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Sample records for resulting radiation doses

  1. Conservative surgery for low rectal carcinoma after high-dose radiation. Functional and oncologic results.

    PubMed Central

    Rouanet, P; Fabre, J M; Dubois, J B; Dravet, F; Saint Aubert, B; Pradel, J; Ychou, M; Solassol, C; Pujol, H

    1995-01-01

    OBJECTIVE: Using a prospective, nonrandomized study, the authors evaluated the morbidity and functional and oncologic results of conservative surgery for cancer of the lower third of the rectum after high-dose radiation. SUMMARY BACKGROUND DATA: Colo-anal anastomosis has made sphincter conservation for low rectal carcinoma technically feasible. The limits to conservative surgery currently are oncologic rather than technical. Adjuvant radiotherapy has proven its benefit in terms of regional control, with a dose relationship. METHODS: Since June 1990, 27 patients with distal rectal adenocarcinoma were treated by preoperative radiotherapy (40 + 20 Gy delivered with three fields) and curative surgery. The mean distance from the anal verge was 47 mm (27-57 mm), and none of the tumors were fixed (15 T2, 12 T3). RESULTS: Mortality and morbidity were not increased by high-dose preoperative radiation. Twenty-one patients underwent conservative surgery (78%-17 total proctectomies and colo-anal anastomoses, 4 trans-anal resections). After colo-anal anastomosis, all patients with colonic pouch had good results; two patients had moderate results and one patient had poor results after straight colo-anal anastomosis. With a mean follow-up of 24 months, the authors noted 1 postoperative death, 2 disease-linked deaths, 1 controlled regional recurrence, 2 evolutive patients with pulmonary metastases, and 21 disease-free patients. CONCLUSIONS: These first results confirm the possibility of conservative surgery for low rectal carcinoma after high-dose radiation. A prospective, randomized trial could be induced to determine the real role of the 20 Gy boost on the sphincter-saving decision. PMID:7826163

  2. Selective fallopian tube catheterisation in female infertility: clinical results and absorbed radiation dose.

    PubMed

    Nakamura, K; Ishiguchi, T; Maekoshi, H; Ando, Y; Tsuzaka, M; Tamiya, T; Suganuma, N; Ishigaki, T

    1996-01-01

    Clinical results of fluoroscopic fallopian tube catheterisation and absorbed radiation doses during the procedure were evaluated in 30 infertility patients with unilateral or bilateral tubal obstruction documented on hysterosalpingography. The staged technique consisted of contrast injection through an intrauterine catheter with a vacuum cup device, ostial salpingography with the wedged catheter, and selective salpingography with a coaxial microcatheter. Of 45 fallopian tubes examined, 35 (78%) were demonstrated by the procedure, and at least one tube was newly demonstrated in 26 patients (87%). Six of these patients conceived spontaneously in the follow-up period of 1-11 months. Four pregnancies were intrauterine and 2 were ectopic. This technique provided accurate and detailed information in the diagnosis and treatment of tubal obstruction in infertility patients. The absorbed radiation dose to the ovary in the average standardised procedure was estimated to be 0.9 cGy. Further improvement in the X-ray equipment and technique is required to reduce the radiation dose. PMID:8798025

  3. Radiation doses in adult computed tomography practice in Serbia: initial results.

    PubMed

    Arandjic, Danijela; Ciraj-Bjelac, Olivera; Hadnadjev, Darka; Stojanovic, Sanja; Bozovic, Predrag; Ceklic, Sandra; Lazarevic, Djordje

    2014-11-01

    This work presents initial data on radiation doses in adult computed tomography (CT) in Serbia. Data were collected in terms of CT dose index (CTDIvol) and dose length product (DLP) values for head, chest and abdomen examination. The range of CTDIvol values was found to be 53-98, 11-34 and 8.5-227 mGy whereas for DLP was 803-1066, 350-845 and 1066-3078 mGy cm(-1) for head, chest and abdomen examination, respectively. Except for abdomen on one CT unit, all estimated values were in line with the reported data. This work also presents simple method on how to reduce radiation doses when scanning head. Using axial (step-and-shot) instead of helical mode and decreasing tube current-time product leads to significant dose reduction. CTDIvol was decreased by 20 % whereas DLP was reduced for a factor 2. PMID:25063787

  4. Higher Chest Wall Dose Results in Improved Locoregional Outcome in Patients Receiving Postmastectomy Radiation

    SciTech Connect

    Panoff, Joseph E.; Takita, Cristiane; Hurley, Judith; Reis, Isildinha M.; Zhao, Wei; Rodgers, Steven E.; Gunaseelan, Vijayalakshmi; Wright, Jean L.

    2012-03-01

    Purpose: Randomized trials demonstrating decreased locoregional recurrence (LRR) and improved overall survival (OS) in women receiving postmastectomy radiation therapy (PMRT) used up to 50 Gy to the chest wall (CW), but in practice, many centers boost the CW dose to {>=}60 Gy, despite lack of data supporting this approach. We evaluated the relationship between CW dose and clinical outcome. Methods and Materials: We retrospectively reviewed medical records of 582 consecutively treated patients who received PMRT between January 1999 and December 2009. We collected data on patient, disease, treatment characteristics, and outcomes of LRR, progression-free survival (PFS) and OS. Results: Median follow-up from the date of diagnosis was 44.7 months. The cumulative 5-year incidence of LRR as first site of failure was 6.2%. CW dose for 7% (43 patients) was {<=}50.4 Gy (range, 41.4-50.4 Gy) and 93% received >50.4 Gy (range, 52.4-74.4 Gy). A CW dose of >50.4 Gy vs. {<=}50.4 Gy was associated with lower incidence of LRR, a 60-month rate of 5.7% (95% confidence interval [CI], 3.7-8.2) vs. 12.7% (95% CI, 4.5-25.3; p = 0.054). Multivariate hazard ratio (HR) for LRR controlling for race, receptor status, and stage was 2.62 (95% CI, 1.02-7.13; p = 0.042). All LRR in the low-dose group occurred in patients receiving 50 to 50.4 Gy. Lower CW dose was associated with worse PFS (multivariate HR, 2.73; 95% CI, 1.64-4.56; p < 0.001) and OS (multivariate HR, 3.88; 95% CI, 2.16-6.99; p < 0.001). Conclusions: The addition of a CW boost above 50.4 Gy resulted in improved locoregional control and survival in this cohort patients treated with PMRT for stage II-III breast cancer. The addition of a CW boost to standard-dose PMRT is likely to benefit selected high-risk patients. The optimal technique, target volume, and patient selection criteria are unknown. The use of a CW boost should be studied prospectively, as has been done in the setting of breast conservation.

  5. Patient radiation doses in the most common interventional cardiology procedures in Croatia: first results.

    PubMed

    Brnić, Z; Krpan, T; Faj, D; Kubelka, D; Ramac, J Popić; Posedel, D; Steiner, R; Vidjak, V; Brnić, V; Visković, K; Baraban, V

    2010-02-01

    Apart from its benefits, the interventional cardiology (IC) is known to generate high radiation doses to patients and medical staff involved. The European Union Medical Exposures Directive 97/43/Euroatom strongly recommend patient dosimetry in interventional radiology, including IC. IC patient radiation doses in four representative IC rooms in Croatia were investigated. Setting reference levels for these procedures have difficulties due to the large difference in procedure complexity. Nevertheless, it is important that some guideline values are available as a benchmark to guide the operators during these potentially high-dose procedures. Local and national diagnostic reference levels (DRLs) were proposed as a guidance. A total of 138 diagnostic (coronary angiography, CA) and 151 therapeutic (PTCA, stenting) procedures were included. Patient irradiation was measured in terms of kerma-area product (KAP), fluoroscopy time (FT) and number of cine-frames (F). KAP was recorded using calibrated KAP-meters. DRLs of KAP, FT and F were calculated as third quartile values rounded up to the integer. Skin doses were assessed on a selected sample of high skin dose procedures, using radiochromic films, and peak skin doses (PSD) were presented. A relative large range of doses in IC was detected. National DRLs were proposed as follows: 32 Gy cm(2), 6.6 min and 610 frames for CA and 72 Gy cm(2), 19 min and 1270 frames for PTCA. PSD <1 Gy were measured in 72 % and PSD >2 Gy in 8 % of selected patients. Measuring the patient doses in radiological procedures is required by law, but rarely implemented in Croatia. The doses recorded in the study are acceptable when compared with the literature, but optimisation is possible. The preliminary DRL values proposed may be used as a guideline for local departments, and should be a basis for radiation reduction measures and quality assurance programmes in IC in Croatia. PMID:19880413

  6. Offsite radiation doses from Hanford Operations for the years 1983 through 1987: A comparison of results calculated by two methods

    SciTech Connect

    Soldat, J.K.

    1989-10-01

    This report compares the results of the calculation of potential radiation doses to the public by two different environmental dosimetric systems for the years 1983 through 1987. Both systems project the environmental movement of radionuclides released with effluents from Hanford operations; their concentrations in air, water, and foods; the intake of radionuclides by ingestion and inhalation; and, finally, the potential radiation doses from radionuclides deposited in the body and from external sources. The first system, in use for the past decade at Hanford, calculates radiation doses in terms of 50-year cumulative dose equivalents to body organs and to the whole body, based on the methodology defined in ICRP Publication 2. This system uses a suite of three computer codes: PABLM, DACRIN, and KRONIC. In the new system, 50-year committed doses are calculated in accordance with the recommendations of the ICRP Publications 26 and 30, which were adopted by the US Department of Energy (DOE) in 1985. This new system calculates dose equivalent (DE) to individual organs and effective dose equivalent (EDE). The EDE is a risk-weighted DE that is designed to be an indicator of the potential health effects arising from the radiation dose. 16 refs., 1 fig., 38 tabs.

  7. SU-E-J-204: Radiation Dose to Patients Resulting From Image Guidance Procedures and AAPM TG-180 Update

    SciTech Connect

    Ding, G; Alaei, P

    2014-06-01

    Purpose: Image-guided radiation therapy (IGRT) is the new paradigm for patient positioning and target localization in radiotherapy. Daily imaging procedures add additional dose to the patient's treatment volume and normal tissues and may expose the organs at risk to unaccounted doses. This presentation is to update the progress of AAPM TG-180 which aims to provide strategies to quantify and account the dose from both MV and kV imaging in patient treatment planning. Methods: Our current knowledge on image guidance dose is presented. A summary of doses from image guidance procedures delivered to patients in relationship with therapeutic doses is given. Different techniques in reducing the image guidance dose are summarized. Typical organ doses resulting from different image acquisition procedures used in IGRT are tabulated. Results: Many techniques to reduce the imaging doses are available in clinical applications. There are large variations between dose to bone and dose to soft tissues for x-rays at kilovoltage energy range. Methods for clinical implementation of accounting for the imaging dose from an imaging procedure are available. Beam data from imaging systems can be generated by combining Monte Carlo simulations and experimental measurements for commissioning imaging beams in the treatment planning. Conclusion: The current treatment planning systems are not yet equipped to perform patient specific dose calculations resulting from kV imaging procedures. The imaging dose from current kV image devices has been significantly reduced and is generally much less than that resulting from MV. Because the magnitude of kV imaging dose is significantly low and the variation between patients is modest, it is feasible to estimate dose based on imaging producers or protocols using tabulated values which provides an alternative to accomplish the task of accounting and reporting imaging doses.

  8. Radiation Dose Survey for Common Computed Tomography Exams: 2013 British Columbia Results.

    PubMed

    Thakur, Yogesh; Bjarnason, Thorarin A; Baxter, Patricia; Griffith, Mitch; Eaton, Kirk

    2016-02-01

    In 2013 Health Canada conducted a national survey of computed tomography (CT) radiation usage. We analysed contributions from all 7 public health authorities in the province of British Columbia, which covered scanner age, number of slices, and common adult protocols (≥ 19 years: 70 ± 20 kg, head, chest, abdomen/pelvis, and trunk). Patient doses were recorded for common protocols. Diagnostic reference levels (DRLs) was calculated using scanner data with >10 patient doses recorded for each protocol. Data was analysed based on image reconstruction (filtered backprojection vs iterative reconstruction [IR] vs IR available but not in use). Provincial response was 92%, with 59 of 64 CT data used for analysis. The average scanner age was 5.5 years old, with 39% of scanners installed between 2008-2013; 78.5% of scanners were multislice (>64 slices), and 44% of scanners had IR available. Overall British Columbia DRLs were: head = 1305, chest = 529, abdomen/pelvis = 819, and trunk = 1225. DRLs were consistent with Health Canada recommendations and other Canadian published values, but above international standards. For sites with IR available, less than 50% used this technology routinely for head, chest and trunk exams. Overall, use of IR reduced radiation usage between 11%-32% compared to filtered backprojection, while sites using IR vs IR available used 30%/43% less radiation for head/chest exams (P < .05). No significant difference was observed for abdomen/pelvis exams (P = .385). With the fast pace of CT technical advancement, DRLs should reflect the technology used, instead of just globally applied to anatomical regions. Federal guidelines should be updated at a higher frequency to reflect new technology. In addition, new technologies must be utilised to optimize image quality vs radiation usage. PMID:26608253

  9. Multileaf Collimator Tracking Improves Dose Delivery for Prostate Cancer Radiation Therapy: Results of the First Clinical Trial

    SciTech Connect

    Colvill, Emma; Booth, Jeremy T.; O'Brien, Ricky T.; Eade, Thomas N.; Kneebone, Andrew B.; Poulsen, Per R.; Keall, Paul J.

    2015-08-01

    Purpose: To test the hypothesis that multileaf collimator (MLC) tracking improves the consistency between the planned and delivered dose compared with the dose without MLC tracking, in the setting of a prostate cancer volumetric modulated arc therapy trial. Methods and Materials: Multileaf collimator tracking was implemented for 15 patients in a prostate cancer radiation therapy trial; in total, 513 treatment fractions were delivered. During each treatment fraction, the prostate trajectory and treatment MLC positions were collected. These data were used as input for dose reconstruction (multiple isocenter shift method) to calculate the treated dose (with MLC tracking) and the dose that would have been delivered had MLC tracking not been applied (without MLC tracking). The percentage difference from planned for target and normal tissue dose-volume points were calculated. The hypothesis was tested for each dose-volume value via analysis of variance using the F test. Results: Of the 513 fractions delivered, 475 (93%) were suitable for analysis. The mean difference and standard deviation between the planned and treated MLC tracking doses and the planned and without-MLC tracking doses for all 475 fractions were, respectively, PTV D{sub 99%} −0.8% ± 1.1% versus −2.1% ± 2.7%; CTV D{sub 99%} −0.6% ± 0.8% versus −0.6% ± 1.1%; rectum V{sub 65%} 1.6% ± 7.9% versus −1.2% ± 18%; and bladder V{sub 65%} 0.5% ± 4.4% versus −0.0% ± 9.2% (P<.001 for all dose-volume results). Conclusion: This study shows that MLC tracking improves the consistency between the planned and delivered doses compared with the modeled doses without MLC tracking. The implications of this finding are potentially improved patient outcomes, as well as more reliable dose-volume data for radiobiological parameter determination.

  10. Radiation dose estimates for radiopharmaceuticals

    SciTech Connect

    Stabin, M.G.; Stubbs, J.B.; Toohey, R.E.

    1996-04-01

    Tables of radiation dose estimates based on the Cristy-Eckerman adult male phantom are provided for a number of radiopharmaceuticals commonly used in nuclear medicine. Radiation dose estimates are listed for all major source organs, and several other organs of interest. The dose estimates were calculated using the MIRD Technique as implemented in the MIRDOSE3 computer code, developed by the Oak Ridge Institute for Science and Education, Radiation Internal Dose Information Center. In this code, residence times for source organs are used with decay data from the MIRD Radionuclide Data and Decay Schemes to produce estimates of radiation dose to organs of standardized phantoms representing individuals of different ages. The adult male phantom of the Cristy-Eckerman phantom series is different from the MIRD 5, or Reference Man phantom in several aspects, the most important of which is the difference in the masses and absorbed fractions for the active (red) marrow. The absorbed fractions for flow energy photons striking the marrow are also different. Other minor differences exist, but are not likely to significantly affect dose estimates calculated with the two phantoms. Assumptions which support each of the dose estimates appears at the bottom of the table of estimates for a given radiopharmaceutical. In most cases, the model kinetics or organ residence times are explicitly given. The results presented here can easily be extended to include other radiopharmaceuticals or phantoms.

  11. 60Co contamination in recycled steel resulting in elevated civilian radiation doses: causes and challenges.

    PubMed

    Chang, W P; Chan, C C; Wang, J D

    1997-09-01

    Since late 1992, more than 100 building complexes containing public and private schools and nearly 1,000 apartments have been identified in Taiwan with elevated levels of gamma-radiation from construction steel contaminated with 60Co. Due to improper handling of 60Co contaminated scrap steel in late 1982 and 1983, contaminated construction materials have been widely distributed throughout the country. These contaminated construction materials have generated elevated radiation exposures to members of the public in Taiwan. As of early 1996, more than 4,000 people, including young students, have been identified as receiving more than 1 mSv y(-1) above the local background for up to 12 y. This report provides a detailed discussion of the sources of the 60Co contamination in construction steel, its discovery in the building complexes, and preliminary evaluation and remediation activities. PMID:9287087

  12. Atmospheric radiation flight dose rates

    NASA Astrophysics Data System (ADS)

    Tobiska, W. K.

    2015-12-01

    Space weather's effects upon the near-Earth environment are due to dynamic changes in the energy transfer processes from the Sun's photons, particles, and fields. Of the domains that are affected by space weather, the coupling between the solar and galactic high-energy particles, the magnetosphere, and atmospheric regions can significantly affect humans and our technology as a result of radiation exposure. Space Environment Technologies (SET) has been conducting space weather observations of the atmospheric radiation environment at aviation altitudes that will eventually be transitioned into air traffic management operations. The Automated Radiation Measurements for Aerospace Safety (ARMAS) system and Upper-atmospheric Space and Earth Weather eXperiment (USEWX) both are providing dose rate measurements. Both activities are under the ARMAS goal of providing the "weather" of the radiation environment to improve aircraft crew and passenger safety. Over 5-dozen ARMAS and USEWX flights have successfully demonstrated the operation of a micro dosimeter on commercial aviation altitude aircraft that captures the real-time radiation environment resulting from Galactic Cosmic Rays and Solar Energetic Particles. The real-time radiation exposure is computed as an effective dose rate (body-averaged over the radiative-sensitive organs and tissues in units of microsieverts per hour); total ionizing dose is captured on the aircraft, downlinked in real-time, processed on the ground into effective dose rates, compared with NASA's Langley Research Center (LaRC) most recent Nowcast of Atmospheric Ionizing Radiation System (NAIRAS) global radiation climatology model runs, and then made available to end users via the web and smart phone apps. Flight altitudes now exceed 60,000 ft. and extend above commercial aviation altitudes into the stratosphere. In this presentation we describe recent ARMAS and USEWX results.

  13. High-dose radiation improved local tumor control and overall survival in patients with inoperable/unresectable non-small-cell lung cancer: Long-term results of a radiation dose escalation study

    SciTech Connect

    Kong, F.-M. . E-mail: Fengkong@med.umich.edu; Haken, Randall K. ten; Schipper, Matthew J.; Sullivan, Molly A.; Chen, Ming; Lopez, Carlos; Kalemkerian, Gregory P.; Hayman, James A.

    2005-10-01

    Purpose: To determine whether high-dose radiation leads to improved outcomes in patients with non-small-cell lung cancer (NSCLC). Methods and Materials: This analysis included 106 patients with newly diagnosed or recurrent Stages I-III NSCLC, treated with 63-103 Gy in 2.1-Gy fractions, using three-dimensional conformal radiation therapy (3D-CRT) per a dose escalation trial. Targets included the primary tumor and any lymph nodes {>=}1 cm, without intentionally including negative nodal regions. Nineteen percent of patients (20/106) received neoadjuvant chemotherapy. Patient, tumor, and treatment factors were evaluated for association with outcomes. Estimated median follow-up was 8.5 years. Results: Median survival was 19 months, and 5-year overall survival (OS) was 13%. Multivariate analysis revealed weight loss (p = 0.011) and radiation dose (p = 0.0006) were significant predictors for OS. The 5-year OS was 4%, 22%, and 28% for patients receiving 63-69, 74-84, and 92-103 Gy, respectively. Although presence of nodal disease was negatively associated with locoregional control under univariate analysis, radiation dose was the only significant predictor when multiple variables were included (p = 0.015). The 5-year control rate was 12%, 35%, and 49% for 63-69, 74-84, and 92-103 Gy, respectively. Conclusions: Higher dose radiation is associated with improved outcomes in patients with NSCLC treated in the range of 63-103 Gy.

  14. Enhancement of T cell responses as a result of synergy between lower doses of radiation and T cell stimulation.

    PubMed

    Spary, Lisa K; Al-Taei, Saly; Salimu, Josephine; Cook, Alexander D; Ager, Ann; Watson, H Angharad; Clayton, Aled; Staffurth, John; Mason, Malcolm D; Tabi, Zsuzsanna

    2014-04-01

    As a side effect of cancer radiotherapy, immune cells receive varying doses of radiation. Whereas high doses of radiation (>10 Gy) can lead to lymphopenia, lower radiation doses (2-4 Gy) represent a valid treatment option in some hematological cancers, triggering clinically relevant immunological changes. Based on our earlier observations, we hypothesized that lower radiation doses have a direct positive effect on T cells. In this study, we show that 0.6-2.4 Gy radiation enhances proliferation and IFN-γ production of PBMC or purified T cells induced by stimulation via the TCR. Radiation with 1.2 Gy also lowered T cell activation threshold and broadened the Th1 cytokine profile. Although radiation alone did not activate T cells, when followed by TCR stimulation, ERK1/2 and Akt phosphorylation increased above that induced by stimulation alone. These changes were followed by an early increase in glucose uptake. Naive (CD45RA(+)) or memory (CD45RA(-)) T cell responses to stimulation were boosted at similar rates by radiation. Whereas increased Ag-specific cytotoxic activity of a CD8(+) T cell line manifested in a 4-h assay (10-20% increase), highly significant (5- to 10-fold) differences in cytokine production were detected in 6-d Ag-stimulation assays of PBMC, probably as a net outcome of death of nonstimulated and enhanced response of Ag-stimulated T cells. T cells from patients receiving pelvic radiation (2.2-2.75 Gy) also displayed increased cytokine production when stimulated in vitro. We report in this study enhanced T cell function induced by synergistic radiation treatment, with potential physiological significance in a wide range of T cell responses. PMID:24600032

  15. Temporal and spatial evolution of the solar energetic particle event on 20 January 2005 and resulting radiation doses in aviation

    NASA Astrophysics Data System (ADS)

    Matthiä, D.; Heber, B.; Reitz, G.; Meier, M.; Sihver, L.; Berger, T.; Herbst, K.

    2009-08-01

    The solar energetic particle event on 20 January 2005 was one of the largest ground level events ever observed. Neutron monitor stations in the Antarctic recorded count rate increases of several thousand percent caused by secondary energetic particles, and it took more than 36 h to return to background level. Such huge increases in high energetic solar cosmic radiation on the ground are obviously accompanied by considerable changes in the radiation environment at aviation altitudes. Measurements of 28 neutron monitor stations were used in this work to numerically approximate the primary solar proton spectra during the first 12 h of the event by minimizing the differences between measurements and the results of Monte-Carlo calculated count rate increases. The primary spectrum of solar energetic protons was approximated by a power law in rigidity and a linear angular distribution. The incoming direction of the solar energetic particles was determined and compared to the interplanetary magnetic field direction during the event. The effects on the radiation exposure at altitudes of about 12 km during that time were estimated to range from none at low latitudes up to almost 2 mSv/h for a very short time in the Antarctic region and about 0.1 mSv/h at high latitudes on the Northern Hemisphere. After 12 h, dose rates were still increased by 50% at latitudes above 60° whereas no increases at all occurred at latitudes below 40° during the whole event.

  16. Recommendations to the Technical Steering Panel regarding approach for estimating individual radiation doses resulting from releases of radionuclides to the Columbia River

    SciTech Connect

    Napier, B.A.; Brothers, A.J.

    1992-07-01

    At the direction of the Technical Steering Panel (TSP) of the Hanford Environmental Dose Reconstruction (HEDR) Project, Battelle staff have reviewed and analyzed available data regarding possible historical radiation doses to individuals resulting from radionuclide releases to the Columbia River. The objective of this review was to recommend to the TSP the spatial and temporal scope and level of effort on Columbia River work to most effectively extend work performed in Phase I of the project (PNL 1991a, PNL 1991b) to meet the project objectives. A number of options were analyzed. Four stretches of the Columbia River and adjacent Pacific coastal waters were defined and investigated for four time periods. Radiation doses arising from ten potentially major exposure pathways were evaluated for each of the time/location combinations, and several alternative methods were defined for estimating the doses from each pathway. Preliminary cost estimates were also developed for implementing dose estimation activities for each of the possible combinations.

  17. Recommendations to the Technical Steering Panel regarding approach for estimating individual radiation doses resulting from releases of radionuclides to the Columbia River. Volume 1, Recommendations

    SciTech Connect

    Napier, B.A.; Brothers, A.J.

    1992-07-01

    At the direction of the Technical Steering Panel (TSP) of the Hanford Environmental Dose Reconstruction (HEDR) Project, Battelle staff have reviewed and analyzed available data regarding possible historical radiation doses to individuals resulting from radionuclide releases to the Columbia River. The objective of this review was to recommend to the TSP the spatial and temporal scope and level of effort on Columbia River work to most effectively extend work performed in Phase I of the project (PNL 1991a, PNL 1991b) to meet the project objectives. A number of options were analyzed. Four stretches of the Columbia River and adjacent Pacific coastal waters were defined and investigated for four time periods. Radiation doses arising from ten potentially major exposure pathways were evaluated for each of the time/location combinations, and several alternative methods were defined for estimating the doses from each pathway. Preliminary cost estimates were also developed for implementing dose estimation activities for each of the possible combinations.

  18. Randomized, Multicenter Trial on the Effect of Radiation Therapy on Plantar Fasciitis (Painful Heel Spur) Comparing a Standard Dose With a Very Low Dose: Mature Results After 12 Months' Follow-Up

    SciTech Connect

    Niewald, Marcus; Micke, Oliver; Graeber, Stefan; Schaefer, Vera; Scheid, Christine; Fleckenstein, Jochen; Licht, Norbert; Ruebe, Christian

    2012-11-15

    Purpose: To conduct a randomized trial of radiation therapy for painful heel spur, comparing a standard dose with a very low dose. Methods and Materials: Sixty-six patients were randomized to receive radiation therapy either with a total dose of 6.0 Gy applied in 6 fractions of 1.0 Gy twice weekly (standard dose) or with a total dose of 0.6 Gy applied in 6 fractions of 0.1 Gy twice weekly (low dose). In all patients lateral opposing 4- to 6-MV photon beams were used. The results were measured using a visual analogue scale, the Calcaneodynia score, and the SF12 health survey. The fundamental phase of the study ended after 3 months, and the follow-up was continued up to 1 year. Patients with insufficient pain relief after 3 months were offered reirradiation with the standard dosage at any time afterward. Results: Of 66 patients, 4 were excluded because of withdrawal of consent or screening failures. After 3 months the results in the standard arm were highly significantly superior compared with those in the low-dose arm (visual analogue scale, P=.001; Calcaneodynia score, P=.027; SF12, P=.045). The accrual of patients was stopped at this point. Further evaluation after 12 months' follow-up showed the following results: (1) highly significant fewer patients were reirradiated in the standard arm compared with the low-dose arm (P<.001); (2) the results of patients in the low-dose arm who were reirradiated were identical to those in the standard arm not reirradiated (reirradiation as a salvage therapy if the lower dose was ineffective); (3) patients experiencing a favorable result after 3 months showed this even after 12 months, and some results even improved further between 3 and 12 months. Conclusions: This study confirms the superior analgesic effect of radiation therapy with 6-Gy doses on painful heel spur even for a longer time period of at least 1 year.

  19. Patient Radiation Doses in Interventional Cardiology Procedures

    PubMed Central

    Pantos, Ioannis; Patatoukas, Georgios; Katritsis, Demosthenes G; Efstathopoulos, Efstathios

    2009-01-01

    Interventional cardiology procedures result in substantial patient radiation doses due to prolonged fluoroscopy time and radiographic exposure. The procedures that are most frequently performed are coronary angiography, percutaneous coronary interventions, diagnostic electrophysiology studies and radiofrequency catheter ablation. Patient radiation dose in these procedures can be assessed either by measurements on a series of patients in real clinical practice or measurements using patient-equivalent phantoms. In this article we review the derived doses at non-pediatric patients from 72 relevant studies published during the last 22 years in international scientific literature. Published results indicate that patient radiation doses vary widely among the different interventional cardiology procedures but also among equivalent studies. Discrepancies of the derived results are patient-, procedure-, physician-, and fluoroscopic equipmentrelated. Nevertheless, interventional cardiology procedures can subject patients to considerable radiation doses. Efforts to minimize patient exposure should always be undertaken. PMID:20066141

  20. Radiation: Doses, Effects, Risks.

    ERIC Educational Resources Information Center

    Lean, Geoffrey, Ed.

    Few scientific issues arouse as much public controversy as the effects of radiation. This booklet is an attempt to summarize what is known about radiation and provide a basis for further discussion and debate. The first four chapters of the booklet are based on the most recent reports to the United Nations' General Assembly by the United Nations…

  1. Occupational radiation doses during interventional procedures

    NASA Astrophysics Data System (ADS)

    Nuraeni, N.; Hiswara, E.; Kartikasari, D.; Waris, A.; Haryanto, F.

    2016-03-01

    Digital subtraction angiography (DSA) is a type of fluoroscopy technique used in interventional radiology to clearly visualize blood vessels in a bony or dense soft tissue environment. The use of DSA procedures has been increased quite significantly in the Radiology departments in various cities in Indonesia. Various reports showed that both patients and medical staff received a noticeable radiation dose during the course of this procedure. A study had been carried out to measure these doses among interventionalist, nurse and radiographer. The results show that the interventionalist and the nurse, who stood quite close to the X-ray beams compared with the radiographer, received radiation higher than the others. The results also showed that the radiation dose received by medical staff were var depending upon the duration and their position against the X-ray beams. Compared tothe dose limits, however, the radiation dose received by all these three medical staff were still lower than the limits.

  2. Radiation dose rate meter

    SciTech Connect

    Kronenberg, S.; Siebentritt, C.R.

    1981-07-28

    A combined dose rate meter and charger unit therefor which does not require the use of batteries but on the other hand produces a charging potential by means of a piezoelectric cylinder which is struck by a manually triggered hammer mechanism. A tubular type electrometer is mounted in a portable housing which additionally includes a geiger-muller (Gm) counter tube and electronic circuitry coupled to the electrometer for providing multi-mode operation. In one mode of operation, an rc circuit of predetermined time constant is connected to a storage capacitor which serves as a timed power source for the gm tube, providing a measurement in terms of dose rate which is indicated by the electrometer. In another mode, the electrometer indicates individual counts.

  3. EXOMARS IRAS (DOSE) radiation measurements.

    NASA Astrophysics Data System (ADS)

    Federico, C.; Di Lellis, A. M.; Fonte, S.; Pauselli, C.; Reitz, G.; Beaujean, R.

    The characterization and the study of the radiations on their interaction with organic matter is of great interest in view of the human exploration on Mars. The Ionizing RAdiation Sensor (IRAS) selected in the frame of the ExoMars/Pasteur ESA mission is a lightweight particle spectrometer combining various techniques of radiation detection in space. It characterizes the first time the radiation environment on the Mars surface, and provide dose and dose equivalent rates as precursor information absolutely necessary to develop ways to mitigate the radiation risks for future human exploration on Mars. The Martian radiation levels are much higher than those found on Earth and they are relatively low for space. Measurements on the surface will show if they are similar or not to those seen in orbit (modified by the presence of ``albedo'' neutrons produced in the regolith and by the thin Martian atmosphere). IRAS consists of a telescope based on segmented silicon detectors of about 40\\userk\\milli\\metre\\user;k diameter and 300\\user;k\\micro\\metre\\user;k thickness, a segmented organic scintillator, and of a thermoluminescence dosimeter. The telescope will continuously monitor temporal variation of the particle count rate, the dose rate, particle and LET (Linear Energy Transfer) spectra. Tissue equivalent BC430 scintillator material will be used to measure the neutron dose. Neutrons are selected by a criteria requiring no signal in the anti-coincidence. Last, the passive thermoluminescence dosimeter, based on LiF:Mg detectors, regardless the on board operation timing, will measure the total dose accumulated during the exposure period and due to beta and gamma radiation, with a responsivity very close to that of a human tissue.

  4. [Results of statistical analysis of the dynamics of ionizing radiation dose fields in the service module of the International Space Station in 2000-2012].

    PubMed

    Mitrikas, V G

    2014-01-01

    The on-going 24th solar cycle (SC) is distinguished from the previous ones by low activity. On the contrary, levels of proton fluxes from galactic cosmic rays (GCR) are high, which increases the proton flow striking the Earth's radiation belts (ERB). Therefore, at present the absorbed dose from ERB protons should be calculated with consideration of the tangible increase of protons intensity built into the model descriptions based on experimental measurements during the minimum between cycles 19 and 20, and the cycle 21 maximum. The absorbed dose from GCR and ERB protons copies galactic protons dynamics, while the ERB electrons dose copies SC dynamics. The major factors that determine the absorbed dose value are SC phase, ISS orbital altitude and shielding of the dosimeter readings of which are used in analysis. The paper presents the results of dynamic analysis of absorbed doses measured by a variety of dosimeters, namely, R-16 (2 ionization chambers), DB8-1, DB8-2, DB8-3, DB8-4 as a function of ISS orbit altitude and SC phase. The existence of annual variation in the absorbed dose dynamics has been confirmed; several additional variations with the periods of 17 and 52 months have been detected. Modulation of absorbed dose variations by the SC and GCR amplitudes has been demonstrated. PMID:25035897

  5. Low-dose radiation exposure and carcinogenesis.

    PubMed

    Suzuki, Keiji; Yamashita, Shunichi

    2012-07-01

    Absorption of energy from ionizing radiation by the genetic material in the cell leads to damage to DNA, which in turn leads to cell death, chromosome aberrations and gene mutations. While early or deterministic effects result from organ and tissue damage caused by cell killing, latter two are considered to be involved in the initial events that lead to the development of cancer. Epidemiological studies have demonstrated the dose-response relationships for cancer induction and quantitative evaluations of cancer risk following exposure to moderate to high doses of low-linear energy transfer radiation. A linear, no-threshold model has been applied to assessment of the risks resulting from exposure to moderate and high doses of ionizing radiation; however, a statistically significant increase has hardly been described for radiation doses below 100 mSv. This review summarizes our current knowledge of the physical and biological features of low-dose radiation and discusses the possibilities of induction of cancer by low-dose radiation. PMID:22641644

  6. Dose specification for radiation therapy: dose to water or dose to medium?

    PubMed

    Ma, C-M; Li, Jinsheng

    2011-05-21

    The Monte Carlo method enables accurate dose calculation for radiation therapy treatment planning and has been implemented in some commercial treatment planning systems. Unlike conventional dose calculation algorithms that provide patient dose information in terms of dose to water with variable electron density, the Monte Carlo method calculates the energy deposition in different media and expresses dose to a medium. This paper discusses the differences in dose calculated using water with different electron densities and that calculated for different biological media and the clinical issues on dose specification including dose prescription and plan evaluation using dose to water and dose to medium. We will demonstrate that conventional photon dose calculation algorithms compute doses similar to those simulated by Monte Carlo using water with different electron densities, which are close (<4% differences) to doses to media but significantly different (up to 11%) from doses to water converted from doses to media following American Association of Physicists in Medicine (AAPM) Task Group 105 recommendations. Our results suggest that for consistency with previous radiation therapy experience Monte Carlo photon algorithms report dose to medium for radiotherapy dose prescription, treatment plan evaluation and treatment outcome analysis. PMID:21508447

  7. The Dose Response Relationship for Radiation Carcinogenesis

    NASA Astrophysics Data System (ADS)

    Hall, Eric

    2008-03-01

    case of radiation oncology, modern innovations such as Intensity Modulated Radiation Oncology or Proton Therapy both result in a substantial total-body dose to the patient, which must result in an increased incidence of second cancers. The technology exists to reduce these total body doses and the problem needs to be addressed.

  8. Ultraviolet radiation cataract: dose dependence

    NASA Astrophysics Data System (ADS)

    Soderberg, Per G.; Loefgren, Stefan

    1994-07-01

    Current safety limits for cataract development after acute exposure to ultraviolet radiation (UVR) are based on experiments analyzing experimental data with a quantal, effect-no effect, dose-response model. The present study showed that intensity of forward light scattering is better described with a continuous dose-response model. It was found that 3, 30 and 300 kJ/m2UVR300nm induces increased light scattering within 6 h. For all three doses the intensity of forward light scattering was constant after 6 h. The intensity of forward light scattering was proportional to the log dose of UVR300nm. There was a slight increase of the intensity of forward light scattering on the contralateral side in animals that received 300 kJ/m2. Altogether 72 Sprague-Dawley male rats were included. Half of the rats were exposed in vivo on one side to UVR300nm. The other half was kept as a control group, receiving the same treatment as exposed rats but without delivery of UVR300nm to the eye. Subgroups of the rats received either of the three doses. Rats were sacrificed at varying intervals after the exposure. The lenses were extracted and the forward light scattering was estimated. It is concluded that intensity of forward light scattering in the lens after exposure to UVR300nm should be described with a continuous dose-reponse model.

  9. Pediatric CT: Strategies to Lower Radiation Dose

    PubMed Central

    Zacharias, Claudia; Alessio, Adam M.; Otto, Randolph K.; Iyer, Ramesh S.; Philips, Grace S.; Swanson, Jonathan O.; Thapa, Mahesh M.

    2016-01-01

    OBJECTIVE The introduction of MDCT has increased the utilization of CT in pediatric radiology along with concerns for radiation sequelae. This article reviews general principles of lowering radiation dose, the basic physics that impact radiation dose, and specific CT integrated dose-reduction tools focused on the pediatric population. CONCLUSION The goal of this article is to provide a comprehensive review of the recent literature regarding CT dose reduction methods, their limitations, and an outlook on future developments with a focus on the pediatric population. The discussion will initially focus on general considerations that lead to radiation dose reduction, followed by specific technical features that influence the radiation dose. PMID:23617474

  10. Radiation Leukemogenesis at Low Dose Rates

    SciTech Connect

    Weil, Michael; Ullrich, Robert

    2013-09-25

    The major goals of this program were to study the efficacy of low dose rate radiation exposures for the induction of acute myeloid leukemia (AML) and to characterize the leukemias that are caused by radiation exposures at low dose rate. An irradiator facility was designed and constructed that allows large numbers of mice to be irradiated at low dose rates for protracted periods (up to their life span). To the best of our knowledge this facility is unique in the US and it was subsequently used to study radioprotectors being developed for radiological defense (PLoS One. 7(3), e33044, 2012) and is currently being used to study the role of genetic background in susceptibility to radiation-induced lung cancer. One result of the irradiation was expected; low dose rate exposures are ineffective in inducing AML. However, another result was completely unexpected; the irradiated mice had a very high incidence of hepatocellular carcinoma (HCC), approximately 50%. It was unexpected because acute exposures are ineffective in increasing HCC incidence above background. This is a potential important finding for setting exposure limits because it supports the concept of an 'inverse dose rate effect' for some tumor types. That is, for the development of some tumor types low dose rate exposures carry greater risks than acute exposures.

