motion and anatomy changes compared with photons. In this article, we review practical issues of proton therapy, describe its image-guided treatment planning and delivery, discuss clinical outcome for cancer patients, and suggest challenges and the future development of proton therapy. PMID:21527064

Hypofractionated Radiation Therapy (66 Gy in 22 Fractions at 3 Gy per Fraction) for Favorable-Risk Prostate Cancer: Long-term Outcomes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Patel, Nita; Faria, Sergio, E-mail: sergio.faria@muhc.mcgill.ca; Cury, Fabio

2013-07-01

Purpose: To report long-term outcomes of low- and intermediate-risk prostate cancer patients treated with high-dose hypofractionated radiation therapy (HypoRT). Methods and Materials: Patients with low- and intermediate-risk prostate cancer were treated using 3-dimensional conformal radiation therapy to a dose of 66 Gy in 22 daily fractions of 3 Gy without hormonal therapy. A uniform 7-mm margin was created around the prostate for the planning target volume, and treatment was prescribed to the isocenter. Treatment was delivered using daily ultrasound image-guided radiation therapy. Common Terminology Criteria for Adverse Events, version 3.0, was used to prospectively score toxicity. Biochemical failure was definedmore » as the nadir prostate-specific antigen level plus 2 ng/mL. Results: A total of 129 patients were treated between November 2002 and December 2005. With a median follow-up of 90 months, the 5- and 8-year actuarial biochemical control rates were 97% and 92%, respectively. The 5- and 8-year actuarial overall survival rates were 92% and 88%, respectively. Only 1 patient died from prostate cancer at 92 months after treatment, giving an 8-year actuarial cancer-specific survival of 98%. Radiation therapy was well tolerated, with 57% of patients not experiencing any acute gastrointestinal (GI) or genitourinary (GU) toxicity. For late toxicity, the worst grade ≥2 rate for GI and GU toxicity was 27% and 33%, respectively. There was no grade >3 toxicity. At last follow-up, the rate of grade ≥2 for both GI and GU toxicity was only 1.5%. Conclusions: Hypofractionation with 66 Gy in 22 fractions prescribed to the isocenter using 3-dimensional conformal radiation therapy produces excellent biochemical control rates, with moderate toxicity. However, this regimen cannot be extrapolated to the intensity modulated radiation therapy technique.« less

Use of 4MAT Learning Theory to Promote Better Skin Care During Radiation Therapy: An Evidence-Based Quality Improvement Project.

PubMed

Bauer, Carole; Magnan, Morris; Laszewski, Pamela

Radiation therapy is a key treatment modality for cancer patients, but it is associated with adverse side effects such as radiation dermatitis. To mitigate the adverse effects of radiation on the skin, patients must participate in skin-related self-care. However, even with self-care instruction, adherence can be poor. This quality improvement project used best available evidence for skin care in patients undergoing radiation therapy and a theoretical framework, 4MATing, to provide a structured approach to patient education designed to enhance adherence to skin care recommendations. Implementation of this approach resulted in increased adherence to a topical skin care protocol in our facility. Patients were highly satisfied with their education. While there was a 4-day delay in the onset of radiation dermatitis, this difference was not statistically significant.

The impact of toceranib, piroxicam and thalidomide with or without hypofractionated radiation therapy on clinical outcome in dogs with inflammatory mammary carcinoma.

PubMed

Rossi, F; Sabattini, S; Vascellari, M; Marconato, L

2018-05-27

In dogs, inflammatory mammary carcinoma is a clinicopathological entity characterized by rapid progression and aggressive behavior from onset of disease. Reported median survival time is short, with no effective treatment options. The aims of this prospective, noncontrolled clinical trial were to investigate outcome variables and safety profile of toceranib, thalidomide and piroxicam with or without hypofractionated radiation therapy in dogs with measurable histologically confirmed inflammatory mammary carcinoma that underwent a complete staging. Eighteen dogs were enrolled: 14 received medical treatment, and 4 were treated with hypofractionated radiation therapy and medical therapy. Overall, median time to progression was 34 days and median survival time was 109 days. In dogs treated with medical therapy, overall response rate was 21%, and clinical benefit rate (CBR) was 64%; median time to progression was 28 days and median survival time was 59 days. In dogs receiving medical therapy and undergoing radiation therapy, overall response rate and clinical benefit rate were 100%, with significantly longer time to progression (156 days) and survival time (180 days). Overall, treatment was well tolerated, with mild gastrointestinal and dermatological adverse events. Although the optimal treatment to this disease remains uncertain, the current approach consisting of systemic anti-angiogenic drugs with or without hypofractionated radiation therapy, provided clinical benefit in a significant proportion of dogs and should, therefore, be further explored. © 2018 John Wiley & Sons Ltd.

Comparison of risk of radiogenic second cancer following photon and proton craniospinal irradiation for a pediatric medulloblastoma patient

NASA Astrophysics Data System (ADS)

Zhang, Rui; Howell, Rebecca M.; Giebeler, Annelise; Taddei, Phillip J.; Mahajan, Anita; Newhauser, Wayne D.

2013-02-01

Pediatric patients who received radiation therapy are at risk of developing side effects such as radiogenic second cancer. We compared proton and photon therapies in terms of the predicted risk of second cancers for a 4 year old medulloblastoma patient receiving craniospinal irradiation (CSI). Two CSI treatment plans with 23.4 Gy or Gy (RBE) prescribed dose were computed: a three-field 6 MV photon therapy plan and a four-field proton therapy plan. The primary doses for both plans were determined using a commercial treatment planning system. Stray radiation doses for proton therapy were determined from Monte Carlo simulations, and stray radiation doses for photon therapy were determined from measured data. Dose-risk models based on the Biological Effects of Ionization Radiation VII report were used to estimate the risk of second cancer in eight tissues/organs. Baseline predictions of the relative risk for each organ were always less for proton CSI than for photon CSI at all attained ages. The total lifetime attributable risk of the incidence of second cancer considered after proton CSI was much lower than that after photon CSI, and the ratio of lifetime risk was 0.18. Uncertainty analysis revealed that the qualitative findings of this study were insensitive to any plausible changes of dose-risk models and mean radiation weighting factor for neutrons. Proton therapy confers lower predicted risk of second cancer than photon therapy for the pediatric medulloblastoma patient.

Lymphangiosarcoma of the edematous thigh after radiation therapy for carcinoma of the vulva

DOE Office of Scientific and Technical Information (OSTI.GOV)

Huey, G.R.; Stehman, F.B.; Roth, L.M.

1985-03-01

A 66-year-old patient was treated with external radiation therapy for an advanced carcinoma of the vulva. Seven years later, a lymphangiosarcoma developed in her edematous lower extremity. Lymphangiosarcomas have been reported to occur in postmastectomy patients; however, this is only the third case in a patient with a gynecologic primary malignancy. In anticipation of possible increased use of radiation therapy in vulvar carcinoma, gynecologists should be aware of this rare, highly aggressive neoplasm.

Trans-oral miniature X-ray radiation delivery system with endoscopic optical feedback.

