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Sample records for 60co internal dosimetry

  1. A review of the (60)Co internal dosimetry at Devonport Royal Dockyard.

    PubMed

    Vickers, J M A; Collison, R; Collision, R

    2010-03-01

    The physico-chemical properties of (60)Co contaminants arising from the UK Naval Nuclear Propulsion Programme (NNPP) pressurised water reactor (PWR) plants have been investigated in order to review individual monitoring requirements at Devonport Royal Dockyard (DRD). This has been achieved through laboratory tests on NNPP primary component samples and interpretation of direct bioassay measurements using internal dosimetry modelling software. Interpretation of lung measurements was completed for two inhalation events involving material originating from a PWR plant and post-primary circuit decontamination. Initial estimates of intake and dose were calculated using International Commission on Radiological Protection default parameter values. However, a good fit could only be achieved by fitting the data to alternative absorption parameters where 90-95% of the material dissolved and absorbed rapidly at a rate of 1 day(-1). As a consequence of this review, a number of improvements have been made to monitoring arrangements at DRD. A minimum of three direct measurements are now taken during the 0-30 day period after an intake, the capability of the Canberra Accuscan has been enhanced and dissolution tests are being carried out by the Health Protection Agency (HPA) on samples taken from PWR plants. PMID:20220215

  2. Monte Carlo Dosimetry of the 60Co BEBIG High Dose Rate for Brachytherapy

    PubMed Central

    Campos, Luciana Tourinho; de Almeida, Carlos Eduardo Veloso

    2015-01-01

    Introduction The use of high-dose-rate brachytherapy is currently a widespread practice worldwide. The most common isotope source is 192Ir, but 60Co is also becoming available for HDR. One of main advantages of 60Co compared to 192Ir is the economic and practical benefit because of its longer half-live, which is 5.27 years. Recently, Eckert & Ziegler BEBIG, Germany, introduced a new afterloading brachytherapy machine (MultiSource®); it has the option to use either the 60Co or 192Ir HDR source. The source for the Monte Carlo calculations is the new 60Co source (model Co0.A86), which is referred to as the new BEBIG 60Co HDR source and is a modified version of the 60Co source (model GK60M21), which is also from BEBIG. Objective and Methods The purpose of this work is to obtain the dosimetry parameters in accordance with the AAPM TG-43U1 formalism with Monte Carlo calculations regarding the BEBIG 60Co high-dose-rate brachytherapy to investigate the required treatment-planning parameters. The geometric design and material details of the source was provided by the manufacturer and was used to define the Monte Carlo geometry. To validate the source geometry, a few dosimetry parameters had to be calculated according to the AAPM TG-43U1 formalism. The dosimetry studies included the calculation of the air kerma strength Sk, collision kerma in water along the transverse axis with an unbounded phantom, dose rate constant and radial dose function. The Monte Carlo code system that was used was EGSnrc with a new cavity code, which is a part of EGS++ that allows calculating the radial dose function around the source. The spectrum to simulate 60Co was composed of two photon energies, 1.17 and 1.33 MeV. Only the gamma part of the spectrum was used; the contribution of the electrons to the dose is negligible because of the full absorption by the stainless-steel wall around the metallic 60Co. The XCOM photon cross-section library was used in subsequent simulations, and the

  3. A new standard cylindrical graphite-walled ionization chamber for dosimetry in 60Co beams at calibration laboratories

    NASA Astrophysics Data System (ADS)

    Neves, Lucio P.; Perini, Ana P.; Caldas, Linda V. E.

    2014-11-01

    60Co sources are used mostly at dosimetry laboratories for calibration of ionization chambers utilized for radiotherapy dosimetry, mainly in those laboratories where there is no linear accelerator available. In this work, a new cylindrical ionization chamber was developed and characterized to be used as a reference dosimeter at the Calibration Laboratory of the IPEN. The characterization tests were performed according to the IEC 60731 standard, and all tests presented results within its recommended limits. Furthermore, the correction factors for the wall, stem, central collecting electrode, nonaxial uniformity and the mass-energy absorption coefficient were determined using the EGSnrc Monte Carlo code. The air kerma rate determined with this new dosimeter was compared to the one obtained with the IPEN standard, presenting a difference of 1.5%. Therefore, the new ionization chamber prototype developed and characterized in this work presents potential use as a primary standard dosimeter at radiation metrology laboratories.

  4. Technical basis for internal dosimetry at Hanford

    SciTech Connect

    Sula, M.J.; Carbaugh, E.H.; Bihl, D.E.

    1991-07-01

    The Hanford Internal Dosimetry Program, administered by Pacific Northwest Laboratory for the US Department of Energy, provides routine bioassay monitoring for employees who are potentially exposed to radionuclides in the workplace. This report presents the technical basis for routine bioassay monitoring and the assessment of internal dose at Hanford. The radionuclides of concern include tritium, corrosion products ({sup 58}Co, {sup 60}Co, {sup 54}Mn, and {sup 59}Fe), strontium, cesium, iodine, europium, uranium, plutonium, and americium,. Sections on each of these radionuclides discuss the sources and characteristics; dosimetry; bioassay measurements and monitoring; dose measurement, assessment, and mitigation and bioassay follow-up treatment. 78 refs., 35 figs., 115 tabs.

  5. Technical basis for internal dosimetry at Hanford

    SciTech Connect

    Sula, M.J.; Carbaugh, E.H.; Bihl, D.E.

    1989-04-01

    The Hanford Internal Dosimetry Program, administered by Pacific Northwest Laboratory for the US Department of Energy, provides routine bioassay monitoring for employees who are potentially exposed to radionuclides in the workplace. This report presents the technical basis for routine bioassay monitoring and the assessment of internal dose at Hanford. The radionuclides of concern include tritium, corrosion products (/sup 58/Co, /sup 60/Co, /sup 54/Mn, and /sup 59/Fe), strontium, cesium, iodine, europium, uranium, plutonium, and americium. Sections on each of these radionuclides discuss the sources and characteristics; dosimetry; bioassay measurements and monitoring; dose measurement, assessment, and mitigation; and bioassay follow-up treatment. 64 refs., 42 figs., 118 tabs.

  6. Optically stimulated luminescence in vivo dosimetry for radiotherapy: physical characterization and clinical measurements in (60)Co beams.

    PubMed

    Mrčela, I; Bokulić, T; Izewska, J; Budanec, M; Fröbe, A; Kusić, Z

    2011-09-21

    A commercial optically stimulated luminescence (OSL) dosimetry system was investigated for in vivo dosimetry in radiation therapy. Dosimetric characteristics of InLight dot dosimeters and a microStar reader (Landauer Inc.) were tested in (60)Co beams. The reading uncertainty of a single dosimeter was 0.6%. The reproducibility of a set of dosimeters after a single irradiation was 1.6%, while in repeated irradiations of the same dosimeters it was found to be 3.5%. When OSL dosimeters were optically bleached between exposures, the reproducibility of repeated measurements improved to 1.0%. Dosimeters were calibrated for the entrance dose measurements and a full set of correction factors was determined. A pilot patient study that followed phantom validation testing included more than 100 measured fields with a mean relative difference of the measured entrance dose from the expected dose of 0.8% and the standard deviation of 2.5%. In conclusion, these results demonstrate that OSL dot dosimeters represent a valid alternative to already established in vivo dosimetry systems. PMID:21873767

  7. 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.

  8. 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.

  9. Application of a color scanner for 60Co high dose rate brachytherapy dosimetry with EBT radiochromic film

    PubMed Central

    Ghorbani, Mahdi; Toossi, Mohammad Taghi Bahreyni; Mowlavi, Ali Asghar; Roodi, Shahram Bayani; Meigooni, Ali Soleimani

    2012-01-01

    Background. The aim of this study is to evaluate the performance of a color scanner as a radiochromic film reader in two dimensional dosimetry around a high dose rate brachytherapy source. Materials and methods A Microtek ScanMaker 1000XL film scanner was utilized for the measurement of dose distribution around a high dose rate GZP6 60Co brachytherapy source with GafChromic® EBT radiochromic films. In these investigations, the non-uniformity of the film and scanner response, combined, as well as the films sensitivity to scanner’s light source was evaluated using multiple samples of films, prior to the source dosimetry. The results of these measurements were compared with the Monte Carlo simulated data using MCNPX code. In addition, isodose curves acquired by radiochromic films and Monte Carlo simulation were compared with those provided by the GZP6 treatment planning system. Results Scanning of samples of uniformly irradiated films demonstrated approximately 2.85% and 4.97% nonuniformity of the response, respectively in the longitudinal and transverse directions of the film. Our findings have also indicated that the film response is not affected by the exposure to the scanner’s light source, particularly in multiple scanning of film. The results of radiochromic film measurements are in good agreement with the Monte Carlo calculations (4%) and the corresponding dose values presented by the GZP6 treatment planning system (5%). Conclusions The results of these investigations indicate that the Microtek ScanMaker 1000XL color scanner in conjunction with GafChromic EBT film is a reliable system for dosimetric evaluation of a high dose rate brachytherapy source. PMID:23411947

  10. International intercomparison for criticality dosimetry: the case of biological dosimetry.

    PubMed

    Roy, L; Buard, V; Delbos, M; Durand, V; Paillole, N; Grégoire, E; Voisin, P

    2004-01-01

    The Institute of Radiation Protection and Nuclear Safety (IRSN) organized a biological dosimetry international intercomparison with the purpose of comparing (i) dicentrics yield produced in human lymphocytes; (ii) the gamma and neutron dose estimate according to the corresponding laboratory calibration curve. The experimental reactor SILENE was used with different configurations: bare source 4 Gy, lead shield 1 and 2 Gy and a 60Co source 2 Gy. An increasing variation of dicentric yield per cell was observed between participants when there were more damages in the samples. Doses were derived from the observed dicentric rates according to the dose-effect relationship provided by each laboratory. Differences in dicentric rate values are more important than those in the corresponding dose values. The doses obtained by the participants were found to be in agreement with the given physical dose within 20%. The evaluation of the respective gamma and neutron dose was achieved only by four laboratories, with some small variations among them. PMID:15353693

  11. An analytic approach to the dosimetry of a new BEBIG 60Co high-dose-rate brachytherapy source

    PubMed Central

    Bhola, Subhalaxmi; Selvam, T. Palani; Sridhar, Sahoo; Vishwakarma, Ramkrishna S.

    2012-01-01

    We present a simple analytic tool for calculating the dose rate distribution in water for a new BEBIG high-dose-rate (HDR) 60Co brachytherapy source. In the analytic tool, we consider the active source as a point located at the geometric center of the 60Co material. The influence of the activity distribution in the active volume of the source is taken into account separately by use of the line source-based geometric function. The exponential attenuation of primary 60Co photons by the source materials (60Co and stainless-steel) is included in the model. The model utilizes the point-source-based function, f(r) that represents the combined effect of the exponential attenuation and scattered photons in water. We derived this function by using the published radial dose function for a point 60Co source in an unbounded water medium of radius 50 cm. The attenuation coefficients for 60Co and the stainless-steel encapsulation materials are deduced as best-fit parameters that minimize the different PMID:22973079

  12. Hanford internal dosimetry program manual

    SciTech Connect

    Carbaugh, E.H.; Sula, M.J.; Bihl, D.E.; Aldridge, T.L.

    1989-10-01

    This document describes the Hanford Internal Dosimetry program. Program Services include administrating the bioassay monitoring program, evaluating and documenting assessments of internal exposure and dose, ensuring that analytical laboratories conform to requirements, selecting and applying appropriate models and procedures for evaluating internal radionuclide deposition and the resulting dose, and technically guiding and supporting Hanford contractors in matters regarding internal dosimetry. 13 refs., 16 figs., 42 tabs.

  13. 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.

  14. 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.

  15. Internal dosimetry technical basis manual

    SciTech Connect

    Not Available

    1990-12-20

    The internal dosimetry program at the Savannah River Site (SRS) consists of radiation protection programs and activities used to detect and evaluate intakes of radioactive material by radiation workers. Examples of such programs are: air monitoring; surface contamination monitoring; personal contamination surveys; radiobioassay; and dose assessment. The objectives of the internal dosimetry program are to demonstrate that the workplace is under control and that workers are not being exposed to radioactive material, and to detect and assess inadvertent intakes in the workplace. The Savannah River Site Internal Dosimetry Technical Basis Manual (TBM) is intended to provide a technical and philosophical discussion of the radiobioassay and dose assessment aspects of the internal dosimetry program. Detailed information on air, surface, and personal contamination surveillance programs is not given in this manual except for how these programs interface with routine and special bioassay programs.