  11. Epigenomic Adaptation to Low Dose Radiation

    SciTech Connect

    Gould, Michael N.

    2015-06-30

    The overall hypothesis of this grant application is that the adaptive responses elicited by low dose ionizing radiation (LDIR) result in part from heritable DNA methylation changes in the epigenome. In the final budget period at the University of Wisconsin-Madison, we will specifically address this hypothesis by determining if the epigenetically labile, differentially methylated regions (DMRs) that regulate parental-specific expression of imprinted genes are deregulated in agouti mice by low dose radiation exposure during gestation. This information is particularly important to ascertain given the 1) increased human exposure to medical sources of radiation; 2) increased number of people predicted to live and work in space; and 3) enhanced citizen concern about radiation exposure from nuclear power plant accidents and terrorist ‘dirty bombs.’

  12. Dose levels of the occupational radiation exposures in Poland based on results from the accredited dosimetry service at the IFJ PAN, Krakow.

    PubMed

    Budzanowski, Maciej; Kopeć, Renata; Obryk, Barbara; Olko, Paweł

    2011-03-01

    Individual dosimetry service based on thermoluminescence (TLD) detectors has started its activity at the Institute of Nuclear Physics (IFJ) in Krakow in 1965. In 2002, the new Laboratory of Individual and Environment Dosimetry (Polish acronym LADIS) was established and underwent the accreditation according to the EN-PN-ISO/IEC 17025 standard. Nowadays, the service is based on the worldwide known standard thermoluminescent detectors MTS-N (LiF:Mg,Ti) and MCP-N (LiF:Mg,Cu,P), developed at IFJ, processed in automatic thermoluminescent DOSACUS or RE2000 (Rados Oy, Finland) readers. Laboratory provides individual monitoring in terms of personal dose equivalent H(p)(10) and H(p)(0.07) in photon and neutron fields, over the range from 0.1 mSv to 1 Sv, and environmental dosimetry in terms of air kerma K(a) over the range from 30 μGy to 1 Gy and also ambient dose equivalent H*(10) over the range from 30 μSv to 1 Sv. Dosimetric service is currently performed for ca. 3200 institutions from Poland and abroad, monitored on quarterly and monthly basis. The goal of this paper is to identify the main activities leading to the highest radiation exposures in Poland. The paper presents the results of statistical evaluation of ∼ 100,000 quarterly H(p)(10) and K(a) measurements performed between 2002 and 2009. Sixty-five per cent up to 90 % of all individual doses in Poland are on the level of natural radiation background. The dose levels between 0.1 and 5 mSv per quarter are the most frequent in nuclear medicine, veterinary and industrial radiography sectors. PMID:21183549

  13. Radiation-induced genomic instability: radiation quality and dose response

    NASA Technical Reports Server (NTRS)

    Smith, Leslie E.; Nagar, Shruti; Kim, Grace J.; Morgan, William F.

    2003-01-01

    Genomic instability is a term used to describe a phenomenon that results in the accumulation of multiple changes required to convert a stable genome of a normal cell to an unstable genome characteristic of a tumor. There has been considerable recent debate concerning the importance of genomic instability in human cancer and its temporal occurrence in the carcinogenic process. Radiation is capable of inducing genomic instability in mammalian cells and instability is thought to be the driving force responsible for radiation carcinogenesis. Genomic instability is characterized by a large collection of diverse endpoints that include large-scale chromosomal rearrangements and aberrations, amplification of genetic material, aneuploidy, micronucleus formation, microsatellite instability, and gene mutation. The capacity of radiation to induce genomic instability depends to a large extent on radiation quality or linear energy transfer (LET) and dose. There appears to be a low dose threshold effect with low LET, beyond which no additional genomic instability is induced. Low doses of both high and low LET radiation are capable of inducing this phenomenon. This report reviews data concerning dose rate effects of high and low LET radiation and their capacity to induce genomic instability assayed by chromosomal aberrations, delayed lethal mutations, micronuclei and apoptosis.

  14. Radiation dose measurements in coronary CT angiography

    PubMed Central

    Sabarudin, Akmal; Sun, Zhonghua

    2013-01-01

    Coronary computed tomography (CT) angiography is associated with high radiation dose and this has raised serious concerns in the literature. Awareness of various parameters for dose estimates and measurements of coronary CT angiography plays an important role in increasing our understanding of the radiation exposure to patients, thus, contributing to the implementation of dose-saving strategies. This article provides an overview of the radiation dose quantity and its measurement during coronary CT angiography procedures. PMID:24392190

  15. Risk of Late Toxicity in Men Receiving Dose-Escalated Hypofractionated Intensity Modulated Prostate Radiation Therapy: Results From a Randomized Trial

    SciTech Connect

    Hoffman, Karen E. Voong, K. Ranh; Pugh, Thomas J.; Skinner, Heath; Levy, Lawrence B.; Takiar, Vinita; Choi, Seungtaek; Du, Weiliang; Frank, Steven J.; Johnson, Jennifer; Kanke, James; Kudchadker, Rajat J.; Lee, Andrew K.; Mahmood, Usama; McGuire, Sean E.; Kuban, Deborah A.

    2014-04-01

    Objective: To report late toxicity outcomes from a randomized trial comparing conventional and hypofractionated prostate radiation therapy and to identify dosimetric and clinical parameters associated with late toxicity after hypofractionated treatment. Methods and Materials: Men with localized prostate cancer were enrolled in a trial that randomized men to either conventionally fractionated intensity modulated radiation therapy (CIMRT, 75.6 Gy in 1.8-Gy fractions) or to dose-escalated hypofractionated IMRT (HIMRT, 72 Gy in 2.4-Gy fractions). Late (≥90 days after completion of radiation therapy) genitourinary (GU) and gastrointestinal (GI) toxicity were prospectively evaluated and scored according to modified Radiation Therapy Oncology Group criteria. Results: 101 men received CIMRT and 102 men received HIMRT. The median age was 68, and the median follow-up time was 6.0 years. Twenty-eight percent had low-risk, 71% had intermediate-risk, and 1% had high-risk disease. There was no difference in late GU toxicity in men treated with CIMRT and HIMRT. The actuarial 5-year grade ≥2 GU toxicity was 16.5% after CIMRT and 15.8% after HIMRT (P=.97). There was a nonsignificant numeric increase in late GI toxicity in men treated with HIMRT compared with men treated with CIMRT. The actuarial 5-year grade ≥2 GI toxicity was 5.1% after CIMRT and 10.0% after HIMRT (P=.11). In men receiving HIMRT, the proportion of rectum receiving 36.9 Gy, 46.2 Gy, 64.6 Gy, and 73.9 Gy was associated with the development of late GI toxicity (P<.05). The 5-year actuarial grade ≥2 GI toxicity was 27.3% in men with R64.6Gy ≥ 20% but only 6.0% in men with R64.6Gy < 20% (P=.016). Conclusions: Dose-escalated IMRT using a moderate hypofractionation regimen (72 Gy in 2.4-Gy fractions) can be delivered safely with limited grade 2 or 3 late toxicity. Minimizing the proportion of rectum that receives moderate and high dose decreases the risk of late rectal toxicity after this

  16. [Evaluation of radiation doses in mammography].

    PubMed

    Lee, S K; Hwang, S K; Lee, L N; Lou, G C; Wang, C A; Hsu, W J

    1993-03-01

    A dedicated X-ray mammography was introduced to our hospital from 1987 and an imaging receptor of xeroradiography was applied. We reported previously that the average air exposure was 0.79R and that the absorption dose of skin was 1.00 rad. These data are similar to literature reports. Screen-film mammography was introduced recently. To select the best breast imaging and the least radiation exposure, diverse methods were investigated. A dosimetry (Capintec model 192) and a PS-033 parallel ionization chamber were applied to compare the absorption dose on polystyrene phantom between various exposure factors, the application of breast clamp and the size of exposure field. Retrospective estimation of the radiation dose was obtained from the exposure factors of previous mammography since July, 1990 to May, 1992. There were 1035 xeromammographic examinations and 358 examinations with medium-speed screen-film mammography. Another 61 craniocaudal and 96 mediolateral projections with high-speed screen-film mammography were recruited during the recent two months. An ionization chamber (Exradin, Shonka-Wyckoff A5) with an electrometer (Keithley 617) wer selected to obtain the dose equivalent from air exposure between selected exposure factors. The radiation dose of mammography is linearly correlated with voltage/kV and current/mAs. The application of a breast clump reduces 10% of the skin dose. The average exposure factors of xeromammography are 45.6 kV, 163.5 mAs. These results remain the same as in our previous report. Xeromammography has a greater exposure to air, estimated average glandular dose and absorbed dose than screen-film mammography. The mean exposure factor of rapid screen-film mammography gains half the value of medium screen-film mammography, ie. 26.6 kV, 87.0 mAs vs. 26.0 kV, 164.5 mAs.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8490794

  17. Radiation Doses to Members of the U.S. Population from Ubiquitous Radionuclides in the Body: Part 3, Results, Variability, and Uncertainty

    SciTech Connect

    Watson, David J.; Strom, Daniel J.

    2011-02-25

    This paper is part three of a three-part series investigating annual effective doses to residents of the United States from intakes of ubiquitous radionuclides, including radionuclides occurring naturally, radionuclides whose concentrations are technologically enhanced, and anthropogenic radionuclides. The radionuclides of interest are the 238U series (14 nuclides), the actinium series (headed by 235U; 11 nuclides), and the 232Th series (11 nuclides); primordial radionuclides 87Rb and 40K; cosmogenic and fallout radionuclides 14C and 3H; and purely anthropogenic radionuclides 137Cs-137mBa, 129I and 90Sr-90Y. This series of papers explicitly excludes intakes from inhaling 222Rn, 220Rn, and their short-lived decay products; it also excludes intakes of radionuclides in occupational and medical settings. Part one reviewed, summarized, characterized, and grouped all published and some unpublished data for U.S. residents on ubiquitous radionuclide concentrations in tissues and organs. Part two described the methods used to organize the data collected in part one and segregate it into the ages and genders defined by the study, imputed missing values from the existing data, apportioned activity in bone, and imputed activity in hollow organ contents and the remainder of the body. This paper estimates equivalent doses to target tissues from source regions and maps target tissues to lists of tissues with International Commission on Radiation Protection (ICRP) tissue-weighting factors or to surrogate tissue regions when there is no direct match. Effective doses, using ICRP tissue-weighting factors recommended in 1977, 1990, and 2007, are then calculated, and an upper bound of variability of the effective dose is estimated by calculating the average coefficients of variation (CV), assuming all variance is due to variability. Most of the data were for adult males, whose average annual effective dose is estimated to be 337 μSv (CV = 0.65, geometric mean = 283 μSv, geometric

  18. SU-C-18C-06: Radiation Dose Reduction in Body Interventional Radiology: Clinical Results Utilizing a New Imaging Acquisition and Processing Platform

    SciTech Connect

    Kohlbrenner, R; Kolli, KP; Taylor, A; Kohi, M; Fidelman, N; LaBerge, J; Kerlan, R; Gould, R

    2014-06-01

    Purpose: To quantify the patient radiation dose reduction achieved during transarterial chemoembolization (TACE) procedures performed in a body interventional radiology suite equipped with the Philips Allura Clarity imaging acquisition and processing platform, compared to TACE procedures performed in the same suite equipped with the Philips Allura Xper platform. Methods: Total fluoroscopy time, cumulative dose area product, and cumulative air kerma were recorded for the first 25 TACE procedures performed to treat hepatocellular carcinoma (HCC) in a Philips body interventional radiology suite equipped with Philips Allura Clarity. The same data were collected for the prior 85 TACE procedures performed to treat HCC in the same suite equipped with Philips Allura Xper. Mean values from these cohorts were compared using two-tailed t tests. Results: Following installation of the Philips Allura Clarity platform, a 42.8% reduction in mean cumulative dose area product (3033.2 versus 1733.6 mGycm∧2, p < 0.0001) and a 31.2% reduction in mean cumulative air kerma (1445.4 versus 994.2 mGy, p < 0.001) was achieved compared to similar procedures performed in the same suite equipped with the Philips Allura Xper platform. Mean total fluoroscopy time was not significantly different between the two cohorts (1679.3 versus 1791.3 seconds, p = 0.41). Conclusion: This study demonstrates a significant patient radiation dose reduction during TACE procedures performed to treat HCC after a body interventional radiology suite was converted to the Philips Allura Clarity platform from the Philips Allura Xper platform. Future work will focus on evaluation of patient dose reduction in a larger cohort of patients across a broader range of procedures and in specific populations, including obese patients and pediatric patients, and comparison of image quality between the two platforms. Funding for this study was provided by Philips Healthcare, with 5% salary support provided to authors K. Pallav

  19. Hypofractionated High-Dose Radiation Therapy for Prostate Cancer: Long-Term Results of a Multi-Institutional Phase II Trial

    SciTech Connect

    Fonteyne, Valerie; Soete, Guy; Arcangeli, Stefano; De Neve, Wilfried; Rappe, Bernard; Storme, Guy; Strigari, Lidia; Arcangeli, Giorgio; De Meerleer, Gert

    2012-11-15

    Purpose: To report late gastrointestinal (GI) and genitourinary (GU) toxicity, biochemical and clinical outcomes, and overall survival after hypofractionated radiation therapy for prostate cancer (PC). Methods and Materials: Three institutions included 113 patients with T1 to T3N0M0 PC in a phase II study. Patients were treated with 56 Gy in 16 fractions over 4 weeks. Late toxicity was scored using Radiation Therapy Oncology Group/European Organization for Research and Treatment of Cancer criteria extended with additional symptoms. Biochemical outcome was reported according to the Phoenix definition for biochemical failure. Results: The incidence of late GI and GU toxicity was low. The 3-year actuarial risk of developing late GU and GI toxicity of grade {>=}2 was 13% and 8% respectively. Five-year biochemical non-evidence of disease (bNED) was 94%. Risk group, T stage, and deviation from planned hormone treatment were significant predictive factors for bNED. Deviation from hormone treatment remained significant in multivariate analysis. Five-year clinical non evidence of disease and overall survival was 95% and 91% respectively. No patient died from PC. Conclusions: Hypofractionated high-dose radiation therapy is a valuable treatment option for patients with PC, with excellent biochemical and clinical outcome and low toxicity.

  20. Radiation Dose Optimization For Critical Organs

    NASA Astrophysics Data System (ADS)

    Khodadadegan, Yasaman

    Ionizing radiation used in the patient diagnosis or therapy has negative effects on the patient body in short term and long term depending on the amount of exposure. More than 700,000 examinations are everyday performed on Interventional Radiology modalities, however; there is no patient-centric information available to the patient or the Quality Assurance for the amount of organ dose received. In this study, we are exploring the methodologies to systematically reduce the absorbed radiation dose in the Fluoroscopically Guided Interventional Radiology procedures. In the first part of this study, we developed a mathematical model which determines a set of geometry settings for the equipment and a level for the energy during a patient exam. The goal is to minimize the amount of absorbed dose in the critical organs while maintaining image quality required for the diagnosis. The model is a large-scale mixed integer program. We performed polyhedral analysis and derived several sets of strong inequalities to improve the computational speed and quality of the solution. Results present the amount of absorbed dose in the critical organ can be reduced up to 99% for a specific set of angles. In the second part, we apply an approximate gradient method to simultaneously optimize angle and table location while minimizing dose in the critical organs with respect to the image quality. In each iteration, we solve a sub-problem as a MIP to determine the radiation field size and corresponding X-ray tube energy. In the computational experiments, results show further reduction (up to 80%) of the absorbed dose in compare with previous method. Last, there are uncertainties in the medical procedures resulting imprecision of the absorbed dose. We propose a robust formulation to hedge from the worst case absorbed dose while ensuring feasibility. In this part, we investigate a robust approach for the organ motions within a radiology procedure. We minimize the absorbed dose for the critical

  1. Radiation doses to members of the U.S. population from ubiquitous radionuclides in the body: Part 3, results, variability, and uncertainty.

    PubMed

    Watson, David J; Strom, Daniel J

    2011-04-01

    ), assuming all variance is due to variability. Most of the data were for adult males, whose average effective dose rate is estimated to be 337 μSv y(-1) (CV = 0.65, geometric mean = 283 μSv y(-1), geometric standard deviation s(G) = 1.81) using 2007 ICRP tissue-weighting factors. This result is between the National Council on Radiation Protection and Measurements' 1987 estimate of 390 μSv y(-1) (using 1977 w(T)s) and its 2009 estimate of 285 μSv y(-1) (using 2007 w(T)s) and is higher than the United Nations Scientific Committee on the Effects of Atomic Radiation's 2000 estimate of 310 μSv y(-1) (using 1990 w(T)s). The methods and software developed for this project are sufficiently detailed and sufficiently general to be usable with autopsy data from any or all countries. PMID:21350346

  2. A Program for Calculating Radiation Dose Rates.

    Energy Science and Technology Software Center (ESTSC)

    1986-01-27

    Version 00 SMART calculates radiation dose rate at the center of the outer cask surface. It can be applied to determine the radiation dose rate on each cask if source conditions, characteristic function, and material conditions in the bottle regions are given. MANYCASK calculates radiation dose rate distribution in a space surrounded by many casks. If the dose rate on each cask surface can be measured, MANYCASK can be applied to predict dose spatial dosemore » rate distribution for any case of cask configuration.« less

  3. Single-Fraction High-Dose-Rate Brachytherapy and Hypofractionated External Beam Radiation Therapy in the Treatment of Intermediate-Risk Prostate Cancer - Long Term Results

    SciTech Connect

    Cury, Fabio L.; Duclos, Marie; Aprikian, Armen; Patrocinio, Horacio; Kassouf, Wassim; Shenouda, George; Faria, Sergio; David, Marc; Souhami, Luis

    2012-03-15

    Purpose: We present the long-term results of a cohort of patients with intermediate-risk prostate cancer (PC) treated with single-fraction high-dose-rate brachytherapy (HDRB) combined with hypofractionated external beam radiation therapy (HypoRT). Methods and Materials: Patients were treated exclusively with HDRB and HypoRT. HDRB delivered a dose of 10 Gy to the prostate surface and HypoRT consisted of 50 Gy delivered in 20 daily fractions. The first 121 consecutive patients with a minimum of 2 years posttreatment follow-up were assessed for toxicity and disease control. Results: The median follow-up was 65.2 months. No acute Grade III or higher toxicity was seen. Late Grade II gastrointestinal toxicity was seen in 9 patients (7.4%) and Grade III in 2 (1.6%). Late Grade III genitourinary toxicity was seen in 2 patients (1.6%). After a 24-month follow-up, a rebiopsy was offered to the first 58 consecutively treated patients, and 44 patients agreed with the procedure. Negative biopsies were found in 40 patients (91%). The 5-year biochemical relapse-free survival rate was 90.7% (95% CI, 84.5-96.9%), with 13 patients presenting biochemical failure. Among them, 9 were diagnosed with distant metastasis. Prostate cancer-specific and overall survival rates at 5 years were 100% and 98.8% (95% CI, 96.4-100%), respectively. Conclusion: The combination of HDRB and HypoRT is well tolerated, with acceptable toxicity rates. Furthermore, results from rebiopsies revealed an encouraging rate of local control. These results confirm that the use of conformal RT techniques, adapted to specific biological tumor characteristics, have the potential to improve the therapeutic ratio in intermediate-risk PC patients.

  4. Low-dose radiation epidemiology studies: status and issues.

    PubMed

    Shore, Roy E

    2009-11-01

    Although the Japanese atomic bomb study and radiotherapy studies have clearly documented cancer risks from high-dose radiation exposures, radiation risk assessment groups have long recognized that protracted or low exposures to low-linear energy transfer radiations are key radiation protection concerns because these are far more common than high-exposure scenarios. Epidemiologic studies of human populations with low-dose or low dose-rate exposures are one approach to addressing those concerns. A number of large studies of radiation workers (Chernobyl clean-up workers, U.S. and Chinese radiological technologists, and the 15-country worker study) or of persons exposed to environmental radiation at moderate to low levels (residents near Techa River, Semipalatinsk, Chernobyl, or nuclear facilities) have been conducted. A variety of studies of medical radiation exposures (multiple-fluoroscopy, diagnostic (131)I, scatter radiation doses from radiotherapy, etc.) also are of interest. Key results from these studies are summarized and compared with risk estimates from the Japanese atomic bomb study. Ideally, one would like the low-dose and low dose-rate studies to guide radiation risk estimation regarding the shape of the dose-response curve, DDREF (dose and dose-rate effectiveness factor), and risk at low doses. However, the degree to which low-dose studies can do so is subject to various limitations, especially those pertaining to dosimetric uncertainties and limited statistical power. The identification of individuals who are particularly susceptible to radiation cancer induction also is of high interest in terms of occupational and medical radiation protection. Several examples of studies of radiation-related cancer susceptibility are discussed, but none thus far have clearly identified radiation-susceptible genotypes. PMID:19820457

  5. Potential radiation doses from 1994 Hanford Operations

    SciTech Connect

    Soldat, J.K.; Antonio, E.J.

    1995-06-01

    This section of the 1994 Hanford Site Environmental Report summarizes the potential radiation doses to the public from releases originating at the Hanford Site. Members of the public are potentially exposed to low-levels of radiation from these effluents through a variety of pathways. The potential radiation doses to the public were calculated for the hypothetical MEI and for the general public residing within 80 km (50 mi) of the Hanford Site.

  6. A Phase I/II Radiation Dose Escalation Study With Concurrent Chemotherapy for Patients With Inoperable Stages I to III Non-Small-Cell Lung Cancer: Phase I Results of RTOG 0117

    SciTech Connect

    Bradley, Jeffrey D.; Moughan, Jennifer; Graham, Mary V.; Byhardt, Roger; Govindan, Ramaswamy; Fowler, Jack; Purdy, James A.; Michalski, Jeff M.; Gore, Elizabeth; Choy, Hak

    2010-06-01

    Purpose: In preparation for a Phase III comparison of high-dose versus standard-dose radiation therapy, this Phase I/II study was initiated to establish the maximum tolerated dose of radiation therapy in the setting of concurrent chemotherapy, using three-dimensional conformal radiation therapy for non-small-cell lung cancer. Methods and Materials: Eligibility included patients with histologically proven, unresectable Stages I to III non-small-cell lung cancer. Concurrent chemotherapy consisted of paclitaxel, 50 mg/m{sup 2}, and carboplatin, AUC of 2, given weekly. The radiation dose was to be sequentially intensified by increasing the daily fraction size, starting from 75.25 Gy/35 fractions. Results: The Phase I portion of this study accrued 17 patients from 10 institutions and was closed in January 2004. After the initial 8 patients were accrued to cohort 1, the trial closed temporarily on September 26, 2002, due to reported toxicity. Two acute treatment-related dose-limiting toxicities (DLTs) were reported at the time: a case of grade 5 and grade 3 radiation pneumonitis. The protocol, therefore, was revised to de-escalate the radiation therapy dose (74 Gy/37 fractions). Patients in cohort 1 continued to develop toxicity, with 6/8 (75%) patients eventually developing grade >=3 events. Cohort 2 accrued 9 patients. There was one DLT, a grade 3 esophagitis, in cohort 2 in the first 5 patients (1/5 patients) and no DLTs for the next 2 patients (0/2 patients). Conclusions: The maximum tolerated dose was determined to be 74 Gy/37 fractions (2.0 Gy per fraction) using three-dimensional conformal radiation therapy with concurrent paclitaxel and carboplatin therapy. This dose level in the Phase II portion has been well tolerated, with low rates of acute and late lung toxicities.

  7. Radiation dose in coronary angiography and intervention: initial results from the establishment of a multi-centre diagnostic reference level in Queensland public hospitals

    SciTech Connect

    Crowhurst, James A; Whitby, Mark; Thiele, David; Halligan, Toni; Westerink, Adam; Crown, Suzanne; Milne, Jillian

    2014-09-15

    Radiation dose to patients undergoing invasive coronary angiography (ICA) is relatively high. Guidelines suggest that a local benchmark or diagnostic reference level (DRL) be established for these procedures. This study sought to create a DRL for ICA procedures in Queensland public hospitals. Data were collected for all Cardiac Catheter Laboratories in Queensland public hospitals. Data were collected for diagnostic coronary angiography (CA) and single-vessel percutaneous intervention (PCI) procedures. Dose area product (P{sub KA}), skin surface entrance dose (K{sub AR}), fluoroscopy time (FT), and patient height and weight were collected for 3 months. The DRL was set from the 75th percentile of the P{sub KA.} 2590 patients were included in the CA group where the median FT was 3.5 min (inter-quartile range = 2.3–6.1). Median K{sub AR} = 581 mGy (374–876). Median P{sub KA} = 3908 uGym{sup 2} (2489–5865) DRL = 5865 uGym{sup 2}. 947 patients were included in the PCI group where median FT was 11.2 min (7.7–17.4). Median K{sub AR} = 1501 mGy (928–2224). Median P{sub KA} = 8736 uGym{sup 2} (5449–12,900) DRL = 12,900 uGym{sup 2}. This study established a benchmark for radiation dose for diagnostic and interventional coronary angiography in Queensland public facilities.

  8. A CCD-based optical CT scanner for high-resolution 3D imaging of radiation dose distributions: equipment specifications, optical simulations and preliminary results

    NASA Astrophysics Data System (ADS)

    Doran, Simon J.; Klein Koerkamp, Koen; Bero, Mamdouh A.; Jenneson, Paul; Morton, Edward J.; Gilboy, Walter B.

    2001-12-01

    Methods based on magnetic resonance imaging for the measurement of three-dimensional distributions of radiation dose are highly developed. However, relatively little work has been done on optical computed tomography (OCT). This paper describes a new OCT scanner based on a broad beam light source and a two-dimensional charge-coupled device (CCD) detector. A number of key design features are discussed including the light source; the scanning tank, turntable and stepper motor control; the diffuser screen onto which images are projected and the detector. It is shown that the non-uniform pixel sensitivity of the low-cost CCD detector used and the granularity of the diffuser screen lead to a serious ring artefact in the reconstructed images. Methods are described for eliminating this. The problems arising from reflection and refraction at the walls of the gel container are explained. Optical ray-tracing simulations are presented for cylindrical containers with a variety of radii and verified experimentally. Small changes in the model parameters lead to large variations in the signal intensity observed in the projection data. The effect of imperfect containers on data quality is discussed and a method based on a 'correction scan' is shown to be successful in correcting many of the related image artefacts. The results of two tomography experiments are presented. In the first experiment, a radiochromic Fricke gel sample was exposed four times in different positions to a 100 kVp x-ray beam perpendicular to the plane of imaging. Images of absorbed dose with slice thickness of 140 μm were acquired, with 'true' in-plane resolution of 560 × 560 μm2 at the edge of the 72 mm field of view and correspondingly higher resolution at the centre. The nominal doses measured correlated well with the known exposure times. The second experiment demonstrated the well known phenomenon of diffusion in the dosemeter gels and yielded a value of (0.12 +/- 0.02) mm2 s-1 for the diffusion

  9. A CCD-based optical CT scanner for high-resolution 3D imaging of radiation dose distributions: equipment specifications, optical simulations and preliminary results.

    PubMed

    Doran, S J; Koerkamp, K K; Bero, M A; Jenneson, P; Morton, E J; Gilboy, W B

    2001-12-01

    Methods based on magnetic resonance imaging for the measurement of three-dimensional distributions of radiation dose are highly developed. However, relatively little work has been done on optical computed tomography (OCT). This paper describes a new OCT scanner based on a broad beam light source and a two-dimensional charge-coupled device (CCD) detector. A number of key design features are discussed including the light source; the scanning tank, turntable and stepper motor control; the diffuser screen onto which images are projected and the detector. It is shown that the non-uniform pixel sensitivity of the low-cost CCD detector used and the granularity of the diffuser screen lead to a serious ring artefact in the reconstructed images. Methods are described for eliminating this. The problems arising from reflection and refraction at the walls of the gel container are explained. Optical ray-tracing simulations are presented for cylindrical containers with a variety of radii and verified experimentally. Small changes in the model parameters lead to large variations in the signal intensity observed in the projection data. The effect of imperfect containers on data quality is discussed and a method based on a 'correction scan' is shown to be successful in correcting many of the related image artefacts. The results of two tomography experiments are presented. In the first experiment, a radiochromic Fricke gel sample was exposed four times in different positions to a 100 kVp x-ray beam perpendicular to the plane of imaging. Images of absorbed dose with slice thickness of 140 microm were acquired. with 'true' in-plane resolution of 560 x 560 microm2 at the edge of the 72 mm field of view and correspondingly higher resolution at the centre. The nominal doses measured correlated well with the known exposure times. The second experiment demonstrated the well known phenomenon of diffusion in the dosemeter gels and yielded a value of (0.12 +/- 0.02) mm2 s(-1) for the diffusion

  10. Radiation dose rates from UF{sub 6} cylinders

    SciTech Connect

    Friend, P.J.

    1991-12-31

    This paper describes the results of many studies, both theoretical and experimental, which have been carried out by Urenco over the last 15 years into radiation dose rates from uranium hexafluoride (UF{sub 6}) cylinders. The contents of the cylinder, its history, and the geometry all affect the radiation dose rate. These factors are all examined in detail. Actual and predicted dose rates are compared with levels permitted by IAEA transport regulations.

  11. 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)

    SciTech Connect

    Huddart, Robert A.; Hall, Emma; Hussain, Syed A.; Jenkins, Peter; Rawlings, Christine; Tremlett, Jean; Crundwell, Malcolm; Adab, Fawzi A.; Sheehan, Denise; Syndikus, Isabel; Hendron, Carey; Lewis, Rebecca; Waters, Rachel; James, Nicholas D.

    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. The 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.

  12. Radiation dose estimates for copper-64 citrate in man

    SciTech Connect

    Crook, J.E.; Carlton, J.E.; Stabin, M.; Watson, E.

    1985-01-01

    Tumor imaging agents suitable for use with positron emission tomographs are constantly sought. We have performed studies with animal-tumor-bearing models that have demonstrated the rapid uptake of copper-64. The radiation dose estimates for man indicate that the intravenous administration of 7.0 mCi would result in radiation doses to the kidney of 9.8 to 10.5 rads with other organs receiving substantially less radiation. 5 refs., 3 tabs.

  13. Radiation dose distributions due to sudden ejection of cobalt device.

    PubMed

    Abdelhady, Amr

    2016-09-01

    The evaluation of the radiation dose during accident in a nuclear reactor is of great concern from the viewpoint of safety. One of important accident must be analyzed and may be occurred in open pool type reactor is the rejection of cobalt device. The study is evaluating the dose rate levels resulting from upset withdrawal of co device especially the radiation dose received by the operator in the control room. Study of indirect radiation exposure to the environment due to skyshine effect is also taken into consideration in order to evaluate the radiation dose levels around the reactor during the ejection trip. Microshield, SHLDUTIL, and MCSky codes were used in this study to calculate the radiation dose profiles during cobalt device ejection trip inside and outside the reactor building. PMID:27423021

  14. Dose assurance in radiation processing plants

    NASA Astrophysics Data System (ADS)

    Miller, A.; Chadwick, K. H.; Nam, J. W.

    Radiation processing relies to a large extent on dosimetry as control of proper operation. This applies in particular to radiation sterilization of medical products and food treatment, but also during development of any other process. The assurance that proper dosimetry is performed at the radiation processing plant can be obtained through the mediation of an international organization, and the IAEA is now implementing a dose assurance service for industrial radiation processing.

  15. Radiation dose to the global flying population.

    PubMed

    Alvarez, Luis E; Eastham, Sebastian D; Barrett, Steven R H

    2016-03-01

    Civil airliner passengers and crew are exposed to elevated levels of radiation relative to being at sea level. Previous studies have assessed the radiation dose received in particular cases or for cohort studies. Here we present the first estimate of the total radiation dose received by the worldwide civilian flying population. We simulated flights globally from 2000 to 2013 using schedule data, applying a radiation propagation code to estimate the dose associated with each flight. Passengers flying in Europe and North America exceed the International Commission on Radiological Protection annual dose limits at an annual average of 510 or 420 flight hours per year, respectively. However, this falls to 160 or 120 h on specific routes under maximum exposure conditions. PMID:26769857

  16. Patient Radiation Doses from Diagnostic Radiology.

    ERIC Educational Resources Information Center

    Hart, D.

    1996-01-01

    Explains how x-ray doses to patients are measured. Describes how different techniques expose patients to differing amounts of ionizing radiation. Compares these figures with other natural and man-made sources. (Author/MKR)

  17. Gamma Radiation Doses In Sweden

    NASA Astrophysics Data System (ADS)

    Almgren, Sara; Barregârd, Lars; Isaksson, Mats

    2008-08-01

    Gamma dose rate measurements were performed in one urban and one rural area using thermoluminescence dosimeters (TLD) worn by 46 participants and placed in their dwellings. The personal effective dose rates were 0.096±0.019(1 SD) and 0.092±0.016(1 SD)μSv/h in the urban and rural area, respectively. The corresponding dose rates in the dwellings were 0.11±0.042(1 SD) and 0.091±0.026(1 SD)μSv/h. However, the differences between the areas were not significant. The values were higher in buildings made of concrete than of wood and higher in apartments than in detached houses. Also, 222Rn measurements were performed in each dwelling, which showed no correlation with the gamma dose rates in the dwellings.

  18. Gamma Radiation Doses In Sweden

    SciTech Connect

    Almgren, Sara; Isaksson, Mats; Barregaard, Lars

    2008-08-07

    Gamma dose rate measurements were performed in one urban and one rural area using thermoluminescence dosimeters (TLD) worn by 46 participants and placed in their dwellings. The personal effective dose rates were 0.096{+-}0.019(1 SD) and 0.092{+-}0.016(1 SD){mu}Sv/h in the urban and rural area, respectively. The corresponding dose rates in the dwellings were 0.11{+-}0.042(1 SD) and 0.091{+-}0.026(1 SD){mu}Sv/h. However, the differences between the areas were not significant. The values were higher in buildings made of concrete than of wood and higher in apartments than in detached houses. Also, {sup 222}Rn measurements were performed in each dwelling, which showed no correlation with the gamma dose rates in the dwellings.

  19. Occupational radiation doses to operators performing cardiac catheterization procedures.

    PubMed

    Kim, Kwang Pyo; Miller, Donald L; Balter, Stephen; Kleinerman, Ruth A; Linet, Martha S; Kwon, Deukwoo; Simon, Steven L

    2008-03-01

    improvement. Doses were not reduced over time for PCI. The increased complexity of medical procedures appears to have offset dose reductions due to improvements in technology. The large variation in operator doses observed for the same type of procedure suggests that optimizing procedure protocols and implementing general use of the most effective types of protective devices and shields may reduce occupational radiation doses to operators. We had considerable difficulty in comparing reported dosimetry results because of significant differences in dosimetric methods used in each study and multiple factors influencing the actual doses received. Better standardization of dosimetric methods will facilitate future analyses aimed at determining how well medical radiation workers are being protected. PMID:18301095

  20. Doses from Medical Radiation Sources

    MedlinePlus

    ... radiation dosimetry. Continuing Medical Education Article, Journal of Nuclear Medicine 41(5):863–873; 2000. © 2016 Health Physics Society Site Map | Privacy Statement | Disclaimer | Webmaster

  1. Radiation Dose from Reentrant Electrons

    NASA Technical Reports Server (NTRS)

    Badhwar, G.D.; Cleghorn, T. E.; Watts, J.

    2003-01-01

    In estimating the crew exposures during an EVA, the contribution of reentrant electrons has always been neglected. Although the flux of these electrons is small compared to the flux of trapped electrons, their energy spectrum extends to several GeV compared to about 7 MeV for trapped electrons. This is also true of splash electrons. Using the measured reentrant electron energy spectra, it is shown that the dose contribution of these electrons to the blood forming organs (BFO) is more than 10 times greater than that from the trapped electrons. The calculations also show that the dose-depth response is a very slowly changing function of depth, and thus adding reasonable amounts of additional shielding would not significantly lower the dose to BFO.

  2. Low-dose radiation: a cause of breast cancer

    SciTech Connect

    Land, C.E.

    1980-08-15

    It is likely that the breast is the organ most sensitive to radiation carcinogenesis in postpubertal women. Studies of different exposed populations have yielded remarkably consistent results, in spite of wide differences in underlying breast cancer rates and conditions of exposure. Excess risk is approximately proportional to dose, and is relatively independent of ionization density and fractionization of dose. This implies that the risk associated with low-dose exposures to ionizing radiation can be estimated with some confidence from higher-dose data. Excess risk is heavily dependent on age at exposure but relatively independent of population differences in normal risk. The temporal patterns after exposure of both radiation-induced and naturally occurring breast cancer are similar, suggesting a strong influence of factors other than radiation on radiation-induced breast cancer. Uncertainties remain about risks from exposures before puberty and after menopause.

  3. Results of radiation treatment of cerebellar medulloblastoma

    SciTech Connect

    Chin, H.W.; Maruyama, Y.

    1981-06-01

    A review of 20 patients with medulloblastoma who were treated with radiation treatment at the University of Kentucky Medical Center is presented. The age range was 1.5 to 31 years; only five patients were older than 16 years of age. A relationship between radiation dose and survival was obtained. A 5-year disease-free survival of 80% was obtained with a radiation dose of 5000 rad and more whereas only 15% of patients survived five years with a radiation dose of less than 5000. Treatment failures were mainly a result of local recurrence. This occurred in 78% of patients who were treated with radiation dosage of less than 5000 rad. The development of hydrocephalus appeared to be because of advanced disease and no 5-year survivors were noted in five patients who underwent systemic shunting procedure. A review of published data also supports a dose-dependent 5-year survival. Effective radiation treatment methods, along with doses to 5000 to 5500 rad, appear to lead to long term survival, frequent tumor cure and high performance outcome.

  4. Commentary 2 to Cox and Little: radiation-induced oncogenic transformation: the interplay between dose, dose protraction, and radiation quality

    NASA Technical Reports Server (NTRS)

    Brenner, D. J.; Hall, E. J.

    1992-01-01

    There is now a substantial body of evidence for end points such as oncogenic transformation in vitro, and carcinogenesis and life shortening in vivo, suggesting that dose protraction leads to an increase in effectiveness relative to a single, acute exposure--at least for radiations of medium linear energy transfer (LET) such as neutrons. Table I contains a summary of the pertinent data from studies in which the effect is seen. [table: see text] This phenomenon has come to be known as the "inverse dose rate effect," because it is in marked contrast to the situation at low LET, where protraction in delivery of a dose of radiation, either by fractionation or low dose rate, results in a decreased biological effect; additionally, at medium and high LET, for radiobiological end points such as clonogenic survival, the biological effectiveness is independent of protraction. The quantity and quality of the published reports on the "inverse dose rate effect" leaves little doubt that the effect is real, but the available evidence indicates that the magnitude of the effect is due to a complex interplay between dose, dose rate, and radiation quality. Here, we first summarize the available data on the inverse dose rate effect and suggest that it follows a consistent pattern in regard to dose, dose rate, and radiation quality; second, we describe a model that predicts these features; and, finally, we describe the significance of the effect for radiation protection.

