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Sample records for nagasaki dosimetry system

  1. Initial radiation dosimetry at Hiroshima and Nagasaki

    SciTech Connect

    Loewe, W.E.

    1983-09-01

    The dosimetry of A-bomb survivors at Hiroshima and Nagasaki is discussed in light of the new dosimetry developed in 1980 by the author. The important changes resulting from the new dosimetry are the ratios of neutron to gamma doses, particularly at Hiroshima. The implications of these changes in terms of epidemiology and radiation protection standards are discussed. (ACR)

  2. Radiation-related posterior lenticular opacities in Hiroshima and Nagasaki atomic bomb survivors based on the DS86 dosimetry system

    SciTech Connect

    Otake, M.; Schull, W.J. )

    1990-01-01

    This paper investigates the quantitative relationship of ionizing radiation to the occurrence of posterior lenticular opacities among the survivors of the atomic bombings of Hiroshima and Nagasaki suggested by the DS86 dosimetry system. DS86 doses are available for 1983 (93.4%) of the 2124 atomic bomb survivors analyzed in 1982. The DS86 kerma neutron component for Hiroshima survivors is much smaller than its comparable T65DR component, but still 4.2-fold higher (0.38 Gy at 6 Gy) than that in Nagasaki (0.09 Gy at 6 Gy). Thus, if the eye is especially sensitive to neutrons, there may yet be some useful information on their effects, particularly in Hiroshima. The dose-response relationship has been evaluated as a function of the separately estimated gamma-ray and neutron doses. Among several different dose-response models without and with two thresholds, we have selected as the best model the one with the smallest x2 or the largest log likelihood value associated with the goodness of fit. The best fit is a linear gamma-linear neutron relationship which assumes different thresholds for the two types of radiation. Both gamma and neutron regression coefficients for the best fitting model are positive and highly significant for the estimated DS86 eye organ dose.

  3. The new radiation dosimetry for the A-bombs in Hiroshima and Nagasaki

    SciTech Connect

    Kerr, G.D.

    1988-08-18

    Extensive work has been conducted over the past few years to reassess all aspects of the radiation dosimetry for the A-bombs in Hiroshima and Nagasaki. This work has included reviews of the bomb yields, source terms, air transport of neutrons and gamma rays, neutron-induced radioactivity and thermoluminescence in exposed materials, shielding of individuals by buildings, and calculations of organ doses. The results of these theoretical and experimental activities have led to the development of a new dosimetry system which is designated as the Dosimetry System 1986 (DS86). New DS86 estimates of tissue kerma in air and absorbed dose to fifteen organs are available for 94,787 survivors who were either outside and unshielded, outside and shielded by houses, or inside and shielded by houses (64,408 in Hiroshima and 30,379 in Nagasaki). The organ doses are calculated on an age-dependent basis as follows: infants (less than 3 years old at the time of bombing, ATB), children (3 to 12 years old ATB), and adults (more than 12 years old ATB). Work in progress includes the extension of the DS86 system to Nagasaki survivors who were shielded either by terrain or by factory buildings.

  4. Intercomparison study on (152)Eu gamma ray and (36)Cl AMS measurements for development of the new Hiroshima-Nagasaki Atomic Bomb Dosimetry System 2002 (DS02).

    PubMed

    Hoshi, M; Endo, S; Tanaka, K; Ishikawa, M; Straume, T; Komura, K; Rühm, W; Nolte, E; Huber, T; Nagashima, Y; Seki, R; Sasa, K; Sueki, K; Fukushima, H; Egbert, S D; Imanaka, T

    2008-07-01

    In the process of developing a new dosimetry system for atomic bomb survivors in Hiroshima and Nagasaki (DS02), an intercomparison study between (152)Eu and (36)Cl measurements was proposed, to reconcile the discrepancy previously observed in the Hiroshima data between measurements and calculations of thermal neutron activation products. Nine granite samples, exposed to the atomic-bomb radiation in Hiroshima within 1,200 m of the hypocenter, as well as mixed standard solutions containing known amounts of europium and chlorine that were neutron-activated by a (252)Cf source, were used for the intercomparison. Gamma-ray spectrometry for (152)Eu was carried out with ultra low-background Ge detectors at the Ogoya Underground Laboratory, Kanazawa University, while three laboratories participated in the (36)Cl measurement using accelerator mass spectrometry (AMS): The Technical University of Munich, Germany, the Lawrence Livermore National Laboratory, USA and the University of Tsukuba, Japan. Measured values for the mixed standard solutions showed good agreement among the participant laboratories. They also agreed well with activation calculations, using the neutron fluences monitored during the (252)Cf irradiation, and the corresponding activation cross-sections taken from the JENDL-3.3 library. The measured-to-calculated ratios obtained were 1.02 for (152)Eu and 0.91-1.02 for (36)Cl, respectively. Similarly, the results of the granite intercomparison indicated good agreement with the DS02 calculation for these samples. An average measured-to-calculated ratio of 0.98 was obtained for all granite intercomparison measurements. The so-called neutron discrepancy that was previously observed and that which included increasing measured-to-calculated ratios for thermal neutron activation products for increasing distances beyond 1,000 m from the hypocenter was not seen in the results of the intercomparison study. The previously claimed discrepancy could be explained by

  5. Workshop Report on Atomic Bomb Dosimetry--Review of Dose Related Factors for the Evaluation of Exposures to Residual Radiation at Hiroshima and Nagasaki.

    PubMed

    Kerr, George D; Egbert, Stephen D; Al-Nabulsi, Isaf; Bailiff, Ian K; Beck, Harold L; Belukha, Irina G; Cockayne, John E; Cullings, Harry M; Eckerman, Keith F; Granovskaya, Evgeniya; Grant, Eric J; Hoshi, Masaharu; Kaul, Dean C; Kryuchkov, Victor; Mannis, Daniel; Ohtaki, Megu; Otani, Keiko; Shinkarev, Sergey; Simon, Steven L; Spriggs, Gregory D; Stepanenko, Valeriy F; Stricklin, Daniela; Weiss, Joseph F; Weitz, Ronald L; Woda, Clemens; Worthington, Patricia R; Yamamoto, Keiko; Young, Robert W

    2015-12-01

    Groups of Japanese and American scientists, supported by international collaborators, have worked for many years to ensure the accuracy of the radiation dosimetry used in studies of health effects in the Japanese atomic bomb survivors. Reliable dosimetric models and systems are especially critical to epidemiologic studies of this population because of their importance in the development of worldwide radiation protection standards. While dosimetry systems, such as Dosimetry System 1986 (DS86) and Dosimetry System 2002 (DS02), have improved, the research groups that developed them were unable to propose or confirm an additional contribution by residual radiation to the survivor's total body dose. In recognition of the need for an up-to-date review of residual radiation exposures in Hiroshima and Nagasaki, a half-day technical session was held for reports on newer studies at the 59 th Annual HPS Meeting in 2014 in Baltimore, MD. A day-and-a-half workshop was also held to provide time for detailed discussion of the newer studies and to evaluate their potential use in clarifying the residual radiation exposure to atomic bomb survivors at Hiroshima and Nagasaki. The process also involved a re-examination of very early surveys of radioisotope emissions from ground surfaces at Hiroshima and Nagasaki and early reports of health effects. New insights were reported on the potential contribution to residual radiation from neutron-activated radionuclides in the airburst's dust stem and pedestal and in unlofted soil, as well as from fission products and weapon debris from the nuclear cloud. However, disparate views remain concerning the actual residual radiation doses received by the atomic bomb survivors at different distances from the hypocenter. The workshop discussion indicated that measurements made using thermal luminescence and optically stimulated luminescence, like earlier measurements, especially in very thin layers of the samples, could be expanded to detect possible

  6. Feasibility of the Pharmacy DOTS System in Nagasaki Prefecture.

    PubMed

    Hamada, Yukari; Nakao, Rieko; Ohnishi, Mayumi

    2016-01-01

    Objective This study aimed to investigate the preparedness of pharmacies to provide DOTS in Nagasaki Prefecture, Japan, and to analyze the feasibility of this system with a view toward providing a basis for future administrative studies to consider its adoption.Methods A self-administered mail questionnaire survey was conducted, involving the owners (mostly pharmacists) of 533 pharmacies belonging to designated medical institutions for tuberculosis treatment in Nagasaki Prefecture, seeking information on the following: 1) respondent attributes, 2) pharmacy-related information, 3) experience of participating in tuberculosis-related academic meetings, 4) recognition of DOTS and desire to cooperate with the pharmacy DOTS system and participate in related workshops, and 5) challenges and requirements of the provision of DOTS at pharmacies. Responses were analyzed using the chi-square test, focusing on factors related to the respondents' desire to cooperate with the pharmacy DOTS system and participate in related workshops. The significance level was set at P<0.05.Results On analyzing 212 valid responses (valid response rate: 39.8%), "participating in academic meetings or related workshops", "supporting patients with tuberculosis", "recognizing DOTS", "recognizing the pharmacy DOTS system", "calculating additional medical fees for standard dispensing", and "establishing community liaison systems" were significantly correlated with "wishing to cooperate with the pharmacy DOTS system". Furthermore, age under 50, in addition to "participating in academic meetings or related workshops", "supporting patients with tuberculosis", "recognizing DOTS", "recognizing the pharmacy DOTS system", "calculating additional medical fees for standard dispensing", and "establishing community liaison systems" were significantly correlated with "wishing to participate in related workshops". More than 60% and 50% of the respondents mentioned "tuberculosis-related knowledge and

  7. Long-term epidemiological studies of atomic bomb survivors in Hiroshima and Nagasaki: study populations, dosimetry and summary of health effects.

    PubMed

    Okubo, Toshiteru

    2012-10-01

    The Radiation Effects Research Foundation succeeded 28 years' worth of activities of the Atomic Bomb Casualty Commission on long-term epidemiological studies in Hiroshima and Nagasaki. It has three major cohorts of atomic bomb survivors, i.e. the Life Span Study (LSS) of 120,000 people, the In Utero Cohort of 3600 and the Second Generation Study (F(1)) of 77,000. The LSS and F(1) studies include a periodic health examination for each sub-cohort, i.e. the Adult Health Study and the F(1) Clinical Study, respectively. An extensive individual dose estimation was conducted and the system was published as the Dosimetry System established in 2002 (DS02). As results of these studies, increases of cancers in relation to dose were clearly shown. Increases of other mortality causes were also observed, including heart and respiratory diseases. There has been no evidence of genetic effects in the survivors' children, including cancer and other multi-factorial diseases. The increase in the expected mortality number in the next 10 y would allow the analyses of further details of the observed effects related to atomic bomb exposures. PMID:22908354

  8. Choice of model and uncertainties of the gamma-ray and neutron dosimetry in relation to the chromosome aberrations data in Hiroshima and Nagasaki.

    PubMed

    Rühm, W; Walsh, L; Chomentowski, M

    2003-07-01

    Chromosome data pertaining to blood samples from 1,703 survivors of the Hiroshima and Nagasaki A-bombs, were utilized and different models for chromosome aberration dose response investigated. Models applied included those linear or linear-quadratic in equivalent dose. Models in which neutron and gamma doses were treated separately (LQ-L model) were also used, which included either the use of a low-dose limiting value for the relative biological effectiveness (RBE) of neutrons of R(0)=70+/-10 or an RBE value of R(1)=15+/-5 at 1 Gy. The use of R(1) incorporates the assumption that it is much better known than R(0), with much less associated uncertainty. In addition, error-reducing transformations were included which were found to result in a 50% reduction of the standard error associated with one of the model fit parameters which is associated with the proportion of cells with at least one aberration, at 1 Gy gamma dose. Several justifiable modifications to the DS86 doses according to recent nuclear retrospective dosimetry measurements were also investigated. Gamma-dose modifications were based on published thermoluminescence measurements of quartz samples from Hiroshima and on a tentative reduction for Nagasaki factory worker candidates by a factor of 0.6. Neutron doses in Hiroshima were modified to become consistent with recent fast neutron activation data based on copper samples. The applied dose modifications result in an increase in non-linearity of the dose-response curve for Hiroshima, and a corresponding decrease in that for Nagasaki, an effect found to be most pronounced for the LQ-L models investigated. As a result the difference in the dose-response curves observed for both cities based on DS86 doses, is somewhat reduced but cannot be entirely explained by the dose modifications applied. The extent to which the neutrons contribute to chromosome aberration induction in Hiroshima depends significantly on the model used. The LQ-L model including an R(1

  9. Chemical dosimetry system for criticality accidents.

    PubMed

    Miljanić, Saveta; Ilijas, Boris

    2004-01-01

    Ruder Bosković Institute (RBI) criticality dosimetry system consists of a chemical dosimetry system for measuring the total (neutron + gamma) dose, and a thermoluminescent (TL) dosimetry system for a separate determination of the gamma ray component. The use of the chemical dosemeter solution chlorobenzene-ethanol-trimethylpentane (CET) is based on the radiolytic formation of hydrochloric acid, which protonates a pH indicator, thymolsulphonphthalein. The high molar absorptivity of its red form at 552 nm is responsible for a high sensitivity of the system: doses in the range 0.2-15 Gy can be measured. The dosemeter has been designed as a glass ampoule filled with the CET solution and inserted into a pen-shaped plastic holder. For dose determinations, a newly constructed optoelectronic reader has been used. The RBI team took part in the International Intercomparison of Criticality Accident Dosimetry Systems at the SILENE Reactor, Valduc, June 2002, with the CET dosimetry system. For gamma ray dose determination TLD-700 TL detectors were used. The results obtained with CET dosemeter show very good agreement with the reference values. PMID:15353694

  10. Development of A-bomb survivor dosimetry

    SciTech Connect

    Kerr, G.D.

    1995-12-31

    An all important datum in risk assessment is the radiation dose to individual survivors of the bombings in Hiroshima and Nagasaki. The first set of dose estimates for survivors was based on a dosimetry system developed in 1957 by the Oak Ridge National Laboratory (ORNL). These Tentative 1957 Doses (T57D) were later replaced by a more extensive and refined set of Tentative 1965 Doses (T65D). The T65D system of dose estimation for survivors was also developed at ORNL and served as a basis for risk assessment throughout the 1970s. In the late 1970s, it was suggested that there were serious inadequacies with the T65D system, and these inadequacies were the topic of discussion at two symposia held in 1981. In early 1983, joint US- Japan research programs were established to conduct a thorough review of all aspects of the radiation dosimetry for the Hiroshima and Nagasaki A-bomb survivors. A number of important contributions to this review were made by ORNL staff members. The review was completed in 1986 and a new Dosimetry System 1986 (DS86) was adopted for use. This paper discusses the development of the various systems of A-bomb survivor dosimetry, and the status of the current DS86 system as it is being applied in the medical follow-up studies of the A-bomb survivors and their offspring.

  11. EPID dosimetry for pretreatment quality assurance with two commercial systems.

    PubMed

    Bailey, Daniel W; Kumaraswamy, Lalith; Bakhtiari, Mohammad; Malhotra, Harish K; Podgorsak, Matthew B

    2012-01-01

    This study compares the EPID dosimetry algorithms of two commercial systems for pretreatment QA, and analyzes dosimetric measurements made with each system alongside the results obtained with a standard diode array. 126 IMRT fields are examined with both EPID dosimetry systems (EPIDose by Sun Nuclear Corporation, Melbourne FL, and Portal Dosimetry by Varian Medical Systems, Palo Alto CA) and the diode array, MapCHECK (also by Sun Nuclear Corporation). Twenty-six VMAT arcs of varying modulation complexity are examined with the EPIDose and MapCHECK systems. Optimization and commissioning testing of the EPIDose physics model is detailed. Each EPID IMRT QA system is tested for sensitivity to critical TPS beam model errors. Absolute dose gamma evaluation (3%, 3 mm, 10% threshold, global normalization to the maximum measured dose) yields similar results (within 1%-2%) for all three dosimetry modalities, except in the case of off-axis breast tangents. For these off-axis fields, the Portal Dosimetry system does not adequately model EPID response, though a previously-published correction algorithm improves performance. Both MapCHECK and EPIDose are found to yield good results for VMAT QA, though limitations are discussed. Both the Portal Dosimetry and EPIDose algorithms, though distinctly different, yield similar results for the majority of clinical IMRT cases, in close agreement with a standard diode array. Portal dose image prediction may overlook errors in beam modeling beyond the calculation of the actual fluence, while MapCHECK and EPIDose include verification of the dose calculation algorithm, albeit in simplified phantom conditions (and with limited data density in the case of the MapCHECK detector). Unlike the commercial Portal Dosimetry package, the EPIDose algorithm (when sufficiently optimized) allows accurate analysis of EPID response for off-axis, asymmetric fields, and for orthogonal VMAT QA. Other forms of QA are necessary to supplement the limitations of the

  12. A crack model of the Hiroshima atomic bomb: explanation of the contradiction of "Dosimetry system 1986".

    PubMed

    Hoshi, M; Endo, S; Takada, J; Ishikawa, M; Nitta, Y; Iwatani, K; Oka, T; Fujita, S; Shizuma, K; Hasai, H

    1999-12-01

    There has been a large discrepancy between the Dosimetry system 1986 (DS86) and measured data, some of which data in Hiroshima at about 1.5 km ground distance from the hypocenter are about 10 times larger than the calculation. Therefore its causes have long been discussed, since it will change the estimated radiation risks obtained based on the Hiroshima and Nagasaki data. In this study the contradiction was explained by a bare-fission-neutron leakage model through a crack formed at the time of neutron emission. According to the present calculation, the crack has a 3 cm parallel spacing, which is symmetric with respect to the polar axis from the hypocenter to the epicenter of the atomic bomb. We made also an asymmetric opening closing 3/4 of this symmetric geometry, because there are some data which shows asymmetry. In addition, the height of the neutron emission point was elevated 90 m. By using the asymmetric calculation, especially for long distant data located more than 1 km, it was verified that all of the activity data induced by thermal and fast neutrons, were simultaneously explained within the data scattering. The neutron kerma at a typical 1.5 km ground distance increases 3 and 8 times more than DS86 based on the symmetric and asymmetric model, respectively. PMID:10805003

  13. High-energy gamma rays in Hiroshima and Nagasaki: Implications for risk and W{sub R}

    SciTech Connect

    Straume, T.

    1995-12-01

    Based on the DS86 dosimetry system, nearly all of the dose to survivors of the atomic bombings of Hiroshima and Nagasaki was due to unusually high-energy gamma rays, predominantly in the 2- to 5-MeV range. These high energies resulted in part from neutron capture gamma rays as the bomb neutrons penetrated large distances of air. Because of the inverse relationship between energy and biological effectiveness, these high-energy gamma rays are expected to be substantially less effective in producing biological damage than the radiations commonly used in radiobiology and risk assessment. This observation has implications for radiation protection and risk assessment.

  14. Dosimetry quality assurance in Martin Marietta Energy Systems` centralized external dosimetry system

    SciTech Connect

    Souleyrette, M.L.

    1992-10-23

    External dosimetry needs at the four Martin Marietta Energy Systems facilities are served by Energy Systems Centralized External Dosimetry System (CEDS). The CEDS is a four plant program with four dosimeter distribution centers and two dosimeter processing centers. Each plant has its own distribution center, while processing centers are located at ORNL and the Y-12 Plant. The program has been granted accreditation by the Department of Energy Laboratory Accreditation Program (DOELAP). The CEDS is a TLD based system which is responsible for whole-body beta-gamma, neutron, and extremity monitoring. Beta-gamma monitoring is performed using the Harshaw/Solon Technologies model 8805 dosimeter. Effective October 1, 1992 the standard silver mylar has been replaced with an Avery mylar foil blackened on the underside with ink. This was done in an effort to reduce the number of light induced suspect readings. At this time we have little operational experience with the new blackened mylars-The CEDS neutron dosimeter is the Harshaw model 8806B. This card/holder configuration contains two TLD-600/TLD-700 chip pairs; one pair is located beneath a cadmium filter and one pair is located beneath a plastic filter. In routine personnel monitoring the CEDS neutron dosimeter is always paired with a CEDS beta-gamma dosimeter.The CEDS extremity dosimeter is composed of a Harshaw thin TLD-700 dosiclip placed inside a Teledyne RB-4 finger sachet. The finger sachet provides approximately 7 mg/cm{sup 2} filtration over the chip. A teflon ring surrounds the dosiclip to help prevent tearing of the vinyl sachet.

  15. Dosimetry quality assurance in Martin Marietta Energy Systems' centralized external dosimetry system

    SciTech Connect

    Souleyrette, M.L.

    1992-10-23

    External dosimetry needs at the four Martin Marietta Energy Systems facilities are served by Energy Systems Centralized External Dosimetry System (CEDS). The CEDS is a four plant program with four dosimeter distribution centers and two dosimeter processing centers. Each plant has its own distribution center, while processing centers are located at ORNL and the Y-12 Plant. The program has been granted accreditation by the Department of Energy Laboratory Accreditation Program (DOELAP). The CEDS is a TLD based system which is responsible for whole-body beta-gamma, neutron, and extremity monitoring. Beta-gamma monitoring is performed using the Harshaw/Solon Technologies model 8805 dosimeter. Effective October 1, 1992 the standard silver mylar has been replaced with an Avery mylar foil blackened on the underside with ink. This was done in an effort to reduce the number of light induced suspect readings. At this time we have little operational experience with the new blackened mylars-The CEDS neutron dosimeter is the Harshaw model 8806B. This card/holder configuration contains two TLD-600/TLD-700 chip pairs; one pair is located beneath a cadmium filter and one pair is located beneath a plastic filter. In routine personnel monitoring the CEDS neutron dosimeter is always paired with a CEDS beta-gamma dosimeter.The CEDS extremity dosimeter is composed of a Harshaw thin TLD-700 dosiclip placed inside a Teledyne RB-4 finger sachet. The finger sachet provides approximately 7 mg/cm[sup 2] filtration over the chip. A teflon ring surrounds the dosiclip to help prevent tearing of the vinyl sachet.

  16. A thermoluminescence dosimetry system for personal monitoring in Ireland.

    PubMed

    Currivan, L; Spain, D; Donnelly, H; Colgan, P A

    2001-01-01

    In 1993 the decision was taken to replace film badges with thermoluminescence dosemeters (TLDs) as the main form of dosemeter for both whole-body and extremity monitoring at the Dosimetry Service of the Radiological Protection Institute of Ireland (RPII) in Dublin. A review of commercially available automatic TLD systems was carried out to identify the system which best met the RPII's requirements. This paper describes the dosimetry system used, and, in addition, discusses the problems encountered and how these were addressed. PMID:11586731

  17. Internal Dosimetry Code System Using Biokinetics Models

    Energy Science and Technology Software Center (ESTSC)

    2003-11-12

    Version 00 InDose is an internal dosimetry code to calculate dose estimations using biokinetic models (presented in ICRP-56 to ICRP71) as well as older ones. The code uses the ICRP-66 respiratory tract model and the ICRP-30 gastrointestinal tract model as well as the new and old biokinetic models. The code was written in such a way that the user can change any parameters of any one of the models without recompiling the code. All parametersmore » are given in well annotated parameters files that the user may change. As default, these files contain the values listed in ICRP publications. The full InDose code was planned to have three parts: 1) the main part includes the uptake and systemic models and is used to calculate the activities in the body tissues and excretion as a function of time for a given intake. 2) An optimization module for automatic estimation of the intake for a specific exposure case. 3) A module to calculate the dose due to the estimated intake. Currently, the code is able to perform only it`s main task (part 1) while the other two have to be done externally using other tools. In the future, developers would like to add these modules in order to provide a complete solution. The code was tested extensively to verify accuracy of its results. The verification procedure was divided into three parts: 1) verification of the implementation of each model, 2) verification of the integrity of the whole code, and 3) usability test. The first two parts consisted of comparing results obtained with InDose to published results for the same cases. For example ICRP-78 monitoring data. The last part consisted of participating in the 3rd EIE-IDA and assessing some of the scenarios provided in this exercise. These tests where presented in a few publications. Good agreement was found between the results of InDose and published data.« less

  18. IMRT verification using a radiochromic/optical-CT dosimetry system

    NASA Astrophysics Data System (ADS)

    Oldham, Mark; Guo, Pengyi; Gluckman, Gary; Adamovics, John

    2006-12-01

    This work represents our first experiences relating to IMRT verification using a relatively new 3D dosimetry system consisting of a PRESAGETM dosimeter (Heuris Inc, Pharma LLC) and an optical-CT scanning system (OCTOPUSTM TM MGS Inc). This work builds in a step-wise manner on prior work in our lab.

  19. Gamma-ray exposure from neutron-induced radionuclides in soil in Hiroshima and Nagasaki based on DS02 calculations.

    PubMed

    Imanaka, Tetsuji; Endo, Satoru; Tanaka, Kenichi; Shizuma, Kiyoshi

    2008-07-01

    As a result of joint efforts by Japanese, US and German scientists, the Dosimetry System 2002 (DS02) was developed as a new dosimetry system, to evaluate individual radiation dose to atomic bomb survivors in Hiroshima and Nagasaki. Although the atomic bomb radiation consisted of initial radiation and residual radiation, only initial radiation was reevaluated in DS02 because, for most survivors in the life span study group, the residual dose was negligible compared to the initial dose. It was reported, however, that there were individuals who entered the city at the early stage after the explosion and experienced hemorrhage, diarrhea, etc., which were symptoms of acute radiation syndrome. In this study, external exposure due to radionuclides induced in soil by atomic bomb neutrons was reevaluated based on DS02 calculations, as a function of both the distance from the hypocenters and the elapsed time after the explosions. As a result, exposure rates of 6 and 4 Gy h(-1) were estimated at the hypocenter at 1 min after the explosion in Hiroshima and Nagasaki, respectively. These exposure rates decreased rapidly by a factor of 1,000 1 day later, and by a factor of 1 million 1 week later. Maximum cumulative exposure from the time of explosion was 1.2 and 0.6 Gy at the hypocenters in Hiroshima and Nagasaki, respectively. Induced radiation decreased also with distance from the hypocenters, by a factor of about 10 at 500 m and a factor of three to four hundreds at 1,000 m. Consequently, a significant exposure due to induced radiation is considered feasible to those who entered the area closer to a distance of 1,000 m from the hypocenters, within one week after the bombing. PMID:18368418

  20. The dosimetry system DS86 and the neutron discrepancy in Hiroshima--historical review, present status, and future options.

    PubMed

    Rühm, W; Kellerer, A M; Korschinek, G; Faestermann, T; Knie, K; Rugel, G; Kato, K; Nolte, E

    1998-12-01

    The historical development of the dosimetry systems for Hiroshima and Nagasaki is outlined from the time immediately after the A-bomb explosions to the publication of the dosimetry system DS86 in 1987, and the present status of the so-called Hiroshima neutron discrepancy is summarized. Several long-lived radionuclides are discussed with regard to their production by neutrons from the A-bomb explosions. With the exception of 63Ni, these radionuclides have not, up to now, been measured in samples from Hiroshima and Nagasaki. Two of them, 63Ni in copper samples and 39Ar in granite samples, were predominantly produced by fast neutrons. 63Ni can be determined by accelerator mass spectrometry with a gas-filled analyzing magnet. It should be measurable, in the near future, in copper samples up to 1500 m from the hypocenter in Hiroshima. 39Ar can be measured in terms of low-level beta-counting. This should be feasible up to a distance of about 1000 m from the hypocenter. Three radionuclides, 10Be, 14C, and 59Ni, were produced predominantly by thermal neutrons with smaller fractions due to the epithermal and fast neutrons, which contribute increasingly more at larger distances from the hypocenter. State-of-the-art accelerator mass spectrometry is likely to permit the determination of 10Be close to the hypocenter and of 14C up to a distance of about 1000 m. 59Ni should be detectable up to a distance of about 1000 m in terms of accelerator mass spectrometry with a gas-filled magnet. The measurements of 10Be, 14C, 39Ar, 59Ni -- and potentially of 131Xe -- can be performed in the same granitic sample that was already analyzed for 36Cl, 41Ca, 6Co, 152Eu, and 154Eu. This will provide extensive information on the neutron spectrum at the specified location, and similarly complete analyses can conceivably be performed on granite samples at other locations. PMID:10052679

  1. Neutrons confirmed in Nagasaki and at the Army Pulsed Radiation Facility: implications for Hiroshima.

    PubMed

    Straume, T; Harris, L J; Marchetti, A A; Egbert, S D

    1994-05-01

    Recent reports have clearly demonstrated that large discrepancies exist between neutron activation measured in Hiroshima and activation calculated using the current dosimetry system, DS86. The reports confirmed previous results for cobalt activation in Hiroshima that suggested problems, and this has spurred a joint U.S.-Japan effort to identify the source(s) of this discrepancy. Here, new results are presented that appear to eliminate both the measurements of neutron activation and the DS86 air-transport calculations as potential sources of the discrepancy in Hiroshima. Computer transport of DS86 fission neutrons through large distances of air was validated using concrete samples from Nagasaki and chloride detectors placed at selected distances from a bare uranium reactor. In both cases, accelerator mass spectrometry was used to measure thermal neutron activation via the reaction, 35Cl(n, gamma)36Cl (half-life, 301,000 years). Good agreement was observed between measurements of neutron activation and DS86 calculations for Nagasaki, as well as for the reactor experiment. Thus the large discrepancy observed in Hiroshima appears not to be due to uncertainties in air-transport calculations or in the activation measurements; rather, the discrepancy appears to be due to uncertainties associated with the Hiroshima bomb itself. PMID:8183989

  2. Advanced dosimetry systems for the space transport and space station

    NASA Technical Reports Server (NTRS)

    Wailly, L. F.; Schneider, M. F.; Clark, B. C.

    1972-01-01

    Advanced dosimetry system concepts are described that will provide automated and instantaneous measurement of dose and particle spectra. Systems are proposed for measuring dose rate from cosmic radiation background to greater than 3600 rads/hr. Charged particle spectrometers, both internal and external to the spacecraft, are described for determining mixed field energy spectra and particle fluxes for both real time onboard and ground-based computer evaluation of the radiation hazard. Automated passive dosimetry systems consisting of thermoluminescent dosimeters and activation techniques are proposed for recording the dose levels for twelve or more crew members. This system will allow automatic onboard readout and data storage of the accumulated dose and can be transmitted to ground after readout or data records recovered with each crew rotation.

  3. EPID based in vivo dosimetry system: clinical experience and results.

    PubMed

    Celi, Sofia; Costa, Emilie; Wessels, Claas; Mazal, Alejandro; Fourquet, Alain; Francois, Pascal

    2016-01-01

    Mandatory in several countries, in vivo dosimetry has been recognized as one of the next milestones in radiation oncology. Our department has implemented clinically an EPID based in vivo dosimetry system, EPIgray, by DOSISOFT S.A., since 2006. An analysis of the measurements per linac and energy over a two-year period was performed, which included a more detailed examination per technique and treat-ment site over a six-month period. A comparison of the treatment planning system doses and the doses estimated by EPIgray shows a mean of the differences of 1.9% (± 5.2%) for the two-year period. The 3D conformal treatment plans had a mean dose difference of 2.0% (± 4.9%), while for intensity-modulated radiotherapy and volumetric-modulated arc therapy treatments the mean dose difference was -3.0 (± 5.3%) and -2.5 (± 5.2%), respectively. In addition, root cause analyses were conducted on the in vivo dosimetry measurements of two breast cancer treatment techniques, as well as prostate treatments with intensity-modulated radiotherapy and volumetric-modulated arc therapy. During the breast study, the dose differences of breast treatments in supine position were correlated to patient setup and EPID positioning errors. Based on these observations, an automatic image shift correc-tion algorithm is developed by DOSIsoft S.A. The prostate study revealed that beams and arcs with out-of-tolerance in vivo dosimetry results tend to have more complex modulation and a lower exposure of the points of interest. The statistical studies indicate that in vivo dosimetry with EPIgray has been successfully imple-mented for classical and complex techniques in clinical routine at our institution. The additional breast and prostate studies exhibit the prospects of EPIgray as an easy supplementary quality assurance tool. The validation, the automatization, and the reduction of false-positive results represent an important step toward adaptive radiotherapy with EPIgray. PMID:27167283

  4. UNCERTAINTY ANALYSIS FOR THE TECHA RIVER DOSIMETRY SYSTEM

    SciTech Connect

    Napier, Bruce A.; Degteva, M. O.; Shagina, N. B.; Anspaugh, L. R.

    2013-04-01

    Uncertainties in the doses estimated for the members of the Techa River Cohort (TRC) are being estimated with a two-dimensional Monte Carlo approach. In order to provide more accurate and precise estimates of individual dose (and thus more precise estimates of radiation risk) for the members of the TRC, a new dosimetric calculation system, the Techa River Dosimetry System-2009 (TRDS-2009) has been prepared. The deterministic version of the improved dosimetry system TRDS-2009D was basically completed in April 2009. Recent developments in evaluation of dose-response models in light of uncertain dose have highlighted the importance of different types of uncertainties in the development of individual dose estimates. These include uncertain parameters that may be either shared (common to some or all individuals) or unshared (a unique value for each person whose dose is to be estimated) within the dosimetric cohort. The nature of the type of uncertainty may be aleatory (random variability of true values due to stochastic processes) or epistemic (due to lack of complete knowledge about a unique quantity). Finally, there is a need to identify whether the structure of the errors is either related to measurement (the estimate differs from the true value by an error that is stochastically independent of the true value; frequently called classical uncertainty) or related to grouping (the true value varies from the estimate by an error that is random and is independent of the estimate; frequently called Berkson uncertainty). An approach has been developed that identifies the nature of the various input parameters and calculational methods incorporated in the Techa River Dosimetry System (based on the TRDS-2009D implementation), and a stochastic calculation model has been prepared to estimate the uncertainties in the dose estimates. This article reviews the concepts of uncertainty analysis, the equations, and input parameters, and then identifies the authors’ interpretations

  5. GENII (Generation II): The Hanford Environmental Radiation Dosimetry Software System: Volume 3, Code maintenance manual: Hanford Environmental Dosimetry Upgrade Project

    SciTech Connect

    Napier, B.A.; Peloquin, R.A.; Strenge, D.L.; Ramsdell, J.V.

    1988-09-01

    The Hanford Environmental Dosimetry Upgrade Project was undertaken to incorporate the internal dosimetry models recommended by the International Commission on Radiological Protection (ICRP) in updated versions of the environmental pathway analysis models used at Hanford. The resulting second generation of Hanford environmental dosimetry computer codes is compiled in the Hanford Environmental Dosimetry System (Generation II, or GENII). This coupled system of computer codes is intended for analysis of environmental contamination resulting from acute or chronic releases to, or initial contamination of, air, water, or soil, on through the calculation of radiation doses to individuals or populations. GENII is described in three volumes of documentation. This volume is a Code Maintenance Manual for the serious user, including code logic diagrams, global dictionary, worksheets to assist with hand calculations, and listings of the code and its associated data libraries. The first volume describes the theoretical considerations of the system. The second volume is a Users' Manual, providing code structure, users' instructions, required system configurations, and QA-related topics. 7 figs., 5 tabs.

  6. GENII: The Hanford Environmental Radiation Dosimetry Software System: Volume 2, Users' manual: Hanford Environmental Dosimetry Upgrade Project

    SciTech Connect

    Napier, B.A.; Peloquin, R.A.; Strenge, D.L.; Ramsdell, J.V.

    1988-11-01

    The Hanford Environmental Dosimetry Upgrade Project was undertaken to incorporate the internal dosimetry models recommended by the International Commission on Radiological Protection (ICRP) in updated versions of the environmental pathway analysis models used at Hanford. The resulting second generation of Hanford environmental dosimetry computer codes is compiled in the Hanford Environmental Dosimetry System (Generation II, or GENII). The purpose of this coupled system of computer codes is to analyze environmental contamination of, air, water, or soil. This is accomplished by calculating radiation doses to individuals or populations. GENII is described in three volumes of documentation. This second volume is a Users' Manual, providing code structure, users' instructions, required system configurations, and QA-related topics. The first volume describes the theoretical considerations of the system. The third volume is a Code Maintenance Manual for the user who requires knowledge of code detail. It includes logic diagrams, global dictionary, worksheets, example hand calculations, and listings of the code and its associated data libraries. 27 refs., 17 figs., 23 tabs.

  7. Dosimetry audit of radiotherapy treatment planning systems.

    PubMed

    Bulski, Wojciech; Chełmiński, Krzysztof; Rostkowska, Joanna

    2015-07-01

    In radiotherapy Treatment Planning Systems (TPS) various calculation algorithms are used. The accuracy of dose calculations has to be verified. Numerous phantom types, detectors and measurement methodologies are proposed to verify the TPS calculations with dosimetric measurements. A heterogeneous slab phantom has been designed within a Coordinated Research Project (CRP) of the IAEA. The heterogeneous phantom was developed in the frame of the IAEA CRP. The phantom consists of frame slabs made with polystyrene and exchangeable inhomogeneity slabs equivalent to bone or lung tissue. Special inserts allow to position thermoluminescent dosimeters (TLD) capsules within the polystyrene slabs below the bone or lung equivalent slabs and also within the lung equivalent material. Additionally, there are inserts that allow to position films or ionisation chamber in the phantom. Ten Polish radiotherapy centres (of 30 in total) were audited during on-site visits. Six different TPSs and five calculation algorithms were examined in the presence of inhomogeneities. Generally, most of the results from TLD were within 5 % tolerance. Differences between doses calculated by TPSs and measured with TLD did not exceed 4 % for bone and polystyrene equivalent materials. Under the lung equivalent material, on the beam axis the differences were lower than 5 %, whereas inside the lung equivalent material, off the beam axis, in some cases they were of around 7 %. The TLD results were confirmed with the ionisation chamber measurements. The comparison results of the calculations and the measurements allow to detect limitations of TPS calculation algorithms. The audits performed with the use of heterogeneous phantom and TLD seem to be an effective tool for detecting the limitations in the TPS performance or beam configuration errors at audited radiotherapy departments. PMID:25848119

  8. Neutron dosimetry in containment of a pressurized water reactor utilizing the Panasonic UD-802 dosimetry system

    SciTech Connect

    Kralick, S.C.

    1984-01-01

    The Panasonic UD-802 dosimeter was evaluated as a potential neutron dosimeter for use in containment of a PWR. The Panasonic UD-802 dosimeter, although designed as a beta and gamma dosimeter, is also sensitive to neutrons. UD-802 dosimeters were mounted on polyethylene phantoms and irradiated to known doses at selected locations in containment. The known neutron dose equivalents were determined based on remmeter dose rate measurements and stay times. The thermoluminescent response of the dosimeters and the known neutron dose equivalents were used to obtain a calibration factor at each location. The average calibration factor was 3.7 (unit of dosimeter response per mrem) and all calibration factors were within +-30% of this mean value. The dosimeter distance from the phantom was found to have minimal effect on the response but the system was directionally dependent, necessitating a correction in the calibration factor. The minimum significant dosimeter response was determined independent of any calibration factor. The minimum significant response of the UD-802 to neutrons is a function of the corresponding gamma exposure rate. It is concluded that the Panasonic UD-802 dosimeter can be used for neutron dosimetry in PWR containment.

  9. Comparison of Different Internal Dosimetry Systems for Selected Radionuclides Important to Nuclear Power Production

    SciTech Connect

    Leggett, Richard Wayne; Eckerman, Keith F; Manger, Ryan P

    2013-08-01

    This report compares three different radiation dosimetry systems currently applied by various U.S. Federal agencies and dose estimates based on these three dosimetry systems for a set of radionuclides often identified in power reactor effluents. These dosimetry systems were developed and applied by the International Commission on Radiological Protection at different times over the past six decades. Two primary modes of intake of radionuclides are addressed: ingestion in drinking water and inhalation. Estimated doses to individual organs and to the whole body based on each dosimetry system are compared for each of four age groups: infant, child, teenager, and adult. Substantial differences between dosimetry systems in estimated dose per unit intake are found for some individual radionuclides, but differences in estimated dose per unit intake generally are modest for mixtures of radionuclides typically found in nuclear power plant effluents.