  16. The International Reactor Dosimetry File.

    Energy Science and Technology Software Center (ESTSC)

    2008-08-07

    Version 01 The International Reactor Dosimetry File (IRDF-2002) contains recommended neutron cross-section data to be used for reactor neutron dosimetry by foil activation and subsequent neutron spectrum unfolding. It also contains selected recom�mended values for radiation damage cross-sections and benchmark neutron spectra. Two related programs available from NEADB and RSICC are: SPECTER-ANL (PSR-263) & STAY’SL (PSR-113).

  17. Consistency in reference radiotherapy dosimetry: resolution of an apparent conundrum when 60Co is the reference quality for charged-particle and photon beams

    NASA Astrophysics Data System (ADS)

    Andreo, Pedro; Wulff, Jörg; Burns, David T.; Palmans, Hugo

    2013-10-01

    Substantial changes in ion chamber perturbation correction factors in 60Co γ-rays, suggested by recent Monte Carlo (MC) calculations, would cause a decrease of about 1.5% in the reference dosimetry of all types of charged particles (electrons, protons and heavier ions) based on calculated kQ values. It has gone largely unnoticed that the ratio of calibration coefficients ND, w, Co60 and NK, air, Co60 yields an experimental value of Fch, Co60 = (sw-air pch)Co60 through ND, air, Co60. Coefficients provided by the IAEA and traceable to the BIPM for 91 NE-2571 chambers result in an average Fch, Co60 which is compared with published (and new) MC simulations and with the value in IAEA TRS-398. It is shown that TRS-398 agrees within 0.12% with the experimental Fch, Co60. The 1.5% difference resulting from MC calculations (1.1% for the new simulations) cannot be justified using current fundamental data and BIPM standards if consistency in the entire dosimetry chain is sought. For photons, MC kQ factors are compared with TRS-398. Using the same uncertainty for Wair, the two sets of data overlap considerably. Experimental kQ values from standards laboratories lie between the two sets of calculated values, showing no preference for one set over the other. Observed chamber-to-chamber differences, that include the effect of waterproof sleeves (also seen for 60Co), justify the recommendation in TRS-398 for kQ values specifically measured for the user chamber. Current developments on I-values for the stopping powers of water and graphite are presented. A weighted average Iwater = 78 ± 2 eV is obtained from published experimental and DRF-based values; this would decrease sw-air for all types of radiotherapy beams between 0.3% and 0.6%, and would consequently decrease the MC derived Fch, Co60. The implications of a recent proposal for Igraphite = 81 eV are analysed, resulting in a potential decrease of 0.7% in NK, air, Co60 which would raise the experimental Fch, Co60

  18. 4.2 Methods for Internal Dosimetry

    NASA Astrophysics Data System (ADS)

    Noßke, D.; Mattsson, S.; Johansson, L.

    This document is part of Subvolume A 'Fundamentals and Data in Radiobiology, Radiation Biophysics, Dosimetry and Medical Radiological Protection' of Volume 7 'Medical Radiological Physics' of Landolt-Börnstein - Group VIII 'Advanced Materials and Technologies'. It contains the Section '4.2 Methods for Internal Dosimetry' of the Chapter '4 Dosimetry in Nuclear Medicine Diagnosis and Therapy' with the contents:

  19. Biokinetics of systemically distributed 60Co in the rat: an experimental model useful in evaluating medical countermeasures for internal contamination.

    PubMed

    Weber, Waylon; Doyle-Eisele, Melanie; Seilkop, Steven K; Guilmette, Raymond

    2012-10-01

    LBERI, a member of the Medical Countermeasures to Radiologic Threats (MCART) consortium funded by NIAID, was tasked to develop biokinetic models for the distribution of radionuclide threats using the most likely routes of incorporation in both small and large animals. In this paper, the biokinetics of systemically administered soluble (60)Co have been examined. Male and female jugular-vein-catheterized (JVC) F344 rats received intravenous (IV) doses of 11.2 kBq of (60)CoCl2. The distribution of the radiocobalt was followed for 28 d with tissue sampling done at 1 and 4 h, and at 1, 2, 4, 8, 16, and 28 d. Urine and feces were collected daily. Tissues and excreta were analyzed by gamma pulse height analysis. Within 8 d, 93% of the cobalt was eliminated from the body, primarily though urine. The highest tissue burdens were found in the liver, gastrointestinal (GI) tract, and muscle shortly after administration. These tissues cleared quickly, so that by the conclusion of the 28-d study, less than 3% of the injected dose remained in the body. The results are comparable to published literature values for tissue content of (60)Co and for excretion patterns up to 30 d after injection. These results will provide the data needed to construct a biokinetic model for the unperturbed biokinetics of (60)Co in rats, which will subsequently be used to evaluate the impact of administered decorporating agents on organ radiation doses. The animal model described in this paper is representative of that used for other routes of radionuclide administration, such as inhalation, ingestion, and wound contamination, that have been studied at LBERI in support of the MCART and NIAID programs. PMID:22929473

  20. Fifth international radiopharmaceutical dosimetry symposium

    SciTech Connect

    Watson, E.E.; Schlafke-Stelson, A.T.

    1992-05-01

    This meeting was held to exchange information on how to get better estimates of the radiation absorbed dose. There seems to be a high interest of late in patient dosimetry; discussions were held in the light of revised risk estimates for radiation. Topics included: Strategies of Dose Assessment; Dose Estimation for Radioimmunotherapy; Dose Calculation Techniques and Models; Dose Estimation for Positron Emission Tomography (PET); Kinetics for Dose Estimation; and Small Scale Dosimetry and Microdosimetry. (VC)

  1. Methods and Models of the Hanford Internal Dosimetry Program, PNNL-MA-860

    SciTech Connect

    Carbaugh, Eugene H.; Bihl, Donald E.; Maclellan, Jay A.; Antonio, Cheryl L.; Hill, Robin L.

    2009-09-30

    The Hanford Internal Dosimetry Program (HIDP) provides internal dosimetry support services for operations at the Hanford Site. The HIDP is staffed and managed by the Radiation and Health Technology group, within the Pacific Northwest National Laboratory (PNNL). Operations supported by the HIDP include research and development, the decontamination and decommissioning of facilities formerly used to produce and purify plutonium, and waste management activities. Radioelements of particular interest are plutonium, uranium, americium, tritium, and the fission and activation product radionuclides 137Cs, 90Sr, and 60Co. This manual describes the technical basis for the design of the routine bioassay monitoring program and for assessment of internal dose. The purposes of the manual are as follows: • Provide assurance that the HIDP derives from a sound technical base. • Promote the consistency and continuity of routine program activities. • Provide a historical record. • Serve as a technical reference for radiation protection personnel. • Aid in identifying and planning for future needs.

  2. 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.

  3. Hanford Internal Dosimetry Project manual. Revision 1

    SciTech Connect

    Carbaugh, E.H.; Bihl, D.E.; MacLellan, J.A.; Long, M.P.

    1994-07-01

    This document describes the Hanford Internal Dosimetry Project, as it is administered by Pacific Northwest Laboratory (PNL) in support of the US Department of Energy and its Hanford contractors. Project services include administrating the bioassay monitoring program, evaluating and documenting assessment of potential intakes and internal dose, ensuring that analytical laboratories conform to requirements, selecting and applying appropriate models and procedures for evaluating radionuclide deposition and the resulting dose, and technically guiding and supporting Hanford contractors in matters regarding internal dosimetry. Specific chapters deal with the following subjects: practices of the project, including interpretation of applicable DOE Orders, regulations, and guidance into criteria for assessment, documentation, and reporting of doses; assessment of internal dose, including summary explanations of when and how assessments are performed; recording and reporting practices for internal dose; selection of workers for bioassay monitoring and establishment of type and frequency of bioassay measurements; capability and scheduling of bioassay monitoring services; recommended dosimetry response to potential internal exposure incidents; quality control and quality assurance provisions of the program.

  4. 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.

  5. a Generalized Program for Internal Radionuclide Dosimetry

    NASA Astrophysics Data System (ADS)

    Johnson, Timothy Karl

    The development of monoclonal antibodies specific for tumor surface antigens promises a highly specific carrier medium for delivering a tumorcidal radiation dose. Dosimetry calculations of monoclonal antibodies are made difficult, however, precisely because the focus of radioactivity is targeted for a nonstandard volume in a nonstandard geometry. This precludes straightforward application of the formalism developed for internal radionuclide dosimetry by the Medical Internal Radiation Dose Committee. A software program was written to account for the perturbations introduced by the inclusion of a tumor mass as an additional source of, and target for, radiation. The program allows the interactive development of a mathematical model to account for observed biodistribution data. The model describes the time dependence of radioactivity in each organ system that retains radiolabeled antibody, including tumor. Integration of these "time-activity" curves yield cumulative activity for each organ system identified as a 'source' of radioactivity. A Monte Carlo simulation of photon transport is then executed for each source organ to obtain the fraction of radiation energy absorbed by various 'target' organs. When combined with the cumulative activity, this absorbed fraction allows an estimate of dose to be made for each target organ. The program has been validated against ten analytic models designed to span a range of common input data types. Additionally, a performance benchmark has been defined to assess the practicality of implementing the program on different computing hardware platforms. Sources of error in the computation are elaborated on, and future directions and improvements discussed. The software presents an integrated modeling/dosimetry environment particularly suited for performing Monoclonal Antibody dosimetry. It offers a viable methodology for performing prospective treatment planning, based on extrapolation of tracer kinetic data to therapeutic levels.

  6. Maintaining the accuracy of the (60)Co calibration service at the ARPANSA post source replacement in 2010.

    PubMed

    Oliver, Chris; Butler, Duncan; Webb, David; Wright, Tracy; Lye, Jessica; Ramanathan, Ganesan; Harty, Peter; Takau, Viliami

    2015-06-01

    The Australian Radiation Protection and Nuclear Safety Agency (ARPANSA) maintains a (60)Co teletherapy source primarily for the calibration of therapy dosemeters. The source and encapsulating head were replaced in early 2010 with an Eldorado 78 head and new (60)Co source. In this article we present the results of ongoing accuracy and stability measurements since the replacement. A number of formal and informal indirect comparisons have been carried out with laboratories holding primary and secondary standards for (60)Co. ARPANSA chambers have also been calibrated at international primary standard laboratories allowing comparison of calibration coefficients and thus (60)Co absorbed dose standards. (60)Co calibration coefficients supplied by manufacturers of chambers were compared to those measured at the ARPANSA when this calibration was traceable to a primary standard. ARPANSA also participates in an annual international mailed dosimetry audit conducted by the International Atomic Energy Agency. The results thus far demonstrate that the absorbed doses to water delivered by the new ARPANSA (60)Co source are consistent with international doses within the stated uncertainties. PMID:25749989

  7. Hanford Internal Dosimetry Program Manual, PNL-MA-552

    SciTech Connect

    Carbaugh, Eugene H.; Bihl, Donald E.; Maclellan, Jay A.

    2003-10-10

    This manual is a guide to the services provided by the Hanford Internal Dosimetry Program (IDP). It describes the roles of and relationships between the IDP and site contractors, and provides recommendations and guidance for consideration in implementing bioassay monitoring and internal dosimetry elements of radiation protection programs. Guidance includes identifying conditions under which workers should be placed on bioassay programs, types, descritptions, and capabilities of measurements, suggested routine bioassay programs, limitations on services, and practices for recording and reporting results.