  5. [Low-dose radiation effects and intracellular signaling pathways].

    PubMed

    Suzuki, Keiji; Kodama, Seiji; Watanabe, Masami

    2006-10-01

    Accumulated evidence has shown that exposure to low-dose radiation, especially doses less than 0.1 Gy, induces observable effects on mammalian cells. However, the underlying molecular mechanisms have not yet been clarified. Recently, it has been shown that low-dose radiation stimulates growth factor receptor, which results in a sequential activation of the mitogen-activated protein kinase pathway. In addition to the activation of the membrane-bound pathways, it is becoming evident that nuclear pathways are also activated by low-dose radiation. Ionizing radiation has detrimental effects on chromatin structure, since radiation-induced DNA double-strand breaks result in discontinuity of nucleosomes. Recently, it has been shown that ATM protein, the product of the ATM gene mutated in ataxia-telangiectasia, recognizes alteration in the chromatin structure, and it is activated through intermolecular autophosphorylation at serine 1981. Using antibodies against phosphorylated ATM, we found that the activated and phosphorylated ATM protein is detected as discrete foci in the nucleus between doses of 10 mGy and 1 Gy. Interestingly, the size of the foci induced by low-dose radiation was equivalent to the foci induced by high-dose radiation. These results indicate that the initial signal is amplified through foci growth, and cells evolve a system by which they can respond to a small number of DNA double-strand breaks. From these results, it can be concluded that low-dose radiation is sensed both in the membrane and in the nucleus, and activation of multiple signal transduction pathways could be involved in manifestations of low-dose effects. PMID:17016017

  6. Radiation dose from cigarette tobacco

    SciTech Connect

    Papastefanou, C.

    2008-08-07

    The radioactivity in tobacco leaves collected from 15 different regions of Greece before cigarette production was studied in order to estimate the effective dose from cigarette tobacco due to the naturally occurring primordial radionuclides, such as {sup 226}Ra and {sup 210}Pb of the uranium series and {sup 228}Ra of the thorium series and/or man-made produced radionuclides, such as {sup 137}Cs of Chernobyl origin. Gamma-ray spectrometry was applied using Ge planar and coaxial type detectors of high resolution and high efficiency. It was concluded that the annual effective dose due to inhalation for adults (smokers) for {sup 226}Ra varied from 42.5 to 178.6 {mu}Sv y{sup -1} (average 79.7 {mu}Sv y{sup -1}), while for {sup 228}Ra from 19.3 to 116.0 {mu}Sv y{sup -1} (average 67.1 {mu}Sv y{sup -1}) and for {sup 210}Pb from 47.0 to 134.9 {mu}Sv y{sup -1} (average 104.7 {mu}Sv y{sup -1}), that is the same order of magnitude for each radionuclide. The sum of the effective dose of the three natural radionuclides varied from 151.9 to 401.3 {mu}Sv y{sup -1} (average 251.5 {mu}Sv y{sup -1}). The annual effective dose from {sup 137}Cs of Chernobyl origin was three orders of magnitude lower as it varied from 70.4 to 410.4 nSv y{sup -1} (average 199.3 nSv y{sup -1})

  7. Radiation Dose from Cigarette Tobacco

    NASA Astrophysics Data System (ADS)

    Papastefanou, C.

    2008-08-01

    The radioactivity in tobacco leaves collected from 15 different regions of Greece before cigarette production was studied in order to estimate the effective dose from cigarette tobacco due to the naturally occurring primordial radionuclides, such as 226Ra and 210Pb of the uranium series and 228Ra of the thorium series and/or man-made produced radionuclides, such as 137Cs of Chernobyl origin. Gamma-ray spectrometry was applied using Ge planar and coaxial type detectors of high resolution and high efficiency. It was concluded that the annual effective dose due to inhalation for adults (smokers) for 226Ra varied from 42.5 to 178.6 μSv y-1 (average 79.7 μSv y-1), while for 228Ra from 19.3 to 116.0 μSv y-1 (average 67.1 μSv y-1) and for 210Pb from 47.0 to 134.9 μSv y-1 (average 104.7 μSv y-1), that is the same order of magnitude for each radionuclide. The sum of the effective dose of the three natural radionuclides varied from 151.9 to 401.3 μSv y-1 (average 251.5 μSv y-1). The annual effective dose from 137Cs of Chernobyl origin was three orders of magnitude lower as it varied from 70.4 to 410.4 nSv y-1 (average 199.3 nSv y-1).

  8. Determining radiation dose to residents of radiation-contaminated buildings

    SciTech Connect

    Lee, J.J.S.; Wu, T.H.; Chong, N.S.; Dong, S.L.

    1999-08-01

    There are more than one thousand residents who lived in about 140 radiation-contaminated buildings and received the assessed radiation dose equivalent over 5 mSv/year. In this paper, a systematic approach to dose reconstruction is proposed for evaluating radiation dose equivalent to the residents. The approach includes area survey and exposure measurement, source identification and energy spectrum analysis, special designed TLD-embedded badges for residents to wear and organ dose estimation with Rando phantom simulation. From the study, it is concluded that the ionization chamber should still be considered as the primary modality for external dose measurement. However, lacking of accurate daily activity patterns of the residents, the dose equivalent estimation with the chamber measurements would be somehow overestimated. The encountered limitation could be compensated with the use of the TLD badges and Rando phantom simulation that could also provide more information for internal organ dose equivalent estimations. As the radiation patterns in the buildings are highly anisotropic, which strongly depends on the differences of structural and indoor layouts, it demands a mathematical model dealing with the above concerns. Also, further collaborations with studies on biological markers of the residents would make the entire dose equivalent estimation more helpful and reliable.

  9. Wide-range radiation dose monitor

    DOEpatents

    Kopp, Manfred K.

    1986-01-01

    A radiation dose-rate monitor is provided which operates in a conventional linear mode for radiation in the 0 to 0.5 R/h range and utilizes a nonlinear mode of operation for sensing radiation from 0.5 R/h to over 500 R/h. The nonlinear mode is achieved by a feedback circuit which adjusts the high voltage bias of the proportional counter, and hence its gas gain, in accordance with the amount of radiation being monitored. This allows compression of readout onto a single scale over the range of 0 to greater than 500 R/h without scale switching operations.

  10. Wide-range radiation dose monitor

    DOEpatents

    Kopp, M.K.

    1984-09-20

    A radiation dose-rate monitor is provided which operates in a conventional linear mode for radiation in the 0 to 0.5 R/h range and utilizes a nonlinear mode of operation for sensing radiation from 0.5 R/h to over 500 R/h. The nonlinear mode is achieved by a feedback circuit which adjusts the high voltage bias of the proportional counter, and hence its gas gain, in accordance with the amount of radiation being monitored. This allows compression of readout onto a single scale over the range of 0 to greater than 500 R/h without scale switching operations.

  11. Patient perspectives on radiation dose.

    PubMed

    Graff, Joyce

    2014-03-01

    People with genetic cancer syndromes have a special interest in imaging. They also have special risk factors with respect to radiation. They need to utilize the potential of imaging while keeping in mind concerns about cumulative radiation exposure. Before imaging, early detection of problems was limited. With imaging, issues can be identified when they are small and a good plan of action can be developed early. Operations can be planned and metastatic cancer avoided. The positive contribution of imaging to the care of these patients can be profound. However, this additional surveillance is not without cost. An average patient with 1 of these syndromes will undergo 100 or more scans in their lifetime. Imaging professionals should be able to describe the risks and benefits of each scan in terms that the patient and the ordering physician can understand to make smart decisions about the ordering of scans. Why CT versus MRI? When are x-ray or ultrasound appropriate, and when are they not? What are the costs and the medical risks for the patient? What value does this picture add for the physician? Is there a way to answer the medical question with a test other than a scan? Medicine is a team sport, and the patient is an integral member of the team. PMID:24589397

  12. KERMA-based radiation dose management system for real-time patient dose measurement

    NASA Astrophysics Data System (ADS)

    Kim, Kyo-Tae; Heo, Ye-Ji; Oh, Kyung-Min; Nam, Sang-Hee; Kang, Sang-Sik; Park, Ji-Koon; Song, Yong-Keun; Park, Sung-Kwang

    2016-07-01

    Because systems that reduce radiation exposure during diagnostic procedures must be developed, significant time and financial resources have been invested in constructing radiation dose management systems. In the present study, the characteristics of an existing ionization-based system were compared to those of a system based on the kinetic energy released per unit mass (KERMA). Furthermore, the feasibility of using the KERMA-based system for patient radiation dose management was verified. The ionization-based system corrected the effects resulting from radiation parameter perturbations in general radiography whereas the KERMA-based system did not. Because of this difference, the KERMA-based radiation dose management system might overestimate the patient's radiation dose due to changes in the radiation conditions. Therefore, if a correction factor describing the correlation between the systems is applied to resolve this issue, then a radiation dose management system can be developed that will enable real-time measurement of the patient's radiation exposure and acquisition of diagnostic images.

  13. SU-E-J-08: Comparison of Unintended Radiation Doses to Organs at Risk Resulting From the Out-Of-Field Therapeutic Beams and From Image-Guidance X-Ray Procedures

    SciTech Connect

    Ding, G; Wang, L

    2015-06-15

    Purpose: The unintended radiation dose to organs at risk (OAR) can be contributed from imaging guidance procedures as well as from leakage and scatter of therapeutic beams. This study compares the imaging dose with the unintended out-of-field therapeutic dose to patient sensitive organs. Methods: The Monte Carlo EGSnrc user codes, BEAMnrc and DOSXYZnrc, were used to simulate kV X-ray sources from imaging devices as well as the therapeutic IMRT/VMAT beams and to calculate doses to target and OARs on patient treatment planning CT images. The accuracy of the Monte Carlo simulations was benchmarked against measurements in phantoms. The dose-volume histogram was utilized in analyzing the patient organ doses. Results: The dose resulting from Standard Head kV-CBCT scans to bone and soft tissues ranges from 0.7 to 1.1 cGy and from 0.03 to 0.3 cGy, respectively. The dose resulting from Thorax scans on the chest to bone and soft tissues ranges from 1.1 to 1.8 cGy and from 0.3 to 0.6 cGy, respectively. The dose resulting from Pelvis scans on the abdomen to bone and soft tissues range from 3.2 to 4.2 cGy and from 1.2 to 2.2 cGy, respectively. The out-of-field doses to OAR are sensitive to the distance between the treated target and the OAR. For a typical Head-and-Neck IMRT/VMAT treatment the out-of-field doses to eyes are 1–3% of the target dose, or 2–6 cGy per fraction. Conclusion: The imaging doses to OAR are predictable based on the imaging protocols used when OARs are within the imaged volume and can be estimated and accounted for by using tabulated values. The unintended out-of-field doses are proportional to the target dose, strongly depend on the distance between the treated target and OAR, and are generally higher comparing to the imaging dose. This work was partially supported by Varian research grant VUMC40590.

  14. A Biodosimeter for Multiparametric Determination of Radiation Dose, Radiation Quality, and Radiation Risk

    NASA Technical Reports Server (NTRS)

    Richmond, Robert; Cruz, Angela; Jansen, Heather; Bors, Karen

    2003-01-01

    the quality of the radiation dose absorbed by individual cells. The principal value of this reported potential multiparametric cellular biodosimeter is suggested to be that it justifies a search for similar but more robust radiogenic assays. That is, K18 is only one radiation dose-sensitive expressed protein, whereas analytical techniques of genomics and proteomics can be used to simultaneously analyze multiple gene and protein expressions resulting from radiation-dose absorption. The potential usefulness of multiparametric cellular biodosimeters will be best realized from quantitatively profiling these multiple markers using these modern techniques.

  15. Radiation dose in temporomandibular joint zonography

    SciTech Connect

    Coucke, M.E.; Bourgoignie, R.R.; Dermaut, L.R.; Bourgoignie, K.A.; Jacobs, R.J. )

    1991-06-01

    Temporomandibular joint morphology and function can be evaluated by panoramic zonography. Thermoluminescent dosimetry was applied to evaluate the radiation dose to predetermined sites on a phantom eye, thyroid, pituitary, and parotid, and the dose distribution on the skin of the head and neck when the TMJ program of the Zonarc panoramic x-ray unit was used. Findings are discussed with reference to similar radiographic techniques.

  16. Imaging of Radiation Dose for Stereotactic Radiosurgery.

    PubMed

    Guan, Timothy Y; Almond, Peter R; Park, Hwan C; Lindberg, Robert D; Shields, Christopher B

    2015-01-01

    The distributions of radiation dose for stereotactic radiosurgery, using a modified linear accelerator (Philips SL-25 and SRS-200), have been studied by using three different dosimeters: (1) ferrous-agarose-xylenol orange (FAX) gels, (2) TLD, and (3) thick-emulsion GafChromic dye film. These dosimeters were loaded into a small volume of defect in a phantom head. A regular linac stereotactic radiosurgery treatment was then given to the phantom head for each type of dosimeter. The measured radiation dose and its distributions were found to be in good agreement with those calculated by the treatment planning computer. PMID:27421869

  17. Status of eye lens radiation dose monitoring in European hospitals.

    PubMed

    Carinou, Eleftheria; Ginjaume, Merce; O'Connor, Una; Kopec, Renata; Sans Merce, Marta

    2014-12-01

    A questionnaire was developed by the members of WG12 of EURADOS in order to establish an overview of the current status of eye lens radiation dose monitoring in hospitals. The questionnaire was sent to medical physicists and radiation protection officers in hospitals across Europe. Specific topics were addressed in the questionnaire such as: knowledge of the proposed eye lens dose limit; monitoring and dosimetry issues; training and radiation protection measures. The results of the survey highlighted that the new eye lens dose limit can be exceeded in interventional radiology procedures and that eye lens protection is crucial. Personnel should be properly trained in how to use protective equipment in order to keep eye lens doses as low as reasonably achievable. Finally, the results also highlighted the need to improve the design of eye dosemeters in order to ensure satisfactory use by workers. PMID:25222935

  18. Automated extraction of radiation dose information for CT examinations.

    PubMed

    Cook, Tessa S; Zimmerman, Stefan; Maidment, Andrew D A; Kim, Woojin; Boonn, William W

    2010-11-01

    Exposure to radiation as a result of medical imaging is currently in the spotlight, receiving attention from Congress as well as the lay press. Although scanner manufacturers are moving toward including effective dose information in the Digital Imaging and Communications in Medicine headers of imaging studies, there is a vast repository of retrospective CT data at every imaging center that stores dose information in an image-based dose sheet. As such, it is difficult for imaging centers to participate in the ACR's Dose Index Registry. The authors have designed an automated extraction system to query their PACS archive and parse CT examinations to extract the dose information stored in each dose sheet. First, an open-source optical character recognition program processes each dose sheet and converts the information to American Standard Code for Information Interchange (ASCII) text. Each text file is parsed, and radiation dose information is extracted and stored in a database which can be queried using an existing pathology and radiology enterprise search tool. Using this automated extraction pipeline, it is possible to perform dose analysis on the >800,000 CT examinations in the PACS archive and generate dose reports for all of these patients. It is also possible to more effectively educate technologists, radiologists, and referring physicians about exposure to radiation from CT by generating report cards for interpreted and performed studies. The automated extraction pipeline enables compliance with the ACR's reporting guidelines and greater awareness of radiation dose to patients, thus resulting in improved patient care and management. PMID:21040869

  19. Peripheral Doses from Noncoplanar IMRT for Pediatric Radiation Therapy

    SciTech Connect

    Kan, Monica W.K.; Leung, Lucullus H.T.; Kwong, Dora L.W.; Wong, Wicger; Lam, Nelson

    2010-01-01

    The use of noncoplanar intensity-modulated radiation therapy (IMRT) might result in better sparing of some critical organs because of a higher degree of freedom in beam angle optimization. However, this can lead to a potential increase in peripheral dose compared with coplanar IMRT. The peripheral dose from noncoplanar IMRT has not been previously quantified. This study examines the peripheral dose from noncoplanar IMRT compared with coplanar IMRT for pediatric radiation therapy. Five cases with different pediatric malignancies in head and neck were planned with both coplanar and noncoplanar IMRT techniques. The plans were performed such that the tumor coverage, conformality, and dose uniformity were comparable for both techniques. To measure the peripheral doses of the 2 techniques, thermoluminescent dosimeters (TLD) were placed in 10 different organs of a 5-year-old pediatric anthropomorphic phantom. With the use of noncoplanar beams, the peripheral doses to the spinal cord, bone marrow, lung, and breast were found to be 1.8-2.5 times of those using the coplanar technique. This is mainly because of the additional internal scatter dose from the noncoplanar beams. Although the use of noncoplanar technique can result in better sparing of certain organs such as the optic nerves, lens, or inner ears depending on how the beam angles were optimized on each patient, oncologists should be alert of the possibility of significantly increasing the peripheral doses to certain radiation-sensitive organs such as bone marrow and breast. This might increase the secondary cancer risk to patients at young age.

  20. Space radiation absorbed dose distribution in a human phantom

    NASA Technical Reports Server (NTRS)

    Badhwar, G. D.; Atwell, W.; Badavi, F. F.; Yang, T. C.; Cleghorn, T. F.

    2002-01-01

    The radiation risk to astronauts has always been based on measurements using passive thermoluminescent dosimeters (TLDs). The skin dose is converted to dose equivalent using an average radiation quality factor based on model calculations. The radiological risk estimates, however, are based on organ and tissue doses. This paper describes results from the first space flight (STS-91, 51.65 degrees inclination and approximately 380 km altitude) of a fully instrumented Alderson Rando phantom torso (with head) to relate the skin dose to organ doses. Spatial distributions of absorbed dose in 34 1-inch-thick sections measured using TLDs are described. There is about a 30% change in dose as one moves from the front to the back of the phantom body. Small active dosimeters were developed specifically to provide time-resolved measurements of absorbed dose rates and quality factors at five organ locations (brain, thyroid, heart/lung, stomach and colon) inside the phantom. Using these dosimeters, it was possible to separate the trapped-proton and the galactic cosmic radiation components of the doses. A tissue-equivalent proportional counter (TEPC) and a charged-particle directional spectrometer (CPDS) were flown next to the phantom torso to provide data on the incident internal radiation environment. Accurate models of the shielding distributions at the site of the TEPC, the CPDS and a scalable Computerized Anatomical Male (CAM) model of the phantom torso were developed. These measurements provided a comprehensive data set to map the dose distribution inside a human phantom, and to assess the accuracy and validity of radiation transport models throughout the human body. The results show that for the conditions in the International Space Station (ISS) orbit during periods near the solar minimum, the ratio of the blood-forming organ dose rate to the skin absorbed dose rate is about 80%, and the ratio of the dose equivalents is almost one. The results show that the GCR model dose

  1. Space radiation absorbed dose distribution in a human phantom.

    PubMed

    Badhwar, G D; Atwell, W; Badavi, F F; Yang, T C; Cleghorn, T F

    2002-01-01

    The radiation risk to astronauts has always been based on measurements using passive thermoluminescent dosimeters (TLDs). The skin dose is converted to dose equivalent using an average radiation quality factor based on model calculations. The radiological risk estimates, however, are based on organ and tissue doses. This paper describes results from the first space flight (STS-91, 51.65 degrees inclination and approximately 380 km altitude) of a fully instrumented Alderson Rando phantom torso (with head) to relate the skin dose to organ doses. Spatial distributions of absorbed dose in 34 1-inch-thick sections measured using TLDs are described. There is about a 30% change in dose as one moves from the front to the back of the phantom body. Small active dosimeters were developed specifically to provide time-resolved measurements of absorbed dose rates and quality factors at five organ locations (brain, thyroid, heart/lung, stomach and colon) inside the phantom. Using these dosimeters, it was possible to separate the trapped-proton and the galactic cosmic radiation components of the doses. A tissue-equivalent proportional counter (TEPC) and a charged-particle directional spectrometer (CPDS) were flown next to the phantom torso to provide data on the incident internal radiation environment. Accurate models of the shielding distributions at the site of the TEPC, the CPDS and a scalable Computerized Anatomical Male (CAM) model of the phantom torso were developed. These measurements provided a comprehensive data set to map the dose distribution inside a human phantom, and to assess the accuracy and validity of radiation transport models throughout the human body. The results show that for the conditions in the International Space Station (ISS) orbit during periods near the solar minimum, the ratio of the blood-forming organ dose rate to the skin absorbed dose rate is about 80%, and the ratio of the dose equivalents is almost one. The results show that the GCR model dose

  2. 10 CFR 20.1004 - Units of radiation dose.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Units of radiation dose. 20.1004 Section 20.1004 Energy NUCLEAR REGULATORY COMMISSION STANDARDS FOR PROTECTION AGAINST RADIATION General Provisions § 20.1004 Units of radiation dose. (a) Definitions. As used in this part, the units of radiation dose are:...

  3. Scientific issues in radiation dose reconstruction.

    PubMed

    Toohey, Richard E

    2008-07-01

    Stakeholders have raised numerous issues regarding the scientific basis of radiation dose reconstruction for compensation. These issues can be grouped into three broad categories: data issues, dosimetry issues, and compensation issues. Data issues include demographic data of the worker, changes in site operations over time (both production and exposure control), characterization of episodic vs. chronic exposures, and the use of coworker data. Dosimetry issues include methods for assessment of ambient exposures, missed dose, unmonitored dose, and medical x-ray dose incurred as a condition of employment. Specific issues related to external dose include the sensitivity, angular and energy dependence of personal monitors, exposure geometries, and the accompanying uncertainties. Those related to internal dose include sensitivity of bioassay methods, uncertainties in biokinetic models, appropriate dose coefficients, and modeling uncertainties. Compensation issues include uncertainties in the risk models and use of the 99th percentile of the distribution of probability of causation for awarding compensation. A review of the scientific literature and analysis of each of these issues distinguishes factors that play a major role in the compensation decision from those that do not. PMID:18545027

  4. Agriculture-related radiation dose calculations

    SciTech Connect

    Furr, J.M.; Mayberry, J.J.; Waite, D.A.

    1987-10-01

    Estimates of radiation dose to the public must be made at each stage in the identification and qualification process leading to siting a high-level nuclear waste repository. Specifically considering the ingestion pathway, this paper examines questions of reliability and adequacy of dose calculations in relation to five stages of data availability (geologic province, region, area, location, and mass balance) and three methods of calculation (population, population/food production, and food production driven). Calculations were done using the model PABLM with data for the Permian and Palo Duro Basins and the Deaf Smith County area. Extra effort expended in gathering agricultural data at succeeding environmental characterization levels does not appear justified, since dose estimates do not differ greatly; that effort would be better spent determining usage of food types that contribute most to the total dose; and that consumption rate and the air dispersion factor are critical to assessment of radiation dose via the ingestion pathway. 17 refs., 9 figs., 32 tabs.

  5. Early dose assessment following severe radiation accidents

    SciTech Connect

    Goans, R.E.; Holloway, E.C.; Berger, M.E.; Ricks, R.C.

    1997-04-01

    Early treatment of victims of high level acute whole-body x-ray or gamma exposure has been shown to improve their likelihood of survival. However, in such cases, both the magnitude of the exposure and the dosimetry profile(s) of the victim(s) are often not known in detail for days to weeks. A simple dose-prediction algorithm based on lymphocyte kinetics as documented in prior radiation accidents is presented here. This algorithm provides an estimate of dose within the first 8 h following an acute whole-body exposure. Early lymphocyte depletion kinetics after a severe radiation accident follow a single exponential, L(t) = L{sub o}e{sup -k(D)t}, where k(D) is a rate constant, dependent primarily on the average dose, D. Within the first 8 h post-accident, K(D) may be calculated utilizing serial lymphocyte counts. Data from the REAC/TS Radiation Accident Registry were used to develop a dose-prediction algorithm from 43 gamma exposure cases where both lymphocyte kinetics and dose reconstruction were felt to be reasonably reliable. The inverse relationship D(K) may be molded by a simple two parameter curve of the form D = a/(1 + b/K) in the range 0 {le} D {le} 15 Gy, with fitting parameters (mean {+-} SD): a = 13.6 {+-} 1.7 Gy, and b = 1.0 {+-} 0.20 d{sup -1}. Dose estimated in this manner is intended to serve only as a first approximation to guide initial medical management. 31 refs., 4 figs., 2 tabs.

  6. High-Dose Hypofractionated Proton Beam Radiation Therapy Is Safe and Effective for Central and Peripheral Early-Stage Non-Small Cell Lung Cancer: Results of a 12-Year Experience at Loma Linda University Medical Center

    SciTech Connect

    Bush, David A.; Cheek, Gregory; Zaheer, Salman; Wallen, Jason; Mirshahidi, Hamid; Katerelos, Ari; Grove, Roger; Slater, Jerry D.

    2013-08-01

    Purpose: We update our previous reports on the use of hypofractionated proton beam radiation therapy for early-stage lung cancer patients. Methods and Materials: Eligible subjects had biopsy-proven non-small cell carcinoma of the lung and were medically inoperable or refused surgery. Clinical workup required staging of T1 or T2, N0, M0. Subjects received hypofractionated proton beam therapy to the primary tumor only. The dose delivered was sequentially escalated from 51 to 60 Gy, then to 70 Gy in 10 fractions over 2 weeks. Endpoints included toxicity, pulmonary function, overall survival (OS), disease-specific survival (DSS), and local control (LC). Results: One hundred eleven subjects were analyzed for treatment outcomes. The patient population had the following average characteristics; age 73.2 years, tumor size 3.6 cm, and 1.33 L forced expiratory volume in 1 second. The entire group showed improved OS with increasing dose level (51, 60, and 70 Gy) with a 4-year OS of 18%, 32%, and 51%, respectively (P=.006). Peripheral T1 tumors exhibited LC of 96%, DSS of 88%, and OS of 60% at 4 years. Patients with T2 tumors showed a trend toward improved LC and survival with the 70-Gy dose level. On multivariate analysis, larger tumor size was strongly associated with increased local recurrence and decreased survival. Central versus peripheral location did not correlate with any outcome measures. Clinical radiation pneumonitis was not found to be a significant complication, and no patient required steroid therapy after treatment for radiation pneumonitis. Pulmonary function was well maintained 1 year after treatment. Conclusions: High-dose hypofractionated proton therapy achieves excellent outcomes for lung carcinomas that are peripherally or centrally located. The 70-Gy regimen has been adopted as standard therapy for T1 tumors at our institution. Larger T2 tumors show a trend toward improved outcomes with higher doses, suggesting that better results could be seen with

  7. Impact of Drug Therapy, Radiation Dose, and Dose Rate on Renal Toxicity Following Bone Marrow Transplantation

    SciTech Connect

    Cheng, Jonathan C.; Schultheiss, Timothy E. Wong, Jeffrey Y.C.

    2008-08-01

    Purpose: To demonstrate a radiation dose response and to determine the dosimetric and chemotherapeutic factors that influence the incidence of late renal toxicity following total body irradiation (TBI). Methods and Materials: A comprehensive retrospective review was performed of articles reporting late renal toxicity, along with renal dose, fractionation, dose rate, chemotherapy regimens, and potential nephrotoxic agents. In the final analysis, 12 articles (n = 1,108 patients), consisting of 24 distinct TBI/chemotherapy conditioning regimens were included. Regimens were divided into three subgroups: adults (age {>=}18 years), children (age <18 years), and mixed population (both adults and children). Multivariate logistic regression was performed to identify dosimetric and chemotherapeutic factors significantly associated with late renal complications. Results: Individual analysis was performed on each population subgroup. For the purely adult population, the only significant variable was total dose. For the mixed population, the significant variables included total dose, dose rate, and the use of fludarabine. For the pediatric population, only the use of cyclosporin or teniposide was significant; no dose response was noted. A logistic model was generated with the exclusion of the pediatric population because of its lack of dose response. This model yielded the following significant variables: total dose, dose rate, and number of fractions. Conclusion: A dose response for renal damage after TBI was identified. Fractionation and low dose rates are factors to consider when delivering TBI to patients undergoing bone marrow transplantation. Drug therapy also has a major impact on kidney function and can modify the dose-response function.

  8. Low-Dose Radiation Cataract and Genetic Determinants of Radiosensitivity

    SciTech Connect

    Kleiman, Norman Jay

    2013-11-30

    The lens of the eye is one of the most radiosensitive tissues in the body. Ocular ionizing radiation exposure results in characteristic, dose related, progressive lens changes leading to cataract formation. While initial, early stages of lens opacification may not cause visual disability, the severity of such changes progressively increases with dose until vision is impaired and cataract extraction surgery may be required. Because of the transparency of the eye, radiation induced lens changes can easily be followed non-invasively over time. Thus, the lens provides a unique model system in which to study the effects of low dose ionizing radiation exposure in a complex, highly organized tissue. Despite this observation, considerable uncertainties remain surrounding the relationship between dose and risk of developing radiation cataract. For example, a growing number of human epidemiological findings suggest significant risk among various groups of occupationally and accidentally exposed individuals and confidence intervals that include zero dose. Nevertheless, questions remain concerning the relationship between lens opacities, visual disability, clinical cataract, threshold dose and/or the role of genetics in determining radiosensitivity. Experimentally, the response of the rodent eye to radiation is quite similar to that in humans and thus animal studies are well suited to examine the relationship between radiation exposure, genetic determinants of radiosensitivity and cataractogenesis. The current work has expanded our knowledge of the low-dose effects of X-irradiation or high-LET heavy ion exposure on timing and progression of radiation cataract and has provided new information on the genetic, molecular, biochemical and cell biological features which contribute to this pathology. Furthermore, findings have indicated that single and/or multiple haploinsufficiency for various genes involved in DNA repair and cell cycle checkpoint control, such as Atm, Brca1 or Rad9

  9. Radiation dose and second breast cancer.

    PubMed Central

    Basco, V. E.; Coldman, A. J.; Elwood, J. M.; Young, M. E.

    1985-01-01

    Amongst 14,000 women with breast cancer treated between 1946 and 1982, 194 developed a second primary tumour in the contralateral breast more than one year after diagnosis of the first primary. The radiation dose to the contralateral breast was calculated for each member of this group and also for members of a control group matched for age, year of diagnosis and survival time. Comparison of the groups provides no evidence for radiation induced carcinogenesis on the contralateral breast in these patients. PMID:4041361

  10. Capture and analysis of radiation dose reports for radiology.

    PubMed

    Midgley, S M

    2014-12-01

    Radiographic imaging systems can produce records of exposure and dose parameters for each patient. A variety of file formats are in use including plain text, bit map images showing pictures of written text and radiation dose structured reports as text or extended markup language files. Whilst some of this information is available with image data on the hospital picture archive and communication system, access is restricted to individual patient records, thereby making it difficult to locate multiple records for the same scan protocol. This study considers the exposure records and dose reports from four modalities. Exposure records for mammography and general radiography are utilized for repeat analysis. Dose reports for fluoroscopy and computed tomography (CT) are utilized to study the distribution of patient doses for each protocol. Results for dosimetric quantities measured by General Radiography, Fluoroscopy and CT equipment are summarised and presented in the Appendix. Projection imaging uses the dose (in air) area product and derived quantities including the dose to the reference point as a measure of the air kerma reaching the skin, ignoring movement of the beam for fluoroscopy. CT uses the dose indices CTDIvol and dose length product as a measure of the dose per axial slice, and to the scanned volume. Suitable conversion factors are identified and used to estimate the effective dose to an average size patient (for CT and fluoroscopy) and the entrance skin dose for fluoroscopy. PMID:25315104

  11. Preliminary results of radiation measurements on EURECA

    NASA Technical Reports Server (NTRS)

    Benton, E. V.; Frank, A. L.

    1995-01-01

    The eleven-month duration of the EURECA mission allows long term radiation effects to be studied similarly to those of the Long Duration Exposure Facility (LDEF). Basic data can be generated for projections of crew doses and electronic and computer reliability on spacecraft missions. A radiation experiment has been designed for EURECA which uses passive integrating detectors to measure average radiation levels. The components include a Trackoscope, which employs fourteen plastic nuclear track detector (PNTD) stacks to measure the angular dependence of LET (greater than or equal to 6 keV/microns) radiation. Also included are TLD's for total absorbed doses, thermal/resonance neutron detectors (TRND's) for low energy neutron fluences and a thick PNTD stack for depth dependence measurements. LET spectra are derived from the PNTD measurements. Preliminary TLD results from seven levels within the detector array show that integrated doses inside the flight canister varied from 18.8 plus or minus 0.6 cGy to 38.9 plus or minus 1.2 cGy. The TLD's oriented toward the least shielded direction averaged 53 percent higher in dose than those oriented away from the least shielded direction (minimum shielding toward the least shielded direction varied from 1.13 to 7.9 g/cm(exp 2), Al equivalent). The maximum dose rate on EURECA (1.16 mGy/day) was 37 percent of the maximum measured on LDEF and dose rates at all depths were less than measured on LDEF. The shielding external to the flight canister covered a greater solid angle about the canister than in the LDEF experiments.

  12. The 3D Radiation Dose Analysis For Satellite

    NASA Astrophysics Data System (ADS)

    Cai, Zhenbo; Lin, Guocheng; Chen, Guozhen; Liu, Xia

    2002-01-01

    the earth. These particles come from the Van Allen Belt, Solar Cosmic Ray and Galaxy Cosmic Ray. They have different energy and flux, varying with time and space, and correlating with solar activity tightly. These particles interact with electrical components and materials used on satellites, producing various space radiation effects, which will damage satellite to some extent, or even affect its safety. orbit. Space energy particles inject into components and materials used on satellites, and generate radiation dose by depositing partial or entire energy in them through ionization, which causes their characteristic degradation or even failure. As a consequence, the analysis and protection for radiation dose has been paid more attention during satellite design and manufacture. Designers of satellites need to analyze accurately the space radiation dose while satellites are on orbit, and use the results as the basis for radiation protection designs and ground experiments for satellites. can be calculated, using the model of the trapped proton and the trapped electron in the Van Allen Belt (AE8 and AP8). This is the 1D radiation dose analysis for satellites. Obviously, the mass shielding from the outside space to the computed point in all directions is regarded as a simple sphere shell. The actual structure of satellites, however, is very complex. When energy particles are injecting into a given equipment inside satellite from outside space, they will travel across satellite structure, other equipment, the shell of the given equipment, and so on, which depends greatly on actual layout of satellite. This complex radiation shielding has two characteristics. One is that the shielding masses for the computed point are different in different injecting directions. The other is that for different computed points, the shielding conditions vary in all space directions. Therefore, it is very difficult to tell the differences described above using the 1D radiation analysis, and

  13. Extended range radiation dose-rate monitor

    DOEpatents

    Valentine, Kenneth H.

    1988-01-01

    An extended range dose-rate monitor is provided which utilizes the pulse pileup phenomenon that occurs in conventional counting systems to alter the dynamic response of the system to extend the dose-rate counting range. The current pulses from a solid-state detector generated by radiation events are amplified and shaped prior to applying the pulses to the input of a comparator. The comparator generates one logic pulse for each input pulse which exceeds the comparator reference threshold. These pulses are integrated and applied to a meter calibrated to indicate the measured dose-rate in response to the integrator output. A portion of the output signal from the integrator is fed back to vary the comparator reference threshold in proportion to the output count rate to extend the sensitive dynamic detection range by delaying the asymptotic approach of the integrator output toward full scale as measured by the meter.

  14. Reducing ionizing radiation doses during cardiac interventions in pregnant women

    PubMed Central

    Orchard, Elizabeth; Dix, Sarah; Wilson, Neil; Mackillop, Lucy; Ormerod, Oliver

    2012-01-01

    Background There is concern over ionizing radiation exposure in women who are pregnant or of child-bearing age. Due to the increasing prevalence of congenital and acquired heart disease, the number of women who require cardiac interventions during pregnancy has increased. We have developed protocols for cardiac interventions in pregnant women and women of child-bearing age, aimed at substantially reducing both fluoroscopy duration and radiation doses. Methods Over five years, we performed cardiac interventions on 15 pregnant women, nine postpartum women and four as part of prepregnancy assessment. Fluoroscopy times were minimized by simultaneous use of intracardiac echocardiography, and by using very low frame rates (2/second) during fluoroscopy. Results The procedures most commonly undertaken were closure of atrial septal defect (ASD) or patent foramen ovale (PFO) in 16 women, coronary angiograms in seven, right and left heart catheters in three and two stent placements. The mean screening time for all patients was 2.38 minutes (range 0.48–13.7), the median radiation dose was 66 (8.9–1501) Gy/cm2. The median radiation dose to uterus was 1.92 (0.59–5.47) μGy, and the patient estimated dose was 0.24 (0.095–0.80) mSv. Conclusions Ionizing radiation can be used safely in the management of severe cardiac structural disease in pregnancy, with very low ionizing radiation dose to the mother and extremely low exposure to the fetus. With experience, ionizing radiation doses at our institution have been reduced.

  15. 10 CFR 20.1004 - Units of radiation dose.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 1 2011-01-01 2011-01-01 false Units of radiation dose. 20.1004 Section 20.1004 Energy NUCLEAR REGULATORY COMMISSION STANDARDS FOR PROTECTION AGAINST RADIATION General Provisions § 20.1004 Units of radiation dose. (a) Definitions. As used in this part, the units of radiation dose are: Gray (Gy) is the SI unit of absorbed dose. One...

  16. Relevance of biotic pathways to the long-term regulation of nuclear waste disposal. Estimation of radiation dose to man resulting from biotic transport: the BIOPORT/MAXI1 software package. Volume 5

    SciTech Connect

    McKenzie, D.H.; Cadwell, L.L.; Gano, K.A.; Kennedy, W.E. Jr.; Napier, B.A.; Peloquin, R.A.; Prohammer, L.A.; Simmons, M.A.

    1985-10-01

    BIOPORT/MAXI1 is a collection of five computer codes designed to estimate the potential magnitude of the radiation dose to man resulting from biotic transport processes. Dose to man is calculated for ingestion of agricultural crops grown in contaminated soil, inhalation of resuspended radionuclides, and direct exposure to penetrating radiation resulting from the radionuclide concentrations established in the available soil surface by the biotic transport model. This document is designed as both an instructional and reference document for the BIOPORT/MAXI1 computer software package and has been written for two major audiences. The first audience includes persons concerned with the mathematical models of biological transport of commercial low-level radioactive wastes and the computer algorithms used to implement those models. The second audience includes persons concerned with exercising the computer program and exposure scenarios to obtain results for specific applications. The report contains sections describing the mathematical models, user operation of the computer programs, and program structure. Input and output for five sample problems are included. In addition, listings of the computer programs, data libraries, and dose conversion factors are provided in appendices.

  17. Space Radiation Absorbed Dose Distribution in a Human Phantom Torso

    NASA Technical Reports Server (NTRS)

    Badhwar, G. D.; Yang, T.; Atwell, W.

    2000-01-01

    The flight of a human phantom torso with head that containing active dosimeters at 5 organ sites and 1400 TLDs distributed in 34 1" thick sections is described. Experimental dose rates and quality factors are compared with calculations for shielding distributions at the sites using the Computerized Anatomical Male (CAM) model. The measurements were complemented with those obtained from other instruments. These results have provided the most comprehensive data set to map the dose distribution inside a human and to assess the accuracy of radiation transport models and astronaut radiation risk.