PubMed

Boese, Axel; Johnson, Fredrick; Ebert, Till; Mahmoud-Pashazadeh, Ali; Arens, Christoph; Friebe, Michael

2017-11-01

Surgery, chemo- and/or external radiation therapy are the standard therapy options for the treatment of laryngeal cancer. Trans-oral access for the surgery reduces traumata and hospitalization time. A new trend in treatment is organ-preserving surgery. To avoid regrowth of cancer, this type of surgery can be combined with radiation therapy. Since external radiation includes healthy tissue surrounding the cancerous zone, a local and direct intraoral radiation delivery would be beneficial. A general concept for a trans-oral radiation system was designed, based on clinical need identification with a medical user. A miniaturized X-ray tube was used as the radiation source for the intraoperative radiation delivery. To reduce dose distribution on healthy areas, the X-ray source was collimated by a newly designed adjustable shielding system as part of the housing. For direct optical visualization of the radiation zone, a miniature flexible endoscope was integrated into the system. The endoscopic light cone and the field of view were aligned with the zone of the collimated radiation. The intraoperative radiation system was mounted on a semi-automatic medical holder that was combined with a frontal actuator for rotational and translational movement using piezoelectric motors to provide precise placement. The entire technical set-up was tested in a simulated environment. The shielding of the X-ray source was verified by performing conventional detector-based dose measurements. The delivered dose was estimated by an ionization chamber. The adjustment of the radiation zone was performed by a manual controlling mechanism integrated into the hand piece of the device. An endoscopic fibre was also added to offer visualization and illumination of the radiation zone. The combination of the radiation system with the semi-automatic holder and actuator offered precise and stable positioning of the device in range of micrometres and will allow for future combination with a radiation planning system. The presented system was designed for radiation therapy of the oral cavity and the larynx. This first set-up tried to cover all clinical aspects that are necessary for a later use in surgery. The miniaturized X-ray tube offers the size and the power for intraoperative radiation therapy. The adjustable shielding system in combination with the holder and actuator provides a precise placement. The visualization of radiation zone allows a targeting and observation of the radiation zone.

Metformin: A Novel Biological Modifier of Tumor Response to Radiation Therapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Koritzinsky, Marianne, E-mail: mkoritzi@uhnresearch.ca

2015-10-01

Over the last decade, evidence has emerged to support a role for the antidiabetic drug metformin in the prevention and treatment of cancer. In particular, recent studies demonstrate that metformin enhances tumor response to radiation in experimental models, and retrospective analyses have shown that diabetic cancer patients treated with radiation therapy have improved outcomes if they take metformin to control their diabetes. Metformin may therefore be of utility for nondiabetic cancer patients treated with radiation therapy. The purpose of this review is to examine the data pertaining to an interaction between metformin and radiation, highlighting the essential steps needed tomore » advance our current knowledge. There is also a focus on key biomarkers that should accompany prospective clinical trials in which metformin is being examined as a modifying agent with radiation therapy. Existing evidence supports that the mechanism underlying the ability of metformin to enhance radiation response is multifaceted, and includes direct radiosensitization as well as a reduction in tumor stem cell fraction, proliferation, and tumor hypoxia. Interestingly, metformin may enhance radiation response specifically in certain genetic backgrounds, such as in cells with loss of the tumor suppressors p53 and LKB1, giving rise to a therapeutic ratio and potential predictive biomarkers.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chang, S; Zhang, J; Hadsell, M

Purpose: Microbeam radiation therapy and GRID therapy are different forms of Spatially-Fractioned Radiation Therapy (SFRT) that is fundamentally different from the conventional seamless and temporally fractionated radiation therapy. SFRT is characterized by a ultra-high dose (10s –100s Gy) dose single treatment with drastic inhomogeneity pattern of given spatial frequencies. Preclinical and limited clinical studies have shown that the SFRT treatments may offer significant improvements in reducing treatment toxicity, especially for those patients who have not benefited from the state-of-the-art radiation therapy approaches. This preliminary study aims to elucidate the underlying working mechanisms of SFRT, which currently remains poorly understood. Methods:more » A genetically engineered 4T1 murine mammary carcinoma cell line and nude mice skin fold window chamber were used. A nanotechnology-based 160kV x-ray irradiator delivered 50Gy (entrance dose) single treatments of microbeam or seamless radiation. Animals were in 3 groups: mock, seamless radiation, and 300μm microbeam radiation. The windows were imaged using a hyperspectral system to capture total hemoglobin/saturation, GFP fluorescence emission, RFP fluorescence emission, and vessel density at 9 time points up to 7 days post radiation. Results: We found unique physiologic changes in different tumor/normal tissue regions and differential effects between seamless and microbeam treatments. They include 1) compared to microbeam and mock radiation seamless radiation damaged more microvasculature in tumor-surrounding normal tissue, 2) a pronounced angiogenic effect was observed with vascular proliferation in the microbeam irradiated portion of the tumor days post treatment (no such effect observed in seamless and mock groups), and 3) a notable change in tumor vascular orientation was observed where vessels initially oriented parallel to the beam length were replaced by vessels running perpendicular to the irradiation portion of the tumor. Conclusion: Our preliminary study indicated that microbeam radiation modified tumor microenvironment in ways significantly different than of the conventional seamless radiation.« less

Supply and Demand for Radiation Oncology in the United States: Updated Projections for 2015 to 2025

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pan, Hubert Y.; Haffty, Bruce G.; Falit, Benjamin P.

Purpose: Prior studies have forecasted demand for radiation therapy to grow 10 times faster than the supply between 2010 and 2020. We updated these projections for 2015 to 2025 to determine whether this imbalance persists and to assess the accuracy of prior projections. Methods and Materials: The demand for radiation therapy between 2015 and 2025 was estimated by combining current radiation utilization rates determined by the Surveillance, Epidemiology, and End Results data with population projections provided by the US Census Bureau. The supply of radiation oncologists was forecast by using workforce demographics and full-time equivalent (FTE) status provided by themore » American Society for Radiation Oncology (ASTRO), current resident class sizes, and expected survival per life tables from the US Centers for Disease Control. Results: Between 2015 and 2025, the annual total number of patients receiving radiation therapy during their initial treatment course is expected to increase by 19%, from 490,000 to 580,000. Assuming a graduating resident class size of 200, the number of FTE physicians is expected to increase by 27%, from 3903 to 4965. In comparison with prior projections, the new projected demand for radiation therapy in 2020 dropped by 24,000 cases (a 4% relative decline). This decrease is attributable to an overall reduction in the use of radiation to treat cancer, from 28% of all newly diagnosed cancers in the prior projections down to 26% for the new projections. By contrast, the new projected supply of radiation oncologists in 2020 increased by 275 FTEs in comparison with the prior projection for 2020 (a 7% relative increase), attributable to rising residency class sizes. Conclusion: The supply of radiation oncologists is expected to grow more quickly than the demand for radiation therapy from 2015 to 2025. Further research is needed to determine whether this is an appropriate correction or will result in excess capacity.« less

Radiation Therapy Induces Macrophages to Suppress T-Cell Responses Against Pancreatic Tumors in Mice.

PubMed

Seifert, Lena; Werba, Gregor; Tiwari, Shaun; Giao Ly, Nancy Ngoc; Nguy, Susanna; Alothman, Sara; Alqunaibit, Dalia; Avanzi, Antonina; Daley, Donnele; Barilla, Rocky; Tippens, Daniel; Torres-Hernandez, Alejandro; Hundeyin, Mautin; Mani, Vishnu R; Hajdu, Cristina; Pellicciotta, Ilenia; Oh, Philmo; Du, Kevin; Miller, George