  10. Performance of the CEDS Accident Dosimetry System at the 1995 Los Alamos National Laboratory Nuclear Accident Dosimetry Intercomparison

    SciTech Connect

    McMahan, K.L.; Schwanke, L.J.

    1996-12-01

    In July 1995, LANL hosted an accident dosimetry intercomparison. When all reactors on the Oak Ridge Reservation were idled in 1988, the Health Physics Research Reactor (HPRR), which had been used for 22 previous intercomparisons dating from 1965, was shut down for an indefinite period. The LANL group began characterization of two critical assemblies for dosimetry purposes. As a result, NAD-23 was conceived and 10 DOE facilities accepted invitations to participate in the intercomparison. This report is a summary of the performance of one of the participants, the Centralized External Dosimetry System (CEDS). The CEDS is a cooperative personnel dosimetry arrangement between three DOE sites in Oak Ridge, Tennessee. Many successes and failures are reported herein. Generally, the TL dosimeters performed poorly and always over-reported the delivered dose. The TLD processing procedures contain efforts that would lead to large biases in the reported absorbed dose, and omit several key steps in the TLD reading process. The supralinear behavior of lithium fluoride (LiF) has not been characterized for this particular dosimeter and application (i.e., in high-dose mixed neutron/gamma fields). The use of TLD materials may also be precluded given the limitations of the LiF material itself, the TLD reading system, and the upper dose level to which accident dosimetry systems are required to perform as set forth in DOE regulations. The indium foil results confirm the expected inability of that material to predict the magnitude of the wearer`s dose reliably, although it is quite suitable as a quick-sort material. Biological sample (hair) results were above the minimum detectable activity (MDA) for only one of the tests. Several questions as to the best methods for sample handling and processing remain.

  11. National and international standards and calibration of thermoluminescence dosimetry systems.

    PubMed

    Soares, C G

    2002-01-01

    Radiation protection for radiation workers, the public, and the environment is of international concern. The use of thermoluminescence dosemeters (TLD) is an acceptable method for dose recording in most countries. For reasons of consistency and data gathering (research) it is important that a Sievert (Sv) in one part of the world equals an Sv on the other side of the globe. To this end, much work has gone into the development of standards and calibration practices for TLD systems so that they compare not only with similar systems, but also with other forms of radiation measurement. While most national laboratories provide calibration services for these systems some, as in the United States, depend on services of secondary calibration laboratories that are traceable to the national laboratories through accreditation programmes. The purpose of this paper is to explain how TLD measurements are traceable to their respective national standards for both personnel and environmental dosimetry. PMID:12382728

  12. Section 9.1 new dosimeters. New dosimetry systems

    NASA Astrophysics Data System (ADS)

    McLaughlin, William L.

    During the past two years there have been significant advances in several forms of radiation measurement systems for radiation processing, covering dose ranges of 1-10 6 Gy. Calorimeters as reference standards for both ionizing photon and electron fields have become well-established. In addition to the older ceric-cerous dosimetry solution analyzed potentiometrically, new liquid-phase dosimeters include those analyzed by spectrophotometry, e.g., improved forms of acidic aqueous solutions of K-Ag dichromate and organic radiochromic dye solutions. It has recently been demonstrated that by using certain refined sugars, e.g., D-(-) ribose, optical rotation response in aqueous solutions can be enhanced for dosimetry at doses > 10 4 Gy. There has been expanded development, use, and formulation (rods, tablets, and thin films) of the amino acid, alanine, as a solid-phase dosimeter analyzed by either ESR spectrometry or by glutamine or alanine spectrophotometry of complexes with ferric ion in the presence of a sulfonphthalein dye (xylenol orange). New commercial types of radiochromic plastic dosimeters, e.g., GafChromic TM, Riso B3 TM, GAMMACHROME YR TM, Radix TM, and Gammex TM, have been introduced and applied in practice. Improvements and broader use of optical waveguide dosimeters, e.g., Opti-Chromic TM, have also been reported, especially in food irradiation applications. Several novel dyed plastic dosimeters are available in large quantities and they lose color due to irradiation. An example is a dyed cellulosic thin film (ATC type DY-42 TM) which can be measured spectrophotometrically or densitometrically up to doses as high as 10 6 Gy.

  13. US Department of Energy Laboratory Accredition Program (DOELAP) for personnel dosimetry systems

    SciTech Connect

    Cummings, F.M.; Carlson, R.D.; Loesch, R.M.

    1993-12-31

    Accreditation of personnel dosimetry systems is required for laboratories that conduct personnel dosimetry for the U.S. Department of Energy (DOE). Accreditation is a two-step process which requires the participant to pass a proficiency test and an onsite assessment. The DOE Laboratory Accreditation Program (DOELAP) is a measurement quality assurance program for DOE laboratories. Currently, the DOELAP addresses only dosimetry systems used to assess the whole body dose to personnel. A pilot extremity DOELAP has been completed and routine testing is expected to begin in January 1994. It is expected that participation in the extremity program will be a regulatory requirement by January 1996.

  14. AMS applied to Hiroshima and Chernobyl dosimetry

    SciTech Connect

    Straume, T.; Marchetti, A.A.; Anspaugh, L.R.

    1995-12-01

    Two projects employing AMS are summarized and updated. One project employs AMS to measure {sup 36}Cl in concrete and other mineral samples from Hiroshima and Nagasaki to help reconstruct neutron fluences received by the atom-bomb survivors. In this project, we have demonstrated a large discrepancy between the neutron activation measured in Hiroshima and predictions based on the current dosimetry system. This discrepancy has practical implications for radiation risk assessment and radiation protection standards. The other project employs AMS to measure {sup 129}I in soil and other environmental samples from Belarus, Ukraine, and Russia. This is a proof-of-principle study to determine if the long lived {sup 129}I isotope (half life, 16 x 10{sup 6} y) measured by AMS can be used to reconstruct deposition of the short lived {sup 131}I isotope from the 1986 Chernobyl reactor accident. This is required because {sup 131}I disappeared before adequate measurements could be made.

  15. TL dosimetry for quality control of CR mammography imaging systems

    NASA Astrophysics Data System (ADS)

    Gaona, E.; Nieto, J. A.; Góngora, J. A. I. D.; Arreola, M.; Enríquez, J. G. F.

    The aim of this work is to estimate the average glandular dose with thermoluminescent (TL) dosimetry and comparison with quality imaging in computed radiography (CR) mammography. For a measuring dose, the Food and Drug Administration (FDA) and the American College of Radiology (ACR) use a phantom, so that dose and image quality are assessed with the same test object. The mammography is a radiological image to visualize early biological manifestations of breast cancer. Digital systems have two types of image-capturing devices, full field digital mammography (FFDM) and CR mammography. In Mexico, there are several CR mammography systems in clinical use, but only one system has been approved for use by the FDA. Mammography CR uses a photostimulable phosphor detector (PSP) system. Most CR plates are made of 85% BaFBr and 15% BaFI doped with europium (Eu) commonly called barium flourohalideE We carry out an exploratory survey of six CR mammography units from three different manufacturers and six dedicated X-ray mammography units with fully automatic exposure. The results show three CR mammography units (50%) have a dose greater than 3.0 mGy without demonstrating improved image quality. The differences between doses averages from TLD system and dosimeter with ionization chamber are less than 10%. TLD system is a good option for average glandular dose measurement for X-rays with a HVL (0.35-0.38 mmAl) and kVp (24-26) used in quality control procedures with ACR Mammography Accreditation Phantom.

  16. Clinical implementation and rapid commissioning of an EPID based in-vivo dosimetry system.

    PubMed

    Hanson, Ian M; Hansen, Vibeke N; Olaciregui-Ruiz, Igor; van Herk, Marcel

    2014-10-01

    Using an Electronic Portal Imaging Device (EPID) to perform in-vivo dosimetry is one of the most effective and efficient methods of verifying the safe delivery of complex radiotherapy treatments. Previous work has detailed the development of an EPID based in-vivo dosimetry system that was subsequently used to replace pre-treatment dose verification of IMRT and VMAT plans. Here we show that this system can be readily implemented on a commercial megavoltage imaging platform without modification to EPID hardware and without impacting standard imaging procedures. The accuracy and practicality of the EPID in-vivo dosimetry system was confirmed through a comparison with traditional TLD in-vivo measurements performed on five prostate patients.The commissioning time required for the EPID in-vivo dosimetry system was initially prohibitive at approximately 10 h per linac. Here we present a method of calculating linac specific EPID dosimetry correction factors that allow a single energy specific commissioning model to be applied to EPID data from multiple linacs. Using this method reduced the required per linac commissioning time to approximately 30 min.The validity of this commissioning method has been tested by analysing in-vivo dosimetry results of 1220 patients acquired on seven linacs over a period of 5 years. The average deviation between EPID based isocentre dose and expected isocentre dose for these patients was (-0.7  ±  3.2)%.EPID based in-vivo dosimetry is now the primary in-vivo dosimetry tool used at our centre and has replaced nearly all pre-treatment dose verification of IMRT treatments. PMID:25211121

  17. Clinical implementation and rapid commissioning of an EPID based in-vivo dosimetry system

    NASA Astrophysics Data System (ADS)

    Hanson, Ian M.; Hansen, Vibeke N.; Olaciregui-Ruiz, Igor; van Herk, Marcel

    2014-10-01

    Using an Electronic Portal Imaging Device (EPID) to perform in-vivo dosimetry is one of the most effective and efficient methods of verifying the safe delivery of complex radiotherapy treatments. Previous work has detailed the development of an EPID based in-vivo dosimetry system that was subsequently used to replace pre-treatment dose verification of IMRT and VMAT plans. Here we show that this system can be readily implemented on a commercial megavoltage imaging platform without modification to EPID hardware and without impacting standard imaging procedures. The accuracy and practicality of the EPID in-vivo dosimetry system was confirmed through a comparison with traditional TLD in-vivo measurements performed on five prostate patients. The commissioning time required for the EPID in-vivo dosimetry system was initially prohibitive at approximately 10 h per linac. Here we present a method of calculating linac specific EPID dosimetry correction factors that allow a single energy specific commissioning model to be applied to EPID data from multiple linacs. Using this method reduced the required per linac commissioning time to approximately 30 min. The validity of this commissioning method has been tested by analysing in-vivo dosimetry results of 1220 patients acquired on seven linacs over a period of 5 years. The average deviation between EPID based isocentre dose and expected isocentre dose for these patients was (-0.7  ±  3.2)%. EPID based in-vivo dosimetry is now the primary in-vivo dosimetry tool used at our centre and has replaced nearly all pre-treatment dose verification of IMRT treatments.

  18. Verification of the dual integral glow analysis dosimetry system

    NASA Astrophysics Data System (ADS)

    Wagner, Eric Christopher

    2000-10-01

    The Dual Integral Glow Analysis (DINGA) method is a unique approach to the determination of the low-LET dose deposited within a thermoluminescent personnel dosimeter. DINGA creates its estimate of the dose deposited by utilizing the integrals of a sub-section of the glow curves obtained from opposite sides of one or more thermoluminescent detectors (TLDs) and knowledge of the TLDs thermophysical parameters. The performance of DINGA is evaluated with computational simulations for a variety of heating methods and error tolerance is also examined by introducing errors into the inputs the DINGA code. It has been found that DINGA's dose estimates are off approximately, in the worst case, the same percentage as the input parameter was varied. Experimental measurements are performed using a hot-gas heating method for large personnel doses and a laser heating method for smaller personnel doses with LiF: Mg, Ti (TLD-100) dosimeters. The dosimeters are exposed to select radiation fields generated by either certified sources or fields characterized by certified equipment. The DINGA dosimetry system is found to correctly report shallow and deep dose well within the limits required for certification by the National Voluntary Accreditation Program. The worst performance quotient is 0.19, well below the strictest limit of 0.30.

  19. Quality control program for the Hanford External Dosimetry thermoluminescent processing system

    SciTech Connect

    Baumgartner, W.V.; Endres, A.W.; Reese, S.R.

    1992-09-01

    The Hanford External Dosimetry Program is operated by Pacific Northwest Laboratory for the US Department of Energy (DOE). The program records official external occupational radiation doses for all Hanford Site employees and visitors in compliance with DOE Order requirements. This report documents the quality control (QC) program for External Dosimetry`s thermoluminescent dosimeter (TLD) processing system. The focus of the External Dosimetry Program has been (1) to accurately calculate personnel radiation doses, and (2) to document the methods used to report doses in order, to meet DOE Laboratory Accreditation Program (DOELAP) criteria. The purpose of this report is to describe the QC procedures used for dosimeters and processing equipment. Use of QC procedures allows for the prompt correction of unusual data before it is reported.

  20. An upgraded personnel dosimetry system for TMI-2 (Three Mile Island Unit 2)

    SciTech Connect

    Schmidt, J.W.; Harworth J.M.

    1988-01-01

    Following the Three Mile Island Unit 2 (TMI-2) accident, it was identified that due to the unusual radiological conditions created, an improved thermoluminescent dosimetry (TLD) system was needed to support the cleanup and recovery. The deficiencies of the existing system were identified as an unsuitable dosimeter design and limited system automation available to support the /approx/6000 dosimeters being processed monthly for record dose. As a result, a Panasonic-based TLD personnel dosimetry system was developed and installed by GPU Nuclear at the TMI facility. The components of this dosimetry system include a dosimeter design and associated interpretation algorithm, an extensive quality assurance program, and a computer-based dosimeter processing system. This dosimeter/algorithm design provides for the use of a changing beta correction factor (BCF), which is derived from beta spectral data collected by the dosimeter. The system computer-based processing equipment is driven using software developed to be user friendly, totally menu driven, and geared toward the implementation of an extensive quality assurance program for a production dosimetry system. In total, this software consists of over 95 programs that specifically support written dosimetry procedures.

  1. Genetic background of hyperphenylalaninemia in Nagasaki, Japan.

    PubMed

    Dateki, Sumito; Watanabe, Satoshi; Nakatomi, Akiko; Kinoshita, Eiichi; Matsumoto, Tadashi; Yoshiura, Koh-Ichiro; Moriuchi, Hiroyuki

    2016-05-01

    Phenylketonuria (PKU) and related hyperphenylalaninemia (HPA) are caused by a deficiency in hepatic phenylalanine hydroxylase (PAH). The incidence of PKU in Nagasaki prefecture is higher than that in all parts of Japan (1/15 894 vs 1/120 000). To investigate the genetic background of patients with HPA in Nagasaki prefecture, mutation analysis was done in 14 patients with PKU or mild HPA. Homozygous or compound heterozygous PAH mutations were identified in all the patients. The spectrum of PAH mutations in the cohort was broad and similar to those in all parts of Japan and East Asian countries. R53H is the most common mutation in patients with mild HPA. The present results provide further support for genotype-phenotype correlations in patients with HPA. The high incidence of PKU in Nagasaki, the westernmost part of Japan, might be due to migration of people with PAH mutations from China and Korea, and geographic factors. PMID:27173423

  2. Workshop Report on Atomic Bomb Dosimetry--Residual Radiation Exposure: Recent Research and Suggestions for Future Studies

    SciTech Connect

    2013-06-06

    There is a need for accurate dosimetry for studies of health effects in the Japanese atomic bomb survivors because of the important role that these studies play in worldwide radiation protection standards. International experts have developed dosimetry systems, such as the Dosimetry System 2002 (DS02), which assess the initial radiation exposure to gamma rays and neutrons but only briefly consider the possibility of some minimal contribution to the total body dose by residual radiation exposure. In recognition of the need for an up-to-date review of the topic of residual radiation exposure in Hiroshima and Nagasaki, recently reported studies were reviewed at a technical session at the 57th Annual Meeting of the Health Physics Society in Sacramento, California, 22-26 July 2012. A one-day workshop was also held to provide time for detailed discussion of these newer studies and to evaluate their potential use in clarifying the residual radiation exposures to the atomic-bomb survivors at Hiroshima and Nagasaki. Suggestions for possible future studies are also included in this workshop report.

  3. Workshop report on atomic bomb dosimetry-residual radiation exposure: recent research and suggestions for future studies.

    PubMed

    Kerr, George D; Egbert, Stephen D; Al-Nabulsi, Isaf; Beck, Harold L; Cullings, Harry M; Endo, Satoru; Hoshi, Masaharu; Imanaka, Tetsuji; Kaul, Dean C; Maruyama, Satoshi; Reeves, Glen I; Ruehm, Werner; Sakaguchi, Aya; Simon, Steven L; Spriggs, Gregory D; Stram, Daniel O; Tonda, Tetsuji; Weiss, Joseph F; Weitz, Ronald L; Young, Robert W

    2013-08-01

    There is a need for accurate dosimetry for studies of health effects in the Japanese atomic bomb survivors because of the important role that these studies play in worldwide radiation protection standards. International experts have developed dosimetry systems, such as the Dosimetry System 2002 (DS02), which assess the initial radiation exposure to gamma rays and neutrons but only briefly consider the possibility of some minimal contribution to the total body dose by residual radiation exposure. In recognition of the need for an up-to-date review of the topic of residual radiation exposure in Hiroshima and Nagasaki, recently reported studies were reviewed at a technical session at the 57th Annual Meeting of the Health Physics Society in Sacramento, California, 22-26 July 2012. A one-day workshop was also held to provide time for detailed discussion of these newer studies and to evaluate their potential use in clarifying the residual radiation exposures to the atomic-bomb survivors at Hiroshima and Nagasaki. Suggestions for possible future studies are also included in this workshop report. PMID:23799498

  4. Development of an alanine dosimetry system for radiation dose measurements in the radiotherapy range

    NASA Astrophysics Data System (ADS)

    Gago-Arias, A.; González-Castaño, D. M.; Gómez, F.; Peteiro, E.; Lodeiro, C.; Pardo-Montero, J.

    2015-08-01

    Alanine/ESR systems provide an interesting alternative to standard dosimetry systems like solid state or gas ionization chambers for dosimetry in radiotherapy. This is primarily due to the negligible energy dependence, high stability, and the possibility of using small pellets that are especially suitable for the dosimetry of small fields. In order to obtain acceptable dose uncertainties in the radiotherapy dose range, the setup, operational parameters and quantification methods need to be carefully investigated and optimized. In this work we present the development of an alanine/ESR dosimetry system, traced to the secondary standard laboratory of absorbed dose to water at the Radiation Physics Laboratory of the Universidade de Santiago de Compostela (Spain). We focus on the setup, the optimization of the operational parameters of the ESR spectrometer, the quantification of the readout signal and the construction of a calibration curve. The evaluation of the uncertainty budget is also a key component of an alanine/ESR system for radiotherapy dosimetry, and is presented in detail.After the optimization of the procedures, we have achieved a relative uncertainty of 1.7% (k=2) for an absorbed dose of 10 Gy, decreasing to 0.9% for 50 Gy.

  5. The LD50 associated with exposure to the atomic bombing of Hiroshima and Nagasaki.

    PubMed

    Fujita, S; Kato, H; Schull, W J

    1991-03-01

    Numerous attempts have been made to estimate the distance at which 50% of the individuals exposed to the A-bombing of Hiroshima and Nagasaki died, ostensibly from their exposure to ionizing radiation. It is difficult to convert most of these distance estimates to a dose-related LD50, since radiation shielding was ignored. The recent reassessment of the atomic bomb radiation dosimetry has provided an opportunity for the estimation of the bone marrow LD50. There is a surprising concordance in the various estimates that have been made given the different groups of survivors involved and the methods used to estimate the LD50/60. PMID:1762100

  6. Optimizing the dynamic range extension of a radiochromic film dosimetry system

    SciTech Connect

    Devic, Slobodan; Tomic, Nada; Soares, Christopher G.; Podgorsak, Ervin B.

    2009-02-15

    The authors present a radiochromic film dosimetry protocol for a multicolor channel radiochromic film dosimetry system consisting of the external beam therapy (EBT) model GAFCHROMIC film and the Epson Expression 1680 flat-bed document scanner. Instead of extracting only the red color channel, the authors are using all three color channels in the absorption spectrum of the EBT film to extend the dynamic dose range of the radiochromic film dosimetry system. By optimizing the dose range for each color channel, they obtained a system that has both precision and accuracy below 1.5%, and the optimized ranges are 0-4 Gy for the red channel, 4-50 Gy for the green channel, and above 50 Gy for the blue channel.

  7. Applicability study on existing dosimetry systems to high-power Bremsstrahlung irradiation

    NASA Astrophysics Data System (ADS)

    Mehta, Kishor; Kojima, Takuji; Sunaga, Hiromi

    2003-12-01

    Applicability of the existing dosimetry systems to high-power Bremsstrahlung irradiation was investigated through a dose intercomparison study, where several dosimeters were irradiated in the dose range 4-12 kGy in identical polyethylene phantoms in a Bremsstrahlung beam obtained from a 5-MeV electron accelerator. Included in the study were alanine dosimeters molded by three different binders, three types of liquid dosimeters—ceric-cerous, dichromate and ethanol-chlorobenzen (ECB), and glutamine powder. The dosimeter responses for Bremsstrahlung radiation were analyzed at the issuing laboratories, and the dose values determined using calibration based on cobalt-60 gamma-ray irradiation. Dose values for all the three dose levels for all dosimetry systems were in good agreement—better than 3%. The results of the study demonstrate that these existing dosimetry systems have a potential for application to high-power Bremsstrahlung irradiation.

  8. Year 2000 compliance concerns with the ISA Thermoluminescent Dosimetry Data Processing (TL-DP) software system

    SciTech Connect

    Saviz, K.

    1998-05-26

    The year 2000 is rapidly approaching, and there is a good chance that computer systems that utilize two digit year dates will experience problems in retrieval of date information. The ISA Thermoluminescent Dosimetry Data Processing (TL-DP) software and computer system has been reviewed for Year 2000 compliance issues.

  9. Linearization of dose-response curve of the radiochromic film dosimetry system

    SciTech Connect

    Devic, Slobodan; Tomic, Nada; Aldelaijan, Saad; DeBlois, Francois; Seuntjens, Jan; Chan, Maria F.; Lewis, Dave

    2012-08-15

    Purpose: Despite numerous advantages of radiochromic film dosimeter (high spatial resolution, near tissue equivalence, low energy dependence) to measure a relative dose distribution with film, one needs to first measure an absolute dose (following previously established reference dosimetry protocol) and then convert measured absolute dose values into relative doses. In this work, we present result of our efforts to obtain a functional form that would linearize the inherently nonlinear dose-response curve of the radiochromic film dosimetry system. Methods: Functional form [{zeta}= (-1){center_dot}netOD{sup (2/3)}/ln(netOD)] was derived from calibration curves of various previously established radiochromic film dosimetry systems. In order to test the invariance of the proposed functional form with respect to the film model used we tested it with three different GAFCHROMIC Trade-Mark-Sign film models (EBT, EBT2, and EBT3) irradiated to various doses and scanned on a same scanner. For one of the film models (EBT2), we tested the invariance of the functional form to the scanner model used by scanning irradiated film pieces with three different flatbed scanner models (Epson V700, 1680, and 10000XL). To test our hypothesis that the proposed functional argument linearizes the response of the radiochromic film dosimetry system, verification tests have been performed in clinical applications: percent depth dose measurements, IMRT quality assurance (QA), and brachytherapy QA. Results: Obtained R{sup 2} values indicate that the choice of the functional form of the new argument appropriately linearizes the dose response of the radiochromic film dosimetry system we used. The linear behavior was insensitive to both film model and flatbed scanner model used. Measured PDD values using the green channel response of the GAFCHROMIC Trade-Mark-Sign EBT3 film model are well within {+-}2% window of the local relative dose value when compared to the tabulated Cobalt-60 data. It was also

  10. Quality control program for the Hanford External Dosimetry thermoluminescent processing system

    SciTech Connect

    Baumgartner, W.V.; Endres, A.W.; Reese, S.R.

    1992-09-01

    The Hanford External Dosimetry Program is operated by Pacific Northwest Laboratory for the US Department of Energy (DOE). The program records official external occupational radiation doses for all Hanford Site employees and visitors in compliance with DOE Order requirements. This report documents the quality control (QC) program for External Dosimetry's thermoluminescent dosimeter (TLD) processing system. The focus of the External Dosimetry Program has been (1) to accurately calculate personnel radiation doses, and (2) to document the methods used to report doses in order, to meet DOE Laboratory Accreditation Program (DOELAP) criteria. The purpose of this report is to describe the QC procedures used for dosimeters and processing equipment. Use of QC procedures allows for the prompt correction of unusual data before it is reported.

  11. Review of US Army ionizing-radiation dosimetry system. Final report

    SciTech Connect

    Not Available

    1986-01-01

    Army civilian and military personnel are exposed occupationally to various forms of ionizing radiation, and the U.S. Army Ionizing Radiation Dosimetry Center is responsible for monitoring these exposures. There are several accepted methods for monitoring radiation exposure, the oldest being the film badge method. A modern alternative method, which has achieved widespread acceptance, is the thermoluminescent dosimeter (TLD) badge. Inasmuch as the Radiation Dosimetry Center is in the process of converting from film badges to TLD badges for radiation monitoring, the Army requested assistance on how it might optimize the transition to this new monitoring system.

  12. ASSESSMENT OF UNCERTAINTY IN THE RADIATION DOSES FOR THE TECHA RIVER DOSIMETRY SYSTEM

    SciTech Connect

    Napier, Bruce A.; Degteva, M. O.; Anspaugh, L. R.; Shagina, N. B.

    2009-10-23

    In order to provide more accurate and precise estimates of individual dose (and thus more precise estimates of radiation risk) for the members of the ETRC, a new dosimetric calculation system, the Techa River Dosimetry System-2009 (TRDS-2009) has been prepared. The deterministic version of the improved dosimetry system TRDS-2009D was basically completed in April 2009. Recent developments in evaluation of dose-response models in light of uncertain dose have highlighted the importance of different types of uncertainties in the development of individual dose estimates. These include uncertain parameters that may be either shared or unshared within the dosimetric cohort, and also the nature of the type of uncertainty as aleatory or epistemic and either classical or Berkson. This report identifies the nature of the various input parameters and calculational methods incorporated in the Techa River Dosimetry System (based on the TRDS-2009D implementation), with the intention of preparing a stochastic version to estimate the uncertainties in the dose estimates. This report reviews the equations, databases, and input parameters, and then identifies the author’s interpretations of their general nature. It presents the approach selected so that the stochastic, Monte-Carlo, implementation of the dosimetry System - TRDS-2009MC - will provide useful information regarding the uncertainties of the doses.

  13. Experimental analysis of a novel and low-cost pin photodiode dosimetry system for diagnostic radiology

    NASA Astrophysics Data System (ADS)

    Nazififard, Mohammad; Suh, Kune Y.; Mahmoudieh, Afshin

    2016-07-01

    Silicon PIN photodiode has recently found broad and exciting applications in the ionizing radiation dosimetry. In this study a compact and novel dosimetry system using a commercially available PIN photodiode (BPW34) has been experimentally tested for diagnostic radiology. The system was evaluated with clinical beams routinely used for diagnostic radiology and calibrated using a secondary reference standard. Measured dose with PIN photodiode (Air Kerma) varied from 10 to 430 μGy for tube voltages from 40 to 100 kVp and tube current from 0.4 to 40 mAs. The minimum detectable organ dose was estimated to be 10 μGy with 20% uncertainty. Results showed a linear correlation between the PIN photodiode readout and dose measured with standard dosimeters spanning doses received. The present dosimetry system having advantages of suitable sensitivity with immediate readout of dose values, low cost, and portability could be used as an alternative to passive dosimetry system such as thermoluminescent dosimeter for dose measurements in diagnostic radiology.

  14. Evaluation of Effective Sources in Uncertainty Measurements of Personal Dosimetry by a Harshaw TLD System

    PubMed Central

    Hosseini Pooya, SM; Orouji, T

    2014-01-01

    Background: The accurate results of the individual doses in personal dosimety which are reported by the service providers in personal dosimetry are very important. There are national / international criteria for acceptable dosimetry system performance. Objective: In this research, the sources of uncertainties are identified, measured and calculated in a personal dosimetry system by TLD. Method: These sources are included; inhomogeneity of TLDs sensitivity, variability of TLD readings due to limited sensitivity and background, energy dependence, directional dependence, non-linearity of the response, fading, dependent on ambient temperature / humidity and calibration errors, which may affect on the dose responses. Some parameters which influence on the above sources of uncertainty are studied for Harshaw TLD-100 cards dosimeters as well as the hot gas Harshaw 6600 TLD reader system. Results: The individual uncertainties of each sources was measured less than 6.7% in 68% confidence level. The total uncertainty was calculated 17.5% with 95% confidence level. Conclusion: The TLD-100 personal dosimeters as well as the Harshaw TLD-100 reader 6600 system show the total uncertainty value which is less than that of admissible value of 42% for personal dosimetry services. PMID:25505769

  15. GENII: The Hanford Environmental Radiation Dosimetry Software System: Volume 1, Conceptual representation

    SciTech Connect

    Napier, B.A.; Peloquin, R.A.; Strenge, D.L.; Ramsdell, J.V.

    1988-12-01

    The Hanford Environmental Dosimetry Upgrade Project was undertaken to incorporate the internal dosimetry models recommended by the International Commission on Radiological Protection (ICRP) in updated versions of the environmental pathway analysis models used at Hanford. The resulting second generation of Hanford environmental dosimetry computer codes is compiled in the Hanford Environmental Dosimetry System (Generation II, or GENII). The purpose of this coupled system of computer codes is to analyze environmental contamination resulting from acute or chronic releases to, or initial contamination of, air, water, or soil. This is accomplished by calculating radiation doses to individuals or populations. GENII is described in three volumes of documentation. The first volume describes the theoretical considerations of the system. The second volume is a Users' Manual, providing code structure, users' instructions, required system configurations, and QA-related topics. The third volume is a Code Maintenance Manual for the user who requires knowledge of code detail. It includes code logic diagrams, global dictionary, worksheets, example hand calculations, and listings of the code and its associated data libraries. 72 refs., 15 figs., 34 tabs.

  16. Criticality accident dosimetry systems: an international intercomparison at the SILENE reactor in 2002.

    PubMed

    Médioni, R; Asselineau, B; Verrey, B; Trompier, F; Itié, C; Texier, C; Muller, H; Pelcot, G; Clairand, I; Jacquet, X; Pochat, J L

    2004-01-01

    In criticality accident dosimetry and more generally for high dose measurements, special techniques are used to measure separately the gamma ray and neutron components of the dose. To improve these techniques and to check their dosimetry systems (physical and/or biological), a total of 60 laboratories from 29 countries (America, Europe, Asia) participated in an international intercomparaison, which took place in France from 9 to 21 June 2002, at the SILENE reactor in Valduc and at a pure gamma source in Fontenay-aux-Roses. This intercomparison was jointly organised by the IRSN and the CEA with the help of the NEA/OCDE and was partly supported by the European Communities. This paper describes the aim of this intercomparison, the techniques used by the participants and the two radiation sources and their characteristics. The experimental arrangements of the dosemeters for the irradiations in free air or on phantoms are given. Then the dosimetric quantities measured and reported by the participants are summarised, analysed and compared with the reference values. The present paper concerns only the physical dosimetry and essentially experiments performed on the SILENE facility. The results obtained with the biological dosimetry are published in two other papers of this issue. PMID:15353686

  17. Dose algorithm determination for the Los Alamos National Laboratory personnel dosimetry system

    SciTech Connect

    Patterson, J.M.

    1995-12-31

    One of the most important aspects of a TLD dosimetry system is the dose algorithm used to convert the signals from the badge reader to an estimate of a worker`s dose. It is now more important then ever to have an accurate algorithm to estimate dose well below regulatory limits. Dosimetry systems for DOE laboratories must meet minimum performance standards based on DOELAP criteria. The purpose of this paper is to describe the development of a dose algorithm for a new TLD dosimeter that has been developed at Los Alamos National Laboratories. It is expected that DOELAP testing will start in 1995. Initial results indicate that the system will be able to exceed the minimum performance criteria by a large margin. The enhanced ability of the dosimeter to determine beta, gamma, and neutron energies makes it very useful in the various radiation fields encountered at the laboratory.

  18. Neutron dosimetry in the containment of a pressurized water reactor using a neutron-sensitive beta/gamma dosimetry system

    SciTech Connect

    Kralick, S.C.; Watson, J.E. Jr.; Croslin, S.W.

    1986-06-01

    In this study the Panasonic UD-802 dosimeter was evaluated as a potential neutron dosimeter for use in the containment of a pressurized water reactor by comparing the results from the UD-802 with remmeter readings. The Panasonic UD-802 dosimeter is used routinely as a beta and gamma dosimeter but due to the natural Li and B in the thermoluminescent materials, it is also sensitive to neutrons. Since a dosimeter's response to neutrons is energy-dependent, proper calibration of the UD-802 in the environment for which it is to be used was an important consideration of the study. To calibrate the system, UD-802 dosimeters were mounted on polyethylene phantoms and irradiated to reference doses at selected locations in containment. The reference doses were determined based on remmeter dose-rate measurements and stay times. The thermoluminescent response of the dosimeters and the reference measurements were used to obtain a response ratio at each location. The average response ratio (unit of dosimeter response per millirem) was 3.7 and all response ratios were within +/-30% of this mean value. Specific characteristics of the UD-802 were also investigated, that is, the effects that dosimeter distance from the phantom and a person's movement through containment have on response. The dosimeter distance from the phantom was found to have a minimal effect on response, but the system was found to be dependent upon the angle of the phantom relative to the reactor core, necessitating a correction in the calibration factor. The overall conclusion of this study was that the Panasonic UD-802 dosimeter can be used for neutron dosimetry in containment of a pressurized water reactor.

  19. Alanine-EPR as a transfer standard dosimetry system for low energy X radiation

    NASA Astrophysics Data System (ADS)

    Khoury, H. J.; da Silva, E. J.; Mehta, K.; de Barros, V. S.; Asfora, V. K.; Guzzo, P. L.; Parker, A. G.

    2015-11-01

    The purpose of this paper is to evaluate the use of alanine-EPR as a transfer standard dosimetry system for low energy X radiation, such as that in RS-2400, which operates in the range from 25 to 150 kV and 2 to 45 mA. Two types of alanine dosimeters were investigated. One is a commercial alanine pellets from Aérial-Centre de Ressources Technologiques, France and one was prepared in our laboratory (LMRI-DEN/UFPE). The EPR spectra of the irradiated dosimeters were recorded in the Nuclear Energy Department of UFPE, using a Bruker EMX10 EPR spectrometer operating in the X-band. The alanine-EPR dosimetry system was calibrated in the range of 20-220 Gy in this X-ray field, against an ionization chamber calibrated at the relevant X-ray energy with traceability to PTB. The results showed that both alanine dosimeters presented a linear dose response the same sensitivity, when the EPR signal was normalized to alanine mass. The total uncertainty in the measured dose was estimated to be about 3%. The results indicate that it is possible to use the alanine-EPR dosimetry system for validation of a low-energy X ray irradiator, such as RS-2400.

  20. Desktop exposure system and dosimetry for small scale in vivo radiofrequency exposure experiments.

    PubMed

    Gong, Yijian; Capstick, Myles; Tillmann, Thomas; Dasenbrock, Clemens; Samaras, Theodoros; Kuster, Niels

    2016-01-01

    This paper describes a new approach to the risk assessment of exposure from wireless network devices, including an exposure setup and dosimetric assessment for in vivo studies. A novel desktop reverberation chamber has been developed for well-controlled exposure of mice for up to 24 h per day to address the biological impact of human exposure scenarios by wireless networks. The carrier frequency of 2.45 GHz corresponds to one of the major bands used in data communication networks and is modulated by various modulation schemes, including Global System for Mobile Communications (GSM), Universal Mobile Telecommunications System (UMTS), Radio Frequency Identification (RFID), and wireless local area network, etc. The system has been designed to enable exposures of whole-body averaged specific absorption rate (SAR) of up to 15 W/kg for six mice of an average weight of 25 g or of up to 320 V/m incident time-averaged fields under loaded conditions without distortion of the signal. The dosimetry for whole-body SAR and organ-averaged SAR of the exposed mice, with analysis of uncertainty and variation analysis, is assessed. The experimental dosimetry based on temperature measurement agrees well with the numerical dosimetry, with a very good SAR uniformity of 0.4 dB in the chamber. Furthermore, a thermal analysis and measurements were performed to provide better understanding of the temperature load and distribution in the mice during exposure. PMID:26769169

  1. Experimental active and passive dosimetry systems for the NASA Skylab program

    NASA Technical Reports Server (NTRS)

    Schneider, M. F.; Janni, J. F.; Ainsworth, G. C.

    1972-01-01

    Active and passive dosimetry instrumentation to measure absorbed dose, charged particle spectra, and linear energy transfer spectra inside the command module and orbital workshop on the Skylab program were developed and tested. The active dosimetry system consists of one integral unit employing both a tissue equivalent ionization chamber and silicon solid state detectors. The instrument measures dose rates from 0.2 millirad/hour to 25 rads/hour, linear energy transfer spectra from 2.8 to 42.4 Kev/micron, and the proton and alpha particle energy spectra from 0.5 to 75 Mev. The active dosimeter is equipped with a portable radiation sensor for use in astronaut on-body and spacecraft shielding surveys during passage of the Skylab through significant space radiations. Data are transmitted in real time or are recorded by onboard spacecraft tape recorder for rapid evaluation of the radiation levels. The passive dosimetry systems consist of twelve (12) hard-mounted assemblies, each containing a variety of passive radiation sensors which are recoverable at the end of the mission for analysis.

  2. Radiation field associated with Hiroshima and Nagasaki

    SciTech Connect

    Loewe, W.E.

    1984-08-01

    Accuracy of dosimetric estimates can determine the value of the atomic bomb survivor experience in establishing radiation risks. The status of a major revision of this dosimetry, initiated in 1980, is assessed. 3 references, 6 figures.

  3. 1983 international intercomparison of nuclear accident dosimetry systems at Oak Ridge National Laboratory

    SciTech Connect

    Swaja, R.E.; Greene, R.T.; Sims, C.S.

    1985-04-01

    An international intercomparison of nuclear accident dosimetry systems was conducted during September 12-16, 1983, at Oak Ridge National Laboratory (ORNL) using the Health Physics Research Reactor operated in the pulse mode to simulate criticality accidents. This study marked the twentieth in a series of annual accident dosimetry intercomparisons conducted at ORNL. Participants from ten organizations attended this intercomparison and measured neutron and gamma doses at area monitoring stations and on phantoms for three different shield conditions. Results of this study indicate that foil activation techniques are the most popular and accurate method of determining accident-level neutron doses at area monitoring stations. For personnel monitoring, foil activation, blood sodium activation, and thermoluminescent (TL) methods are all capable of providing accurate dose estimates in a variety of radiation fields. All participants in this study used TLD's to determine gamma doses with very good results on the average. Chemical dosemeters were also shown to be capable of yielding accurate estimates of total neutron plus gamma doses in a variety of radiation fields. While 83% of all neutron measurements satisfied regulatory standards relative to reference values, only 39% of all gamma results satisfied corresponding guidelines for gamma measurements. These results indicate that continued improvement in accident dosimetry evaluation and measurement techniques is needed.