  18. Preliminary results of radiation measurements on EURECA

    NASA Technical Reports Server (NTRS)

    Benton, E. V.; Frank, A. L.

    1995-01-01

    The eleven-month duration of the EURECA mission allows long-term radiation effects to be studied similarly to those of the Long Duration Exposure Facility (LDEF). Basic data can be generated for projections to crew doses and electronic and computer reliability on spacecraft missions. A radiation experiment has been designed for EURECA which uses passive integrating detectors to measure average radiation levels. The components include a Trackoscope, which employs fourteen plastic nuclear track detector (PNTD) stacks to measure the angular dependence of high LET (greater than or equal to 6 keV/micro m) radiation. Also included are TLD's for total absorbed doses, thermal/resonance neutron detectors (TRND's) for low energy neutron fluences and a thick PNTD stack for depth dependence measurements. LET spectra are derived from the PNTD measurements. Preliminary TLD results from seven levels within the detector array show that integrated does inside the flight canister varied from 18.8 +/- 0.6 cGy to 38.9 +/- 1.2 cGy. The TLD's oriented toward the least shielded direction averaged 53% higher in dose than those oriented away from the least shielded direction (minimum shielding toward the least shielded direction varied from 1.13 to 7.9 g/cm(exp 2), Al equivalent). The maximum dose rate on EURECA (1.16 mGy/day) was 37% of the maximum measured on LDEF and dose rates at all depths were less than measured on LDEF. The shielding external to the flight canister covered a greater solid angle about the canister than the LDEF experiments.

  19. Radiation-induced biomarkers for the detection and assessment of absorbed radiation doses

    PubMed Central

    Rana, Sudha; Kumar, Raj; Sultana, Sarwat; Sharma, Rakesh Kumar

    2010-01-01

    Radiation incident involving living organisms is an uncommon but a very serious situation. The first step in medical management including triage is high-throughput assessment of the radiation dose received. Radiation exposure levels can be assessed from viability of cells, cellular organelles such as chromosome and different intermediate metabolites. Oxidative damages by ionizing radiation result in carcinogenesis, lowering of the immune response and, ultimately, damage to the hematopoietic system, gastrointestinal system and central nervous system. Biodosimetry is based on the measurement of the radiation-induced changes, which can correlate them with the absorbed dose. Radiation biomarkers such as chromosome aberration are most widely used. Serum enzymes such as serum amylase and diamine oxidase are the most promising biodosimeters. The level of gene expression and protein are also good biomarkers of radiation. PMID:21829314

  20. Radiation dose to physicians’ eye lens during interventional radiology

    NASA Astrophysics Data System (ADS)

    Bahruddin, N. A.; Hashim, S.; Karim, M. K. A.; Sabarudin, A.; Ang, W. C.; Salehhon, N.; Bakar, K. A.

    2016-03-01

    The demand of interventional radiology has increased, leading to significant risk of radiation where eye lens dose assessment becomes a major concern. In this study, we investigate physicians' eye lens doses during interventional procedures. Measurement were made using TLD-100 (LiF: Mg, Ti) dosimeters and was recorded in equivalent dose at a depth of 0.07 mm, Hp(0.07). Annual Hp(0.07) and annual effective dose were estimated using workload estimation for a year and Von Boetticher algorithm. Our results showed the mean Hp(0.07) dose of 0.33 mSv and 0.20 mSv for left and right eye lens respectively. The highest estimated annual eye lens dose was 29.33 mSv per year, recorded on left eye lens during fistulogram procedure. Five physicians had exceeded 20 mSv dose limit as recommended by international commission of radiological protection (ICRP). It is suggested that frequent training and education on occupational radiation exposure are necessary to increase knowledge and awareness of the physicians’ thus reducing dose during the interventional procedure.

  1. Ultraviolet radiation therapy and UVR dose models

    SciTech Connect

    Grimes, David Robert

    2015-01-15

    Ultraviolet radiation (UVR) has been an effective treatment for a number of chronic skin disorders, and its ability to alleviate these conditions has been well documented. Although nonionizing, exposure to ultraviolet (UV) radiation is still damaging to deoxyribonucleic acid integrity, and has a number of unpleasant side effects ranging from erythema (sunburn) to carcinogenesis. As the conditions treated with this therapy tend to be chronic, exposures are repeated and can be high, increasing the lifetime probability of an adverse event or mutagenic effect. Despite the potential detrimental effects, quantitative ultraviolet dosimetry for phototherapy is an underdeveloped area and better dosimetry would allow clinicians to maximize biological effect whilst minimizing the repercussions of overexposure. This review gives a history and insight into the current state of UVR phototherapy, including an overview of biological effects of UVR, a discussion of UVR production, illness treated by this modality, cabin design and the clinical implementation of phototherapy, as well as clinical dose estimation techniques. Several dose models for ultraviolet phototherapy are also examined, and the need for an accurate computational dose estimation method in ultraviolet phototherapy is discussed.

  2. Radiation Dose and Safety in Cardiac Computed Tomography

    PubMed Central

    Gerber, Thomas C; Kantor, Birgit; McCollough, Cynthia H.

    2009-01-01

    Synopsis As a result of the changes in utilization of imaging procedures that rely on ionizing radiation, the collective dose has increased by over 700% and the annual per-capita dose, by almost 600% over recent years. It is certainly possible that this growing use may have significant effects on public health. Although there are uncertainties related to the accuracy of calculated radiation exposure and the estimated biologic risk, there are measures that can be taken to reduce any potential risks while maintaining diagnostic accuracy. This article will review the existing data regarding biological hazards of radiation exposure associated to medical diagnostic testing, the methodology used to estimate radiation exposure and the measures that can be taken to effectively reduce it. PMID:19766923

  3. Can radiation therapy treatment planning system accurately predict surface doses in postmastectomy radiation therapy patients?

    SciTech Connect

    Wong, Sharon; Back, Michael; Tan, Poh Wee; Lee, Khai Mun; Baggarley, Shaun; Lu, Jaide Jay

    2012-07-01

    Skin doses have been an important factor in the dose prescription for breast radiotherapy. Recent advances in radiotherapy treatment techniques, such as intensity-modulated radiation therapy (IMRT) and new treatment schemes such as hypofractionated breast therapy have made the precise determination of the surface dose necessary. Detailed information of the dose at various depths of the skin is also critical in designing new treatment strategies. The purpose of this work was to assess the accuracy of surface dose calculation by a clinically used treatment planning system and those measured by thermoluminescence dosimeters (TLDs) in a customized chest wall phantom. This study involved the construction of a chest wall phantom for skin dose assessment. Seven TLDs were distributed throughout each right chest wall phantom to give adequate representation of measured radiation doses. Point doses from the CMS Xio Registered-Sign treatment planning system (TPS) were calculated for each relevant TLD positions and results correlated. There were no significant difference between measured absorbed dose by TLD and calculated doses by the TPS (p > 0.05 (1-tailed). Dose accuracy of up to 2.21% was found. The deviations from the calculated absorbed doses were overall larger (3.4%) when wedges and bolus were used. 3D radiotherapy TPS is a useful and accurate tool to assess the accuracy of surface dose. Our studies have shown that radiation treatment accuracy expressed as a comparison between calculated doses (by TPS) and measured doses (by TLD dosimetry) can be accurately predicted for tangential treatment of the chest wall after mastectomy.

  4. Radiation dose study in nuclear medicine using GATE

    NASA Astrophysics Data System (ADS)

    Aguwa, Kasarachi

    Dose as a result of radiation exposure is the notion generally used to disclose the imparted energy in a volume of tissue to a potential biological effect. The basic unit defined by the international system of units (SI system) is the radiation absorbed dose, which is expressed as the mean imparted energy in a mass element of the tissue known as "gray" (Gy) or J/kg. The procedure for ascertaining the absorbed dose is complicated since it involves the radiation transport of numerous types of charged particles and coupled photon interactions. The most precise method is to perform a full 3D Monte Carlo simulation of the radiation transport. There are various Monte Carlo toolkits that have tool compartments for dose calculations and measurements. The dose studies in this thesis were performed using the GEANT4 Application for Emission Tomography (GATE) software (Jan et al., 2011) GATE simulation toolkit has been used extensively in the medical imaging community, due to the fact that it uses the full capabilities of GEANT4. It also utilizes an easy to-learn GATE macro language, which is more accessible than learning the GEANT4/C++ programming language. This work combines GATE with digital phantoms generated using the NCAT (NURBS-based cardiac-torso phantom) toolkit (Segars et al., 2004) to allow efficient and effective estimation of 3D radiation dose maps. The GATE simulation tool has developed into a beneficial tool for Monte Carlo simulations involving both radiotherapy and imaging experiments. This work will present an overview of absorbed dose of common radionuclides used in nuclear medicine and serve as a guide to a user who is setting up a GATE simulation for a PET and SPECT study.

  5. Estimating the Radiation Dose to the Fetus in Prophylactic Internal Iliac Artery Balloon Occlusion: Three Cases

    PubMed Central

    Kai, Kentaro; Hamada, Tomohiro; Yuge, Akitoshi; Kiyosue, Hiro; Nishida, Yoshihiro; Nasu, Kaei; Narahara, Hisashi

    2015-01-01

    Background. Although radiation exposure is of great concern to expecting patients, little information is available on the fetal radiation dose associated with prophylactic internal iliac artery balloon occlusion (IIABO). Here we estimated the fetal radiation dose associated with prophylactic IIABO in Caesarean section (CS). Cases. We report our experience with the IIABO procedure in three consecutive patients with suspected placenta previa/accreta. Fetal radiation dose measurements were conducted prior to each CS by using an anthropomorphic phantom. Based on the simulated value, we calculated the fetal radiation dose as the absorbed dose. We found that the fetal radiation doses ranged from 12.88 to 31.6 mGy. The fetal radiation dose during the prophylactic IIABOs did not exceed 50 mGy. Conclusion. The IIABO procedure could result in a very small increase in the risk of harmful effects to the fetus. PMID:26180648

  6. National Survey of Radiation Doses of Pediatric Chest Radiography in Korea: Analysis of the Factors Affecting Radiation Doses

    PubMed Central

    Kim, Bo Hyun; Goo, Hyun Woo; Yang, Dong Hyun; Oh, Sang Young; Kim, Hyeog Ju; Lee, Kwang Yong; Lee, Jung Eun

    2012-01-01

    Objective To investigate radiation doses in pediatric chest radiography in a national survey and to analyze the factors that affect radiation doses. Materials and Methods The study was based on the results of 149 chest radiography machines in 135 hospitals nationwide. For each machine, a chest radiograph was obtained by using a phantom representing a 5-year-old child (ATOM® dosimetry phantom, model 705-D, CIRS, Norfolk, VA, USA) with each hospital's own protocol. Five glass dosimeters (M-GD352M, Asahi Techno Glass Corporation, Shizuoka, Japan) were horizontally installed at the center of the phantom to measure the dose. Other factors including machine's radiography system, presence of dedicated pediatric radiography machine, presence of an attending pediatric radiologist, and the use of automatic exposure control (AEC) were also evaluated. Results The average protocol for pediatric chest radiography examination in Korea was 94.9 peak kilovoltage and 4.30 milliampere second. The mean entrance surface dose (ESD) during a single examination was 140.4 microgray (µGy). The third quartile, median, minimum and maximum value of ESD were 160.8 µGy, 93.4 µGy, 18.8 µGy, and 2334.6 µGy, respectively. There was no significant dose difference between digital and non-digital radiography systems. The use of AEC significantly reduced radiation doses of pediatric chest radiographs (p < 0.001). Conclusion Our nationwide survey shows that the third quartile, median, and mean ESD for pediatric chest radiograph is 160.8 µGy, 93.4 µGy, and 140.4 µGy, respectively. No significant dose difference is noticed between digital and non-digital radiography systems, and the use of AEC helps significantly reduce radiation doses. PMID:22977329

  7. Measurement of 226Ra, 232Th, 137Cs and 40K activities of Wheat and Corn Products in Ilam Province – Iran and Resultant Annual Ingestion Radiation Dose

    PubMed Central

    CHANGIZI, Vahid; SHAFIEI, Elham; ZAREH, Mohammad Reza

    2013-01-01

    Background: Background: Natural background radiation is the main source of human exposure to radioactive material. Soils naturally have radioactive mineral contents. The aim of this study is to determine natural (238 U, 232 Th, 40 K) and artificial (137 Cs) radioactivity levels in wheat and corn fields of Eilam province. Methods: HPGe detector was used to measure the concentration activity of 238 U and 232 Th series, 40 K and 137 Cs in wheat and corn samples taken from different regions of Eilam province, in Iran. Results: In wheat and corn samples, the average activity concentrations of 226 Ra, 232 Th, 40 K and 137 Cs were found to be 1, 67, 0.5, 91.73, 0.01 and 0.81, 0.85, 101.52, 0.07 Bq/kg (dry weight), respectively. H ex and H in in the present work are lower than 1. The average value of H ex was found to be 0.02 and 0.025 and average value of H in to be found 0.025 and 0.027 in wheat fields samples and corn samples in Eilam provinces, respectively. The obtained values of AGDE are 30.49 mSv/yr for wheat filed samples and 37.89 mSv/yr for corn samples; the AEDE rate values are 5.28 mSv/yr in wheat filed samples and this average value was found to be 6.13 mSv/yr in corn samples in Eilam. Transfer factors (TFs) of long lived radionuclide such as 137 Cs, 226 Ra, 232 Th and 40 K from soils to corn and wheat plants have been studied by radiotracer experiments. Conclusion: The natural radioactivity levels in Eilam province are not at the range of high risk of morbidity and are under international standards. PMID:26056646

  8. Early dose assessment following severe radiation accidents

    SciTech Connect

    Goans, R.E.; Holloway, E.C.

    1996-06-01

    Prompt and aggressive treatment of victims to high level whole-body gamma exposure has been shown to improve their likelihood of survival. However, in such cases, both the magnitude of the accident and the dosimetry profile(s) of the victim(s) are often not known in detail for days to weeks. Medical intervention could therefore be delayed after a major accident because of uncertainties in the initial dose estimate. A simple dose-prediction algorithm based on lymphocyte kinetics as documented in prior radiation accidents is presented here. This algorithm provides an estimate of marrow dose within the first 12-18 h following an acute whole-body gamma exposure. Early lymphocyte depletion curves post-accident follow a single exponential, L(t) = L{sub o}e{sup -k(D)t}, where L{sub o} is the pre- accident lymphocyte count and k(D) is a rate constant, dependent on the average dose, D. Within the first 12-18 h post-accident, K(D) may be calculated utilizing serial lymphocyte counts. Data from the REAC/TS Accident Registry were used to develop a dose prediction algorithm from 43 gamma exposure cases where both lymphocyte kinetics and dose reconstruction were felt to be reasonably reliable. The relationship D(K) is shown to follow a logistic dose response curve of the form D = a/[1 + (K/b){sup c}] in the range 0 {le} D {le} 15 Gy. The fitting parameters (mean {+-} SD) are found to be a = 21.5 {+-} 5.8 Gy, b = 1.75 {+-} 0.99 d{sup -1}, and c = -0.98 {+-} 0.14, respectively. The coefficient of determination r{sup 2} for the fit is 0.90 with an F-value of 174.7. Dose estimated in this manner is intended to serve only as a first approximation to guide initial medical-management. The treatment regimen may then be modified as needed after more exact dosimetry has become available.

  9. Radiation dose-rate meter using an energy-sensitive counter

    DOEpatents

    Kopp, Manfred K.

    1988-01-01

    A radiation dose-rate meter is provided which uses an energy-sensitive detector and combines charge quantization and pulse-rate measurement to monitor radiation dose rates. The charge from each detected photon is quantized by level-sensitive comparators so that the resulting total output pulse rate is proportional to the dose-rate.

  10. Prototype Operational Advances for Atmospheric Radiation Dose Rate Specification

    NASA Astrophysics Data System (ADS)

    Tobiska, W. K.; Bouwer, D.; Bailey, J. J.; Didkovsky, L. V.; Judge, K.; Garrett, H. B.; Atwell, W.; Gersey, B.; Wilkins, R.; Rice, D.; Schunk, R. W.; Bell, D.; Mertens, C. J.; Xu, X.; Crowley, G.; Reynolds, A.; Azeem, I.; Wiltberger, M. J.; Wiley, S.; Bacon, S.; Teets, E.; Sim, A.; Dominik, L.

    2014-12-01

    Space weather's effects upon the near-Earth environment are due to dynamic changes in the energy transfer processes from the Sun's photons, particles, and fields. The coupling between the solar and galactic high-energy particles, the magnetosphere, and atmospheric regions can significantly affect humans and our technology as a result of radiation exposure. Space Environment Technologies (SET) has developed innovative, new space weather observations that will become part of the toolset that is transitioned into operational use. One prototype operational system for providing timely information about the effects of space weather is SET's Automated Radiation Measurements for Aerospace Safety (ARMAS) system. ARMAS will provide the "weather" of the radiation environment to improve aircraft crew and passenger safety. Through several dozen flights the ARMAS project has successfully demonstrated the operation of a micro dosimeter on commercial aviation altitude aircraft that captures the real-time radiation environment resulting from Galactic Cosmic Rays and Solar Energetic Particles. The real-time radiation exposure is computed as an effective dose rate (body-averaged over the radiative-sensitive organs and tissues in units of microsieverts per hour); total ionizing dose is captured on the aircraft, downlinked in real-time via Iridium satellites, processed on the ground into effective dose rates, compared with NASA's Langley Research Center (LaRC) most recent Nowcast of Atmospheric Ionizing Radiation System (NAIRAS) global radiation climatology model runs, and then made available to end users via the web and smart phone apps. We are extending the dose measurement domain above commercial aviation altitudes into the stratosphere with a collaborative project organized by NASA's Armstrong Flight Research Center (AFRC) called Upper-atmospheric Space and Earth Weather eXperiment (USEWX). In USEWX we will be flying on the ER-2 high altitude aircraft a micro dosimeter for

  11. Estimation of radiation dose received by the radiation worker during F-18 FDG injection process

    PubMed Central

    Jha, Ashish Kumar; Zade, Anand; Rangarajan, Venkatesh

    2011-01-01

    Background: The radiation dosimetric literature concerning the medical and non-medical personnel working in nuclear medicine departments are limited, particularly radiation doses received by radiation worker in nuclear medicine department during positron emission tomography (PET) radiopharmaceutical injection process. This is of interest and concern for the personnel. Aim: To measure the radiation dose received by the staff involved in injection process of Fluorine-18 Fluorodeoxyglucose (FDG). Materials and Methods: The effective whole body doses to the radiation workers involved in injections of 1511 patients over a period of 10 weeks were evaluated using pocket dosimeter. Each patient was injected with 5 MBq/kg of F-18 FDG. The F18-FDG injection protocol followed in our department is as follows. The technologist dispenses the dose to be injected and records the pre-injection activity. The nursing staff members then secure an intravenous catheter. The nuclear medicine physicians/residents inject the dose on a rotation basis in accordance with ALARA principle. After the injection of the tracer, the nursing staff members flush the intravenous catheter. The person who injected the tracer then measures the post-injection residual dose in the syringe. Results: The mean effective whole body doses per injection for the staff were the following: Nurses received 1.44±0.22 μSv/injection (3.71±0.48 nSv/MBq), for doctors the dose values were 2.44±0.25 μSv/injection (6.29±0.49 nSv/MBq) and for technologists the doses were 0.61±0.10 μSv/injection (1.58±0.21 nSv/MBq). It was seen that the mean effective whole body dose per injection of our positron emission tomography/computed tomography (PET/CT) staff who were involved in the F18-FDG injection process was maximum for doctors (54.34% differential doses), followed by nurses (32.02% differential doses) and technologist (13.64% differential doses). Conclusion: This study confirms that low levels of radiation dose are

  12. Radiation pneumonitis following large single dose irradiation: a re-evaluation based on absolute dose to lung

    SciTech Connect

    Van Dyk, J.; Keane, T.J.; Kan, S.; Rider, W.D.; Fryer, C.J.H.

    1981-04-01

    The acute radiation pneumonitis syndrome is a major complication for patients receiving total thoracic irradiation in a large single dose. Previous studies have evaluated the onset of radiation pneumonitis on the basis of radiation doses calculated assuming unit density tissues. In this report, the incidence of radiation pneumonitis is determined as a function of absolute dose to lung. A simple algorithm relating dose correction factor to anterior-posterior patient diameter has been derived using a CT-aided treatment planning system. This algorithm was used to determine, retrospectively, the dose to lung for a group of 303 patients who had been treated with large field irradiation techniques. Of this group, 150 patients had no previous lung disease and had virtually no additional lung irradiation prior or subsequent to their large field treatment. The actuarial incidence of radiation pneumonitis versus dose to lung was evaluated using a simplified probit analysis. The resultant best fit sigmoidal complication curve demonstrates the onset of radiation pneumonitis to occur at about 750 rad with the 5% actuarial incidence occurring at approximately 820 rad. The errors associated with the dose determination procedure as well as the actuarial incidence calculations are considered. The time of onset of radiation pneumonitis occurs between 1 to 7 months after irradiation for 90% of the patients who developed pneumonitis with the peak incidence occurring at 2 at 3 months. No correlation was found between time of onset and the dose to lung over a dose range of 650 to 1250 rad.

  13. Radiation doses to staff in a department of nuclear medicine.

    PubMed

    Harbottle, E A; Parker, R P; Davis, R

    1976-07-01

    A survey of data concerning radiation protection of staff working in the Nuclear Medicine Department and associated sections of the Physics Department at the Royal Marsden Hospital (Surrey Branch) is given for the period 1972 to 1975 inclusive. Results of routine film monitoring and whole-body counting are presented. Additional film monitors were used to check working areas, finger doses and any discrepancies between doses to the upper and lower trunk of personnel. In general, exposure to staff in the Nuclear Medicine Department is below 220 mrad per person per year, and below 1,000 mrad per person per year in the Radioisotope Dispensary. The dose received by radiographers is primarily due to spending time close to patients. Since about 5,000 intravenous injections of radionuclides are given each year in our department, the resulting finger doses to the staff involved may give rise to concern unless the task is shared. PMID:824004

  14. The effect of radiation dose on mouse skeletal muscle remodeling

    PubMed Central

    Hardee, Justin P.; Puppa, Melissa J.; Fix, Dennis K.; Gao, Song; Hetzler, Kimbell L.; Bateman, Ted A.; Carson, James A.

    2014-01-01

    Background The purpose of this study was to determine the effect of two clinically relevant radiation doses on the susceptibility of mouse skeletal muscle to remodeling. Materials and methods. Alterations in muscle morphology and regulatory signaling were examined in tibialis anterior and gastrocnemius muscles after radiation doses that differed in total biological effective dose (BED). Female C57BL/6 (8-wk) mice were randomly assigned to non-irradiated control, four fractionated doses of 4 Gy (4x4 Gy; BED 37 Gy), or a single 16 Gy dose (16 Gy; BED 100 Gy). Mice were sacrificed 2 weeks after the initial radiation exposure. Results The 16 Gy, but not 4x4 Gy, decreased total muscle protein and RNA content. Related to muscle regeneration, both 16 Gy and 4x4 Gy increased the incidence of central nuclei containing myofibers, but only 16 Gy increased the extracellular matrix volume. However, only 4x4 Gy increased muscle 4-hydroxynonenal expression. While both 16 Gy and 4x4 Gy decreased IIB myofiber mean cross-sectional area (CSA), only 16 Gy decreased IIA myofiber CSA. 16 Gy increased the incidence of small diameter IIA and IIB myofibers, while 4x4 Gy only increased the incidence of small diameter IIB myofibers. Both treatments decreased the frequency and CSA of low succinate dehydrogenase activity (SDH) fibers. Only 16 Gy increased the incidence of small diameter myofibers having high SDH activity. Neither treatment altered muscle signaling related to protein turnover or oxidative metabolism. Conclusions Collectively, these results demonstrate that radiation dose differentially affects muscle remodeling, and these effects appear to be related to fiber type and oxidative metabolism. PMID:25177239

  15. PET/CT-guided Interventions: Personnel Radiation Dose

    SciTech Connect

    Ryan, E. Ronan Thornton, Raymond; Sofocleous, Constantinos T.; Erinjeri, Joseph P.; Hsu, Meier; Quinn, Brian; Dauer, Lawrence T.; Solomon, Stephen B.

    2013-08-01

    PurposeTo quantify radiation exposure to the primary operator and staff during PET/CT-guided interventional procedures.MethodsIn this prospective study, 12 patients underwent PET/CT-guided interventions over a 6 month period. Radiation exposure was measured for the primary operator, the radiology technologist, and the nurse anesthetist by means of optically stimulated luminescence dosimeters. Radiation exposure was correlated with the procedure time and the use of in-room image guidance (CT fluoroscopy or ultrasound).ResultsThe median effective dose was 0.02 (range 0-0.13) mSv for the primary operator, 0.01 (range 0-0.05) mSv for the nurse anesthetist, and 0.02 (range 0-0.05) mSv for the radiology technologist. The median extremity dose equivalent for the operator was 0.05 (range 0-0.62) mSv. Radiation exposure correlated with procedure duration and with the use of in-room image guidance. The median operator effective dose for the procedure was 0.015 mSv when conventional biopsy mode CT was used, compared to 0.06 mSv for in-room image guidance, although this did not achieve statistical significance as a result of the small sample size (p = 0.06).ConclusionThe operator dose from PET/CT-guided procedures is not significantly different than typical doses from fluoroscopically guided procedures. The major determinant of radiation exposure to the operator from PET/CT-guided interventional procedures is time spent in close proximity to the patient.

  16. Monte Carlo dose enhancement studies in microbeam radiation therapy

    SciTech Connect

    Martinez-Rovira, I.; Prezado, Y.

    2011-07-15

    Purpose: A radical radiation therapy treatment for gliomas requires extremely high absorbed doses resulting in subsequent deleterious side effects in healthy tissue. Microbeam radiation therapy (MRT) is an innovative technique based on the fact that normal tissue can withstand high radiation doses in small volumes without any significant damage. The synchrotron-generated x-ray beam is collimated and delivered to an array of narrow micrometer-sized planar rectangular fields. Several preclinical experiments performed at the Brookhaven National Laboratory (BNL) and at the European Synchrotron Radiation Facility (ESRF) confirmed that MRT yields a higher therapeutic index than nonsegmented beams of the same characteristics. This index can be greatly improved by loading the tumor with high atomic number (Z) contrast agents. The aim of this work is to find the high-Z element that provides optimum dose enhancement. Methods: Monte Carlo simulations (PENELOPE/penEasy) were performed to assess the peak and valley doses as well as their ratio (PVDR) in healthy tissue and in the tumor, loaded with different contrast agents. The optimization criteria used were maximization of the ratio between the PVDR values in healthy tissue respect to the PVDR in the tumor and minimization of bone and brain valley doses. Results: Dose enhancement factors, PVDR, and valley doses were calculated for different high-Z elements. A significant decrease of PVDR values in the tumor, accompanied by a gain in the valley doses, was found in the presence of high-Z elements. This enables the deposited dose in the healthy tissue to be reduced. The optimum high-Z element depends on the irradiation configuration. As a general trend, the best outcome is provided by the highest Z contrast agents considered, i.e., gold and thallium. However, lanthanides (especially Lu) and hafnium also offer a satisfactory performance. Conclusions: The remarkable therapeutic index in microbeam radiation therapy can be further

  17. Methionine Uptake and Required Radiation Dose to Control Glioblastoma

    SciTech Connect

    Iuchi, Toshihiko; Hatano, Kazuo; Uchino, Yoshio; Itami, Makiko; Hasegawa, Yuzo; Kawasaki, Koichiro; Sakaida, Tsukasa; Hara, Ryusuke

    2015-09-01

    Purpose: The purpose of this study was to retrospectively assess the feasibility of radiation therapy planning for glioblastoma multiforme (GBM) based on the use of methionine (MET) positron emission tomography (PET), and the correlation among MET uptake, radiation dose, and tumor control. Methods and Materials: Twenty-two patients with GBM who underwent MET-PET prior to radiation therapy were enrolled. MET uptake in 30 regions of interest (ROIs) from 22 GBMs, biologically effective doses (BEDs) for the ROIs and their ratios (MET uptake:BED) were compared in terms of whether the ROIs were controlled for >12 months. Results: MET uptake was significantly correlated with tumor control (odds ratio [OR], 10.0; P=.005); however, there was a higher level of correlation between MET uptake:BED ratio and tumor control (OR, 40.0; P<.0001). These data indicated that the required BEDs for controlling the ROIs could be predicted in terms of MET uptake; BED could be calculated as [34.0 × MET uptake] Gy from the optimal threshold of the MET uptake:BED ratio for tumor control. Conclusions: Target delineation based on MET-PET was demonstrated to be feasible for radiation therapy treatment planning. MET-PET could not only provide precise visualization of infiltrating tumor cells but also predict the required radiation doses to control target regions.

  18. Comparative transcriptome analysis of rice seedlings induced by different doses of heavy ion radiation

    NASA Astrophysics Data System (ADS)

    Zhao, Qian; Sun, Yeqing; Wang, Wei

    2016-07-01

    Highly ionizing radiation (HZE) in space is considered as a main factor causing biological effects on plant seeds. To investigate the different effects on genome-wide gene expression of low-dose and high-dose ion radiation, we carried out ground-base carbon particle HZE experiments with different cumulative doses (0Gy, 0.2Gy, 2Gy) to rice seeds and then performed comparative transcriptome analysis of the rice seedlings. We identified a total of 2551 and 1464 differentially expressed genes (DEGs) in low-dose and high-dose radiation groups, respectively. Gene ontology analyses indicated that low-dose and high-dose ion radiation both led to multiple physiological and biochemical activities changes in rice. By Gene Ontology analyses, the results showed that only one process-oxidation reduction process was enriched in the biological process category after high-dose ion radiation, while more processes such as response to biotic stimulus, heme binding, tetrapyrrole binding, oxidoreductase activity, catalytic activity and oxidoreductase activity were significantly enriched after low-dose ion radiation. The results indicated that the rice plants only focused on the process of oxidation reduction to response to high-dose ion radiation, whereas it was a coordination of multiple biological processes to response to low-dose ion radiation. To elucidate the transcriptional regulation of radiation stress-responsive genes, we identified several DEGs-encoding TFs. AP2/EREBP, bHLH, C2H2, MYB and WRKY TF families were altered significantly in response to ion radiation. Mapman analysis speculated that the biological effects on rice seedlings caused by the radiation stress might share similar mechanisms with the biotic stress. Our findings highlight important alterations in the expression of radiation response genes, metabolic pathways, and TF-encoding genes in rice seedlings exposed to low-dose and high-dose ion radiation.

  19. Radiation doses from computed tomography practice in Johor Bahru, Malaysia

    NASA Astrophysics Data System (ADS)

    Karim, M. K. A.; Hashim, S.; Bradley, D. A.; Bakar, K. A.; Haron, M. R.; Kayun, Z.

    2016-04-01

    Radiation doses for Computed Tomography (CT) procedures have been reported, encompassing a total of 376 CT examinations conducted in one oncology centre (Hospital Sultan Ismail) and three diagnostic imaging departments (Hospital Sultanah Aminah, Hospital Permai and Hospital Sultan Ismail) at Johor hospital's. In each case, dose evaluations were supported by data from patient questionnaires. Each CT examination and radiation doses were verified using the CT EXPO (Ver. 2.3.1, Germany) simulation software. Results are presented in terms of the weighted computed tomography dose index (CTDIw), dose length product (DLP) and effective dose (E). The mean values of CTDIw, DLP and E were ranged between 7.6±0.1 to 64.8±16.5 mGy, 170.2±79.2 to 943.3±202.3 mGy cm and 1.6±0.7 to 11.2±6.5 mSv, respectively. Optimization techniques in CT are suggested to remain necessary, with well-trained radiology personnel remaining at the forefront of such efforts.

  20. APS undulator radiation: First results

    SciTech Connect

    Cai, Z.; Dejus, R.J.; Hartog, P.D.

    1995-12-31

    The first undulator radiation has been extracted from the Advanced Photon Source (APS). The results from the characterization of this radiation are very satisfactory. With the undulator set at a gap of 15.8 mm (K=1.61), harmonics as high as the 17th were observed using a crystal spectrometer. The angular distribution of the third-harmonic radiation was measured, and the source was imaged using a zone plate to determine the particle beam emittance. The horizontal beam emittance was found to be 6.9 {plus_minus} 1.0 nm-rad, and the vertical emittance coupling was found to be less than 3%. The absolute spectral flux was measured over a wide range of photon energies, and it agrees remarkably well with the theoretical calculations based on the measured undulator magnetic field profile and the measured beam emittance. These results indicate that both the emittance of the electron beam and the undulator magnetic field quality exceed the original specifications.

  1. Radiation Dose Estimation for Pediatric Patients Undergoing Cardiac Catheterization

    NASA Astrophysics Data System (ADS)

    Wang, Chu

    Patients undergoing cardiac catheterization are potentially at risk of radiation-induced health effects from the interventional fluoroscopic X-ray imaging used throughout the clinical procedure. The amount of radiation exposure is highly dependent on the complexity of the procedure and the level of optimization in imaging parameters applied by the clinician. For cardiac catheterization, patient radiation dosimetry, for key organs as well as whole-body effective, is challenging due to the lack of fixed imaging protocols, unlike other common X-ray based imaging modalities. Pediatric patients are at a greater risk compared to adults due to their greater cellular radio-sensitivities as well as longer remaining life-expectancy following the radiation exposure. In terms of radiation dosimetry, they are often more challenging due to greater variation in body size, which often triggers a wider range of imaging parameters in modern imaging systems with automatic dose rate modulation. The overall objective of this dissertation was to develop a comprehensive method of radiation dose estimation for pediatric patients undergoing cardiac catheterization. In this dissertation, the research is divided into two main parts: the Physics Component and the Clinical Component. A proof-of-principle study focused on two patient age groups (Newborn and Five-year-old), one popular biplane imaging system, and the clinical practice of two pediatric cardiologists at one large academic medical center. The Physics Component includes experiments relevant to the physical measurement of patient organ dose using high-sensitivity MOSFET dosimeters placed in anthropomorphic pediatric phantoms. First, the three-dimensional angular dependence of MOSFET detectors in scatter medium under fluoroscopic irradiation was characterized. A custom-made spherical scatter phantom was used to measure response variations in three-dimensional angular orientations. The results were to be used as angular dependence

  2. Coaching Reduced the Radiation Dose of Pain Physicians by Half during Interventional Procedures.

    PubMed

    Slegers, A S; Gültuna, I; Aukes, J A; van Gorp, E J J A A; Blommers, F M N; Niehof, S P; Bosman, J

    2015-06-01

    The increased use of C-arm fluoroscopy in interventional pain management has led to higher radiation exposure for pain physicians. This study investigated whether or not real-time radiation dose feedback with coaching can reduce the scatter dose received by pain physicians. Firstly, phantom measurements were made to create a scatter dose profile, which visualizes the average scatter radiation for different C-arm positions at 3 levels of height. Secondly, in the clinical part, the radiation dose received by pain physicians during pain treatment procedures was measured real-time to evaluate (1) the effect of real-time dose feedback on the received scatter dose, and (2) the effect of knowledge of the scatter dose profile and active coaching, on the scatter dose received by the pain physician. The clinical study included 330 interventional pain procedures. The results showed that real-time feedback of the received dose did not lead to a reduction in scatter radiation. However, visualization of the scatter dose in a scatter dose profile and active coaching on optimal positions did reduce the scatter radiation received by pain physicians during interventional pain procedures by 46.4% (P = 0.05). Knowledge of and real-time coaching with the scatter dose profile reduced the dose of pain physicians by half, caused by their increased awareness for scatter radiation and their insight into strategic positioning. PMID:25354342

  3. Contribution of maternal radionuclide burdens to prenatal radiation doses

    SciTech Connect

    Sikov, M.R.; Hui, T.E.

    1996-05-01

    This report describes approaches to calculating and expressing radiation doses to the embryo/fetus from internal radionuclides. Information was obtained for selected, occupationally significant radioelements that provide a spectrum of metabolic and dosimetric characteristics. Evaluations are also presented for inhaled inert gases and for selected radiopharmaceuticals. Fractional placental transfer and/or ratios of concentration in the embryo/fetus to that in the woman were calculated for these materials. The ratios were integrated with data from biokinetic transfer models to estimate radioactivity levels in the embryo/fetus as a function of stage of pregnancy and time after entry into the transfer compartment or blood of the pregnant woman. These results are given as tables of deposition and retention in the embryo/fetus as a function of gestational age at exposure and elapsed time following exposure. Methodologies described by MIRD were extended to formalize and describe details for calculating radiation absorbed doses to the embryo/fetus. Calculations were performed using a model situation that assumed a single injection of 1 {mu}Ci into a woman`s blood; independent calculations were performed for administration at successive months of pregnancy. Gestational -stage-dependent dosimetric tabulations are given together with tables of correlations and relationships. Generalized surrogate dose factors and categorizations are provided in the report to provide for use in operational radiological protection situations. These approaches to calculation yield radiation absorbed doses that can be converted to dose equivalent by multiplication by quality factor. Dose equivalent is the most common quantity for stating prenatal dose limits in the United States and is appropriate for the types of effect that are usually associated with prenatal exposure. If it is desired to obtain alternatives for other purposes, this value can be multiplied by appropriate weighting factors.

  4. Austrian results from Matroshka poncho and organ dose determination

    NASA Astrophysics Data System (ADS)

    Hajek, M.; Bergmann, R.; Fugger, M.; Vana, N.

    Cosmic rays in low-earth orbits LEO primarily consist of high-energy charged particles originating from galactic cosmic radiation GCR energetic solar particle events SPE and trapped radiation belts These radiations of high linear energy transfer LET generally inflict greater biological damage than that resulting from typical terrestrial radiation hazards Particle and energy spectra are attenuated in interaction processes within shielding structures and within the human body Reliable assessment of health risks to astronaut crews is pivotal in the design of future expeditions into interplanetary space and requires knowledge of absorbed radiation doses in critical radiosensitive organs and tissues The European Space Agency ESA Matroshka experiment---conducted under the aegis of the German Aerospace Center DLR ---is aimed at simulating an astronaut s body during extravehicular activities EVA Matroshka basically consists of a human phantom torso attached to a base structure and covered with a protective carbon-fibre container acting as a spacesuit model The phantom is divided into 33 tissue-equivalent polyurethane slices of specific density for tissue and organs Natural bones are embedded Channels and cut-outs enable accommodation of active and passive radiation monitors The torso is dressed by a skin-equivalent poncho which is also designed for dosimeter integration The phantom houses in total 7 active and more than 6000 passive radiation sensors Thereof the Atomic Institute of the Austrian Universities ATI provided more than

  5. Risk of cancer subsequent to low-dose radiation

    SciTech Connect

    Warren, S.