  8. Code for INternal DosimetrY

    Energy Science and Technology Software Center (ESTSC)

    2002-05-30

    The Code for Internal Dosimetry Software Package (CINDY1.4) was developed to assist in the interpretation of bioassay data, provide bioassay projections, and evaluate committed and calendar-year doses from intake or bioassay measurement data. CINDY1.4 addresses the U.S. Department of Energy's (DOE) Order 5480.11 and the U.S. Nuclear Regulatory Commission's (NRC) 10 CFR 20 by providing the capabilities to calculate organ dose equivalents and effective dose equivalents using the International Commission on radiological Protection (ICRP) 30more » approach. Biokinetic models, which allow user-modified parameter values, are used to estimate intakes based on bioassay data using weighted and unweighted least-squares regression between measured and expected bioassay values, to estimate organ burdens as well as urinary and fecal excretion rates from a given intake, and to determine organ doses for annual, 50-year, calendar year, or any other time point. Intakes to be considered may be either acute or chronic, and may consist of many combinations of intake routes, radionuclides, and physical and chemical forms. A four-compartment input model (with user defined parameters) is used for wounds and absorption. Direct injection can be simulated as direct absorption. Appropriate metabolic models for each radionuclide are selected by the user from menus. Metabolic models available in CINDY1.4 are the ICRP 30 lung model, ICRP 30 gastrointestinal model, ICRP 30 general systematic model, Johnson and Dunford tritium model, ICRP 30 tritium model, including the Johnson HT lung model, Johnson alkaline earth model, ICRP 54 iodine model, tellurium-iodine model, Jones excretion model, Durbin excretion model, ICRP 54 excretion models, Wrenn-Lipsztein uranium model, Fisher Modified Wrenn-Lipsztein uranium model, and the ICRP 30 carbon model. For Windows 95 or Windows NT an alternate CD is required.« less

  9. Distribution of 60Co in steel samples from Hiroshima.

    PubMed

    Hult, M; Marissens, G; Sahin, N; Hoshi, M; Hasai, H; Shizuma, K; Tanaka, K; Endo, S

    2012-09-01

    This paper describes ultra low-level gamma-ray spectrometry measurements of the (60)Co activity distribution inside one 52 mm and one 41 mm thick steel sample. The samples had been exposed to the Hiroshima atomic bomb and were from the Aioi bridge and the Yokogawa bridge. Both samples were measured in a recent study aiming to back up model calculation of Hiroshima dosimetry. The (60)Co activity distributions found in this study support the assumptions made in the previous study. PMID:22406217

  10. 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.

  11. 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

  12. Hanford Internal Dosimetry Program Manual, PNL-MA-552

    SciTech Connect

    Carbaugh, Eugene H.; Bihl, Donald E.; Maclellan, Jay A.

    2009-09-24

    This manual is a guide to the services provided by the Hanford Internal Dosimetry Program (IDP), which is operated by the Pacific Northwest National Laboratory.( ) for the U.S. Department of Energy Richland Operations Office, Office of River Protection and their Hanford Site contractors. The manual describes the roles of and relationships between the IDP and the radiation protection programs of the Hanford Site contractors. Recommendations and guidance are also provided for consideration in implementing bioassay monitoring and internal dosimetry elements of radiation protection programs.

  13. Integration of external and internal dosimetry in Switzerland.

    PubMed

    Frei, D; Wernli, C; Baechler, S; Fischer, G; Jossen, H; Leupin, A; Lörtscher, Y; Mini, R; Otto, T; Schuh, R; Weidmann, U

    2007-01-01

    Individual monitoring regulations in Switzerland are based on the ICRP60 recommendations. The annual limit of 20 mSv for the effective dose applies to the sum of external and internal radiation. External radiation is monitored monthly or quarterly with TLD, DIS or CR-39 dosemeters by 10 approved external dosimetry services and reported as Hp(10) and Hp(0.07). Internal monitoring is done in two steps. At the workplace, simple screening measurements are done frequently in order to recognise a possible incorporation. If a nuclide dependent activity threshold is exceeded then one of the seven approved dosimetry services for internal radiation does an incorporation measurement to assess the committed effective dose E50. The dosimetry services report all the measured or assessed dose values to the employer and to the National Dose Registry. The employer records the annually accumulated dose values into the individual dose certificate of the occupationally exposed person, both the external dose Hp(10) and the internal dose E50 as well as the total effective dose E=Hp(10)+E50. Based on the national dose registry an annual report on the dosimetry in Switzerland is published which contains the statistics for the total effective dose, as well as separate statistics for external and internal exposure. PMID:17287205

  14. BUILDING 122 CONTAINS THREE GENERAL AREAS: OFFICE AREAS, INTERNAL DOSIMETRY, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    BUILDING 122 CONTAINS THREE GENERAL AREAS: OFFICE AREAS, INTERNAL DOSIMETRY, AND MEDICAL/HEALTH. BUILDING 122 SHARES A COMMON WALL WITH BUILDING 121, THE PLANT SECURITY BUILDING. THE TWO-STORY BUILDING IN THE BACKGROUND IS BUILDING 111. (9/26/52) - Rocky Flats Plant, Emergency Medical Services Facility, Southwest corner of Central & Third Avenues, Golden, Jefferson County, CO

  15. Internal radiation dosimetry for clinical testing of radiolabeled monoclonal antibodies

    SciTech Connect

    Fisher, D.R.; Durham, J.S.; Hui, T.E.; Hill, R.L.

    1990-11-01

    In gauging the efficacy of radiolabeled monoclonal antibodies in cancer treatment, it is important to know the amount of radiation energy absorbed by tumors and normal tissue per unit administered activity. This paper describes methods for estimating absorbed doses to human tumors and normal tissues, including intraperitoneal tissue surfaces, red marrow, and the intestinal tract from incorporated radionuclides. These methods use the Medical Internal Radiation Dose (MIRD) scheme; however, they also incorporate enhancements designed to solve specific dosimetry problems encountered during clinical studies, such as patient-specific organ masses obtained from computerized tomography (CT) volumetrics, estimates of the dose to tumor masses within normal organs, and multicellular dosimetry for studying dose inhomogeneities in solid tumors. Realistic estimates of absorbed dose are provided within the short time requirements of physicians so that decisions can be made with regard to patient treatment and procurement of radiolabeled antibodies. Some areas in which further research could improve dose assessment are also discussed. 16 refs., 3 figs.

  16. Internal dosimetry monitoring equipment: Present and future

    SciTech Connect

    Selby, J.; Carbaugh, E.H.; Lynch, T.P.; Strom, D.J.; Lardy, M.M.

    1993-09-01

    We have attempted to characterize the current and future status of in vivo and in vitro measurement programs coupled with the associated radioanalytical methods and workplace monitoring. Developments in these areas must be carefully integrated by internal dosimetrists, radiochemists and field health physicists. Their goal should be uniform improvement rather than to focus on one specific area (e.g., dose modeling) to the neglect of other areas where the measurement capabilities are substantially less sophisticated and, therefore, the potential source of error is greatest.

  17. Effect of respiratory motion on internal radiation dosimetry

    SciTech Connect

    Xie, Tianwu; Zaidi, Habib

    2014-11-01

    Purpose: Estimation of the radiation dose to internal organs is essential for the assessment of radiation risks and benefits to patients undergoing diagnostic and therapeutic nuclear medicine procedures including PET. Respiratory motion induces notable internal organ displacement, which influences the absorbed dose for external exposure to radiation. However, to their knowledge, the effect of respiratory motion on internal radiation dosimetry has never been reported before. Methods: Thirteen computational models representing the adult male at different respiratory phases corresponding to the normal respiratory cycle were generated from the 4D dynamic XCAT phantom. Monte Carlo calculations were performed using the MCNP transport code to estimate the specific absorbed fractions (SAFs) of monoenergetic photons/electrons, the S-values of common positron-emitting radionuclides (C-11, N-13, O-15, F-18, Cu-64, Ga-68, Rb-82, Y-86, and I-124), and the absorbed dose of {sup 18}F-fluorodeoxyglucose ({sup 18}F-FDG) in 28 target regions for both the static (average of dynamic frames) and dynamic phantoms. Results: The self-absorbed dose for most organs/tissues is only slightly influenced by respiratory motion. However, for the lung, the self-absorbed SAF is about 11.5% higher at the peak exhale phase than the peak inhale phase for photon energies above 50 keV. The cross-absorbed dose is obviously affected by respiratory motion for many combinations of source-target pairs. The cross-absorbed S-values for the heart contents irradiating the lung are about 7.5% higher in the peak exhale phase than the peak inhale phase for different positron-emitting radionuclides. For {sup 18}F-FDG, organ absorbed doses are less influenced by respiratory motion. Conclusions: Respiration-induced volume variations of the lungs and the repositioning of internal organs affect the self-absorbed dose of the lungs and cross-absorbed dose between organs in internal radiation dosimetry. The dynamic

  18. Monte Carlo based voxel phantoms for in vivo internal dosimetry.

    PubMed

    Ros, J M Gómez; Moraleda, M; López, M A; Navarro, T; Navarro, J F

    2007-01-01

    The purpose of this communication is to describe briefly the computer programs developed to generate the MCNP input file corresponding to any segmented tomographic data and its application to the calibration procedures for in vivo internal dosimetry. The method has been applied to the determination of 241Am in bone by measurement in skull and knee using MCNP voxel models of a real human head and knee based on the tomographic Voxelman and Arms Down phantoms developed by Zubal et al. at Yale University. PMID:17449911

  19. Methods and Models of the Hanford Internal Dosimetry Program, PNNL-MA-860

    SciTech Connect

    Carbaugh, Eugene H.; Bihl, Donald E.; Maclellan, Jay A.

    2003-01-03

    This manual describes the technical basis for the design of the routine radiobioassay monitoring program and assessments of internal dose. Its purpose is to provide a historical record of the methods, models, and assumptions used for internal dosimetry at Hanford, and serve as a technical reference for radiation protection and dosimetry staff.

  20. 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

  1. Internal dosimetry performing dose assessments via bioassay measurements

    SciTech Connect

    Bailey, K.M.

    1993-05-11

    The Internal Dosimetry Department at the Y-12 Plant maintains a state-of-the-art bioassay program managed under the guidance and regulations of the Department of Energy. The two major bioassay techniques currently used at Y-12 are the in vitro (urinalysis) and in vivo (lung counting) programs. Fecal analysis (as part of the in vitro program) is another alternative; however, since both urine and fecal analysis provide essentially the same capabilities for detecting exposures to uranium, the urinalysis is the main choice primarily for aesthetic reasons. The bioassay frequency is based on meeting NCRP 87 objectives which are to monitor the accumulation of radioactive material in exposed individuals, and to ensure that significant depositions are detected.

  2. Code for internal dosimetry (CINDY): Part 1, Conceptual representation

    SciTech Connect

    Strenge, D.L.; Peloquin, R.A.; Sula, M.J.; Johnson, J.R.

    1990-10-01

    The computer code CINDY (Computerized Internal Dosimetry Software Package) has been developed by Pacific Northwest Laboratory to address the Department of Energy (DOE) Order 5480.11 by providing the capabilities to calculate organ dose equivalents and effective dose equivalents using the approach contained in International Commission on Radiological Protection (ICRP) Publication 30. The code assists in the interpretation of bioassay data, the evaluation of committed and calendar-year doses from intake or bioassay measurement data, and the preparation of reports, consistent with revised DOE orders. The code is easy to use and is generally applicable to DOE sites. Flexible biokinetics models are used to determine organ doses for annual, 50-year, calendar-year, or any other time-point dose necessary for chronic or acute intakes. The CINDY code is an interactive computer program that prompts the user to describe the cases to be analyzed and calculates the necessary results for the type of analysis being performed. 30 refs., 13 figs., 14 tabs.

  3. Current internal-dosimetry practices at US Department of Energy facilities

    SciTech Connect

    Traub, R.J.; Murphy, B.L.; Selby, J.M.; Vallario, E.J.

    1985-04-01

    The internal dosimetry practice at DOE facilities were characterized. The purpose was to determine the size of the facilities' internal dosimetry programs, the uniformity of the programs among the facilities, and the areas of greatest concern to health physicists in providing and reporting accurate estimates of internal radiation dose and in meeting proposed changes in internal dosimetry. The differences among the internal-dosimetry programs are related to the radioelements in use at each facility and, to some extent, the number of workers at each facility. The differences include different frequencies in the use of quality control samples, different minimum detection levels, different methods of recording radionuclides, different amounts of data recorded in the permanent record, and apparent differences in modeling the metabolism of radionuclides within the body. Recommendations for improving internal-dosimetry practices include studying the relationship between air-monitoring/survey readings and bioassay data, establishing uniform methods for recording bioassay results, developing more sensitive direct-bioassay procedures, establishing a mechanism for sharing information on internal-dosimetry procedures among DOE facilities, and developing mathematical models and interactive computer codes that can help quantify the uptake of radioactive materials and predict their distribution in the body. 19 refs., 8 tabs.

  4. 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.

  5. Internal dosimetry estimates using voxelized reference phantoms for thyroid agents

    PubMed Central

    Hoseinian-Azghadi, E.; Rafat-Motavalli, L.; Miri-Hakimabad, H.