  4. Evaluation of a computed radiography system for megavoltage photon beam dosimetry.

    PubMed

    Olch, Arthur J

    2005-09-01

    Computed radiography (CR) systems have been gaining adoption as digital replacements for film for diagnostic and therapy imaging. As a result, film processors are being removed from service, leaving a void for the medical physicists who use film and processors for two-dimensional mega-voltage beam dosimetry. This is the first report to evaluate the ability of a commercial CR reader and storage phosphor plate system to accurately quantitate absolute dose and dose distributions from a 6 MV photon beam. There are potential advantages and disadvantages of current CR systems compared to film systems. CR systems inherently produce a linear dose-response over several logs of dose. However, the barium in the storage phosphor has a higher atomic number than the silver in film, resulting in significant energy sensitivity. The purpose of this work is to fully characterize the impact of these and other features of this CR system relevant to dosimetry. The tests performed and reported on in this study include uniformity of readout across a uniform field, geometrical accuracy, intra- and interday reproducibility, signal decay with time and with light exposure, dose-to-signal calibration, high dose effects, obliquity effects, perpendicular and parallel calibration results, field size and depth of measurement effects and the use of lead filters to minimize them, and intensity modulated radiation therapy quality assurance test results compared to that for film. Practical techniques are provided to optimize the accuracy of the system as a dosimetric replacement for film. PMID:16266113

  5. A comprehensive evaluation of the PRESAGE/optical-CT 3D dosimetry system.

    PubMed

    Sakhalkar, H S; Adamovics, J; Ibbott, G; Oldham, M

    2009-01-01

    This work presents extensive investigations to evaluate the robustness (intradosimeter consistency and temporal stability of response), reproducibility, precision, and accuracy of a relatively new 3D dosimetry system comprising a leuco-dye doped plastic 3D dosimeter (PRESAGE) and a commercial optical-CT scanner (OCTOPUS 5x scanner from MGS Research, Inc). Four identical PRESAGE 3D dosimeters were created such that they were compatible with the Radiologic Physics Center (RPC) head-and-neck (H&N) IMRT credentialing phantom. Each dosimeter was irradiated with a rotationally symmetric arrangement of nine identical small fields (1 x 3 cm2) impinging on the flat circular face of the dosimeter. A repetitious sequence of three dose levels (4, 2.88, and 1.28 Gy) was delivered. The rotationally symmetric treatment resulted in a dose distribution with high spatial variation in axial planes but only gradual variation with depth along the long axis of the dosimeter. The significance of this treatment was that it facilitated accurate film dosimetry in the axial plane, for independent verification. Also, it enabled rigorous evaluation of robustness, reproducibility and accuracy of response, at the three dose levels. The OCTOPUS 5x commercial scanner was used for dose readout from the dosimeters at daily time intervals. The use of improved optics and acquisition technique yielded substantially improved noise characteristics (reduced to approximately 2%) than has been achieved previously. Intradosimeter uniformity of radiochromic response was evaluated by calculating a 3D gamma comparison between each dosimeter and axially rotated copies of the same dosimeter. This convenient technique exploits the rotational symmetry of the distribution. All points in the gamma comparison passed a 2% difference, 1 mm distance-to-agreement criteria indicating excellent intradosimeter uniformity even at low dose levels. Postirradiation, the dosimeters were all found to exhibit a slight increase in

  6. A comprehensive evaluation of the PRESAGE∕optical-CT 3D dosimetry system

    PubMed Central

    Sakhalkar, H. S.; Adamovics, J.; Ibbott, G.; Oldham, M.

    2009-01-01

    This work presents extensive investigations to evaluate the robustness (intradosimeter consistency and temporal stability of response), reproducibility, precision, and accuracy of a relatively new 3D dosimetry system comprising a leuco-dye doped plastic 3D dosimeter (PRESAGE) and a commercial optical-CT scanner (OCTOPUS 5× scanner from MGS Research, Inc). Four identical PRESAGE 3D dosimeters were created such that they were compatible with the Radiologic Physics Center (RPC) head-and-neck (H&N) IMRT credentialing phantom. Each dosimeter was irradiated with a rotationally symmetric arrangement of nine identical small fields (1×3 cm2) impinging on the flat circular face of the dosimeter. A repetitious sequence of three dose levels (4, 2.88, and 1.28 Gy) was delivered. The rotationally symmetric treatment resulted in a dose distribution with high spatial variation in axial planes but only gradual variation with depth along the long axis of the dosimeter. The significance of this treatment was that it facilitated accurate film dosimetry in the axial plane, for independent verification. Also, it enabled rigorous evaluation of robustness, reproducibility and accuracy of response, at the three dose levels. The OCTOPUS 5× commercial scanner was used for dose readout from the dosimeters at daily time intervals. The use of improved optics and acquisition technique yielded substantially improved noise characteristics (reduced to ∼2%) than has been achieved previously. Intradosimeter uniformity of radiochromic response was evaluated by calculating a 3D gamma comparison between each dosimeter and axially rotated copies of the same dosimeter. This convenient technique exploits the rotational symmetry of the distribution. All points in the gamma comparison passed a 2% difference, 1 mm distance-to-agreement criteria indicating excellent intradosimeter uniformity even at low dose levels. Postirradiation, the dosimeters were all found to exhibit a slight increase in opaqueness

  7. The neutron spectrum of the Hiroshima A-bomb and the Dosimetry System 1986

    NASA Astrophysics Data System (ADS)

    Rühm, W.; Kato, K.; Korschinek, G.; Morinaga, H.; Urban, A.; Zerle, L.; Nolte, E.

    1990-12-01

    The radioisotope 41Ca produced by the Hiroshima A-bomb in a gravestone 107 m from the hypocenter was measured with accelerator mass spectrometry (AMS) at the Munich accelerator laboratory. The resonance integral for the reaction 40Ca(n,γ) 41Ca was determined to be Iγ = (0.22 ± 0.02) b. This, together with γ spectrometric data on 60Co, 152Eu and 154Eu and AMS data on 36Cl from the same gravestone permitted deduction of the neutron energy spectrum and fluence at this distance in Hiroshima. The derived spectrum is much harder than the spectrum used in the Dosimetry System 1986, DS86.

  8. Is there an influence of the surrounding material on the response of the alanine dosimetry system?

    NASA Astrophysics Data System (ADS)

    Anton, Mathias; Kapsch, Ralf-Peter; Hackel, Thomas

    2009-04-01

    In a combined experimental and Monte Carlo study the possible influence of the surrounding material on the response of the alanine dosimetry system was investigated. The aim of this work was to estimate the uncertainties induced by the surroundings with respect to quality assurance measurements for radiotherapy, for example in humanoid phantoms. Six different materials were tested. The electron density range covered comprises the range present in human tissue. No significant influence of the surrounding material could be found for irradiations in the 60Co reference field of the Physikalisch-Technische Bundesanstalt (PTB).

  9. Development of Instrumental ORAM System for Radiation Dosimetry

    SciTech Connect

    Bogard, J.S.; Cullum, B.M.; Mobley, J.; Moscovitch, M.; Vo-Dinh, T.

    1999-09-01

    The development of an optical-based dosimeter for neutrons and heavy charged particles is described. It is based on the use of three dimensional (3-D) optical memory materials, used in optical computing applications, and multiphoton fluorescence of photochromic dyes. Development and characterization of various types of dosimeter materials are described as well as the optical readout system. In addition, various excitation geometries for ''reading'' and ''writing'' to the optical memories are also discussed.

  10. Dosimetry for radiobiological studies of the human hematopoietic system

    NASA Technical Reports Server (NTRS)

    Beck, W. L.; Stokes, T. R.; Lushbaugh, C. C.

    1972-01-01

    A system for estimating individual bone marrow doses in therapeutic radiation exposures of leukemia patients was studied. These measurements are used to make dose response correlations and to study the effect of dose protraction on peripheral blood cell levels. Three irradiators designed to produce a uniform field of high energy gamma radiation for total body exposures of large animals and man are also used for radiobiological studies.

  11. A portable electronic system for radiation dosimetry using electrets

    NASA Astrophysics Data System (ADS)

    Cruvinel, P. E.; Mascarenhas, S.; Cameron, J.

    1990-02-01

    An electret dosimeter with a cylindrical active volume has been introduced by Mascarenhas and collaborators [Proc. 10th Anniversary Conf. 1969-1979, Associacâo Brasileira de Fisicos em Medicina, p. 488; Topics Appl. Phys. 33 (1987) 321] for possible use in personnel and area monitoring. The full energy response curve as well as the degree of reproducibility and accuracy of the dosimeter are reported in a previous report [O. Guerrini, Master Science Thesis, São Carlos, USP-IFQSC (1982)]. For dimensions similar to those of the common pen dosimeter, the electret has a total surface charge of the order of 10 -9 C and it has a readout sensitivity of the order of 10 -5 Gy with a useful range of 5 × 10 -2 Gy. In this paper we describe a portable electronic system to measure X and γ-rays using a cylindrical electret ionization chamber. It uses commercially available operational amplifiers, and charge measurements can also be made by connecting a suitable capacitor in the feedback loop. With this system it is possible to measure equivalent surface charges up to (19.99±0.01) on the dosimeter. The readout doses are shown on a 3 {1}/{2} digit liquid crystal display (LCD). We have used complementary metal oxide semiconductor (CMOS) and bipolar metal oxide semiconductor (BiMOS) operatonal amplifier devices in the system's design. This choice provides small power consumption and is ideal for battery powered instruments. Furthermore the instrument is ideally suited for in situ measurements of X and γ radiation using a cylindrical electret ionization chamber.

  12. Dosimetry and image quality assessment in a direct radiography system

    PubMed Central

    Oliveira, Bruno Beraldo; de Oliveira, Marcio Alves; Paixão, Lucas; Teixeira, Maria Helena Araújo; Nogueira, Maria do Socorro

    2014-01-01

    Objective To evaluate the mean glandular dose with a solid state detector and the image quality in a direct radiography system, utilizing phantoms. Materials and Methods Irradiations were performed with automatic exposure control and polymethyl methacrylate slabs with different thicknesses to calculate glandular dose values. The image quality was evaluated by means of the structures visualized on the images of the phantoms. Results Considering the uncertainty of the measurements, the mean glandular dose results are in agreement with the values provided by the equipment and with internationally adopted reference levels. Results obtained from images of the phantoms were in agreement with the reference values. Conclusion The present study contributes to verify the equipment conformity as regards dose values and image quality. PMID:25741119

  13. X-Tream: a novel dosimetry system for Synchrotron Microbeam Radiation Therapy

    NASA Astrophysics Data System (ADS)

    Petasecca, M.; Cullen, A.; Fuduli, I.; Espinoza, A.; Porumb, C.; Stanton, C.; Aldosari, A. H.; Bräuer-Krisch, E.; Requardt, H.; Bravin, A.; Perevertaylo, V.; Rosenfeld, A. B.; Lerch, M. L. F.

    2012-07-01

    Microbeam Radiation Therapy (MRT) is a radiation treatment technique under development for inoperable brain tumors. MRT is based on the use of a synchrotron generated X-ray beam with an extremely high dose rate ( ~ 20 kGy/sec), striated into an array of X-ray micro-blades. In order to advance to clinical trials, a real-time dosimeter with excellent spatial resolution must be developed for absolute dosimetry. The design of a real-time dosimeter for such a radiation scenario represents a significant challenge due to the high photon flux and vertically striated radiation field, leading to very steep lateral dose gradients. This article analyses the striated radiation field in the context of the requirements for temporal dosimetric measurements and presents the architecture of a new dosimetry system based on the use of silicon detectors and fast data acquisition electronic interface. The combined system demonstrates micrometer spatial resolution and microsecond real time readout with accurate sensitivity and linearity over five orders of magnitude of input signal. The system will therefore be suitable patient treatment plan verification and may also be expanded for in-vivo beam monitoring for patient safety during the treatment.

  14. Dose Verification of Stereotactic Radiosurgery Treatment for Trigeminal Neuralgia with Presage 3D Dosimetry System

    NASA Astrophysics Data System (ADS)

    Wang, Z.; Thomas, A.; Newton, J.; Ibbott, G.; Deasy, J.; Oldham, M.

    2010-11-01

    Achieving adequate verification and quality-assurance (QA) for radiosurgery treatment of trigeminal-neuralgia (TGN) is particularly challenging because of the combination of very small fields, very high doses, and complex irradiation geometries (multiple gantry and couch combinations). TGN treatments have extreme requirements for dosimetry tools and QA techniques, to ensure adequate verification. In this work we evaluate the potential of Presage/Optical-CT dosimetry system as a tool for the verification of TGN distributions in high-resolution and in 3D. A TGN treatment was planned and delivered to a Presage 3D dosimeter positioned inside the Radiological-Physics-Center (RPC) head and neck IMRT credentialing phantom. A 6-arc treatment plan was created using the iPlan system, and a maximum dose of 80Gy was delivered with a Varian Trilogy machine. The delivered dose to Presage was determined by optical-CT scanning using the Duke Large field-of-view Optical-CT Scanner (DLOS) in 3D, with isotropic resolution of 0.7mm3. DLOS scanning and reconstruction took about 20minutes. 3D dose comparisons were made with the planning system. Good agreement was observed between the planned and measured 3D dose distributions, and this work provides strong support for the viability of Presage/Optical-CT as a highly useful new approach for verification of this complex technique.

  15. DS02 fluence spectra for neutrons and gamma rays at Hiroshima and Nagasaki with fluence-to-kerma coefficients and transmission factors for sample measurements.

    PubMed

    Egbert, Stephen D; Kerr, George D; Cullings, Harry M

    2007-11-01

    Fluence spectra at several ground distances in Hiroshima and Nagasaki are provided along with associated fluence-to-kerma coefficients from the Dosimetry System 2002 (DS02). Also included are transmission factors for calculating expected responses of in situ sample measurements of neutron activation products such as (32)P,(36)Cl,(39)Ar,(41)Ca, (60)Co,(63)Ni,(152)Eu, and (154)Eu. The free-in-air (FIA) fluences calculated in 2002 are available for 240 angles, 69 energy groups, 101 ground distances, 5 heights, 4 radiation source components, 2 cities. The DS02 code uses these fluences partitioned to a prompt and delayed portion, collapsed to 58 energy groups and restricted to 97 ground distances. This is because the fluence spectra were required to be in the same format that was used in the older Dosimetry System 1986 (DS86) computer code, of which the DS02 computer code is a modification. The 2002 calculation fluences and the collapsed DS02 code fluences are presented and briefly discussed. A report on DS02, which is available on the website at the Radiation Effects Research Foundation, provides tables and figures of the A-bomb neutron and gamma-ray output used as the sources in the 2002 radiation transport calculations. While figures illustrating the fluence spectra at several ground ranges are presented in the DS02 Report, it does not include any tables of the calculated fluence spectra in the DS02 report. This paper provides, at several standard distances from the hypocenter, the numerical information which is required to translate the FIA neutron fluences given in DS02 to a neutron activation measurement or neutron and gamma-ray soft-tissue dose. PMID:17643260

  16. Verification of intensity modulated radiation therapy beams using a tissue equivalent plastic scintillator dosimetry system

    NASA Astrophysics Data System (ADS)

    Petric, Martin Peter

    This thesis describes the development and implementation of a novel method for the dosimetric verification of intensity modulated radiation therapy (IMRT) fields with several advantages over current techniques. Through the use of a tissue equivalent plastic scintillator sheet viewed by a charge-coupled device (CCD) camera, this method provides a truly tissue equivalent dosimetry system capable of efficiently and accurately performing field-by-field verification of IMRT plans. This work was motivated by an initial study comparing two IMRT treatment planning systems. The clinical functionality of BrainLAB's BrainSCAN and Varian's Helios IMRT treatment planning systems were compared in terms of implementation and commissioning, dose optimization, and plan assessment. Implementation and commissioning revealed differences in the beam data required to characterize the beam prior to use with the BrainSCAN system requiring higher resolution data compared to Helios. This difference was found to impact on the ability of the systems to accurately calculate dose for highly modulated fields, with BrainSCAN being more successful than Helios. The dose optimization and plan assessment comparisons revealed that while both systems use considerably different optimization algorithms and user-control interfaces, they are both capable of producing substantially equivalent dose plans. The extensive use of dosimetric verification techniques in the IMRT treatment planning comparison study motivated the development and implementation of a novel IMRT dosimetric verification system. The system consists of a water-filled phantom with a tissue equivalent plastic scintillator sheet built into the top surface. Scintillation light is reflected by a plastic mirror within the phantom towards a viewing window where it is captured using a CCD camera. Optical photon spread is removed using a micro-louvre optical collimator and by deconvolving a glare kernel from the raw images. Characterization of this

  17. The 1983 international intercomparison of nuclear accident dosimetry systems at Oak Ridge National Laboratory

    NASA Astrophysics Data System (ADS)

    Swaja, R. E.; Greene, R. T.; Sims, C. S.

    1985-04-01

    An international intercomparison of nuclear accident dosimetry systems was conducted during September 12 to 16, 1983, at Oak Ridge National Laboratory (ORNL) using the Health Physics Research Reactor operated in the pulse mode to simulate criticality accidents. Participants measured neutron and gamma doses at area monitoring stations and on phantoms for three different shield conditions. Results indicate that foil activation techniques are the most popular and accurate method of determining accident level neutron doses at area monitoring stations. For personnel monitoring, foil activation, blood sodium activation, and thermoluminescent (TL) methods are all capable of providing accurate dose estimates in a variety of radiation fields. All participants used TLD's to determine gamma doses with very good results. Chemical dosimeters were also shown to be capable of yielding accurate estimates of total neutron plus gamma doses in a variety of radiation fields. While 83% of all neutron measurements satisfied regulatory standards relative to reference values, only 39% of all gamma results satisfied corresponding guidelines for gamma measurements. Results indicate that continued improvement in accident dosimetry evaluation and measurement techniques is needed.

  18. Department of Energy standard for the performance testing of personnel dosimetry systems

    SciTech Connect

    Not Available

    1986-12-01

    This standard is intended to be used in the Department of Energy Laboratory Accreditation Program (DOELAP) for personnel dosimetry systems. It is based on the American National Standards Institute's (ANSI) ''Criteria for Testing Personnel Dosimetry Performance,'' ANSI N13.11-1983, recommendations made to DOE in ''Guidelines for the Calibration of Personnel Dosimeters,'' Pacific Northwest Laboratory (PNL)-4515 and comments received during peer review by DOE and DOE contractor personnel. The recommendations contained in PNL-4515 were based on an evaluation of ANSI N13.11 conducted for the Office of Nuclear Safety, DOE, by PNL. Parts of ANSI N13.11 that did not require modification were used essentially intact in this standard to maintain consistency with nationally recognized standards. Modifications to this standard have resulted from several DOE/DOE contractor reviews and a pilot testing session. An initial peer review by selected DOE and DOE contractor representatives on technical content was conducted in 1983. A review by DOE field offices, program offices, and contractors was conducted in mid-1984. A pilot performance testing session sponsored by the Office of Nuclear Safety was conducted in early 1985 by the Radiological and Environmental Sciences Laboratory, Idaho Falls. Results of the pilot test were reviewed in late 1985 by a DOE and DOE contractor committee. 11 refs., 4 tabs.

  19. Automatic neutron dosimetry system based on fluorescent nuclear track detector technology.

    PubMed

    Akselrod, M S; Fomenko, V V; Bartz, J A; Haslett, T L

    2014-10-01

    For the first time, the authors are describing an automatic fluorescent nuclear track detector (FNTD) reader for neutron dosimetry. FNTD is a luminescent integrating type of detector made of aluminium oxide crystals that does not require electronics or batteries during irradiation. Non-destructive optical readout of the detector is performed using a confocal laser scanning fluorescence imaging with near-diffraction limited resolution. The fully automatic table-top reader allows one to load up to 216 detectors on a tray, read their engraved IDs using a CCD camera and optical character recognition, scan and process simultaneously two types of images in fluorescent and reflected laser light contrast to eliminate false-positive tracks related to surface and volume crystal imperfections. The FNTD dosimetry system allows one to measure neutron doses from 0.1 mSv to 20 Sv and covers neutron energies from thermal to 20 MeV. The reader is characterised by a robust, compact optical design, fast data processing electronics and user-friendly software. PMID:24285287

  20. Handbook for the Department of Energy Laboratory Accreditation Program for personnel dosimetry systems

    SciTech Connect

    Not Available

    1986-12-01

    The program contained in this Handbook provides a significant advance in the field of radiation protection through a structured means for assuring the quality of personnel dosimetry performance. Since personnel dosimetry performance is directly related to the assurance of worker safety, it has been of key interest to the Department of Energy. Studies conducted over the past three decades have clearly demonstrated a need for personnel dosimetry performance criteria, related testing programs, and improvements in dosimetry technology. In responding to these needs, the DOE Office of Nuclear Safety (EH) has developed and initiated a DOE Laboratory Accreditation Program (DOELAP) which is intended to improve the quality of personnel dosimetry through (1) performance testing, (2) dosimetry and calibration intercomparisons, and (3) applied research. In the interest of improving dosimetry technology, the DOE Laboratory Accreditation Program (DOELAP) is also designed to encourage cooperation and technical interchange between DOE laboratories. Dosimetry intercomparison programs have been scheduled which include the use of transport standard instruments, transport standard radioactive sources and special dosimeters. The dosimeters used in the intercomparison program are designed to obtain optimum data on the comparison of dosimetry calibration methodologies and capabilities. This data is used in part to develop enhanced calibration protocols. In the interest of overall calibration update, assistance and guidance for the calibration of personnel dosimeters is available through the DOELAP support laboratories. 20 refs., 1 tab.

  1. Evaluation of superficial dosimetry between treatment planning system and measurement for several breast cancer treatment techniques

    SciTech Connect

    Akino, Yuichi; Das, Indra J.; Bartlett, Gregory K.; Zhang Hualin; Thompson, Elizabeth; Zook, Jennifer E.

    2013-01-15

    Purpose: Dosimetric accuracy in radiation treatment of breast cancer is critical for the evaluation of cosmetic outcomes and survival. It is often considered that treatment planning systems (TPS) may not be able to provide accurate dosimetry in the buildup region. This was investigated in various treatment techniques such as tangential wedges, field-in-field (FF), electronic compensator (eComp), and intensity-modulated radiotherapy (IMRT). Methods: Under Institutional Review Board (IRB) exemption, radiotherapy treatment plans of 111 cases were retrospectively analyzed. The distance between skin surface and 95% isodose line was measured. For measurements, Gafchromic EBT2 films were used on a humanoid unsliced phantom. Multiple layers of variable thickness of superflab bolus were placed on the breast phantom and CT scanned for planning. Treatment plans were generated using four techniques with two different grid sizes (1 Multiplication-Sign 1 and 2.5 Multiplication-Sign 2.5 mm{sup 2}) to provide optimum dose distribution. Films were placed at different depths and exposed with the selected techniques. A calibration curve for dose versus pixel values was also generated on the same day as the phantom measurement was conducted. The DICOM RT image, dose, and plan data were imported to the in-house software. On axial plane of CT slices, curves were drawn at the position where EBT2 films were placed, and the dose profiles on the lines were acquired. The calculated and measured dose profiles were separated by check points which were marked on the films before irradiation. The segments of calculated profiles were stretched to match their resolutions to that of film dosimetry. Results: On review of treatment plans, the distance between skin and 95% prescribed dose was up to 8 mm for plans of 27 patients. The film measurement revealed that the medial region of phantom surface received a mere 45%-50% of prescribed dose. For wedges, FF, and eComp techniques, region around the

  2. Development of a 3-dimensional dosimetry system for Leksell Gamma Knife Perfexion

    NASA Astrophysics Data System (ADS)

    Yoon, KyoungJun; Kwak, JungWon; Lee, DoHeui; Cho, ByungChul; Lee, SangWook; Ahn, SeungDo

    2015-07-01

    The purpose of our study is to develop a new, 3-dimensional dosimetry system to verify the accuracy of dose deliveries in Leksell Gamma Knife Perfexion (LGKP) (Elekta, Norcross, GA, USA). The instrument consists of a moving head phantom, an embedded thin active layer and a CCD camera system and was designed to be mounted to LGKP. As an active material concentrically located in the hemispheric head phantom, we choose Gafchromic EBT3 films and Gd2O2S:Tb phosphor sheets for dosimetric measurements. Also, to compensate for the lack of backscatter, we located a 1-cm-thick poly methyl methacrylate (PMMA) plate downstream of the active layer. The PMMA plate was transparent to scintillation light to reach the CCD with 1200 × 1200 pixels and a 5.2 µm pitch. With this system, 300 images with a 0.2-mm slice gap were acquired under each of three collimator setups, i.e. 4-mm, 8-mm, and 16-mm, respectively. The 2D projected images taken by the CCD camera were compared with the dose distributions measured by the EBT3 films under the same conditions. All 2D distributions were normalized to the maximum values derived by fitting peaks for each collimator setup. The differences in the full widths at half maximum (FWHM) of 2D profiles between CCD images and film doses were measured to be less than 0.3-mm. The scanning task for all peak regions took less than three minutes with the new instrument. So it can be utilized as a QA tool for the Gamma knife radiosurgery system instead of film dosimetry, the use of which requires much more time and many more resources.

  3. Pre-treatment verification of intensity modulated radiation therapy plans using a commercial electronic portal dosimetry system.

    PubMed

    Roxby, Kathleen J; Crosbie, Jeffrey C

    2010-03-01

    We commissioned a commercially available portal dosimetry system for quality assurance of intensity modulated radiation therapy (IMRT) treatment plans. The system included gamma analysis software to compare the measured and predicted fluence maps from individual IMRT fields. The portal dosimetry system was tested using six head and neck IMRT patient plans, and we demonstrated that the accuracy of the alignment of measured and predicted images improved by retracting and repositioning the electronic portal imaging device (EPID) at each new gantry angle. The mean gamma score (fraction of pixels passing the gamma criteria) for the six test plans (after initial testing and using the EPID retracting and repositioning method) was 0.987 (2SD = 0.018), using gamma criteria of a dose difference of 2% of the maximum field dose and 2 mm distance to agreement. The mean gamma score was 0.989 (2SD = 0.017) for 24 head and neck IMRT patient plans carried out with portal dosimetry. Using gamma criteria of 2% maximum field dose and 2 mm distance to agreement, a gamma score tolerance of 0.980 is a useful way of highlighting only those fields requiring further analysis. Portal dosimetry is a quick way of assessing individual field fluence distributions and can be integrated into an IMRT quality assurance programme. PMID:20237893

  4. ASSESSMENT OF VARIOUS TYPES OF UNCERTAINTY IN THE TECHA RIVER DOSIMETRY SYSTEM

    SciTech Connect

    Napier, Bruce A.; Degteva, M. O.; Anspaugh, L. R.

    2008-09-01

    Recent developments in evaluation of dose-response models in light of uncertain dose data (Stram and Kopecky 2003; Schafer and Gilbert 2006) have highlighted the importance of different types of uncertainties in the development of individual dose estimates. These include uncertain parameters that may be either shared or unshared within the dosimetric cohort, and also the nature of the type of uncertainty as either classical or Berkson. This report is an initial attempt to identify the nature of the various input parameters and calculational methods incorporated in the Techa River Dosimetry System (based on the TRDS-2000 implementation as a starting point, with additions for recently-developed capabilities). This report reviews the database, equations, and input parameters, and then identifies the author's interpretations of their general nature. It closes with some questions for the users of the data (epidemiologists and biostatisticians), so that the next implantation of the TRDS will provide the most useful information.

  5. Determination of uncertainty components for a system in Radiation Protection Dosimetry

    NASA Astrophysics Data System (ADS)

    Lopez, F.; Cabral, T. S.; Peixoto, J. G.

    2015-01-01

    This work is about the theoretical calculation of uncertainties associated to the dosimetry of photons of a 137Cs source that will be used in a Dosimetry Laboratory. In this case recognition of the influence quantities that provide most uncertainty and the right choice of resolution of auxiliary equipment to obtain the smallest uncertainties according to the laboratory.

  6. Changes in Occupational Radiation Exposures after Incorporation of a Real-time Dosimetry System in the Interventional Radiology Suite.

    PubMed

    Poudel, Sashi; Weir, Lori; Dowling, Dawn; Medich, David C

    2016-08-01

    A statistical pilot study was retrospectively performed to analyze potential changes in occupational radiation exposures to Interventional Radiology (IR) staff at Lawrence General Hospital after implementation of the i2 Active Radiation Dosimetry System (Unfors RaySafe Inc, 6045 Cochran Road Cleveland, OH 44139-3302). In this study, the monthly OSL dosimetry records obtained during the eight-month period prior to i2 implementation were normalized to the number of procedures performed during each month and statistically compared to the normalized dosimetry records obtained for the 8-mo period after i2 implementation. The resulting statistics included calculation of the mean and standard deviation of the dose equivalences per procedure and included appropriate hypothesis tests to assess for statistically valid differences between the pre and post i2 study periods. Hypothesis testing was performed on three groups of staff present during an IR procedure: The first group included all members of the IR staff, the second group consisted of the IR radiologists, and the third group consisted of the IR technician staff. After implementing the i2 active dosimetry system, participating members of the Lawrence General IR staff had a reduction in the average dose equivalence per procedure of 43.1% ± 16.7% (p = 0.04). Similarly, Lawrence General IR radiologists had a 65.8% ± 33.6% (p=0.01) reduction while the technologists had a 45.0% ± 14.4% (p=0.03) reduction. PMID:27356166

  7. SU-E-T-104: Development of 3 Dimensional Dosimetry System for Gamma Knife

    SciTech Connect

    Yoon, K; Kwak, J; Cho, B; Lee, D; Ahn, S

    2014-06-01

    Purpose: The aim of this study was to develop a new 3 dimensional dosimetry system to verify the dosimetric accuracy of Leksell Gamma Knife-Perfexion™ (LGK) (Elekta, Norcross, GA). Methods: We designed and manufactured a lightweight dosimetry instrument to be equipped with the head frame to LGK. It consists of a head phantom, a scintillator, a CCD camera and a step motor. The 10×10 cm2 sheet of Gd2O3;Tb phosphor or Gafchromic EBT3 film was located at the center of the 16 cm diameter hemispherical PMMA, the head phantom. The additional backscatter compensating material of 1 cm thick PMMA plate was placed downstream of the phosphor sheet. The backscatter plate was transparent for scintillation lights to reach the CCD camera with 1200×1200 pixels by 5.2 um pitch. With This equipment, 300 images with 0.2 mm of slice gap were acquired under three collimator setups (4mm, 8mm and 16mm), respectively. The 2D projected doses from 3D distributions were compared with the exposured film dose. Results: As all doses normalized by the maximum dose value in 16 mm setup, the relative differences between the equipment dose and film dose were 0.2% for 4mm collimator and 0.5% for 8mm. The acquisition of 300 images by the equipment took less than 3 minutes. Conclusion: The new equipment was verified to be a good substitute to radiochromic film, with which required more time and resources. Especially, the new methods was considered to provide much convenient and faster solution in the 3D dose acquisition for LGK.

  8. Dosimetry study for a new in vivo X-ray fluorescence (XRF) bone lead measurement system

    NASA Astrophysics Data System (ADS)

    Nie, Huiling; Chettle, David; Luo, Liqiang; O'Meara, Joanne

    2007-10-01

    A new 109Cd γ-ray induced bone lead measurement system has been developed to reduce the minimum detectable limit (MDL) of the system. The system consists of four 16 mm diameter detectors. It requires a stronger source compared to the "conventional" system. A dosimetry study has been performed to estimate the dose delivered by this system. The study was carried out by using human-equivalent phantoms. Three sets of phantoms were made to estimate the dose delivered to three age groups: 5-year old, 10-year old and adults. Three approaches have been applied to evaluate the dose: calculations, Monte Carlo (MC) simulations, and experiments. Experimental results and analytical calculations were used to validate MC simulation. The experiments were performed by placing Panasonic UD-803AS TLDs at different places in phantoms that representing different organs. Due to the difficulty of obtaining the organ dose and the whole body dose solely by experiments and traditional calculations, the equivalent dose and effective dose were calculated by MC simulations. The result showed that the doses delivered to the organs other than the targeted lower leg are negligibly small. The total effective doses to the three age groups are 8.45/9.37 μSv (female/male), 4.20 μSv, and 0.26 μSv for 5-year old, 10-year old and adult, respectively. An approval to conduct human measurements on this system has been received from the Research Ethics Board based on this research.

  9. An evaluation of the Panasonic model UD513AC-1 Thermoluminescence Dosimetry system

    SciTech Connect

    Durrer, R.E. Jr.

    1991-12-01

    An evaluation of the Panasonic UD513AC-1 Thermoluminescence Dosimetry system was performed to determine the system`s capabilities as a general purpose thermoluminescence dosimeter measuring device. The tests that were performed included a critique of the user`s manual, delimitation of the operating parameters, the quality of construction, and an evaluation of the features that were unique to this system. The UD513AC-1 was found to be an adequate measuring device for most dosimetric applications. It was not well suited for experimental work with thermoluminescence materials due to a low sensitivity displayed by the photomultiplier tube to commonly used materials. The system was well constructed and did not suffer hardware failure during this research. Major attributes of the UD513AC-1 were automatic data storage, highly reproducible heating ramps, an excellent infrared light filter and a unique feature to a single phosphor unit, a dose determination function. Negative aspects of the system included a limited data manipulation capability within the controlling program, a poorly written user`s manual, inadequate sensitivity on the part of the photomultiplier tube, and insufficient capability to adjust the hot N{sub 2} gas flow to desired levels.

  10. Commissioning and benchmarking a 3D dosimetry system for clinical use

    PubMed Central

    Thomas, Andrew; Newton, Joseph; Adamovics, John; Oldham, Mark

    2011-01-01

    Purpose: A 3D dosimetry system is described which consists of two parts: a radiochromic plastic dosimeter PRESAGE® (which responds to absorbed dose with a linear change in optical-density) and the Duke large-field-of-view optical-CT scanner (DLOS). The DLOS∕PRESAGE system has recently been commissioned and benchmarked for clinical use and, in particular, for verification and commissioning of complex radiation treatments. Methods: DLOS commissioning involved determining the dynamic range, spatial resolution, noise, temporal, and other characteristics of the light source and imaging components. Benchmarking tests were performed on the combined DLOS∕PRESAGE system to establish baseline dosimetric performance. The tests consisted of delivering simple radiation treatments to PRESAGE dosimeters, and comparing the measured 3D relative dose distributions with the known gold standard. The gold standard distribution was obtained from machine beam-data or the treatment planning system (TPS). All studies used standardized procedures to ensure consistency. Results: For commissioning, isotropic spatial resolution was submillimeter (MTF > 0.5 for frequencies of 1.5 lp∕mm) and the dynamic range was ∼60 dB. Flood field uniformity was within 10% and stable after 45 min of warm-up. Stray-light is small, due to telecentricity, but even the residual can be removed through deconvolution by a point-spread-function. For benchmarking, the mean 3D passing NDD (normalized dose distribution) rate (3%, 3mm, 5% dose threshold) over the benchmark data sets was 97.3% ± 0.6% (range 96%–98%), which is on par with other planar dosimeters used in external beam radiation therapy indicating excellent agreement. Noise was low at <2% of maximum dose (4–12 Gy) for 2 mm reconstructions. The telecentric design was critical to enabling fast imaging with minimal stray-light artifacts. Conclusions: This work presents the first comprehensive benchmarking of a 3D dosimetry system for

  11. Computational dosimetry

    SciTech Connect

    Siebert, B.R.L.; Thomas, R.H.

    1996-01-01

    The paper presents a definition of the term ``Computational Dosimetry`` that is interpreted as the sub-discipline of computational physics which is devoted to radiation metrology. It is shown that computational dosimetry is more than a mere collection of computational methods. Computational simulations directed at basic understanding and modelling are important tools provided by computational dosimetry, while another very important application is the support that it can give to the design, optimization and analysis of experiments. However, the primary task of computational dosimetry is to reduce the variance in the determination of absorbed dose (and its related quantities), for example in the disciplines of radiological protection and radiation therapy. In this paper emphasis is given to the discussion of potential pitfalls in the applications of computational dosimetry and recommendations are given for their avoidance. The need for comparison of calculated and experimental data whenever possible is strongly stressed.

  12. Individual Dose Calculations with Use of the Revised Techa River Dosimetry System TRDS-2009D

    SciTech Connect

    Degteva, M. O.; Shagina, N. B.; Tolstykh, E. I.; Vorobiova, M. I.; Anspaugh, L. R.; Napier, Bruce A.

    2009-10-23

    An updated deterministic version of the Techa River Dosimetry System (TRDS-2009D) has been developed to estimate individual doses from external exposure and intake of radionuclides for residents living on the Techa River contaminated as a result of radioactive releases from the Mayak plutonium facility in 1949–1956. The TRDS-2009D is designed as a flexible system that uses, depending on the input data for an individual, various elements of system databases to provide the dosimetric variables requested by the user. Several phases are included in the computation schedule. The first phase includes calculations with use of a common protocol for all cohort members based on village-average-intake functions and external dose rates; individual data on age, gender and history of residence are included in the first phase. This phase results in dose estimates similar to those obtained with system TRDS-2000 used previously to derive risks of health effects in the Techa River Cohort. The second phase includes refinement of individual internal doses for those persons who have had body-burden measurements or exposure parameters specific to the household where he/she lived on the Techa River. The third phase includes summation of individual doses from environmental exposure and from radiological examinations. The results of TRDS-2009D dose calculations have demonstrated for the ETRC members on average a moderate increase in RBM dose estimates (34%) and a minor increase (5%) in estimates of stomach dose. The calculations for the members of the ETROC indicated similar small changes for stomach, but significant increase in RBM doses (400%). Individual-dose assessments performed with use of TRDS-2009D have been provided to epidemiologists for exploratory risk analysis in the ETRC and ETROC. These data provide an opportunity to evaluate the possible impact on radiogenic risk of such factors as confounding exposure (environmental and medical), changes in the Techa River source

  13. Quality control and patient dosimetry in digital radiology. On line system: new features and transportability.

    PubMed

    Vano, E; Ten, J I; Fernandez, J M; Prieto, C; Ordiales, J M; Martinez, D

    2008-01-01

    New features have been added to a system (QCONLINE) for auditing patient dosimetric and technical parameters 'on line', working on a digital radiology department and using the information contained in the DICOM header of some modalities. The audit of other parameters than patient doses have been included, setting alarm conditions to alert on malfunction of the X-ray system or bad operation modes, in addition to the evaluation of patient doses. A new module to analyse, collect and process the relevant information transferred by the modality performed procedure step (MPPS) service has been launched. Several examples with the exploitation of the new features are presented. The transportability of the system has been tested in two remote hospitals during several months. The new MPPS module has demonstrated to be a good tool to complement the information existing in the DICOM header. The system allows to help in the optimisation of digital radiology departments managing patient dosimetry and procedure data in real time. PMID:18283057

  14. Use of accelerator mass spectrometry in the dosimetry of Hiroshima neutrons

    NASA Astrophysics Data System (ADS)

    Straume, T.; Finkel, R. C.; Eddy, D.; Kubik, P. W.; Gove, H. E.; Sharma, P.; Fujita, S.; Hoshi, M.

    1990-12-01

    A substantial discrepancy exists between the measured values for thermal neutron activation and the values calculated using the new A-bomb dosimetry system, DS86. As part of a joint US-Japan effort aimed at resolving this discrepancy, we have shown that 36Cl/Cl in mineral samples (i.e., concrete, granite, tiles) can be measured with sufficient precision using accelerator mass spectrometry (AMS) to quantify the very low thermal neutron activation levels at distances between 1000 and 2000 m from the hypocenter in Hiroshima. Our initial measurement results show that activation of Cl by the bomb neutrons disagree with calculations based on the new DS86 dosimetry system (measurements of 36Cl at 1450 m from the hypocenter indicate thermal neutron activation that is ˜15 times higher than obtained from DS86 calculations; discrepancies are even larger at 1606 m). This is a preliminary report of work in progress. The principal objectives of this work are to reconstruct the thermal neutron fluence as a function of distance from the hypocenters in both Hiroshima and Nagasaki using 36Cl/Cl and obtain information about fast neutron fluence.