    1980-01-01

    The author puts low dose irradiation risks in perspective using average background radiation doses for standards. He assailed irresponsible media coverage during the height of public interest in the Three-Mile Island Reactor incident. (PCS)

  6. Increased occupational radiation doses: nuclear fuel cycle.

    PubMed

    Bouville, André; Kryuchkov, Victor

    2014-02-01

    The increased occupational doses resulting from the Chernobyl nuclear reactor accident that occurred in Ukraine in April 1986, the reactor accident of Fukushima that took place in Japan in March 2011, and the early operations of the Mayak Production Association in Russia in the 1940s and 1950s are presented and discussed. For comparison purposes, the occupational doses due to the other two major reactor accidents (Windscale in the United Kingdom in 1957 and Three Mile Island in the United States in 1979) and to the main plutonium-producing facility in the United States (Hanford Works) are also covered but in less detail. Both for the Chernobyl nuclear reactor accident and the routine operations at Mayak, the considerable efforts made to reconstruct individual doses from external irradiation to a large number of workers revealed that the recorded doses had been overestimated by a factor of about two.Introduction of Increased Occupational Exposures: Nuclear Industry Workers. (Video 1:32, http://links.lww.com/HP/A21). PMID:24378501

  7. Monitoring of radiation dose rates around a clinical nuclear medicine site

    NASA Astrophysics Data System (ADS)

    Shao, Chia-Ho; Lu, Cheng-Chang; Chen, Tou-Rong; Weng, Jui-Hung; Kao, Pan-Fu; Dong, Shang-Lung; Chou, Ming-Jen

    2014-11-01

    The monitoring of radiation dose around the nuclear medicine site is an important study issue. In this study, TLD-100H radiation dosimeters were used to measure the ambient radiation dose rates around a clinical nuclear medicine site in order to investigate the latent hot zones of radiation exposure. Results of this study showed that the radiation doses measured from all piping and storage systems were comparable to the background dose. A relatively high dose was observed at the single bend point of waste water piping of the PET/CT. Another important finding was the unexpected high dose rates observed at the non-restricted waiting area (NRWA) of SPECT. To conclude, this study provides useful information for further determination of an appropriate dose reduction strategy to achieve the ALARA principle in a clinical nuclear medicine site.

  8. Measurement and assessment of radiation dose of astronauts in space

    NASA Astrophysics Data System (ADS)

    Zhang, Binquan; Sun, Yue-qiang; Yang, Chuibai; Zhang, Shenyi; Liang, Jinbao

    Astronauts in flight are exposed by the space radiation, which is mainly composed of proton, electron, heavy ion, and neutron. To assess the radiation risk, measurement and assessment of radiation dose of astronauts is indispensable. Especially, measurement for heavy ion radiation is most important as it contributes the major dose. Until now, most of the measurements and assessments of radiation dose of astronauts are based on the LET (Linear Energy Transfer) spectrum of space radiation. However, according to the ICRP Publication 123, energy and charge number of heavy ions should be measured in order to assess space radiation exposure to astronauts. In addition, from the publication, quality factors for each organs or tissues of astronauts are different and they should be calculated or measured independently. Here, a method to measure the energy and charge number of heavy ion and a voxel phantom based on the anatomy of Chinese adult male are presented for radiation dose assessment of astronauts.

  9. Radiation-Induced Leukemia at Doses Relevant to Radiation Therapy: Modeling Mechanisms and Estimating Risks

    NASA Technical Reports Server (NTRS)

    Shuryak, Igor; Sachs, Rainer K.; Hlatky, Lynn; Mark P. Little; Hahnfeldt, Philip; Brenner, David J.

    2006-01-01

    Because many cancer patients are diagnosed earlier and live longer than in the past, second cancers induced by radiation therapy have become a clinically significant issue. An earlier biologically based model that was designed to estimate risks of high-dose radiation induced solid cancers included initiation of stem cells to a premalignant state, inactivation of stem cells at high radiation doses, and proliferation of stem cells during cellular repopulation after inactivation. This earlier model predicted the risks of solid tumors induced by radiation therapy but overestimated the corresponding leukemia risks. Methods: To extend the model to radiation-induced leukemias, we analyzed in addition to cellular initiation, inactivation, and proliferation a repopulation mechanism specific to the hematopoietic system: long-range migration through the blood stream of hematopoietic stem cells (HSCs) from distant locations. Parameters for the model were derived from HSC biologic data in the literature and from leukemia risks among atomic bomb survivors v^ ho were subjected to much lower radiation doses. Results: Proliferating HSCs that migrate from sites distant from the high-dose region include few preleukemic HSCs, thus decreasing the high-dose leukemia risk. The extended model for leukemia provides risk estimates that are consistent with epidemiologic data for leukemia risk associated with radiation therapy over a wide dose range. For example, when applied to an earlier case-control study of 110000 women undergoing radiotherapy for uterine cancer, the model predicted an excess relative risk (ERR) of 1.9 for leukemia among women who received a large inhomogeneous fractionated external beam dose to the bone marrow (mean = 14.9 Gy), consistent with the measured ERR (2.0, 95% confidence interval [CI] = 0.2 to 6.4; from 3.6 cases expected and 11 cases observed). As a corresponding example for brachytherapy, the predicted ERR of 0.80 among women who received an inhomogeneous low-dose

  10. Low-dose radiation exposure induces a HIF-1-mediated adaptive and protective metabolic response

    PubMed Central

    Lall, R; Ganapathy, S; Yang, M; Xiao, S; Xu, T; Su, H; Shadfan, M; Asara, J M; Ha, C S; Ben-Sahra, I; Manning, B D; Little, J B; Yuan, Z-M

    2014-01-01

    Because of insufficient understanding of the molecular effects of low levels of radiation exposure, there is a great uncertainty regarding its health risks. We report here that treatment of normal human cells with low-dose radiation induces a metabolic shift from oxidative phosphorylation to aerobic glycolysis resulting in increased radiation resistance. This metabolic change is highlighted by upregulation of genes encoding glucose transporters and enzymes of glycolysis and the oxidative pentose phosphate pathway, concomitant with downregulation of mitochondrial genes, with corresponding changes in metabolic flux through these pathways. Mechanistically, the metabolic reprogramming depends on HIF1α, which is induced specifically by low-dose irradiation linking the metabolic pathway with cellular radiation dose response. Increased glucose flux and radiation resistance from low-dose irradiation are also observed systemically in mice. This highly sensitive metabolic response to low-dose radiation has important implications in understanding and assessing the health risks of radiation exposure. PMID:24583639

  11. Measurement of three-dimensional radiation dose distributions using MRI.

    PubMed

    Prasad, P V; Nalcioglu, O; Rabbani, B

    1991-10-01

    Recent investigations have shown that nuclear magnetic resonance (NMR) can be used in conjunction with a suitable chemical dosimeter to estimate the dose from ionizing radiation (Gore et al., Phys Med. Biol. 29, 1189-1197, 1984). Based on this fact it was proposed that spatial dose distributions can be measured in gels infused with the chemical dosimeter using NMR imaging. There have been few such attempts and they provided only qualitative results. In this paper, we report results demonstrating the feasibility of obtaining quantitative dose distribution measurements by this technique. It is shown that quantitative dose distribution measurements necessitate the calculation of relaxation rate maps. We have determined that the spin-spin relaxation rate is a more sensitive parameter than the spin-lattice relaxation rate. It is also demonstrated that the addition of chemical sensitizers could improve the dose sensitivity of the measured NMR parameters. The two features characterizing a photon beam, depth-dose relationship, and beam profile as measured by this technique are in good agreement with the measurements using conventional methods, ionization chambers, and film dosimetry. PMID:1924718

  12. The Inhibitory Effects of Low-Dose Ionizing Radiation in IgE-Mediated Allergic Responses

    PubMed Central

    Nam, Seon Young; Yang, Kwang Hee; Kim, Cha Soon; Lee, In Kyung; Kim, Ji Young

    2015-01-01

    Ionizing radiation has different biological effects according to dose and dose rate. In particular, the biological effect of low-dose radiation is unclear. Low-dose whole-body gamma irradiation activates immune responses in several ways. However, the effects and mechanism of low-dose radiation on allergic responses remain poorly understood. Previously, we reported that low-dose ionizing radiation inhibits mediator release in IgE-mediated RBL-2H3 mast cell activation. In this study, to have any physiological relevance, we investigated whether low-dose radiation inhibits allergic responses in activated human mast cells (HMC-1(5C6) and LAD2 cells), mouse models of passive cutaneous anaphylaxis and the late-phase cutaneous response. High-dose radiation induced cell death, but low-dose ionizing radiation of <0.5 Gy did not induce mast cell death. Low-dose ionizing radiation that did not induce cell death significantly suppressed mediator release from human mast cells (HMC-1(5C6) and LAD2 cells) that were activated by antigen-antibody reaction. To determine the inhibitory mechanism of mediator released by low-dose ionizing radiation, we examined the phosphorylation of intracellular signaling molecules such as Lyn, Syk, phospholipase Cγ, and protein kinase C, as well as the intracellular free Ca2+ concentration ([Ca2+]i). The phosphorylation of signaling molecules and [Ca2+]i following stimulation of FcεRI receptors was inhibited by low dose ionizing radiation. In agreement with its in vitro effect, ionizing radiation also significantly inhibited inflammatory cells infiltration, cytokine mRNA expression (TNF-α, IL-4, IL-13), and symptoms of passive cutaneous anaphylaxis reaction and the late-phase cutaneous response in anti-dinitrophenyl IgE-sensitized mice. These results indicate that ionizing radiation inhibits both mast cell-mediated immediate- and delayed-type allergic reactions in vivo and in vitro. PMID:26317642

  13. The Inhibitory Effects of Low-Dose Ionizing Radiation in IgE-Mediated Allergic Responses.

    PubMed

    Joo, Hae Mi; Kang, Su Jin; Nam, Seon Young; Yang, Kwang Hee; Kim, Cha Soon; Lee, In Kyung; Kim, Ji Young

    2015-01-01

    Ionizing radiation has different biological effects according to dose and dose rate. In particular, the biological effect of low-dose radiation is unclear. Low-dose whole-body gamma irradiation activates immune responses in several ways. However, the effects and mechanism of low-dose radiation on allergic responses remain poorly understood. Previously, we reported that low-dose ionizing radiation inhibits mediator release in IgE-mediated RBL-2H3 mast cell activation. In this study, to have any physiological relevance, we investigated whether low-dose radiation inhibits allergic responses in activated human mast cells (HMC-1(5C6) and LAD2 cells), mouse models of passive cutaneous anaphylaxis and the late-phase cutaneous response. High-dose radiation induced cell death, but low-dose ionizing radiation of <0.5 Gy did not induce mast cell death. Low-dose ionizing radiation that did not induce cell death significantly suppressed mediator release from human mast cells (HMC-1(5C6) and LAD2 cells) that were activated by antigen-antibody reaction. To determine the inhibitory mechanism of mediator released by low-dose ionizing radiation, we examined the phosphorylation of intracellular signaling molecules such as Lyn, Syk, phospholipase Cγ, and protein kinase C, as well as the intracellular free Ca2+ concentration ([Ca2+]i). The phosphorylation of signaling molecules and [Ca2+]i following stimulation of FcεRI receptors was inhibited by low dose ionizing radiation. In agreement with its in vitro effect, ionizing radiation also significantly inhibited inflammatory cells infiltration, cytokine mRNA expression (TNF-α, IL-4, IL-13), and symptoms of passive cutaneous anaphylaxis reaction and the late-phase cutaneous response in anti-dinitrophenyl IgE-sensitized mice. These results indicate that ionizing radiation inhibits both mast cell-mediated immediate- and delayed-type allergic reactions in vivo and in vitro. PMID:26317642

  14. Evaluation of Radiation Dose Effects on Rat Bones Using Synchrotron Radiation Computed Microtomography

    SciTech Connect

    Nogueira, Liebert Parreiras; Braz, Delson

    2011-12-13

    In this work, we investigated the consequences of irradiation in the femora and ribs of rats submitted to radiation doses of 5 Gy. Three different sites in femur specimens (head, distal metaphysis and distal epiphysis) and one in ribs (ventral) were imaged using synchrotron radiation microcomputed tomography to assess trabecular bone microarchitecture. Histomorphometric quantification was calculated directly from the 3D microtomographic images using synchrotron radiation. The 3D microtomographic images were obtained at the SYRMEP (SYnchrotron Radiation for MEdical Physics) beamline at the Elettra Synchrotron Laboratory in Trieste, Italy. A better understanding of the biological interactions that occur after exposure to photon radiation is needed in order to optimize therapeutic regimens and facilitate development and strategies that decrease radiation-induced side effects in humans. Results showed significant differences between irradiated and non-irradiated specimens, mostly in head and distal metaphysis bone sites.

  15. Radiation dose reduction in pediatric abdominal CT scanning

    SciTech Connect

    Kamel, I.R.

    1993-01-01

    A clinical trial was designed to test whether a significantly lower radiation dose technique could be used for pediatric abdominal CT scanning without loss of diagnostic image quality. The study included pediatric patients referred to radiology from the Children's Hospital and clinics at The University of Michigan. Seventy-eight cases were included in the study, 36 cases in the experimental group and 42 in the control group. Patient characteristics in both groups were comparable in every respect except for the technical factors used to expose the pelvis. Patients in the experimental group were scanned with a technique using 80 mAs while those in the control group were scanned with the conventional technique of 240 mAs. Therefore, the radiation dose to the pelvis was three times higher in the control group than in the experimental group. Scans were evaluated by two experienced pediatric radiologists who assessed anatomical details, image resolution and the degree of confidence in reaching a diagnosis. The low-mAs technique did not result in reduction of diagnostic image quality or the confidence in reaching a diagnosis. In conclusion, the radiation dose resulting from pediatric CT of the pelvis may be reduced by a factor of three with equivalent medical benefit.

  16. RADIANCE: An automated, enterprise-wide solution for archiving and reporting CT radiation dose estimates.

    PubMed

    Cook, Tessa S; Zimmerman, Stefan L; Steingall, Scott R; Maidment, Andrew D A; Kim, Woojin; Boonn, William W

    2011-01-01

    There is growing interest in the ability to monitor, track, and report exposure to radiation from medical imaging. Historically, however, dose information has been stored on an image-based dose sheet, an arrangement that precludes widespread indexing. Although scanner manufacturers are beginning to include dose-related parameters in the Digital Imaging and Communications in Medicine (DICOM) headers of imaging studies, there remains a vast repository of retrospective computed tomographic (CT) data with image-based dose sheets. Consequently, it is difficult for imaging centers to monitor their dose estimates or participate in the American College of Radiology (ACR) Dose Index Registry. An automated extraction software pipeline known as Radiation Dose Intelligent Analytics for CT Examinations (RADIANCE) has been designed that quickly and accurately parses CT dose sheets to extract and archive dose-related parameters. Optical character recognition of information in the dose sheet leads to creation of a text file, which along with the DICOM study header is parsed to extract dose-related data. The data are then stored in a relational database that can be queried for dose monitoring and report creation. RADIANCE allows efficient dose analysis of CT examinations and more effective education of technologists, radiologists, and referring physicians regarding patient exposure to radiation at CT. RADIANCE also allows compliance with the ACR's dose reporting guidelines and greater awareness of patient radiation dose, ultimately resulting in improved patient care and treatment. PMID:21969661

  17. Ionizing Radiation Dose Due to the Use of Agricultural Fertilizers

    SciTech Connect

    Umisedo, Nancy K.; Okuno, Emico; Medina, Nilberto H.; Colacioppo, Sergio; Hiodo, Francisco Y.

    2008-08-07

    The transference of radionuclides from the fertilizers to/and from soils to the foodstuffs can represent an increment in the internal dose when the vegetables are consumed by the human beings. This work evaluates the contribution of fertilizers to the increase of radiation level in the environment and of dose to the people. Samples of fertilizers, soils and vegetables produced in farms located in the neighbourhood of Sao Paulo city in the State of Sao Paulo, Brazil were analysed through gamma spectroscopy. The values of specific activity of {sup 40}K, {sup 238}U and {sup 232}Th show that there is no significant transference of natural radionuclides from fertilizers to the final product of the food chain. The annual committed effective dose due to the ingestion of {sup 40}K contained in the group of consumed vegetables analysed in this work resulted in the very low value of 0.882 {mu}Sv.

  18. Clinically Relevant Doses of Enalapril Mitigate Multiple Organ Radiation Injury.

    PubMed

    Cohen, Eric P; Fish, Brian L; Moulder, John E

    2016-03-01

    Angiotensin-converting enzyme inhibitors (ACEi) are effective mitigators of radiation nephropathy. To date, their experimental use has been in fixed-dose regimens. In clinical use, doses of ACEi and other medication may be escalated to achieve greater benefit. We therefore used a rodent model to test the ACEi enalapril as a mitigator of radiation injury in an escalating-dose regimen. Single-fraction partial-body irradiation (PBI) with one hind limb out of the radiation field was used to model accidental or belligerent radiation exposures. PBI doses of 12.5, 12.75 and 13 Gy were used to establish multi-organ injury. One third of the rats underwent PBI alone, and two thirds of the rats had enalapril started five days after PBI at a dose of 30 mg/l in the drinking water. When there was established azotemic renal injury enalapril was escalated to a 60 mg/l dose in half of the animals and then later to a 120 mg/l dose. Irradiated rats on enalapril had significant mitigation of combined pulmonary and renal morbidity and had significantly less azotemia. Dose escalation of enalapril did not significantly improve outcomes compared to fixed-dose enalapril. The current data support use of the ACEi enalapril at a fixed and clinically usable dose to mitigate radiation injury after partial-body radiation exposure. PMID:26934483

  19. Measuring radiation dose to patients undergoing fluoroscopically-guided interventions

    NASA Astrophysics Data System (ADS)

    Lubis, L. E.; Badawy, M. K.

    2016-03-01

    The increasing prevalence and complexity of fluoroscopically guided interventions (FGI) raises concern regarding radiation dose to patients subjected to the procedure. Despite current evidence showing the risk to patients from the deterministic effects of radiation (e.g. skin burns), radiation induced injuries remain commonplace. This review aims to increase the awareness surrounding radiation dose measurement for patients undergoing FGI. A review of the literature was conducted alongside previous researches from the authors’ department. Studies pertaining to patient dose measurement, its formalism along with current advances and present challenges were reviewed. Current patient monitoring techniques (using available radiation dosimeters), as well as the inadequacy of accepting displayed dose as patient radiation dose is discussed. Furthermore, advances in real-time patient radiation dose estimation during FGI are considered. Patient dosimetry in FGI, particularly in real time, remains an ongoing challenge. The increasing occurrence and sophistication of these procedures calls for further advances in the field of patient radiation dose monitoring. Improved measuring techniques will aid clinicians in better predicting and managing radiation induced injury following FGI, thus improving patient care.

  20. Concurrent image and dose reconstruction for image guided radiation therapy

    NASA Astrophysics Data System (ADS)

    Sheng, Ke

    The importance of knowing the patient actual position is essential for intensity modulated radiation therapy (IMRT). This procedure uses tightened margin and escalated tumor dose. In order to eliminate the uncertainty of the geometry in IMRT, daily imaging is prefered. The imaging dose, limited field of view and the imaging concurrency of the MVCT (mega-voltage computerized tomography) are investigated in this work. By applying partial volume imaging (PVI), imaging dose can be reduced for a region of interest (ROI) imaging. The imaging dose and the image quality are quantitatively balanced with inverse imaging dose planning. With PVI, 72% average imaging dose reduction was observed on a typical prostate patient case. The algebraic reconstruction technique (ART) based projection onto convex sets (POCS) shows higher robustness than filtered back projection when available imaging data is not complete and continuous. However, when the projection is continuous as in the actual delivery, a non-iterative wavelet based multiresolution local tomography (WMLT) is able to achieve 1% accuracy within the ROI. The reduction of imaging dose is dependent on the size of ROI. The improvement of concurrency is also discussed based on the combination of PVI and WMLT. Useful target images were acquired with treatment beams and the temporal resolution can be increased to 20 seconds in tomotherapy. The data truncation problem with the portal imager was also studied. Results show that the image quality is not adversely affected by truncation when WMLT is employed. When the online imaging is available, a perturbation dose calculation (PDC) that estimates the actual delivered dose is proposed. Corrected from the Fano's theorem, PDC counts the first order term in the density variation to calculate the internal and external anatomy change. Although change in the dose distribution that is caused by the internal organ motion is less than 1% for 6 MV beams, the external anatomy change has

  1. A Bayesian Semiparametric Model for Radiation Dose-Response Estimation.

    PubMed

    Furukawa, Kyoji; Misumi, Munechika; Cologne, John B; Cullings, Harry M

    2016-06-01

    In evaluating the risk of exposure to health hazards, characterizing the dose-response relationship and estimating acceptable exposure levels are the primary goals. In analyses of health risks associated with exposure to ionizing radiation, while there is a clear agreement that moderate to high radiation doses cause harmful effects in humans, little has been known about the possible biological effects at low doses, for example, below 0.1 Gy, which is the dose range relevant to most radiation exposures of concern today. A conventional approach to radiation dose-response estimation based on simple parametric forms, such as the linear nonthreshold model, can be misleading in evaluating the risk and, in particular, its uncertainty at low doses. As an alternative approach, we consider a Bayesian semiparametric model that has a connected piece-wise-linear dose-response function with prior distributions having an autoregressive structure among the random slope coefficients defined over closely spaced dose categories. With a simulation study and application to analysis of cancer incidence data among Japanese atomic bomb survivors, we show that this approach can produce smooth and flexible dose-response estimation while reasonably handling the risk uncertainty at low doses and elsewhere. With relatively few assumptions and modeling options to be made by the analyst, the method can be particularly useful in assessing risks associated with low-dose radiation exposures. PMID:26581473

  2. The Radiation Dose-Response of the Human Spinal Cord

    SciTech Connect

    Schultheiss, Timothy E.

    2008-08-01

    Purpose: To characterize the radiation dose-response of the human spinal cord. Methods and Materials: Because no single institution has sufficient data to establish a dose-response function for the human spinal cord, published reports were combined. Requisite data were dose and fractionation, number of patients at risk, number of myelopathy cases, and survival experience of the population. Eight data points for cervical myelopathy were obtained from five reports. Using maximum likelihood estimation correcting for the survival experience of the population, estimates were obtained for the median tolerance dose, slope parameter, and {alpha}/{beta} ratio in a logistic dose-response function. An adequate fit to thoracic data was not possible. Hyperbaric oxygen treatments involving the cervical cord were also analyzed. Results: The estimate of the median tolerance dose (cervical cord) was 69.4 Gy (95% confidence interval, 66.4-72.6). The {alpha}/{beta} = 0.87 Gy. At 45 Gy, the (extrapolated) probability of myelopathy is 0.03%; and at 50 Gy, 0.2%. The dose for a 5% myelopathy rate is 59.3 Gy. Graphical analysis indicates that the sensitivity of the thoracic cord is less than that of the cervical cord. There appears to be a sensitizing effect from hyperbaric oxygen treatment. Conclusions: The estimate of {alpha}/{beta} is smaller than usually quoted, but values this small were found in some studies. Using {alpha}/{beta} = 0.87 Gy, one would expect a considerable advantage by decreasing the dose/fraction to less than 2 Gy. These results were obtained from only single fractions/day and should not be applied uncritically to hyperfractionation.

  3. Comparative investigation of three dose rate meters for their viability in pulsed radiation fields.

    PubMed

    Gotz, M; Karsch, L; Pawelke, J

    2015-06-01

    Pulsed radiation fields, characterized by microsecond pulse duration and correspondingly high pulse dose rates, are increasingly used in therapeutic, diagnostic and research applications. Yet, dose rate meters which are used to monitor radiation protection areas or to inspect radiation shielding are mostly designed, characterized and tested for continuous fields and show severe deficiencies in highly pulsed fields. Despite general awareness of the problem, knowledge of the specific limitations of individual instruments is very limited, complicating reliable measurements. We present here the results of testing three commercial dose rate meters, the RamION ionization chamber, the LB 1236-H proportional counter and the 6150AD-b scintillation counter, for their response in pulsed radiation fields of varied pulse dose and duration. Of these three the RamION proved reliable, operating in a pulsed radiation field within its specifications, while the other two instruments were only able to measure very limited pulse doses and pulse dose rates reliably. PMID:25978117

  4. A technique for multi-dimensional optimization of radiation dose, contrast dose, and image quality in CT imaging

    NASA Astrophysics Data System (ADS)

    Sahbaee, Pooyan; Abadi, Ehsan; Sanders, Jeremiah; Becchetti, Marc; Zhang, Yakun; Agasthya, Greeshma; Segars, Paul; Samei, Ehsan

    2016-03-01

    The purpose of this study was to substantiate the interdependency of image quality, radiation dose, and contrast material dose in CT towards the patient-specific optimization of the imaging protocols. The study deployed two phantom platforms. First, a variable sized phantom containing an iodinated insert was imaged on a representative CT scanner at multiple CTDI values. The contrast and noise were measured from the reconstructed images for each phantom diameter. Linearly related to iodine-concentration, contrast to noise ratio (CNR), was calculated for different iodine-concentration levels. Second, the analysis was extended to a recently developed suit of 58 virtual human models (5D-XCAT) with added contrast dynamics. Emulating a contrast-enhanced abdominal image procedure and targeting a peak-enhancement in aorta, each XCAT phantom was "imaged" using a CT simulation platform. 3D surfaces for each patient/size established the relationship between iodine-concentration, dose, and CNR. The Sensitivity of Ratio (SR), defined as ratio of change in iodine-concentration versus dose to yield a constant change in CNR was calculated and compared at high and low radiation dose for both phantom platforms. The results show that sensitivity of CNR to iodine concentration is larger at high radiation dose (up to 73%). The SR results were highly affected by radiation dose metric; CTDI or organ dose. Furthermore, results showed that the presence of contrast material could have a profound impact on optimization results (up to 45%).

  5. Reduction of Radiation Doses to Patients and Staff During Endoscopic Retrograde Cholangiopancreatography

    PubMed Central

    Sulieman, Abdelmoneim; Paroutoglou, Georgios; Kapsoritakis, Andreas; Kapatenakis, Anargeyros; Potamianos, Spiros; Vlychou, Marianna; Theodorou, Kiki

    2011-01-01

    Background/Aim: Endoscopic retrograde cholangiopancreatography (ERCP) is associated with a considerable radiation exposure for patients and staff. While optimization of the radiation dose is recommended, few studies have been published. The purpose of this study has been to measure patient and staff radiation dose, to estimate the effective dose and radiation risk using digital fluoroscopic images. Entrance skin dose (ESD), organ and effective doses were estimated for patients and staff. Materials and Methods: Fifty-seven patients were studied using digital X-ray machine and thermoluminescent dosimeters (TLD) to measure ESD at different body sites. Organ and surface dose to specific radiosensitive organs was carried out. The mean, median, minimum, third quartile and the maximum values are presented due to the asymmetry in data distribution. Results: The mean ESD, exit and thyroid surface dose were estimated to be 75.6 mGy, 3.22 mGy and 0.80 mGy, respectively. The mean effective dose for both gastroenterologist and assistant is 0.01 mSv. The mean patient effective dose was 4.16 mSv, and the cancer risk per procedure was estimated to be 2 × 10-5 Conclusion: ERCP with fluoroscopic technique demonstrate improved dose reduction, compared to the conventional radiographic based technique, reducing the surface dose by a factor of 2, without compromising the diagnostic findings. The radiation absorbed doses to the different organs and effective doses are relatively low. PMID:21196649

  6. Non linear processes modulated by low doses of radiation exposure

    NASA Astrophysics Data System (ADS)

    Mariotti, Luca; Ottolenghi, Andrea; Alloni, Daniele; Babini, Gabriele; Morini, Jacopo; Baiocco, Giorgio

    The perturbation induced by radiation impinging on biological targets can stimulate the activation of several different pathways, spanning from the DNA damage processing to intra/extra -cellular signalling. In the mechanistic investigation of radiobiological damage this complex “system” response (e.g. omics, signalling networks, micro-environmental modifications, etc.) has to be taken into account, shifting from a focus on the DNA molecule solely to a systemic/collective view. An additional complication comes from the finding that the individual response of each of the involved processes is often not linear as a function of the dose. In this context, a systems biology approach to investigate the effects of low dose irradiations on intra/extra-cellular signalling will be presented, where low doses of radiation act as a mild perturbation of a robustly interconnected network. Results obtained through a multi-level investigation of both DNA damage repair processes (e.g. gamma-H2AX response) and of the activation kinetics for intra/extra cellular signalling pathways (e.g. NFkB activation) show that the overall cell response is dominated by non-linear processes - such as negative feedbacks - leading to possible non equilibrium steady states and to a poor signal-to-noise ratio. Together with experimental data of radiation perturbed pathways, different modelling approaches will be also discussed.

  7. Patient radiation dose audits for fluoroscopically guided interventional procedures

    SciTech Connect

    Balter, Stephen; Rosenstein, Marvin; Miller, Donald L.; Schueler, Beth; Spelic, David

    2011-03-15

    Purpose: Quality management for any use of medical x-ray imaging should include monitoring of radiation dose. Fluoroscopically guided interventional (FGI) procedures are inherently clinically variable and have the potential for inducing deterministic injuries in patients. The use of a conventional diagnostic reference level is not appropriate for FGI procedures. A similar but more detailed quality process for management of radiation dose in FGI procedures is described. Methods: A method that takes into account both the inherent variability of FGI procedures and the risk of deterministic injuries from these procedures is suggested. The substantial radiation dose level (SRDL) is an absolute action level (with regard to patient follow-up) below which skin injury is highly unlikely and above which skin injury is possible. The quality process for FGI procedures collects data from all instances of a given procedure from a number of facilities into an advisory data set (ADS). An individual facility collects a facility data set (FDS) comprised of all instances of the same procedure at that facility. The individual FDS is then compared to the multifacility ADS with regard to the overall shape of the dose distributions and the percent of instances in both the ADS and the FDS that exceed the SRDL. Results: Samples of an ADS and FDS for percutaneous coronary intervention, using the dose metric of reference air kerma (K{sub a,r}) (i.e., the cumulative air kerma at the reference point), are used to illustrate the proposed quality process for FGI procedures. Investigation is warranted whenever the FDS is noticeably different from the ADS for the specific FGI procedure and particularly in two circumstances: (1) When the facility's local median K{sub a,r} exceeds the 75th percentile of the ADS and (2) when the percent of instances where K{sub a,r} exceeds the facility-selected SRDL is greater for the FDS than for the ADS. Conclusions: Analysis of the two data sets (ADS and FDS) and

  8. Estimation of Internal Radiation Dose from both Immediate Releases and Continued Exposures to Contaminated Materials

    SciTech Connect

    Napier, Bruce A.

    2012-03-26

    A brief description is provided of the basic concepts related to 'internal dose' and how it differs from doses that result from radioactive materials and direct radiation outside of the body. The principles of radiation dose reconstruction, as applied to both internal and external doses, is discussed based upon a recent publication prepared by the US National Council on Radiation Protection and Measurements. Finally, ideas are introduced related to residual radioactive contamination in the environment that has resulted from the releases from the damaged reactors and also to the management of wastes that may be generated in both regional cleanup and NPP decommissioning.

  9. Estimation of internal radiation dose from both immediate releases and continued exposures to contaminated materials.

    PubMed

    Napier, Bruce

    2012-03-01

    A brief description is provided of the basic concepts related to 'internal dose' and how it differs from doses that result from radioactive materials and direct radiation outside of the body. The principles of radiation dose reconstruction, as applied to both internal and external doses, are discussed on the basis of a recent publication prepared by the US National Council on Radiation Protection and Measurements. Finally, ideas are introduced related to residual radioactive contamination in the environment that has resulted from the releases from damaged reactors and also to the management of wastes that may be generated in both regional cleanup and decommissioning of the Fukushima nuclear power plant. PMID:22395282

  10. Fewer Doses of HPV Vaccine Result in Immune Response Similar to Three-Dose Regimen

    MedlinePlus

    ... Releases NCI News Note Fewer doses of HPV vaccine result in immune response similar to three-dose ... that two doses of a human papillomavirus (HPV) vaccine, trademarked as Cervarix, resulted in similar serum antibody ...

  11. Total dose performance of radiation hardened voltage regulators and references

    NASA Technical Reports Server (NTRS)

    McClure, S.; Gorelick, J.; Pease, R.; Rax, B.; Ladbury, R.

    2001-01-01

    Total dose test of commercially available radiation hardened bipolar voltage regulators and references show reduced sensitivity to dose rate and varying sensitivity to bias under pressure. Behavior of critical parameters in different dose rate and bias conditions is compared and the impact to hardness assurance methodology is discussed.

  12. Has the use of computers in radiation therapy improved the accuracy in radiation dose delivery?

    NASA Astrophysics Data System (ADS)

    Van Dyk, J.; Battista, J.

    2014-03-01

    Purpose: It is well recognized that computer technology has had a major impact on the practice of radiation oncology. This paper addresses the question as to how these computer advances have specifically impacted the accuracy of radiation dose delivery to the patient. Methods: A review was undertaken of all the key steps in the radiation treatment process ranging from machine calibration to patient treatment verification and irradiation. Using a semi-quantitative scale, each stage in the process was analysed from the point of view of gains in treatment accuracy. Results: Our critical review indicated that computerization related to digital medical imaging (ranging from target volume localization, to treatment planning, to image-guided treatment) has had the most significant impact on the accuracy of radiation treatment. Conversely, the premature adoption of intensity-modulated radiation therapy has actually degraded the accuracy of dose delivery compared to 3-D conformal radiation therapy. While computational power has improved dose calibration accuracy through Monte Carlo simulations of dosimeter response parameters, the overall impact in terms of percent improvement is relatively small compared to the improvements accrued from 3-D/4-D imaging. Conclusions: As a result of computer applications, we are better able to see and track the internal anatomy of the patient before, during and after treatment. This has yielded the most significant enhancement to the knowledge of "in vivo" dose distributions in the patient. Furthermore, a much richer set of 3-D/4-D co-registered dose-image data is thus becoming available for retrospective analysis of radiobiological and clinical responses.

  13. Evaluation of the Stochastic Effects of Low-Dose Radiation: Dose Reconstruction for the Techa River Cohort in Russia

    SciTech Connect

    Degteva, M O.; Kozheurov, V P.; Tolstykh, E I.; Vorobiova, M I.; Anspaugh, L R.; Napier, Bruce A. )

    2001-06-01

    Persons traveling in space can accumulate fairly large doses of radiation, up to several Sv, at low-to-moderate dose rates. In general these dose rates are low enough so that deterministic effects can be avoided, although shielding may be necessary. An important question, however, is the stochastic effects (induction of cancer and genetic defects) of these doses. Most radiation-risk estimates are based on dose reconstruction and epidemiologic follow-up of the survivors of the atomic bombings on Japan, events that delivered doses nearly instantaneously. It has been hoped that stochastic effects would be less probable for radiation delivered at lower dose rates, but few opportunities have been available to examine this question in humans. The Mayak Production Association (MPA) was the first Russian site for the production and separation of plutonium. This plant began operation in 1948, and during its early days there were high occupational doses as well as technological failures that resulted in the release of large amounts of waste (about 10^17 Bq of liquid wastes) into the rather small Techa River. Residents along the Techa River were exposed to external radiation, and they ingested foods contaminated with 90Sr and other radionuclides. The?Techa River Cohort? has been studied for several years by scientists from the Urals Research Center for Radiation Medicine (URCRM). The purpose of the project considered here is to improve the dose-reconstruction system for the Techa River Cohort that has been under development for many years by Russian scientists at the URCRM. This, and the companion epidemiologic studies, are deemed to be unique and important, as members of the Techa River Cohort received red bone marrow doses of up to 3 Gy, but at low-to-moderate-dose rates. An increase in leukemia and cancer mortality has already been noted for this population, and further study should allow the evaluation of dose-rate-reduction factors for this situation.

  14. Cone beam computed tomography radiation dose and image quality assessments.

    PubMed

    Lofthag-Hansen, Sara

    2010-01-01

    Diagnostic radiology has undergone profound changes in the last 30 years. New technologies are available to the dental field, cone beam computed tomography (CBCT) as one of the most important. CBCT is a catch-all term for a technology comprising a variety of machines differing in many respects: patient positioning, volume size (FOV), radiation quality, image capturing and reconstruction, image resolution and radiation dose. When new technology is introduced one must make sure that diagnostic accuracy is better or at least as good as the one it can be expected to replace. The CBCT brand tested was two versions of Accuitomo (Morita, Japan): 3D Accuitomo with an image intensifier as detector, FOV 3 cm x 4 cm and 3D Accuitomo FPD with a flat panel detector, FOVs 4 cm x 4 cm and 6 cm x 6 cm. The 3D Accuitomo was compared with intra-oral radiography for endodontic diagnosis in 35 patients with 46 teeth analyzed, of which 41 were endodontically treated. Three observers assessed the images by consensus. The result showed that CBCT imaging was superior with a higher number of teeth diagnosed with periapical lesions (42 vs 32 teeth). When evaluating 3D Accuitomo examinations in the posterior mandible in 30 patients, visibility of marginal bone crest and mandibular canal, important anatomic structures for implant planning, was high with good observer agreement among seven observers. Radiographic techniques have to be evaluated concerning radiation dose, which requires well-defined and easy-to-use methods. Two methods: CT dose index (CTDI), prevailing method for CT units, and dose-area product (DAP) were evaluated for calculating effective dose (E) for both units. An asymmetric dose distribution was revealed when a clinical situation was simulated. Hence, the CTDI method was not applicable for these units with small FOVs. Based on DAP values from 90 patient examinations effective dose was estimated for three diagnostic tasks: implant planning in posterior mandible and

  15. COSMIC: A Regimen of Intensity Modulated Radiation Therapy Plus Dose-Escalated, Raster-Scanned Carbon Ion Boost for Malignant Salivary Gland Tumors: Results of the Prospective Phase 2 Trial

    SciTech Connect

    Jensen, Alexandra D.; Nikoghosyan, Anna V.; Lossner, Karen; Haberer, Thomas; Jäkel, Oliver; Münter, Marc W.; Debus, Jürgen

    2015-09-01

    Purpose: To investigate the effect of intensity modulated radiation therapy (IMRT) and dose-escalated carbon ion (C12) therapy in adenoid cystic carcinoma (ACC) and other malignant salivary gland tumors (MSGTs) of the head and neck. Patients and Methods: COSMIC (combined treatment of malignant salivary gland tumors with intensity modulated radiation therapy and carbon ions) is a prospective phase 2 trial of 24 Gy(RBE) C12 followed by 50 Gy IMRT in patients with pathologically confirmed MSGT. The primary endpoint is mucositis Common Terminology Criteria grade 3; the secondary endpoints are locoregional control (LC), progression-free survival (PFS), overall survival (OS), and toxicity. Toxicity was scored according to the Common Terminology Criteria for Adverse Events version 3; treatment response was scored according to Response Evaluation Criteria in Solid Tumors 1.1. Results: Between July 2010 and August 2011, 54 patients were accrued, and 53 were available for evaluation. The median follow-up time was 42 months; patients with microscopically incomplete resections (R1, n=20), gross residual disease (R2, n=17), and inoperable disease (n=16) were included. Eighty-nine percent of patients had ACC, and 57% had T4 tumors. The most common primary sites were paranasal sinus (34%), submandibular gland, and palate. At the completion of radiation therapy, 26% of patients experienced grade 3 mucositis, and 20 patients reported adverse events of the ear (38%). The most common observed late effects were grade 1 xerostomia (49%), hearing impairment (25%, 2% ipsilateral hearing loss), and adverse events of the eye (20%), but no visual impairment or loss of vision. Grade 1 central nervous system necrosis occurred in 6%, and 1 grade 4 ICA hemorrhage without neurologic sequelae. The best response was 54% (complete response/partial remission). At 3 years, the LC, PFS, and OS were 81.9%, 57.9%, and 78.4%, respectively. No difference was found regarding resection status. The

  16. SCCT guidelines on radiation dose and dose-optimization strategies in cardiovascular CT

    PubMed Central

    Halliburton, Sandra S.; Abbara, Suhny; Chen, Marcus Y.; Gentry, Ralph; Mahesh, Mahadevappa; Raff, Gilbert L.; Shaw, Leslee J.; Hausleiter, Jörg

    2012-01-01

    Over the last few years, computed tomography (CT) has developed into a standard clinical test for a variety of cardiovascular conditions. The emergence of cardiovascular CT during a period of dramatic increase in radiation exposure to the population from medical procedures and heightened concern about the subsequent potential cancer risk has led to intense scrutiny of the radiation burden of this new technique. This has hastened the development and implementation of dose reduction tools and prompted closer monitoring of patient dose. In an effort to aid the cardiovascular CT community in incorporating patient-centered radiation dose optimization and monitoring strategies into standard practice, the Society of Cardiovascular Computed Tomography has produced a guideline document to review available data and provide recommendations regarding interpretation of radiation dose indices and predictors of risk, appropriate use of scanner acquisition modes and settings, development of algorithms for dose optimization, and establishment of procedures for dose monitoring. PMID:21723512

  17. Radiation dose and shielding for the space station

    NASA Technical Reports Server (NTRS)

    Mccormack, Percival D.