2016-06-01

The role of radiation therapy in the treatment of patients with pancreatic ductal adenocarcinoma (PDA) is controversial. Randomized controlled trials investigating the efficacy of radiation therapy in patients with locally advanced unresectable PDA have reported mixed results, with effects ranging from modest benefit to worse outcomes compared with control therapies. We investigated whether radiation causes inflammatory cells to acquire an immune-suppressive phenotype that limits the therapeutic effects of radiation on invasive PDAs and accelerates progression of preinvasive foci. We investigated the effects of radiation therapy in p48(Cre);LSL-Kras(G12D) (KC) and p48(Cre);LSLKras(G12D);LSL-Trp53(R172H) (KPC) mice, as well as in C57BL/6 mice with orthotopic tumors grown from FC1242 cells derived from KPC mice. Some mice were given neutralizing antibodies against macrophage colony-stimulating factor 1 (CSF1 or MCSF) or F4/80. Pancreata were exposed to doses of radiation ranging from 2 to 12 Gy and analyzed by flow cytometry. Pancreata of KC mice exposed to radiation had a higher frequency of advanced pancreatic intraepithelial lesions and more foci of invasive cancer than pancreata of unexposed mice (controls); radiation reduced survival time by more than 6 months. A greater proportion of macrophages from radiation treated invasive and preinvasive pancreatic tumors had an immune-suppressive, M2-like phenotype compared with control mice. Pancreata from mice exposed to radiation had fewer CD8(+) T cells than controls, and greater numbers of CD4(+) T cells of T-helper 2 and T-regulatory cell phenotypes. Adoptive transfer of T cells from irradiated PDA to tumors of control mice accelerated tumor growth. Radiation induced production of MCSF by PDA cells. A neutralizing antibody against MCSF prevented radiation from altering the phenotype of macrophages in tumors, increasing the anti-tumor T-cell response and slowing tumor growth. Radiation treatment causes macrophages murine PDA to acquire an immune-suppressive phenotype and disabled T-cell-mediated anti-tumor responses. MCSF blockade negates this effect, allowing radiation to have increased efficacy in slowing tumor growth. Copyright © 2016 AGA Institute. Published by Elsevier Inc. All rights reserved.

Review of Real-Time 3-Dimensional Image Guided Radiation Therapy on Standard-Equipped Cancer Radiation Therapy Systems: Are We at the Tipping Point for the Era of Real-Time Radiation Therapy?

PubMed

Keall, Paul J; Nguyen, Doan Trang; O'Brien, Ricky; Zhang, Pengpeng; Happersett, Laura; Bertholet, Jenny; Poulsen, Per R

2018-04-14

To review real-time 3-dimensional (3D) image guided radiation therapy (IGRT) on standard-equipped cancer radiation therapy systems, focusing on clinically implemented solutions. Three groups in 3 continents have clinically implemented novel real-time 3D IGRT solutions on standard-equipped linear accelerators. These technologies encompass kilovoltage, combined megavoltage-kilovoltage, and combined kilovoltage-optical imaging. The cancer sites treated span pelvic and abdominal tumors for which respiratory motion is present. For each method the 3D-measured motion during treatment is reported. After treatment, dose reconstruction was used to assess the treatment quality in the presence of motion with and without real-time 3D IGRT. The geometric accuracy was quantified through phantom experiments. A literature search was conducted to identify additional real-time 3D IGRT methods that could be clinically implemented in the near future. The real-time 3D IGRT methods were successfully clinically implemented and have been used to treat more than 200 patients. Systematic target position shifts were observed using all 3 methods. Dose reconstruction demonstrated that the delivered dose is closer to the planned dose with real-time 3D IGRT than without real-time 3D IGRT. In addition, compromised target dose coverage and variable normal tissue doses were found without real-time 3D IGRT. The geometric accuracy results with real-time 3D IGRT had a mean error of <0.5 mm and a standard deviation of <1.1 mm. Numerous additional articles exist that describe real-time 3D IGRT methods using standard-equipped radiation therapy systems that could also be clinically implemented. Multiple clinical implementations of real-time 3D IGRT on standard-equipped cancer radiation therapy systems have been demonstrated. Many more approaches that could be implemented were identified. These solutions provide a pathway for the broader adoption of methods to make radiation therapy more accurate, impacting tumor and normal tissue dose, margins, and ultimately patient outcomes. Copyright © 2018 Elsevier Inc. All rights reserved.

Radiation to the head, neck, and upper thorax of the young and thyroid neoplasia

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schreiner, R.L.

1976-03-01

It is now generally accepted that an association exists between external radiation administered to the head, neck and upper thorax of infants, children and adolescents and the subsequent development of neoplastic changes in the thyroid gland. Until recent years external radiation was frequently administered to shrink an enlarged thymus, or for the treatment of tonsillitis, adenoiditis, hearing loss, hemangioma, acne, tinea capitis and other conditions. During the course of these treatments, the thyroid gland was exposed to scattered radiation. It is stressed that the use of external radiation therapy was then accepted practice and its value was attested by many.more » The likelihood of adverse effects was not initially apparent, primarily because of the long periods of time between the administration of the therapy and the recognition of changes in the thyroid. The availability and effectiveness of other therapeutic measures and the growing concern about the delayed effects of radiation therapy when administered to the young for relatively benign conditions has, in recent years, largely eliminated use of this form of therapy, except in a few unusual conditions.« less

Initial boundary-value problem for the spherically symmetric Einstein equations with fluids with tangential pressure.

PubMed

Brito, Irene; Mena, Filipe C

2017-08-01

We prove that, for a given spherically symmetric fluid distribution with tangential pressure on an initial space-like hypersurface with a time-like boundary, there exists a unique, local in time solution to the Einstein equations in a neighbourhood of the boundary. As an application, we consider a particular elastic fluid interior matched to a vacuum exterior.

Apparent Viscosity of Active Nematics in Poiseuille Flow

NASA Astrophysics Data System (ADS)

Cui, Zhenlu; Su, Jianbing; Zeng, Xiaoming

2015-09-01

A Leslie-Erickson continuum hydrodynamic for flowing active nematics has been used to characterize active particle systems such as bacterial suspensions. The behavior of such a system under a plane pressure-driven Poiseuille flow is analyzed. When plate anchoring is tangential and normal, we find the apparent viscosity formula indicating a significant difference between tangential anchoring and normal anchoring conditions for both active rodlike and discoid nematics.

Forbidden tangential orbit transfers between intersecting Keplerian orbits

NASA Technical Reports Server (NTRS)

Burns, Rowland E.

1990-01-01

The classical problem of tangential impulse transfer between coplanar Keplerian orbits is addressed. A completely analytic solution which does not rely on sequential calculation is obtained and this solution is used to demonstrate that certain initially chosen angles can produce singularities in the parameters of the transfer orbit. A necessary and sufficient condition for such singularities is that the initial and final orbits intersect.

Algebra and topology for applications to physics

NASA Technical Reports Server (NTRS)

Rozhkov, S. S.

1987-01-01

The principal concepts of algebra and topology are examined with emphasis on applications to physics. In particular, attention is given to sets and mapping; topological spaces and continuous mapping; manifolds; and topological groups and Lie groups. The discussion also covers the tangential spaces of the differential manifolds, including Lie algebras, vector fields, and differential forms, properties of differential forms, mapping of tangential spaces, and integration of differential forms.

Does the presence of an implant including expander with internal port alter radiation dose? An ex vivo model

PubMed Central

Strang, Barbara; Murphy, Kyla; Seal, Shane; Cin, Arianna Dal

2013-01-01

BACKGROUND: There is a lack of literature examining the dosimetric implications of irradiating breast implants and expanders with internal ports inserted at the time of mastectomy. OBJECTIVE: To determine whether the presence of breast expanders with port in saline or silicone implants affect the dose uniformity across the breast when irradiated with various photon and electron energies. METHODS: One tissue-equivalent torso phantom with overlying tissue expanders in saline or silicone implants were irradiated using tangential fields with 6 MV and 18 MV photons and 9 MeV and 12 MeV electrons. All dose measurements were performed using thermoluminescent dosimeters (TLDs). The TLDs were arranged around the port and the perimeters of either the expander, or saline or silicone implant. Comparisons of measured radiation doses, and between the expected and measured doses of radiation from the TLDs on each prosthesis, were performed. Data were analyzed using two-tailed t tests. RESULTS: There were no differences in TLD measurements between the expander and the saline implant for all energy modalities, and for the expected versus actual measurements for the saline implant. Higher than anticipated measurements were recorded for a significant number of TLD positions around the silicone implants. CONCLUSIONS: Radiation doses around saline implants or expanders with internal port were unaltered, whereas dose recordings for silicone implants were higher than predicted in the present laboratory/ex vivo study. PMID:24431935

Ewing's sarcoma of bone tumor cells produces MCSF that stimulates monocyte proliferation in a novel mouse model of Ewing's sarcoma of bone.