  15. Evaluation of the US Army DT-236 battlefield personnel dosimetry system

    SciTech Connect

    Swaja, R.E.; Oyan, R.; Sims, C.S.; Dooley, M.A.

    1986-06-01

    Performance characteristics of the US Army DT-236 battlefield personnel dosimetry system were evaluated using the Health Physics Research Reactor at Oak Ridge National Laboratory. The DT-236 dosimeter is designed to measure total (neutron plus gamma) radiation dose using a radiophotoluminescent (RPL) detector for gamma rays and a silicon diode for fast neutrons. Areas considered in this evaluation included preirradiation dose indication; accuracy and precision of total, gamma, and neutron dose measurements; fading; angular response; temperature dependence; and relative dosimeter response in air and on various body locations. Experimental results for a variety of radiation fields and dose levels indicate that the existing system overestimates total, neutron, and gamma radiation doses in air by about 20 to 60% relative to reference values. Associated measurement precisions were about +-5% of the means for doses above approximately 0.5 Gy. Fading characteristics, angular dependence, and temperature dependence of the RPL and diode systems were consistent with results expected based on detector characteristics and previous performance studies. Recommendations to improve existing reader performance and measurement accuracy are also presented.

  16. Patient dosimetry and image quality in digital radiology from online audit of the X-ray system.

    PubMed

    Vano, E; Fernandez, J M; Ten, J I; Gonzalez, L; Guibelalde, E; Prieto, C

    2005-01-01

    The present work describes an online patient dosimetry and an image quality system in digital radiology. For the patient dosimetry audit, current mean values of entrance surface dose (ESD) were compared with local and national reference values (RVs) for the specific examination type evaluated. Mean values exceeding the RV trigger an alarm signal and then an evaluation of the technical parameters, operational practice and image quality was begun, using data available in the DICOM header to derive any abnormal settings or performance to obtain the image. The X-ray tube output for different kVp values is measured periodically, to allow for the automatic calculation of ESD. The system allows also for image audit, linking the dose imparted, the image quality and the alarm condition, if produced. Results and the benefits derived from this online quality control are discussed here. PMID:16461529

  17. Transition from Paris dosimetry system to 3D image-guided planning in interstitial breast brachytherapy

    PubMed Central

    Wronczewska, Anna; Kabacińska, Renata; Makarewicz, Roman

    2015-01-01

    Purpose The purpose of this study is to evaluate our first experience with 3D image-guided breast brachytherapy and to compare dose distribution parameters between Paris dosimetry system (PDS) and image-based plans. Material and methods First 49 breast cancer patients treated with 3D high-dose-rate interstitial brachytherapy as a boost were selected for the study. Every patient underwent computed tomography, and the planning target volume (PTV) and organs at risk (OAR) were outlined. Two treatment plans were created for every patient. First, based on a Paris dosimetry system (PDS), and the second one, imaged-based plan with graphical optimization (OPT). The reference isodose in PDS implants was 85%, whereas in OPT plans the isodose was chosen to obtain proper target coverage. Dose and volume parameters (D90, D100, V90, V100), doses at OARs, total reference air kerma (TRAK), and quality assurance parameters: dose nonuniformity ratio (DNR), dose homogeneity index (DHI), and conformity index (COIN) were used for a comparison of both plans. Results The mean number of catheters was 7 but the mean for 20 first patients was 5 and almost 9 for the next 29 patients. The mean value of prescribed isodose for OPT plans was 73%. The mean D90 was 88.2% and 105.8%, the D100 was 59.8% and 75.7%, the VPTV90 was 88.6% and 98.1%, the VPTV100 was 79.9% and 98.9%, and the TRAK was 0.00375 Gym–1 and 0.00439 Gym–1 for the PDS and OPT plans, respectively. The mean DNR was 0.29 and 0.42, the DHI was 0.71 and 0.58, and the COIN was 0.68 and 0.76, respectively. Conclusions The target coverage in image-guided plans (OPT) was significantly higher than in PDS plans but the dose homogeneity was worse. Also, the value of TRAK increased because of change of prescribing isodose. The learning curve slightly affected our results. PMID:26816505

  18. 36Cl and41Ca depth profiles in a Hiroshima granite stone and the Dosimetry System 1986

    NASA Astrophysics Data System (ADS)

    Rühm, W.; Kato, K.; Korschinek, G.; Morinaga, H.; Nolte, E.

    1992-06-01

    For the first time a depth profile of the radioisotope41Ca produced by neutrons from the atomic bomb explosion of Hiroshima was measured. The measurements were performed at the Munich Tandem Laboratory via accelerator mass spectrometry. The41Ca depth profile is part of the evaluation to determine the neutron spectrum of the A-bomb which is basis of the Dosimetry System 1986.

  19. A-bomb survivor dosimetry update

    SciTech Connect

    Loewe, W.E.

    1982-06-01

    A-bomb survivor data have been generally accepted as applicable. Also, the initial radiations have tended to be accepted as the dominant radiation source for all survivors. There was general acceptance of the essential reliability of both the biological effects data and the causative radiation dose values. There are considerations casting doubt on these acceptances, but very little quantification of th implied uncertainties has been attempted. The exception was A-bomb survivor dosimetry, where free-field kerma values for initial radiations were thought to be accurate to about 30%, and doses to individual survivors were treated as effectively error-free. In 1980, a major challenge to the accepted A-bomb survivor dosimetry was announced, and was quickly followed by a succession of explanations and displays showing the soundness of that challenge. In fact, a complete replacement set of free-field kerma values was provided which was suitable for use in constructing an entire new dosimetry for Hiroshima and Nagasaki. The new values showed many changes greater than the accepted 30% uncertainty. An approximate new dosimetry was indeed constructed, and used to convert existing leukemia cause-and-effect data from the old to the new dose values, by way of assessing the impact. (ERB)

  20. New dosimetry of atomic bomb radiations.

    PubMed

    Fry, R J; Sinclair, W K

    1987-10-10

    The reassessment of the radiation dosimetry from the Hiroshima and Nagasaki atomic bombs is almost complete. Since atomic bomb survivors provide a major source of data for estimates of risk of cancer induction by radiation the impact of the new dosimetry on risk estimates and radiation protection standards is important. The changes include an increase of about 20% in the estimated yield of the Hiroshima bomb and a reduction in the estimated doses from neutrons in both cities. The estimated neutron dose for Hiroshima is about 10% of the previous estimate. The neutron doses are now so small that direct estimates of neutron relative biological effectiveness may be precluded or be much more difficult. There is little change in most of the gamma ray organ doses because various changes in the new estimates tend to cancel each other out. The new estimate of the attenuation of the free-in-air kerma by the walls of the homes is about twice that used in the previous dosimetry. But the transmission of gamma radiation to the deep organs such as bone marrow is significantly greater than earlier estimates. Probably future risk estimates for radiogenic cancer will be somewhat higher because of both the new dosimetry and the new cancer mortality data. New risk estimates should be available in 1988. PMID:2889042

  1. An automated dosimetry system for testing whole-body ultraviolet phototherapy cabinets

    NASA Astrophysics Data System (ADS)

    Currie, G. D.; Evans, A. L.; Smith, D.; Martin, C. J.; McCalman, S.; Bilsland, D.

    2001-02-01

    A new technique is described for automated ultraviolet dosimetry within whole-body phototherapy cabinets. A dual-head detector system has been designed, permitting simultaneous assessment of irradiance levels and radiant intensities from individual lamps. One detector is used in combination with a diffuser/filter system for the measurement of irradiance and the other is mounted at the end of a slit collimator to provide a measurement which can be related to the radiant intensities of the individual lamps. These quantities are derived from 800 separate measurements made during rotation of the detector head around a 360° circle at a fixed height and position within the cabinet under remote computer software control. The device has advantages compared with standard techniques, enabling measurements to be made without the need for a person to be present in the cabinet. A full set of measurements is made with minimal switching of the power supply to the lamps. This simplifies the assessment and reduces the uncertainty from variation in output after the lamps are switched on. Variations in irradiance with orientation for the smaller phototherapy cabinets are clearly demonstrated. Plots of data from the collimated detector show peaks corresponding to the lamps and the surrounding reflectors. The plots enable failed lamps to be detected and peak values can be related to radiant intensities of individual lamps.

  2. Photodynamic therapy: development of a treatment and dosimetry system adapted to superficial tumors of the bladder

    NASA Astrophysics Data System (ADS)

    Lignon, Dominique; Jaboin, Y.; Wolf, D.; Meunier-Reynes, Anne; Guillemin, Francois H.

    1993-06-01

    Superficial tumors of the bladder or in situ carcinoma could be interesting indications of Photodynamic Therapy (PDT), since a total mutilating cystectomy could be avoided. The plurifocality of the lesions requires a treatment of the whole mucose; the quantity of light energy must be homogenous and sufficient to induce a therapeutic effect, still non toxic for normal tissues. We therefore developed a system of treatment and intravesical dosimetry control so that the operator can have precise information on the light repartition in the bladder in real time to enable him to optimize the positioning of the irradiation source. This intravesical device consists of twelve light sensors with optical fiber distributed symmetrically against the walls of the bladder; the emitting source is constituted of a scattering isotropic sphere. The signals emitted by the sensors are converted into tension. The acquisition part of the system values consists of two parts : an analogic part, the values are multiplexed on a same oscilloscope track to see in real time their evolution according to the position of the emitting source. The other part is constituted by the numeric acquisition of values for further analysis. We developed, from a mathematical modelisation of the bladder, a centering program of the diffusor that indicates its position in the bladder, as well as a cartography program where the bladder is re-built by interpolation with the different lighting levels.

  3. The 2002 dosimetry system (DS02) and available fluences for organ dose calculations.

    PubMed

    Egbert, Stephen D

    2012-03-01

    The A bomb dosimetry system (DS) calculates each survivor's organ doses. It does this by calculating the angular fluences incident on each survivor. These are used with humanoid phantom shielding calculations to estimate organ doses in 15 organs, 3-sized phantoms, 2 sexes and 2 postures at any orientation or distance to the bomb. The DS has been re-used and updated several times. Currently, efforts are being considered to include shielding for additional organs by adding additional phantoms. The DS has gone through a series of upgrades referred to as: DS84, DS86, DS86R, DS93, DS02. DS86 and DS02 were approved and installed at Radiation Effects Research Foundation. The system uses free-field energy-angular fluence from a discrete ordinate calculation coupled with Monte Carlo adjoint-shielding histories. This paper briefly discusses the adjoint Monte Carlo; combinatorial shield geometry for the phantom, house, factory, and terrain; modifications to use fictitious scattering in voxel phantoms; the adjoint source energy, angle and location distribution; 'leakage histories' and their optimisation for dose or fluence; doubly differential (energy-angle) coupling for single-, double-, or triple-shielding coupling; output of various components of dose and energy-angular fluences; survivor-specific inputs; organ dose uncertainty; and testing, benchmarking and extended applications. Also, approaches to add additional organ-shielding calculations to DS02 are discussed. PMID:21778157

  4. SU-E-I-86: Evaluation of the New RaySafe Unfors X2 Dosimetry System

    SciTech Connect

    Heintz, P; Chambers, G; Sandoval, D

    2014-06-01

    Purpose: To evaluate the new RaySafe Unfors X2 (X2) dosimetry system and compare it to the operation of the RaySafe Unfors Xi (Xi) and Radcal Accugold (RCAG) dosimetry systems. The comparison was done for the radiographic/fluoroscopic detectors, mammography detectors and the CT ionization chambers. Methods: This study used several R/F rooms, GE AMX4 portable x-ray unit, Siemens Biograph 16 slice CT scanner and a Hologic Dimensions mammography unit to evaluate the dosimetry systems. The three X2 detectors were compared to similar detectors of the older Xi and RCAG detectors under clinical conditions used for diagnostic medical physics testing. Measurements of kVp, HVL and exposure were made under identical conditions. Results: For radiography and fluoroscopy the three systems agreed to within +2 kVp in the 60 to 140 kVp range, HVL measurements agreed to within +2 mm Al and the exposures agreed to within +5%. The RCAG 6 cc ionization chamber measured at least 3% higher than the diode systems. The X2 R/F detector appeared to be transparent to the fluoroscopy AEC system. For exposures made using both the CT ACR dose phantoms, the X2 agreed to within +3% of the other two systems. For mammography measurements, the three systems agreed to within +0.4kVp (25-49 kVp range), HVL measurements agreed to within +0.05 mm Al and the exposures agreed to within +1% of the ionization chamber. Conclusion: The X2 system is a new version of the older Xi system. The system is faster, more robust, very easy to use, has a larger dynamic range, produced less errors and stores 1000 exposures. The measurements showed that the system performs well in the clinical environment and the X2 is within + 5% agreement of the other two calibrated systems.

  5. Scintillator-CCD camera system light output response to dosimetry parameters for proton beam range measurement

    NASA Astrophysics Data System (ADS)

    Daftari, Inder K.; Castaneda, Carlos M.; Essert, Timothy; Phillips, Theodore L.; Mishra, Kavita K.

    2012-09-01

    The purpose of this study is to investigate the luminescence light output response in a plastic scintillator irradiated by a 67.5 MeV proton beam using various dosimetry parameters. The relationship of the visible scintillator light with the beam current or dose rate, aperture size and the thickness of water in the water-column was studied. The images captured on a CCD camera system were used to determine optimal dosimetry parameters for measuring the range of a clinical proton beam. The method was developed as a simple quality assurance tool to measure the range of the proton beam and compare it to (a) measurements using two segmented ionization chambers and water column between them, and (b) with an ionization chamber (IC-18) measurements in water. We used a block of plastic scintillator that measured 5×5×5 cm3 to record visible light generated by a 67.5 MeV proton beam. A high-definition digital video camera Moticam 2300 connected to a PC via USB 2.0 communication channel was used to record images of scintillation luminescence. The brightness of the visible light was measured while changing beam current and aperture size. The results were analyzed to obtain the range and were compared with the Bragg peak measurements with an ionization chamber. The luminescence light from the scintillator increased linearly with the increase of proton beam current. The light output also increased linearly with aperture size. The relationship between the proton range in the scintillator and the thickness of the water column showed good linearity with a precision of 0.33 mm (SD) in proton range measurement. For the 67.5 MeV proton beam utilized, the optimal parameters for scintillator light output response were found to be 15 nA (16 Gy/min) and an aperture size of 15 mm with image integration time of 100 ms. The Bragg peak depth brightness distribution was compared with the depth dose distribution from ionization chamber measurements and good agreement was observed. The peak

  6. Characterization of a computed radiography system for external radiotherapy beam dosimetry.

    PubMed

    Aberle, Christoph; Kapsch, Ralf-Peter

    2016-06-01

    A commercial computed radiography (CR) system was studied as an option for quantitative dosimetry quality assurance of external radiotherapy beams. Following the examination of influencing quantities, practical measurement procedures are discussed. Corrections were derived for image fading, an observed long-term response drift and the image length scale, which was found to be off by up to 2-3%. It is known that energy dependence is important for CR measurements. Therefore, signal-to-dose calibration curves and the energy dependence of the response were studied extensively using multiple photon and electron beam qualities. Doses which yield the same signal vary by up to tens of percent for different beam qualities. Results on the directional response of the plates are presented. It was found that rotations of up to 30° to 40° relative to perpendicular irradiation yield no significant change in response. Finally, the homogeneity of the response over the measurement region was studied for electrons and photons and a correction method is described. In summary, relative dose measurements with uncertainties of a few percent are feasible in regions of constant beam energy. PMID:27163755

  7. The Techa River dosimetry system: methods for the reconstruction of internal dose.

    PubMed

    Degteva, M O; Kozheurov, V P; Tolstykh, E I; Vorobiova, M I; Anspaugh, L R; Napier, B A; Kovtun, A N

    2000-07-01

    The Mayak Production Association (MPA) was the first facility in the former Soviet Union for the production of plutonium. Significant worker and population exposures occurred as a result of failures in the technological processes in the late 1940's and early 1950's. Residents of many villages downstream on the Techa River were exposed via a variety of pathways; the more significant included drinking of water from the river and external gamma exposure due to proximity to contaminated bottom sediment and shoreline. After the extent of the major contamination of the Techa River became known, several villages on the upper part of the Techa River were evacuated. Organ doses are being reconstructed on the basis of derivation of an historical source term and a simple river model used to simulate the transport of radionuclides downstream and their retention on sediments; measurements of 90Sr content in teeth and the whole body of half of the members of the cohort; and development of the "Techa River Dosimetry System" for computation of the doses. PMID:10855775

  8. Characterization of a computed radiography system for external radiotherapy beam dosimetry

    NASA Astrophysics Data System (ADS)

    Aberle, Christoph; Kapsch, Ralf-Peter

    2016-06-01

    A commercial computed radiography (CR) system was studied as an option for quantitative dosimetry quality assurance of external radiotherapy beams. Following the examination of influencing quantities, practical measurement procedures are discussed. Corrections were derived for image fading, an observed long-term response drift and the image length scale, which was found to be off by up to 2–3%. It is known that energy dependence is important for CR measurements. Therefore, signal-to-dose calibration curves and the energy dependence of the response were studied extensively using multiple photon and electron beam qualities. Doses which yield the same signal vary by up to tens of percent for different beam qualities. Results on the directional response of the plates are presented. It was found that rotations of up to 30° to 40° relative to perpendicular irradiation yield no significant change in response. Finally, the homogeneity of the response over the measurement region was studied for electrons and photons and a correction method is described. In summary, relative dose measurements with uncertainties of a few percent are feasible in regions of constant beam energy.

  9. The Techa River dosimetry system: Methods for the reconstruction of internal dose

    SciTech Connect

    Degteva, M.O.; Kozheurov, V.P.; Tolstykh, E.I.; Vorobiova, M.I.; Anspaugh, L.R.; Napier, B.A.; Kovtun, A.N.

    2000-07-01

    The Mayak Production Association (MPA) was the first facility in the former Soviet Union for the production of plutonium. Significant worker and population exposures occurred as a result of failures in the technological processes in the late 1940's and early 1950's. Residents of many villages downstream on the Techa River were exposed via a variety of pathways; the more significant included drinking of water from the river and external gamma exposure due to proximity to contaminated bottom sediment and shoreline. After the extent of the major contamination of the Techa River became known, several villages on the upper part of the Techa River were evacuated. Organ doses are being reconstructed on the basis of derivation of an historical source term and a simple river model used to simulate the transport of radionuclides downstream and their retention on sediments; measurements of {sup 90}Sr content in teeth and the whole body of half of the members of the cohort; and development of the Techa River Dosimetry System for computation of the doses.

  10. Epid Dosimetry

    NASA Astrophysics Data System (ADS)

    Greer, Peter B.; Vial, Philip

    2011-05-01

    Electronic portal imaging devices (EPIDs) were introduced originally for patient position verification. The idea of using EPIDs for dosimetry was realised in the 1980s. Little was published on the topic until the mid 1990's, when the interest in EPIDs for dosimetry increased rapidly and continues to grow. The increasing research on EPID dosimetry coincided with the introduction of intensity modulated radiation therapy (IMRT). EPIDs are well suited to IMRT dosimetry because they are high resolution, two-dimensional (2D) digital detectors. They are also pre-existing on almost all modern linear accelerators. They generally show a linear response to increasing dose. Different types of EPIDs have been clinically implemented, and these have been described in several review papers. The current generation of commercially available EPIDs are indirect detection active matrix flat panel imagers, also known as amorphous silicon (a-Si) EPIDs. Disadvantages of a-Si EPIDs for dosimetry include non-water equivalent construction materials, and the energy sensitivity and optical scatter of the phosphor scintillators used to create optical signal from the megavoltage beam. This report discusses current knowledge regarding a-Si EPIDs for dosimetry.

  11. Epid Dosimetry

    SciTech Connect

    Greer, Peter B.; Vial, Philip

    2011-05-05

    Electronic portal imaging devices (EPIDs) were introduced originally for patient position verification. The idea of using EPIDs for dosimetry was realised in the 1980s. Little was published on the topic until the mid 1990's, when the interest in EPIDs for dosimetry increased rapidly and continues to grow. The increasing research on EPID dosimetry coincided with the introduction of intensity modulated radiation therapy (IMRT). EPIDs are well suited to IMRT dosimetry because they are high resolution, two-dimensional (2D) digital detectors. They are also pre-existing on almost all modern linear accelerators. They generally show a linear response to increasing dose. Different types of EPIDs have been clinically implemented, and these have been described in several review papers. The current generation of commercially available EPIDs are indirect detection active matrix flat panel imagers, also known as amorphous silicon (a-Si) EPIDs. Disadvantages of a-Si EPIDs for dosimetry include non-water equivalent construction materials, and the energy sensitivity and optical scatter of the phosphor scintillators used to create optical signal from the megavoltage beam. This report discusses current knowledge regarding a-Si EPIDs for dosimetry.

  12. Use of novel fibre-coupled radioluminescence and RADPOS dosimetry systems for total scatter factor measurements in small fields

    NASA Astrophysics Data System (ADS)

    Ploquin, N.; Kertzscher, G.; Vandervoort, E.; Cygler, J. E.; Andersen, C. E.; Francescon, P.

    2015-01-01

    A dosimetry system based on Al2O3:C radioluminescence (RL), and RADPOS, a novel 4D dosimetry system using microMOSFETs, were used to measure total scatter factors, ≤ft({{S}c,p}\\right)\\text{det}{{f\\text{clin}}}, for the CyberKnife robotic radiosugery system. New Monte Carlo calculated correction factors are presented and applied for the RL detector response for the 5, 7.5 and 10 mm collimators in order to correct for the detector geometry and increased photoelectric cross section of Al2O3:C relative to water. For comparison, measurements were also carried out using a micro MOSFET, PTW60012 diode and GAFCHROMIC® film (EBT and EBT2). Uncorrected ≤ft({{S}c,p}\\right)\\text{det}{{f\\text{clin}}}, were obtained by taking the ratio of the detector response for each collimator to that for the 60 mm diameter reference field. Published Monte Carlo calculated correction factors were applied to the RADPOS, microMOSFET and diode detector measurements to yield corrected field factors, Ω {{Q\\text{clin}},{{Q}\\text{msr}}}{{f\\text{clin}},{{f}\\text{msr}}}, following the terminology of a recent formalism introduced for small and composite field relative dosimetry. With corrections, the RL measured Ω {{Q\\text{clin}},{{Q}\\text{msr}}}{{f\\text{clin}},{{f}\\text{msr}}}, were 0.656  ±  0.002, 0.815  ±  0.002 and 0.865  ±  0.003 for the 5, 7.5 and 10 mm collimators, respectively. This was in good agreement with RADPOS corrected field factors of 0.650  ±  0.010, 0.816  ±  0.024 and 0.867  ±  0.010 for the 5, 7.5 and 10 mm collimators, respectively. Both RL and RADPOS total scatter factors agreed within approximately two standard deviations of the GAFCHROMIC film values (average of EBT and EBT2) of 0.640  ±  0.006, 0.806  ±  0.007 and 0.859  ±  0.09. Corrected total scatter factors for all dosimetry systems agreed within one standard deviation for collimator sizes 10-60 mm. Our study suggests that the micro

  13. Overview of the nuclear data related to the Hiroshima Dosimetry Discrepancy

    SciTech Connect

    Pace, J.V. III

    1994-09-01

    Nearly half a century ago the first atomic bomb was dropped on Hiroshima; several days later, a second atomic bomb was dropped on Nagasaki. Japan immediately initiated a study of all aspects of the effects of the bombings. Thus the initial effort was begun to estimate the overall risks of radiation effects in man due to nuclear detonations. By the 1950s, Japan and the United States had produced several studies that reported on the elevated risk of cancer. In 1957 the first dose estimates for survivors were designated as Tentative 1957 Doses or T57D. In 1965 a revised dosimetry system was adopted to replace T57D, and the dose estimates were designated as Tentative 1965 Doses or T65D. The current evaluation, known as Dosimetry System 1986 or DS86, was the result of a presentation by H.H. Rossi in 1976 to the US National Council on Radiation Protection and Measurements (NCRP). In the presentation, Rossi recommended that the NCRP reduce its permissible neutron dose limits by an order of magnitude. A direct result of this drastic proposal was a new dosimetry reevaluation effort. After the calculations were made and compared to the measurements, it was found that the thermal data at both cities was in disagreement. The state-of-the-art radiation transport calculational codes require evaluated neutron and gamma-ray reaction cross-section data (which themselves were determined empirically or theoretically) to complete the cycle and calculate the measured data. This paper will review some of the more important in situ measured data taken over the last forty-five years, the measurement and reevaluation of some of the major cross sections required for the calculations, and the effort to agreement through calculations with some of the in situ measurements.

  14. Radon concentrations in residential housing in Hiroshima and Nagasaki

    SciTech Connect

    Yonehara, Hidenori; Aoyama, Takashi; Radford, E.P.

    1995-05-01

    A measurement of indoor radon ({sup 222}Rn) concentrations in Hiroshima and Nagasaki was carried out to assess the variability of exposure expected among atomic bomb survivors. Two hundred dwellings, mostly belonging to members of the fixed cohort of atomic bomb survivors under study by the Radiation Effects Research Foundations, were selected for this measurement. The geometric mean values of the radon concentrations for 100 dwellings in Hiroshima and 99 dwellings in Nagasaki measured by Track-Etcho Type SF detectors were 56.8 Bq m{sup {minus}3} and 28.5 Bq m{sup {minus}3}, respectively. No statistically significant difference was observed between lung cancer mortalities in the low-dose range in the two cities. However, apparent values of the mortality rate for low dose range in Hiroshima are consistently greater than those in Nagasaki. The exposure to radon and its progeny and the atomic bomb radiation effect might have some cooperative effects on the lung cancer incidence.

  15. Effect of recent changes in atomic bomb survivor dosimetry on cancer mortality risk estimates.

    PubMed

    Preston, Dale L; Pierce, Donald A; Shimizu, Yukiko; Cullings, Harry M; Fujita, Shoichiro; Funamoto, Sachiyo; Kodama, Kazunori

    2004-10-01

    The Radiation Effects Research Foundation has recently implemented a new dosimetry system, DS02, to replace the previous system, DS86. This paper assesses the effect of the change on risk estimates for radiation-related solid cancer and leukemia mortality. The changes in dose estimates were smaller than many had anticipated, with the primary systematic change being an increase of about 10% in gamma-ray estimates for both cities. In particular, an anticipated large increase of the neutron component in Hiroshima for low-dose survivors did not materialize. However, DS02 improves on DS86 in many details, including the specifics of the radiation released by the bombs and the effects of shielding by structures and terrain. The data used here extend the last reported follow-up for solid cancers by 3 years, with a total of 10,085 deaths, and extends the follow-up for leukemia by 10 years, with a total of 296 deaths. For both solid cancer and leukemia, estimated age-time patterns and sex difference are virtually unchanged by the dosimetry revision. The estimates of solid-cancer radiation risk per sievert and the curvilinear dose response for leukemia are both decreased by about 8% by the dosimetry revision, due to the increase in the gamma-ray dose estimates. The apparent shape of the dose response is virtually unchanged by the dosimetry revision, but for solid cancers, the additional 3 years of follow-up has some effect. In particular, there is for the first time a statistically significant upward curvature for solid cancer on the restricted dose range 0-2 Sv. However, the low-dose slope of a linear-quadratic fit to that dose range should probably not be relied on for risk estimation, since that is substantially smaller than the linear slopes on ranges 0-1 Sv, 0-0.5 Sv, and 0- 0.25 Sv. Although it was anticipated that the new dosimetry system might reduce some apparent dose overestimates for Nagasaki factory workers, this did not materialize, and factory workers have

  16. Dynamic dosimetry and edema detection in prostate brachytherapy: a complete system

    NASA Astrophysics Data System (ADS)

    Jain, A.; Deguet, A.; Iordachita, I.; Chintalapani, G.; Blevins, J.; Le, Y.; Armour, E.; Burdette, C.; Song, D.; Fichtinger, G.

    2008-03-01

    Purpose: Brachytherapy (radioactive seed insertion) has emerged as one of the most effective treatment options for patients with prostate cancer, with the added benefit of a convenient outpatient procedure. The main limitation in contemporary brachytherapy is faulty seed placement, predominantly due to the presence of intra-operative edema (tissue expansion). Though currently not available, the capability to intra-operatively monitor the seed distribution, can make a significant improvement in cancer control. We present such a system here. Methods: Intra-operative measurement of edema in prostate brachytherapy requires localization of inserted radioactive seeds relative to the prostate. Seeds were reconstructed using a typical non-isocentric C-arm, and exported to a commercial brachytherapy delivery system. Technical obstacles for 3D reconstruction on a non-isocentric C-arm include pose-dependent C-arm calibration; distortion correction; pose estimation of C-arm images; seed reconstruction; and C-arm to TRUS registration. Results: In precision-machined hard phantoms with 40-100 seeds and soft tissue phantoms with 45-87 seeds, we correctly reconstructed the seed implant shape with an average 3D precision of 0.35 mm and 0.24 mm, respectively. In a DoD Phase-1 clinical trial on 6 patients with 48-82 planned seeds, we achieved intra-operative monitoring of seed distribution and dosimetry, correcting for dose inhomogeneities by inserting an average of 4.17 (1-9) additional seeds. Additionally, in each patient, the system automatically detected intra-operative seed migration induced due to edema (mean 3.84 mm, STD 2.13 mm, Max 16.19 mm). Conclusions: The proposed system is the first of a kind that makes intra-operative detection of edema (and subsequent re-optimization) possible on any typical non-isocentric C-arm, at negligible additional cost to the existing clinical installation. It achieves a significantly more homogeneous seed distribution, and has the potential to

  17. An Absorbed-Dose/Dose-Rate Dependence for the Alanine-EPR Dosimetry System and Its Implications in High-Dose Ionizing Radiation Metrology

    PubMed Central

    Desrosiers, M. F.; Puhl, J. M.; Cooper, S. L.

    2008-01-01

    NIST developed the alanine dosimetry system in the early 1990s to replace radiochromic dye film dosimeters. Later in the decade the alanine system was firmly established as a transfer service for high-dose radiation dosimetry and an integral part of the internal calibration scheme supporting these services. Over the course of the last decade, routine monitoring of the system revealed a small but significant observation that, after examination, led to the characterization of a previously unknown absorbed-dose-dependent, dose-rate effect for the alanine system. Though the potential impact of this effect is anticipated to be extremely limited for NIST’s customer-based transfer dosimetry service, much greater implications may be realized for international measurement comparisons between National Measurement Institutes. PMID:27096113

  18. (Biological dosimetry)

    SciTech Connect

    Preston, R.J.

    1990-12-17

    The traveler attended the 1st International Conference on Biological Dosimetry in Madrid, Spain. This conference was organized to provide information to a general audience of biologists, physicists, radiotherapists, industrial hygiene personnel and individuals from related fields on the current ability of cytogenetic analysis to provide estimates of radiation dose in cases of occupational or environmental exposure. There is a growing interest in Spain in biological dosimetry because of the increased use of radiation sources for medical and occupational uses, and with this the anticipated and actual increase in numbers of overexposure. The traveler delivered the introductory lecture on Biological Dosimetry: Mechanistic Concepts'' that was intended to provide a framework by which the more applied lectures could be interpreted in a mechanistic way. A second component of the trip was to provide advice with regard to several recent cases of overexposure that had been or were being assessed by the Radiopathology and Radiotherapy Department of the Hospital General Gregorio Maranon'' in Madrid. The traveler had provided information on several of these, and had analyzed cells from some exposed or purportedly exposed individuals. The members of the biological dosimetry group were referred to individuals at REACTS at Oak Ridge Associated Universities for advice on follow-up treatment.

  19. Development of an improved dosimetry system for the workers at the Mayak Production Association

    SciTech Connect

    Khokhryakov, V.; Suslova, K.; Aladova, E.; Vasilenko, E.; Miller, S.C.; Slaughter, D.M.; Krahenbuhl, M.P.

    2000-07-01

    Databases are being created that contain verified and updated dosimetry and worker history information for workers at the Mayak Production Association. many workers had significant external and internal exposures, particularly during the early years (1948--1952) of operation. These dosimetric and worker history data are to be used in companion epidemiology studies of stochastic and deterministic effects. The database contains both external and internal dose information and is being constructed from other databases that include radiochemical analyses of tissues, bioassay data, air sampling data, while body counting data, and occupational and worker histories. The procedures, models, methods, and operational uncertainties will be documented and included in the database, technical reports, and publications. The cohort of the stochastic epidemiological study is expected to include about 19,000 persons while the cohort for the deterministic epidemiological study is expected to include about 600 persons. For external dosimetry, workplace gamma, beta, and neutron doses are being reconstructed. The models used for this incorporate issues such as known isotopes, composition, shielding, further analysis of film bandage sensitivities, and records of direct measurements. Organ doses from external exposures are also being calculated. Methods for calculating dose uncertainties are being developed. For internal dosimetry, the organ doses have been calculated using the established FIB-1 biokinetic model. A new biokinetic model is being developed that includes more information of the solubility and biokinetics of the different chemical forms and particulate sizes of plutonium that were in the workplace. In addition, updated worker histories will be sued to estimate doses to some workers where direct measurements were not made. A rigorous quality control procedure is being implemented to ensure that the correct dosimetry data is entering the various databases being used by the

  20. Toward acquiring comprehensive radiosurgery field commissioning data using the PRESAGE®/optical-CT 3D dosimetry system

    PubMed Central

    Clift, Corey; Thomas, Andrew; Adamovics, John; Chang, Zheng; Das, Indra; Oldham, Mark

    2010-01-01

    Achieving accurate small field dosimetry is challenging. This study investigates the utility of a radiochromic plastic PRESAGE® read with optical-CT for the acquisition of radiosurgery field commissioning data from a Novalis Tx system with a high-definition multileaf collimator (HDMLC). Total scatter factors (Sc, p), beam profiles, and penumbrae were measured for five different radiosurgery fields (5, 10, 20, 30 and 40 mm) using a commercially available optical-CT scanner (OCTOPUS, MGS Research). The percent depth dose (PDD), beam profile and penumbra of the 10 mm field were also measured using a higher resolution in-house prototype CCD-based scanner. Gafchromic EBT® film was used for independent verification. Measurements of Sc, p made with PRESAGE® and film agreed with mini-ion chamber commissioning data to within 4% for every field (range 0.2–3.6% for PRESAGE®, and 1.6–3.6% for EBT). PDD, beam profile and penumbra measurements made with the two PRESAGE®/optical-CT systems and film showed good agreement with the high-resolution diode commissioning measurements with a competitive resolution (0.5 mm pixels). The in-house prototype optical-CT scanner allowed much finer resolution compared with previous applications of PRESAGE®. The advantages of the PRESAGE® system for small field dosimetry include 3D measurements, negligible volume averaging, directional insensitivity, an absence of beam perturbations, energy and dose rate independence. PMID:20134082

  1. Tactical gamma and fast neutron dosimetry with leuko dye optical waveguides. Conference paper

    SciTech Connect

    Kronenberg, S.

    1982-06-18

    Ionizing radiation-induced changes in the refractive index of radiochromic dye solution results in a novel dosimetry system with a very wide dynamic range. This approach is adaptable to personnel dosimetry and to Army tactical dosimetry.

  2. System for interstitial photodynamic therapy with online dosimetry: first clinical experiences of prostate cancer

    NASA Astrophysics Data System (ADS)

    Swartling, Johannes; Axelsson, Johan; Ahlgren, Göran; Kälkner, Karl Mikael; Nilsson, Sten; Svanberg, Sune; Svanberg, Katarina; Andersson-Engels, Stefan

    2010-09-01

    The first results from a clinical study for Temoporfin-mediated photodynamic therapy (PDT) of low-grade (T1c) primary prostate cancer using online dosimetry are presented. Dosimetric feedback in real time was applied, for the first time to our knowledge, in interstitial photodynamic therapy. The dosimetry software IDOSE provided dose plans, including optical fiber positions and light doses based on 3-D tissue models generated from ultrasound images. Tissue optical property measurements were obtained using the same fibers used for light delivery. Measurements were taken before, during, and after the treatment session. On the basis of these real-time measured optical properties, the light-dose plan was recalculated. The aim of the treatment was to ablate the entire prostate while minimizing exposure to surrounding organs. The results indicate that online dosimetry based on real-time tissue optical property measurements enabled the light dose to be adapted and optimized. However, histopathological analysis of tissue biopsies taken six months post-PDT treatment showed there were still residual viable cancer cells present in the prostate tissue sections. The authors propose that the incomplete treatment of the prostate tissue could be due to a too low light threshold dose, which was set to 5 J/cm2.

  3. Correcting scan-to-scan response variability for a radiochromic film-based reference dosimetry system

    SciTech Connect

    Lewis, David; Devic, Slobodan

    2015-10-15

    Purpose: In radiochromic film dosimetry systems, measurements are usually obtained from film images acquired on a CCD-based flatbed scanner. The authors investigated factors affecting scan-to-scan response variability leading to increased dose measurement uncertainty. Methods: The authors used flatbed document scanners to repetitively scan EBT3 radiochromic films exposed to doses 0–1000 cGy, together with three neutral density filters and three blue optical filters. Scanning was performed under two conditions: scanner lid closed and scanner lid opened/closed between scans. The authors also placed a scanner in a cold room at 9 °C and later in a room at 22 °C and scanned EBT3 films to explore temperature effects. Finally, the authors investigated the effect of altering the distance between the film and the scanner’s light source. Results: Using a measurement protocol to isolate the contribution of the CCD and electronic circuitry of the scanners, the authors found that the standard deviation of response measurements for the EBT3 film model was about 0.17% for one scanner and 0.09% for the second. When the lid of the first scanner was opened and closed between scans, the average scan-to-scan difference of responses increased from 0.12% to 0.27%. Increasing the sample temperature during scanning changed the RGB response values by about −0.17, −0.14, and −0.05%/°C, respectively. Reducing the film-to-light source distance increased the RBG response values about 1.1, 1.3, and 1.4%/mm, respectively. The authors observed that films and film samples were often not flat with some areas up to 8 mm away from the scanner’s glass window. Conclusions: In the absence of measures to deal with the response irregularities, each factor the authors investigated could lead to dose uncertainty >2%. Those factors related to the film-to-light source distance could be particularly impactful since the authors observed many instances where the curl of film samples had the

  4. Neutron personnel dosimetry

    SciTech Connect

    Griffith, R.V.

    1981-06-16

    The current state-of-the-art in neutron personnel dosimetry is reviewed. Topics covered include dosimetry needs and alternatives, current dosimetry approaches, personnel monitoring devices, calibration strategies, and future developments. (ACR)

  5. Ion storage dosimetry

    NASA Astrophysics Data System (ADS)

    Mathur, V. K.

    2001-09-01

    The availability of a reliable, accurate and cost-effective real-time personnel dosimetry system is fascinating to radiation workers. Electronic dosimeters are contemplated to meet this demand of active dosimetry. The development of direct ion storage (DIS) dosimeters, a member of the electronic dosimeter family, for personnel dosimetry is also an attempt in this direction. DIS dosimeter is a hybrid of the well-established technology of ion chambers and the latest advances in data storage using metal oxide semiconductor field effect transistor (MOSFET) analog memory device. This dosimeter is capable of monitoring legal occupational radiation doses of gamma, X-rays, beta and neutron radiation. Similar to an ion chamber, the performance of the dosimeter for a particular application can be optimized through the selection of appropriate wall materials. The use of the floating gate of a MOSFET as one of the electrodes of the ion chamber allows the miniaturization of the device to the size of a dosimetry badge and avoids the use of power supplies during dose accumulation. The concept of the device, underlying physics and the design of the DIS dosimeter are discussed. The results of preliminary testing of the device are also provided.