    2014-01-01

    This work presents internal dosimetry estimates for diagnostic procedures performed for thyroid disorders by relevant radiopharmaceuticals. The organ doses for 131Iodine, 123Iodine and 99mTc incorporated into the body were calculated for the International Commission on Radiological Protection (ICRP) reference voxel phantoms using the Monte Carlo transport method. A comparison between different thyroid uptakes of iodine in the range of 0–55% was made, and the effect of various techniques for administration of 99mTc on organ doses was studied. To investigate the necessity of calculating organ dose from all source regions, the major source organ and its contribution to total dose were specified for each target organ. Moreover, we compared effective dose in ICRP voxel phantoms with that in stylized phantoms. In our method, we directly calculated the organ dose without using the S values or SAFs, as is commonly done. Hence, a distribution of the absorbed dose to entire tissues was obtained. The chord length distributions (CLDs) were also computed for the selected source–target pairs to make comparison across the genders. The results showed that the S values for radionuclides in the thyroid are not sufficient for calculating the organ doses, especially for 123I and 99mTc. The thyroid and its neighboring organs receive a greater dose as thyroid uptake increases. Our comparisons also revealed an underestimation of organ doses reported for the stylized phantoms compared with the values based on the ICRP voxel phantoms in the uptake range of 5–55%, and an overestimation of absorbed dose by up to 2-fold for Iodine administration using blocking agent and for 99mTc incorporation. PMID:24222311

  6. Reference dosimetry measurements for the international intercomparison of criticality accident dosimetry SILENE 9-21 June 2002.

    PubMed

    Asselineau, B; Trompier, F; Texier, C; Itié, C; Médioni, R; Tikunov, D; Muller, H; Pelcot, G

    2004-01-01

    An international intercomparison of criticality accident dosimetry systems took place in the SILENE reactor, in June 2002. Participants from 60 laboratories irradiated their dosemeters (physical and biological) using two different configurations of the reactor. In preparation for this intercomparison, the leakage radiation fields were characterised by spectrometry and dosimetry measurements using the ROSPEC spectrometer associated with a NE-213 scintillator, ionisation chambers, GM counters, diodes and thermoluminescence dosemeters (TLDs). For this intercomparison, a large area was required to irradiate the dosemeters both in free air and on phantoms. Therefore, measurements of the uniformity of the field were performed with activation detectors and TLDs for neutron and gammas, respectively. This paper describes the procedures used and the results obtained. PMID:15353691

  7. Development and evaluation of a technique for in vivo monitoring of 60Co in human lungs

    NASA Astrophysics Data System (ADS)

    de Mello, J. Q.; Lucena, E. A.; Dantas, A. L. A.; Dantas, B. M.

    2016-07-01

    60Co is a fission product of 235U and represents a risk of internal exposure of workers in nuclear power plants, especially those involved in the maintenance of potentially contaminated parts and equipment. The control of 60Co intake by inhalation can be performed through in vivo monitoring. This work describes the evaluation of a technique through the minimum detectable activity and the corresponding minimum detectable effective doses, based on biokinetic and dosimetric models of 60Co in the human body. The results allow to state that the technique is suitable either for monitoring of occupational exposures or evaluation of accidental intake.

  8. Biokinetics and internal dosimetry of inhaled metal tritide particles

    NASA Astrophysics Data System (ADS)

    Wang, Yansheng

    1998-12-01

    Metal tritides (MT), stable chemical compounds of tritium, are widely used in nuclear engineering facilities. MT particles can be released as aerosols. Inhaling MT particles is a potential occupational radiation hazard. Little information is available on their dissolution behavior, biokinetics, and dosimetry. The objectives of present dissertation are to estimate dissolution rates, to develop biokinetic models, to improve internal dosimetric considerations, and to classify MT materials. This study consisted of three phases: In vitro dissolution in a simulated lung fluid, In vivo rat experiments on retention and clearance, and biokinetic modeling and dosimetric evaluation. There was a supporting study on self- absorption of tritium beta in MT particles. MT materials used in this study were titanium (Ti) and zirconium (Zr) tritides. Results shows considerable self-absorption of beta particles and their energy, even for respirable MT particles smaller than 5 μm. The self-absorption factors should be required for counting MT particle samples and for estimating absorbed dose to tissues. In vitro and in vivo dissolution data indicate that Ti and Zr tritides are poorly soluble materials. Ti tritide belongs to the W class or M type while Zr tritide can be classified as Y class or S type. Due to long retention time of the MT particles, tritium betas directly from the particles contribute over 90% of the absorbed dose to lung. The lung dose contributes most of the effective dose to the whole body. Dissolved tritium including tritiated water (HTO) and organically bound tritium (OBT) has less effect on the lung dose and effective dose. Results on the annual limit on intake (ALI) indicate that the current radiation protection guideline based on HTO is not adequate for inhalation exposure to MT particles and needs to be modified. The biokinetic models developed in this study have predictive powers to estimate the consequences of a human inhalation exposure to MT aerosols. The

  9. International cooperative effort to establish dosimetry standardization for radiation processing

    SciTech Connect

    Farrar, H. IV

    1989-01-01

    Radiation processing is a rapidly developing technology with numerous applications in food treatment, sterilization, and polymer modification. The effectiveness of the process depends, however, on the proper application of dose and its measurement. These aspects are being considered by a wide group of experts from around the world who have joined together to write a comprehensive set of standards for dosimetry for radiation processing. Originally formed in 1984 to develop standards for food processing dosimetry, the group has now expanded into a full subcommittee of the American Society for Testing and Materials (ASTM), with 97 members from 19 countries. The scope of the standards now includes dosimetry for all forms of radiation processing. The group has now completed and published four standards, and is working on an additional seven. Three are specifically for food applications and the others are for all radiation applications, including food processing. Together, this set of standards will specify acceptable guidelines and methods for accomplishing the required irradiation treatment, and will be available for adoption by national regulatory agencies in their procedures and protocols. 1 tab.

  10. International Space Station: A testbed for experimental and computational dosimetry

    NASA Astrophysics Data System (ADS)

    Wilson, J.; Cucinotta, F.; Golightly, M.; Nealy, J.; Deangelis, G.; Anderson, B.; Clowdsley, M.; Luetke, N.; Zapp, N.; Shavers, M.

    The ISS and the prior station Mir provided the proving ground for future human long-duration space activity. A recent European Space Agency study recommended "Measurement campaigns on the ISS form the ideal tool for experimental validation of radiation environment models, of transport code algorithms and reaction cross sections". Indeed, prior measurements on Shuttle have provided vital information impacting both transport code and environmental model development. Recent studies using of the ISS 7A configuration with TLD area monitors demonstrated that computational dosimetry requires environmental models with accurate anisotropic and dynamic behavior, detailed information on rack loading, and an accurate 6 degree-of-freedom description of the ISS trajectory. The ISS model is now configured for 11A and uses an anisotropic and dynamic geomagnetic transmission and trapped proton models. The ISS 11A is instrumented with both passive and active dosimetric devices. Time resolved measurements have the advantage of isolating trapped proton and galactic cosmic ray components as was essential to transport code validation in Shuttle data analysis. ISS 11A model validation will begin with passive dosimetry as was used with ISS 7A. Directional dependent active measurements will play an important role in the validation of environmental model anisotropies.

  11. International space station: A testbed for experimental and computational dosimetry

    NASA Astrophysics Data System (ADS)

    Wilson, J. W.; Cucinotta, F. A.; Golightly, M. J.; Nealy, J. E.; Qualls, G. D.; Badavi, F. F.; De Angelis, G.; Anderson, B. M.; Clowdsley, M. S.; Luetke, N.; Zapp, N.; Shavers, M. R.; Semones, E.; Hunter, A.

    The ISS and the prior station Mir provided the proving ground for future human long-duration space activity. A recent European Space Agency study recommended "Measurement campaigns on the ISS form the ideal tool for experimental validation of radiation environment models, of transport code algorithms and reaction cross sections". Indeed, prior measurements on Shuttle have provided vital information impacting both transport code and environmental model development. Recent studies using the ISS 7A configuration with TLD area monitors demonstrated that computational dosimetry requires environmental models with accurate anisotropic and dynamic behavior, detailed information on rack loading, and an accurate 6 degree-of-freedom description of the ISS trajectory. The ISS model is now configured for 11A and uses an anisotropic and dynamic geomagnetic transmission and trapped proton models. The ISS 11A is instrumented with both passive and active dosimetric devices. Time resolved measurements have the advantage of isolating trapped proton and galactic cosmic ray components as was essential to transport code validation in Shuttle data analysis. ISS 11A model validation will begin with passive dosimetry as was used with ISS 7A. Directional dependent active measurements will play an important role in the validation of environmental model anisotropies.

  12. Development, validation, and implementation of a patient-specific Monte Carlo 3D internal dosimetry platform

    NASA Astrophysics Data System (ADS)

    Besemer, Abigail E.

    Targeted radionuclide therapy is emerging as an attractive treatment option for a broad spectrum of tumor types because it has the potential to simultaneously eradicate both the primary tumor site as well as the metastatic disease throughout the body. Patient-specific absorbed dose calculations for radionuclide therapies are important for reducing the risk of normal tissue complications and optimizing tumor response. However, the only FDA approved software for internal dosimetry calculates doses based on the MIRD methodology which estimates mean organ doses using activity-to-dose scaling factors tabulated from standard phantom geometries. Despite the improved dosimetric accuracy afforded by direct Monte Carlo dosimetry methods these methods are not widely used in routine clinical practice because of the complexity of implementation, lack of relevant standard protocols, and longer dose calculation times. The main goal of this work was to develop a Monte Carlo internal dosimetry platform in order to (1) calculate patient-specific voxelized dose distributions in a clinically feasible time frame, (2) examine and quantify the dosimetric impact of various parameters and methodologies used in 3D internal dosimetry methods, and (3) develop a multi-criteria treatment planning optimization framework for multi-radiopharmaceutical combination therapies. This platform utilizes serial PET/CT or SPECT/CT images to calculate voxelized 3D internal dose distributions with the Monte Carlo code Geant4. Dosimetry can be computed for any diagnostic or therapeutic radiopharmaceutical and for both pre-clinical and clinical applications. In this work, the platform's dosimetry calculations were successfully validated against previously published reference doses values calculated in standard phantoms for a variety of radionuclides, over a wide range of photon and electron energies, and for many different organs and tumor sizes. Retrospective dosimetry was also calculated for various pre

  13. An international dosimetry exchange for BNCT part II: computational dosimetry normalizations.

    PubMed

    Riley, K J; Binns, P J; Harling, O K; Albritton, J R; Kiger, W S; Rezaei, A; Sköld, K; Seppälä, T; Savolainen, S; Auterinen, I; Marek, M; Viererbl, L; Nievaart, V A; Moss, R L

    2008-12-01

    The meaningful sharing and combining of clinical results from different centers in the world performing boron neutron capture therapy (BNCT) requires improved precision in dose specification between programs. To this end absorbed dose normalizations were performed for the European clinical centers at the Joint Research Centre of the European Commission, Petten (The Netherlands), Nuclear Research Institute, Rez (Czech Republic), VTT, Espoo (Finland), and Studsvik, Nyköping (Sweden). Each European group prepared a treatment plan calculation that was bench-marked against Massachusetts Institute of Technology (MIT) dosimetry performed in a large, water-filled phantom to uniformly evaluate dose specifications with an estimated precision of +/-2%-3%. These normalizations were compared with those derived from an earlier exchange between Brookhaven National Laboratory (BNL) and MIT in the USA. Neglecting the uncertainties related to biological weighting factors, large variations between calculated and measured dose are apparent that depend upon the 10B uptake in tissue. Assuming a boron concentration of 15 microg g(-1) in normal tissue, differences in the evaluated maximum dose to brain for the same nominal specification of 10 Gy(w) at the different facilities range between 7.6 and 13.2 Gy(w) in the trials using boronophenylalanine (BPA) as the boron delivery compound and between 8.9 and 11.1 Gy(w) in the two boron sulfhydryl (BSH) studies. Most notably, the value for the same specified dose of 10 Gy(w) determined at the different participating centers using BPA is significantly higher than at BNL by 32% (MIT), 43% (VTT), 49% (JRC), and 74% (Studsvik). Conversion of dose specification is now possible between all active participants and should be incorporated into future multi-center patient analyses. PMID:19175101