PubMed

Margulies, B S; DeBoyace, S D; Damron, T A; Allen, M J

2015-10-01

Ewing's sarcoma of bone is a primary childhood malignancy of bone that is treated with X-radiation therapy in combination with surgical excision and chemotherapy. To better study Ewing's sarcoma of bone we developed a novel model of primary Ewing's sarcoma of bone and then treated animals with X-radiation therapy. We identified that uncontrolled tumor resulted in lytic bone destruction while X-radiation therapy decreased lytic bone destruction and increased limb-length asymmetry, a common, crippling complication of X-radiation therapy. Osteoclasts were indentified adjacent to the tumor, however, we were unable to detect RANK-ligand in the Ewing's tumor cells in vitro, which lead us to investigate alternate mechanisms for osteoclast formation. Ewing's sarcoma tumor cells and archival Ewing's sarcoma of bone tumor biopsy samples were shown to express MCSF, which could promote osteoclast formation. Increased monocyte numbers were detected in peripheral blood and spleen in animals with untreated Ewing's sarcoma tumor while monocyte number in animals treated with x-radiation had normal numbers of monocytes. Our data suggest that our Ewing's sarcoma of bone model will be useful in the study Ewing's sarcoma tumor progression in parallel with the effects of chemotherapy and X-radiation therapy. Copyright © 2015 Elsevier Inc. All rights reserved.

Ewing's Sarcoma of Bone Tumor Cells Produce MCSF that Stimulates Monocyte Proliferation in a Novel Mouse Model of Ewing's Sarcoma of Bone

PubMed Central

Margulies, BS; DeBoyace, SD; Damron, TA; Allen, MJ

2015-01-01

Ewing's sarcoma of bone is a primary childhood malignancy of bone that is treated with X-radiation therapy in combination with surgical excision and chemotherapy. To better study Ewing's sarcoma of bone we developed a novel model of primary Ewing's sarcoma of bone and then treated animals with X-radiation therapy. We identified that uncontrolled tumor resulted in lytic bone destruction while X-radiation therapy decreased lytic bone destruction and increased limb-length asymmetry, a common, crippling complication of X-radiation therapy. Osteoclasts were indentified adjacent to the tumor, however, we were unable to detect RANK-ligand in the Ewing's tumor cells in vitro, which lead us to investigate alternate mechanisms for osteoclast formation. Ewing's sarcoma tumor cells and archival Ewing's sarcoma of bone tumor biopsy samples were shown to express MCSF, which could promote osteoclast formation. Increased monocyte numbers were detected in peripheral blood and spleen in animals with untreated Ewing's sarcoma tumor while monocyte number in animals treated with x-radiation had normal numbers of monocytes. Our data suggest that our Ewing's sarcoma of bone model will be useful in the study Ewing's sarcoma tumor progression in parallel with the effects of chemotherapy and X-radiation therapy. PMID:26051470

Adenovirus-mediated p53 gene delivery potentiates the radiation-induced growth inhibition of experimental brain tumors.

PubMed

Badie, B; Kramar, M H; Lau, R; Boothman, D A; Economou, J S; Black, K L

1998-05-01

Patients with malignant gliomas continue to have very poor prognosis even after surgical resection, radiation and chemotherapy. Because these tumors often have alterations in the p53 tumor suppressor gene, which plays a key role in the cellular response to DNA damaging agents, we investigated the role of p53 gene therapy in conjunction with ionizing radiation in a rat brain tumor model. Exposure of cultured rat 9L gliosarcoma cells, which contain a mutant p53 gene, to a recombinant adenovirus-vector bearing the wild-type p53 gene (Adp53), induced apoptosis within 24 hours. Although ionizing radiation had no additional effect on apoptosis within this time frame, it caused G1 arrest in non-apoptotic cells after Adp53 therapy. In contrast, wild-type 9L cells demonstrated little G1 arrest after X-irradiation. When animals bearing brain tumors were irradiated after intratumoral Adp53 injections, more than 85% reduction in tumor size was noted. Moreover, the group of rats receiving both radiation and Adp53 therapy had a significant increase in survival as compared to animals receiving either therapy alone. These results support the use of p53 gene therapy as an adjunct to radiation in treatment of malignant brain tumors.

PET evaluation of late cerebral effect in advanced radiation therapy techniques for cranial base tumors.

PubMed

Alongi, Pierpaolo; Iaccarino, Leonardo; Losa, Marco; Del Vecchio, Antonella; Gerevini, Simonetta; Plebani, Valentina; Di Muzio, Nadia; Mortini, Pietro; Gianolli, Luigi; Perani, Daniela

2018-05-25

Even though the benefits of radiation therapy are well established, it is important to recognize the broad spectrum of radiation-induced changes, particularly in the central nervous system. The possible damage to the brain parenchyma may have clinical consequences and in particular cognitive impairment might be one of the major complication of radiotherapy. To date, no studies have investigated the effects of focal radiation therapy on brain structure and function together with the assessment of their clinical outcomes at a long follow-up. In this prospective study, we evaluated in six patients the possible brain late effects after radiation therapy, using a standardized neuropsychological battery, MRI and 18F-FDG PET using SPM and semi-quantitative methods, in patients affected by cranial base tumors who underwent gamma knife or tomotherapy. Neuropsychological examinations showed no cognitive impairment after the treatment. In all patients, both MRI assessment and 18F-FDG-PET did not reveal any local or distant anatomical and metabolic late effects. The present study support the safety of advanced radiation therapy techniques. 18F-FDG-PET, using SPM and semi-quantitative methods, might be a valuable tool to evaluate the cerebral radiotoxicity in patients treated for brain neoplasms. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Medical Therapy for Cushing's Syndrome in the Twenty-first Century.

PubMed

Tritos, Nicholas A; Biller, Beverly M K

2018-06-01

Medical therapy has a useful adjunctive role in many patients with Cushing's syndrome. Patients with pituitary corticotroph adenomas who have received radiation therapy to the sella require medical therapy until the effects of radiation therapy occur. In addition, patients with Cushing's syndrome who cannot undergo surgery promptly, including those who are acutely ill and cannot safely undergo tumor resection, may benefit from medical therapy as a bridge to surgery. Other possible candidates for medical therapy are those with unresectable tumors or those whose tumor location remains unknown despite adequate diagnostic evaluation. Copyright © 2018 Elsevier Inc. All rights reserved.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Xi-Mei; Department of Radiation Oncology, Tianjin Medical University Cancer Institute and Hospital, Tianjin; Li, Ye-Xiong, E-mail: yexiong@yahoo.com

Purpose: Early stage peripheral T-cell lymphoma, not otherwise specified (PTCL-NOS) is rare. The purpose of this study was to evaluate the outcome of treatment as well as the potential role of radiation therapy in PTCL-NOS. Methods and Materials: Thirty-five patients with early stage PTCL-NOS were included. There were 13 patients with stage I disease and 22 with stage II. All patients except 1 received doxorubicin-based chemotherapy alone (n=13) or a combination of chemotherapy and radiation therapy (CMT) (n=21). Results: The 3-year overall survival (OS) and progression-free survival (PFS) rates for the entire group were 41.3% and 25.7%, respectively. The additionmore » of radiation therapy to chemotherapy significantly improved OS and PFS in early stage PTCL-NOS. The 3-year OS and PFS rates were 49.7% and 33.3% for CMT, compared with 23.1% (P=.042) and 15.4% (P=.035) for chemotherapy alone, respectively. The prognosis for patients who achieved a complete response (CR) was significantly better than that observed in those who did not achieve a CR. Conclusions: Despite the aggressive clinical course of early stage PTCL-NOS, additional radiation therapy has a significant impact on outcome. The integration of local radiation therapy into more effective systemic therapies may further improve survival.« less