    1988-01-01

    Significant differences in dose prediction for Space Station arise depending on whether or not the magnetic field model is extrapolated into the future. The basis for these calculations is examined in detail, and the importance of the residual atmospheric layer at altitudes below 1000 km, with respect to radiation attenuation, is emphasized. Dosimetry results from Shuttle flights are presented and compared with the computed results. It is recommended that, at this stage, no extrapolation of the magnetic field into the future be included in the calculations. A model adjustment, to replace this arbitrary procedure, is presented. Dose predictions indicate that, at altitudes below 500 km and at low inclination, and with nominal module wall thickness (0.125 in. aluminum), orbit stay times of 90 days in Space Station would result in quarterly radiation doses to the crew, which are well within present limits for both males and females. Countermeasures would be required for stay times of a year or more and the measure of increasing shielding is examined.

  18. The Measurement of Radiation Dose in SJ-10 satellite

    NASA Astrophysics Data System (ADS)

    Shenyi, Zhang

    SJ-10 scientific satellite will be launched after a few years in china. The SJ-10 satellite is a recoverable satellite researching for materials and life science. Orbit altitude of 600 km circular orbit with an inclination of 63 " Space Radiation Biology Researching " is a sub-project in SJ-10 satellite, which will research the relation between the biological effect and space particle's radiation. The project include the biological materials for biological effect researching and "The Detector of Space Radiation Biology " for measurement the dose in the space. In SJ-10 satellite's orbit, The source of the particle radiation is from earth radiation-belt and galaxy cosmic ray . The propose of "The Detector of space radiation biology " is monitor the particle radiation, service to the scientific analysis. The instrument include the semiconductor particle radiation monitoring package and Tissue-equivalent particle radiation monitoring package. The semiconductor particle radiation monitoring package is used to detect the flux of the protons, electrons and heavy ions, also the linear energy transfer(LET) in the silicon material. The element composition of Tissue-equivalent particle radiation monitoring package is similar to the biology issue. It can measure the space particles in biological materials, the value of the LET, dose, dose equivalent, and more Keywords: SJ-10 satellites; radiation biological effects; semiconductor particle radiation moni-toring package; Tissue-equivalent particle radiation monitoring package

  19. Patient radiation doses for electron beam CT

    SciTech Connect

    Castellano, Isabel A.; Dance, David R.; Skinner, Claire L.; Evans, Phil M.

    2005-08-15

    A Monte Carlo based computer model has been developed for electron beam computed tomography (EBCT) to calculate organ and effective doses in a humanoid hermaphrodite phantom. The program has been validated by comparison with experimental measurements of the CT dose index in standard head and body CT dose phantoms; agreement to better than 8% has been found. The robustness of the model has been established by varying the input parameters. The amount of energy deposited at the 12:00 position of the standard body CT dose phantom is most susceptible to rotation angle, whereas that in the central region is strongly influenced by the beam quality. The program has been used to investigate the changes in organ absorbed doses arising from partial and full rotation about supine and prone subjects. Superficial organs experience the largest changes in absorbed dose with a change in subject orientation and for partial rotation. Effective doses for typical clinical scan protocols have been calculated and compared with values obtained using existing dosimetry techniques based on full rotation. Calculations which make use of Monte Carlo conversion factors for the scanner that best matches the EBCT dosimetric characteristics consistently overestimate the effective dose in supine subjects by typically 20%, and underestimate the effective dose in prone subjects by typically 13%. These factors can therefore be used to correct values obtained in this way. Empirical dosimetric techniques based on the dose-length product yield errors as great as 77%. This is due to the sensitivity of the dose length product to individual scan lengths. The magnitude of these errors is reduced if empirical dosimetric techniques based on the average absorbed dose in the irradiated volume (CTDI{sub vol}) are used. Therefore conversion factors specific to EBCT have been calculated to convert the CTDI{sub vol} to an effective dose.

  20. Alternative Physical Quality Parameters Influences Effectiveness of Lower Doses Ionizing Radiation

    NASA Astrophysics Data System (ADS)

    Yousif, Abubaker Ali; Bahari, Ismail Bin; Yasir, Muhamad Samudi

    2011-03-01

    It has been proved in many studied that the absorbed dose is not good physical quality parameter to quantify the radiation effects at lower doses. However relative biological effect (RBE) is still used as a major parameter of radiation effectiveness. Whereas linear energy transfer (LET) is inadequate physical parameter, therefore the weaknesses in using RBE-LET system for radiation protection have been investigated. Secondary data of V79 has reanalyzed to help complement the inadequacy current method in assessing cell inactivation at lower doses. Results of analysis show that the effectiveness of densely ionizing radiation is better quantified using mean free path (λ).

  1. Daily Sodium Butyrate Enema for the Prevention of Radiation Proctitis in Prostate Cancer Patients Undergoing Radical Radiation Therapy: Results of a Multicenter Randomized Placebo-Controlled Dose-Finding Phase 2 Study

    SciTech Connect

    Maggio, Angelo; Magli, Alessandro; Rancati, Tiziana; Fiorino, Claudio; Valvo, Francesca; Fellin, Giovanni; Ricardi, Umberto; Munoz, Fernando; Cosentino, Dorian; Cazzaniga, Luigi Franco; Valdagni, Riccardo; Vavassori, Vittorio

    2014-07-01

    Purpose: To evaluate the efficacy of sodium butyrate enemas (NABUREN) in prostate cancer radiation therapy (RT) in reducing the incidence, severity, and duration of acute RT-induced proctitis. Methods and Materials: 166 patients, randomly allocated to 1 of 4 groups (rectal sodium butyrate 1 g, 2 g, or 4 g daily or placebo), were treated with NABUREN during and 2 weeks after RT. The grade of proctitis was registered in a daily diary. The correlation between NABUREN and proctitis was investigated through χ{sup 2} statistics. The toxicity endpoints considered were as follows: total number of days with grade ≥1 proctitis (≥G1); total number of days with grade ≥2 proctitis (≥G2); ≥G1 and ≥G2 proctitis lasting at least 3 and 5 consecutive days starting from week 4 (≥G1+3d, ≥G2+3d); damaging effects of RT on rectal mucosa as measured by endoscopy. The relationship between endpoints and pretreatment morbidities, hormonal therapy, presence of diabetes or hypertension, abdominal surgery, or hemorrhoids was investigated by univariate analysis. Results: The patients were randomly allocated to the 4 arms. No difference in the distribution of comorbidities among the arms was observed (P>.09). The mean ≥G1 and ≥G2 proctitis were 7.8 and 4.9 for placebo and 8.9 and 4.7 for the NABUREN group, respectively. No favorable trend in reduction of incidence, severity, and duration of ≥G1 and ≥G2 proctitis was observed with NABUREN use. In univariate analysis, ≥G1+3d toxicity was found to be related to hemorrhoids (P=.008), and a slight correlation was found between ≥G2 proctitis and hormonal therapy (P=.06). The RT effects on rectal mucosa as based on endoscopic assessment were mainly related to diabetes (P<.01). Endoscopy data at 6 week showed no significant difference between the placebo and butyrate arms. The other investigated endpoints were not correlated with any of the clinical risk factors analyzed. Conclusion: There was no evidence of efficacy

  2. Space radiation protection: comparison of effective dose to bone marrow dose equivalent.

    PubMed

    Hoff, Jennifer L; Townsend, Lawrence W; Zapp, E Neal

    2002-12-01

    In many instances, bone marrow dose equivalents averaged over the entire body have been used as a surrogate for whole-body dose equivalents in space radiation protection studies. However, career radiation limits for space missions are expressed as effective doses. This study compares calculations of effective doses to average bone marrow dose equivalents for several large solar particle events (SPEs) and annual galactic cosmic ray (GCR) spectra, in order to examine the suitability of substituting bone marrow dose equivalents for effective doses. Organ dose equivalents are computed for all radiosensitive organs listed in NCRP Report 116 using the BRYNTRN and HZETRN space radiation transport codes and the Computerized Anatomical Man (CAM) model. These organ dose equivalents are then weighted with the appropriate tissue weighting factors to obtain effective doses. Various thicknesses of aluminum shielding, which are representative of nominal spacecraft and SPE storm shelter configurations, are used in the analyses. For all SPE configurations, the average bone marrow dose equivalent is considerably less than the calculated effective dose. For comparisons of the GCR, there is less than a ten percent difference between the two methods. In all cases, the gonads made up the largest percentage of the effective dose. PMID:12793744

  3. Effect of radiation energy and intracellular iron dose on iron oxide nanoparticle enhancement of radiation cytotoxicity

    NASA Astrophysics Data System (ADS)

    Mazur, Courtney M.; Strawbridge, Rendall R.; Thompson, Ella S.; Petryk, Alicia A.; Gladstone, David J.; Hoopes, P. Jack

    2015-03-01

    Iron oxide nanoparticles (IONPs) are one of several high-Z materials currently being investigated for their ability to enhance the cytotoxic effects of therapeutic ionizing radiation. Studies with iron oxide, silver, gold, and hafnium oxide suggest radiation dose, radiation energy, cell type, and the type and level of metallic nanoparticle are all critical factors in achieving radiation enhancement in tumor cells. Using a single 4 Gy radiation dose, we compared the level of tumor cell cytotoxicity at two different intracellular iron concentrations and two different radiation energies in vitro. IONPs were added to cell culture media at concentrations of 0.25 mg Fe/mL and 1.0 mg Fe/mL and incubated with murine breast adenocarcinoma (MTG-B) cells for 72 hours. Extracellular iron was then removed and cells were irradiated at either 662 keV or 10 MV. At the 0.25 mg Fe/mL dose (4 pg Fe/cell), radiation energy did not affect the level of cytotoxicity. However with 1.0 mg Fe/mL (9 pg Fe/cell), the higher 10 MV radiation energy resulted in 50% greater cytotoxicity as compared to cells without IONPs irradiated at this energy. These results suggest IONPs may be able to significantly enhance the cytotoxic effects of radiation and improve therapeutic ratio if they can be selectively associated with cancer cells and/or tumors. Ongoing in vivo studies of IONP radiation enhancement in a murine tumor model are too immature to draw conclusions from at this time, however preliminary data suggests similar effectiveness of IONP radiation enhancement at 6 MV and 18 MV energy levels. In addition to the IONP-based radiation enhancement demonstrated here, the use of tumor-localized IONP with an externally delivered, non-toxic alternating magnetic field affords the opportunity to selectively heat and kill tumor cells. Combining IONP-based radiation sensitization and heat-based cytotoxicity provides a unique and potentially highly effective opportunity for therapeutic ratio enhancement.

  4. Small Bowel Dose Tolerance for Stereotactic Body Radiation Therapy.

    PubMed

    LaCouture, Tamara A; Xue, Jinyu; Subedi, Gopal; Xu, Qianyi; Lee, Justin T; Kubicek, Gregory; Asbell, Sucha O

    2016-04-01

    Inconsistencies permeate the literature regarding small bowel dose tolerance limits for stereotactic body radiation therapy (SBRT) treatments. In this review, we organized these diverse published limits with MD Anderson at Cooper data into a unified framework, constructing the dose-volume histogram (DVH) Risk Map, demonstrating low-risk and high-risk SBRT dose tolerance limits for small bowel. Statistical models of clinical data from 2 institutions were used to assess the safety spectrum of doses used in the exposure of the gastrointestinal tract in SBRT; 30% of the analyzed cases had vascular endothelial growth factor inhibitors (VEGFI) or other biological agents within 2 years before or after SBRT. For every dose tolerance limit in the DVH Risk Map, the probit dose-response model was used to estimate the risk level from our clinical data. Using the current literature, 21Gy to 5cc of small bowel in 3 fractions has low toxicity and is reasonably safe, with 6.5% estimated risk of grade 3 or higher complications, per Common Terminology Criteria for Adverse Events version 4.0. In the same fractionation for the same volume, if lower risk is required, 16.2Gy has an estimated risk of only 2.5%. Other volumes and fractionations are also reviewed; for all analyzed high-risk small bowel limits, the risk is 8.2% or less, and the low-risk limits have 4% or lower estimated risk. The results support current clinical practice, with some possibility for dose escalation. PMID:27000513

  5. Total-dose radiation effects data for semiconductor devices, volume 2

    NASA Technical Reports Server (NTRS)

    Price, W. E.; Martin, K. E.; Nichols, D. K.; Gauthier, M. K.; Brown, S. F.

    1981-01-01

    Total ionizing dose radiation test data on integrated circuits are analyzed. Tests were performed with the electron accelerator (Dynamitron) that provides a steady state 2.5 MeV electron beam. Some radiation exposures were made with a Cobalt-60 gamma ray source. The results obtained with the Cobalt-60 source are considered an approximate measure of the radiation damage that would be incurred by an equivalent dose of electrons.

  6. Ultraviolet Radiation Dose National Standard of México

    NASA Astrophysics Data System (ADS)

    Cardoso, R.; Rosas, E.

    2006-09-01

    We present the Ultraviolet (UV) Radiation Dose National Standard for México. The establishment of this measurement reference at Centro Nacional de Metrología (CENAM) eliminates the need of contacting foreign suppliers in the search for traceability towards the SI units when calibrating instruments at 365 nm. Further more, the UV Radiation Dose National Standard constitutes a highly accurate and reliable source for the UV radiation dose measurements performed in medical and cosmetic treatments as in the the food and pharmaceutics disinfection processes, among other.

  7. Effective Dose from Stray Radiation for a Patient Receiving Proton Therapy for Liver Cancer

    NASA Astrophysics Data System (ADS)

    Taddei, Phillip J.; Krishnan, Sunil; Mirkovic, Dragan; Yepes, Pablo; Newhauser, Wayne D.

    2009-03-01

    Because of its advantageous depth-dose relationship, proton radiotherapy is an emerging treatment modality for patients with liver cancer. Although the proton dose distribution conforms to the target, healthy tissues throughout the body receive low doses of stray radiation, particularly neutrons that originate in the treatment unit or in the patient. The aim of this study was to calculate the effective dose from stray radiation and estimate the corresponding risk of second cancer fatality for a patient receiving proton beam therapy for liver cancer. Effective dose from stray radiation was calculated using detailed Monte Carlo simulations of a double-scattering proton therapy treatment unit and a voxelized human phantom. The treatment plan and phantom were based on CT images of an actual adult patient diagnosed with primary hepatocellular carcinoma. For a prescribed dose of 60 Gy to the clinical target volume, the effective dose from stray radiation was 370 mSv; 61% of this dose was from neutrons originating outside of the patient while the remaining 39% was from neutrons originating within the patient. The excess lifetime risk of fatal second cancer corresponding to the total effective dose from stray radiation was 1.2%. The results of this study establish a baseline estimate of the stray radiation dose and corresponding risk for an adult patient undergoing proton radiotherapy for liver cancer and provide new evidence to corroborate the suitability of proton beam therapy for the treatment of liver tumors.

  8. Effective Dose from Stray Radiation for a Patient Receiving Proton Therapy for Liver Cancer

    SciTech Connect

    Taddei, Phillip J.; Krishnan, Sunil; Mirkovic, Dragan; Newhauser, Wayne D.; Yepes, Pablo

    2009-03-10

    Because of its advantageous depth-dose relationship, proton radiotherapy is an emerging treatment modality for patients with liver cancer. Although the proton dose distribution conforms to the target, healthy tissues throughout the body receive low doses of stray radiation, particularly neutrons that originate in the treatment unit or in the patient. The aim of this study was to calculate the effective dose from stray radiation and estimate the corresponding risk of second cancer fatality for a patient receiving proton beam therapy for liver cancer. Effective dose from stray radiation was calculated using detailed Monte Carlo simulations of a double-scattering proton therapy treatment unit and a voxelized human phantom. The treatment plan and phantom were based on CT images of an actual adult patient diagnosed with primary hepatocellular carcinoma. For a prescribed dose of 60 Gy to the clinical target volume, the effective dose from stray radiation was 370 mSv; 61% of this dose was from neutrons originating outside of the patient while the remaining 39% was from neutrons originating within the patient. The excess lifetime risk of fatal second cancer corresponding to the total effective dose from stray radiation was 1.2%. The results of this study establish a baseline estimate of the stray radiation dose and corresponding risk for an adult patient undergoing proton radiotherapy for liver cancer and provide new evidence to corroborate the suitability of proton beam therapy for the treatment of liver tumors.

  9. Second Solid Cancers After Radiation Therapy: A Systematic Review of the Epidemiologic Studies of the Radiation Dose-Response Relationship

    SciTech Connect

    Berrington de Gonzalez, Amy; Gilbert, Ethel; Curtis, Rochelle; Inskip, Peter; Kleinerman, Ruth; Morton, Lindsay; Rajaraman, Preetha; Little, Mark P.

    2013-06-01

    Rapid innovations in radiation therapy techniques have resulted in an urgent need for risk projection models for second cancer risks from high-dose radiation exposure, because direct observation of the late effects of newer treatments will require patient follow-up for a decade or more. However, the patterns of cancer risk after fractionated high-dose radiation are much less well understood than those after lower-dose exposures (0.1-5 Gy). In particular, there is uncertainty about the shape of the dose-response curve at high doses and about the magnitude of the second cancer risk per unit dose. We reviewed the available evidence from epidemiologic studies of second solid cancers in organs that received high-dose exposure (>5 Gy) from radiation therapy where dose-response curves were estimated from individual organ-specific doses. We included 28 eligible studies with 3434 second cancer patients across 11 second solid cancers. Overall, there was little evidence that the dose-response curve was nonlinear in the direction of a downturn in risk, even at organ doses of ≥60 Gy. Thyroid cancer was the only exception, with evidence of a downturn after 20 Gy. Generally the excess relative risk per Gray, taking account of age and sex, was 5 to 10 times lower than the risk from acute exposures of <2 Gy among the Japanese atomic bomb survivors. However, the magnitude of the reduction in risk varied according to the second cancer. The results of our review provide insights into radiation carcinogenesis from fractionated high-dose exposures and are generally consistent with current theoretical models. The results can be used to refine the development of second solid cancer risk projection models for novel radiation therapy techniques.

  10. CT radiation dose optimization and estimation: an update for radiologists.

    PubMed

    Goo, Hyun Woo

    2012-01-01

    In keeping with the increasing utilization of CT examinations, the greater concern about radiation hazards from examinations has been addressed. In this regard, CT radiation dose optimization has been given a great deal of attention by radiologists, referring physicians, technologists, and physicists. Dose-saving strategies are continuously evolving in terms of imaging techniques as well as dose management. Consequently, regular updates of this issue are necessary especially for radiologists who play a pivotal role in this activity. This review article will provide an update on how we can optimize CT dose in order to maximize the benefit-to-risk ratio of this clinically useful diagnostic imaging method. PMID:22247630

  11. Radiation dose reduction in computed tomography: techniques and future perspective

    PubMed Central

    Yu, Lifeng; Liu, Xin; Leng, Shuai; Kofler, James M; Ramirez-Giraldo, Juan C; Qu, Mingliang; Christner, Jodie; Fletcher, Joel G; McCollough, Cynthia H

    2011-01-01

    Despite universal consensus that computed tomography (CT) overwhelmingly benefits patients when used for appropriate indications, concerns have been raised regarding the potential risk of cancer induction from CT due to the exponentially increased use of CT in medicine. Keeping radiation dose as low as reasonably achievable, consistent with the diagnostic task, remains the most important strategy for decreasing this potential risk. This article summarizes the general technical strategies that are commonly used for radiation dose management in CT. Dose-management strategies for pediatric CT, cardiac CT, dual-energy CT, CT perfusion and interventional CT are specifically discussed, and future perspectives on CT dose reduction are presented. PMID:22308169

  12. Space Radiation Quality Factors and the Delta Ray Dose and Dose-Rate Reduction Effectiveness Factor.

    PubMed

    Cucinotta, Francis A; Cacao, Eliedonna; Alp, Murat

    2016-03-01

    In this paper, the authors recommend that the dose and dose-rate effectiveness factor used for space radiation risk assessments should be based on a comparison of the biological effects of energetic electrons produced along a cosmic ray particles path in low fluence exposures to high dose-rate gamma-ray exposures of doses of about 1 Gy. Methods to implement this approach are described. PMID:26808878

  13. The susceptibility of TaOx-based memristors to high dose rate ionizing radiation and total ionizing dose

    DOE PAGESBeta

    McLain, Michael Lee; Sheridan, Timothy J.; Hjalmarson, Harold Paul; Mickel, Patrick R.; Hanson, Donald J.; McDonald, Joseph K.; Hughart, David Russell; Marinella, Matthew J.

    2014-11-11

    This paper investigates the effects of high dose rate ionizing radiation and total ionizing dose (TID) on tantalum oxide (TaOx) memristors. Transient data were obtained during the pulsed exposures for dose rates ranging from approximately 5.0 ×107 rad(Si)/s to 4.7 ×108 rad(Si)/s and for pulse widths ranging from 50 ns to 50 μs. The cumulative dose in these tests did not appear to impact the observed dose rate response. Static dose rate upset tests were also performed at a dose rate of ~3.0 ×108 rad(Si)/s. This is the first dose rate study on any type of memristive memory technology. Inmore » addition to assessing the tolerance of TaOx memristors to high dose rate ionizing radiation, we also evaluated their susceptibility to TID. The data indicate that it is possible for the devices to switch from a high resistance off-state to a low resistance on-state in both dose rate and TID environments. The observed radiation-induced switching is dependent on the irradiation conditions and bias configuration. Furthermore, the dose rate or ionizing dose level at which a device switches resistance states varies from device to device; the enhanced susceptibility observed in some devices is still under investigation. As a result, numerical simulations are used to qualitatively capture the observed transient radiation response and provide insight into the physics of the induced current/voltages.« less

  14. MOSFET assessment of radiation dose delivered to mice using the Small Animal Radiation Research Platform (SARRP).

    PubMed

    Ngwa, Wilfred; Korideck, Houari; Chin, Lee M; Makrigiorgos, G Mike; Berbeco, Ross I

    2011-12-01

    The Small Animal Radiation Research Platform (SARRP) is a novel isocentric irradiation system that enables state-of-the-art image-guided radiotherapy research to be performed with animal models. This paper reports the results obtained from investigations assessing the radiation dose delivered by the SARRP to different anatomical target volumes in mice. Surgically implanted metal oxide semiconductor field effect transistors (MOSFET) dosimeters were employed for the dose assessment. The results reveal differences between the calculated and measured dose of -3.5 to 0.5%, -5.2 to -0.7%, -3.9 to 0.5%, -5.9 to 2.5%, -5.5 to 0.5%, and -4.3 to 0% for the left kidney, liver, pancreas, prostate, left lung, and brain, respectively. Overall, the findings show less than 6% difference between the delivered and calculated dose, without tissue heterogeneity corrections. These results provide a useful assessment of the need for tissue heterogeneity corrections in SARRP dose calculations for clinically relevant tumor model sites. PMID:21962005

  15. Radiation doses in chest, abdomen and pelvis CT procedures.

    PubMed

    Manssor, E; Abuderman, A; Osman, S; Alenezi, S B; Almehemeid, S; Babikir, E; Alkhorayef, M; Sulieman, A

    2015-07-01

    Computed tomography (CT) scanning is recognised as a high-radiation dose modality and estimated to be 17 % of the radiological procedure and responsible for 70 % of medical radiation exposure. Although diagnostic X rays provide great benefits, their use involves some risk for developing cancer. The objectives of this study are to estimate radiation doses during chest, abdomen and pelvis CT. A total of 51 patients were examined for the evaluation of metastasis of a diagnosed primary tumour during 4 months. A calibrated CT machine from Siemens 64 slice was used. The mean age was 48.0 ± 18.6 y. The mean patient weight was 73.8 ± 16.1 kg. The mean dose-length product was 1493.8 ± 392.1 mGy cm, Volume CT dose index (CTDI vol) was 22.94 ± 5.64 mGy and the mean effective dose was 22.4 ± 5.9 mSv per procedure. The radiation dose per procedure was higher as compared with previous studies. Therefore, the optimisation of patient's radiation doses is required in order to reduce the radiation risk. PMID:25852181

  16. The Concentration Of Tritium In Urine And Internal Radiation Dose Estimation Of PTNBR Radiation Workers

    SciTech Connect

    Tjahaja, Poppy Intan; Sukmabuana, Putu; Aisyah, Neneng Nur

    2010-12-23

    The operation of Triga 2000 reactor in Nuclear Technology Center for Materials and Radiometry (PTNBR BATAN) normally produce tritium radionuclide which is the activation product of deuterium atom in reactor primary cooling water. According to previous monitoring, tritium was detected with the concentration of 8.236{+-}0.677 kBq/L and 1.704{+-}0.046 Bq/L in the primary cooling water and in reactor hall air, respectively. The tritium in reactor hall air chronically can be inhaled by the workers. In this research, tritium content in radiation workers' urine was determined to estimate the internal radiation doses received by the workers. About 50-100 mL of urine samples were collected from 48 PTNBR workers that is classified as 24 radiation workers and 24 administration staffs as a control. Urine samples of 25 mL were then prepared by active charcoal and KMnO{sub 4} addition and followed with complete distillation. The 2 mL of distillate was added with 13 mL scintillator, shaked vigorously and remained in cool and dark condition for about 24 hours. The tritium in the samples was then measured using liquid scintillation counter (LSC) for 1 hour. From the measurement results it was obtained that the tritium concentration in the urine of radiation workers were in the range of not detected and 5.191 Bq/mL, whereas in the administration staffs the concentration were between not detected and 4.607 Bq/mL. Internally radiation doses were calculated using the tritium concentration data, and it was found the averages about 0.602 {mu}Sv/year and 0.532 {mu}Sv/year for radiation workers and administration staffs, respectively. The doses received by the workers were lower than that of the permissible doses from tritium, i.e. 40 {mu}Sv/year.

  17. The Concentration Of Tritium In Urine And Internal Radiation Dose Estimation Of PTNBR Radiation Workers

    NASA Astrophysics Data System (ADS)

    Tjahaja, Poppy Intan; Sukmabuana, Putu; Aisyah, Neneng Nur

    2010-12-01

    The operation of Triga 2000 reactor in Nuclear Technology Center for Materials and Radiometry (PTNBR BATAN) normally produce tritium radionuclide which is the activation product of deuterium atom in reactor primary cooling water. According to previous monitoring, tritium was detected with the concentration of 8.236±0.677 kBq/L and 1.704±0.046 Bq/L in the primary cooling water and in reactor hall air, respectively. The tritium in reactor hall air chronically can be inhaled by the workers. In this research, tritium content in radiation workers' urine was determined to estimate the internal radiation doses received by the workers. About 50-100 mL of urine samples were collected from 48 PTNBR workers that is classified as 24 radiation workers and 24 administration staffs as a control. Urine samples of 25 mL were then prepared by active charcoal and KMnO4 addition and followed with complete distillation. The 2 mL of distillate was added with 13 mL scintillator, shaked vigorously and remained in cool and dark condition for about 24 hours. The tritium in the samples was then measured using liquid scintillation counter (LSC) for 1 hour. From the measurement results it was obtained that the tritium concentration in the urine of radiation workers were in the range of not detected and 5.191 Bq/mL, whereas in the administration staffs the concentration were between not detected and 4.607 Bq/mL. Internally radiation doses were calculated using the tritium concentration data, and it was found the averages about 0.602 μSv/year and 0.532 μSv/year for radiation workers and administration staffs, respectively. The doses received by the workers were lower than that of the permissible doses from tritium, i.e. 40 μSv/year.

  18. Effects of Chronic Low-Dose Radiation on Human Neural Progenitor Cells

    NASA Astrophysics Data System (ADS)

    Katsura, Mari; Cyou-Nakamine, Hiromasa; Zen, Qin; Zen, Yang; Nansai, Hiroko; Amagasa, Shota; Kanki, Yasuharu; Inoue, Tsuyoshi; Kaneki, Kiyomi; Taguchi, Akashi; Kobayashi, Mika; Kaji, Toshiyuki; Kodama, Tatsuhiko; Miyagawa, Kiyoshi; Wada, Youichiro; Akimitsu, Nobuyoshi; Sone, Hideko

    2016-01-01

    The effects of chronic low-dose radiation on human health have not been well established. Recent studies have revealed that neural progenitor cells are present not only in the fetal brain but also in the adult brain. Since immature cells are generally more radiosensitive, here we investigated the effects of chronic low-dose radiation on cultured human neural progenitor cells (hNPCs) derived from embryonic stem cells. Radiation at low doses of 31, 124 and 496 mGy per 72 h was administered to hNPCs. The effects were estimated by gene expression profiling with microarray analysis as well as morphological analysis. Gene expression was dose-dependently changed by radiation. By thirty-one mGy of radiation, inflammatory pathways involving interferon signaling and cell junctions were altered. DNA repair and cell adhesion molecules were affected by 124 mGy of radiation while DNA synthesis, apoptosis, metabolism, and neural differentiation were all affected by 496 mGy of radiation. These in vitro results suggest that 496 mGy radiation affects the development of neuronal progenitor cells while altered gene expression was observed at a radiation dose lower than 100 mGy. This study would contribute to the elucidation of the clinical and subclinical phenotypes of impaired neuronal development induced by chronic low-dose radiation.

  19. Effects of Chronic Low-Dose Radiation on Human Neural Progenitor Cells

    PubMed Central

    Katsura, Mari; Cyou-Nakamine, Hiromasa; Zen, Qin; Zen, Yang; Nansai, Hiroko; Amagasa, Shota; Kanki, Yasuharu; Inoue, Tsuyoshi; Kaneki, Kiyomi; Taguchi, Akashi; Kobayashi, Mika; Kaji, Toshiyuki; Kodama, Tatsuhiko; Miyagawa, Kiyoshi; Wada, Youichiro; Akimitsu, Nobuyoshi; Sone, Hideko

    2016-01-01

    The effects of chronic low-dose radiation on human health have not been well established. Recent studies have revealed that neural progenitor cells are present not only in the fetal brain but also in the adult brain. Since immature cells are generally more radiosensitive, here we investigated the effects of chronic low-dose radiation on cultured human neural progenitor cells (hNPCs) derived from embryonic stem cells. Radiation at low doses of 31, 124 and 496 mGy per 72 h was administered to hNPCs. The effects were estimated by gene expression profiling with microarray analysis as well as morphological analysis. Gene expression was dose-dependently changed by radiation. By thirty-one mGy of radiation, inflammatory pathways involving interferon signaling and cell junctions were altered. DNA repair and cell adhesion molecules were affected by 124 mGy of radiation while DNA synthesis, apoptosis, metabolism, and neural differentiation were all affected by 496 mGy of radiation. These in vitro results suggest that 496 mGy radiation affects the development of neuronal progenitor cells while altered gene expression was observed at a radiation dose lower than 100 mGy. This study would contribute to the elucidation of the clinical and subclinical phenotypes of impaired neuronal development induced by chronic low-dose radiation. PMID:26795421

  20. Estimation of Effective Doses for Radiation Cancer Risks on ISS, Lunar, and Mars Missions with Space Radiation Measurement

    NASA Technical Reports Server (NTRS)

    Kim, M.Y.; Cucinotta, F.A.

    2005-01-01

    Radiation protection practices define the effective dose as a weighted sum of equivalent dose over major sites for radiation cancer risks. Since a crew personnel dosimeter does not make direct measurement of effective dose, it has been estimated with skin-dose measurements and radiation transport codes for ISS and STS missions. The Phantom Torso Experiment (PTE) of NASA s Operational Radiation Protection Program has provided the actual flight measurements of active and passive dosimeters which were placed throughout the phantom on STS-91 mission for 10 days and on ISS Increment 2 mission. For the PTE, the variation in organ doses, which is resulted by the absorption and the changes in radiation quality with tissue shielding, was considered by measuring doses at many tissue sites and at several critical body organs including brain, colon, heart, stomach, thyroid, and skins. These measurements have been compared with the organ dose calculations obtained from the transport models. Active TEPC measurements of lineal energy spectra at the surface of the PTE also provided the direct comparison of galactic cosmic ray (GCR) or trapped proton dose and dose equivalent. It is shown that orienting the phantom body as actual in ISS is needed for the direct comparison of the transport models to the ISS data. One of the most important observations for organ dose equivalent of effective dose estimates on ISS is the fractional contribution from trapped protons and GCR. We show that for most organs over 80% is from GCR. The improved estimation of effective doses for radiation cancer risks will be made with the resultant tissue weighting factors and the modified codes.

  1. Source term calculations for assessing radiation dose to equipment

    SciTech Connect

    Denning, R.S.; Freeman-Kelly, R.; Cybulskis, P.; Curtis, L.A.

    1989-07-01

    This study examines results of analyses performed with the Source Term Code Package to develop updated source terms using NUREG-0956 methods. The updated source terms are to be used to assess the adequacy of current regulatory source terms used as the basis for equipment qualification. Time-dependent locational distributions of radionuclides within a containment following a severe accident have been developed. The Surry reactor has been selected in this study as representative of PWR containment designs. Similarly, the Peach Bottom reactor has been used to examine radionuclide distributions in boiling water reactors. The time-dependent inventory of each key radionuclide is provided in terms of its activity in curies. The data are to be used by Sandia National Laboratories to perform shielding analyses to estimate radiation dose to equipment in each containment design. See NUREG/CR-5175, Beta and Gamma Dose Calculations for PWR and BWR Containments.'' 6 refs., 11 tabs.

  2. 42 CFR 82.4 - How Will DOL Use the Results of the NIOSH Dose Reconstructions?

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Will DOL Use the Results of the NIOSH Dose Reconstructions? Under 42 CFR part 81, DOL will apply dose reconstruction results together with information on cancer diagnosis and other personal information provided to... probability that the cancer of the covered employee was caused by radiation exposure at a covered facility...

  3. 42 CFR 82.4 - How Will DOL Use the Results of the NIOSH Dose Reconstructions?

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Will DOL Use the Results of the NIOSH Dose Reconstructions? Under 42 CFR part 81, DOL will apply dose reconstruction results together with information on cancer diagnosis and other personal information provided to... probability that the cancer of the covered employee was caused by radiation exposure at a covered facility...

  4. 42 CFR 82.4 - How Will DOL Use the Results of the NIOSH Dose Reconstructions?

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Will DOL Use the Results of the NIOSH Dose Reconstructions? Under 42 CFR part 81, DOL will apply dose reconstruction results together with information on cancer diagnosis and other personal information provided to... probability that the cancer of the covered employee was caused by radiation exposure at a covered facility...

  5. 42 CFR 82.4 - How Will DOL Use the Results of the NIOSH Dose Reconstructions?

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Will DOL Use the Results of the NIOSH Dose Reconstructions? Under 42 CFR part 81, DOL will apply dose reconstruction results together with information on cancer diagnosis and other personal information provided to... probability that the cancer of the covered employee was caused by radiation exposure at a covered facility...

  6. 42 CFR 82.4 - How Will DOL Use the Results of the NIOSH Dose Reconstructions?

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Will DOL Use the Results of the NIOSH Dose Reconstructions? Under 42 CFR part 81, DOL will apply dose reconstruction results together with information on cancer diagnosis and other personal information provided to... probability that the cancer of the covered employee was caused by radiation exposure at a covered facility...

  7. Galactic cosmic radiation doses to astronauts outside the magnetosphere

    SciTech Connect

    Letaw, J.R.

    1987-12-06

    The dose and dose equivalent from galactic cosmic radiation outside the magnetosphere were computed. The principal radiation components considered include primary cosmic rays, spallation fragments of the heavy ions, and secondary products (protons, neutrons, alphas, and recoil nuclei) from interactions in tissue. Three mission environments were considered: free space, the lunar surface, and the martian surface. The annual dose equivalents to the blood-forming organs in these environments are approximately 500 mSv, 250 mSv, and 120 mSv, respectively (1 mSv = 0.1 rem). The dose on the lunar surface is one-half of free space because there is only a single hemisphere of exposure. The dose on the martian surface is half again the dose on the moon because of the shielding provided by a thin, carbon dioxide atmosphere. Dose versus aluminum shielding thickness functions have been computed for the free space exposure. Galactic cosmic radiation is energetic and highly penetrating. 30 cm of aluminum shielding reduces the dose equivalent 25% to 40% (depending on the phase of the solar cycle). Aiming for conformity with the draft NCRP annual dose limit for space station crew members, which is 500 mSv/yr, we recommend 7.5 cm of aluminum shielding in all habitable areas of spacecraft designed for long-duration missions outside Earth's magnetosphere. This shielding thickness reduces the galactic cosmic ray dose and diminishes the risk to astronauts from energetic particle events.

  8. Breast tomography with synchrotron radiation: preliminary results

    NASA Astrophysics Data System (ADS)

    Pani, Silvia; Longo, Renata; Dreossi, Diego; Montanari, Francesco; Olivo, Alessandro; Arfelli, Fulvia; Bergamaschi, Anna; Poropat, Paolo; Rigon, Luigi; Zanconati, Fabrizio; Dalla Palma, Ludovico; Castelli, Edoardo

    2004-05-01

    A system for in vivo breast imaging with monochromatic x-rays has been designed and built at the synchrotron radiation facility Elettra in Trieste (Italy) and will be operational in 2004. The system design involves the possibility of performing both planar mammography and breast tomography. In the present work, the first results obtained with a test set-up for breast tomography are shown and discussed. Tomographic images of in vitro breasts were acquired using monochromatic x-ray beams in the energy range 20-28 keV and a linear array silicon pixel detector. Tomograms were reconstructed using standard filtered backprojection algorithms; the effect of different filters was evaluated. The attenuation coefficients of fibroglandular and adipose tissue were measured, and a quantitative comparison of images acquired at different energies was performed by calculating the differential signal-to-noise ratio of fibroglandular details in adipose tissue. All images required a dose comparable to the dose delivered in clinical, conventional mammography and showed a high resolution of the breast structures without the overlapping effects that limit the visibility of the structures in 2D mammography. A quantitative evaluation of the images proves that the image quality at a given dose increases in the considered energy range and for the considered breast sizes. This work is dedicated to the memory of Paolo Poropat, who died tragically on June 8th, 2002. He was a brilliant experimental scientist and gave relevant contributions to the fields of high energy physics and medical physics. He had a very rich and versatile personality, a brilliant character, a big vitality. We will never forget him, his love of life, the passion and the enthusiasm he put into everything he did.