  6. Radiation dosimetry.

    PubMed Central

    Cameron, J

    1991-01-01

    This article summarizes the basic facts about the measurement of ionizing radiation, usually referred to as radiation dosimetry. The article defines the common radiation quantities and units; gives typical levels of natural radiation and medical exposures; and describes the most important biological effects of radiation and the methods used to measure radiation. Finally, a proposal is made for a new radiation risk unit to make radiation risks more understandable to nonspecialists. PMID:2040250

  7. SU-D-BRF-07: Ultrasound and Fluoroscopy Based Intraoperative Image-Guidance System for Dynamic Dosimetry in Prostate Brachytherapy

    SciTech Connect

    Kuo, N; Le, Y; Deguet, A; Prince, J; Song, D; Lee, J; Dehghan, E; Burdette, E; Fichtinger, G

    2014-06-01

    Purpose: Prostate brachytherapy is a common treatment method for low-risk prostate cancer patients. Intraoperative treatment planning is known to improve the treatment procedure and the outcome. The current limitation of intraoperative treatment planning is the inability to localize the seeds in relation to the prostate. We developed an image-guidance system to fulfill this need to achieve intraoperative dynamic dosimetry in prostate brachytherapy. Methods: Our system is based on standard imaging equipments available in the operating room, including the transrectal ultrasound (TRUS) and the mobile C-arm. A simple fiducial is added to compute the C-arm pose. Three fluoroscopic images and an ultrasound volume of the seeds and the prostate are acquired and processed by four image processing algorithms: seed segmentation, fiducial detection with pose estimation, seed reconstruction, and seeds-to-TRUS registration. The updated seed positions allow the physician to assess the quality of implantation and dynamically adjust the treatment plan during the course of surgery to achieve improved exit dosimetry. Results: The system was tested on 10 phantoms and 37 patients. Seed segmentation resulted in a 1% false negative and 2% false positive rates. Fiducial detection with pose estimation resulted in a detection rate of 98%. Seed reconstruction had a mean reconstruction error of 0.4 mm. Seeds-to-TRUS registration had a mean registration error of 1.3 mm. The total processing time from image acquisition to registration was approximately 1 minute. Conclusion: We present an image-guidance system for intraoperative dynamic dosimetry in prostate brachytherapy. Using standard imaging equipments and a simple fiducial, our system can be easily adopted in any clinics. Robust image processing algorithms enable accurate and fast computation of the delivered dose. Especially, the system enables detection of possible hot/cold spots during the surgery, allowing the physician to address these

  8. Surviving Hiroshima and Nagasaki--experiences and psychosocial meanings.

    PubMed

    Sawada, Aiko; Chaitin, Julia; Bar-On, Dan

    2004-01-01

    In spite of the fact that the A-bombings of Hiroshima and Nagasaki occurred nearly 60 years ago, there has been very little psychosocial research on the long-term effects of these unprecedented nuclear attacks on its victims. In this qualitative study, we use psychosocial literature from the Holocaust in order to help understand the effects of this man-made tragedy. We analyzed semi-structured interviews taken with 8 survivors of the bombs--5 from Nagasaki and 3 from Hiroshima. Our research questions were: When the survivors talk about their experiences, what do they focus on and with what are they preoccupied? What can we learn about the long-term effects of the experiences from both psychological and physical aspects? And, where does the A-bomb experience "fit" into the survivors' lives? Our analyses showed that there were 9 main themes that emerged from the interviews that could be grouped into two main categories--themes connected to the experience itself and themes connected to life afterward. We discuss the implications of these themes on the personal, social, and cultural levels and offer suggestions concerning ideas for dealing with the trauma. PMID:15139585

  9. Cancer risks and neutron RBE's from Hiroshima and Nagasaki

    SciTech Connect

    Dobson, R.L.; Straume, T.

    1982-03-25

    The new radiation dose estimates for Hiroshima and Nagasaki are radiobiologically examined for compatability with other human and experimental data. The new doses show certain improvements over the original T65 doses. However, they suggest for chronic granulocytic leukemia, total malignancies, and chromosome aberrations, at neutron doses of 1 rad, RBEs in excess of 100, higher than expected from other findings. This and other indications suggest that either there are unrecognized systematic problems with the various radiobiological data, or the new doses are deficient in neutrons for Hiroshima, by a factor of about five. If in fact there were actually some 5-fold more dose from neutrons at Hiroshima than estimated by the new calculations, the RBEs would agree well with laboratory results, and other inconsistencies would largely disappear. Cancer risks are estimated for neutrons from the new doses and are compared with those estimated from radiobiologically reconciled doses (the new doses adjusted by adding approximately 5-fold more neutrons). The latter appear more reasonable. For low-LET radiation, cancer risk estimates are changed very little by the new dose estimates for Nagasaki.

  10. Cancer risks and neutron RBE's from Hiroshima and Nagasaki

    SciTech Connect

    Dobson, R.L.; Straume, T.

    1982-04-30

    The new radiation dose estimates for Hiroshima and Nagasaki are here combined with epidemiologic data from the A-bomb survivors and examined radiobiologically for compatability with other human and experimental data. The new doses show certain improvements over the original T65 doses. However, they suggest for chronic granulocytic leukemia, total malignancies, and chromosome aberrations, at neutron doses of 1 rad, RBEs in excess of 100, higher than expected from other findings. This and other indications suggest that either there are unrecognized systematic problems with the various radiobiological data, or the new doses are deficient in neutrons for Hiroshima, by a factor of about five. If in fact there were actually some 5-fold more dose from neutrons at Hiroshima than estimated by the new calculations, the RBEs would agree well with laboratory results, and other inconsistencies would largely disappear. Cancer risks are estimated for neutrons from the new doses and are compared with those estimated from radiobiologically reconciled doses (the new doses adjusted by adding approximately 5-fold more neutrons). The latter estimates appear more reasonable. For low-LET radiation, cancer risk estimates are altered very little by the new dose estimates for Nagasaki.

  11. Polymer gel dosimetry for neutron beam in the Neutron Exposure Accelerator System for Biological Effect Experiments (NASBEE)

    NASA Astrophysics Data System (ADS)

    Kawamura, H.; Sato, H.; Hamano, T.; Suda, M.; Yoshii, H.

    2015-01-01

    This study aimed to investigate whether gel dosimetry could be used to measure neutron beams. We irradiated a BANG3-type polymer gel dosimeter using neutron beams in the Neutron exposure Accelerator System for Biological Effect Experiments (NASBEE) at the National Institute of Radiological Sciences (NIRS) in Japan. First, the polymer gels were irradiated from 0 to 7.0 Gy to investigate the dose-R2 responses. Irradiated gels were evaluated using 1.5-T magnetic resonance R2 images. Second, the polymer gels were irradiated to 1.0, 3.0, and 5.0 Gy to acquire a depth-R2 response curve. The dose-R2 response curve was linear up to approximately 7 Gy, with a slope of 1.25 Gy-1·s-1. Additionally, compared with the photon- irradiated gels, the neutron-irradiated gels had lower R2 values. The acquired depth-R2 curves of the central axis from the 3.0- and 5.0-Gy neutron dose-irradiated gels exhibited an initial build-up. Although, a detailed investigation is needed, polymer gel dosimetry is effective for measuring the dose-related R2 linearity and depth-R2 relationships of neutron beams.

  12. Breast dosimetry in transverse and longitudinal field MRI-Linac radiotherapy systems

    SciTech Connect

    Mahdavi, S. R.; Esmaeeli, A. D.; Pouladian, M.; Sardari, D.; Bagheri, S.; Monfared, A. S.

    2015-02-15

    Purpose: In the framework of developing the integration of a MRI-Linac system, configurations of MRI-Linac units were simulated in order to improve the dose distribution in tangential breast radiotherapy using transverse and longitudinal magnetic field geometries of Lorentz force for both medial and lateral tangential fields. Methods: In this work, the GEANT4 Monte Carlo (MC) code was utilized to compare dose distributions in breast radiotherapy for Linac-MR systems in the transverse and longitudinal geometries within humanoid phantoms across a range of magnetic field strengths of 0.5 and 1.5 T. The dose increment due to scattering from the coils was investigated for both geometries as well. Computed tomography images of two patients were used for MC simulations. One patient had intact breast while the other was mastectomized. In the simulations, planning and methods of chest wall irradiation were similar to the actual clinical planning. Results: In a longitudinal geometry, the magnetic field is shown to restrict the lateral spread of secondary electrons to the lung, heart, and contralateral organs, which reduced the mean dose of the ipsilateral lung and heart by means of 17.2% and 6% at 1.5 T, respectively. The transverse configuration exhibits a significant increase in tissue interface effects, which increased dose buildup in the entrance regions of the lateral and medial tangent beams to the planning target volume (PTV) and improved dose homogeneity within the PTV. The improved relative average homogeneity index for two patients to the PTV at magnetic field strength of 1.5 T with respect to no magnetic field case evaluated was 11.79% and 34.45% in the LRBP and TRBP geometries, respectively. In both geometries, the simulations show significant mean dose reductions in the contralateral breast and chest wall skin, respectively, by a mean of 16.6% and 24.9% at 0.5 T and 17.2% and 28.1% at 1.5 T in the transverse geometry, and 10.56% and 14.6% at 0.5 T and 11.3% and

  13. The ENEA criticality accident dosimetry system: a contribution to the 2002 international intercomparison at the SILENE reactor.

    PubMed

    Gualdrini, G; Bedogni, R; Fantuzzi, E; Mariotti, F

    2004-01-01

    The present paper summarises the activity carried out at the ENEA Radiation Protection Institute for updating the methodologies employed for the evaluation of the neutron and photon dose to the exposed workers in case of a criticality accident, in the framework of the 'International Intercomparison of Criticality Accident Dosimetry Systems' (Silène reactor, IRSN-CEA-Valduc June 2002). The evaluation of the neutron spectra and the neutron dosimetric quantities relies on activation detectors and on unfolding algorithms. Thermoluminescent detectors are employed for the gamma dose measurement. The work is aimed at accurately characterising the measurement system and, at the same time, testing the algorithms. Useful spectral information were included, based on Monte Carlo simulations, to take into account the potential accident scenarios of practical interest. All along this exercise intercomparison a particular attention was devoted to the 'traceability' of all the experimental and computational parameters and therefore, aimed at an easy treatment by the user. PMID:15353692

  14. Evaluation of a lithium formate EPR dosimetry system for dose measurements around {sup 192}Ir brachytherapy sources

    SciTech Connect

    Antonovic, Laura; Gustafsson, Haakan; Alm Carlsson, Gudrun; Carlsson Tedgren, Aasa

    2009-06-15

    A dosimetry system using lithium formate monohydrate (HCO{sub 2}Li{center_dot}H{sub 2}O) as detector material and electron paramagnetic resonance (EPR) spectroscopy for readout has been used to measure absorbed dose distributions around clinical {sup 192}Ir sources. Cylindrical tablets with diameter of 4.5 mm, height of 4.8 mm, and density of 1.26 g/cm{sup 3} were manufactured. Homogeneity test and calibration of the dosimeters were performed in a 6 MV photon beam. {sup 192}Ir irradiations were performed in a PMMA phantom using two different source models, the GammaMed Plus HDR and the microSelectron PDR-v1 model. Measured absorbed doses to water in the PMMA phantom were converted to the corresponding absorbed doses to water in water phantoms of dimensions used by the treatment planning systems (TPSs) using correction factors explicitly derived for this experiment. Experimentally determined absorbed doses agreed with the absorbed doses to water calculated by the TPS to within {+-}2.9%. Relative standard uncertainties in the experimentally determined absorbed doses were estimated to be within the range of 1.7%-1.3% depending on the radial distance from the source, the type of source (HDR or PDR), and the particular absorbed doses used. This work shows that a lithium formate dosimetry system is well suited for measurements of absorbed dose to water around clinical HDR and PDR {sup 192}Ir sources. Being less energy dependent than the commonly used thermoluminescent lithium fluoride (LiF) dosimeters, lithium formate monohydrate dosimeters are well suited to measure absorbed doses in situations where the energy dependence cannot easily be accounted for such as in multiple-source irradiations to verify treatment plans. Their wide dynamic range and linear dose response over the dose interval of 0.2-1000 Gy make them suitable for measurements on sources of the strengths used in clinical applications. The dosimeter size needs, however, to be reduced for application to

  15. Experimental verification of internal dosimetry calculations. Annual progress report

    SciTech Connect

    1980-05-01

    During the past year a dosimetry research program has been established in the School of Nuclear Engineering at the Georgia Institute of Technology. The major objective of this program has been to provide research results upon which a useful internal dosimetry system could be based. The important application of this dosimetry system will be the experimental verification of internal dosimetry calculations such as those published by the MIRD Committee.

  16. Nuclear past, nuclear present: Hiroshima, Nagasaki, and contemporary strategy

    SciTech Connect

    Clark, I.

    1985-01-01

    The controversial atomic bombings of Hiroshima and Nagasaki in 1945 represent the only occasions when atomic weapons have been employed in war, yet surprisingly little attention has been paid to the relationship between the bombings and the course of subsequent nuclear strategy. Dr. Clark contends that the August 1945 experience was crucially formative and gave rise to a set of influential assumptions about the moral acceptability of using nuclear weapons, the rationality of nuclear decision-making, and the controllability of nuclear operations. The author's detailed reconstruction of the events of 1945 sheds new light upon these assumptions and contributes to the present debate about nuclear strategy, tracing present nuclear strategy, tracing present nuclear concerns and problems back to some of the misleading conclusions drawn from the bombings.

  17. Hanford External Dosimetry Program

    SciTech Connect

    Fix, J.J.

    1990-10-01

    This document describes the Hanford External Dosimetry Program as it is administered by Pacific Northwest Laboratory (PNL) in support of the US Department of Energy (DOE) and its Hanford contractors. Program services include administrating the Hanford personnel dosimeter processing program and ensuring that the related dosimeter data accurately reflect occupational dose received by Hanford personnel or visitors. Specific chapters of this report deal with the following subjects: personnel dosimetry organizations at Hanford and the associated DOE and contractor exposure guidelines; types, characteristics, and procurement of personnel dosimeters used at Hanford; personnel dosimeter identification, acceptance testing, accountability, and exchange; dosimeter processing and data recording practices; standard sources, calibration factors, and calibration processes (including algorithms) used for calibrating Hanford personnel dosimeters; system operating parameters required for assurance of dosimeter processing quality control; special dose evaluation methods applied for individuals under abnormal circumstances (i.e., lost results, etc.); and methods for evaluating personnel doses from nuclear accidents. 1 ref., 14 figs., 5 tabs.

  18. Dosimetry for Radiopharmaceutical Therapy

    PubMed Central

    Sgouros, George; Hobbs, Robert F.

    2014-01-01

    Radiopharmaceutical therapy (RPT) involves the use of radionuclides that are either conjugated to tumor-targeting agents (eg, nanoscale constructs, antibodies, peptides, and small molecules) or concentrated in tissue through natural physiological mechanisms that occur predominantly in neoplastic or otherwise targeted cells (eg, Graves disease). The ability to collect pharmacokinetic data by imaging and use this to perform dosimetry calculations for treatment planning distinguishes RPT from other systemic treatment modalities. Treatment planning has not been widely adopted, in part, because early attempts to relate dosimetry to outcome were not successful. This was partially because a dosimetry methodology appropriate to risk evaluation rather than efficacy and toxicity was being applied to RPT. The weakest links in both diagnostic and therapeutic dosimetry are the accuracy of the input and the reliability of the radiobiological models used to convert dosimetric data to the relevant biologic end points. Dosimetry for RPT places a greater demand on both of these weak links. To date, most dosimetric studies have been retrospective, with a focus on tumor dose-response correlations rather than prospective treatment planning. In this regard, transarterial radioembolization also known as intra-arterial radiation therapy, which uses radiolabeled (90Y) microspheres of glass or resin to treat lesions in the liver holds much promise for more widespread dosimetric treatment planning. The recent interest in RPT with alpha-particle emitters has highlighted the need to adopt a dosimetry methodology that specifically accounts for the unique aspects of alpha particles. The short range of alpha-particle emitters means that in cases in which the distribution of activity is localized to specific functional components or cell types of an organ, the absorbed dose will be equally localized and dosimetric calculations on the scale of organs or even voxels (~5 mm) are no longer sufficient

  19. Neutron-induced 63Ni in copper samples from Hiroshima and Nagasaki: a comprehensive presentation of results obtained at the Munich Maier-Leibnitz Laboratory.

    PubMed

    Rühm, W; Carroll, K L; Egbert, S D; Faestermann, T; Knie, K; Korschinek, G; Martinelli, R E; Marchetti, A A; McAninch, J E; Rugel, G; Straume, T; Wallner, A; Wallner, C; Fujita, S; Hasai, H; Hoshi, M; Shizuma, K

    2007-11-01

    Those inhabitants of Hiroshima and Nagasaki who were affected by the A-bomb explosions, were exposed to a mixed neutron and gamma radiation field. Few years later about 120,000 survivors of both cities were selected, and since then radiation-induced late effects such as leukemia and solid tumors are being investigated in this cohort. When the present study was initiated, the fast neutron fluences that caused the neutron doses of these survivors had never been determined experimentally. In principle, this would have been possible if radioisotopes produced by fast neutrons from the A-bomb explosions had been detected in samples from Hiroshima and Nagasaki at distances where the inhabitants survived. However, no suitable radioisotope had so far been identified. As a contribution to a large international effort to re-evaluate the A-bomb dosimetry, the concentration of the radionuclide (63)Ni (half-life 100.1 years) has been measured in copper samples from Hiroshima and Nagasaki. These measurements were mainly performed at the Maier-Leibnitz-Laboratory in Munich, Germany, by means of accelerator mass spectrometry. Because the (63)Ni had been produced in these samples by fast A-bomb neutrons via the reaction (63)Cu(n,p)(63)Ni, these measurements allow direct experimental validation of calculated neutron doses to the members of the LSS cohort, for the first time. The results of these efforts have already been published in a compact form. A more detailed discussion of the methodical aspects of these measurements and their results are given in the present paper. Eight copper samples that had been significantly exposed to fast neutrons from the Hiroshima A-bomb explosion were investigated. In general, measured (63)Ni concentrations decreased in these samples with increasing distance to the hypocenter, from 4 x 10(6 ) (63)Ni nuclei per gram copper at 391 m, to about 1 x 10(5 ) (63)Ni nuclei per gram copper at about 1,400 m. Additional measurements performed on three large

  20. Personnel neutron dosimetry at Department of Energy facilities

    SciTech Connect

    Brackenbush, L.W.; Endres, G.W.R.; Selby, J.M.; Vallario, E.J.

    1980-08-01

    This study assesses the state of personnel neutron dosimetry at DOE facilities. A survey of the personnel dosimetry systems in use at major DOE facilities was conducted, a literature search was made to determine recent advances in neutron dosimetry, and several dosimetry experts were interviewed. It was concluded that personnel neutron dosimeters do not meet current needs and that serious problems exist now and will increase in the future if neutron quality factors are increased and/or dose limits are lowered.

  1. SU-E-T-407: Evaluation of Four Commercial Dosimetry Systems for Routine Patient-Specific Tomotherapy Delivery Quality Assurance

    SciTech Connect

    Xing, A; Arumugam, S; Deshpande, S; George, A; Holloway, L; Vial, P; Goozee, G

    2014-06-01

    Purpose: The purpose of this project was to evaluate the performance of four commercially available dosimetry systems for Tomotherapy delivery quality assurance (DQA). Methods: Eight clinical patient plans were chosen to represent a range of treatment sites and typical clinical plans. Four DQA plans for each patient plan were created using the TomoTherapy DQA Station (Hi-Art version 4.2.1) on CT images of the ScandiDose Delta4, IBA MatriXX Evolution, PTW Octavius 4D and Sun Nuclear ArcCHECK phantoms. Each detector was calibrated following the manufacture-provided procedure. No angular response correction was applied. All DQA plans for each detector were delivered on the Tomotherapy Hi-Art unit in a single measurement session but on different days. The measured results were loaded into the vendor supplied software for each QA system for comparison with the TPS-calculated dose. The Gamma index was calculated using 3%/3mm, 2%/2mm with 10% dose threshold of maximum TPS calculated dose. Results: Four detector systems showed comparable gamma pass rates for 3%/3m, which is recommended by AAPM TG119 and commonly used within the radiotherapy community. The averaged pass rates ± standard deviation for all DQA plans were (98.35±1.97)% for ArcCHECK, (99.9%±0.87)% for Matrix, (98.5%±5.09)% for Octavius 4D, (98.7%±1.27)% for Delata4. The rank of the gamma pass rate for individual plans was consistent between detectors. Using 2%/2mm Gamma criteria for analysis, the Gamma pass rate decreased on average by 9%, 8%, 6.6% and 5% respectively. Profile and Gamma failure map analysis using the software tools from each dosimetry system indicated that decreased passing rate is mainly due to the threading effect of Tomo plan. Conclusion: Despite the variation in detector type and resolution, phantom geometry and software implementation, the four systems demonstrated similar dosimetric performance, with the rank of the gamma pass rate consistent for the plans considered.

  2. CUSTOMISATION OF A MONTE CARLO DOSIMETRY TOOL FOR DENTAL CONE-BEAM CT SYSTEMS.

    PubMed

    Stratis, A; Zhang, G; Lopez-Rendon, X; Jacobs, R; Bogaerts, R; Bosmans, H

    2016-06-01

    A versatile EGSnrc Monte Carlo (MC) framework, initially designed to explicitly simulate X-ray tubes and record the output data into phase space data files, was modified towards dental cone-beam computed tomography (CBCT) dosimetric applications by introducing equivalent sources. Half value layer (HVL) measurements were conducted to specify protocol-specific energy spectra. Air kerma measurements were carried out with an ionisation chamber positioned against the X-ray tube to obtain the total filtration attenuation characteristics. The framework is applicable to bowtie and non-bowtie inherent filtrations, and it accounts for the anode heel effect and the total filtration of the tube housing. The code was adjusted to the Promax 3D Max (Planmeca, Helsinki, Finland) dental CBCT scanner. For each clinical protocol, calibration factors were produced to allow absolute MC dose calculations. The framework was validated by comparing MC calculated doses and measured doses in a cylindrical water phantom. Validation results demonstrate the reliability of the framework for dental CBCT dosimetry purposes. PMID:26922781

  3. Monte Carlo simulation of a prototypical patient dosimetry system for fluoroscopic procedures

    NASA Astrophysics Data System (ADS)

    Goertz, Lukas; Tsiamas, Panagiotis; Karellas, Andrew; Sajo, Erno; Zygmanski, Piotr

    2015-08-01

    The purpose of this study is to investigate feasibility of a novel real-time dosimetry method for fluoroscopically guided interventions utilizing thin-film detector arrays in several potential locations with respect to the patient and x-ray equipment. We employed Monte Carlo (MC) simulation to establish the fluoroscopic beam model to determine dosimetric quantities directly from measured doses in thin-film detector arrays at three positions: A—attached to the x-ray source, B—on the couch under the patient and C—attached to the fluoroscopic imager. Next, we developed a calibration method to determine skin dose at the entry of the beam ({{D}\\text{entr}} ) as well as the dose distribution along each ray of the beam in a water-equivalent patient model. We utilized the concept of water-equivalent thickness to determine the dose inside the patient based on doses measured outside of the patient by the thin-film detector array layers: (a) A, (b) B, or (c) B and C. In the process of calibration we determined a correction factor that characterizes the material-specific response of the detector, backscatter factor and attenuation factor for slab water phantoms of various thicknesses. Application of this method to an anthropomorphic phantom showed accuracy of about 1% for {{D}\\text{entr}} and up to about 10% for integral dose along the beam path when compared to a direct simulation of dose by MC.

  4. Progress In The Development Of A Tomographic SPECT System For Online Dosimetry In BNCT

    NASA Astrophysics Data System (ADS)

    Minsky, D. M.; Valda, A.; Kreiner, A. J.; Burlon, A. A.; Green, S.; Wojnecki, C.; Ghani, Z.

    2010-08-01

    In boron neutron capture therapy (BNCT) the delivered dose to the patient depends both on the neutron beam characteristics and on the 10B body distribution which, in turn, is governed by the tumor specificity of the 10B drug-carrier. BNCT dosimetry is a complex matter due to the several interactions that neutrons can undergo with the different nuclei present in tissue. However the boron capture reaction 10B(n,α)7Li accounts for about 80 % of the total dose in a tumor with 40 ppm in 10B concentration. Present dosimetric methods are indirect, based on drug biodistribution statistical data and subjected to inter and intra-patient variability. In order to overcome the consequences of the concomitant high dosimetric uncertainties, we propose a SPECT (Single Photon Emission Tomography) approach based on the detection of the prompt gamma-ray (478 keV) emitted in 94 % of the cases from 7Li. For this purpose we designed, built and tested a prototype based on LaBr3(Ce) scintillators. Measurements on a head and tumor phantom were performed in the accelerator-based BNCT facility of the University of Birmingham (UK). They result in the first tomographic image of the 10B capture distribution obtained in a BNCT facility.

  5. Monte Carlo simulation of a prototypical patient dosimetry system for fluoroscopic procedures.

    PubMed

    Goertz, Lukas; Tsiamas, Panagiotis; Karellas, Andrew; Sajo, Erno; Zygmanski, Piotr

    2015-08-01

    The purpose of this study is to investigate feasibility of a novel real-time dosimetry method for fluoroscopically guided interventions utilizing thin-film detector arrays in several potential locations with respect to the patient and x-ray equipment. We employed Monte Carlo (MC) simulation to establish the fluoroscopic beam model to determine dosimetric quantities directly from measured doses in thin-film detector arrays at three positions: A-attached to the x-ray source, B-on the couch under the patient and C-attached to the fluoroscopic imager. Next, we developed a calibration method to determine skin dose at the entry of the beam ([Formula: see text]) as well as the dose distribution along each ray of the beam in a water-equivalent patient model. We utilized the concept of water-equivalent thickness to determine the dose inside the patient based on doses measured outside of the patient by the thin-film detector array layers: (a) A, (b) B, or (c) B and C. In the process of calibration we determined a correction factor that characterizes the material-specific response of the detector, backscatter factor and attenuation factor for slab water phantoms of various thicknesses. Application of this method to an anthropomorphic phantom showed accuracy of about 1% for [Formula: see text] and up to about 10% for integral dose along the beam path when compared to a direct simulation of dose by MC. PMID:26184743

  6. Progress In The Development Of A Tomographic SPECT System For Online Dosimetry In BNCT

    SciTech Connect

    Minsky, D. M.; Kreiner, A. J.; Valda, A.; Burlon, A. A.; Green, S.; Wojnecki, C.; Ghani, Z.

    2010-08-04

    In boron neutron capture therapy (BNCT) the delivered dose to the patient depends both on the neutron beam characteristics and on the {sup 10}B body distribution which, in turn, is governed by the tumor specificity of the {sup 10}B drug-carrier. BNCT dosimetry is a complex matter due to the several interactions that neutrons can undergo with the different nuclei present in tissue. However the boron capture reaction {sup 10}B(n,{alpha}){sup 7}Li accounts for about 80 % of the total dose in a tumor with 40 ppm in {sup 10}B concentration. Present dosimetric methods are indirect, based on drug biodistribution statistical data and subjected to inter and intra-patient variability. In order to overcome the consequences of the concomitant high dosimetric uncertainties, we propose a SPECT (Single Photon Emission Tomography) approach based on the detection of the prompt gamma-ray (478 keV) emitted in 94 % of the cases from {sup 7}Li. For this purpose we designed, built and tested a prototype based on LaBr{sub 3}(Ce) scintillators. Measurements on a head and tumor phantom were performed in the accelerator-based BNCT facility of the University of Birmingham (UK). They result in the first tomographic image of the 10B capture distribution obtained in a BNCT facility.

  7. Reassessment of the cancer mortality risk among Hiroshima atomic-bomb survivors using a new dosimetry system, ABS2000D, compared with ABS93D.

    PubMed

    Katayama, Hiroaki; Matsuura, Masaaki; Endo, Satoru; Hoshi, Masaharu; Ohtaki, Megu; Hayakawa, Norihiko

    2002-03-01

    The aim of the present study was to examine the excess relative risk for leukemia mortality and all cancers, except leukemia, among Hiroshima atomic-bomb survivors by applying ABS93D and ABS2000D. Particular attention was given to any difference in the neutron-dose estimates between the two dosimetry systems. The study subjects were 51,532 atomic-bomb survivors registered in a database of the Research Institute for Radiation Biology and Medicine of Hiroshima University (RIRBM). The results obtained by both dosimetry systems are similar: the excess relative risk per Sv for leukemia mortality and all cancers except leukemia is significantly higher compared to the control group. In addition, the difference in the excess relative risks between the two systems is not significant. Therefore, it is indicated that a modification of the neutron-dose estimates would not markedly change the conclusions about the cancer mortality risk. PMID:12056330

  8. TVA's dosimetry technician training program

    SciTech Connect

    Hudson, C.G.; Faust, V.L.; Cornelius, T.W.; Regan, J.M.; Farrell, W.E. )

    1984-04-01

    In 1984, the Tennessee Valley Authority decentralized its personnel TLD program and established TLD processing facilities at each of its nuclear plant sites. This article describes the training program that was developed to aid in staffing dosimetry technician positions at each of the plants. The scope of the dosimetry technician's duties include TLD processing, operation of a computerized records system, whole-body counting system operation, and respirator mask fit-testing. The training program includes thirteen weeks of classroom and laboratory training plus a 15-month apprenticeship at a nuclear plant. Retraining and requalification are performed on an annual basis.

  9. Dosimetry in radiotherapy using a-Si EPIDs: Systems, methods, and applications focusing on 3D patient dose estimation

    NASA Astrophysics Data System (ADS)

    McCurdy, B. M. C.

    2013-06-01

    An overview is provided of the use of amorphous silicon electronic portal imaging devices (EPIDs) for dosimetric purposes in radiation therapy, focusing on 3D patient dose estimation. EPIDs were originally developed to provide on-treatment radiological imaging to assist with patient setup, but there has also been a natural interest in using them as dosimeters since they use the megavoltage therapy beam to form images. The current generation of clinically available EPID technology, amorphous-silicon (a-Si) flat panel imagers, possess many characteristics that make them much better suited to dosimetric applications than earlier EPID technologies. Features such as linearity with dose/dose rate, high spatial resolution, realtime capability, minimal optical glare, and digital operation combine with the convenience of a compact, retractable detector system directly mounted on the linear accelerator to provide a system that is well-suited to dosimetric applications. This review will discuss clinically available a-Si EPID systems, highlighting dosimetric characteristics and remaining limitations. Methods for using EPIDs in dosimetry applications will be discussed. Dosimetric applications using a-Si EPIDs to estimate three-dimensional dose in the patient during treatment will be overviewed. Clinics throughout the world are implementing increasingly complex treatments such as dynamic intensity modulated radiation therapy and volumetric modulated arc therapy, as well as specialized treatment techniques using large doses per fraction and short treatment courses (ie. hypofractionation and stereotactic radiosurgery). These factors drive the continued strong interest in using EPIDs as dosimeters for patient treatment verification.

  10. Personnel neutron dosimetry

    SciTech Connect

    Hankins, D.

    1982-04-01

    This edited transcript of a presentation on personnel neutron discusses the accuracy of present dosimetry practices, requirements, calibration, dosemeter types, quality factors, operational problems, and dosimetry for a criticality accident. 32 figs. (ACR)

  11. Nuclear accident dosimetry intercomparison studies.

    PubMed

    Sims, C S

    1989-09-01

    Twenty-two nuclear accident dosimetry intercomparison studies utilizing the fast-pulse Health Physics Research Reactor at the Oak Ridge National Laboratory have been conducted since 1965. These studies have provided a total of 62 different organizations a forum for discussion of criticality accident dosimetry, an opportunity to test their neutron and gamma-ray dosimetry systems under a variety of simulated criticality accident conditions, and the experience of comparing results with reference dose values as well as with the measured results obtained by others making measurements under identical conditions. Sixty-nine nuclear accidents (27 with unmoderated neutron energy spectra and 42 with eight different shielded spectra) have been simulated in the studies. Neutron doses were in the 0.2-8.5 Gy range and gamma doses in the 0.1-2.0 Gy range. A total of 2,289 dose measurements (1,311 neutron, 978 gamma) were made during the intercomparisons. The primary methods of neutron dosimetry were activation foils, thermoluminescent dosimeters, and blood sodium activation. The main methods of gamma dose measurement were thermoluminescent dosimeters, radiophotoluminescent glass, and film. About 68% of the neutron measurements met the accuracy guidelines (+/- 25%) and about 52% of the gamma measurements met the accuracy criterion (+/- 20%) for accident dosimetry. PMID:2777549

  12. Radiation exposure inside reinforced concrete buildings at Nagasaki

    SciTech Connect

    Rhoades, W.A.; Childs, R.L.; Ingersoll, D.T.

    1989-05-01

    The biological effects on the residents of Hiroshima and Nagasaki due to initial-irradiation exposure during the nuclear attacks of World War II was recognized immediately as an important source of information. After the war, an extensive effort gathered data concerning the locations of individuals at the time of the attack and their subsequent medical histories. The data from personnel located in reinforced concrete buildings are particularly significant, since large groups of occupants received radiation injury without complications due to blast and thermal effects. In order to correlate the radiation dose with physiological effects, the dose to each individual must be calculated. Enough information about the construction of the buildings was available after the war to allow a radiation transport model to be constructed, but the accurate calculation of penetration into such large, thick-walled three dimensional structures was beyond the scope of computing technology until recently. Now, the availability of Cray vector computers and the development of a specially-constructed discrete ordinates transport code, TORT, have combined to allow the successful completion of such a study. This document describes the radiation transport calculations and tabulates the resulting doses by source component and individual case location. An extensive uncertainty analysis is also included. These data are to be used in another study as input to a formal statistical analysis, resulting in a new value for the LD50 dose, i.e., the dose at which the mortality risk is 50%. 55 refs., 67 figs., 70 tabs.

  13. Learning disabilities in individuals exposed prenatally to ionizing radiation: The Hiroshima and Nagasaki experiences

    NASA Astrophysics Data System (ADS)

    Schull, William J.; Otake, Masanori

    The brain, undoubtedly the most complex organ in the mammalian body, is the culmination of a long and interrelated sequence of molecular, cellular and tissue events. Brain function hinges on the orderly progression of these, each of which must occur correctly, temporally and spatially. Impingement on any one will give rise to a less developed system of cellular connections, and hence impaired function. Moreover, the neurons of the central nervous system are not self-renewing and thus neuronal loss cannot be repaired through repopulation. Reanalysis of the data on the prenatally exposed survivors of the atomic bombing of Hiroshima and Nagasaki suggests that severe mental retardation occurs primarily, if not exclusively in the period from the 8th through the 15th week following fertilization. Within this window of vulnerability, the increase in mental retardation appears linear with dose and without theshold. More subtle functional effects also occur as reflected in diminished performance on intelligence tests and in school. These findings and their implications for space travel and regulatory agencies charged with the specification of acceptable risks should not require further elaboration in this article given the focus of the radiobiological presentations at this meeting.

  14. Learning disabilities in individuals exposed prenatally to ionizing radiation: the Hiroshima and Nagasaki experiences.

    PubMed

    Schull, W J; Otake, M

    1986-01-01

    The brain, undoubtedly the most complex organ in the mammalian body, is the culmination of a long and interrelated sequence of molecular, cellular and tissue events. Brain function hinges on the orderly progression of these, each of which must occur correctly, temporally and spatially. Impingement on any one will give rise to a less developed system of cellular connections, and hence impaired function. Moreover, the neurons of the central nervous system are not self-renewing and thus neuronal loss cannot be repaired through repopulation. Reanalysis of the data on the prenatally exposed survivors of the atomic bombing of Hiroshima and Nagasaki suggests that severe mental retardation occurs primarily, if not exclusively in the period from the 8th through the 15th week following fertilization. Within this window of vulnerability, the increase in mental retardation appears linear with dose and without threshold. More subtle functional effects also occur as reflected in diminished performance on intelligence tests and in school. These findings and their implications for space travel and regulatory agencies charged with the specification of acceptable risks should not require further elaboration in this article given the focus of the radiobiological presentations at this meeting. PMID:11537225

  15. Commissioning and Implementation of an EPID Based IMRT QA System "Dosimetry Check" for 3D Absolute Dose Measurements and Quantitative Comparisons to MapCheck

    NASA Astrophysics Data System (ADS)

    Patel, Jalpa A.

    The software package "Dosimetry Check" by MathResolutions, LLC, provides an absolute 3D volumetric dose measurement for IMRT QA using the existing Electronic Portal Imaging Device (EPID) mounted on most linear accelerators. This package provides a feedback loop using the patient's treatment planning CT data as the phantom for dose reconstruction. The aim of this work is to study the difference between point, planar and volumetric doses with MapCheck and Dosimetry Check via the use of the EPID and the diode array respectively. Evaluating tools such as point doses at isocenter, 1-D profiles, gamma volume histograms, and dose volume histograms are used for IMRT dose comparison in three types of cases: head and neck, prostate, and lung. Dosimetry Check can be a valuable tool for IMRT QA as it uses patient specific attenuation corrections and the superiority of the EPID as compared to the MapCheck diode array. This helps reduce the uncertainty in dose for less variability in delivery and a more realistic measured vs computed dose verification system as compared to MapCheck.

  16. Liquid radiochromic dosimetry

    NASA Astrophysics Data System (ADS)

    Rativanich, N.; Radak, B. B.; Miller, A.; Uribe, R. M.; McLaughlin, W. L.

    By strategic combination of weak acid, mild oxidizing agent, and polar organic solvents containing millimolar concentrations of leucocyanides of certain triphenylmethane dyes, fairly broad ranges of absorbed doses of ionizing radiation can be determined. The yield of dye ions as determined by spectrophotometry can be made essentially constant with dose (i.e. linear response) from 0.01 to 30 kGy and it does not vary with dose rate upto 10 11 Gy·s -1. The radiation-induced color is stable and offers fast-retrieval dosimetry if N-vinyl-2-pyrrolidone is used as solvent. Other possible polar solvents are 2-propanol, 2-methoxy ethanol, N, N-dimethyl formamide, dimethyl sulfoxide, and triethyl phosphate. Dimethyl sulfoxide is found to give the widest and most linear response. Suitable dye precursors are leucocyanides of pararosaniline, new fuchsin, hexa (hydroxyethyl) pararosaniline, crystal violet, malachite green, setoglaucine, ethyl violet, helvetia green, basic violet-14, and formyl violet. Low concentrations of carboxylic acids contribute stability to the system. Typical mild oxidizing agents are nitrobenzene, and atmospheric oxygen, or oxygen released radiolytically from the solvents. The dosimetry systems do not require high-purity of ingredients or ultracleanliness of containers, although, for reproducibility of dye yields (G-values), thoroughly purified and uniform dye derivates are recommended.

  17. Quality audit of megavoltage radiotherapy units: intercomparison of dose at a reference point using a mailed TL-dosimetry system.