  14. Modeling the imprecision in prospective dosimetry of internal exposure to uranium.

    PubMed

    Davesne, E; Chojnacki, E; Paquet, F; Blanchardon, E

    2009-02-01

    The dosimetry of internal exposure to radionuclides is performed on the basis of biokinetic and dosimetric models. For prospective purpose, the organ or effective dose resulting from potential conditions of exposure can be calculated by applying these models with dedicated software. However, it is acknowledged that a significant uncertainty is associated with such calculation due to the variability of individual cases and to the possible lack of knowledge about some factors influencing the dosimetry. This uncertainty has been studied in a range of situations by modeling the uncertainty on the model parameters by probability distributions and propagating this uncertainty onto the dose result by Monte Carlo calculation. However, while probability distributions are well adapted to model the known variability of a parameter, they may lead to an unrealistically low estimate of the uncertainty due to a lack of knowledge about some input parameters. Here we present a mathematical method, based on the Dempster-Shafer theory, to deal with such imprecise knowledge. We apply this method to the prospective dosimetry of inhaled uranium dust in the nuclear fuel cycle when its physico-chemical properties are not precisely known. The results show an increased estimation of the range of uncertainty as compared to the application of a probabilistic method. This Dempster-Shafer method may valuably be applied in future prospective dosimetry of internal exposure in order to more realistically estimate the uncertainty resulting from an imprecise knowledge of the parameters of the dose calculation. PMID:19131736

  15. PREFACE: 7th International Conference on 3D Radiation Dosimetry (IC3DDose)

    NASA Astrophysics Data System (ADS)

    Thwaites, David; Baldock, Clive

    2013-06-01

    IC3DDose 2013, the 7th International Conference on 3D Radiation Dosimetry held in Sydney, Australia from 4-8 November 2012, grew out of the DosGel series, which began as DosGel99, the 1st International Workshop on Radiation Therapy Gel Dosimetry in Lexington, Kentucky. Since 1999 subsequent DoSGel conferences were held in Brisbane, Australia (2001), Ghent, Belgium (2004), Sherbrooke, Canada (2006) and Crete, Greece (2008). In 2010 the conference was held on Hilton Head Island, South Carolina and underwent a name-change to IC3DDose. The aim of the first workshop was to bring together individuals, both researchers and users, with an interest in 3D radiation dosimetry techniques, with a mix of presentations from basic science to clinical applications, which has remained an objective for all of the meetings. One rationale of DosGel99 was stated as supporting the increasing clinical implementation of gel dosimetry, as the technique appeared, at that time, to be leaving the laboratories of gel dosimetry enthusiasts and entering clinical practice. Clearly by labelling the first workshop as the 1st, there was a vision of a continuing series, which has been fulfilled. On the other hand, the expectation of widespread clinical use of gel dosimetry has perhaps not been what was hoped for and anticipated. Nevertheless the rapidly increasing demand for advanced high-precision 3D radiotherapy technology and techniques has continued apace. The need for practical and accurate 3D dosimetry methods for development and quality assurance has only increased. By the 6th meeting, held in South Carolina in 2010, the Conference Scientific Committee recognised the wider developments in 3D systems and methods and decided to widen the scope, whilst keeping the same span from basic science to applications. This was signalled by a change of name from 'Dosgel' to 'IC3DDose', a name that has continued to this latest conference. The conference objectives were: to enhance the quality and accuracy of

  16. Internal in vitro dosimetry for fish using hydroxyapatite-based EPR detectors.

    PubMed

    Ivanov, D V; Shishkina, E A; Osipov, D I; Razumeev, R A; Pryakhin, E A

    2015-08-01

    A number of aquatic ecosystems were exposed to ionizing radiation as a result of the activities of the Mayak Production Association in the Southern Urals, former Soviet Union, in the 1950s. Currently, fishes inhabiting contaminated lakes are being actively studied. These investigations need dosimetric support. In the present paper the results of a pilot study for elaborating an EPR dosimeter which can be used for internal dosimetry in vitro are described. Biological hydroxyapatite is proposed here to be used as a detecting substance. More specifically, small hydroxyapatite grains are proposed for use as point detectors fixed in a solid matrix. After having been pelletized, the detectors were covered by Mylar and placed in the body of a fish to be stored in the fridge for several months. Application of the detectors for internal fish dosimetry demonstrated that the enamel sensitivity is sufficient for passive detection of ionizing radiation in fishes inhabiting contaminated lakes in the Southern Urals. PMID:25822591

  17. 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

  18. Development of a software tool for an internal dosimetry using MIRD method

    NASA Astrophysics Data System (ADS)

    Chaichana, A.; Tocharoenchai, C.

    2016-03-01

    Currently, many software packages for the internal radiation dosimetry have been developed. Many of them do not provide sufficient tools to perform all of the necessary steps from nuclear medicine image analysis for dose calculation. For this reason, we developed a CALRADDOSE software that can be performed internal dosimetry using MIRD method within a single environment. MATLAB software version 2015a was used as development tool. The calculation process of this software proceeds from collecting time-activity data from image data followed by residence time calculation and absorbed dose calculation using MIRD method. To evaluate the accuracy of this software, we calculate residence times and absorbed doses of 5 Ga- 67 studies and 5 I-131 MIBG studies and then compared the results with those obtained from OLINDA/EXM software. The results showed that the residence times and absorbed doses obtained from both software packages were not statistically significant differences. The CALRADDOSE software is a user-friendly, graphic user interface-based software for internal dosimetry. It provides fast and accurate results, which may be useful for a routine work.

  19. PREFACE: 8th International Conference on 3D Radiation Dosimetry (IC3DDose)

    NASA Astrophysics Data System (ADS)

    Olsson, Lars E.; Bäck, S.; Ceberg, Sofie

    2015-01-01

    IC3DDose 2014, the 8th International Conference on 3D Radiation Dosimetry was held in Ystad, Sweden, from 4-7 September 2014. This grew out of the DosGel series, which began as DosGel99, the 1st International Workshop on Radiation Therapy Gel Dosimetry in Lexington, Kentucky. Since 1999 subsequent DoSGel conferences were held in Brisbane, Australia (2001), Ghent, Belgium (2004), Sherbrooke, Canada (2006) and Crete, Greece (2008). In 2010 the conference was held on Hilton Head Island, South Carolina and underwent a name-change to IC3DDose. The 7th and last meeting was held in Sydney, Australia from 4-8 November 2012. It is worth remembering that the conference series started at the very beginning of the intensity modulated radiotherapy era and that the dosimeters being developed then were, to some extent, ahead of the clinical need of radiotherapy. However, since then the technical developments in radiation therapy have been dramatic, with dynamic treatments, including tracking, gating and volumetric modulated arc therapy, widely introduced in the clinic with the need for 3D dosimetry thus endless. This was also reflected by the contributions at the meeting in Ystad. Accordingly the scope of the meeting has also broadened to IC3DDOSE - I See Three-Dimensional Dose. A multitude of dosimetry techniques and radiation detectors are now represented, all with the common denominator: three-dimensional or 3D. Additionally, quality assurance (QA) procedures and other aspects of clinical dosimetry are represented. The implementation of new dosimetric techniques in radiotherapy is a process that needs every kind of caution, carefulness and thorough validation. Therefore, the clinical needs, reformulated as the aims for IC3DDOSE - I See Three-Dimensional Dose, are: • Enhance the quality and accuracy of radiation therapy treatments through improved clinical dosimetry. • Investigate and understand the dosimetric challenges of modern radiation treatment techniques. • Provide

  20. PREFACE: The 5th International Conference on Radiotherapy Gel Dosimetry (DOSGEL 2008)

    NASA Astrophysics Data System (ADS)

    Maris, Thomas G.; Pappas, Evangelos

    2009-07-01

    The International Conference on Radiotherapy Gel Dosimetry (DOSGEL) is held every two years. Its purpose is to bring together basic science and clinical researchers, medical physicists and clinicians from around the world to discuss the state-of-the-art of the gel dosimetry technique and to set the directions and trends for its future improvements. Gel dosimetry can be broadly defined as using a gel that can react to the absorption of ionizing radiation, and that can retain this information which can subsequently be retrieved by an external imaging modality. Examples of radiation-sensitive gels include, but are not limited to, polymer gel dosimeters, Fricke gel dosimeters and others. Imaging modalities that are of general use in this field are (in alphabetical order) magnetic resonance imaging (MRI), optical light computed tomography and x-ray computed tomography. This volume comprises the proceedings of the 5th International Conference on Radiotherapy Gel Dosimetry (DOSGEL 2008). The conference, organised by the University of Crete, Medical Physics Department, took place in Hersonissos, Crete, Greece from 29 September to 3 October 2008. The meeting aimed to continue the series of biannual DOSGEL conferences and focused on the promotion of gel dosimetry techniques by setting the trends for their future improvements. The main scientific session topics of DOSGEL 2008 were the following: Chemistry and fundamental properties of polymer gel dosimeters Gel dosimetry with Optical Computed Tomography Gel dosimetry with Magnetic Resonance Imaging Gel dosimetry with other than Optical CT and MR scan Techniques Other 3D dosimeters Gel dosimetry applications Local Organizing Committee Thomas G Maris (University of Crete, Greece, Chairman DOSGEL 2008) John Damilakis (University of Crete, Greece) Evangelos Pappas (University of Crete, Greece) Antonios Papadakis (University of Crete, Greece) Fotini Zacharopoulou (University of Crete, Greece) John Stratakis (University of Crete

  1. Monte Carlo and experimental internal radionuclide dosimetry in RANDO head phantom.

    PubMed

    Ghahraman Asl, Ruhollah; Nasseri, Shahrokh; Parach, Ali Asghar; Zakavi, Seyed Rasoul; Momennezhad, Mehdi; Davenport, David

    2015-09-01

    Monte Carlo techniques are widely employed in internal dosimetry to obtain better estimates of absorbed dose distributions from irradiation sources in medicine. Accurate 3D absorbed dosimetry would be useful for risk assessment of inducing deterministic and stochastic biological effects for both therapeutic and diagnostic radiopharmaceuticals in nuclear medicine. The goal of this study was to experimentally evaluate the use of Geant4 application for tomographic emission (GATE) Monte Carlo package for 3D internal dosimetry using the head portion of the RANDO phantom. GATE package (version 6.1) was used to create a voxel model of a human head phantom from computed tomography (CT) images. Matrix dimensions consisted of 319 × 216 × 30 voxels (0.7871 × 0.7871 × 5 mm(3)). Measurements were made using thermoluminescent dosimeters (TLD-100). One rod-shaped source with 94 MBq activity of (99m)Tc was positioned in the brain tissue of the posterior part of the human head phantom in slice number 2. The results of the simulation were compared with measured mean absorbed dose per cumulative activity (S value). Absorbed dose was also calculated for each slice of the digital model of the head phantom and dose volume histograms (DVHs) were computed to analyze the absolute and relative doses in each slice from the simulation data. The S-values calculated by GATE and TLD methods showed a significant correlation (correlation coefficient, r(2) ≥ 0.99, p < 0.05) with each other. The maximum relative percentage differences were ≤14% for most cases. DVHs demonstrated dose decrease along the direction of movement toward the lower slices of the head phantom. Based on the results obtained from GATE Monte Carlopackage it can be deduced that a complete dosimetry simulation study, from imaging to absorbed dose map calculation, is possible to execute in a single framework. PMID:26232251

  2. 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.

  3. An international dosimetry exchange for boron neutron capture therapy, Part I: Absorbed dose measurements

    SciTech Connect

    Binns, P.J.; Riley, K.J.; Harling, O.K.

    2005-12-15

    An international collaboration was organized to undertake a dosimetry exchange to enable the future combination of clinical data from different centers conducting neutron capture therapy trials. As a first step (Part I) the dosimetry group from the Americas, represented by MIT, visited the clinical centers at Studsvik (Sweden), VTT Espoo (Finland), and the Nuclear Research Institute (NRI) at Rez (Czech Republic). A combined VTT/NRI group reciprocated with a visit to MIT. Each participant performed a series of dosimetry measurements under equivalent irradiation conditions using methods appropriate to their clinical protocols. This entailed in-air measurements and dose versus depth measurements in a large water phantom. Thermal neutron flux as well as fast neutron and photon absorbed dose rates were measured. Satisfactory agreement in determining absorbed dose within the experimental uncertainties was obtained between the different groups although the measurement uncertainties are large, ranging between 3% and 30% depending upon the dose component and the depth of measurement. To improve the precision in the specification of absorbed dose amongst the participants, the individually measured dose components were normalized to the results from a single method. Assuming a boron concentration of 15 {mu}g g{sup -1} that is typical of concentrations realized clinically with the boron delivery compound boronophenylalanine-fructose, systematic discrepancies in the specification of the total biologically weighted dose of up to 10% were apparent between the different groups. The results from these measurements will be used in future to normalize treatment plan calculations between the different clinical dosimetry protocols as Part II of this study.