  9. Radiation dose and image quality for paediatric interventional cardiology

    NASA Astrophysics Data System (ADS)

    Vano, E.; Ubeda, C.; Leyton, F.; Miranda, P.

    2008-08-01

    Radiation dose and image quality for paediatric protocols in a biplane x-ray system used for interventional cardiology have been evaluated. Entrance surface air kerma (ESAK) and image quality using a test object and polymethyl methacrylate (PMMA) phantoms have been measured for the typical paediatric patient thicknesses (4-20 cm of PMMA). Images from fluoroscopy (low, medium and high) and cine modes have been archived in digital imaging and communications in medicine (DICOM) format. Signal-to-noise ratio (SNR), figure of merit (FOM), contrast (CO), contrast-to-noise ratio (CNR) and high contrast spatial resolution (HCSR) have been computed from the images. Data on dose transferred to the DICOM header have been used to test the values of the dosimetric display at the interventional reference point. ESAK for fluoroscopy modes ranges from 0.15 to 36.60 µGy/frame when moving from 4 to 20 cm PMMA. For cine, these values range from 2.80 to 161.10 µGy/frame. SNR, FOM, CO, CNR and HCSR are improved for high fluoroscopy and cine modes and maintained roughly constant for the different thicknesses. Cumulative dose at the interventional reference point resulted 25-45% higher than the skin dose for the vertical C-arm (depending of the phantom thickness). ESAK and numerical image quality parameters allow the verification of the proper setting of the x-ray system. Knowing the increases in dose per frame when increasing phantom thicknesses together with the image quality parameters will help cardiologists in the good management of patient dose and allow them to select the best imaging acquisition mode during clinical procedures.

  10. Intensity Modulated Radiation Therapy With Dose Painting to Treat Rhabdomyosarcoma

    SciTech Connect

    Yang, Joanna C.; Dharmarajan, Kavita V.; Wexler, Leonard H.; La Quaglia, Michael P.; Happersett, Laura; Wolden, Suzanne L.

    2012-11-01

    Purpose: To examine local control and patterns of failure in rhabdomyosarcoma patients treated with intensity modulated radiation therapy (RT) with dose painting (DP-IMRT). Patients and Methods: A total of 41 patients underwent DP-IMRT with chemotherapy for definitive treatment. Nineteen also underwent surgery with or without intraoperative RT. Fifty-six percent had alveolar histologic features. The median interval from beginning chemotherapy to RT was 17 weeks (range, 4-25). Very young children who underwent second-look procedures with or without intraoperative RT received reduced doses of 24-36 Gy in 1.4-1.8-Gy fractions. Young adults received 50.4 Gy to the primary tumor and lower doses of 36 Gy in 1.8-Gy fractions to at-risk lymph node chains. Results: With 22 months of median follow-up, the actuarial local control rate was 90%. Patients aged {<=}7 years who received reduced overall and fractional doses had 100% local control, and young adults had 79% (P=.07) local control. Three local failures were identified in young adults whose primary target volumes had received 50.4 Gy in 1.8-Gy fractions. Conclusions: DP-IMRT with lower fractional and cumulative doses is feasible for very young children after second-look procedures with or without intraoperative RT. DP-IMRT is also feasible in adolescents and young adults with aggressive disease who would benefit from prophylactic RT to high-risk lymph node chains, although dose escalation might be warranted for improved local control. With limited follow-up, it appears that DP-IMRT produces local control rates comparable to those of sequential IMRT in patients with rhabdomyosarcoma.

  11. Method for inserting noise in digital mammography to simulate reduction in radiation dose

    NASA Astrophysics Data System (ADS)

    Borges, Lucas R.; de Oliveira, Helder C. R.; Nunes, Polyana F.; Vieira, Marcelo A. C.

    2015-03-01

    The quality of clinical x-ray images is closely related to the radiation dose used in the imaging study. The general principle for selecting the radiation is ALARA ("as low as reasonably achievable"). The practical optimization, however, remains challenging. It is well known that reducing the radiation dose increases the quantum noise, which could compromise the image quality. In order to conduct studies about dose reduction in mammography, it would be necessary to acquire repeated clinical images, from the same patient, with different dose levels. However, such practice would be unethical due to radiation related risks. One solution is to simulate the effects of dose reduction in clinical images. This work proposes a new method, based on the Anscombe transformation, which simulates dose reduction in digital mammography by inserting quantum noise into clinical mammograms acquired with the standard radiation dose. Thus, it is possible to simulate different levels of radiation doses without exposing the patient to new levels of radiation. Results showed that the achieved quality of simulated images generated with our method is the same as when using other methods found in the literature, with the novelty of using the Anscombe transformation for converting signal-independent Gaussian noise into signal-dependent quantum noise.

  12. Methodology for estimating radiation dose rates to freshwater biota exposed to radionuclides in the environment

    SciTech Connect

    Blaylock, B.G.; Frank, M.L.; O`Neal, B.R.

    1993-08-01

    The purpose of this report is to present a methodology for evaluating the potential for aquatic biota to incur effects from exposure to chronic low-level radiation in the environment. Aquatic organisms inhabiting an environment contaminated with radioactivity receive external radiation from radionuclides in water, sediment, and from other biota such as vegetation. Aquatic organisms receive internal radiation from radionuclides ingested via food and water and, in some cases, from radionuclides absorbed through the skin and respiratory organs. Dose rate equations, which have been developed previously, are presented for estimating the radiation dose rate to representative aquatic organisms from alpha, beta, and gamma irradiation from external and internal sources. Tables containing parameter values for calculating radiation doses from selected alpha, beta, and gamma emitters are presented in the appendix to facilitate dose rate calculations. The risk of detrimental effects to aquatic biota from radiation exposure is evaluated by comparing the calculated radiation dose rate to biota to the U.S. Department of Energy`s (DOE`s) recommended dose rate limit of 0.4 mGy h{sup {minus}1} (1 rad d{sup {minus}1}). A dose rate no greater than 0.4 mGy h{sup {minus}1} to the most sensitive organisms should ensure the protection of populations of aquatic organisms. DOE`s recommended dose rate is based on a number of published reviews on the effects of radiation on aquatic organisms that are summarized in the National Council on Radiation Protection and Measurements Report No. 109 (NCRP 1991). DOE recommends that if the results of radiological models or dosimetric measurements indicate that a radiation dose rate of 0. 1 mGy h{sup {minus}1} will be exceeded, then a more detailed evaluation of the potential ecological consequences of radiation exposure to endemic populations should be conducted.

  13. Radiation dose in the high background radiation area in Kerala, India.

    PubMed

    Christa, E P; Jojo, P J; Vaidyan, V K; Anilkumar, S; Eappen, K P

    2012-03-01

    A systematic radiological survey has been carried out in the region of high-background radiation area in Kollam district of Kerala to define the natural gamma-radiation levels. One hundred and forty seven soil samples from high-background radiation areas and five samples from normal background region were collected as per standard sampling procedures and were analysed for (238)U, (232)Th and (40)K by gamma-ray spectroscopy. External gamma dose rates at all sampling locations were also measured using a survey meter. The activities of (238)U, (232)Th and (40)K was found to vary from 17 to 3081 Bq kg(-1), 54 to 11976 Bq kg(-1) and BDL (67.4 Bq kg(-1)) to 216 Bq kg(-1), respectively, in the study area. Such heterogeneous distribution of radionuclides in the region may be attributed to the deposition phenomenon of beach sand soil in the region. Radium equivalent activities were found high in several locations. External gamma dose rates estimated from the levels of radionuclides in soil had a range from 49 to 9244 nGy h(-1). The result of gamma dose rate measured at the sampling sites using survey meter showed an excellent correlation with dose rates computed from the natural radionuclides estimated from the soil samples. PMID:21515614

  14. High and Low Doses of Ionizing Radiation Induce Different Secretome Profiles in a Human Skin Model

    SciTech Connect

    Zhang, Qibin; Matzke, Melissa M.; Schepmoes, Athena A.; Moore, Ronald J.; Webb-Robertson, Bobbie-Jo M.; Hu, Zeping; Monroe, Matthew E.; Qian, Weijun; Smith, Richard D.; Morgan, William F.

    2014-03-18

    It is postulated that secreted soluble factors are important contributors of bystander effect and adaptive responses observed in low dose ionizing radiation. Using multidimensional liquid chromatography-mass spectrometry based proteomics, we quantified the changes of skin tissue secretome – the proteins secreted from a full thickness, reconstituted 3-dimensional skin tissue model 48 hr after exposure to 3, 10 and 200 cGy of X-rays. Overall, 135 proteins showed statistical significant difference between the sham (0 cGy) and any of the irradiated groups (3, 10 or 200 cGy) on the basis of Dunnett adjusted t-test; among these, 97 proteins showed a trend of downregulation and 9 proteins showed a trend of upregulation with increasing radiation dose. In addition, there were 21 and 8 proteins observed to have irregular trends with the 10 cGy irradiated group either having the highest or the lowest level among all three radiated doses. Moreover, two proteins, carboxypeptidase E and ubiquitin carboxyl-terminal hydrolase isozyme L1 were sensitive to ionizing radiation, but relatively independent of radiation dose. Conversely, proteasome activator complex subunit 2 protein appeared to be sensitive to the dose of radiation, as rapid upregulation of this protein was observed when radiation doses were increased from 3, to 10 or 200 cGy. These results suggest that different mechanisms of action exist at the secretome level for low and high doses of ionizing radiation.

  15. Effects Of Dose Rates On Radiation Damage In CMOS Parts

    NASA Technical Reports Server (NTRS)

    Goben, Charles A.; Coss, James R.; Price, William E.

    1990-01-01

    Report describes measurements of effects of ionizing-radiation dose rate on consequent damage to complementary metal oxide/semiconductor (CMOS) electronic devices. Depending on irradiation time and degree of annealing, survivability of devices in outer space, or after explosion of nuclear weapons, enhanced. Annealing involving recovery beyond pre-irradiation conditions (rebound) detrimental. Damage more severe at lower dose rates.

  16. Radiation dose modeling using IGRIP and Deneb/ERGO

    SciTech Connect

    Vickers, D.S.; Davis, K.R.; Breazeal, N.L.; Watson, R.A.; Ford, M.S.

    1995-12-31

    The Radiological Environment Modeling System (REMS) quantifies dose to humans in radiation environments using the IGRIP (Interactive Graphical Robot Instruction Program) and Deneb/ERGO (Ergonomics) simulation software products. These commercially available products are augmented with custom C code to provide the radiation exposure information to and collect the radiation dose information from the workcell simulations. The emphasis of this paper is on the IGRIP and Deneb/ERGO parts of REMS, since that represents the extension to existing capabilities developed by the authors. Through the use of any radiation transport code or measured data, a radiation exposure input database may be formulated. User-specified IGRIP simulations utilize these database files to compute and accumulate dose to human devices (Deneb`s ERGO human) during simulated operations around radiation sources. Timing, distances, shielding, and human activity may be modeled accurately in the simulations. The accumulated dose is recorded in output files, and the user is able to process and view this output. REMS was developed because the proposed reduction in the yearly radiation exposure limit will preclude or require changes in many of the manual operations currently being utilized in the Weapons Complex. This is particularly relevant in the area of dismantlement activities at the Pantex Plant in Amarillo, TX. Therefore, a capability was needed to be able to quantify the dose associated with certain manual processes so that the benefits of automation could be identified and understood.

  17. Radiation dose to the lens and cataract formation

    SciTech Connect

    Henk, J.M.; Whitelocke, R.A.F.; Warrington, A.P.; Bessell, E.M. )

    1993-04-02

    The purpose of this work was to determine the radiation tolerance of the lens of the eye and the incidence of radiation-induced lens changes in patients treated by fractionated supervoltage radiation therapy for orbital tumors. Forty patients treated for orbital lymphoma and pseudotumor with tumor doses of 20--40 Gy were studied. The lens was partly shielded using lead cylinders in most cases. The dose to the germinative zone of the lens was estimated by measurements in a tissue equivalent phantom using both film densitometry and thermoluminescent dosimetry. Opthalmological examination was performed at 6 monthly intervals after treatment. The lead shield was found to reduce the dose to the germinative zone of the lens to between 36--50% of the tumor dose for Cobalt beam therapy, and to between 11--18% for 5 MeV x-rays. Consequently, the lens doses were in the range 4.5--30 Gy in 10--20 fractions. Lens opacities first appeared from between 3 and 9 years after irradiation. Impairment of visual acuity ensued in 74% of the patients who developed lens opacities. The incidence of lens changes was strongly dose-related. None was seen after doses of 5 Gy or lower, whereas doses of 16.5 Gy or higher were all followed by lens opacities which impaired visual acuity. The largest number of patients received a maximum lens dose of 15 Gy; in this group the actuarial incidence of lens opacities at 8 years was 57% with visual impairment in 38%. The adult lens can tolerate a total dose of 5 Gy during a fractionated course of supervoltage radiation therapy without showing any changes. Doses of 16.5 Gy or higher will almost invariably lead to visual impairment. The dose which causes a 50% probability of visual impairment is approximately 15 Gy. 10 refs., 4 figs., 1 tab.

  18. Fetal radiation dose in computed tomography.

    PubMed

    Kelaranta, Anna; Kaasalainen, Touko; Seuri, Raija; Toroi, Paula; Kortesniemi, Mika

    2015-07-01

    The connection between recorded volumetric CT dose index (CTDI vol) and determined mean fetal dose (Df) was examined from metal-oxide-semiconductor field-effect transistor dose measurements on an anthropomorphic female phantom in four stages of pregnancy in a 64-slice CT scanner. Automated tube current modulation kept the mean Df fairly constant through all pregnancy stages in trauma (4.4-4.9 mGy) and abdomino-pelvic (2.1-2.4 mGy) protocols. In pulmonary angiography protocol, the mean Df increased exponentially as the distance from the end of the scan range decreased (0.01-0.09 mGy). For trauma protocol, the relative mean Df as a function of gestational age were in the range 0.80-0.97 compared with the mean CTDI vol. For abdomino-pelvic protocol, the relative mean Df was 0.57-0.79 and for pulmonary angiography protocol, 0.01-0.05 compared with the mean CTDI vol, respectively. In conclusion, if the fetus is in the primary beam, the CTDI vol can be used as an upper estimate of the fetal dose. If the fetus is not in the primary beam, the fetal dose can be estimated by considering also the distance of the fetus from the scan range. PMID:25836690

  19. A Raman spectroscopic study of cell response to clinical doses of ionizing radiation.

    PubMed

    Harder, Samantha J; Matthews, Quinn; Isabelle, Martin; Brolo, Alexandre G; Lum, Julian J; Jirasek, Andrew

    2015-01-01

    The drive toward personalized radiation therapy (RT) has created significant interest in determining patient-specific tumor and normal tissue responses to radiation. Raman spectroscopy (RS) is a non-invasive and label-free technique that can detect radiation response through assessment of radiation-induced biochemical changes in tumor cells. In the current study, single-cell RS identified specific radiation-induced responses in four human epithelial tumor cell lines: lung (H460), breast (MCF-7, MDA-MB-231), and prostate (LNCaP), following exposure to clinical doses of radiation (2-10 Gy). At low radiation doses (2 Gy), H460 and MCF-7 cell lines showed an increase in glycogen-related spectral features, and the LNCaP cell line showed a membrane phospholipid-related radiation response. In these cell lines, only spectral information from populations receiving 10 Gy or less was required to identify radiation-related features using principal component analysis (PCA). In contrast, the MDA-MB-231 cell line showed a significant increase in protein relative to nucleic acid and lipid spectral features at doses of 6 Gy or higher, and high-dose information (30, 50 Gy) was required for PCA to identify this biological response. The biochemical nature of the radiation-related changes occurring in cells exposed to clinical doses was found to segregate by status of p53 and radiation sensitivity. Furthermore, the utility of RS to identify a biological response in human tumor cells exposed to therapeutic doses of radiation was found to be governed by the extent of the biochemical changes induced by a radiation response and is therefore cell line specific. The results of this study demonstrate the utility and effectiveness of single-cell RS to identify and measure biological responses in tumor cells exposed to standard radiotherapy doses. PMID:25588147

  20. Radiation Dose-Response Relationships and Risk Assessment

    SciTech Connect

    Strom, Daniel J.

    2005-07-05

    The notion of a dose-response relationship was probably invented shortly after the discovery of poisons, the invention of alcoholic beverages, and the bringing of fire into a confined space in the forgotten depths of ancient prehistory. The amount of poison or medicine ingested can easily be observed to affect the behavior, health, or sickness outcome. Threshold effects, such as death, could be easily understood for intoxicants, medicine, and poisons. As Paracelsus (1493-1541), the 'father' of modern toxicology said, 'It is the dose that makes the poison.' Perhaps less obvious is the fact that implicit in such dose-response relationships is also the notion of dose rate. Usually, the dose is administered fairly acutely, in a single injection, pill, or swallow; a few puffs on a pipe; or a meal of eating or drinking. The same amount of intoxicants, medicine, or poisons administered over a week or month might have little or no observable effect. Thus, before the discovery of ionizing radiation in the late 19th century, toxicology ('the science of poisons') and pharmacology had deeply ingrained notions of dose-response relationships. This chapter demonstrates that the notion of a dose-response relationship for ionizing radiation is hopelessly simplistic from a scientific standpoint. While useful from a policy or regulatory standpoint, dose-response relationships cannot possibly convey enough information to describe the problem from a quantitative view of radiation biology, nor can they address societal values. Three sections of this chapter address the concepts, observations, and theories that contribute to the scientific input to the practice of managing risks from exposure to ionizing radiation. The presentation begins with irradiation regimes, followed by responses to high and low doses of ionizing radiation, and a discussion of how all of this can inform radiation risk management. The knowledge that is really needed for prediction of individual risk is presented

  1. NAIRAS aircraft radiation model development, dose climatology, and initial validation

    NASA Astrophysics Data System (ADS)

    Mertens, Christopher J.; Meier, Matthias M.; Brown, Steven; Norman, Ryan B.; Xu, Xiaojing

    2013-10-01

    The Nowcast of Atmospheric Ionizing Radiation for Aviation Safety (NAIRAS) is a real-time, global, physics-based model used to assess radiation exposure to commercial aircrews and passengers. The model is a free-running physics-based model in the sense that there are no adjustment factors applied to nudge the model into agreement with measurements. The model predicts dosimetric quantities in the atmosphere from both galactic cosmic rays (GCR) and solar energetic particles, including the response of the geomagnetic field to interplanetary dynamical processes and its subsequent influence on atmospheric dose. The focus of this paper is on atmospheric GCR exposure during geomagnetically quiet conditions, with three main objectives. First, provide detailed descriptions of the NAIRAS GCR transport and dosimetry methodologies. Second, present a climatology of effective dose and ambient dose equivalent rates at typical commercial airline altitudes representative of solar cycle maximum and solar cycle minimum conditions and spanning the full range of geomagnetic cutoff rigidities. Third, conduct an initial validation of the NAIRAS model by comparing predictions of ambient dose equivalent rates with tabulated reference measurement data and recent aircraft radiation measurements taken in 2008 during the minimum between solar cycle 23 and solar cycle 24. By applying the criterion of the International Commission on Radiation Units and Measurements (ICRU) on acceptable levels of aircraft radiation dose uncertainty for ambient dose equivalent greater than or equal to an annual dose of 1 mSv, the NAIRAS model is within 25% of the measured data, which fall within the ICRU acceptable uncertainty limit of 30%. The NAIRAS model predictions of ambient dose equivalent rate are generally within 50% of the measured data for any single-point comparison. The largest differences occur at low latitudes and high cutoffs, where the radiation dose level is low. Nevertheless, analysis suggests

  2. Malignant melanoma of the tongue following low-dose radiation

    SciTech Connect

    Kalemeris, G.C.; Rosenfeld, L.; Gray, G.F. Jr.; Glick, A.D.

    1985-03-01

    A 47-year-old man had a spindly malignant melanoma of the tongue many years after low-dose radiation therapy for lichen planus. To our knowledge, only 12 melanomas of the tongue have been reported previously, and in none of these was radiation documented.

  3. Treatment planning and dose calculation in radiation ecology

    SciTech Connect

    Bentel, G.C.; Nelson, C.E.; Noell, K.T.

    1989-01-01

    This book focuses on treatment planning of cancer therapy. The following topics are discussed: elements of clinical radiation oncology; radiation physics; dose calculation for external beams; pretreatment procedures; brachytherapy; principles of external beam treatment planning; practical treatment planning; and normal tissue consequences. Eight chapters have been processed separately for inclusion in the appropriate data bases.

  4. Radiation Dose from Lunar Neutron Albedo

    NASA Technical Reports Server (NTRS)

    Adams, J. H., Jr.; Bhattacharya, M.; Lin, Zi-Wei; Pendleton, G.

    2006-01-01

    The lunar neutron albedo from thermal energies to 8 MeV was measured on the Lunar Prospector Mission in 1998-1999. Using GEANT4 we have calculated the neutron albedo due to cosmic ray bombardment of the moon and found a good-agreement with the measured fast neutron spectra. We then calculated the total effective dose from neutron albedo of all energies, and made comparisons with the effective dose contributions from both galactic cosmic rays and solar particle events to be expected on the lunar surface.

  5. Radiation Doses to Hanford Workers from Natural Potassium-40

    SciTech Connect

    Strom, Daniel J.; Lynch, Timothy P.; Weier, Dennis R.

    2009-02-01

    The chemical element potassium is an essential mineral in people and is subject to homeostatic regulation. Natural potassium comprises three isotopes, 39K, 40K, and 41K. Potassium-40 is radioactive, with a half life of 1.248 billion years. In most transitions, it emits a β particle with a maximum energy of 0.560 MeV, and sometimes a gamma photon of 1.461 MeV. Because it is ubiquitous, 40K produces radiation dose to all human beings. This report contains the results of new measurements of 40K in 248 adult females and 2,037 adult males performed at the Department of Energy Hanford Site in 2006 and 2007. Potassium concentrations diminish with age, are generally lower in women than in men, and decrease with body mass index (BMI). The average annual effective dose from 40K in the body is 0.149 mSv y-1 for men and 0.123 mSv y-1 women respectively. Averaged over both men and women, the average effective dose per year is 0.136 mSv y-1. Calculated effective doses range from 0.069 to 0.243 mSv y-1 for adult males, and 0.067 to 0.203 mSv y-1 for adult females, a roughly three-fold variation for each gender. The need for dosimetric phantoms with a greater variety of BMI values should be investigated. From our data, it cannot be determined whether the potassium concentration in muscle in people with large BMI values differs from that in people with small BMI values. Similarly, it would be important to know the potassium concentration in other soft tissues, since much of the radiation dose is due to beta radiation, in which the source and target tissues are the same. These uncertainties should be evaluated to determine their consequences for dosimetry.

  6. Individual and collective doses from cosmic radiation in Ireland.

    PubMed

    Colgan, P A; Synnott, H; Fenton, D

    2007-01-01

    This paper assesses the individual and collective doses in Ireland due to cosmic radiation. Information on the exposure to cosmic radiation at ground level is reviewed and published data on the frequency of routes flown by Irish residents is used to calculate the dose due to air travel. Occupational exposure of aircrew is also evaluated. Experimental data on cosmic radiation exposure at ground level is in good agreement with international estimates and the average individual dose is calculated as 300 microSv annually. Published data on international air travel by Irish residents shows a 50% increase in the number of flights taken between 2001 and 2005. This increase is primarily on short-haul flights to Europe, but there have been significant percentage increases in all long-haul flights, with the exception of flights to Africa. The additional per capita dose due to air travel is estimated to be 45 muSv, of which 51% is accumulated on European routes and 34% on routes to the United States. Exposure of aircrew to cosmic radiation is now controlled by legislation and all airlines holding an Air Operator's Certificate issued by the Irish Aviation Authority are required to report annually the doses received by their employees in the previous year. There has been a 75% increase in the number of aircrew receiving doses >1 mSv since 2002. In 2004 and 2005 the average individual doses received by Irish aircrew were 1.8 and 2.0, mSv, respectively. The corresponding per caput dose for the entire population is <3 muSv. While this is low compared with the per caput doses from other sources of cosmic radiation, aircrew exposure represents a higher collective dose than any other identified group of exposed workers in Ireland. PMID:17223639

  7. Reduction of radiation dose to patients undergoing barium enema by dose audit.

    PubMed

    Yu, S K; Cheung, Y K; Chan, T L; Kung, C M; Yuen, M K

    2001-02-01

    Nowadays, new fluoroscopic machines are usually equipped with a dose-area product (DAP) meter for dose measurement. In our hospital, DAP meters have been used in the Diagnostic Radiology Department for dose audit since June 1997. Demographic patient data, name of radiologist, fluoroscopic duration and DAP readings of every case were recorded by radiographers. In early 1999, questionnaires were distributed to radiologists who had performed fluoroscopic examinations during the auditing period. 23 radiologists with varying years of experience completed the questionnaire and their practice was analysed. Since familiarization with the examination technique would affect radiologists' practice, these radiologists were divided into two groups for analysis. Radiologists with less than 3 years of experience were grouped together as junior radiologists, whilst others were grouped as senior radiologists. Results of the questionnaire indicated that radiologists generally found DAP meters useful for dose evaluation in the process of technique refinement. Radiologists aware of being under continuous surveillance of their practice showed significant reduction of doses (junior radiologists 25%, p<0.005; senior radiologists 36%, p<0.05) and fluoroscopic times (junior radiologists 36%, p<0.001; senior radiologists 18%, p<0.05) compared with radiologists who were unaware that they were under surveillance but with similar radiological experience. This effect is believed to be because of increased awareness of radiation dose through audit. In addition, this "audit effect" may also affect junior radiologists in decision-making regarding the number of radiographs (p<0.05), but no effect was found for senior radiologists (p>0.5). PMID:11718389

  8. Differential Response and Priming Dose Effect on the Proteome of Human Fibroblast and Stem Cells Induced by Exposure to Low Doses of Ionizing Radiation.

    PubMed

    Hauptmann, Monika; Haghdoost, Siamak; Gomolka, Maria; Sarioglu, Hakan; Ueffing, Marius; Dietz, Anne; Kulka, Ulrike; Unger, Kristian; Babini, Gabriele; Harms-Ringdahl, Mats; Ottolenghi, Andrea; Hornhardt, Sabine

    2016-03-01

    It has been suggested that a mechanistic understanding of the cellular responses to low dose and dose rate may be valuable in reducing some of the uncertainties involved in current risk estimates for cancer- and non-cancer-related radiation effects that are inherited in the linear no-threshold hypothesis. In this study, the effects of low-dose radiation on the proteome in both human fibroblasts and stem cells were investigated. Particular emphasis was placed on examining: 1. the dose-response relationships for the differential expression of proteins in the low-dose range (40-140 mGy) of low-linear energy transfer (LET) radiation; and 2. the effect on differential expression of proteins of a priming dose given prior to a challenge dose (adaptive response effects). These studies were performed on cultured human fibroblasts (VH10) and human adipose-derived stem cells (ADSC). The results from the VH10 cell experiments demonstrated that low-doses of low-LET radiation induced unique patterns of differentially expressed proteins for each dose investigated. In addition, a low priming radiation dose significantly changed the protein expression induced by the subsequent challenge exposure. In the ADSC the number of differentially expressed proteins was markedly less compared to VH10 cells, indicating that ADSC differ in their intrinsic response to low doses of radiation. The proteomic results are further discussed in terms of possible pathways influenced by low-dose irradiation. PMID:26934482

  9. Approaches to reducing radiation dose from radionuclide myocardial perfusion imaging.

    PubMed

    Dorbala, Sharmila; Blankstein, Ron; Skali, Hicham; Park, Mi-Ae; Fantony, Jolene; Mauceri, Charles; Semer, James; Moore, Stephen C; Di Carli, Marcelo F

    2015-04-01

    Radionuclide myocardial perfusion imaging (MPI) plays a vital role in the evaluation and management of patients with coronary artery disease. However, because of a steep growth in MPI in the mid 2000s, concerns about inappropriate use of MPI and imaging-related radiation exposure increased. In response, the professional societies developed appropriate-use criteria for MPI. Simultaneously, novel technology, image-reconstruction software for traditional scanners, and dedicated cardiac scanners emerged and facilitated the performance of MPI with low-dose and ultra-low-dose radiotracers. This paper provides a practical approach to performing low-radiation-dose MPI using traditional and novel technologies. PMID:25766891

  10. Perception of Radiation Risk by Japanese Radiation Specialists Evaluated as a Safe Dose Before the Fukushima Nuclear Accident.

    PubMed

    Miura, Miwa; Ono, Koji; Yamauchi, Motohiro; Matsuda, Naoki

    2016-06-01

    From October to December 2010, just before the radiological accident at the Fukushima Daiichi nuclear power plant, 71 radiation professionals from radiation facilities in Japan were asked what they considered as a "safe dose" of radiation for themselves, their partners, parents, children, siblings, and friends. Although the 'safe dose' they noted varied widely, from less than 1 mSv y to more than 100 mSv y, the average dose was 35.6 mSv y, which is around the middle point between the legal exposure dose limits for the annual average and for any single year. Similar results were obtained from other surveys of members of the Japan Radioisotope Association (36.9 mSv y) and of the Oita Prefectural Hospital (36.8 mSv y). Among family members and friends, the minimum average "safe" dose was 8.5 mSv y for children, for whom 50% of the responders claimed a "safe dose" of less than 1 mSv. Gender, age and specialty of the radiation professional also affected their notion of a "safe dose." These findings suggest that the perception of radiation risk varies widely even for radiation professionals and that the legal exposure dose limits derived from regulatory science may act as an anchor of safety. The different levels of risk perception for different target groups among radiation professionals appear similar to those in the general population. The gap between these characteristics of radiation professionals and the generally accepted picture of radiation professionals might have played a role in the state of confusion after the radiological accident. PMID:27115222

  11. High and low dose radiation effects on mammary adenocarcinoma cells – an epigenetic connection

    PubMed Central

    Luzhna, Lidia; Filkowski, Jody; Kovalchuk, Olga

    2016-01-01

    The successful treatment of cancer, including breast cancer, depends largely on radiation therapy and proper diagnostics. The effect of ionizing radiation on cells and tissues depends on the radiation dose and energy level, but there is insufficient evidence concerning how tumor cells respond to the low and high doses of radiation that are often used in medical diagnostic and treatment modalities. The purpose of this study was to investigate radiation-induced gene expression changes in the MCF-7 breast adenocarcinoma cell line. Using microarray technology tools, we were able to screen the differential gene expressions profiles between various radiation doses applied to MCF-7 cells. Here, we report the substantial alteration in the expression level of genes after high-dose treatment. In contrast, no dramatic gene expression alterations were noticed after the application of low and medium doses of radiation. In response to a high radiation dose, MCF-7 cells exhibited down-regulation of biological pathways such as cell cycle, DNA replication, and DNA repair and activation of the p53 pathway. Similar dose-dependent responses were seen on the epigenetic level, which was tested by a microRNA expression analysis. MicroRNA analysis showed dose-dependent radiation-induced microRNA expression alterations that were associated with cell cycle arrest and cell death. An increased rate of apoptosis was determined by an Annexin V assay. The results of this study showed that high doses of radiation affect gene expression genetically and epigenetically, leading to alterations in cell cycle, DNA replication, and apoptosis. PMID:27226982

  12. ISFSI site boundary radiation dose rate analyses.

    PubMed

    Hagler, R J; Fero, A H

    2005-01-01

    Across the globe nuclear utilities are in the process of designing and analysing Independent Spent Fuel Storage Installations (ISFSI) for the purpose of above ground spent-fuel storage primarily to mitigate the filling of spent-fuel pools. Using a conjoining of discrete ordinates transport theory (DORT) and Monte Carlo (MCNP) techniques, an ISFSI was analysed to determine neutron and photon dose rates for a generic overpack, and ISFSI pad configuration and design at distances ranging from 1 to -1700 m from the ISFSI array. The calculated dose rates are used to address the requirements of 10CFR72.104, which provides limits to be enforced for the protection of the public by the NRC in regard to ISFSI facilities. For this overpack, dose rates decrease by three orders of magnitude through the first 200 m moving away from the ISFSI. In addition, the contributions from different source terms changes over distance. It can be observed that although side photons provide the majority of dose rate in this calculation, scattered photons and side neutrons take on more importance as the distance from the ISFSI is increased. PMID:16604670

  13. Monte Carlo modeling of the scatter radiation doses in IR

    NASA Astrophysics Data System (ADS)

    Mah, Eugene; He, Wenjun; Huda, Walter; Yao, Hai; Selby, Bayne

    2011-03-01

    Purpose: To use Monte Carlo techniques to compute the scatter radiation dose distribution patterns around patients undergoing Interventional Radiological (IR) examinations. Method: MCNP was used to model the scatter radiation air kerma (AK) per unit kerma area product (KAP) distribution around a 24 cm diameter water cylinder irradiated with monoenergetic x-rays. Normalized scatter fractions (SF) were generated defined as the air kerma at a point of interest that has been normalized by the Kerma Area Product incident on the phantom (i.e., AK/KAP). Three regions surrounding the water cylinder were investigated consisting of the area below the water cylinder (i.e., backscatter), above the water cylinder (i.e., forward scatter) and to the sides of the water cylinder (i.e., side scatter). Results: Immediately above and below the water cylinder and in the side scatter region, values of normalized SF decreased with the inverse square of the distance. For z-planes further away, the decrease was exponential. Values of normalized SF around the phantom were generally less than 10-4. Changes in normalized SF with x-ray energy were less than 20% and generally decreased with increasing x-ray energy. At a given distance from region where the x-ray beam enters the phantom, the normalized SF was higher in the backscatter regions, and smaller in the forward scatter regions. The ratio of forward to back scatter normalized SF was lowest at 60 keV and highest at 120 keV. Conclusion: Computed SF values quantify the normalized fractional radiation intensities at the operator location relative to the radiation intensities incident on the patient, where the normalization refers to the beam area that is incident on the patient. SF values can be used to estimate the radiation dose received by personnel within the procedure room, and which depend on the imaging geometry, patient size and location within the room. Monte Carlo techniques have the potential for simulating normalized SF values

  14. Gastrointestinal Dose-Histogram Effects in the Context of Dose-Volume–Constrained Prostate Radiation Therapy: Analysis of Data From the RADAR Prostate Radiation Therapy Trial

    SciTech Connect

    Ebert, Martin A.; Foo, Kerwyn; Haworth, Annette; Gulliford, Sarah L.; Kennedy, Angel; Joseph, David J.; Denham, James W.

    2015-03-01

    Purpose: To use a high-quality multicenter trial dataset to determine dose-volume effects for gastrointestinal (GI) toxicity following radiation therapy for prostate carcinoma. Influential dose-volume histogram regions were to be determined as functions of dose, anatomical location, toxicity, and clinical endpoint. Methods and Materials: Planning datasets for 754 participants in the TROG 03.04 RADAR trial were available, with Late Effects of Normal Tissues (LENT) Subjective, Objective, Management, and Analytic (SOMA) toxicity assessment to a median of 72 months. A rank sum method was used to define dose-volume cut-points as near-continuous functions of dose to 3 GI anatomical regions, together with a comprehensive assessment of significance. Univariate and multivariate ordinal regression was used to assess the importance of cut-points at each dose. Results: Dose ranges providing significant cut-points tended to be consistent with those showing significant univariate regression odds-ratios (representing the probability of a unitary increase in toxicity grade per percent relative volume). Ranges of significant cut-points for rectal bleeding validated previously published results. Separation of the lower GI anatomy into complete anorectum, rectum, and anal canal showed the impact of mid-low doses to the anal canal on urgency and tenesmus, completeness of evacuation and stool frequency, and mid-high doses to the anorectum on bleeding and stool frequency. Derived multivariate models emphasized the importance of the high-dose region of the anorectum and rectum for rectal bleeding and mid- to low-dose regions for diarrhea and urgency and tenesmus, and low-to-mid doses to the anal canal for stool frequency, diarrhea, evacuation, and bleeding. Conclusions: Results confirm anatomical dependence of specific GI toxicities. They provide an atlas summarizing dose-histogram effects and derived constraints as functions of anatomical region, dose, toxicity, and endpoint for

  15. Effective UV radiation dose in polyethylene exposed to weather

    NASA Astrophysics Data System (ADS)

    González-Mota, R.; Soto-Bernal, J. J.; Rosales-Candelas, I.; Calero Marín, S. P.; Vega-Durán, J. T.; Moreno-Virgen, R.

    2009-09-01

    In this work we quantified the effective UV radiation dose in orange and colorless polyethylene samples exposed to weather in the city of Aguascalientes, Ags. Mexico. The spectral distribution of solar radiation was calculated using SMART 2.9.5.; the samples absorption properties were measured using UV-Vis spectroscopy and the quantum yield was calculated using samples reflectance properties. The determining factor in the effective UV dose is the spectral distribution of solar radiation, although the chemical structure of materials is also important.

  16. Investigation of radiation doses in open space using TLD detectors.

    PubMed

    Reitz, G; Facius, R; Bilski, P; Olko, P

    2002-01-01

    The low energy component of the cosmic radiation field is strongly modified by the shielding of the spacecraft and it is time and location dependent. Thermoluminescent lithium fluoride detectors have been applied to determine the radiation doses inside the ESA-Facility BIOPAN. The BIOPAN facility was mounted outside and launched on a Foton spacecraft and opened to space to allow exposure of several experiments to open space. Standard TLD-600. TLD-700 chips, two layers MTS-Ns sintered pellets with different effective thickness of the sensitive layer and MTS-N of different thickness have been exposed with different shielding thicknesses in front of them. The measured TL signal in the 0.1 mm thick detector just shielded by an aluminised Kapton foil of 25 microm thickness in front yielded a dose of 29.8 Gy (calibrated with 137Cs gamma rays) for an exposure time of 12.7 days: after 2.5 g.cm(-2) shielding the doses dropped to 3 mGy. The monitoring of radiation doses and its depth dose distribution outside the spacecraft are of great interest for radiation protection of astronauts working in open space. The knowledge of depth-dose distribution is a prerequisite to determine the organ doses an astronaut will receive during an extravehicular activity (EVA). The BIOPAN experiments are to be continued in the future. PMID:12382937

  17. Errors and Uncertainties in Dose Reconstruction for Radiation Effects Research

    SciTech Connect

    Strom, Daniel J.