TOPICAL REVIEW: A review of dosimetry studies on external-beam radiation treatment with respect to second cancer induction

NASA Astrophysics Data System (ADS)

Xu, X. George; Bednarz, Bryan; Paganetti, Harald

2008-07-01

It has been long known that patients treated with ionizing radiation carry a risk of developing a second cancer in their lifetimes. Factors contributing to the recently renewed concern about the second cancer include improved cancer survival rate, younger patient population as well as emerging treatment modalities such as intensity-modulated radiation treatment (IMRT) and proton therapy that can potentially elevate secondary exposures to healthy tissues distant from the target volume. In the past 30 years, external-beam treatment technologies have evolved significantly, and a large amount of data exist but appear to be difficult to comprehend and compare. This review article aims to provide readers with an understanding of the principles and methods related to scattered doses in radiation therapy by summarizing a large collection of dosimetry and clinical studies. Basic concepts and terminology are introduced at the beginning. That is followed by a comprehensive review of dosimetry studies for external-beam treatment modalities including classical radiation therapy, 3D-conformal x-ray therapy, intensity-modulated x-ray therapy (IMRT and tomotherapy) and proton therapy. Selected clinical data on second cancer induction among radiotherapy patients are also covered. Problems in past studies and controversial issues are discussed. The needs for future studies are presented at the end.

Delayed cerebral radiation necrosis following treatment for a plasmacytoma of the skull.

PubMed

Chambless, Lola B; Angel, Federica B; Abel, Ty W; Xia, Fen; Weaver, Kyle D

2010-10-25

Cerebral radiation necrosis is a relatively common complication of radiation therapy for intracranial malignancies which can also rarely be encountered after radiation of extracranial lesions of the head and neck. We present the first reported case of cerebral radiation necrosis in a patient who underwent radiation therapy for a plasmacytoma of the skull. A 68-year-old male with multiple myeloma presented with an enhancing right frontal mass, 8 years after receiving radiation therapy for a plasmacytoma of the left frontal skull. The patient underwent a diagnostic and therapeutic craniotomy for a presumed neoplastic lesion. The pathologic diagnosis made in this case was delayed radiation necrosis. The patient was followed for over a year during which this process continued to evolve before the ultimate resolution of his clinical symptoms and radiographic abnormality. This case highlights the importance of considering radiation necrosis in the differential diagnosis of any patient with an intracranial mass and a history of radiation for an extracranial head and neck malignancy, regardless of timing and laterality. This case also provides unique insights into the ongoing debate regarding the role of the aberrant immune response in the pathogenesis of delayed cerebral radiation necrosis.

Phenytoin Induced Erythema Multiforme after Cranial Radiation Therapy

PubMed Central

Tekkök, İsmail Hakkı

2015-01-01

The prophylactic use of phenytoin during and after brain surgery and cranial irradiation is a common measure in brain tumor therapy. Phenytoin has been associated with variety of adverse skin reactions including urticaria, erythroderma, erythema multiforme (EM), Stevens-Johnson syndrome, and toxic epidermal necrolysis. EM associated with phenytoin and cranial radiation therapy (EMPACT) is a rare specific entity among patients with brain tumors receiving radiation therapy while on prophylactic anti-convulsive therapy. Herein we report a 41-year-old female patient with left temporal glial tumor who underwent surgery and then received whole brain radiation therapy and chemotherapy. After 24 days of continous prophylactic phenytoin therapy the patient developed minor skin reactions and 2 days later the patient returned with generalized erythamatous and itchy maculopapuler rash involving neck, chest, face, trunk, extremities. There was significant periorbital and perioral edema. Painful mucosal lesions consisting of oral and platal erosions also occurred and prevented oral intake significantly. Phenytoin was discontinued gradually. Systemic admistration of corticosteroids combined with topical usage of steroids for oral lesions resulted in complete resolution of eruptions in 3 weeks. All cutaneous lesions in patients with phenytoin usage with the radiotherapy must be evoluated with suspicion for EM. PMID:26361537

Hormone therapy for prostate cancer

MedlinePlus

... be used: Before radiation or surgery to help shrink tumors Along with radiation therapy for cancer that ... of most androgens in the body. This also shrinks or stops prostate cancer from growing. While effective, ...

Radiation therapy

MedlinePlus

Doroshow JH. Approach to the patient with cancer. In: Goldman L, Schafer AI, eds. Goldman's Cecil Medicine . 25th ed. Philadelphia, PA: Elsevier Saunders; 2016:chap 179. National Cancer Institute. Radiation therapy and you: support for people ...

How Does Proton Radiation Therapy Work?

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lincoln, Don

A cancer diagnosis can be a devastating thing to hear, but new treatments are greatly improving a person’s chance of being cured. In this video, Fermilab’s Dr. Don Lincoln explains the physics of an exciting treatment option, called proton radiation therapy, which is far superior to traditional therapy, at least in some cases.

SU-E-T-211: Peer Review System for Ensuring Quality of Radiation Therapy Treatments.

PubMed

Kapoor, R; Kapur, P; Kumar, S A; Alex, D; Ranka, S; Palta, J

2012-06-01

To demonstrate a Web-based electronic peer review system that has the potential to improve quality of care for radiation therapy patients. The system provides tools that allow radiation oncologists to seek peer review of target and critical structure delineation, treatment plans, and share clinical data with peers to optimize radiation therapy treatments. Peer review of radiation therapy treatment planning data prior to its initiation improves the quality of radiation therapy and clinical outcomes. Web-based access to radiation therapy treatment planning data and medical records mitigate existing geographical and temporal constraints. With internet access, the healthcare provider can access the data from any location and review it in an interactive and collaborative manner. Interoperability standard like DICOM-RT and IHE-RO compliant RT Systems have facilitated the design and implementation of PRS with Silverlight Web technology, .net Framework and SQL Server. Local DICOM-RT archive and cloud based services are deployed to facilitate remote peer reviews. To validate the PRS system, we tested the system for 100 patients with Philips Pinnacle v 9.0 and Varian Eclipse v 8.9 treatment planning system (TPS). We transmitted the DICOM RT data from the TPS to the cloud based services via the PRS local DICOM RT Archive. Various CT simulation based parameters such as orientation of CT, properties of RT structures etc. were compared between the TPS and PRS system. Data integrity of other parameters such as patient demographics (patient name, ID, attending physician etc.) and dose volume related parameters were also evaluated. Such rigorous testing allowed us to optimize the functionalities and clinical implementation of the PRS. We believe that the PRS will improve the quality and safety of a broad spectrum of radiation therapy patients treated in underserved areas while discouraging the overutilization of expensive radiation treatment modalities. This research and development project is supported by the James and Ester King Biomedical Research Program grant # RC1-09KW-09-26829. © 2012 American Association of Physicists in Medicine.

Thermal Modelling of Various Thermal Barrier Coatings in a High Flux Rocket Engine

NASA Technical Reports Server (NTRS)

Nesbitt, James A.