  4. An international dosimetry exchange for boron neutron capture therapy. Part I: Absorbed dose measurements.

    PubMed

    Binns, P J; Riley, K J; Harling, O K; Kiger, W S; Munck af Rosenschöld, P M; Giusti, V; Capala, J; Sköld, K; Auterinen, I; Serén, T; Kotiluoto, P; Uusi-Simola, J; Marek, M; Viererbl, L; Spurny, F

    2005-12-01

    An international collaboration was organized to undertake a dosimetry exchange to enable the future combination of clinical data from different centers conducting neutron capture therapy trials. As a first step (Part I) the dosimetry group from the Americas, represented by MIT, visited the clinical centers at Studsvik (Sweden), VTT Espoo (Finland), and the Nuclear Research Institute (NRI) at Rez (Czech Republic). A combined VTT/NRI group reciprocated with a visit to MIT. Each participant performed a series of dosimetry measurements under equivalent irradiation conditions using methods appropriate to their clinical protocols. This entailed in-air measurements and dose versus depth measurements in a large water phantom. Thermal neutron flux as well as fast neutron and photon absorbed dose rates were measured. Satisfactory agreement in determining absorbed dose within the experimental uncertainties was obtained between the different groups although the measurement uncertainties are large, ranging between 3% and 30% depending upon the dose component and the depth of measurement. To improve the precision in the specification of absorbed dose amongst the participants, the individually measured dose components were normalized to the results from a single method. Assuming a boron concentration of 15 microg g(-1) that is typical of concentrations realized clinically with the boron delivery compound boronophenylalanine-fructose, systematic discrepancies in the specification of the total biologically weighted dose of up to 10% were apparent between the different groups. The results from these measurements will be used in future to normalize treatment plan calculations between the different clinical dosimetry protocols as Part II of this study. PMID:16475772

  5. Items Supporting the Hanford Internal Dosimetry Program Implementation of the IMBA Computer Code

    SciTech Connect

    Carbaugh, Eugene H.; Bihl, Donald E.

    2008-01-07

    The Hanford Internal Dosimetry Program has adopted the computer code IMBA (Integrated Modules for Bioassay Analysis) as its primary code for bioassay data evaluation and dose assessment using methodologies of ICRP Publications 60, 66, 67, 68, and 78. The adoption of this code was part of the implementation plan for the June 8, 2007 amendments to 10 CFR 835. This information release includes action items unique to IMBA that were required by PNNL quality assurance standards for implementation of safety software. Copie of the IMBA software verification test plan and the outline of the briefing given to new users are also included.

  6. Probabilistic accident consequence uncertainty analysis -- Uncertainty assessment for internal dosimetry. Volume 2: Appendices

    SciTech Connect

    Goossens, L.H.J.; Kraan, B.C.P.; Cooke, R.M.; Harrison, J.D.; Harper, F.T.; Hora, S.C.

    1998-04-01

    The development of two new probabilistic accident consequence codes, MACCS and COSYMA, was completed in 1990. These codes estimate the consequence from the accidental releases of radiological material from hypothesized accidents at nuclear installations. In 1991, the US Nuclear Regulatory Commission and the Commission of the European Communities began cosponsoring a joint uncertainty analysis of the two codes. The ultimate objective of this joint effort was to systematically develop credible and traceable uncertainty distributions for the respective code input variables. A formal expert judgment elicitation and evaluation process was identified as the best technology available for developing a library of uncertainty distributions for these consequence parameters. This report focuses on the results of the study to develop distribution for variables related to the MACCS and COSYMA internal dosimetry models. This volume contains appendices that include (1) a summary of the MACCS and COSYMA consequence codes, (2) the elicitation questionnaires and case structures, (3) the rationales and results for the panel on internal dosimetry, (4) short biographies of the experts, and (5) the aggregated results of their responses.

  7. Comparative analysis of 60Co intensity-modulated radiation therapy.

    PubMed

    Fox, Christopher; Romeijn, H Edwin; Lynch, Bart; Men, Chunhua; Aleman, Dionne M; Dempsey, James F

    2008-06-21

    In this study, we perform a scientific comparative analysis of using (60)Co beams in intensity-modulated radiation therapy (IMRT). In particular, we evaluate the treatment plan quality obtained with (i) 6 MV, 18 MV and (60)Co IMRT; (ii) different numbers of static multileaf collimator (MLC) delivered (60)Co beams and (iii) a helical tomotherapy (60)Co beam geometry. We employ a convex fluence map optimization (FMO) model, which allows for the comparison of plan quality between different beam energies and configurations for a given case. A total of 25 clinical patient cases that each contain volumetric CT studies, primary and secondary delineated targets, and contoured structures were studied: 5 head-and-neck (H&N), 5 prostate, 5 central nervous system (CNS), 5 breast and 5 lung cases. The DICOM plan data were anonymized and exported to the University of Florida optimized radiation therapy (UFORT) treatment planning system. The FMO problem was solved for each case for 5-71 equidistant beams as well as a helical geometry for H&N, prostate, CNS and lung cases, and for 3-7 equidistant beams in the upper hemisphere for breast cases, all with 6 MV, 18 MV and (60)Co dose models. In all cases, 95% of the target volumes received at least the prescribed dose with clinical sparing criteria for critical organs being met for all structures that were not wholly or partially contained within the target volume. Improvements in critical organ sparing were found with an increasing number of equidistant (60)Co beams, yet were marginal above 9 beams for H&N, prostate, CNS and lung. Breast cases produced similar plans for 3-7 beams. A helical (60)Co beam geometry achieved similar plan quality as static plans with 11 equidistant (60)Co beams. Furthermore, 18 MV plans were initially found not to provide the same target coverage as 6 MV and (60)Co plans; however, adjusting the trade-offs in the optimization model allowed equivalent target coverage for 18 MV. For plans with comparable

  8. Comparative analysis of 60Co intensity-modulated radiation therapy

    NASA Astrophysics Data System (ADS)

    Fox, Christopher; Romeijn, H. Edwin; Lynch, Bart; Men, Chunhua; Aleman, Dionne M.; Dempsey, James F.

    2008-06-01

    In this study, we perform a scientific comparative analysis of using 60Co beams in intensity-modulated radiation therapy (IMRT). In particular, we evaluate the treatment plan quality obtained with (i) 6 MV, 18 MV and 60Co IMRT; (ii) different numbers of static multileaf collimator (MLC) delivered 60Co beams and (iii) a helical tomotherapy 60Co beam geometry. We employ a convex fluence map optimization (FMO) model, which allows for the comparison of plan quality between different beam energies and configurations for a given case. A total of 25 clinical patient cases that each contain volumetric CT studies, primary and secondary delineated targets, and contoured structures were studied: 5 head-and-neck (H&N), 5 prostate, 5 central nervous system (CNS), 5 breast and 5 lung cases. The DICOM plan data were anonymized and exported to the University of Florida optimized radiation therapy (UFORT) treatment planning system. The FMO problem was solved for each case for 5-71 equidistant beams as well as a helical geometry for H&N, prostate, CNS and lung cases, and for 3-7 equidistant beams in the upper hemisphere for breast cases, all with 6 MV, 18 MV and 60Co dose models. In all cases, 95% of the target volumes received at least the prescribed dose with clinical sparing criteria for critical organs being met for all structures that were not wholly or partially contained within the target volume. Improvements in critical organ sparing were found with an increasing number of equidistant 60Co beams, yet were marginal above 9 beams for H&N, prostate, CNS and lung. Breast cases produced similar plans for 3-7 beams. A helical 60Co beam geometry achieved similar plan quality as static plans with 11 equidistant 60Co beams. Furthermore, 18 MV plans were initially found not to provide the same target coverage as 6 MV and 60Co plans; however, adjusting the trade-offs in the optimization model allowed equivalent target coverage for 18 MV. For plans with comparable target coverage

  9. Low-frequency electrical dosimetry: research agenda of the IEEE International Committee on Electromagnetic Safety.

    PubMed

    Reilly, J Patrick; Hirata, Akimasa

    2016-06-21

    This article treats unsettled issues in the use of numerical models of electrical dosimetry as applied to international limits on human exposure to low-frequency (typically  <  100 kHz) electromagnetic fields and contact current. The perspective in this publication is that of Subcommittee 6 of IEEE-ICES (International Committee on Electromagnetic Safety) Technical Committee 95. The paper discusses 25 issues needing attention, fitting into three general categories: induction models; electrostimulation models; and human exposure limits. Of these, 9 were voted as 'high priority' by members of Subcommittee 6. The list is presented as a research agenda for refinements in numerical modeling with applications to human exposure limits. It is likely that such issues are also important in medical and electrical product safety design applications. PMID:27223463

  10. Low-frequency electrical dosimetry: research agenda of the IEEE International Committee on Electromagnetic Safety

    NASA Astrophysics Data System (ADS)

    Reilly, J. Patrick; Hirata, Akimasa

    2016-06-01

    This article treats unsettled issues in the use of numerical models of electrical dosimetry as applied to international limits on human exposure to low-frequency (typically  <  100 kHz) electromagnetic fields and contact current. The perspective in this publication is that of Subcommittee 6 of IEEE-ICES (International Committee on Electromagnetic Safety) Technical Committee 95. The paper discusses 25 issues needing attention, fitting into three general categories: induction models; electrostimulation models; and human exposure limits. Of these, 9 were voted as ‘high priority’ by members of Subcommittee 6. The list is presented as a research agenda for refinements in numerical modeling with applications to human exposure limits. It is likely that such issues are also important in medical and electrical product safety design applications.

  11. Measurements of (60)Co in massive steel samples exposed to the Hiroshima atomic bomb explosion.

    PubMed

    Gasparro, Joël; Hult, Mikael; Marissens, Gerd; Hoshi, Masaharu; Tanaka, Kenichi; Endo, Satoru; Laubenstein, Matthias; Dombrowski, Harald; Arnold, Dirk

    2012-04-01

    To study discrepancies in retrospective Hiroshima dosimetry, the specific activity of (60)Co in 16 steel samples from Hiroshima was measured using gamma-ray spectrometry in underground laboratories. There is general agreement between these new activity measurements and the specific activities derived from previously calculated dose values on the one hand and former measurements of samples gathered at distances less than 1,000 m from the center of the explosion (< 1,000 m slant range) on the other. It was found that activities at long range (> 1,300 m slant range) were mainly cosmogenically induced. Furthermore, at long range, these results are in disagreement with older measurements whose specific activity values were 10 to 100 times higher than predicted by computer model calculations in DS86 and DS02. As a consequence, the previously reported discrepancy is not confirmed. PMID:22378201

  12. Nuclear Decay Data for the International Reactor Dosimetry Library for Fission and Fusion (IRDFF): Updated Evaluations of the Half-Lives and Gamma Ray Intensities

    NASA Astrophysics Data System (ADS)

    Chechev, Valery P.; Kuzmenko, Nikolay K.

    2016-02-01

    Updated evaluations of the half-lives and prominent gamma ray intensities have been presented for 20 radionuclides - dosimetry reaction residuals. The new values of these decay characteristics recommended for the IRDFF library were obtained using the approaches and methodology adopted by the working group of the Decay Data Evaluation Project (DDEP) cooperation. The experimental data published up to 2014 were taken into account in updated evaluations. The list of radionuclides includes 3H, 18F, 22Na, 24Na, 46Sc, 51Cr, 54Mn, 59Fe, 57Co, 60Co, 57Ni, 64Cu, 88Y, 132Te, 131I, 140Ba, 140La, 141Ce, 182Ta, 198Au.

  13. Identification of 63Ni and 60Co produced in a steel sample by thermal neutrons from the Hiroshima atomic bomb

    NASA Astrophysics Data System (ADS)

    Shizuma, K.; Iwatani, K.; Hasai, H.; Oka, T.; Hoshi, M.; Shibata, S.; Imamura, M.; Shibata, T.

    1997-02-01

    Long-lived residual radioactivity 63Ni produced by the (n, γ) reaction was detected for the first time from a steel plate sampled at near the hypocenter of the Hiroshima atomic bomb. Nickel and cobalt were chemically separated and enriched from the steel sample. Low energy beta rays of 63Ni were measured with a low-background liquid scintillation counter and gamma-rays of 60Co were measured with a low background Ge detector. Specific activities were determined as 0.0063±0.0004 Bq mg -1 for {63Ni}/{Ni} and 8.70±0.46 Bq mg -1 for {60Co}/{Co} at the time of the bomb explosion. Comparisons with the calculated yield based on the current dosimetry system DS86 neutrons were also given.