    2008-04-14

    Dose reconstruction for studies of the health effects of ionizing radiation have been carried out for many decades. Major studies have included Japanese bomb survivors, atomic veterans, downwinders of the Nevada Test Site and Hanford, underground uranium miners, and populations of nuclear workers. For such studies to be credible, significant effort must be put into applying the best science to reconstructing unbiased absorbed doses to tissues and organs as a function of time. In many cases, more and more sophisticated dose reconstruction methods have been developed as studies progressed. For the example of the Japanese bomb survivors, the dose surrogate “distance from the hypocenter” was replaced by slant range, and then by TD65 doses, DS86 doses, and more recently DS02 doses. Over the years, it has become increasingly clear that an equal level of effort must be expended on the quantitative assessment of uncertainty in such doses, and to reducing and managing uncertainty. In this context, this paper reviews difficulties in terminology, explores the nature of Berkson and classical uncertainties in dose reconstruction through examples, and proposes a path forward for Joint Coordinating Committee for Radiation Effects Research (JCCRER) Project 2.4 that requires a reasonably small level of effort for DOSES-2008.

  18. Cancer risks attributable to low doses of ionizing radiation: assessing what we really know.

    PubMed

    Brenner, David J; Doll, Richard; Goodhead, Dudley T; Hall, Eric J; Land, Charles E; Little, John B; Lubin, Jay H; Preston, Dale L; Preston, R Julian; Puskin, Jerome S; Ron, Elaine; Sachs, Rainer K; Samet, Jonathan M; Setlow, Richard B; Zaider, Marco

    2003-11-25

    High doses of ionizing radiation clearly produce deleterious consequences in humans, including, but not exclusively, cancer induction. At very low radiation doses the situation is much less clear, but the risks of low-dose radiation are of societal importance in relation to issues as varied as screening tests for cancer, the future of nuclear power, occupational radiation exposure, frequent-flyer risks, manned space exploration, and radiological terrorism. We review the difficulties involved in quantifying the risks of low-dose radiation and address two specific questions. First, what is the lowest dose of x- or gamma-radiation for which good evidence exists of increased cancer risks in humans? The epidemiological data suggest that it is approximately 10-50 mSv for an acute exposure and approximately 50-100 mSv for a protracted exposure. Second, what is the most appropriate way to extrapolate such cancer risk estimates to still lower doses? Given that it is supported by experimentally grounded, quantifiable, biophysical arguments, a linear extrapolation of cancer risks from intermediate to very low doses currently appears to be the most appropriate methodology. This linearity assumption is not necessarily the most conservative approach, and it is likely that it will result in an underestimate of some radiation-induced cancer risks and an overestimate of others. PMID:14610281

  19. Study of the effect of dose-rate on radiation-induced damage to human erythrocytes

    NASA Astrophysics Data System (ADS)

    Krokosz, Anita; Koziczak, Renata; Gonciarz, Marta; Szweda-Lewandowska, Zofia

    2006-01-01

    Human erythrocytes suspended in an isotonic Na-phosphate buffer, pH 7.4 (hematocrit of 2%) were irradiated with γ-rays at three dose-rates of 66.7, 36.7, 25 Gy min -1 in order to investigate the influence of the dose-rate on radiation-induced membrane damage, hemoglobin oxidation and loss of reduced glutathione. The obtained results showed that such processes as erythrocyte hemolysis, lipid and protein destruction depend on the radiation dose-rate. The parameter values describing these processes showed an inverse dose-rate effect.

  20. KREAM: Korean Radiation Exposure Assessment Model for Aviation Route Dose

    NASA Astrophysics Data System (ADS)

    Hwang, J.; Dokgo, K.; Choi, E. J.; Kim, K. C.; Kim, H. P.; Cho, K. S. F.

    2014-12-01

    Since Korean Air has begun to use the polar route from Seoul/ICN airport to New York/JFK airport on August 2006, there are explosive needs for the estimation and prediction against cosmic radiation exposure for Korean aircrew and passengers in South Korea from public. To keep pace with those needs of public, Korean government made the law on safety standards and managements of cosmic radiation for the flight attendants and the pilots in 2013. And we have begun to develop our own Korean Radiation Exposure Assessment Model (KREAM) for aviation route dose since last year funded by Korea Meteorological Administration (KMA). GEANT4 model and NRLMSIS 00 model are used for calculation of the energetic particles' transport in the atmosphere and for obtaining the background atmospheric neutral densities depending on altitude. For prediction the radiation exposure in many routes depending on the various space weather effects, we constructed a database from pre-arranged simulations using all possible combinations of R, S, and G, which are the space weather effect scales provided by the National Oceanic and Atmospheric Administration (NOAA). To get the solar energetic particles' spectrum at the 100 km altitude which we set as a top of the atmospheric layers in the KREAM, we use ACE and GOES satellites' proton flux observations. We compare the results between KREAM and the other cosmic radiation estimation programs such as CARI-6M which is provided by the Federal Aviation Agency (FAA). We also validate KREAM's results by comparison with the measurement from Liulin-6K LET spectrometer onboard Korean commercial flights and Korean Air Force reconnaissance flights.

  1. Overview of ICRP Committee 2: doses from radiation exposure.

    PubMed

    Harrison, J D; Paquet, F

    2016-06-01

    The focus of the work of Committee 2 of the International Commission on Radiological Protection (ICRP) is the computation of dose coefficients compliant with Publication 103 A set of reference computational phantoms is being developed, based on medical imaging data, and used for radiation transport calculations. Biokinetic models used to describe the behaviour of radionuclides in body tissues are being updated, also leading to changes in organ doses and effective dose coefficients. Dose coefficients for external radiation exposure of adults calculated using the new reference phantoms were issued as Publication 116, jointly with the International Commission on Radiation Units and Measurements. Forthcoming reports will provide internal dose coefficients for radionuclide inhalation and ingestion by workers, and associated bioassay data. Work is in progress to revise internal dose coefficients for members of the public, and, for the first time, to provide reference values for external exposures of the public. Committee 2 is also working with Committee 3 on dose coefficients for radiopharmaceuticals, and leading a cross-Committee initiative to give advice on the use of effective dose. PMID:26984902

  2. RADIATION DOSE IN PAEDIATRIC COMPUTED TOMOGRAPHY: RISKS AND BENEFITS

    PubMed Central

    Ogbole, G.I.

    2010-01-01

    Computed tomography (CT) is a powerful tool for the accurate and effective diagnosis and treatment of a variety of conditions because it allows high-resolution three-dimensional images to be acquired very quickly. However as the number of CT procedures performed globally have continued to increase; with growing concerns about patient protection. Currently, no system is in place to track patient doses and the lifetime cumulative dose from medical sources. The widespread use of CT even in developing countries has raised questions regarding the possible threat to public health especially in children. The best available risk estimates suggest that paediatric CT will result in significantly increased lifetime radiation risk over adult CT. Studies have shown that lower milliampere-second (mAs) settings can be used for children without significant loss of information. Although the risk–benefit balance is still strongly tilted toward benefit, there is still need for caution. Furthermore since the frequency of paediatric CT examinations is rapidly increasing, and estimates suggest that quantitative lifetime radiation risks for children are not negligible, efforts should be made toward more active reduction of CT exposure settings in paediatric patients. This article hopes to address this concerns and draw attention to the fact that children are not ‘small adults ’ and should therefore be treated differently. PMID:25161479

  3. Linking Doses with Clinical Scores of Hematopoietic Acute Radiation Syndrome.

    PubMed

    Hu, Shaowen

    2016-10-01

    In radiation accidents, determining the radiation dose the victim received is a key step for medical decision making and patient prognosis. To reconstruct and evaluate the absorbed dose, researchers have developed many physical devices and biological techniques during the last decades. However, using the physical parameter "absorbed dose" alone is not sufficient to predict the clinical development of the various organs injured in an individual patient. In operational situations for radiation accidents, medical responders need more urgently to classify the severity of the radiation injury based on the signs and symptoms of the patient. In this work, the author uses a unified hematopoietic model to describe dose-dependent dynamics of granulocytes, lymphocytes, and platelets, and the corresponding clinical grading of hematopoietic acute radiation syndrome. This approach not only visualizes the time course of the patient's probable outcome in the form of graphs but also indirectly gives information of the remaining stem and progenitor cells, which are responsible for the autologous recovery of the hematopoietic system. Because critical information on the patient's clinical evolution can be provided within a short time after exposure and only peripheral cell counts are required for the simulation, these modeling tools will be useful to assess radiation exposure and injury in human-involved radiation accident/incident scenarios. PMID:27575346

  4. Time-dependent radiation dose simulations during interplanetary space flights

    NASA Astrophysics Data System (ADS)

    Dobynde, Mikhail; Shprits, Yuri; Drozdov, Alexander; Hoffman, Jeffrey; Li, Ju

    2016-07-01

    Space radiation is one of the main concerns in planning long-term interplanetary human space missions. There are two main types of hazardous radiation - Solar Energetic Particles (SEP) and Galactic Cosmic Rays (GCR). Their intensities and evolution depend on the solar activity. GCR activity is most enhanced during solar minimum, while the most intense SEPs usually occur during the solar maximum. SEPs are better shielded with thick shields, while GCR dose is less behind think shields. Time and thickness dependences of the intensity of these two components encourage looking for a time window of flight, when radiation intensity and dose of SEP and GCR would be minimized. In this study we combine state-of-the-art space environment models with GEANT4 simulations to determine the optimal shielding, geometry of the spacecraft, and launch time with respect to the phase of the solar cycle. The radiation environment was described by the time-dependent GCR model, and the SEP spectra that were measured during the period from 1990 to 2010. We included gamma rays, electrons, neutrons and 27 fully ionized elements from hydrogen to nickel. We calculated the astronaut's radiation doses during interplanetary flights using the Monte-Carlo code that accounts for the primary and the secondary radiation. We also performed sensitivity simulations for the assumed spacecraft size and thickness to find an optimal shielding. In conclusion, we present the dependences of the radiation dose as a function of launch date from 1990 to 2010, for flight durations of up to 3 years.

  5. Equivalent dose and effective dose from stray radiation during passively scattered proton radiotherapy for prostate cancer

    NASA Astrophysics Data System (ADS)

    Fontenot, Jonas; Taddei, Phillip; Zheng, Yuanshui; Mirkovic, Dragan; Jordan, Thomas; Newhauser, Wayne

    2008-03-01

    Proton therapy reduces the integral therapeutic dose required for local control in prostate patients compared to intensity-modulated radiotherapy. One proposed benefit of this reduction is an associated decrease in the incidence of radiogenic secondary cancers. However, patients are also exposed to stray radiation during the course of treatment. The purpose of this study was to quantify the stray radiation dose received by patients during proton therapy for prostate cancer. Using a Monte Carlo model of a proton therapy nozzle and a computerized anthropomorphic phantom, we determined that the effective dose from stray radiation per therapeutic dose (E/D) for a typical prostate patient was approximately 5.5 mSv Gy-1. Sensitivity analysis revealed that E/D varied by ±30% over the interval of treatment parameter values used for proton therapy of the prostate. Equivalent doses per therapeutic dose (HT/D) in specific organs at risk were found to decrease with distance from the isocenter, with a maximum of 12 mSv Gy-1 in the organ closest to the treatment volume (bladder) and 1.9 mSv Gy-1 in the furthest (esophagus). Neutrons created in the nozzle predominated effective dose, though neutrons created in the patient contributed substantially to the equivalent dose in organs near the proton field. Photons contributed less than 15% to equivalent doses.

  6. Radiation dose reconstruction for epidemiologic uses. Final report

    SciTech Connect

    1995-05-12

    The report presents specific and practical recommendations for whether, when, and how dose-reconstruction studies should be conducted, with an emphasis on public participation. The book provides an overview of the basic requirements and technical aspects of dose reconstruction; presents lessons to be learned from dose reconstructions after Chernobyl, Three Mile Island, and elsewhere; explores the potential benefits and limitations of using current available biological markers; discusses how to establish the source term determining what was released; explores methods for identifying the environmental pathways by which radiation reaches the body; offers details on three major categories of dose assessment; and examines priority-setting and strengths and limitations of epidemiological studies.

  7. Use of EORTC Target Definition Guidelines for Dose-Intensified Salvage Radiation Therapy for Recurrent Prostate Cancer: Results of the Quality Assurance Program of the Randomized Trial SAKK 09/10

    SciTech Connect

    Sassowsky, Manfred; Gut, Philipp; Hölscher, Tobias; Hildebrandt, Guido; Müller, Arndt-Christian; Najafi, Yousef; Kohler, Götz; Kranzbühler, Helmut; Guckenberger, Matthias; Zwahlen, Daniel R.; Azinwi, Ngwa C.; Plasswilm, Ludwig; Takacs, Istvan; Reuter, Christiane; Sumila, Marcin; Manser, Peter; Ost, Piet; Böhmer, Dirk; Pilop, Christiane; Aebersold, Daniel M.; and others

    2013-11-01

    Purpose: Different international target volume delineation guidelines exist and different treatment techniques are available for salvage radiation therapy (RT) for recurrent prostate cancer, but less is known regarding their respective applicability in clinical practice. Methods and Materials: A randomized phase III trial testing 64 Gy vs 70 Gy salvage RT was accompanied by an intense quality assurance program including a site-specific and study-specific questionnaire and a dummy run (DR). Target volume delineation was performed according to the European Organisation for the Research and Treatment of Cancer guidelines, and a DR-based treatment plan was established for 70 Gy. Major and minor protocol deviations were noted, interobserver agreement of delineated target contours was assessed, and dose-volume histogram (DVH) parameters of different treatment techniques were compared. Results: Thirty European centers participated, 43% of which were using 3-dimensional conformal RT (3D-CRT), with the remaining centers using intensity modulated RT (IMRT) or volumetric modulated arc technique (VMAT). The first submitted version of the DR contained major deviations in 21 of 30 (70%) centers, mostly caused by inappropriately defined or lack of prostate bed (PB). All but 5 centers completed the DR successfully with their second submitted version. The interobserver agreement of the PB was moderate and was improved by the DR review, as indicated by an increased κ value (0.59 vs 0.55), mean sensitivity (0.64 vs 0.58), volume of total agreement (3.9 vs 3.3 cm{sup 3}), and decrease in the union volume (79.3 vs 84.2 cm{sup 3}). Rectal and bladder wall DVH parameters of IMRT and VMAT vs 3D-CRT plans were not significantly different. Conclusions: The interobserver agreement of PB delineation was moderate but was improved by the DR. Major deviations could be identified for the majority of centers. The DR has improved the acquaintance of the participating centers with the trial

  8. Estimation of organ dose equivalents from residents of radiation-contaminated buildings with Rando phantom measurements.

    PubMed

    Lee, J S; Dong, S L; Wu, T H

    1999-05-01

    Since August 1996, a dose reconstruction model has been conducted with thermoluminescent dosimeter (TLD)-embedded chains, belts and badges for external dose measurements on the residents in radiation-contaminated buildings. The TLD dosimeters, worn on the front of the torso, would not be adequate for dose measurement in cases when the radiation is anisotropic or the incident angles of radiation sources are not directed in the front-to-back direction. The shielding and attenuation by the body would result in the dose equivalent estimation being somewhat skewed. An organ dose estimation method with a Rando phantom under various exposure geometries is proposed. The conversion factors, obtained from the phantom study, may be applicable to organ dose estimations for residents in the contaminated buildings if the incident angles correspond to the phantom simulation results. There is a great demand for developing a mathematical model or Monte Carlo calculation to deal with complicated indoor layout geometry problems involving ionizing radiation. Further research should be directed toward conducting laboratory simulation by investigating the relationship between doses delivered from multiple radiation sources. It is also necessary to collaborate with experimental biological dosimetry, such as chromosome aberration analysis, fluorescence in situ hybridization (FISH) and retrospective ESR-dosimetry with teeth, applied to the residents, so that the organ dose equivalent estimations may be more reliable for radio-epidemiological studies. PMID:10214706

  9. Evaluation of radiation dose to anthropomorphic paediatric models from positron-emitting labelled tracers

    NASA Astrophysics Data System (ADS)

    Xie, Tianwu; Zaidi, Habib

    2014-03-01

    PET uses specific molecules labelled with positron-emitting radionuclides to provide valuable biochemical and physiological information. However, the administration of radiotracers to patients exposes them to low-dose ionizing radiation, which is a concern in the paediatric population since children are at a higher cancer risk from radiation exposure than adults. Therefore, radiation dosimety calculations for commonly used positron-emitting radiotracers in the paediatric population are highly desired. We evaluate the absorbed dose and effective dose for 19 positron-emitting labelled radiotracers in anthropomorphic paediatric models including the newborn, 1-, 5-, 10- and 15-year-old male and female. This is achieved using pre-calculated S-values of positron-emitting radionuclides of UF-NCI paediatric phantoms and published biokinetic data for various radiotracers. The influence of the type of anthropomorphic model, tissue weight factors and direct human- versus mouse-derived biokinetic data on the effective dose for paediatric phantoms was also evaluated. In the case of 18F-FDG, dosimetry calculations of reference paediatric patients from various dose regimens were also calculated. Among the considered radiotracers, 18F-FBPA and 15O-water resulted in the highest and lowest effective dose in the paediatric phantoms, respectively. The ICRP 103 updated tissue-weighting factors decrease the effective dose in most cases. Substantial differences of radiation dose were observed between direct human- versus mouse-derived biokinetic data. Moreover, the effect of using voxel- versus MIRD-type models on the calculation of the effective dose was also studied. The generated database of absorbed organ dose and effective dose for various positron-emitting labelled radiotracers using new generation computational models and the new ICRP tissue-weighting factors can be used for the assessment of radiation risks to paediatric patients in clinical practice. This work also contributes

  10. Low radiation doses; are they harmful in infancy?

    PubMed

    Asteriadis, Ioannis

    2004-01-01

    Adults usually ask their physician about the kind of treatment they will be given and especially whether ionizing radiation applied for therapeutic purposes is harmful. When these treatments are applied to children and especially to infants of <18 months of age, parents should be more reluctant to give their consent for such a treatment. A paper under the title "Effect of low doses of ionizing radiation in infancy on cognitive function in adulthood: Swedish population based cohort study" written by Hall P, Adami HO, Trichopoulos D, et al. and published in the British Journal of Medicine 2004, 328:19-21 presents new and important data referring to 3094 males who at an age of <18 months had undergone radiation treatment for haemangiomas of the head and other dermatological lesions. The doses they received in their brain were from 20 mGy to > 250 mGy. Findings were exciting. 17%-32% of these infants did not attend highschool lessons. Many failed to pass tests related to cognitive tests for learning ability or logical reasoning. On the contrary spatial recognition was intact. As the authors state it is important to know that a cranial tomography examination administers to the brain of infants about 120 mGy. These doses are relevant to the doses tested above and found harmful. More radiation protection studies about the possible harmful effects on humans who receive doses of radiation for diagnostic and/or therapeutic purposes, are necessary. PMID:16868634

  11. Potential dose distributions at proposed surface radioactvity clearance levels resulting from occupational scenarios.

    SciTech Connect

    Kamboj, S.; Yu, C.; Rabovsky, J.

    2011-08-02

    The purpose of this report is to evaluate the potential dose distribution resulting from surface radioactivity, using occupational radiation exposure scenarios. The surface radioactivity clearance values considered in this analysis may ultimately replace those currently specified in the U.S. Department of Energy (DOE) requirements and guidance for radiological protection of workers, the public and the environment. The surface contamination values apply to radioactive contamination deposited on a surface (i.e., not incorporated into the interior of the material). For these calculations, the dose coefficients for intake of radionuclides were taken from ICRP Publication 68 (ICRP 1994), and external exposure dose coefficients were taken from the compact disc (CD) that accompanied Federal Guidance Report (FGR) 13 (Eckerman et al. 1999). The ICRP Publication 68 dose coefficients were based on ICRP Publication 60 (ICRP 1990) and were used specifically for worker dose calculations. The calculated dose in this analysis is the 'effective dose' (ED), rather than the 'effective dose equivalent' (EDE).

  12. Radiation-induced lung damage: dose-time-fractionation considerations.

    PubMed

    Van Dyk, J; Mah, K; Keane, T J

    1989-01-01

    The comparison of different dose-time-fractionation schedules requires the use of an isoeffect formula. In recent years, the NSD isoeffect formula has been heavily criticized. In this report, we consider an isoeffect formula which is specifically developed for radiation-induced lung damage. The formula is based on the linear-quadratic model and includes a factor for overall treatment time. The proposed procedures allow for the simultaneous derivation of an alpha/beta ratio and a gamma/beta time factor. From animal data in the literature, the derived alpha/beta and gamma/beta ratios for acute lung damage are 5.0 +/- 1.0 Gy and 2.7 +/- 1.4 Gy2/day respectively, while for late damage the suggested values are 2.0 Gy and 0.0 Gy2/day. Data from two clinical studies, one prospective and the other retrospective, were also analysed and corresponding alpha/beta and gamma/beta ratios were determined. For the prospective clinical study, with a limited range of doses per fraction, the resultant alpha/beta and gamma/beta ratios were 0.9 +/- 2.6 Gy and 2.6 +/- 2.5 Gy2/day. The combination of the retrospective and prospective data yielded alpha/beta and gamma/beta ratios of 3.3 +/- 1.5 Gy and 2.4 +/- 1.5 Gy2/day, respectively. One potential advantage of this isoeffect formalism is that it might possibly be applied to both acute and late lung damage. The results of this formulation for acute lung damage indicate that time-dependent effects such as slow repair or proliferation might be more important in determining isoeffect doses than previously predicted by the estimated single dose (ED) formula. Although we present this as an alternative approach, we would caution against its clinical use until its applicability has been confirmed by additional clinical data. PMID:2928557

  13. Fewer doses of HPV vaccine result in immune response similar to three-dose regimen

    Cancer.gov

    NCI scientists report that two doses of a human papillomavirus (HPV) vaccine, trademarked as Cervarix, resulted in similar serum antibody levels against two of the most carcinogenic types of HPV (16 and 18), compared to a standard three dose regimen.

  14. Radiation Dose Testing on Juno High Voltage Cables

    NASA Technical Reports Server (NTRS)

    Green, Nelson W.; Kirkham, Harold; Kim, Wousik; McAlpine, Bill

    2008-01-01

    The Juno mission to Jupiter will have a highly elliptical orbit taking the spacecraft through the radiation belts surrounding the planet. During these passes through the radiation belts, the spacecraft will be subject to high doses of radiation from energetic electrons and protons with energies ranging from 10 keV to 1 GeV. While shielding within the spacecraft main body will reduce the total absorbed dose to much of the spacecraft electronics, instruments and cables on the outside of the spacecraft will receive much higher levels of absorbed dose. In order to estimate the amount of degradation to two such cables, testing has been performed on two coaxial cables intended to provide high voltages to three of the instruments on Juno. Both cables were placed in a vacuum of 5x10(exp -6) torr and cooled to -50(deg)C prior to exposure to the radiation sources. Measurements of the coaxial capacitance per unit length and partial discharge noise floor indicate that increasing levels of radiation make measurable but acceptably small changes to the F EP Teflon utilized in the construction of these cables. In addition to the radiation dose testing, observations were made on the internal electrostatic charging characteristics of these cables and multiple discharges were recorded.

  15. Radiation Dose Testing on Juno High Voltage Cables

    NASA Technical Reports Server (NTRS)

    Green, Nelson W.; Kirkham, Harold; Kim, Wousik; McAlpine, Bill

    2008-01-01

    The Juno mission to Jupiter will have a highly elliptical orbit taking the spacecraft through the radiation belts surrounding the planet. During these passes through the radiation belts, the spacecraft will be subject to high doses of radiation from energetic electrons and protons with energies ranging from 10 keV to 1 GeV. While shielding within the spacecraft main body will reduce the total absorbed dose to much of the spacecraft electronics, instruments and cables on the outside of the spacecraft will receive much higher levels of absorbed dose. In order to estimate the amount of degradation to two such cables, testing has been performed on two coaxial cables intended to provide high voltages to three of the instruments on Juno. Both cables were placed in a vacuum of 5x10-6 torr and cooled to -50 C prior to exposure to the radiation sources. Measurements of the coaxial capacitance per unit length and partial discharge noise floor indicate that increasing levels of radiation make measurable but acceptably small changes to the F EP Teflon utilized in the construction of these cables. In addition to the radiation dose testing, observations were made on the internal electrostatic charging characteristics of these cables and multiple discharges were recorded.

  16. Metaphase chromosome aberrations as markers of radiation exposure and dose

    SciTech Connect

    Brooks, A.L.; Khan, M.A.; Jostes, R.F.; Cross, F.T.

    1992-10-01

    Chromosome aberration frequency provides the most reliable biological marker of dose for detecting acute accidental radiation exposure. Significant radiation-induced changes in the frequency of chromosome aberrations can be detected at very low doses. Our paper provides information on using molecular chromosome probes ``paints`` to score chromosome damage and illustrates how technical advances make it possible to understand mechanisms involved during formation of chromosome aberrations. In animal studies chromosome aberrations provide a method to relate cellular damage to cellular dose. Using an In vivo/In vitro approach aberrations provided a biological marker of dose from radon progeny exposure which was used to convert WLM to dose in rat tracheal epithelial cells. Injection of Chinese hamsters with {sup 144}Ce which produced a low dose rate exposure of bone marrow to either low-LET radiation increased the sensitivity of the cells to subsequent external exposure to {sup 60}Co. These studies demonstrated the usefulness of chromosome damage as a biological marker of dose and cellular responsiveness.

  17. Metaphase chromosome aberrations as markers of radiation exposure and dose

    SciTech Connect

    Brooks, A.L.; Khan, M.A.; Jostes, R.F.; Cross, F.T.

    1992-10-01

    Chromosome aberration frequency provides the most reliable biological marker of dose for detecting acute accidental radiation exposure. Significant radiation-induced changes in the frequency of chromosome aberrations can be detected at very low doses. Our paper provides information on using molecular chromosome probes paints'' to score chromosome damage and illustrates how technical advances make it possible to understand mechanisms involved during formation of chromosome aberrations. In animal studies chromosome aberrations provide a method to relate cellular damage to cellular dose. Using an In vivo/In vitro approach aberrations provided a biological marker of dose from radon progeny exposure which was used to convert WLM to dose in rat tracheal epithelial cells. Injection of Chinese hamsters with [sup 144]Ce which produced a low dose rate exposure of bone marrow to either low-LET radiation increased the sensitivity of the cells to subsequent external exposure to [sup 60]Co. These studies demonstrated the usefulness of chromosome damage as a biological marker of dose and cellular responsiveness.

  18. Impact of the Fukushima nuclear accident on background radiation doses measured by control dosimeters in Japan.

    PubMed

    Romanyukha, Alexander; King, David L; Kennemur, Lisa K

    2012-05-01

    After the 9.0 magnitude earthquake and subsequent massive tsunami on 11 March 2011 in Japan, several reactors at the Fukushima Daiichi Nuclear Power Plant suffered severe damage. There was immediate participation of U.S. Navy vessels and other United States Department of Defense (DoD) teams that were already in the area at the time of the disaster or arrived shortly thereafter. The correct determination of occupational dose equivalent requires estimation of the background dose component measured by control dosimeters, which is subsequently subtracted from the total dose equivalent measured by personal dosimeters. The purpose of the control dosimeters is to determine the amount of radiation dose equivalent that has accumulated on the dosimeter from background or other non-occupational sources while they are in transit or being stored. Given the release of radioactive material and potential exposure to radiation from the Fukushima Daiichi Nuclear Power Plant and the process by which the U.S. Navy calculates occupational exposure to ionizing radiation, analysis of pre- and post-event control dosimeters is warranted. Several hundred historical dose records from the Naval Dosimetry Center (NDC) database were analyzed and compared with the post-accident dose equivalent data of control dosimeters. As result, it was shown that the dose contribution of the radiation and released radiological materials from the Fukushima nuclear accident to background radiation doses is less than 0.375 μSv d for shallow and deep photon dose equivalent. There is no measurable effect on neutron background exposure. The latter has at least two important conclusions. First, the NDC can use doses measured by control dosimeters at issuing sites in Japan for determination of personnel dose equivalents; second, the dose data from control dosimeters prior to and after the Fukushima accident may be used to assist in dose reconstruction of non-radiological (non-badged) personnel at these locations

  19. Measurements of individual radiation doses in residents living around the Fukushima Nuclear Power Plant.

    PubMed

    Nagataki, Shigenobu; Takamura, Noboru; Kamiya, Kenji; Akashi, Makoto

    2013-11-01

    effects. In particular, the schedule of decontamination needs reconsideration. The decontamination map is determined based on the results of airborne monitoring and the radiation dose calculated from readings taken at the monitoring posts at the initial period of the accident. The decontamination protocol should be reevaluated based on the individual doses of the people who desire to live in those areas. PMID:24131040

  20. REDUCING STRAY RADIATION DOSE FOR A PEDIATRIC PATIENT RECEIVING PROTON CRANIOSPINAL IRRADIATION.

    PubMed

    Taddei, Phillip J; Mirkovic, Dragan; Fontenot, Jonas D; Giebeler, Annelise; Zheng, Yuanshui; Titt, Uwe; Woo, Shiao; Newhauser, Wayne D

    2009-10-01

    The aim of this study was to quantify stray radiation dose from neutrons emanating from a proton treatment unit and to evaluate methods of reducing this dose for a pediatric patient undergoing craniospinal irradiation. The organ equivalent doses and effective dose from stray radiation were estimated for a 30.6-Gy treatment using Monte Carlo simulations of a passive scattering treatment unit and a patient-specific voxelized anatomy. The treatment plan was based on computed tomography images of a 10-yr-old male patient. The contribution to stray radiation was evaluated for the standard nozzle and for the same nozzle but with modest modifications to suppress stray radiation. The modifications included enhancing the local shielding between the patient and the primary external neutron source and increasing the distance between them. The effective dose from stray radiation emanating from the standard nozzle was 322 mSv; enhancements to the nozzle reduced the effective dose by as much as 43%. These results add to the body of evidence that modest enhancements to the treatment unit can reduce substantially the effective dose from stray radiation. PMID:20865143

  1. Implications of Intercellular Signaling for Radiation Therapy: A Theoretical Dose-Planning Study

    SciTech Connect

    McMahon, Stephen J.; McGarry, Conor K.; Butterworth, Karl T.; O'Sullivan, Joe M.; Hounsell, Alan R.; Prise, Kevin M.

    2013-12-01

    Purpose: Recent in vitro results have shown significant contributions to cell killing from signaling effects at doses that are typically used in radiation therapy. This study investigates whether these in vitro observations can be reconciled with in vivo knowledge and how signaling may have an impact on future developments in radiation therapy. Methods and Materials: Prostate cancer treatment plans were generated for a series of 10 patients using 3-dimensional conformal therapy, intensity modulated radiation therapy (IMRT), and volumetric modulated arc therapy techniques. These plans were evaluated using mathematical models of survival following modulated radiation exposures that were developed from in vitro observations and incorporate the effects of intercellular signaling. The impact on dose–volume histograms and mean doses were evaluated by converting these survival levels into “signaling-adjusted doses” for comparison. Results: Inclusion of intercellular communication leads to significant differences between the signalling-adjusted and physical doses across a large volume. Organs in low-dose regions near target volumes see the largest increases, with mean signaling-adjusted bladder doses increasing from 23 to 33 Gy in IMRT plans. By contrast, in high-dose regions, there is a small decrease in signaling-adjusted dose due to reduced contributions from neighboring cells, with planning target volume mean doses falling from 74 to 71 Gy in IMRT. Overall, however, the dose distributions remain broadly similar, and comparisons between the treatment modalities are largely unchanged whether physical or signaling-adjusted dose is compared. Conclusions: Although incorporating cellular signaling significantly affects cell killing in low-dose regions and suggests a different interpretation for many phenomena, their effect in high-dose regions for typical planning techniques is comparatively small. This indicates that the significant signaling effects observed in vitro

  2. Average radiation doses in a standard head examination for 250 CT systems

    SciTech Connect

    McCrohan, J.L.; Patterson, J.F.; Gagne, R.M.; Goldstein, H.A.

    1987-04-01

    Approximately 250 computed tomography (CT) systems were surveyed in a nationwide study to determine the average radiation dose resulting from a typical adult head procedure. The multiple scan average dose (MSAD) was selected as the dose descriptor. For the typical adult CT head procedure, the MSAD was generally within 2.2-6.8 rads (22-68 mGy). Variations in dose by a factor of two or more were often seen for a given manufacturer and model. These dose ranges indicate a potential to reduce dose by carefully selecting imaging techniques. Overall, variations in dose can result from differences in the user's choice of technique (desired image quality) or from actual differences in scanner performance (caused by differences in collimation, filtration, or geometry). To use CT appropriately, a facility should consider dose as well as image quality in selecting optimal techniques for typical modes of operation.

  3. Effect of radiation protraction on BED in the case of large fraction dose

    SciTech Connect

    Kuperman, V. Y.

    2013-08-15

    Purpose: To investigate the effect of radiation protraction on biologically effective dose (BED) in the case when dose per fraction is significantly greater than the standard dose of 2 Gy.Methods: By using the modified linear-quadratic model with monoexponential repair, the authors investigate the effect of long treatment times combined with dose escalation.Results: The dependences of the protraction factor and the corresponding BED on fraction time were determined for different doses per fraction typical for stereotactic radiosurgery (SRS) and stereotactic body radiation therapy (SBRT). In the calculations, the authors consider changes in the BED to the normal tissue under the condition of fixed BED to the target.Conclusion: The obtained results demonstrate that simultaneous increase in fraction time and dose per fraction can be beneficial for SRS and SBRT because of the related decrease in BED to normal structures while BED to the target is fixed.

  4. Radiation dose to personnel during percutaneous renal calculus removal

    SciTech Connect

    Bush, W.H.; Jones, D.; Brannen, G.E.

    1985-12-01

    Radiation dose to the radiologist and other personnel was measured during 102 procedures for percutaneous removal of renal calculi from the upper collecting system. A mobile C-arm image intensifier was used to guide entrance to the kidney and stone removal. Average fluoroscopy time was 25 min. Exposure to personnel was monitored by quartz-fiber dosimeters at the collar level above the lead apron. Average radiation dose to the radiologist was 10 mrem (0.10 mSv) per case; to the surgical nurse, 4 mrem (0.04 mSv) per case; to the radiologic technologist, 4 mrem (0.04 mSv) per case; and to the anesthesiologist, 3 mrem (0.03 mSv) per case. Radiation dose to the uroradiologic team during percutaneous nephrostolithotomy is similar to that from other interventional fluoroscopic procedures and is within acceptable limits for both physicians and assisting personnel.

  5. Review of standards for limitation of radiation dose to radiation workers and members of the public

    SciTech Connect

    Kocher, D.C.

    1992-01-01

    Topics covered in the review include: current radiation protection standards for workers; current radiation protection standards for the routine exposures of the public; environmental radiation standards for specific practices or sources; protective action guides for accidental releases of radioactivity to the environment; de minimis dose, exempt levels of radioactivity, and below regulatory concern.

  6. Review of standards for limitation of radiation dose to radiation workers and members of the public

    SciTech Connect

    Kocher, D.C.

    1992-07-01

    Topics covered in the review include: current radiation protection standards for workers; current radiation protection standards for the routine exposures of the public; environmental radiation standards for specific practices or sources; protective action guides for accidental releases of radioactivity to the environment; de minimis dose, exempt levels of radioactivity, and below regulatory concern.

  7. Comparison of radiation dose exposure in patients undergoing percutaneous coronary intervention vs. peripheral intervention

    PubMed Central

    Bartus, Stanislaw; Rakowski, Tomasz; Bobrowska, Beata; Rutka, Joanna; Zabowka, Anna; Tokarek, Tomasz; Dudek, Dariusz; Dubiel, Jacek

    2014-01-01

    Introduction Most endovascular techniques are associated with patient and personal exposure to radiation during the procedure. Ionising radiation can cause deterministic effects, such as skin injury, as well as stochastic effects, which increase the long-term risk of malignancy. Endovascular operators need to be aware of radiation danger and take all necessary steps to minimise the risk to patients and staff. Some procedures, especially percutaneous peripheral artery revascularisation, are associated with increased radiation dose due to time-consuming operations. There is limited data comparing radiation dose during percutaneous coronary intervention (PCI) with percutaneous transluminal angioplasty (PTA) of peripheral arteries. Aim To compare the radiation dose in percutaneous coronary vs. peripheral interventions in one centre with a uniform system of protection methods. Material and methods A total of 352 patients were included in the study. This included 217 patients undergoing PCI (single and multiple stenting) and 135 patients undergoing PTA (in lower extremities, carotid artery, renal artery, and subclavian artery). Radiation dose, fluoroscopy time, and total procedural time were reviewed. Cumulative radiation dose was measured in gray (Gy) units. Results The total procedural time was significantly higher in PTA (PCI vs. PTA: 60 (45–85) min vs. 75 (50–100) min), p < 0.001. The radiation dose for PCI procedures was significantly higher in comparison to PTA (PCI vs. PTA: 1.36 (0.83–2.23) Gy vs. 0.27 (0.13–0.46) Gy), p < 0.001. There was no significant difference in the fluoroscopy time (PCI vs. PTA: 12.9 (8.2–21.5) min vs. 14.4 (8.0–22.6) min), p = 0.6. The analysis of correlation between radiation dose and fluoroscopy time in PCI and PTA interventions separately shows a strong correlation in PCI group (r = 0.785). However, a weak correlation was found in PTA group (r = 0.317). Conclusions The radiation dose was significantly higher during PCI in

  8. Proton tissue dose for the blood forming organ in human geometry: Isotropic radiation

    NASA Technical Reports Server (NTRS)

    Khandelwal, G. S.; Wilson, J. W.

    1974-01-01

    A computer program is described which calculates doses averaged within five major segments of the blood forming organ in the human body taking into account selfshielding of the detailed body geometry and nuclear star effects for proton radiation of arbitrary energy spectrum (energy less than 1 GeV) and isotropic angular distribution. The dose calculation includes the first term of an asymptotic series expansion of transport theory which is known to converge rapidly for most points in the human body. The result is always a conservative estimate of dose and is given as physical dose (rad) and dose equivalent (rem).

  9. Methods of space radiation dose analysis with applications to manned space systems

    NASA Technical Reports Server (NTRS)

    Langley, R. W.; Billings, M. P.

    1972-01-01

    The full potential of state-of-the-art space radiation dose analysis for manned missions has not been exploited. Point doses have been overemphasized, and the critical dose to the bone marrow has been only crudely approximated, despite the existence of detailed man models and computer codes for dose integration in complex geometries. The method presented makes it practical to account for the geometrical detail of the astronaut as well as the vehicle. Discussed are the major assumptions involved and the concept of applying the results of detailed proton dose analysis to the real-time interpretation of on-board dosimetric measurements.

  10. Assessment of radiation doses downwind of the Nevada Test Site

    SciTech Connect

    Anspaugh, L.R.; Church, B.W.

    1983-11-01

    The Department of Energy's Off-Site Radiation Exposure Review Project has the goal of reconstructing both individual and population doses via all pathways including the ingestion and inhalation of radionuclides. As this is a reconstruction and not a prediction for safety purposes, the desired output is the best estimate of radiation dose with an appropriate expression of uncertainty. For the 80 events of interest, the data consistently available are external ..gamma.. exposure-rate measurements, measurements of airborne gross ..beta.. activity, and measurements of fission yield and of activation products created in the device environment. For most organs, the external ..gamma.. dose is much greater than the dose from ingestion which, in turn, is much greater than the dose from inhalation. The gastrointestinal tract may receive as large a dose from ingestion as from external exposure, depending upon dietary habits. The dose to the thyroid gland is usually dominated by ingestion and the dose from inhalation can be nearly as large as that from external exposure. Several example calculations are presented for specific individuals.