1998-01-01

A thermal model was developed to predict the thermal response of coated and uncoated tubes tested in a H2/O2 rocket engine. Temperatures were predicted for traditional APS ZrO2-Y2O3 thermal barrier coatings, as well as APS and LPPS ZrO2-Y2O3/NiCrAlY cermet coatings. Good agreement was observed between predicted and measured metal temperatures at locations near the tube surface or at the inner tube wall. The thermal model was also used to quantitatively examine the effect of various coating system parameters on the temperatures in the substrate and coating. Accordingly, the effect of the presence a metallic bond coat and the effect of radiation from the surface of the ceramic layer were examined. In addition, the effect of a variation in the values of the thermal conductivity of the ceramic layer was also investigated. It was shown that a variation in the thermal conductivity of the ceramic layer, on the order of that reported in the literature for plasma sprayed ZrO2-Y2O3 coatings, can result in temperature differences in the substrate greater than 100 C, a much greater effect than that due to the presence of a bond coat or radiation from the ceramic layer. The thermal model was also used to predict the thermal response of a coated rod in order to quantify the difference in the metal temperatures between the two substrate geometries in order to explain the previously-observed increased life of coatings on rods over that on tubes. It was shown that for the short duration testing in the rocket engine, the temperature in a tube could exceed that in a rod by more than 100 C. Lastly, a two-dimensional model was developed to evaluate the effect of tangential heat transfer around the tube and its impact on reducing the stagnation point temperature. It was also shown that tangential heat transfer does not significantly reduce the stagnation point temperature, thus allowing application of a simpler, one-dimensional model for comparing measured and predicted stagnation point temperatures.

Some computer graphical user interfaces in radiation therapy.

PubMed

Chow, James C L

2016-03-28

In this review, five graphical user interfaces (GUIs) used in radiation therapy practices and researches are introduced. They are: (1) the treatment time calculator, superficial X-ray treatment time calculator (SUPCALC) used in the superficial X-ray radiation therapy; (2) the monitor unit calculator, electron monitor unit calculator (EMUC) used in the electron radiation therapy; (3) the multileaf collimator machine file creator, sliding window intensity modulated radiotherapy (SWIMRT) used in generating fluence map for research and quality assurance in intensity modulated radiation therapy; (4) the treatment planning system, DOSCTP used in the calculation of 3D dose distribution using Monte Carlo simulation; and (5) the monitor unit calculator, photon beam monitor unit calculator (PMUC) used in photon beam radiation therapy. One common issue of these GUIs is that all user-friendly interfaces are linked to complex formulas and algorithms based on various theories, which do not have to be understood and noted by the user. In that case, user only needs to input the required information with help from graphical elements in order to produce desired results. SUPCALC is a superficial radiation treatment time calculator using the GUI technique to provide a convenient way for radiation therapist to calculate the treatment time, and keep a record for the skin cancer patient. EMUC is an electron monitor unit calculator for electron radiation therapy. Instead of doing hand calculation according to pre-determined dosimetric tables, clinical user needs only to input the required drawing of electron field in computer graphical file format, prescription dose, and beam parameters to EMUC to calculate the required monitor unit for the electron beam treatment. EMUC is based on a semi-experimental theory of sector-integration algorithm. SWIMRT is a multileaf collimator machine file creator to generate a fluence map produced by a medical linear accelerator. This machine file controls the multileaf collimator to deliver intensity modulated beams for a specific fluence map used in quality assurance or research. DOSCTP is a treatment planning system using the computed tomography images. Radiation beams (photon or electron) with different energies and field sizes produced by a linear accelerator can be placed in different positions to irradiate the tumour in the patient. DOSCTP is linked to a Monte Carlo simulation engine using the EGSnrc-based code, so that 3D dose distribution can be determined accurately for radiation therapy. Moreover, DOSCTP can be used for treatment planning of patient or small animal. PMUC is a GUI for calculation of the monitor unit based on the prescription dose of patient in photon beam radiation therapy. The calculation is based on dose corrections in changes of photon beam energy, treatment depth, field size, jaw position, beam axis, treatment distance and beam modifiers. All GUIs mentioned in this review were written either by the Microsoft Visual Basic.net or a MATLAB GUI development tool called GUIDE. In addition, all GUIs were verified and tested using measurements to ensure their accuracies were up to clinical acceptable levels for implementations.

Accuracy and Utility of Deformable Image Registration in {sup 68}Ga 4D PET/CT Assessment of Pulmonary Perfusion Changes During and After Lung Radiation Therapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hardcastle, Nicholas, E-mail: nick.hardcastle@gmail.com; Centre for Medical Radiation Physics, University of Wollongong, Wollongong; Hofman, Michael S.

2015-09-01

Purpose: Measuring changes in lung perfusion resulting from radiation therapy dose requires registration of the functional imaging to the radiation therapy treatment planning scan. This study investigates registration accuracy and utility for positron emission tomography (PET)/computed tomography (CT) perfusion imaging in radiation therapy for non–small cell lung cancer. Methods: {sup 68}Ga 4-dimensional PET/CT ventilation-perfusion imaging was performed before, during, and after radiation therapy for 5 patients. Rigid registration and deformable image registration (DIR) using B-splines and Demons algorithms was performed with the CT data to obtain a deformation map between the functional images and planning CT. Contour propagation accuracy andmore » correspondence of anatomic features were used to assess registration accuracy. Wilcoxon signed-rank test was used to determine statistical significance. Changes in lung perfusion resulting from radiation therapy dose were calculated for each registration method for each patient and averaged over all patients. Results: With B-splines/Demons DIR, median distance to agreement between lung contours reduced modestly by 0.9/1.1 mm, 1.3/1.6 mm, and 1.3/1.6 mm for pretreatment, midtreatment, and posttreatment (P<.01 for all), and median Dice score between lung contours improved by 0.04/0.04, 0.05/0.05, and 0.05/0.05 for pretreatment, midtreatment, and posttreatment (P<.001 for all). Distance between anatomic features reduced with DIR by median 2.5 mm and 2.8 for pretreatment and midtreatment time points, respectively (P=.001) and 1.4 mm for posttreatment (P>.2). Poorer posttreatment results were likely caused by posttreatment pneumonitis and tumor regression. Up to 80% standardized uptake value loss in perfusion scans was observed. There was limited change in the loss in lung perfusion between registration methods; however, Demons resulted in larger interpatient variation compared with rigid and B-splines registration. Conclusions: DIR accuracy in the data sets studied was variable depending on anatomic changes resulting from radiation therapy; caution must be exercised when using DIR in regions of low contrast or radiation pneumonitis. Lung perfusion reduces with increasing radiation therapy dose; however, DIR did not translate into significant changes in dose–response assessment.« less

Shock-like structures in the tropical cyclone boundary layer

NASA Astrophysics Data System (ADS)

Williams, Gabriel J.; Taft, Richard K.; McNoldy, Brian D.; Schubert, Wayne H.

2013-06-01

This paper presents high horizontal resolution solutions of an axisymmetric, constant depth, slab boundary layer model designed to simulate the radial inflow and boundary layer pumping of a hurricane. Shock-like structures of increasing intensity appear for category 1-5 hurricanes. For example, in the category 3 case, the u>(∂u/∂r>) term in the radial equation of motion produces a shock-like structure in the radial wind, i.e., near the radius of maximum tangential wind the boundary layer radial inflow decreases from approximately 22 m s-1 to zero over a radial distance of a few kilometers. Associated with this large convergence is a spike in the radial distribution of boundary layer pumping, with updrafts larger than 22 m s-1 at a height of 1000 m. Based on these model results, it is argued that observed hurricane updrafts of this magnitude so close to the ocean surface are attributable to the dry dynamics of the frictional boundary layer rather than moist convective dynamics. The shock-like structure in the boundary layer radial wind also has important consequences for the evolution of the tangential wind and the vertical component of vorticity. On the inner side of the shock the tangential wind tendency is essentially zero, while on the outer side of the shock the tangential wind tendency is large due to the large radial inflow there. The result is the development of a U-shaped tangential wind profile and the development of a thin region of large vorticity. In many respects, the model solutions resemble the remarkable structures observed in the boundary layer of Hurricane Hugo (1989).

Tangential synthetic jets for separation control

NASA Astrophysics Data System (ADS)

Esmaeili Monir, H.; Tadjfar, M.; Bakhtian, A.