    PubMed

    Davis, B; Faessler, P

    1993-07-01

    A dosimetry intercomparison based on mailed TL-dosimeters and the well proven IAEA/EORTC phantom is described. Its aim is to identify discrepancies in dosimetry larger than +/- 3%. Dosimeters were mailed to all radiotherapy centres in Switzerland for irradiation with 2 Gy at a reference point in a water container, using photons and electrons. Thirty-six beams were monitored. The results show an agreement of within 2% for the majority of the beams monitored. Two electron beams were at 6% of the reference value. PMID:8234874

  18. SU-E-T-435: Development and Commissioning of a Complete System for In-Vivo Dosimetry and Range Verification in Proton Therapy

    SciTech Connect

    Samuel, D; Testa, M; Park, Y; Schneider, R; Moteabbed, M; Janssens, G; Prieels, D; Orban de Xivry, J; Lu, H; Bentefour, E

    2014-06-01

    Purpose: In-vivo dose and beam range verification in proton therapy could play significant roles in proton treatment validation and improvements. Invivo beam range verification, in particular, could enable new treatment techniques one of which, for example, could be the use of anterior fields for prostate treatment instead of opposed lateral fields as in current practice. We have developed and commissioned an integrated system with hardware, software and workflow protocols, to provide a complete solution, simultaneously for both in-vivo dosimetry and range verification for proton therapy. Methods: The system uses a matrix of diodes, up to 12 in total, but separable into three groups for flexibility in application. A special amplifier was developed to capture extremely small signals from very low proton beam current. The software was developed within iMagX, a general platform for image processing in radiation therapy applications. The range determination exploits the inherent relationship between the internal range modulation clock of the proton therapy system and the radiological depth at the point of measurement. The commissioning of the system, for in-vivo dosimetry and for range verification was separately conducted using anthropomorphic phantom. EBT films and TLDs were used for dose comparisons and range scan of the beam distal fall-off was used as ground truth for range verification. Results: For in-vivo dose measurement, the results were in agreement with TLD and EBT films and were within 3% from treatment planning calculations. For range verification, a precision of 0.5mm is achieved in homogeneous phantoms, and a precision of 2mm for anthropomorphic pelvic phantom, except at points with significant range mixing. Conclusion: We completed the commissioning of our system for in-vivo dosimetry and range verification in proton therapy. The results suggest that the system is ready for clinical trials on patient.

  19. Analysis of direct clinical consequences of MLC positional errors in volumetric-modulated arc therapy using 3D dosimetry system.

    PubMed

    Nithiyanantham, Karthikeyan; Mani, Ganesh K; Subramani, Vikraman; Mueller, Lutz; Palaniappan, Karrthick K; Kataria, Tejinder

    2015-01-01

    In advanced, intensity-modulated external radiotherapy facility, the multileaf collimator has a decisive role in the beam modulation by creating multiple segments or dynamically varying field shapes to deliver a uniform dose distribution to the target with maximum sparing of normal tissues. The position of each MLC leaf has become more critical for intensity-modulated delivery (step-and-shoot IMRT, dynamic IMRT, and VMAT) compared to 3D CRT, where it defines only field boundaries. We analyzed the impact of the MLC positional errors on the dose distribution for volumetric-modulated arc therapy, using a 3D dosimetry system. A total of 15 VMAT cases, five each for brain, head and neck, and prostate cases, were retrospectively selected for the study. All the plans were generated in Monaco 3.0.0v TPS (Elekta Corporation, Atlanta, GA) and delivered using Elekta Synergy linear accelerator. Systematic errors of +1, +0.5, +0.3, 0, -1, -0.5, -0.3 mm were introduced in the MLC bank of the linear accelerator and the impact on the dose distribution of VMAT delivery was measured using the COMPASS 3D dosim-etry system. All the plans were created using single modulated arcs and the dose calculation was performed using a Monte Carlo algorithm in a grid size of 3 mm. The clinical endpoints D95%, D50%, D2%, and Dmax,D20%, D50% were taken for the evaluation of the target and critical organs doses, respectively. A significant dosimetric effect was found for many cases even with 0.5 mm of MLC positional errors. The average change of dose D 95% to PTV for ± 1 mm, ± 0.5 mm, and ±0.3mm was 5.15%, 2.58%, and 0.96% for brain cases; 7.19%, 3.67%, and 1.56% for head and neck cases; and 8.39%, 4.5%, and 1.86% for prostate cases, respectively. The average deviation of dose Dmax was 5.4%, 2.8%, and 0.83% for brainstem in brain cases; 8.2%, 4.4%, and 1.9% for spinal cord in H&N; and 10.8%, 6.2%, and 2.1% for rectum in prostate cases, respectively. The average changes in dose followed a linear

  20. Measurement of stray radiation within a scanning proton therapy facility: EURADOS WG9 intercomparison exercise of active dosimetry systems

    SciTech Connect

    Farah, J. Trompier, F.; Mares, V.; Schinner, K.; Wielunski, M.; Romero-Expósito, M.; Domingo, C.; Trinkl, S.; Dufek, V.; Klodowska, M.; Liszka, M.; Stolarczyk, L.; Olko, P.; Kubancak, J.; and others

    2015-05-15

    Purpose: To characterize stray radiation around the target volume in scanning proton therapy and study the performance of active neutron monitors. Methods: Working Group 9 of the European Radiation Dosimetry Group (EURADOS WG9—Radiation protection in medicine) carried out a large measurement campaign at the Trento Centro di Protonterapia (Trento, Italy) in order to determine the neutron spectra near the patient using two extended-range Bonner sphere spectrometry (BSS) systems. In addition, the work focused on acknowledging the performance of different commercial active dosimetry systems when measuring neutron ambient dose equivalents, H{sup ∗}(10), at several positions inside (8 positions) and outside (3 positions) the treatment room. Detectors included three TEPCs—tissue equivalent proportional counters (Hawk type from Far West Technology, Inc.) and six rem-counters (WENDI-II, LB 6411, RadEye™ NL, a regular and an extended-range NM2B). Meanwhile, the photon component of stray radiation was deduced from the low-lineal energy transfer part of TEPC spectra or measured using a Thermo Scientific™ FH-40G survey meter. Experiments involved a water tank phantom (60 × 30 × 30 cm{sup 3}) representing the patient that was uniformly irradiated using a 3 mm spot diameter proton pencil beam with 10 cm modulation width, 19.95 cm distal beam range, and 10 × 10 cm{sup 2} field size. Results: Neutron spectrometry around the target volume showed two main components at the thermal and fast energy ranges. The study also revealed the large dependence of the energy distribution of neutrons, and consequently of out-of-field doses, on the primary beam direction (directional emission of intranuclear cascade neutrons) and energy (spectral composition of secondary neutrons). In addition, neutron mapping within the facility was conducted and showed the highest H{sup ∗}(10) value of ∼51 μSv Gy{sup −1}; this was measured at 1.15 m along the beam axis. H{sup ∗}(10) values

  1. A comparison of HDR near source dosimetry using a treatment planning system, Monte Carlo simulation, and radiochromic film

    SciTech Connect

    Amoush, Ahmad; Luckstead, Marcus; Lamba, Michael; Elson, Howard; Kassing, William

    2013-07-01

    This study aimed to investigate the high-dose rate Iridium-192 brachytherapy, including near source dosimetry, of a catheter-based applicator from 0.5 mm to 1 cm along the transverse axis. Radiochromic film and Monte Carlo (MC) simulation were used to generate absolute dose for the catheter-based applicator. Results from radiochromic film and MC simulation were compared directly to the treatment planning system (TPS) based on the American Association of Physicists in Medicine Updated Task Group 43 (TG-43U1) dose calculation formalism. The difference between dose measured using radiochromic film along the transverse plane at 0.5 mm from the surface and the predicted dose by the TPS was 24%±13%. The dose difference between the MC simulation along the transverse plane at 0.5 mm from the surface and the predicted dose by the TPS was 22.1%±3%. For distances from 1.5 mm to 1 cm from the surface, radiochromic film and MC simulation agreed with TPS within an uncertainty of 3%. The TPS under-predicts the dose at the surface of the applicator, i.e., 0.5 mm from the catheter surface, as compared to the measured and MC simulation predicted dose. MC simulation results demonstrated that 15% of this error is due to neglecting the beta particles and discrete electrons emanating from the sources and not considered by the TPS, and 7% of the difference was due to the photon alone, potentially due to the differences in MC dose modeling, photon spectrum, scoring techniques, and effect of the presence of the catheter and the air gap. Beyond 1 mm from the surface, the TPS dose algorithm agrees with the experimental and MC data within 3%.

  2. Activation Measurements for Thermal Neutrons, U.S. Measurements of 36Cl in Mineral Samples from Hiroshima and Nagasaki; and Measurement of 63 Ni in Copper Samples From Hiroshima by Accelerator Mass Spectrometry

    SciTech Connect

    Tore Straume; Alfredo A. Marchetti; Stephen D. Egbert; James A. Roberts; Ping Men; Shoichiro Fujita; Kiyoshi Shizuma; Masaharu Hoshi; G. Rugel; W. Ruhm; G. Korschinek; J. E. McAninch; K. L. Carroll; T. Faestermann; K. Knie; R. E. Martinelli; A. Wallner; C. Wallner

    2005-01-14

    The present paper presents the {sup 36}Cl measurement effort in the US. A large number of {sup 36}Cl measurements have been made in both granite and concrete samples obtained from various locations and distances in Hiroshima and Nagasaki. These measurements employed accelerator mass spectrometry (AMS) to quantify the number of atoms of {sup 36}Cl per atom of total Cl in the sample. Results from these measurements are presented here and discussed in the context of the DS02 dosimetry reevaluation effort for Hiroshima and Nagasaki atomic-bomb survivors. The production of {sup 36}Cl by bomb neutrons in mineral samples from Hiroshima and Nagasaki was primarily via the reaction {sup 35}Cl(n,{gamma}){sup 36}Cl. This reaction has a substantial thermal neutron cross-section (43.6 b at 0.025 eV) and the product has a long half-life (301,000 y). hence, it is well suited for neutron-activation detection in Hiroshima and Nagasaki using AMS more than 50 years after the bombings. A less important reaction for bomb neutrons, {sup 39}K(n,{alpha}){sup 36}Cl, typically produces less than 10% of the {sup 36}Cl in mineral samples such as granite and concrete, which contain {approx} 2% potassium. In 1988, only a year after the publication of the DS86 final report (Roesch 1987), it was demonstrated experimentally that {sup 36}Cl measured using AMS should be able to detect the thermal neutron fluences at the large distances most relevant to the A-bomb survivor dosimetry. Subsequent measurements in mineral samples from both Hiroshima and Nagasaki validated the experimental findings. The potential utility of {sup 36}Cl as a thermal neutron detector in Hiroshima was first presented by Haberstock et al. who employed the Munich AMS facility to measure {sup 36}Cl/Cl ratios in a gravestone from near the hypocenter. That work subsequently resulted in an expanded {sup 36}Cl effort in Germany that paralleled the US work. More recently, there have also been {sup 36}Cl measurements made by a Japanese

  3. Measurement of absorbed dose to water around an electronic brachytherapy source. Comparison of two dosimetry systems: lithium formate EPR dosimeters and radiochromic EBT2 film

    NASA Astrophysics Data System (ADS)

    Adolfsson, Emelie; White, Shane; Landry, Guillaume; Lund, Eva; Gustafsson, Håkan; Verhaegen, Frank; Reniers, Brigitte; Carlsson Tedgren, Åsa; Alm Carlsson, Gudrun

    2015-05-01

    Interest in high dose rate (HDR) electronic brachytherapy operating at 50 kV is increasing. For quality assurance it is important to identify dosimetry systems that can measure the absorbed doses in absolute terms which is difficult in this energy region. In this work a comparison is made between two dosimetry systems, EPR lithium formate dosimeters and radiochromic EBT2 film. Both types of dosimeters were irradiated simultaneously in a PMMA phantom using the Axxent EBS. Absorbed dose to water was determined at distances of 10 mm, 30 mm and 50 mm from the EBS. Results were traceable to different primary standards as regards to absorbed dose to water (EPR) and air kerma (EBT2). Monte Carlo simulations were used in absolute terms as a third estimate of absorbed dose to water. Agreement within the estimated expanded (k = 2) uncertainties (5% (EPR), 7% (EBT2)) was found between the results at 30 mm and 50 mm from the x-ray source. The same result was obtained in 4 repetitions of irradiation, indicating high precision in the measurements with both systems. At all distances, agreement between EPR and Monte Carlo simulations was shown as was also the case for the film measurements at 30mm and 50mm. At 10mm the geometry for the film measurements caused too large uncertainty in measured values depending on the exact position (within sub-mm distances) of the EBS and the 10 mm film results were exculded from comparison. This work has demonstrated good performance of the lithium formate EPR dosimetry system in accordance with earlier experiments at higher photon energies (192Ir HDR brachytherapy). It was also highlighted that there might be issues regarding the energy dependence and intrinsic efficiency of the EBT2 film that need to be considered for measurements using low energy sources.

  4. Thin film tritium dosimetry

    DOEpatents

    Moran, Paul R.

    1976-01-01

    The present invention provides a method for tritium dosimetry. A dosimeter comprising a thin film of a material having relatively sensitive RITAC-RITAP dosimetry properties is exposed to radiation from tritium, and after the dosimeter has been removed from the source of the radiation, the low energy electron dose deposited in the thin film is determined by radiation-induced, thermally-activated polarization dosimetry techniques.

  5. Protein variants in Hiroshima and Nagasaki: tales of two cities.

    PubMed Central

    Neel, J V; Satoh, C; Smouse, P; Asakawa, J; Takahashi, N; Goriki, K; Fujita, M; Kageoka, T; Hazama, R

    1988-01-01

    The results of 1,465,423 allele product determinations based on blood samples from Hiroshima and Nagasaki, involving 30 different proteins representing 32 different gene products, are analyzed in a variety of ways, with the following conclusions: (1) Sibships and their parents are included in the sample. Our analysis reveals that statistical procedures designed to reduce the sample to equivalent independent genomes do not in population comparisons compensate for the familial cluster effect of rare variants. Accordingly, the data set was reduced to one representative of each sibship (937,427 allele products). (2) Both chi 2-type contrasts and a genetic distance measure (delta) reveal that rare variants (P less than .01) are collectively as effective as polymorphisms in establishing genetic differences between the two cities. (3) We suggest that rare variants that individually exhibit significant intercity differences are probably the legacy of tribal private polymorphisms that occurred during prehistoric times. (4) Despite the great differences in the known histories of the two cities, both the overall frequency of rare variants and the number of different rare variants are essentially identical in the two cities. (5) The well-known differences in locus variability are confirmed, now after adjustment for sample size differences for the various locus products; in this large series we failed to detect variants at only three of 29 loci for which sample size exceeded 23,000. (6) The number of alleles identified per locus correlates positively with subunit molecular weight. (7) Loci supporting genetic polymorphisms are characterized by more rare variants than are loci at which polymorphisms were not encountered. (8) Loci whose products do not appear to be essential for health support more variants than do loci the absence of whose product is detrimental to health. (9) There is a striking excess of rare variants over the expectation under the neutral mutation

  6. BREN Tower: A Monument to the Material Culture of Radiation Dosimetry Research

    SciTech Connect

    Susan Edwards

    2008-05-30

    With a height of more than 1,500 feet, the BREN (Bare Reactor Experiment, Nevada) Tower dominates the surrounding desert landscape of the Nevada Test Site. Associated with the nuclear research and atmospheric testing programs carried out during the 1950s and 1960s, the tower was a vital component in a series of experiments aimed at characterizing radiation fields from nuclear detonations. Research programs conducted at the tower provided the data for the baseline dosimetry studies crucial to determining the radiation dose rates received by the atomic bomb survivors of Hiroshima and Nagasaki, Japan. Today, BREN Tower stands as a monument to early dosimetry research and one of the legacies of the Cold War.

  7. Evaluation of 3D Gamma index calculation implemented in two commercial dosimetry systems

    NASA Astrophysics Data System (ADS)

    Xing, Aitang; Arumugam, Sankar; Deshpande, Shrikant; George, Armia; Vial, Philip; Holloway, Lois; Goozee, Gary

    2015-01-01

    3D Gamma index is one of the metrics which have been widely used for clinical routine patient specific quality assurance for IMRT, Tomotherapy and VMAT. The algorithms for calculating the 3D Gamma index using global and local methods implemented in two software tools: PTW- VeriSoft® as a part of OCTIVIUS 4D dosimeter systems and 3DVHTM from Sun Nuclear were assessed. The Gamma index calculated by the two systems was compared with manual calculated for one data set. The Gamma pass rate calculated by the two systems was compared using 3%/3mm, 2%/2mm, 3%/2mm and 2%/3mm for two additional data sets. The Gamma indexes calculated by the two systems were accurate, but Gamma pass rates calculated by the two software tools for same data set with the same dose threshold were different due to the different interpolation of raw dose data by the two systems and different implementation of Gamma index calculation and other modules in the two software tools. The mean difference was -1.3%±3.38 (1SD) with a maximum difference of 11.7%.

  8. SU-E-T-586: Optimal Determination of Tolerance Level for Radiation Dose Delivery Verification in An in Vivo Dosimetry System

    SciTech Connect

    Chen, Y; Souri, S; Gill, G; Rea, A; Kuruvilla, A; Riegel, A; Cao, Y; Jamshidi, A

    2015-06-15

    Purpose: To statistically determine the optimal tolerance level in the verification of delivery dose compared to the planned dose in an in vivo dosimetry system in radiotherapy. Methods: The LANDAUER MicroSTARii dosimetry system with screened nanoDots (optically stimulated luminescence dosimeters) was used for in vivo dose measurements. Ideally, the measured dose should match with the planned dose and falls within a normal distribution. Any deviation from the normal distribution may be redeemed as a mismatch, therefore a potential sign of the dose misadministration. Randomly mis-positioned nanoDots can yield a continuum background distribution. A percentage difference of the measured dose to its corresponding planned dose (ΔD) can be used to analyze combined data sets for different patients. A model of a Gaussian plus a flat function was used to fit the ΔD distribution. Results: Total 434 nanoDot measurements for breast cancer patients were collected across a period of three months. The fit yields a Gaussian mean of 2.9% and a standard deviation (SD) of 5.3%. The observed shift of the mean from zero is attributed to the machine output bias and calibration of the dosimetry system. A pass interval of −2SD to +2SD was applied and a mismatch background was estimated to be 4.8%. With such a tolerance level, one can expect that 99.99% of patients should pass the verification and at most 0.011% might have a potential dose misadministration that may not be detected after 3 times of repeated measurements. After implementation, a number of new start breast cancer patients were monitored and the measured pass rate is consistent with the model prediction. Conclusion: It is feasible to implement an optimal tolerance level in order to maintain a low limit of potential dose misadministration while still to keep a relatively high pass rate in radiotherapy delivery verification.

  9. Utilizing a simple CT dosimetry phantom for the comprehension of the operational characteristics of CT AEC systems

    SciTech Connect

    Tsalafoutas, Ioannis A.; Varsamidis, Athanasios; Thalassinou, Stella; Efstathopoulos, Efstathios P.

    2013-11-15

    Purpose: To investigate the utility of the nested polymethylacrylate (PMMA) phantom (which is available in many CT facilities for CTDI measurements), as a tool for the presentation and comparison of the ways that two different CT automatic exposure control (AEC) systems respond to a phantom when various scan parameters and AEC protocols are modified.Methods: By offsetting the two phantom's components (the head phantom and the body ring) half-way along their longitudinal axis, a phantom with three sections of different x-ray attenuation was created. Scan projection radiographs (SPRs) and helical scans of the three-section phantom were performed on a Toshiba Aquilion 64 and a Philips Brilliance 64 CT scanners, with different scan parameter selections [scan direction, pitch factor, slice thickness, and reconstruction interval (ST/RI), AEC protocol, and tube potential used for the SPRs]. The dose length product (DLP) values of each scan were recorded and the tube current (mA) values of the reconstructed CT images were plotted against the respective Z-axis positions on the phantom. Furthermore, measurements of the noise levels at the center of each phantom section were performed to assess the impact of mA modulation on image quality.Results: The mA modulation patterns of the two CT scanners were very dissimilar. The mA variations were more pronounced for Aquilion 64, where changes in any of the aforementioned scan parameters affected both the mA modulations curves and DLP values. However, the noise levels were affected only by changes in pitch, ST/RI, and AEC protocol selections. For Brilliance 64, changes in pitch affected the mA modulation curves but not the DLP values, whereas only AEC protocol and SPR tube potential selection variations affected both the mA modulation curves and DLP values. The noise levels increased for smaller ST/RI, larger weight category AEC protocol, and larger SPR tube potential selection.Conclusions: The nested PMMA dosimetry phantom can be

  10. Measurement of differential proton spectra onboard the Space Shuttle using a thermoluminescent dosimetry system

    NASA Technical Reports Server (NTRS)

    Richmond, R. G.; Badhwar, G. D.; Cash, B.; Atwell, W.; Hardy, A. C. (Principal Investigator)

    1987-01-01

    An experimental technique that permits the extraction of orbit-averaged, differential energy spectra of trapped radiation belt protons using simple passive detectors is described. An inversion technique is used for the data analysis. The basic principle of the described system is measurement of the energy deposited in six thermoluminescent (TLD) detector assemblies behind various spherical absorbers. The technique has been applied to a detector assembly flown on four Shuttle flights. Although severe restraints were placed on the flight package, the differential energy spectra derived from these measurements are in good agreement with analytical results using a modified trapped proton environment model. The technique shows good promise for measuring the spectra in low inclination orbits where the flux of high energy galactic cosmic rays protons is small. Modifications to the detector assembly to improve the accuracy and to extend the range of the system to higher energies are suggested.

  11. Feasibility study of SPECT system for online dosimetry imaging in boron neutron capture therapy.

    PubMed

    Hales, B; Katabuchi, T; Hayashizaki, N; Terada, K; Igashira, M; Kobayashi, T

    2014-06-01

    A single collimator version of a proposed PG-SPECT system was manufactured and experimentally tested. Combining this experimental data with Monte Carlo simulation, the viability of Ge and CdTe semiconductors detectors was calculated. It was determined that the best detector of the ones compared would be a CdTe detector of 2-3mm, aided by the benefit of adding a Compton-suppression anti-coincidence timing detector. PMID:24378365

  12. Development and initial characterization of a nuclear magnetic resonance dosimetry system

    SciTech Connect

    Thomasson, D.M.

    1990-01-01

    A novel high dose radiation dosimeter was developed employing NMR spectroscopic quantitation of the radiolytic products of methanol. Chemical shifts of product resonances relative to the solvent allow quantification using NMR techniques. Due to expected dynamic range limitations of NMR instrumentation, deuterated methanol is used with a presaturation suppression sequence to reduce the solvent proton signals. Methanol's {sup 13}C-coupled proton resonances is used as an internal reference to normalize product signals otherwise subject to spectrometer variability. Data on reproducibility, dose response, and temporal stability were acquired. System reproducibility for a sample at 1 kGy is {approx}10%. The dose response is linear in the range between 200 Gy and 50 kGy. No significant signal degradation was observed during a six month period. Advantages of this type dosimeter system include ease of use, large dynamic range, and temporal stability. An additional characteristic of a methanol based system is the LET dependent response in the chemical yields of formaldehyde and ethylene glycol. 70 refs., 15 figs., 9 tabs.

  13. Dosimetry for infant exposures to electronic article surveillance system: posture, physical dimension and anatomy.

    PubMed

    Li, Congsheng; Wu, Tongning

    2015-04-01

    The use of electronic article surveillance (EAS) systems has become popular in many public sites. As a consequence, concern has risen about infant exposure to magnetic fields (MFs) from this kind of device. To evaluate infant exposure to MFs of an EAS system (operating at 125 kHz and 13.56 MHz), we numerically compared dosimetric results among adult, child and infant models. Results revealed that postures insignificantly influenced dosimetric results if there was a similar cross-sectional area under exposure. Although safety limits are unlikely to be exceeded, the infant has higher SAR values for brain and central nervous system tissues compared with adult (1.5x at 125 kHz and 112x at 13.56 MHz), which deserve further investigation. Infant's specific anatomy (e.g., non-proportionally large head and high fat content) did not induce higher SAR values. The numerical models developed in the study (stroller and postured infant models) could be freely used for nonprofit academic research. PMID:25756750

  14. DOSEXPRT: A bioassay dosimetry code for Martin Marietta Energy Systems, Inc.

    SciTech Connect

    Ward, R.C.; Eckerman, K.F.

    1992-04-01

    The bioassay code DOSEXPRT was developed for Martin Marietta Energy Systems, Inc., to provide compliance with Department of Energy (DOE) Order 5480, Chapter 11. DOSEXPRT computes the intake of a radionuclide in any year (considering both acute and chronic intakes) from in vivo measurements of the retained activity and/or measurements of the activity in excreta. The committed effective and organ doses for the intake are computed as well as the effective and organ doses expected to be received in each calendar year out to 50 years beyond the year of intake. The bioassay records used as input for DOSEXPRT are extracted from the Martin Marietta Energy Systems Occupational Health Information System (OHIS). DOSEXPRT implements a set of algorithms with parameters governing the translocation, retention, and excretion of the nuclide contained in data files specific to the nuclide. These files also contain dose-per-unit-intake coefficients used to compute the committed dose equivalent for the intakes in the year. Annual organ and effective doses are computed using additional dose-rate files that contain data on the dose rate at various times following a unit intake. If measurements are presented for more than one assay for a given nuclide, DOSEXPRT estimates the intake by applying weights assigned in the nuclide file for each assay. DOSEXPRT is accessed off the OHIS MENU No. 4 and designed to be run as a batch processor, but can also be run interactively for testing purposes.

  15. DOSEXPRT: A bioassay dosimetry code for Martin Marietta Energy Systems, Inc

    SciTech Connect

    Ward, R.C.; Eckerman, K.F.

    1992-04-01

    The bioassay code DOSEXPRT was developed for Martin Marietta Energy Systems, Inc., to provide compliance with Department of Energy (DOE) Order 5480, Chapter 11. DOSEXPRT computes the intake of a radionuclide in any year (considering both acute and chronic intakes) from in vivo measurements of the retained activity and/or measurements of the activity in excreta. The committed effective and organ doses for the intake are computed as well as the effective and organ doses expected to be received in each calendar year out to 50 years beyond the year of intake. The bioassay records used as input for DOSEXPRT are extracted from the Martin Marietta Energy Systems Occupational Health Information System (OHIS). DOSEXPRT implements a set of algorithms with parameters governing the translocation, retention, and excretion of the nuclide contained in data files specific to the nuclide. These files also contain dose-per-unit-intake coefficients used to compute the committed dose equivalent for the intakes in the year. Annual organ and effective doses are computed using additional dose-rate files that contain data on the dose rate at various times following a unit intake. If measurements are presented for more than one assay for a given nuclide, DOSEXPRT estimates the intake by applying weights assigned in the nuclide file for each assay. DOSEXPRT is accessed off the OHIS MENU No. 4 and designed to be run as a batch processor, but can also be run interactively for testing purposes.

  16. Emerging technological bases for retrospective dosimetry.

    PubMed

    Straume, T; Anspaugh, L R; Haskell, E H; Lucas, J N; Marchetti, A A; Likhtarev, I A; Chumak, V V; Romanyukha, A A; Khrouch, V T; Gavrilin YuI; Minenko, V F

    1997-01-01

    In this article we discuss examples of challenging problems in retrospective dosimetry and describe some promising solutions. The ability to make measurements by accelerator mass spectrometry and luminescence techniques promises to provide improved dosimetry for regions of Belarus, Ukraine and Russian Federation contaminated by radionuclides from the Chernobyl accident. In addition, it may soon be possible to resolve the large neutron discrepancy in the dosimetry system for Hiroshima through novel measurement techniques that can be used to reconstruct the fast-neutron fluence emitted by the bomb some 51 years ago. Important advances in molecular cytogenetics and electron paramagnetic resonance measurements have produced biodosimeters that show potential in retrospective dosimetry. The most promising of these are the frequency of reciprocal translocations measured in chromosomes of blood lymphocytes using fluorescence in situ hybridization and the electron paramagnetic resonance signal in tooth enamel. PMID:9368303

  17. Medical dosimetry in Hungary

    NASA Astrophysics Data System (ADS)

    Turák, O.; Osvay, M.; Ballay, L.

    2012-09-01

    Radiation exposure of medical staff during cardiological and radiological procedures was investigated. The exposure of medical staff is directly connected to patient exposure. The aim of this study was to determine the distribution of doses on uncovered part of body of medical staff using LiF thermoluminescent (TL) dosimeters in seven locations. Individual Kodak film dosimeters (as authorized dosimetry system) were used for the assessment of medical staff's effective dose. Results achieved on dose distribution measurements confirm that wearing only one film badge under the lead apron does not provide enough information on the personal dose. The value of estimated annual doses on eye lens and extremities (fingers) were in good correlation with international publications.

  18. International Reactor Dosimetry Data.

    Energy Science and Technology Software Center (ESTSC)

    1982-06-28

    Version 00 IRDF-82 contains 620 neutron group cross sections (SAND-II format) based on the ENDF/B-V Special Purpose Dosimetry File as well as other reaction cross sections important for dosimetry applications. In addition, multigroup spectra for ten reference benchmarks are also provided.

  19. Applicability of ACR breast dosimetry methodology to a digital mammography system

    SciTech Connect

    Tomon, John J.; Johnson, Thomas E.; Swenson, Kristin N.; Schauer, David A.

    2006-03-15

    Determination of mean glandular dose (MGD) to breast tissue is an essential aspect of mammography equipment evaluations and exposure controls. The American College of Radiology (ACR) Quality Control Manual outlines the procedure for MGD determination in screen-film mammography based upon conversions of entrance skin exposures (ESEs) measured with an ionization chamber (IC). The development of digital mammography has increased with the demand for improved object resolution and tissue contrast. This change in image receptor from screen-film to a solid-state detector has led to questions about the applicability of the ACR MGD methodology to digital mammography. This research has validated the applicability of the ACR MGD methodology to digital mammography in the GE digital mammography system Senographe 2000D[reg]. MGD was determined using light output measurements from thermoluminescent dosimeters (MGD{sub TL}), exposure measurements from an IC (MGD{sub IC}) and conversion factors from the ACR Mammography Quality Control Manual. MGD{sub TL} and MGD{sub IC} data indicate that there is a statistically significant difference between the two measurements with the Senographe 2000D[reg]. However, the applicability of the ACR's methodology was validated by calculating MGD at various depths in a 50/50 breast phantom. Additionally, the results of backscatter measurements from the image receptors of both mammography modalities indicate there is a difference (all P values <0.001) in the radiation backscattered from each image receptor.

  20. Dosimetry of an In-Line Kilovoltage Imaging System and Implementation in Treatment Planning

    SciTech Connect

    Dzierma, Yvonne; Alaei, Parham; Licht, Norbert; Rübe, Christian

    2014-03-15

    Purpose: To present the beam properties of the Siemens 70-kV and 121-kV linear accelerator-mounted imaging modalities and commissioning of the 121-kV beam in the Philips Pinnacle treatment planning system (TPS); measurements in an Alderson phantom were performed for verification of the model and to estimate the cone-beam CT (CBCT) imaging dose in the head and neck, thorax, and pelvis. Methods and Materials: The beam profiles and depth–dose curve were measured in an acrylic phantom using thermoluminescent dosimeters and a soft x-ray ionization chamber. Measurements were imported into the TPS, modeled, and verified by phantom measurements. Results: Modeling of the profiles and the depth–dose curve can be achieved with good quality. Comparison with the measurements in the Alderson phantom is generally good; only very close to bony structures is the dose underestimated by the TPS. For a 200° arc CBCT of the head and neck, a maximum dose of 7 mGy is measured; the thorax and pelvis 360° CBCTs give doses of 4-10 mGy and 7-15 mGy, respectively. Conclusions: Dosimetric characteristics of the Siemens kVision imaging modalities are presented and modeled in the Pinnacle TPS. Thermoluminescent dosimeter measurements in the Alderson phantom agree well with the calculated TPS dose, validating the model and providing an estimate of the imaging dose for different protocols.

  1. Hanford External Dosimetry Technical Basis Manual PNL-MA-842

    SciTech Connect

    Rathbone, Bruce A.

    2005-02-25

    The Hanford External Dosimetry Technical Basis Manual PNL-MA-842 documents the design and implementation of the external dosimetry system used at Hanford. The manual describes the dosimeter design, processing protocols, dose calculation methodology, radiation fields encountered, dosimeter response characteristics, limitations of dosimeter design under field conditions, and makes recommendations for effective use of the dosimeters in the field. The manual describes the technical basis for the dosimetry system in a manner intended to help ensure defensibility of the dose of record at Hanford and to demonstrate compliance with 10 CFR 835, DOELAP, DOE-RL, ORP, PNSO, and Hanford contractor requirements. The dosimetry system is operated by PNNL’s Hanford External Dosimetry Program which provides dosimetry services to all Hanford contractors. The primary users of this manual are DOE and DOE contractors at Hanford using the dosimetry services of PNNL. Development and maintenance of this manual is funded directly by DOE and DOE contractors. Its contents have been reviewed and approved by DOE and DOE contractors at Hanford through the Hanford Personnel Dosimetry Advisory Committee which is chartered and chaired by DOE-RL and serves as means of coordinating dosimetry practices across contractors at Hanford. This manual was established in 1996. Since inception, it has been revised many times and maintained by PNNL as a controlled document with controlled distribution. Rev. 0 marks the first revision to be released through PNNL’s Electronic Records & Information Capture Architecture (ERICA) database.

  2. Applications of nuclear data in human radiation dosimetry

    SciTech Connect

    Kerr, G.D.; Eckerman, K.F. )

    1991-01-01

    Individuals are exposed to ionizing radiations in two ways: from radiation sources external to the body or from internal sources. In either case, the magnitude of the radiation dose to the sensitive tissues of the body is of primary concern. Radiation dose (or absorbed dose) is a physical quantity defined as the amount of ionizing energy absorbed per unit mass of material. For radiation protection purposes, however, it is also necessary to use the dose equivalent, which includes modifiers of absorbed dose to more fully reflect the biological considerations associated with different ionizing radiations. A research group at Oak Ridge National Laboratory has focused on defining the exposure-dose relationship (i.e., the relationship between radiation exposure from internal or external sources and the radiation dose received by tissues of the body). Although radiation can be readily detected and measured, it is not feasible to make direct measurements of the dose within the organs and tissues of the body. Nuclear data have been extensively used in these studies but improvements are needed in the current nuclear data base. Examples of these applications include studies dealing with (a) the application of the recommendations of Publication 26 of the International Committee on Radiological Protection in the dosimetry of internally deposited radionuclides and (b) the reassessment of radiation dosimetry for the atomic bombs in Hiroshima and Nagasaki.

  3. Practical CT dosimetry

    SciTech Connect

    Yoshizumi, T.T.; Suneja, S.K.; Teal, J.S. )

    1989-07-01

    The dose from computed tomography (CT) examinations is not negligible from a radiation safety standpoint. Occasionally, one encounters a case in which an unsuspected pregnant woman undergoes a CT pelvic scan, and the radiologist is required to estimate the dose to the fetus. This article addresses practical methods of CT dosimetry with a specific discussion on fetal dose estimate. Three methods are described: (1) the use of a dose chart, (2) the pencil ionization chamber method, and (3) the thermoluminescence dosimetry (TLD) method.

  4. Czech results at criticality dosimetry intercomparison 2002.

    PubMed

    Frantisek, Spurný; Jaroslav, Trousil

    2004-01-01

    Two criticality dosimetry systems were tested by Czech participants during the intercomparison held in Valduc, France, June 2002. The first consisted of the thermoluminescent detectors (TLDs) (Al-P glasses) and Si-diodes as passive neutron dosemeters. Second, it was studied to what extent the individual dosemeters used in the Czech routine personal dosimetry service can give a reliable estimation of criticality accident exposure. It was found that the first system furnishes quite reliable estimation of accidental doses. For routine individual dosimetry system, no important problems were encountered in the case of photon dosemeters (TLDs, film badge). For etched track detectors in contact with the 232Th or 235U-Al alloy, the track density saturation for the spark counting method limits the upper dose at approximately 1 Gy for neutrons with the energy >1 MeV. PMID:15353690

  5. Persistence of Neutralizing Antibody Against Dengue Virus 2 After 70 Years from Infection in Nagasaki

    PubMed Central

    Ngwe Tun, Mya Myat; Muta, Yoshihito; Inoue, Shingo; Morita, Kouichi

    2016-01-01

    Abstract This study aimed to investigate the duration of humoral immune responses to dengue virus (DENV) infection in Japanese who experienced acute febrile illness with hemorrhagic manifestations 70 years ago, when an epidemic of dengue occurred in Nagasaki, Japan, from 1942 to 1944. A Japanese volunteer requested serological diagnosis of DENV infection in 2014 and donated blood sample to measure the antibody titer against DENV by antiflavi IgG indirect ELISA, focus reduction neutralization test, and plaque reduction neutralization test. The serum sample of the volunteer was positive in flavi IgG ELISA and it indicated primary infection. In the neutralization test, the highest neutralizing titer was ≥218 for DENV-2. We report here the existence of DENV-specific antibodies in the serum of a person after 70 years from infection. Published reports indicated that DENV-1 was responsible for the 1942–1944 outbreak in Nagasaki. However, our data suggested that DENV-2 also played a role in this Nagasaki dengue epidemic. PMID:27493841

  6. Persistence of Neutralizing Antibody Against Dengue Virus 2 After 70 Years from Infection in Nagasaki.

    PubMed

    Ngwe Tun, Mya Myat; Muta, Yoshihito; Inoue, Shingo; Morita, Kouichi

    2016-01-01

    This study aimed to investigate the duration of humoral immune responses to dengue virus (DENV) infection in Japanese who experienced acute febrile illness with hemorrhagic manifestations 70 years ago, when an epidemic of dengue occurred in Nagasaki, Japan, from 1942 to 1944. A Japanese volunteer requested serological diagnosis of DENV infection in 2014 and donated blood sample to measure the antibody titer against DENV by antiflavi IgG indirect ELISA, focus reduction neutralization test, and plaque reduction neutralization test. The serum sample of the volunteer was positive in flavi IgG ELISA and it indicated primary infection. In the neutralization test, the highest neutralizing titer was ≥218 for DENV-2. We report here the existence of DENV-specific antibodies in the serum of a person after 70 years from infection. Published reports indicated that DENV-1 was responsible for the 1942-1944 outbreak in Nagasaki. However, our data suggested that DENV-2 also played a role in this Nagasaki dengue epidemic. PMID:27493841

  7. Survey of international personnel radiation dosimetry programs

    SciTech Connect

    Swaja, R.E.

    1985-04-01

    In September of 1983, a mail survey was conducted to determine the status of external personnel gamma and neutron radiation dosimetry programs at international agencies. A total of 130 agencies participated in this study including military, regulatory, university, hospital, laboratory, and utility facilities. Information concerning basic dosimeter types, calibration sources, calibration phantoms, corrections to dosimeter responses, evaluating agencies, dose equivalent reporting conventions, ranges of typical or expected dose equivalents, and degree of satisfaction with existing systems was obtained for the gamma and neutron personnel monitoring programs at responding agencies. Results of this survey indicate that to provide the best possible occupational radiation monitoring programs and to improve dosimetry accuracy in performance studies, facility dosimetrists, regulatory and standards agencies, and research laboratories must act within their areas of responsibility to become familiar with their radiation monitoring systems, establish common reporting guidelines and performance standards, and provide opportunities for dosimetry testing and evaluation. 14 references, 10 tables.