  14. 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.

  15. Probabilistic accident consequence uncertainty analysis -- Uncertainty assessment for internal dosimetry. Volume 1: Main report

    SciTech Connect

    Goossens, L.H.J.; Kraan, B.C.P.; Cooke, R.M.; Harrison, J.D.; Harper, F.T.; Hora, S.C.

    1998-04-01

    The development of two new probabilistic accident consequence codes, MACCS and COSYMA, was completed in 1990. These codes estimate the consequence from the accidental releases of radiological material from hypothesized accidents at nuclear installations. In 1991, the US Nuclear Regulatory Commission and the Commission of the European Communities began cosponsoring a joint uncertainty analysis of the two codes. The ultimate objective of this joint effort was to systematically develop credible and traceable uncertainty distributions for the respective code input variables. A formal expert judgment elicitation and evaluation process was identified as the best technology available for developing a library of uncertainty distributions for these consequence parameters. This report focuses on the results of the study to develop distribution for variables related to the MACCS and COSYMA internal dosimetry models.

  16. Radiolytic degradation scheme for 60Co-irradiated corticosteroids

    SciTech Connect

    Kane, M.P.; Tsuji, K.

    1983-01-01

    The cobalt 60 radiolytic degradation products have been identified in the following corticosteroids: cortisone, cortisone acetate, hydrocortisone, hydrocortisone acetate, hydrocortisone sodium succinate, isoflupredone acetate, methylprednisolone, methylprednisolone acetate, prednisolone, prednisolone acetate, and prednisone. Two major types of degradation processes have been identified: loss of the corticoid side chain on the D-ring to produce the C-17 ketone and conversion of the C-11 alcohol, if present, to the C-11 ketone. Minor degradation products derived from other changes affecting the side chain are also identified in several corticosteroids. These compounds are frequently associated in corticosteroids as process impurities or degradation compounds. No new radiolytic compounds unique to 60Co-irradiation have been found. The majority of corticosteroids have been shown to be stable to 60Co-irradiation. The rates of radiolytic degradation ranged from 0.2 to 1.4%/Mrad.

  17. Technical basis for the internal dosimetry program at the Y-12 Plant

    SciTech Connect

    Ashley, J.C.; Barber, J.M.; Snapp, L.M.; Turner, J.E.

    1992-03-02

    Since the beginning of plant operations. almost all work with radioactive materials has involved isotopes associated with uranium, enriched or depleted in U[sup 235]. While limited quantities of isotopes of elements other than uranium are present, workplace monitoring and precess knowledge have established that internal exposure from these other isotopes is insignificant in comparison with uranium. While the changing plant mission may necessitate the consideration of internal exposure from other isotopes at some point in time, only enriched and depleted uranium will be considered in this basis document. The portions of the internal dosimetry technical basis which may be unique to the Y-12 Plant is considered in this manual. This manual presents the technical basis of the routine in vivo and in vitro bioassay programs including choice of frequency, participant selection criteria, and action level guidelines. Protocols for special bioassay will be presented in the chapters which described the basis for intake, uptake, and dam assessment. A discussion of the factors which led to the need to develop a special biokinetic model for uranium at the Y-12 Plant, as well as a description of the model's basic parameters, are included in this document.

  18. Comparison of PBTK model and biomarker based estimates of the internal dosimetry of acrylamide.

    PubMed

    DeWoskin, R S; Sweeney, L M; Teeguarden, J G; Sams, R; Vandenberg, J

    2013-08-01

    Estimates of internal dosimetry for acrylamide (AA, 2-propenamide; CASRN: 79-06-1) and its active metabolite glycidamide (GA) were compared using either biomarkers of internal exposure (hemoglobin adduct levels in rats and humans) or a PBTK model (Sweeney et al., 2010). The resulting impact on the human equivalent dose (HED, oral exposures), the human equivalent concentration (HEC, inhalation), and final reference values was also evaluated. Both approaches yielded similar AA HEDs and HECs for the most sensitive noncancer effect of neurotoxicity, identical oral reference doses (RfD) of 2×10(-3) mg AA/kg bw/d, and nearly identical inhalation reference concentrations (RfC=0.006 mg/m(3) and 0.007 mg/m(3), biomarker and PBTK results, respectively). HED and HEC values for carcinogenic potential were very similar, resulting in identical inhalation unit risks of 0.1/(mg AA/m(3)), and nearly identical oral cancer slope factors (0.4 and 0.5/mg AA/kg bw/d), biomarker and PBTK results, respectively. The concordance in estimated HEDs, HECs, and reference values from these two diverse methods increases confidence in those values. Advantages and specific application of each approach are discussed. (Note: Reference values derived with the PBPK model were part of this research, and do not replace values currently posted on IRIS: http://www.epa.gov/iris/toxreviews/0286tr.pdf.). PMID:23707562

  19. A standard Fricke dosimeter compared to an ionization chamber used for dosimetric characterization of 60Co photon beam

    NASA Astrophysics Data System (ADS)

    Moussous, Ouiza; Medjadj, Toufik

    2016-06-01

    The main objective of this study was to investigate the Fricke dosimeter water equivalent system for measurement of dosimetric parameters for photon beam. The parameters measured with the Fricke dosimeter were compared to those obtained with an ionization chamber. In this work characteristics for 60Co γ-rays of field sizes ranging from 5 × 5 cm2 to 20 × 20 cm2 are reported. The measurements were carried out in the secondary standard dosimetry laboratory using a collimated 60Co gamma source therapy unit. The 60Co beam output in terms of absorbed dose to water was obtained as per IAEA TRS 398 recommendations using cylindrical ionization chamber, whose ND,w has been supplied by the IAEA's reference laboratory. Specific quantities measured include: output factors, peak scatter factor, lateral beam profiles and percentage depth dose. The Fricke dosimeters were irradiated in a water phantom using the suitable poly (methyl methacrylate), PMMA stand. Our results demonstrate that Fricke dosimeter and ionization chamber agree with each other.

  20. Development of a 9-months pregnant hybrid phantom and its internal dosimetry for thyroid agents.

    PubMed

    Hoseinian-Azghadi, E; Rafat-Motavalli, L; Miri-Hakimabad, H

    2014-07-01

    As a consequence of fetal radiosensitivity, the estimation of internal dose received by a fetus from radiopharmaceuticals applied to the mother is often important in nuclear medicine. A new 9-months pregnant phantom based on magnetic resonance (MR) images tied to the International Commission on Radiological Protection (ICRP) reference voxel phantom has been developed. Maternal and fetal organs were segmented from a set of pelvic MR images of a 9-months pregnant subject using 3D-DOCTOR(TM) and then imported into the 3D modeling software package Rhinoceros(TM) for combining with the adult female ICRP voxel phantom and further modeling. Next, the phantom organs were rescaled to match with reference masses described in ICRP Publications. The internal anatomy of previous pregnant phantom models had been limited to the fetal brain and skeleton only, but the fetus model developed in this study incorporates 20 different organs. The current reference phantom has been developed for application in comprehensive dosimetric study in nuclear medicine. The internal dosimetry calculations were performed for thyroid agents using the Monte Carlo transport method. Biokinetic data for these radiopharmaceuticals were used to estimate cumulated activity during pregnancy and maternal and fetal organ doses at seven different maximum thyroid uptake levels. Calculating the dose distribution was also presented in a sagittal view of the pregnant model utilizing the mesh tally function. The comparisons showed, in general, an overestimation of the absorbed dose to the fetus and an underestimation of the fetal thyroid dose in previous studies compared with the values based on the current hybrid phantom. PMID:24515254

  1. Development of a 9-months pregnant hybrid phantom and its internal dosimetry for thyroid agents

    PubMed Central

    Hoseinian-Azghadi, E.; Rafat-Motavalli, L.; Miri-Hakimabad, H.

    2014-01-01

    As a consequence of fetal radiosensitivity, the estimation of internal dose received by a fetus from radiopharmaceuticals applied to the mother is often important in nuclear medicine. A new 9-months pregnant phantom based on magnetic resonance (MR) images tied to the International Commission on Radiological Protection (ICRP) reference voxel phantom has been developed. Maternal and fetal organs were segmented from a set of pelvic MR images of a 9-months pregnant subject using 3D-DOCTORTM and then imported into the 3D modeling software package RhinocerosTM for combining with the adult female ICRP voxel phantom and further modeling. Next, the phantom organs were rescaled to match with reference masses described in ICRP Publications. The internal anatomy of previous pregnant phantom models had been limited to the fetal brain and skeleton only, but the fetus model developed in this study incorporates 20 different organs. The current reference phantom has been developed for application in comprehensive dosimetric study in nuclear medicine. The internal dosimetry calculations were performed for thyroid agents using the Monte Carlo transport method. Biokinetic data for these radiopharmaceuticals were used to estimate cumulated activity during pregnancy and maternal and fetal organ doses at seven different maximum thyroid uptake levels. Calculating the dose distribution was also presented in a sagittal view of the pregnant model utilizing the mesh tally function. The comparisons showed, in general, an overestimation of the absorbed dose to the fetus and an underestimation of the fetal thyroid dose in previous studies compared with the values based on the current hybrid phantom. PMID:24515254

  2. Development of derived investigation levels for use in internal dosimetry at the West Valley Demonstration Project

    SciTech Connect

    Johnson, P.

    1991-12-31

    The objective was to determine if the routine intemal dosimetry program at the West Valley Demonstration Project is capable of meeting the performance objective of 1 mSv annual effective dose equivalent due to internal contamination. With the use of the computer code REMedy the annual effective dose equivalent is calculated. Some of the radionuclides of concern result in an annual effective dose equivalent that exceeds the performance objective. Although the results exceed the performance objective, in all but two cases they do not exceed the US DOE regulatory limits. In these instances the Th-232 and Am-241 were determined to exceed the committed dose equivalent limit to their limiting tissue. In order to document the potential missed dose for regulatory compliance, Sr-90 is used as an indicator for Th-232. For Am-241 an investigation as to whether or not the minimum detectable amount can be lowered is performed. The derived investigation levels as a result of this project are 4.9E3 Bq/lung count for Co-60, 2.2E4 Bq/lung count for Cs-137, 1.9 Bq/1 for Sr-90 and for radionuclides other than Sr-90 any value greater than or equal to three standard deviations above their net count is considered to require further investigation.

  3. Internal photon and electron dosimetry of the newborn patient—a hybrid computational phantom study

    NASA Astrophysics Data System (ADS)

    Wayson, Michael; Lee, Choonsik; Sgouros, George; Treves, S. Ted; Frey, Eric; Bolch, Wesley E.

    2012-03-01

    Estimates of radiation absorbed dose to organs of the nuclear medicine patient are a requirement for administered activity optimization and for stochastic risk assessment. Pediatric patients, and in particular the newborn child, represent that portion of the patient population where such optimization studies are most crucial owing to the enhanced tissue radiosensitivities and longer life expectancies of this patient subpopulation. In cases where whole-body CT imaging is not available, phantom-based calculations of radionuclide S values—absorbed dose to a target tissue per nuclear transformation in a source tissue—are required for dose and risk evaluation. In this study, a comprehensive model of electron and photon dosimetry of the reference newborn child is presented based on a high-resolution hybrid-voxel phantom from the University of Florida (UF) patient model series. Values of photon specific absorbed fraction (SAF) were assembled for both the reference male and female newborn using the radiation transport code MCNPX v2.6. Values of electron SAF were assembled in a unique and time-efficient manner whereby the collisional and radiative components of organ dose--for both self- and cross-dose terms—were computed separately. Dose to the newborn skeletal tissues were assessed via fluence-to-dose response functions reported for the first time in this study. Values of photon and electron SAFs were used to assemble a complete set of S values for some 16 radionuclides commonly associated with molecular imaging of the newborn. These values were then compared to those available in the OLINDA/EXM software. S value ratios for organ self-dose ranged from 0.46 to 1.42, while similar ratios for organ cross-dose varied from a low of 0.04 to a high of 3.49. These large discrepancies are due in large part to the simplistic organ modeling in the stylized newborn model used in the OLINDA/EXM software. A comprehensive model of internal dosimetry is presented in this study for

  4. Internal Photon and Electron Dosimetry of the Newborn Patient – A Hybrid Computational Phantom Study

    PubMed Central

    Wayson, Michael; Lee, Choonsik; Sgouros, George; Treves, S. Ted; Frey, Eric; Bolch, Wesley E.