2014-02-01

A numerical study of separation control has been made to investigate aerodynamic characteristics of a NACA23012 airfoil with a tangential synthetic jet. Simulations are carried out at the chord Reynolds number of Re=2.19×106. The present approach relies on solving the Unsteady Reynolds-Averaged Navier-Stokes (URANS) equations. The turbulence model used in the present computation is the Spalart-Allmaras one-equation model. All computations are performed with a finite volume based code. Stall characteristics are significantly improved by controlling the formation of separation vortices in the flow. We placed the synthetic jet at the 12% chord, xj=0.12c, where we expected the separation to occur. Two distinct jet oscillating frequencies: Fj+=0.159 and Fj+=1 were considered. We studied the effect of blowing ratio, Vj/U∞, where it was varied from 0 to 5. The inclined angle of the synthetic jet was varied from αj=0° up to αj=83°. For the non-zero inclined angles, the local maximum in the aerodynamic performance, Cl/Cd, of 6.89 was found for the inclined angle of about 43°. In the present method, by means of creating a dent on the airfoil, linear momentum is transferred to the flow system in tangential direction to the airfoil surface. Thus the absolute maximum of 11.19 was found for the tangential synthetic jet at the inclined angle of the jet of 0°. The mechanisms involved for a tangential jet appear to behave linearly, as by multiplying the activation frequency of the jet by a factor produces the same multiplication factor in the resulting frequency in the flow. However, the mechanisms involved in the non-zero inclined angle cases behave nonlinearly when the activation frequency is multiplied.

Radiation Therapy (For Parents)

MedlinePlus

... temporary, it can be permanent. Sore Mouth and Tooth Decay The tissues of the mouth may be sore ... and there may be an increased risk of tooth decay if a child received radiation therapy to the ...

Development and evaluation of multi-energy PbO dosimeter for quality assurance of image-guide radiation therapy devices

NASA Astrophysics Data System (ADS)

Kim, Kyo-Tae; Heo, Ye-Ji; Han, Moo-Jae; Oh, Kyung-Min; Lee, Young-Kyu; Kim, Shin-Wook; Park, Sung-Kwang

2017-04-01

In radiation therapy, accurate radiotherapy treatment plan (RTP) reproduction is necessary to optimize the clinical results. Thus, attempts have recently been made to ensure high RTP reproducibility using image-guide radiation therapy (IGRT) technology. However, the clinical use of digital X-ray equipment requires extended quality assurance (QA) for those devices, since the IGRT device quality determines the precision of intensity-modulated radiation therapy. The study described in this paper was focused on developing a multi-energy PbO dosimeter for IGRT device QA. The Schottky-type polycrystalline PbO dosimeter with a Au/PbO/ITO structure was evaluated by comparing its response coincidence, dose linearity, measurement reproducibility, linear attenuation coefficient, and percent depth dose with those of Si diode and standard ionization chamber dosimeters.

Radiation shielding design of a new tomotherapy facility.

PubMed

Zacarias, Albert; Balog, John; Mills, Michael

2006-10-01

It is expected that intensity modulated radiation therapy (IMRT) and image guided radiation therapy (IGRT) will replace a large portion of radiation therapy treatments currently performed with conventional MLC-based 3D conformal techniques. IGRT may become the standard of treatment in the future for prostate and head and neck cancer. Many established facilities may convert existing vaults to perform this treatment method using new or upgraded equipment. In the future, more facilities undoubtedly will be considering de novo designs for their treatment vaults. A reevaluation of the design principles used in conventional vault design is of benefit to those considering this approach with a new tomotherapy facility. This is made more imperative as the design of the TomoTherapy system is unique in several aspects and does not fit well into the formalism of NCRP 49 for a conventional linear accelerator.

Are We Ready for Positron Emission Tomography/Computed Tomography-based Target Volume Definition in Lymphoma Radiation Therapy?

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yeoh, Kheng-Wei; Mikhaeel, N. George, E-mail: George.Mikhaeel@gstt.nhs.uk

2013-01-01

Fluorine-18 fluorodeoxyglucose (FDG)-positron emission tomography (PET)/computed tomography (CT) has become indispensable for the clinical management of lymphomas. With consistent evidence that it is more accurate than anatomic imaging in the staging and response assessment of many lymphoma subtypes, its utility continues to increase. There have therefore been efforts to incorporate PET/CT data into radiation therapy decision making and in the planning process. Further, there have also been studies investigating target volume definition for radiation therapy using PET/CT data. This article will critically review the literature and ongoing studies on the above topics, examining the value and methods of adding PET/CTmore » data to the radiation therapy treatment algorithm. We will also discuss the various challenges and the areas where more evidence is required.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kennedy, Colin, E-mail: crk1@soton.ac.uk; Bull, Kim; Chevignard, Mathilde

Purpose: To compare quality of survival in “standard-risk” medulloblastoma after hyperfractionated radiation therapy of the central nervous system with that after standard radiation therapy, combined with a chemotherapy regimen common to both treatment arms, in the PNET4 randomised controlled trial. Methods and Materials: Participants in the PNET4 trial and their parents/caregivers in 7 participating anonymized countries completed standardized questionnaires in their own language on executive function, health status, behavior, health-related quality of life, and medical, educational, employment, and social information. Pre- and postoperative neurologic status and serial heights and weights were also recorded. Results: Data were provided by 151 ofmore » 244 eligible survivors (62%) at a median age at assessment of 15.2 years and median interval from diagnosis of 5.8 years. Compared with standard radiation therapy, hyperfractionated radiation therapy was associated with lower (ie, better) z-scores for executive function in all participants (mean intergroup difference 0.48 SDs, 95% confidence interval 0.16-0.81, P=.004), but health status, behavioral difficulties, and health-related quality of life z-scores were similar in the 2 treatment arms. Data on hearing impairment were equivocal. Hyperfractionated radiation therapy was also associated with greater decrement in height z-scores (mean intergroup difference 0.43 SDs, 95% confidence interval 0.10-0.76, P=.011). Conclusions: Hyperfractionated radiation therapy was associated with better executive function and worse growth but without accompanying change in health status, behavior, or quality of life.« less

Adenoid cystic carcinoma of the lacrimal gland.

PubMed

Sanders, Jason C; Mendenhall, William M; Werning, John W

2016-01-01

This is a retrospective analysis of the 50-year University of Florida experience treating adenoid cystic carcinoma of the lacrimal gland with radiation therapy. Between 1965 and 2015, 8 patients with adenoid cystic carcinoma of the lacrimal gland received radiation therapy with curative intent. Four patients received postoperative radiation therapy and 4 received definitive radiation therapy alone. The median follow-up was 3.3 years (range, 0.3 to 11.2 years). All 4 patients who received postoperative radiation therapy received 74.4 Gy. The 4 patients who received radiation therapy alone received a median dose of 72.3 Gy (range, 70.0 to 74.4 Gy). The overall survival rates at 5 and 10 years were 25% and 13%, respectively. The cause-specific survival rates at 5 and 10 years were 29% and 14%, respectively. The local control and freedom from metastases rates at 5 and 10 years were both 43%. Local recurrences occurred in 50% of patients, and distant metastatic disease occurred in 38% of patients. No patients experienced acute complications of treatment that warranted a treatment break. Two patients experienced bone exposure as late complications of treatment. The results of this study illustrate the propensity for adenoid cystic carcinoma of the lacrimal gland to recur both locally and with distant metastases despite aggressive local treatment measures. This study also demonstrates the relatively poor outcomes for individuals with this type of tumor. Copyright © 2016 Elsevier Inc. All rights reserved.

Biochemical Response to Androgen Deprivation Therapy Before External Beam Radiation Therapy Predicts Long-term Prostate Cancer Survival Outcomes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zelefsky, Michael J., E-mail: zelefskm@mskcc.org; Gomez, Daniel R.; Polkinghorn, William R.