  8. I-123 - FP-CIT pharmacokinetics and dosimetry show great potential for the evaluation of dopamine transporter system in clinical routine

    SciTech Connect

    Costa, D.C.; Walker, S.; Waddington, W. |

    1996-05-01

    FP-CIT is a N-fluoropropyl analogue of the [2{beta}-carbomethoxy-3{beta}-(4-iodophenyl)tropane] which has been labelled with I-123 and developed as a new marker of the pre-synaptic dopamine transporter system. Its selective uptake in the striatum of non-human primates and human volunteers has been reported with advantageous faster brain kinetics than {beta}-CIT. In this pilot work we studied the whole body imaging kinetics of FP-CIT in one normal volunteer - NV (5, 60, 100, 360 minutes and 24 hours post-injection for 20 minutes each) and a drug-free patient with well established Parkinson`s disease - PD (100 minutes) after intravenous injection of 111 MBq. Both subjects had high resolution brain SPECT at 35 minutes and 3.5 hours post-injection. Percent of whole body uptake (geometric mean of anterior and posterior projections) in different organs, including total brain and basal ganglia shows rapid clearance from blood during the first hour with no significant change from 100 minutes to 24 hours. The basal ganglia uptake is approximately 0.4% of total body from 100 minutes onwards. Striatal uptake (ratio to frontal cortex) is different between subjects, mainly at 3.5 hours and more marked in the putamen: Calculated dosimetry (mSv/MBq) showed E.D.E.-0.034, and total doses to whole body - 0.01, total brain - 0.017, basal ganglia - 0.155, small intestine - 0.06, urinary bladder - 0.05 and liver - 0.03. These data confirm that FP-CIT has acceptable dosimetry with good pharmacokinetics enabling the study of pre-synaptic dopamine transport system in nigrostriatal degeneration with clinical SPECT at 3-4 hrs p.i.

  9. Investigation of a MOSFET dosimetry system for midpoint dose verification in prostate 3D CRT/IMRT.

    PubMed

    Wiese, T; Bezak, E; Nelligan, R

    2008-09-01

    The suitability of MOSFETs (Metal Oxide Semiconductor Field Effect Transistors) for use in in-vivo dosimetry for IMRT prostate treatment and patient setup errors has been investigated in this work. MOSFETs were placed on entrance and exit surfaces of a number of different phantoms (with varying complexities from homogeneous to anthropomorphic). Dose measurements were then used to calculate a midpoint dose, which was compared with an IC placed at the isocentre. The agreements found between the calculated (MOSFETs) and the measured midpoint dose (IC) was: 0.7% for a prostate treatment verification and 3.5% for an IMRT treatment. MOSFETs placed on entry and exit surfaces can detect patient setup offsets of 2 cm, but do not have the sensitivity to confidently detect offsets of 1 cm or smaller. PMID:18946975

  10. Characterization of calibration curves and energy dependence GafChromic{sup TM} XR-QA2 model based radiochromic film dosimetry system

    SciTech Connect

    Tomic, Nada Quintero, Chrystian; Aldelaijan, Saad; Bekerat, Hamed; Liang, LiHeng; DeBlois, François; Devic, Slobodan; Whiting, Bruce R.; Seuntjens, Jan

    2014-06-15

    Purpose: The authors investigated the energy response of XR-QA2 GafChromic{sup TM} film over a broad energy range used in diagnostic radiology examinations. The authors also made an assessment of the most suitable functions for both reference and relative dose measurements. Methods: Pieces of XR-QA2 film were irradiated to nine different values of air kerma in air, following reference calibration of a number of beam qualities ranging in HVLs from 0.16 to 8.25 mm Al, which corresponds to effective energy range from 12.7 keV to 56.3 keV. For each beam quality, the authors tested three functional forms (rational, linear exponential, and power) to assess the most suitable function by fitting the delivered air kerma in air as a function of film response in terms of reflectance change. The authors also introduced and tested a new parameterχ = netΔR·e{sup m} {sup netΔR} that linearizes the inherently nonlinear response of the film. Results: The authors have found that in the energy range investigated, the response of the XR-QA2 based radiochromic film dosimetry system ranges from 0.222 to 0.420 in terms of netΔR at K{sub air}{sup air} = 8 cGy. For beam qualities commonly used in CT scanners (4.03–8.25 mm Al), the variation in film response (netΔR at K{sub air}{sup air} = 8 cGy) amounts to ± 5%, while variation in K{sub air}{sup air} amounts to ± 14%. Conclusions: Results of our investigation revealed that the use of XR-QA2 GafChromic{sup TM} film is accompanied by a rather pronounced energy dependent response for beam qualities used for x-ray based diagnostic imaging purposes. The authors also found that the most appropriate function for the reference radiochromic film dosimetry would be the power function, while for the relative dosimetry one may use the exponential response function that can be easily linearized.

  11. Renal Shielding and Dosimetry for Patients With Severe Systemic Sclerosis Receiving Immunoablation With Total Body Irradiation in the Scleroderma: Cyclophosphamide or Transplantation Trial

    SciTech Connect

    Craciunescu, Oana I.; Steffey, Beverly A.; Kelsey, Chris R.; Larrier, Nicole A.; Paarz-Largay, Cathy J.; Prosnitz, Robert G.; Chao, Nelson; Chute, John; Gasparetto, Cristina; Horwitz, Mitchell; Long, Gwynn; Rizzieri, David; Sullivan, Keith M.

    2011-03-15

    Purpose: To describe renal shielding techniques and dosimetry in delivering total body irradiation (TBI) to patients with severe systemic sclerosis (SSc) enrolled in a hematopoietic stem cell transplant protocol. Methods and Materials: The Scleroderma: Cyclophosphamide or Transplantation (SCOT) protocol uses a lymphoablative preparative regimen including 800 cGy TBI delivered in two 200-cGy fractions twice a day before CD34{sup +} selected autologous hematopoietic stem cell transplantation. Lung and kidney doses are limited to 200 cGy to protect organs damaged by SSc. Kidney block proximity to the spinal cord was investigated, and guidelines were developed for acceptable lumbar area TBI dosing. Information about kidney size and the organ shifts from supine to standing positions were recorded using diagnostic ultrasound (US). Minimum distance between the kidney blocks (dkB) and the lumbar spine region dose was recorded, and in vivo dosimetry was performed at several locations to determine the radiation doses delivered. Results: Eleven patients were treated at our center with an anteroposterior (AP)/posteroanterior (PA) TBI technique. A 10% to 20% dose inhomogeneity in the lumbar spine region was achieved with a minimum kidney block separation of 4 to 5 cm. The average lumbar spine dose was 179.6 {+-} 18.1 cGy, with an average dkB of 5.0 {+-} 1.0 cm. Kidney block shield design was accomplished using a combination of US and noncontrast computerized tomography (CT) or CT imaging alone. The renal US revealed a wide range of kidney displacement from upright to supine positions. Overall, the average in vivo dose for the kidney prescription point was 193.4 {+-} 5.1 cGy. Conclusions: The dose to the kidneys can be attenuated while maintaining a 10% to 20% dose inhomogeneity in the lumbar spine area. Kidneys were localized more accurately using both US and CT imaging. With this technique, renal function has been preserved, and the study continues to enroll patients.

  12. Renal Shielding and Dosimetry for Patients with Severe Systemic Sclerosis Receiving Immunoablation with Total Body Irradiation on the SCOT (Scleroderma: Cyclophosphamide or Transplantation) Trial

    PubMed Central

    Cracinescu, Oana I.; Steffey, Beverly A.; Kelsey, Chris R.; Larrier, Nicole A.; Paarz-Largay, Cathy J.; Prosnitz, Robert G.; Chao, Nelson; Chute, John; Gasparetto, Cristina; Horwitz, Mitchell; Long, Gwynn; Rizzieri, David; Sullivan, Keith M.

    2010-01-01

    Purpose To describe renal shielding techniques and dosimetry in delivering total body irradiation (TBI) to patients with severe systemic sclerosis (SSc) enrolled on a hematopoietic stem cell transplant protocol. Methods and Materials The SCOT protocol employs a lymphoablative preparative regime including 800cGy TBI delivered in two 200 cGy fractions twice a day before CD34+ selected autologous hematopoietic stem cell transplantation. Lung and kidney dose is limited to 200 cGy to protect organs damaged by SSc. Kidney block proximity to the spinal cord was investigated and guidelines were developed for acceptable lumbar area TBI dosing. Information on kidney size and the organ shifts from supine to standing positions were recorded using diagnostic ultrasound (US). Minimum distance between the kidney blocks (dkB) and the lumbar spine region dose were recorded and in vivo dosimetry was performed at several locations to determine doses of irradiation delivered. Results Eleven patients were treated at our center with an AP/PA TBI technique. A 10–20% dose inhomogeneity in the lumbar spine region was achieved with a minimum kidney block separation of 4–5 cm. The average lumbar spine dose was 179.6 ± 18.1 cGy, with an average dkB of 5.0 ± 1.0 cm. Kidney block shield design was accomplished using a combination of US and non-contrast CT (computerized tomography) or CT imaging alone. The renal US revealed a wide range of kidney displacement from upright to supine positions. Overall, the average in vivo dose for the kidney prescription point was 193.4 ± 5.1 cGy. Conclusions The dose to the kidneys can be attenuated while maintaining a 10–20% dose inhomogeneity in the lumbar spine area. The kidneys were localized more accurately using both US and CT imaging. With this technique, renal function has been preserved and the study continues to enroll. PMID:20800376

  13. Multistage evaluation and commissioning of a pre-calibrated, single-use OneDosePlus MOSFET system for in vivo dosimetry in a radiotherapy department

    PubMed Central

    Lonsdale, A P M

    2012-01-01

    Objectives The aim was to determine the agreement between absorbed dose measurements using the OneDosePlus and treatment planning system calculations in ideal circumstances, minimising patient-related uncertainties, before deciding upon action levels. Methods A OneDose metal oxide semiconductor field-effect transistor (Sicel Technologies, Morrisville, NC) in vivo dosimetry system was subjected to a multistage evaluation that tested standard and non-standard field conditions related to treatment planning system calculations for an anthropomorphic phantom. Results The system was found to perform within manufacturer specifications. Batch uniformity was found to be within specification when measured using a method described by Halvorsen. A modification used to assess statistical distribution of response showed an increase in the value of two standard deviations (2σ) from ±2.3 to ±2.9%, which was still within the manufacturer-stated value of ±5%. The tests using the anthropomorphic phantom also emphasised the fact that patient density inhomogeneities in the region of the Dmax point will affect the dose calculated by the treatment planning system and delivered to the patient. Conclusion The OneDose system does not account for these inhomogeneities, leading to dependence in the deviation between expected and reported dose on inhomogeneity and choice of calculation algorithm. PMID:22045952

  14. Dosimetry procedures for an industrial irradiation plant

    NASA Astrophysics Data System (ADS)

    Grahn, Ch.

    Accurate and reliable dosimetry procedures constitute a very important part of process control and quality assurance at a radiation processing plant. γ-Dose measurements were made on the GBS 84 irradiator for food and other products on pallets or in containers. Chemical dosimeters wre exposed in the facility under conditions of the typical plant operation. The choice of the dosimeter systems employed was based on the experience in chemical dosimetry gained over several years. Dose uniformity information was obtained in air, spices, bulbs, feeds, cosmetics, plastics and surgical goods. Most products currently irradiated require dose uniformity which can be efficiently provided by pallet or box irradiators like GBS 84. The radiation performance characteristics and some dosimetry procedures are discussed.

  15. Solid-State Personal Dosimetry

    NASA Technical Reports Server (NTRS)

    Wrbanek, John D.; Fralick, Gustave C.; Wrbanek, Susan Y.

    2005-01-01

    This document is a web site page, and a data sheet about Personal protection (i.e., space suits) presented to the Radiation and Micrometeoroid Mitigation Technology Focus Group meeting. The website describes the work of the PI to improve solid state personal radiation dosimetry. The data sheet presents work on the active personal radiation detection system that is to provide real-time local radiation exposure information during EVA. Should undue exposure occur, knowledge of the dynamic intensity conditions during the exposure will allow more precise diagnostic assessment of the potential health risk to the exposed individual.

  16. Experimental derivation of relative biological effectiveness of A-bomb neutrons in Hiroshima and Nagasaki and implications for risk assessment.

    PubMed

    Sasaki, M S; Nomura, T; Ejima, Y; Utsumi, H; Endo, S; Saito, I; Itoh, T; Hoshi, M

    2008-07-01

    Epidemiological data on the health effects of A-bomb radiation in Hiroshima and Nagasaki provide the framework for setting limits for radiation risk and radiological protection. However, uncertainty remains in the equivalent dose, because it is generally believed that direct derivation of the relative biological effectiveness (RBE) of neutrons from the epidemiological data on the survivors is difficult. To solve this problem, an alternative approach has been taken. The RBE of polyenergetic neutrons was determined for chromosome aberration formation in human lymphocytes irradiated in vitro, compared with published data for tumor induction in experimental animals, and validated using epidemiological data from A-bomb survivors. The RBE of fission neutrons was dependent on dose but was independent of the energy spectrum. The same RBE regimen was observed for lymphocyte chromosome aberrations and tumors in mice and rats. Used as a weighting factor for A-bomb survivors, this RBE system was superior in eliminating the city difference in chromosome aberration frequencies and cancer mortality. The revision of the equivalent dose of A-bomb radiation using DS02 weighted by this RBE system reduces the cancer risk by a factor of 0.7 compared with the current estimates using DS86, with neutrons weighted by a constant RBE of 10. PMID:18582156

  17. Internal dosimetry of tritium

    SciTech Connect

    LaBone, T.R.

    1992-01-01

    Tritium is an interesting radionuclide from the perspective of internal dosimetry because of the wide variety of chemical compounds in which it can appear, its unusual routes of entry into the body, and its ability to exchange with stable hydrogen in surrounding material. In this report the internal dosimetry of tritium compounds is reviewed, with emphasis on methods of evaluating bioassay data following chronic and acute intakes. The assumptions and models used in the derivation of Annual Limits on Intake (ALI) and Derived Air Concentrations (DAC) for tritium are also discussed.

  18. Internal dosimetry of tritium

    SciTech Connect

    LaBone, T.R.

    1992-06-01

    Tritium is an interesting radionuclide from the perspective of internal dosimetry because of the wide variety of chemical compounds in which it can appear, its unusual routes of entry into the body, and its ability to exchange with stable hydrogen in surrounding material. In this report the internal dosimetry of tritium compounds is reviewed, with emphasis on methods of evaluating bioassay data following chronic and acute intakes. The assumptions and models used in the derivation of Annual Limits on Intake (ALI) and Derived Air Concentrations (DAC) for tritium are also discussed.

  19. Dosimetry with diamond detectors

    NASA Astrophysics Data System (ADS)

    Gervino, G.; Marino, C.; Silvestri, F.; Lavagno, A.; Truc, F.

    2010-05-01

    In this paper we present the dosimetry analysis in terms of stability and repeatability of the signal and dose rate dependence of a synthetic single crystal diamond grown by Chemical Vapor Deposition (CVD) technique. The measurements carried out by 5 MeV X-ray photons beam show very promising results, even if the dose rate detector response points out that the charge trapping centers distribution is not uniform inside the crystal volume. This handicap that affects the detectors performances, must be ascribed to the growing process. Synthetic single crystal diamonds could be a valuable alternative to air ionization chambers for quality beam control and for intensity modulated radiation therapy beams dosimetry.

  20. 10 CFR 35.630 - Dosimetry equipment.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 1 2014-01-01 2014-01-01 false Dosimetry equipment. 35.630 Section 35.630 Energy NUCLEAR REGULATORY COMMISSION MEDICAL USE OF BYPRODUCT MATERIAL Photon Emitting Remote Afterloader Units, Teletherapy... system or source traceable to the National Institute of Standards and Technology (NIST) and...

  1. 10 CFR 35.630 - Dosimetry equipment.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 1 2011-01-01 2011-01-01 false Dosimetry equipment. 35.630 Section 35.630 Energy NUCLEAR REGULATORY COMMISSION MEDICAL USE OF BYPRODUCT MATERIAL Photon Emitting Remote Afterloader Units, Teletherapy... system or source traceable to the National Institute of Standards and Technology (NIST) and...

  2. 10 CFR 35.630 - Dosimetry equipment.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Dosimetry equipment. 35.630 Section 35.630 Energy NUCLEAR REGULATORY COMMISSION MEDICAL USE OF BYPRODUCT MATERIAL Photon Emitting Remote Afterloader Units, Teletherapy... system or source traceable to the National Institute of Standards and Technology (NIST) and...

  3. 10 CFR 35.630 - Dosimetry equipment.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 1 2013-01-01 2013-01-01 false Dosimetry equipment. 35.630 Section 35.630 Energy NUCLEAR REGULATORY COMMISSION MEDICAL USE OF BYPRODUCT MATERIAL Photon Emitting Remote Afterloader Units, Teletherapy... system or source traceable to the National Institute of Standards and Technology (NIST) and...

  4. The development of fetal dosimetry and its application to A-bomb survivors exposed in utero.

    PubMed

    Chen, Jing

    2012-03-01

    The cohort of the atomic bomb survivors of Hiroshima and Nagasaki comprises the major basis for investigations of health effects induced by ionising radiation in humans. To study the health effects associated with radiation exposure before birth, fetal dosimetry is needed if significant differences exist between the fetal absorbed dose and the mother's uterine dose. Combining total neutron and gamma ray free-in-air fluences at 1 m above ground with fluence-to-absorbed dose conversion coefficients, fetal doses were calculated for various exposure orientations at the ground distance of 1500 m from the hypocentres in Hiroshima and Nagasaki. The results showed that the mother's uterine dose can serve as a good surrogate for the dose of the embryo and fetus in the first trimester. However, significant differences exist between doses of the fetus of different ages. If the mother's uterine dose were used as a surrogate, doses to the fetus in the last two trimesters could be overestimated by more than 20 % for exposure orientations facing towards and away from the hypocentre while significantly underestimated for lateral positions relative to the hypocentre. In newer fetal models, the brain is modelled for all fetal ages. Brain doses to the 3-month fetus are generally higher than those to an embryo and fetus of other ages. In most cases, brain absorbed doses differ significantly from the doses to the entire fetal body. In order to accurately assess radiation effects to the fetal brain, it is necessary to determine brain doses separately. PMID:21816724

  5. Prevalence of monoclonal gammopathy of undetermined significance in Asia: a viewpoint from nagasaki atomic bomb survivors.

    PubMed

    Iwanaga, Masako; Tomonaga, Masao

    2014-02-01

    Exposure to ionizing radiation is a known environmental risk factor for a variety of cancers including hematological malignancies, such as leukemia, myelodysplastic syndromes, and multiple myeloma. Therefore, for Hiroshima and Nagasaki atomic bomb survivors (surviving victims who were exposed to ionizing radiation emitted from the nuclear weapons), several cancer-screening tests have been provided annually, with government support, to detect the early stage of malignancies. An M-protein screening test has been used to detect multiple myeloma at an early stage among atomic bomb survivors. In the screening process, a number of patients with monoclonal gammopathy of undetermined significance (MGUS), in addition to multiple myeloma, have been identified. In 2009 and 2011, we reported the age- and sex-specific prevalence of MGUS between 1988 and 2004 and the possible role of radiation exposure in the development of MGUS using the screening data of more than 1000 patients with MGUS among approximately 52,000 Nagasaki atomic bomb survivors. The findings included: (1) a significant lower overall prevalence (2.1%) than that observed in Caucasian or African-origin populations; (2) a significantly higher prevalence in men than in women; (3) an age-related increase in the prevalence; (4) a significantly higher prevalence in people exposed to higher radiation doses only among those exposed at age 20 years or younger; and (5) a lower frequency of immunoglobulin M MGUS in Japanese patients than in patients in Western countries. The large study of MGUS among Nagasaki atomic bomb survivors has provided important findings for the etiology of MGUS, including a possible role of radiation exposure on the cause of MGUS and an ethnicity-related difference in the characteristics of MGUS. PMID:24461807

  6. A mm-Scale Dosimetry System Based on Optically Stimulated Luminescence of Beryllium Oxide for Investigation of Dose Rate Profiles in Constricted Environments - 12219

    SciTech Connect

    Sommer, Marian; Jahn, Axel; Sommer, Dora; Henniger, Juergen; Praetorius, Reiner M.

    2012-07-01

    The dismantling of the former German fuel reprocessing research center Wiederaufbeitungsanlage Karlsruhe requires extensive investigations of contamination and dose rate inside of the shielded areas. Particularly for first the exploration of radiation field existing thermo-element pipes may offer access to the tanks and to other interesting points without the risk of contamination. Because of their small dimension, almost no active dosimetry systems are able to measure inside the pipes. New mm-scale luminescence dosimeters in combination with a packing and transport technique are presented. The dosimeters could measure doses from 0.1 mGy up to more than 100 Gy. Hence, over the possible exposure time durations, dose rates from μGyh{sup -1} up to 1000 Gyh{sup -1} are ascertainable. For potential users the system opens the opportunity for investigation of dose rates inside of shielding and in contaminated environments. Particularly in constricted environments the technique is a unique solution for dose and dose rate measurement tasks. Within the linear dose range up to several ten Gy, the uncertainty of the results is less than 5%. 100 Gy-doses can be specified within 20%, with individual high dose calibration of the detectors even better. For WAK and other potential users the system offers the opportunity to investigate dose rates inside of shieldings and in contaminated environments. Particularly in constricted environments the technique is an unique solution for dose and dose rate measurements. (authors)

  7. Numerical Analysis of Organ Doses Delivered During Computed Tomography Examinations Using Japanese Adult Phantoms with the WAZA-ARI Dosimetry System.

    PubMed

    Takahashi, Fumiaki; Sato, Kaoru; Endo, Akira; Ono, Koji; Ban, Nobuhiko; Hasegawa, Takayuki; Katsunuma, Yasushi; Yoshitake, Takayasu; Kai, Michiaki

    2015-08-01

    A dosimetry system for computed tomography (CT) examinations, named WAZA-ARI, is being developed to accurately assess radiation doses to patients in Japan. For dose calculations in WAZA-ARI, organ doses were numerically analyzed using average adult Japanese male (JM) and female (JF) phantoms with the Particle and Heavy Ion Transport code System (PHITS). Experimental studies clarified the photon energy distribution of emitted photons and dose profiles on the table for some multi-detector row CT (MDCT) devices. Numerical analyses using a source model in PHITS could specifically take into account emissions of x rays from the tube to the table with attenuation of photons through a beam-shaping filter for each MDCT device based on the experiment results. The source model was validated by measuring the CT dose index (CTDI). Numerical analyses with PHITS revealed a concordance of organ doses with body sizes of the JM and JF phantoms. The organ doses in the JM phantoms were compared with data obtained using previously developed systems. In addition, the dose calculations in WAZA-ARI were verified with previously reported results by realistic NUBAS phantoms and radiation dose measurement using a physical Japanese model (THRA1 phantom). The results imply that numerical analyses using the Japanese phantoms and specified source models can give reasonable estimates of dose for MDCT devices for typical Japanese adults. PMID:26107430

  8. Recommended improvements to the DS02 dosimetry system's calculation of organ doses and their potential advantages for the Radiation Effects Research Foundation.

    PubMed

    Cullings, Harry M

    2012-03-01

    The Radiation Effects Research Foundation (RERF) uses a dosimetry system to calculate radiation doses received by the Japanese atomic bomb survivors based on their reported location and shielding at the time of exposure. The current system, DS02, completed in 2003, calculates detailed doses to 15 particular organs of the body from neutrons and gamma rays, using new source terms and transport calculations as well as some other improvements in the calculation of terrain and structural shielding, but continues to use methods from an older system, DS86, to account for body self-shielding. Although recent developments in models of the human body from medical imaging, along with contemporary computer speed and software, allow for improvement of the calculated organ doses, before undertaking changes to the organ dose calculations, it is important to evaluate the improvements that can be made and their potential contribution to RERF's research. The analysis provided here suggests that the most important improvements can be made by providing calculations for more organs or tissues and by providing a larger series of age- and sex-specific models of the human body from birth to adulthood, as well as fetal models. PMID:22262817

  9. SU-E-CAMPUS-T-05: Preliminary Results On a 2D Dosimetry System Based On the Optically Stimulated Luminescence of Al2O3

    SciTech Connect

    Ahmed, M; Eller, S; Yukihara, E; Schnell, E; Ahmad, S; Akselrod, M; Hanson, O

    2014-06-15

    Purpose: To develop a precise 2D dose mapping technique based on the optically stimulated luminescence (OSL) from Al{sub 2}O{sub 3} films for medical applications. Methods: A 2D laser scanning reader was developed using fast F{sup +}-center (lifetime of <7 ns) and slow F-center (lifetime of 35 ms) OSL emission from newly developed Al{sub 2}O{sub 3} films (Landauer Inc.). An algorithm was developed to correct images for both material and system properties. Since greater contribution of the F??-center emission in the recorded signal increases the readout efficiency and robustness of image corrections, Al{sub 2}O{sub 3}:C,Mg film samples are being investigated in addition to Al{sub 2}O{sub 3}:C samples. Preliminary investigations include exposure of the films to a 6 MV photon beam at 10 cm depth in solid water phantom with an SSD of 100 cm, using a 10 cm × 10 cm flat field or a 4 cm × 4 cm field with a 60° wedge filter. Kodak EDR2 radiographic film and EBT2 Gafchromic film were also exposed for comparison. Results: The results indicate that the algorithm is able to correct images and calculate 2D dose. For the wedge field irradiation, the calculated dose at the center of the field was 0.9 Gy for Al{sub 2}O{sub 3}:C and 0.87 Gy for Al{sub 2}O{sub 3}:C,Mg, whereas, the delivered dose was 0.95 Gy. A good qualitative agreement of the dose profiles was obtained between the OSL films and EDR2 and EBT2 films. Laboratory tests using a beta source suggest that a large dynamic range (10{sup −2}−10{sup 2} Gy) can be achieved using this technique. Conclusion: A 2D dosimetry system and an in-house image correction algorithm were developed for 2D film dosimetry in medical applications. The system is in the preliminary stage of development, but the data demonstrates the feasibility of this approach. This work was supported by Landauer, Inc.

  10. Ion-kill dosimetry

    NASA Technical Reports Server (NTRS)

    Katz, R.; Cucinotta, F. A.; Fromm, M.; Chambaudet, A.

    2001-01-01

    Unanticipated late effects in neutron and heavy ion therapy, not attributable to overdose, imply a qualitative difference between low and high LET therapy. We identify that difference as 'ion kill', associated with the spectrum of z/beta in the radiation field, whose measurement we label 'ion-kill dosimetry'.

  11. In-Vessel and Ex-Vessel Neutron Dosimetry Programs in Korea

    NASA Astrophysics Data System (ADS)

    Yoo, Choon Sung; Kim, Byoung Chul; Fero, Arnold H.; Anderson, Stanwood L.

    2016-02-01

    In Korea, 20 PWRs are operating and 4 more PWRs are under construction. The in-vessel neutron dosimetry programs have been designed and implemented since each plant began operation. In addition to the in-vessel dosimetry program, ex-vessel neutron dosimetry systems have been installed for 16 PWRs. The objective of this paper is to describe the in-vessel and ex-vessel neutron dosimetry program of the PWRs in Korea and to compare in-vessel and ex-vessel dosimetry evaluation results. For this purpose plant and cycle specific forward neutron transport calculations and dosimetry measurement evaluations were carried out according to Regulatory Guide 1.190. Comparisons between the calculations and measurements were also performed for the reaction rates of each dosimetry sensor and the results show good agreement.

  12. Reactor Dosimetry State of the Art 2008

    NASA Astrophysics Data System (ADS)

    Voorbraak, Wim; Debarberis, Luigi; D'Hondt, Pierre; Wagemans, Jan

    2009-08-01

    from the first-generation nuclear-powered submarines by gamma scanning / A. F. Usatyi. L. A. Serdyukova and B. S. Stepennov -- Oral session 3: Power plant surveillance. Upgraded neutron dosimetry procedure for VVER-440 surveillance specimens / V. Kochkin ... [et al.]. Neutron dosimetry on the full-core first generation VVER-440 aimed to reactor support structure load evaluation / P. Borodkin ... [et al.]. Ex-vessel neutron dosimetry programs for PWRs in Korea / C. S. Yoo. B. C. Kim and C. C. Kim. Comparison of irradiation conditions of VVER-1000 reactor pressure vessel and surveillance specimens for various core loadings / V. N. Bukanov ... [et al.]. Re-evaluation of dosimetry in the new surveillance program for the Loviisa 1 VVER-440 reactor / T. Serén -- Oral session 4: Benchmarks, intercomparisons and adjustment methods. Determination of the neutron parameter's uncertainties using the stochastic methods of uncertainty propagation and analysis / G. Grégoire ... [et al.].Covariance matrices for calculated neutron spectra and measured dosimeter responses / J. G. Williams ... [et al.]. The role of dosimetry at the high flux reactor / S. C. van der Marek ... [et al.]. Calibration of a manganese bath relative to Cf-252 nu-bar / D. M. Gilliam, A. T. Yue and M. Scott Dewey. Major upgrade of the reactor dosimetry interpretation methodology used at the CEA: general principle / C. Destouches ... [et al.] -- Oral session 5: power plant surveillance. The role of ex-vessel neutron dosimetry in reactor vessel surveillance in South Korea / B.-C. Kim ... [et al.]. Spanish RPV surveillance programmes: lessons learned and current activities / A. Ballesteros and X. Jardí. Atucha I nuclear power plant extended dosimetry and assessment / H. Blaumann ... [et al.]. Monitoring of radiation load of pressure vessels of Russian VVER in compliance with license amendments / G. Borodkin ... [et al.] -- Poster session 2: Test reactors, accelerators and advanced systems; cross sections, nuclear

  13. EPR dosimetry teeth in past and future accidents: A prospective look at a retrospective method

    SciTech Connect

    Haskell, E.; Kenner, G.; Hayes, R.; Chumak, V.; Shalom, S.

    1997-03-01

    Accurate assessments of doses received by individuals exposed to radiation from nuclear accidents and incidents such as those at Hiroshima and Nagasaki, the Nevada test site, Cheliabinsk and Mayak are required for epidemiological studies seeking to establish relationships between radiation dose and health effects. One method of retrospective dosimetry which allows for measurement of cumulative gamma ray doses received by exposed individuals is electron paramagnetic resonance spectroscopy (EPR) of tooth enamel. Tooth enamel stores and retains, indefinitely, information on absorbed radiation dose. And teeth are available in every population as a result of dental extraction for medical reasons including periodontal disease and impacted wisdom teeth. In the case of children, deciduous teeth, which are shed between the ages of 7 and 13, can be a very important dosimetric source if documented collection is implemented shortly following an accident.

  14. ESR Dosimetry for Atomic Bomb Survivors Using Shell Buttons and Tooth Enamel

    NASA Astrophysics Data System (ADS)

    Ikeya, Motoji; Miyajima, Junko; Okajima, Shunzo

    1984-09-01

    Atomic bomb radiation doses to humans at Nagasaki and Hiroshima are investigated by electron spin resonance (ESR) from shell buttons and tooth enamel voluntarily supplied by survivors. A shell button gives a dose of 2.1± 0.2 Gy with ESR signals at g=2.001 and g=1.997 while the signal at g=1.997 for the tooth enamel of the same person is 1.9± 0.5 Gy. Other teeth show doses from about 0.5 Gy to 3 Gy. An apparent shielding converted to a concrete thickness is given using the T65D calculated in 1965. Teeth extracted during dental treatment should be preserved for cumulative radiation dosimetry.

  15. Investigation of radiation effects in Hiroshima and Nagasaki using a general Monte Carlo-discrete ordinates coupling scheme

    SciTech Connect

    Cramer, S.N.; Slater, C.O.

    1990-05-01

    A general Monte Carlo-discrete ordinates radiation transport coupling procedure has been created to study effects of the radiation environment in Hiroshima and Nagasaki due to the bombing of these two cities. The forward two-dimensional free-field air-over-ground flux is coupled with an adjoint Monte Carlo calculation. The size, orientation, or translation of the Monte Carlo geometry is unrestricted. The radiation effects calculated are the dose in the interior of a large concrete building in Nagasaki and the activation production of Co-60 and P-32 in Hiroshima. 20 refs., 6 figs., 1 tab.

  16. Investigation of radiation effects in Hiroshima and Nagasaki using a general Monte Carlo-discrete ordinates coupling scheme

    SciTech Connect

    Cramer, S.N.; Slater, C.O. )

    1993-05-01

    A general Monte Carlo-discrete ordinates radiation transport coupling procedure has been created to study effects of the radiation environment in Hiroshima and Nagasaki due to the bombing of these two cities. The forward two-dimensional, free-field, air-over-ground flux is coupled with an adjoint Monte Carlo calculation. The size, orientation, or translation of the Monte Carlo geometry is unrestricted. The radiation effects calculated are the dose in the interior of a large concrete building in Nagasaki and the activation production of [sup 60]Co and [sup 32]P in Hiroshima.

  17. SU-D-213-05: Design, Evaluation and First Applications of a Off-Site State-Of-The-Art 3D Dosimetry System

    SciTech Connect

    Malcolm, J; Mein, S; McNiven, A; Letourneau, D; Oldham, M

    2015-06-15

    Purpose: To design, construct and commission a prototype in-house three dimensional (3D) dose verification system for stereotatic body radiotherapy (SBRT) verification at an off-site partner institution. To investigate the potential of this system to achieve sufficient performance (1mm resolution, 3% noise, within 3% of true dose reading) for SBRT verification. Methods: The system was designed utilizing a parallel ray geometry instigated by precision telecentric lenses and an LED 630nm light source. Using a radiochromic dosimeter, a 3D dosimetric comparison with our gold-standard system and treatment planning software (Eclipse) was done for a four-field box treatment, under gamma passing criteria of 3%/3mm/10% dose threshold. Post off-site installation, deviations in the system’s dose readout performance was assessed by rescanning the four-field box irradiated dosimeter and using line-profiles to compare on-site and off-site mean and noise levels in four distinct dose regions. As a final step, an end-to-end test of the system was completed at the off-site location, including CT-simulation, irradiation of the dosimeter and a 3D dosimetric comparison of the planned (Pinnacle{sup 3}) to delivered dose for a spinal SBRT treatment(12 Gy per fraction). Results: The noise level in the high and medium dose regions of the four field box treatment was relatively 5% pre and post installation. This reflects the reduction in positional uncertainty through the new design. This At 1mm dose voxels, the gamma pass rates(3%,3mm) for our in-house gold standard system and the off-site system were comparable at 95.8% and 93.2% respectively. Conclusion: This work will describe the end-to-end process and results of designing, installing, and commissioning a state-of-the-art 3D dosimetry system created for verification of advanced radiation treatments including spinal radiosurgery.

  18. Evaluation and optimization of the new EBT2 radiochromic film dosimetry system for patient dose verification in radiotherapy

    NASA Astrophysics Data System (ADS)

    Richley, L.; John, A. C.; Coomber, H.; Fletcher, S.

    2010-05-01

    A new radiochromic film, the yellow Gafchromic EBT2, has been marketed as a drop-in replacement for the discontinued blue EBT film. In order to verify the manufacturer's claims prior to clinical use, EBT2 was characterized in transmission, and the less commonly used, reflection modes with an Epson Expression 10000XL A3 flatbed scanner. The red channel was confirmed to provide the greatest sensitivity and was used for all measurements. The post-irradiation darkening of the film was investigated, and the relative response was found to be dose dependent with higher doses stabilizing earlier than lower doses. After 13 h all dose levels had stabilized to within 1% of their value at 24 h. Uniformity of irradiated EBT2 films was within 0.8% and 1.2% (2SD of signal), in reflection and transmission modes, respectively. The light scattering effect, arising from the structure and thickness of EBT2, was found to give rise to an apparent scanner non-uniformity of up to 5.5% in signal. In reflection mode, differences of up to 1.2% were found between the signal obtained from a small film fragment (5 × 5 cm2) and the signal obtained from the same fragment bordered by extra film. Further work is needed to determine the origin of this effect, as there will be implications for reflection dosimetry of intensity modulated fields; reflection mode cannot yet be regarded as a viable alternative to transmission mode. Our results suggest that EBT2 film is a valid alternative, rather than a direct replacement for EBT film.

  19. Hanford External Dosimetry Technical Basis Manual PNL-MA-842

    SciTech Connect

    Rathbone, Bruce A.

    2009-08-28

    The Hanford External Dosimetry Technical Basis Manual PNL-MA-842 documents the design and implementation of the external dosimetry system used at Hanford. The manual describes the dosimeter design, processing protocols, dose calculation methodology, radiation fields encountered, dosimeter response characteristics, limitations of dosimeter design under field conditions, and makes recommendations for effective use of the dosimeters in the field. The manual describes the technical basis for the dosimetry system in a manner intended to help ensure defensibility of the dose of record at Hanford and to demonstrate compliance with 10 CFR 835, DOELAP, DOE-RL, ORP, PNSO, and Hanford contractor requirements. The dosimetry system is operated by PNNL’s Hanford External Dosimetry Program (HEDP) which provides dosimetry services to all Hanford contractors. The primary users of this manual are DOE and DOE contractors at Hanford using the dosimetry services of PNNL. Development and maintenance of this manual is funded directly by DOE and DOE contractors. Its contents have been reviewed and approved by DOE and DOE contractors at Hanford through the Hanford Personnel Dosimetry Advisory Committee (HPDAC) which is chartered and chaired by DOE-RL and serves as means of coordinating dosimetry practices across contractors at Hanford. This manual was established in 1996. Since inception, it has been revised many times and maintained by PNNL as a controlled document with controlled distribution. The first revision to be released through PNNL’s Electronic Records & Information Capture Architecture (ERICA) database was designated Revision 0. Revision numbers that are whole numbers reflect major revisions typically involving changes to all chapters in the document. Revision numbers that include a decimal fraction reflect minor revisions, usually restricted to selected chapters or selected pages in the document.

  20. 4D dosimetry and its applications to pre-treatment quality control and real-time in vivo dosimetry of VMAT treatments

    NASA Astrophysics Data System (ADS)

    Nordström, F.; Wetterstedt, S. af; Bäck, S. Å. J.

    2013-06-01

    In this study, a 4D dosimetry concept was developed. This concept included a method for calculation of 3D reference absorbed dose matrices at every control point of the delivery using a clinical treatment planning system (TPS). Further, the gamma evaluation method was extended to incorporate the 4th dimension of the TPS calculated dose distributions. The applications of the 4D dosimetry concept on pre-treatment quality control and real-time in vivo dosimetry were investigated.