2013-07-01

Purpose: To determine whether the response to neoadjuvant androgen deprivation therapy (ADT) defined by a decline in prostate-specific antigen (PSA) to nadir values is associated with improved survival outcomes after external beam radiation therapy (EBRT) for prostate cancer. Methods and Materials: One thousand forty-five patients with localized prostate cancer were treated with definitive EBRT in conjunction with neoadjuvant and concurrent ADT. A 6-month course of ADT was used (3 months during the neoadjuvant phase and 2 to 3 months concurrently with EBRT). The median EBRT prescription dose was 81 Gy using a conformal-based technique. The median follow-up time was 8.5more » years. Results: The 10-year PSA relapse-free survival outcome among patients with pre-radiation therapy PSA nadirs of ≤0.3 ng/mL was 74.3%, compared with 57.7% for patients with higher PSA nadir values (P<.001). The 10-year distant metastases-free survival outcome among patients with pre-radiation therapy PSA nadirs of ≤0.3 ng/mL was 86.1%, compared with 78.6% for patients with higher PSA nadir values (P=.004). In a competing-risk analysis, prostate cancer-related deaths were also significantly reduced among patients with pre-radiation therapy PSA nadirs of <0.3 ng/mL compared with higher values (7.8% compared with 13.7%; P=.009). Multivariable analysis demonstrated that the pre-EBRT PSA nadir value was a significant predictor of long-term biochemical tumor control, distant metastases-free survival, and cause-specific survival outcomes. Conclusions: Pre-radiation therapy nadir PSA values of ≤0.3 ng/mL after neoadjuvant ADT were associated with improved long-term biochemical tumor control, reduction in distant metastases, and prostate cancer-related death. Patients with higher nadir values may require alternative adjuvant therapies to improve outcomes.« less

International Patterns of Practice in the Management of Radiation Therapy-induced Nausea and Vomiting

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dennis, Kristopher; Zhang Liying; Lutz, Stephen

Purpose: To investigate international patterns of practice in the management of radiation therapy-induced nausea and vomiting (RINV). Methods and Materials: Oncologists prescribing radiation therapy in the United States, Canada, The Netherlands, Australia, New Zealand, Spain, Italy, France, Hong Kong, Singapore, Cyprus, and Israel completed a Web-based survey that was based on 6 radiation therapy-only clinical cases modeled after the minimal-, low-, moderate-, and high-emetic risk levels defined in the antiemetic guidelines of the American Society of Clinical Oncology and the Multinational Association of Supportive Care in Cancer. For each case, respondents estimated the risks of nausea and vomiting separately andmore » committed to an initial management approach. Results: In total, 1022 responses were received. Risk estimates and management decisions for the minimal- and high-risk cases varied little and were in line with guideline standards, whereas those for the low- and moderate-risk cases varied greatly. The most common initial management strategies were as follows: rescue therapy for a minimal-risk case (63% of respondents), 2 low-risk cases (56% and 80%), and 1 moderate-risk case (66%); and prophylactic therapy for a second moderate-risk case (75%) and a high-risk case (95%). The serotonin (5-HT){sub 3} receptor antagonists were the most commonly recommended prophylactic agents. On multivariate analysis, factors predictive of a decision for prophylactic or rescue therapy were risk estimates of nausea and vomiting, awareness of the American Society of Clinical Oncology antiemetic guideline, and European Society for Therapeutic Radiology and Oncology membership. Conclusions: Risk estimates and management strategies for RINV varied, especially for low- and moderate-risk radiation therapy cases. Radiation therapy-induced nausea and vomiting are under-studied treatment sequelae. New observational and translational studies are needed to allow for individual patient risk assessment and to refine antiemetic guideline management recommendations.« less

Radiation treatment for newly diagnosed esophageal cancer with prior radiation to the thoracic cavity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sponseller, Patricia, E-mail: sponselp@uw.edu; Lenards, Nishele; Kusano, Aaron

2014-10-01

The purpose of this report is to communicate the use of single-positron emission computed tomography scan in planning radiation treatments for patients with a history of radiation to the thoracic cavity. A patient presented with obstructive esophageal cancer, having previously received chemotherapy and radiation therapy to the mediastinum for non-Hodgkin lymphoma 11 years earlier. Owing to a number of comorbidities, the patient was not a surgical candidate and was referred to the University of Washington Medical Center for radiation therapy. Prior dose to the spinal cord and lung were taken into account before designing the radiation treatment plan.

Lung Cancer Prevention

MedlinePlus

... is a risk factor for lung cancer. Atomic bomb radiation, radiation therapy , imaging tests , and radon are sources of radiation exposure: Atomic bomb radiation: Being exposed to radiation after an atomic ...

Dosimetric and radiobiological comparison of Forward Tangent Intensity Modulated Radiation Therapy (FT-IMRT) and Volumetric Modulated Arc Therapy (VMAT) for early stage whole breast cancer

NASA Astrophysics Data System (ADS)

Moshiri Sedeh, Nader

Intensity Modulated Radiation Therapy (IMRT) is a well-known type of external beam radiation therapy. The advancement in technology has had an inevitable influence in radiation oncology as well that has led to a newer and faster dose delivery technique called Volumetric Modulated Arc Therapy (VMAT). Since the presence of the VMAT modality in clinics in the late 2000, there have been many studies in order to compare the results of the VMAT modality with the current popular modality IMRT for various tumor sites in the body such as brain, prostate, head and neck, cervix and anal carcinoma. This is the first study to compare VMAT with IMRT for breast cancer. The results show that the RapidArc technique in Eclipse version 11 does not improve all aspects of the treatment plans for the breast cases automatically and easily, but it needs to be manipulated by extra techniques to create acceptable plans thus further research is needed.

Treatment of left sided breast cancer for a patient with funnel chest: Volumetric-modulated arc therapy vs. 3D-CRT and intensity-modulated radiotherapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Haertl, Petra M., E-mail: petra.haertl@klinik.uni-regensburg.de; Pohl, Fabian; Weidner, Karin

2013-04-01

This case study presents a rare case of left-sided breast cancer in a patient with funnel chest, which is a technical challenge for radiation therapy planning. To identify the best treatment technique for this case, 3 techniques were compared: conventional tangential fields (3D conformal radiotherapy [3D-CRT]), intensity-modulated radiotherapy (IMRT), and volumetric-modulated arc therapy (VMAT). The plans were created for a SynergyS® (Elekta, Ltd, Crawley, UK) linear accelerator with a BeamModulator™ head and 6-MV photons. The planning system was Oncentra Masterplan® v3.3 SP1 (Nucletron BV, Veenendal, Netherlands). Calculations were performed with collapsed cone algorithm. Dose prescription was 50.4 Gy to themore » average of the planning target volume (PTV). PTV coverage and homogeneity was comparable for all techniques. VMAT allowed reducing dose to the ipsilateral organs at risk (OAR) and the contralateral breast compared with IMRT and 3D-CRT: The volume of the left lung receiving 20 Gy was 19.3% for VMAT, 26.1% for IMRT, and 32.4% for 3D-CRT. In the heart, a D{sub 15%} of 9.7 Gy could be achieved with VMAT compared with 14 Gy for IMRT and 46 Gy for 3D-CRT. In the contralateral breast, D{sub 15%} was 6.4 Gy for VMAT, 8.8 Gy for IMRT, and 10.2 Gy for 3D-CRT. In the contralateral lung, however, the lowest dose was achieved with 3D-CRT with D{sub 10%} of 1.7 Gy for 3D-CRT, and 6.7 Gy for both IMRT and VMAT. The lowest number of monitor units (MU) per 1.8-Gy fraction was required by 3D-CRT (192 MU) followed by VMAT (518 MU) and IMRT (727 MU). Treatment time was similar for 3D-CRT (3 min) and VMAT (4 min) but substantially increased for IMRT (13 min). VMAT is considered the best treatment option for the presented case of a patient with funnel chest. It allows reducing dose in most OAR without compromising target coverage, keeping delivery time well below 5 minutes.« less