  1. Multilocus sequence typing of Cryptococcus neoformans in non-HIV associated cryptococcosis in Nagasaki, Japan.

    PubMed

    Mihara, Tomo; Izumikawa, Koichi; Kakeya, Hiroshi; Ngamskulrungroj, Popchai; Umeyama, Takashi; Takazono, Takahiro; Tashiro, Masato; Nakamura, Shigeki; Imamura, Yoshifumi; Miyazaki, Taiga; Ohno, Hideaki; Yamamoto, Yoshihiro; Yanagihara, Katsunori; Miyzaki, Yoshitsugu; Kohno, Shigeru

    2013-04-01

    Cryptococcosis is primarily caused by two Cryptococcus species, i.e., Cryptococcus neoformans and C. gattii. Both include several genetically diverse subgroups that can be differentiated using various molecular strain typing methods. Since little is known about the molecular epidemiology of the C. neoformans/C. gattii species complex in Japan, we conducted a molecular epidemiological analysis of 35 C. neoformans isolates from non-HIV patients in Nagasaki, Japan and 10 environmental isolates from Thailand. All were analyzed using URA5-restriction fragment length polymorphism (RFLP) and multilocus sequence typing (MLST). Combined sequence data for all isolates were evaluated with the neighbor-joining method. All were found to be serotype A and mating type MATα. Thirty-two of the 35 clinical isolates molecular type VNI, while the three remaining isolates were VNII as determined through the URA5-RFLP method. Thirty-one of the VNI isolates were identified as MLST sequence type (ST) 5, the remaining one was ST 32 and the three VNII isolates were found to be ST 43. All the environmental isolates were identified as molecular type VNI (four MLST ST 5 and six ST 4). Our study shows that C. neoformans isolates in Nagasaki are genetically homogeneous, with most of the isolates being ST 5. PMID:22901045

  2. Effects of Meteorological Conditions on PM2.5 Concentrations in Nagasaki, Japan

    PubMed Central

    Wang, Jianhua; Ogawa, Susumu

    2015-01-01

    The fine particulate matter (PM2.5) problem has attracted much scientific and public attention, due to its effects on visibility, human health, and global climate. There are three factors that have important effect on PM2.5 mass concentration: domestic pollutant emission sources, external sources outside of the country, and the meteorological conditions. Nagasaki is a coastal prefecture located at the westernmost part of Japan, which is an ideal location to study pollutants from long range transport and correlation between PM2.5 and meteorological conditions. In this paper, PM2.5 concentration data and meteorological data were obtained during 1 January 2013~31 December 2013. The spatial distribution depicts that the western part of the study area has the most serious PM2.5 pollution. The correlation analysis results between PM2.5 concentration and meteorological data showed that temperature had a negative, and precipitation had a positive, correlation with PM2.5. There was a threshold in the correlations between humidity and wind speed and PM2.5. The correlation was positive or negative depending on the meteorological variable values, if these were lower or higher than the threshold. From the relationship with wind direction, it can be depicted that the west wind might bring the most pollutants to Nagasaki. PMID:26247953

  3. Effects of radiation on the incidence of prostate cancer among Nagasaki atomic bomb survivors.

    PubMed

    Kondo, Hisayoshi; Soda, Midori; Mine, Mariko; Yokota, Kenichi

    2013-10-01

    Atomic bomb survivors have been reported to have an increased risk of some cancers, especially leukemia. However, the risk of prostate cancer in atomic bomb survivors is not known to have been examined previously. This study examined the association between atomic bomb radiation and the incidence of prostate cancer among male Nagasaki atomic bomb survivors. The subjects were classified by distance from the hypocenter into a proximal group (<2 km), a distal group (≥2 km), and an early entrance group (those who entered the region <2 km from the hypocenter within 2 weeks after the explosion). Between 1996 and 2009, 631 new cases of prostate cancer were identified among approximately 18 400 male Nagasaki atomic bomb survivors who were alive in 1996. The Cox proportional hazard model was used to estimate the risk of prostate cancer development, with adjustment for age at atomic bomb explosion, attained age, smoking status, and alcohol consumption. Compared with the distal group, the proximal group had significant increased risks of total, localized, and high-grade prostate cancer (relative risk and 95% confidence interval: 1.51 [1.21-1.89]; 1.80 [1.26-2.57]; and 1.88 [1.20-2.94], respectively). This report is the first known to reveal a significant relationship between atomic bomb radiation and prostate cancer. PMID:23859763

  4. Personnel neutron dosimetry using electrochemically etched CR-39 foils

    SciTech Connect

    Hankins, D.E.; Homann, S.; Westermark, J.

    1986-09-17

    A personnel neutron dosimetry system has been developed based on the electrochemical etching of CR-39 plastic at elevated temperatures. The doses obtained using this dosimeter system are more accurate than those obtained using other dosimetry systems, especially when varied neutron spectra are encountered. This Cr-39 dosimetry system does not have the severe energy dependence that exists with albedo neutron dosimeters or the fading and reading problems encountered with NTA film. The dosimetry system employs an electrochemical etch procedure that be used to process large numbers of Cr-39 dosimeters. The etch procedure is suitable for operations where the number of personnel requires that many CR-39 dosimeters be processed. Experience shows that one full-time technician can etch and evaluate 2000 foils per month. The energy response to neutrons is fairly flat from about 80 keV to 3.5 MeV, but drops by about a factor of three in the 13 to 16 MeV range. The sensitivity of the dosimetry system is about 7 tracks/cm/sup 2//mrem, with a background equivalent to about 8 mrem for new CR-39 foils. The limit of sensitivity is approximately 10 mrem. The dosimeter has a significant variation in directional dependence, dropping to about 20% at 90/sup 0/. This dosimeter has been used for personnel neutron dosimetry at the Lawrence Livermore National Laboratory for more tha 18 months. 6 refs., 23 figs., 2 tabs.

  5. Comparison of 3D dose distributions for HDR {sup 192}Ir brachytherapy sources with normoxic polymer gel dosimetry and treatment planning system

    SciTech Connect

    Senkesen, Oznur; Tezcanli, Evrim; Buyuksarac, Bora; Ozbay, Ismail

    2014-10-01

    Radiation fluence changes caused by the dosimeter itself and poor spatial resolution may lead to lack of 3-dimensional (3D) information depending on the features of the dosimeter and quality assurance of dose distributions for high–dose rate (HDR) iridium-192 ({sup 192}Ir) brachytherapy sources is challenging and experimental dosimetry methods used for brachytherapy sources are limited. In this study, we investigated 3D dose distributions of {sup 192}Ir brachytherapy sources for irradiation with single and multiple dwell positions using a normoxic gel dosimeter and compared them with treatment planning system (TPS) calculations. For dose calibration purposes, 100-mL gel-containing vials were irradiated at predefined doses and then scanned in an magnetic resonance (MR) imaging unit. Gel phantoms prepared in 2 spherical glasses were irradiated with {sup 192}Ir for the calculated dwell positions, and MR scans of the phantoms were obtained. The images were analyzed with MATLAB software. Dose distributions and profiles derived with 1-mm resolution were compared with TPS calculations. Linearity was observed between the delivered dose and the reciprocal of the T2 relaxation time constant of the gel. The x-, y-, and z-axes were defined as the sagittal, coronal, and axial planes, respectively, the sagittal and axial planes were defined parallel to the long axis of the source while the coronal plane was defined horizontally to the long axis of the source. The differences between measured and calculated profile widths of 3-cm source length and point source for 70%, 50%, and 30% isodose lines were evaluated at 3 dose levels using 18 profiles of comparison. The calculations for 3-cm source length revealed a difference of > 3 mm in 1 coordinate at 50% profile width on the sagittal plane and 3 coordinates at 70% profile width and 2 coordinates at 50% and 30% profile widths on the axial plane. Calculations on the coronal plane for 3-cm source length showed > 3-mm difference in 1

  6. Comparison of 3D dose distributions for HDR 192Ir brachytherapy sources with normoxic polymer gel dosimetry and treatment planning system.

    PubMed

    Senkesen, Oznur; Tezcanli, Evrim; Buyuksarac, Bora; Ozbay, Ismail

    2014-01-01

    Radiation fluence changes caused by the dosimeter itself and poor spatial resolution may lead to lack of 3-dimensional (3D) information depending on the features of the dosimeter and quality assurance of dose distributions for high-dose rate (HDR) iridium-192 ((192)Ir) brachytherapy sources is challenging and experimental dosimetry methods used for brachytherapy sources are limited. In this study, we investigated 3D dose distributions of (192)Ir brachytherapy sources for irradiation with single and multiple dwell positions using a normoxic gel dosimeter and compared them with treatment planning system (TPS) calculations. For dose calibration purposes, 100-mL gel-containing vials were irradiated at predefined doses and then scanned in an magnetic resonance (MR) imaging unit. Gel phantoms prepared in 2 spherical glasses were irradiated with (192)Ir for the calculated dwell positions, and MR scans of the phantoms were obtained. The images were analyzed with MATLAB software. Dose distributions and profiles derived with 1-mm resolution were compared with TPS calculations. Linearity was observed between the delivered dose and the reciprocal of the T2 relaxation time constant of the gel. The x-, y-, and z-axes were defined as the sagittal, coronal, and axial planes, respectively, the sagittal and axial planes were defined parallel to the long axis of the source while the coronal plane was defined horizontally to the long axis of the source. The differences between measured and calculated profile widths of 3-cm source length and point source for 70%, 50%, and 30% isodose lines were evaluated at 3 dose levels using 18 profiles of comparison. The calculations for 3-cm source length revealed a difference of > 3mm in 1 coordinate at 50% profile width on the sagittal plane and 3 coordinates at 70% profile width and 2 coordinates at 50% and 30% profile widths on the axial plane. Calculations on the coronal plane for 3-cm source length showed > 3-mm difference in 1 coordinate at

  7. TG-69: radiographic film for megavoltage beam dosimetry.

    PubMed

    Pai, Sujatha; Das, Indra J; Dempsey, James F; Lam, Kwok L; Losasso, Thomas J; Olch, Arthur J; Palta, Jatinder R; Reinstein, Lawrence E; Ritt, Dan; Wilcox, Ellen E

    2007-06-01

    TG-69 is a task group report of the AAPM on the use of radiographic film for dosimetry. Radiographic films have been used for radiation dosimetry since the discovery of x-rays and have become an integral part of dose verification for both routine quality assurance and for complex treatments such as soft wedges (dynamic and virtual), intensity modulated radiation therapy (IMRT), image guided radiation therapy (IGRT), and small field dosimetry like stereotactic radiosurgery. Film is convenient to use, spatially accurate, and provides a permanent record of the integrated two dimensional dose distributions. However, there are several challenges to obtaining high quality dosimetric results with film, namely, the dependence of optical density on photon energy, field size, depth, film batch sensitivity differences, film orientation, processing conditions, and scanner performance. Prior to the clinical implementation of a film dosimetry program, the film, processor, and scanner need to be tested to characterize them with respect to these variables. Also, the physicist must understand the basic characteristics of all components of film dosimetry systems. The primary mission of this task group report is to provide guidelines for film selection, irradiation, processing, scanning, and interpretation to allow the physicist to accurately and precisely measure dose with film. Additionally, we present the basic principles and characteristics of film, processors, and scanners. Procedural recommendations are made for each of the steps required for film dosimetry and guidance is given regarding expected levels of accuracy. Finally, some clinical applications of film dosimetry are discussed. PMID:17654924

  8. PREFACE: Third International Conference on Radiotherapy Gel Dosimetry

    NASA Astrophysics Data System (ADS)

    DeDeene, Yves; Baldock, Clive

    2004-01-01

    Gel dosimetry is not merely another dosimetry technique. Gel dosimeters are integrating dosimeters that enable dose verification in three dimensions. The application of a 3D dosimetry technique in the clinic would give a real push to the implementation of advanced high-precision radiotherapy technologies in many institutes. It can be expected that with the recent developments in the field towards more user-friendly gel systems and imaging modalities, gel dosimetry will become a vital link in the chain of high-precision radiation cancer therapy in the near future. Many researchers all over the world have contributed to the emerging technology of gel dosimetry. The research field of gel dosimetry is recognized to be very broad from polymer and analytical chemistry and material research to imaging technologies. The DOSGEL conferences in the past have proven to be an important forum at which material scientists, chemists, medical physicists, magnetic resonance imaging and radiation specialists brought together a critical mass of thoughts, findings and considerations. DOSGEL 2004 has been endorsed by many international, supra-national and national medical physics organizations and publishers. These proceedings contain 51 papers that cover various aspects of gel dosimetry.

  9. Experimental validation of a versatile system of CT dosimetry using a conventional ion chamber: Beyond CTDI{sub 100}

    SciTech Connect

    Dixon, Robert L.; Ballard, Adam C.

    2007-08-15

    This article is an experimental demonstration and authentication of a new method of computed tomography dosimetry [R. L. Dixon, Med. Phys. 30, 1272-1280 (2003)], which utilizes a short, conventional ion chamber rather than a pencil chamber, and which is more versatile than the latter. The value of CTDI{sub 100} correctly predicts the accumulated dose only for a total scan length L equal to 100 mm and underestimates the limiting equilibrium dose approached for longer, clinically relevant body scan lengths [R. L. Dixon, Med. Phys. 30, 1272-1280 (2003); K. D. Nakonechny, B. G. Fallone, and S. Rathee, Med. Phys. 32, 98-109 (2005); S. Mori, M. Endo, K. Nishizawa, T. Tsunoo, T. Aoyama, H. Fujiwara, and K. Murase, Med. Phys. 32, 1061-1069 (2005); R. L. Dixon, M. T. Munley, and E. Bayram, Med. Phys. 32, 3712-3728 (2005); R. L. Dixon, Med. Phys. 33, 3973-3976 (2006)]. Dixon [Med. Phys. 30, 1272-1280 (2003)] originally proposed an alternative using a short ion chamber and a helical scan acquisition to collect the same integral for any scan length L (and not limited 100 mm). The primary purpose of this work is to demonstrate experimentally the implementation, robustness, and versatility of this small ion chamber method in measuring the accumulated dose in the body phantom for any desired scan length L (up to the available phantom length) including the limiting equilibrium dose (symbolically CTDI{sub {infinity}}), and validation of the method against the pencil chamber methodology. Additionally, a simple and robust method for independently verifying the active length of a pencil chamber is described. The results of measurements made in a 400 mm long, 32 cm diameter polymethylmethacrylate body phantom using a small Farmer-type ion chamber and two pencil chambers of lengths l=100 and 150 mm confirm that the two methodologies provide the same dose values at the corresponding scan lengths L=l. The measured equilibrium doses obtained for GE MDCT scanners at 120 kVp are CTDI

  10. Experimental validation of a versatile system of CT dosimetry using a conventional ion chamber: beyond CTDI100.

    PubMed

    Dixon, Robert L; Ballard, Adam C

    2007-08-01

    This article is an experimental demonstration and authentication of a new method of computed tomography dosimetry [R. L. Dixon, Med. Phys. 30, 1272-1280 (2003)], which utilizes a short, conventional ion chamber rather than a pencil chamber, and which is more versatile than the latter. The value of CTDI100 correctly predicts the accumulated dose only for a total scan length L equal to 100 mm and underestimates the limiting equilibrium dose approached for longer, clinically relevant body scan lengths [R. L. Dixon, Med. Phys. 30, 1272-1280 (2003); K. D. Nakonechny, B. G. Fallone, and S. Rathee, Med. Phys. 32, 98-109 (2005); S. Mori, M. Endo, K. Nishizawa, T. Tsunoo, T. Aoyama, H. Fujiwara, and K. Murase, Med. Phys. 32, 1061-1069 (2005); R. L. Dixon, M. T. Munley, and E. Bayram, Med. Phys. 32, 3712-3728 (2005); R. L. Dixon, Med. Phys. 33, 3973-3976 (2006)]. Dixon [Med. Phys. 30, 1272-1280 (2003)] originally proposed an alternative using a short ion chamber and a helical scan acquisition to collect the same integral for any scan length L (and not limited 100 mm). The primary purpose of this work is to demonstrate experimentally the implementation, robustness, and versatility of this small ion chamber method in measuring the accumulated dose in the body phantom for any desired scan length L (up to the available phantom length) including the limiting equilibrium dose (symbolically CTDIinfinity), and validation of the method against the pencil chamber methodology. Additionally, a simple and robust method for independently verifying the active length of a pencil chamber is described. The results of measurements made in a 400 mm long, 32 cm diameter polymethylmethacrylate body phantom using a small Farmer-type ion chamber and two pencil chambers of lengths l=100 and 150 mm confirm that the two methodologies provide the same dose values at the corresponding scan lengths L=l. The measured equilibrium doses obtained for GE MDCT scanners at 120 kVp are CTDIinfinity = 1.75 CTDI

  11. In vivo dosimetry for IMRT

    SciTech Connect

    Vial, Philip

    2011-05-05

    In vivo dosimetry has a well established role in the quality assurance of 2D radiotherapy and 3D conformal radiotherapy. The role of in vivo dosimetry for IMRT is not as well established. IMRT introduces a range of technical issues that complicate in vivo dosimetry. The first decade or so of IMRT implementation has largely relied upon pre-treatment phantom based dose verification. During that time, several new devices and techniques for in vivo dosimetry have emerged with the promise of providing the ultimate form of IMRT dose verification. Solid state dosimeters continue to dominate the field of in vivo dosimetry in the IMRT era. In this report we review the literature on in vivo dosimetry for IMRT, with an emphasis on clinical evidence for different detector types. We describe the pros and cons of different detectors and techniques in the IMRT setting and the roles that they are likely to play in the future.

  12. Software for 3D radiotherapy dosimetry. Validation

    NASA Astrophysics Data System (ADS)

    Kozicki, Marek; Maras, Piotr; Karwowski, Andrzej C.

    2014-08-01

    The subject of this work is polyGeVero® software (GeVero Co., Poland), which has been developed to fill the requirements of fast calculations of 3D dosimetry data with the emphasis on polymer gel dosimetry for radiotherapy. This software comprises four workspaces that have been prepared for: (i) calculating calibration curves and calibration equations, (ii) storing the calibration characteristics of the 3D dosimeters, (iii) calculating 3D dose distributions in irradiated 3D dosimeters, and (iv) comparing 3D dose distributions obtained from measurements with the aid of 3D dosimeters and calculated with the aid of treatment planning systems (TPSs). The main features and functions of the software are described in this work. Moreover, the core algorithms were validated and the results are presented. The validation was performed using the data of the new PABIGnx polymer gel dosimeter. The polyGeVero® software simplifies and greatly accelerates the calculations of raw 3D dosimetry data. It is an effective tool for fast verification of TPS-generated plans for tumor irradiation when combined with a 3D dosimeter. Consequently, the software may facilitate calculations by the 3D dosimetry community. In this work, the calibration characteristics of the PABIGnx obtained through four calibration methods: multi vial, cross beam, depth dose, and brachytherapy, are discussed as well.

  13. Electron Paramagnetic Resonance Retrospective Dosimetry

    SciTech Connect

    Romanyukha, Alex; Trompier, Francois

    2011-05-05

    Necessity for, principles of, and general concepts of the electron paramagnetic resonance (EPR) retrospective dosimetry are presented. Also presented and given in details are examples of EPR retrospective dosimetry applications in tooth enamel, bone, and fingernails with focus on general approaches for solving technical and methodological problems. Advantages, drawbacks, and possible future developments are discussed and an extensive bibliography on EPR retrospective dosimetry is provided.

  14. Prostate PDT dosimetry

    PubMed Central

    Zhu, Timothy C.; Finlay, Jarod C.

    2015-01-01

    Summary We provide a review of the current state of dosimetry in prostate photodynamic therapy (PDT). PDT of the human prostate has been performed with a number of different photosensitizers and with a variety of dosimetry schemes. The simplest clinical light dose prescription is to quantify the total light energy emitted per length (J/cm) of cylindrical diffusing fibers (CDF) for patients treated with a defined photosensitizer injection per body weight. However, this approach does not take into account the light scattering by tissue and usually underestimates the local light fluence rate, and consequently the fluence. Techniques have been developed to characterize tissue optical properties and light fluence rates in vivo using interstitial measurements during prostate PDT. Optical methods have been developed to characterize tissue absorption and scattering spectra, which in turn provide information about tissue oxygenation and drug concentration. Fluorescence techniques can be used to quantify drug concentrations and photobleaching rates of photosensitizers. PMID:25046988

  15. Neutron beam measurement dosimetry

    SciTech Connect

    Amaro, C.R.

    1995-11-01

    This report describes animal dosimetry studies and phantom measurements. During 1994, 12 dogs were irradiated at BMRR as part of a 4 fraction dose tolerance study. The animals were first infused with BSH and irradiated daily for 4 consecutive days. BNL irradiated 2 beagles as part of their dose tolerance study using BPA fructose. In addition, a dog at WSU was irradiated at BMRR after an infusion of BPA fructose. During 1994, the INEL BNCT dosimetry team measured neutron flux and gamma dose profiles in two phantoms exposed to the epithermal neutron beam at the BMRR. These measurements were performed as a preparatory step to the commencement of human clinical trials in progress at the BMRR.

  16. Audits for advanced treatment dosimetry

    NASA Astrophysics Data System (ADS)

    Ibbott, G. S.; Thwaites, D. I.

    2015-01-01

    Radiation therapy has advanced rapidly over the last few decades, progressing from 3D conformal treatment to image-guided intensity modulated therapy of several different flavors, both 3D and 4D and to adaptive radiotherapy. The use of intensity modulation has increased the complexity of quality assurance and essentially eliminated the physicist's ability to judge the validity of a treatment plan, even approximately, on the basis of appearance and experience. Instead, complex QA devices and procedures are required at the institutional level. Similarly, the assessment of treatment quality through remote and on-site audits also requires greater sophistication. The introduction of 3D and 4D dosimetry into external audit systems must follow, to enable quality assurance systems to perform meaningful and thorough audits.

  17. The world first two cases of severe fever with thrombocytopenia syndrome: An epidemiological study in Nagasaki, Japan.

    PubMed

    Kurihara, Shintaro; Satoh, Akira; Yu, Fuxun; Hayasaka, Daisuke; Shimojima, Masayuki; Tashiro, Masato; Saijo, Tomomi; Takazono, Takahiro; Imamura, Yoshifumi; Miyazaki, Taiga; Tsukamoto, Misuzu; Yanagihara, Katsunori; Mukae, Hiroshi; Saijo, Masayuki; Morita, Kouichi; Kohno, Shigeru; Izumikawa, Koichi

    2016-07-01

    Severe fever with thrombocytopenia syndrome (SFTS) caused by the SFTS virus (SFTSV), a novel phlebovirus belonging to the family Bunyaviridae, was reported in China for the first time in 2009. We observed two cases where the SFTSV was isolated for the first time in Nagasaki, Japan, in 2005. Two males in their 60s, a farmer and a hunter, respectively, living in Nagasaki developed SFTS during the same period. The patients developed similar clinical symptoms and signs, such as fever, loss of consciousness, and multiple organ dysfunction. The farmer died and the hunter survived. A retrospective diagnosis of SFTS was made in 2013, and genetic analysis revealed that the patients were infected with different SFTSV strains. Retrospective analysis of cytokine production in non-fatal case revealed interleukin (IL)-6, IL-8 and interferon-γ level of acute phase was low and could be potential prognostic factors. As there are no epidemiological studies of positive rate of SFTSV antibody in people living in endemic areas in Japan, a field study was performed. Volunteers at high risk for tick bites, such as hunters, farmers, and soldiers, were recruited in 6 regions, including the areas where the SFTS cases occurred. Three hundred and twenty six volunteers in Nagasaki prefecture were examined and none of these tested positive for the SFTSV antibody. Our data indicates that the risk for SFTSV infection is not high in Nagasaki prefecture. Further collection of blood samples from endemic areas is warranted for the prevention of SFTSV infection. PMID:27142979

  18. Cosmic Ray Dosimetry

    NASA Astrophysics Data System (ADS)

    Si Belkhir, F.; Attallah, R.

    2010-10-01

    Radiation levels at aircraft cruising altitudes are twenty times higher than at sea level. Thus, on average, a typical airline pilot receives a larger annual radiation dose than some one working in nuclear industry. The main source of this radiation is from galactic cosmic radiation, high energy particles generated by exploding stars within our own galaxy. In this work we study cosmic rays dosimetry at various aviation altitudes using the PARMA model.

  19. Comparison of Real-Time Intraoperative Ultrasound-Based Dosimetry With Postoperative Computed Tomography-Based Dosimetry for Prostate Brachytherapy

    SciTech Connect

    Nag, Subir; Shi Peipei; Liu Bingren; Gupta, Nilendu; Bahnson, Robert R.; Wang, Jian Z.

    2008-01-01

    Purpose: To evaluate whether real-time intraoperative ultrasound (US)-based dosimetry can replace conventional postoperative computed tomography (CT)-based dosimetry in prostate brachytherapy. Methods and Materials: Between December 2001 and November 2002, 82 patients underwent {sup 103}Pd prostate brachytherapy. An interplant treatment planning system was used for real-time intraoperative transrectal US-guided treatment planning. The dose distribution was updated according to the estimated seed position to obtain the dose-volume histograms. Postoperative CT-based dosimetry was performed a few hours later using the Theraplan-Plus treatment planning system. The dosimetric parameters obtained from the two imaging modalities were compared. Results: The results of this study revealed correlations between the US- and CT-based dosimetry. However, large variations were found in the implant-quality parameters of the two modalities, including the doses covering 100%, 90%, and 80% of the prostate volume and prostate volumes covered by 100%, 150%, and 200% of the prescription dose. The mean relative difference was 38% and 16% for doses covering 100% and 90% of the prostate volume and 10% and 21% for prostate volumes covered by 100% and 150% of the prescription dose, respectively. The CT-based volume covered by 200% of the prescription dose was about 30% greater than the US-based one. Compared with CT-based dosimetry, US-based dosimetry significantly underestimated the dose to normal organs, especially for the rectum. The average US-based maximal dose and volume covered by 100% of the prescription dose for the rectum was 72 Gy and 0.01 cm{sup 3}, respectively, much lower than the 159 Gy and 0.65 cm{sup 3} obtained using CT-based dosimetry. Conclusion: Although dosimetry using intraoperative US-based planning provides preliminary real-time information, it does not accurately reflect the postoperative CT-based dosimetry. Until studies have determined whether US-based dosimetry

  20. TOPICAL REVIEW Dosimetry for ion beam radiotherapy

    NASA Astrophysics Data System (ADS)

    Karger, Christian P.; Jäkel, Oliver; Palmans, Hugo; Kanai, Tatsuaki

    2010-11-01

    Recently, ion beam radiotherapy (including protons as well as heavier ions) gained considerable interest. Although ion beam radiotherapy requires dose prescription in terms of iso-effective dose (referring to an iso-effective photon dose), absorbed dose is still required as an operative quantity to control beam delivery, to characterize the beam dosimetrically and to verify dose delivery. This paper reviews current methods and standards to determine absorbed dose to water in ion beam radiotherapy, including (i) the detectors used to measure absorbed dose, (ii) dosimetry under reference conditions and (iii) dosimetry under non-reference conditions. Due to the LET dependence of the response of films and solid-state detectors, dosimetric measurements are mostly based on ion chambers. While a primary standard for ion beam radiotherapy still remains to be established, ion chamber dosimetry under reference conditions is based on similar protocols as for photons and electrons although the involved uncertainty is larger than for photon beams. For non-reference conditions, dose measurements in tissue-equivalent materials may also be necessary. Regarding the atomic numbers of the composites of tissue-equivalent phantoms, special requirements have to be fulfilled for ion beams. Methods for calibrating the beam monitor depend on whether passive or active beam delivery techniques are used. QA measurements are comparable to conventional radiotherapy; however, dose verification is usually single field rather than treatment plan based. Dose verification for active beam delivery techniques requires the use of multi-channel dosimetry systems to check the compliance of measured and calculated dose for a representative sample of measurement points. Although methods for ion beam dosimetry have been established, there is still room for developments. This includes improvement of the dosimetric accuracy as well as development of more efficient measurement techniques.

  1. Develop real-time dosimetry concepts and instrumentation for long term missions

    NASA Technical Reports Server (NTRS)

    Braby, L. A.

    1981-01-01

    The development of a rugged portable dosimetry system, based on microdosimetry techniques, which will measure dose and evaluate dose equivalent in a mixed radiation field is described. Progress in the desired dosimetry system can be divided into three distinct areas: development of the radiation detector, and electron system are presented. The mathematical techniques required are investigated.

  2. Evaluation of radiochromic gel dosimetry and polymer gel dosimetry in a clinical dose verification

    NASA Astrophysics Data System (ADS)

    Vandecasteele, Jan; De Deene, Yves

    2013-09-01

    A quantitative comparison of two full three-dimensional (3D) gel dosimetry techniques was assessed in a clinical setting: radiochromic gel dosimetry with an in-house developed optical laser CT scanner and polymer gel dosimetry with magnetic resonance imaging (MRI). To benchmark both gel dosimeters, they were exposed to a 6 MV photon beam and the depth dose was compared against a diamond detector measurement that served as golden standard. Both gel dosimeters were found accurate within 4% accuracy. In the 3D dose matrix of the radiochromic gel, hotspot dose deviations up to 8% were observed which are attributed to the fabrication procedure. The polymer gel readout was shown to be sensitive to B0 field and B1 field non-uniformities as well as temperature variations during scanning. The performance of the two gel dosimeters was also evaluated for a brain tumour IMRT treatment. Both gel measured dose distributions were compared against treatment planning system predicted dose maps which were validated independently with ion chamber measurements and portal dosimetry. In the radiochromic gel measurement, two sources of deviations could be identified. Firstly, the dose in a cluster of voxels near the edge of the phantom deviated from the planned dose. Secondly, the presence of dose hotspots in the order of 10% related to inhomogeneities in the gel limit the clinical acceptance of this dosimetry technique. Based on the results of the micelle gel dosimeter prototype presented here, chemical optimization will be subject of future work. Polymer gel dosimetry is capable of measuring the absolute dose in the whole 3D volume within 5% accuracy. A temperature stabilization technique is incorporated to increase the accuracy during short measurements, however keeping the temperature stable during long measurement times in both calibration phantoms and the volumetric phantom is more challenging. The sensitivity of MRI readout to minimal temperature fluctuations is demonstrated which

  3. SU-E-J-164: An Investigation of a Low-Cost ‘dry’ Optical-CT Scanning System for 3D Dosimetry

    SciTech Connect

    Bache, S; Malcolm, J; Adamovics, J; Oldham, M

    2014-06-01

    Purpose: To characterize and explore the efficacy of a novel low-cost, lowfluid, broad-beam optical-CT system for 3D-dosimetry in radiochromic Presage dosimeters. Leading current optical-CT systems incorporate expensive glass-based telecentric lens technology, and a fluid bath with substantial amounts of fluid (which introduces an inconvenience factor) to minimize refraction artifacts. Here we introduce a novel system which addresses both these limitations by: (1) the use of Fresnel lenses in a telecentric arrangement, and (2) a ‘solid’ fluid bath which dramatically reduces the amount of fluid required for refractive-index (RI) matching. Materials Methods: A fresnel based telecentric optical-CT system was constructed which expands light from a single red LED source into a nominally parallel beam into which a cubic ‘dry-tank’ is placed. The drytank consists of a solid polyurethane cube (with the same RI as Presage) but containing a cylindrical cavity (11.5cm diameter × 11cm ) into which the dosimeter is placed for imaging. A narrow (1-3mm) gap between the walls of the dosimeter and dry-tank is filled with a fluid of similar RI. This arrangement reduces the amount of RI fluid from about 1000cc to 75cc, yielding substantial practical benefit in convenience and cost. The new system was evaluated in direct comparison against Eclipse planning system from a 4-field parallel-opposed treatmen Results: Gamma calculations of dose from DFOS-dry system versus Eclipse showed 92% and 97% agreement with 4mm/4% and 5mm/5% criteria, respectively, in the central 80% of dose distribution. Reconstructions showed some edge artifacts, as well as some dose underestimation towards the dosimeter edge. Conclusion: The implementation of Fresnel based ‘dry’ optical-CT for 3Ddosimetry would represent an important advance enhancing costeffectiveness and practical viability. The performance of the prototype presented here is not yet comparable to the state-of-the-art, but shows

  4. Development of an algorithm for TLD badge system for dosimetry in the field of X and gamma radiation in terms of Hp(10).

    PubMed

    Bakshi, A K; Srivastava, K; Varadharajan, G; Pradhan, A S; Kher, R K

    2007-01-01

    In view of the introduction of International Commission on Radiation Units and Measurements operational quantities Hp(10) and Hp(0.07), defined for individual monitoring, it became necessary to develop an algorithm that gives direct response of the dosemeter in terms of the operational quantities. Hence, for this purpose and also to improve the accuracy in dose estimation especially in the mixed fields of X ray and gamma, an algorithm was developed based on higher-order polynomial fit of the data points generated from the dose-response of discs under different filter regions of the present TL dosemeter system for known delivered doses. Study on the response of the BARC TL dosemeter system based on CaSO(4):Dy Teflon thermoluminescence dosemeter discs in the mixed fields of X and gamma radiation was carried out to ensure that the accuracies are within the prescribed limits recommended by the international organisations. The prevalent algorithm, based on the ratios of the disc response under various filters regions of the dosemeter to pure photons, was tested for different proportion of two radiations in case of mixed field dosimetry. It was found that the accuracy for few fields is beyond the acceptable limit in case of prevalent algorithm. The new proposed algorithm was also tested in mixed fields of photon fields and to pure photon fields of varied angles. It was found that the response of the dosemeter in mixed fields of photons and its angular response are satisfactory. The new algorithm can be used to record and report the personal dose in terms of Hp(10) as per the international recommendation for the present TL dosemeter. PMID:16984896

  5. FURTHER STUDIES ON UNCERTAINTY, CONFOUNDING, AND VALIDATION OF THE DOSES IN THE TECHA RIVER DOSIMETRY SYSTEM: Concluding Progress Report on the Second Phase of Project 1.1

    SciTech Connect

    Degteva, M. O.; Anspaugh, L. R.; Napier, Bruce A.

    2009-10-23

    This is the concluding Progress Report for Project 1.1 of the U.S./Russia Joint Coordinating Committee on Radiation Effects Research (JCCRER). An overwhelming majority of our work this period has been to complete our primary obligation of providing a new version of the Techa River Dosimetry System (TRDS), which we call TRDS-2009D; the D denotes deterministic. This system provides estimates of individual doses to members of the Extended Techa River Cohort (ETRC) and post-natal doses to members of the Techa River Offspring Cohort (TROC). The latter doses were calculated with use of the TRDS-2009D. The doses for the members of the ETRC have been made available to the American and Russian epidemiologists in September for their studies in deriving radiogenic risk factors. Doses for members of the TROC are being provided to European and Russian epidemiologists, as partial input for studies of risk in this population. Two of our original goals for the completion of this nine-year phase of Project 1.1 were not completed. These are completion of TRDS-2009MC, which was to be a Monte Carlo version of TRDS-2009 that could be used for more explicit analysis of the impact of uncertainty in doses on uncertainty in radiogenic risk factors. The second incomplete goal was to be the provision of household specific external doses (rather than village average). This task was far along, but had to be delayed due to the lead investigator’s work on consideration of a revised source term.

  6. The International Reactor Dosimetry File.

    Energy Science and Technology Software Center (ESTSC)

    1994-01-19

    Version 01 The International Reactor Dosimetry File (IRDF-90) contains recommended neutron cross-section data to be used for reactor neutron dosimetry by foil activation. It also contains selected recommended values for radiation damage cross-sections and benchmark neutron spectra. This library supersedes all earlier versions of IRDF.

  7. The Hiroshima and Nagasaki bombs: role-play and students' interest in physics

    NASA Astrophysics Data System (ADS)

    Heise Kofoed, Mikkel

    2006-11-01

    Role-play as a way of teaching is seldom used in physics. One reason is that role-play is usually constructed so as to contain some sort of conflict and conflicts do not often appear in the course of normal physics teaching. When it comes to the role of physics in war, role-play is an ideal way of presenting content to students. By taking part in role-play students become actively engaged in the teaching situation, developing their interest in physics. They also get a chance to understand the ethical issues involved. This article presents an example of a role-play based educational programme concerning the development of, the decisions behind, and the use of the Hiroshima and Nagasaki bombs during World War II. Some early research results are presented from evaluating the educational programme in lower and upper secondary schools in Denmark.

  8. Calculation and interpretation of In-Situ measurements of initial radiations at Hiroshima and Nagasaki

    SciTech Connect

    Loewe, W.E.

    1983-02-16

    Cobalt activation calculations will be reviewed, and similar comparisons of sulfur activation interior to electrical insulators on power transmission lines will be discussed. The relationship between neutron tissue kermas one to two kilometers from hypocenter and the particular activations of cobalt and sulfur are reviewed. At present, measured and calculated quantities agree within associated uncertainties, which are substantial. Additional work to shrink these uncertainties will be discussed. Particular cobalt activation topics will include: the sensitivity to thermal neutrons outside the pillar; calculated values using actual Nagasaki concrete composition; and calculational advances to improve modelling of the actual configuration. Particular sulfur activation topics will include: absolute comparisons of measured and calculated ratios of dpm/gm of /sup 32/P at all measured ranges, based on approximate experimental values for insulator attentuation and source radiations; the relationship between sulfur activation within a kilometer of hypocenter and kermas at two kilometers; and calculational advances to improve modelling of the actual configuration.

  9. Quasi 3D dosimetry (EPID, conventional 2D/3D detector matrices)

    NASA Astrophysics Data System (ADS)

    Bäck, A.

    2015-01-01

    Patient specific pretreatment measurement for IMRT and VMAT QA should preferably give information with a high resolution in 3D. The ability to distinguish complex treatment plans, i.e. treatment plans with a difference between measured and calculated dose distributions that exceeds a specified tolerance, puts high demands on the dosimetry system used for the pretreatment measurements and the results of the measurement evaluation needs a clinical interpretation. There are a number of commercial dosimetry systems designed for pretreatment IMRT QA measurements. 2D arrays such as MapCHECK® (Sun Nuclear), MatriXXEvolution (IBA Dosimetry) and OCTAVIOUS® 1500 (PTW), 3D phantoms such as OCTAVIUS® 4D (PTW), ArcCHECK® (Sun Nuclear) and Delta4 (ScandiDos) and software for EPID dosimetry and 3D reconstruction of the dose in the patient geometry such as EPIDoseTM (Sun Nuclear) and Dosimetry CheckTM (Math Resolutions) are available. None of those dosimetry systems can measure the 3D dose distribution with a high resolution (full 3D dose distribution). Those systems can be called quasi 3D dosimetry systems. To be able to estimate the delivered dose in full 3D the user is dependent on a calculation algorithm in the software of the dosimetry system. All the vendors of the dosimetry systems mentioned above provide calculation algorithms to reconstruct a full 3D dose in the patient geometry. This enables analyzes of the difference between measured and calculated dose distributions in DVHs of the structures of clinical interest which facilitates the clinical interpretation and is a promising tool to be used for pretreatment IMRT QA measurements. However, independent validation studies on the accuracy of those algorithms are scarce. Pretreatment IMRT QA using the quasi 3D dosimetry systems mentioned above rely on both measurement uncertainty and accuracy of calculation algorithms. In this article, these quasi 3D dosimetry systems and their use in patient specific pretreatment IMRT

  10. Characterization of a fiber-coupled Al{sub 2}O{sub 3}:C luminescence dosimetry system for online in vivo dose verification during {sup 192}Ir brachytherapy

    SciTech Connect

    Andersen, Claus E.; Nielsen, Soeren Kynde; Greilich, Steffen; Helt-Hansen, Jakob; Lindegaard, Jacob Christian; Tanderup, Kari

    2009-03-15

    A prototype of a new dose-verification system has been developed to facilitate prevention and identification of dose delivery errors in remotely afterloaded brachytherapy. The system allows for automatic online in vivo dosimetry directly in the tumor region using small passive detector probes that fit into applicators such as standard needles or catheters. The system measures the absorbed dose rate (0.1 s time resolution) and total absorbed dose on the basis of radioluminescence (RL) and optically stimulated luminescence (OSL) from aluminum oxide crystals attached to optical fiber cables (1 mm outer diameter). The system was tested in the range from 0 to 4 Gy using a solid-water phantom, a Varian GammaMed Plus {sup 192}Ir PDR afterloader, and dosimetry probes inserted into stainless-steel brachytherapy needles. The calibrated system was found to be linear in the tested dose range. The reproducibility (one standard deviation) for RL and OSL measurements was 1.3%. The measured depth-dose profiles agreed well with the theoretical expectations computed with the EGSNRC Monte Carlo code, suggesting that the energy dependence for the dosimeter probes (relative to water) is less than 6% for source-to-probe distances in the range of 2-50 mm. Under certain conditions, the RL signal could be greatly disturbed by the so-called stem signal (i.e., unwanted light generated in the fiber cable upon irradiation). The OSL signal is not subject to this source of error. The tested system appears to be adequate for in vivo brachytherapy dosimetry.