    2013-01-01

    /EXM software. Conclusion A comprehensive model of internal dosimetry is presented in this study for the newborn nuclear medicine patient based upon the UF hybrid computational phantom. Photon dose-response functions, photon and electron specific absorbed fractions, and tables of radionuclide S values for the newborn child – both male and female – are given in a series of four electronic annexes. These values can be applied to optimization studies of image quality and stochastic risk for this most vulnerable class of pediatric patients. PMID:22354044

  5. MIRD Pamphlet No. 23: Quantitative SPECT for Patient-Specific 3-Dimensional Dosimetry in Internal Radionuclide Therapy

    PubMed Central

    Dewaraja, Yuni K.; Frey, Eric C.; Sgouros, George; Brill, A. Bertrand; Roberson, Peter; Zanzonico, Pat B.; Ljungberg, Michael

    2012-01-01

    In internal radionuclide therapy, a growing interest in voxel-level estimates of tissue-absorbed dose has been driven by the desire to report radiobiologic quantities that account for the biologic consequences of both spatial and temporal nonuniformities in these dose estimates. This report presents an overview of 3-dimensional SPECT methods and requirements for internal dosimetry at both regional and voxel levels. Combined SPECT/CT image-based methods are emphasized, because the CT-derived anatomic information allows one to address multiple technical factors that affect SPECT quantification while facilitating the patient-specific voxel-level dosimetry calculation itself. SPECT imaging and reconstruction techniques for quantification in radionuclide therapy are not necessarily the same as those designed to optimize diagnostic imaging quality. The current overview is intended as an introduction to an upcoming series of MIRD pamphlets with detailed radionuclide-specific recommendations intended to provide best-practice SPECT quantification–based guidance for radionuclide dosimetry. PMID:22743252

  6. Three-Dimensional Radiobiologic Dosimetry: Application of Radiobiologic Modeling to Patient-Specific 3-Dimensional Imaging–Based Internal Dosimetry

    PubMed Central

    Prideaux, Andrew R.; Song, Hong; Hobbs, Robert F.; He, Bin; Frey, Eric C.; Ladenson, Paul W.; Wahl, Richard L.; Sgouros, George

    2010-01-01

    Phantom-based and patient-specific imaging-based dosimetry methodologies have traditionally yielded mean organ-absorbed doses or spatial dose distributions over tumors and normal organs. In this work, radiobiologic modeling is introduced to convert the spatial distribution of absorbed dose into biologically effective dose and equivalent uniform dose parameters. The methodology is illustrated using data from a thyroid cancer patient treated with radioiodine. Methods Three registered SPECT/CT scans were used to generate 3-dimensional images of radionuclide kinetics (clearance rate) and cumulated activity. The cumulated activity image and corresponding CT scan were provided as input into an EGSnrc-based Monte Carlo calculation: The cumulated activity image was used to define the distribution of decays, and an attenuation image derived from CT was used to define the corresponding spatial tissue density and composition distribution. The rate images were used to convert the spatial absorbed dose distribution to a biologically effective dose distribution, which was then used to estimate a single equivalent uniform dose for segmented volumes of interest. Equivalent uniform dose was also calculated from the absorbed dose distribution directly. Results We validate the method using simple models; compare the dose-volume histogram with a previously analyzed clinical case; and give the mean absorbed dose, mean biologically effective dose, and equivalent uniform dose for an illustrative case of a pediatric thyroid cancer patient with diffuse lung metastases. The mean absorbed dose, mean biologically effective dose, and equivalent uniform dose for the tumor were 57.7, 58.5, and 25.0 Gy, respectively. Corresponding values for normal lung tissue were 9.5, 9.8, and 8.3 Gy, respectively. Conclusion The analysis demonstrates the impact of radiobiologic modeling on response prediction. The 57% reduction in the equivalent dose value for the tumor reflects a high level of dose

  7. Fieldbus: technology application in a 60Co sterilization plant

    NASA Astrophysics Data System (ADS)

    Karam, D.; Sampa, M. H. O.; Rela, P. R.

    2000-03-01

    Process instrumentation was made by pressure signals in the 1940s. In the 1960s, 4-20 mA analogue signals were introduced. The development of digital processors in the 1970s sparked the use of computers to monitor and control instruments from a central point. In the 1980s smart sensors were developed and implemented in digital control, microprocessor environments. Fieldbus is a generic-term that describes a new digital communications network. The network is a digital, bi-directional, multidrop, serial-bus, and communications network used to link isolated field devices, such as controllers, transducers, actuators and sensors. Fieldbus technology may improve quality, reduce costs and increase efficiency because information is transmitted digitally without analog to digital or digital to analog converters, which also minimizes hardware errors. Fieldbus communication is based on two-wire communication, interconnecting all the components in the system. This paper introduces Fieldbus technology in a 60Co sterilization plant.

  8. A water calorimeter for on-site absorbed dose to water calibrations in (60)Co and MV-photon beams including MRI incorporated treatment equipment.

    PubMed

    de Prez, Leon; de Pooter, Jacco; Jansen, Bartel; Aalbers, Tony

    2016-07-01

    In reference dosimetry the aim is to establish the absorbed dose to water, D w, under reference conditions. However, existing dosimetry protocols are not always applicable for rapidly emerging new treatment modalities. For primary standard dosimetry laboratories it is generally not feasible to acquire such modalities. Therefore it is strongly desired that D w measurements with primary standards can be performed on-site in clinical beams for the new treatment modalities in order to characterize and calibrate detectors. To serve this need, VSL has developed a new transportable water calorimeter serving as a primary D w standard for (60)Co and MV-photons including MRI incorporated treatment equipment. Special attention was paid to its operation in different beam geometries and beam modalities including the application in magnetic fields. The new calorimeter was validated in the VSL (60)Co beam and on-site in clinical MV-photon beams. Excellent agreement of 0.1% was achieved with previous (60)Co field calibrations, i.e. well within the uncertainty of the previous calorimeter, and with measurements performed in horizontal and vertical MV-photon beams. k Q factors, determined for two PTW 30013 ionization chambers, agreed very well with available literature data. The relative combined standard uncertainty (k  =  1) for D w measurements in (60)Co and MV-photons is 0.37%. Calibrations are carried out with a standard uncertainty of 0.42% and k Q -factors are determined with a relative standard uncertainty of 0.40%. PMID:27300589

  9. A water calorimeter for on-site absorbed dose to water calibrations in 60Co and MV-photon beams including MRI incorporated treatment equipment

    NASA Astrophysics Data System (ADS)

    de Prez, Leon; de Pooter, Jacco; Jansen, Bartel; Aalbers, Tony

    2016-07-01

    In reference dosimetry the aim is to establish the absorbed dose to water, D w, under reference conditions. However, existing dosimetry protocols are not always applicable for rapidly emerging new treatment modalities. For primary standard dosimetry laboratories it is generally not feasible to acquire such modalities. Therefore it is strongly desired that D w measurements with primary standards can be performed on-site in clinical beams for the new treatment modalities in order to characterize and calibrate detectors. To serve this need, VSL has developed a new transportable water calorimeter serving as a primary D w standard for 60Co and MV-photons including MRI incorporated treatment equipment. Special attention was paid to its operation in different beam geometries and beam modalities including the application in magnetic fields. The new calorimeter was validated in the VSL 60Co beam and on-site in clinical MV-photon beams. Excellent agreement of 0.1% was achieved with previous 60Co field calibrations, i.e. well within the uncertainty of the previous calorimeter, and with measurements performed in horizontal and vertical MV-photon beams. k Q factors, determined for two PTW 30013 ionization chambers, agreed very well with available literature data. The relative combined standard uncertainty (k  =  1) for D w measurements in 60Co and MV-photons is 0.37%. Calibrations are carried out with a standard uncertainty of 0.42% and k Q -factors are determined with a relative standard uncertainty of 0.40%.

  10. Paired organs--Should they be treated jointly or separately in internal dosimetry?

    SciTech Connect

    Parach, Ali-Asghar; Rajabi, Hossein; Askari, Mohammad-Ali

    2011-10-15

    Purpose: Size, shape, and the position of paired organs are different in abdomen. However, the counterpart organs are conventionally treated jointly together in internal dosimetry. This study was performed to quantify the difference of specific absorbed fraction of organs in considering paired organs jointly like single organs or as two separate organs. Methods: Zubal phantom and GATE Monte Carlo package were used to calculate the SAF for the self-absorption and cross-irradiation of the lungs, kidneys, adrenal glands (paired organs), liver, spleen, stomach, and pancreas (single organs). The activity was assumed uniformly distributed in the organs, and simulation was performed for monoenergetic photons of 10, 50, 100, 500, 1000 keV and mono-energetic electrons of 350, 500, 690, 935, 1200 keV. Results: The results demonstrated that self-absorption of left and right counterpart organs may be different depending upon the differences in their masses. The cross-irradiations between left-to-right and right-to-left counterpart organs are always equal irrespective of difference in their masses. Cross-irradiation from the left and right counterpart organs to other organs are different (4-24 times in Zubal phantom) depending on the photon energy and organs. The irradiation from a single source organ to the left and right counterpart paired organs is always different irrespective of activity concentration. Conclusions: Left and right counterpart organs always receive different absorbed doses from target organs and deliver different absorbed doses to target organs. Therefore, in application of radiopharmaceuticals in which the dose to the organs plays a role, counterpart organs should be treated separately as two separate organs.

  11. Physical and biological organ dosimetry analysis for international space station astronauts.

    PubMed

    Cucinotta, Francis A; Kim, Myung-Hee Y; Willingham, Veronica; George, Kerry A

    2008-07-01

    In this study, we analyzed the biological and physical organ dose equivalents for International Space Station (ISS) astronauts. Individual physical dosimetry is difficult in space due to the complexity of the space radiation environment, which consists of protons, heavy ions and secondary neutrons, and the modification of these radiation types in tissue as well as limitations in dosimeter devices that can be worn for several months in outer space. Astronauts returning from missions to the ISS undergo biodosimetry assessment of chromosomal damage in lymphocyte cells using the multicolor fluorescence in situ hybridization (FISH) technique. Individual-based pre-flight dose responses for lymphocyte exposure in vitro to gamma rays were compared to those exposed to space radiation in vivo to determine an equivalent biological dose. We compared the ISS biodosimetry results, NASA's space radiation transport models of organ dose equivalents, and results from ISS and space shuttle phantom torso experiments. Physical and biological doses for 19 ISS astronauts yielded average effective doses and individual or population-based biological doses for the approximately 6-month missions of 72 mSv and 85 or 81 mGy-Eq, respectively. Analyses showed that 80% or more of organ dose equivalents on the ISS are from galactic cosmic rays and only a small contribution is from trapped protons and that GCR doses were decreased by the high level of solar activity in recent years. Comparisons of models to data showed that space radiation effective doses can be predicted to within about a +/-10% accuracy by space radiation transport models. Finally, effective dose estimates for all previous NASA missions are summarized. PMID:18582161

  12. 60Co as AN On-Line Burnup Indicator for Multi-Pass Pebble Bed Reactors

    NASA Astrophysics Data System (ADS)

    Hawari, Ayman I.; Chen, Jianwei

    2003-06-01

    Multi-pass pebble bed reactor concepts are characterized by circulating fuel systems that cycle the pebbles in and out of the core until the burnup limit is reached. Currently modular designs of such reactors, with nominal powers of approximately 300 MW-thermal, are under consideration for deployment internationally. A concern of the proposed designs is the ability to perform online measurements of the fuel burnup to determine whether a pebble has reached its end-of-life burnup limit (~ 80,000 MWD/MTU). In this work, computational simulations were performed to assess the utilization of a passive gamma ray spectrometric approach to perform this task. However, in addition to using the inherent signatures of the irradiated fuel, the use of the 59Co(n,γ)60Co reaction as a burnup indicator is considered. The results show that the activity ratio of 134Cs/60Co can provide an indicator that is accurate to within 5% at burnup greater than 20,000 MWD/MTU as the power is varied between 50% and 200% of the reactor's thermal power.

  13. Skeletal dosimetry in a voxel-based rat phantom for internal exposures to photons and electrons

    SciTech Connect

    Xie Tianwu; Han Dao; Liu Yang; Sun Wenjuan; Liu Qian

    2010-05-15

    Purpose: The skeleton makes a significant contribution to the whole body absorbed dose evaluation of rats, since the bone marrow and bone surface in the skeleton express high radiosensitivity and are considered to be important dose-limiting tissues. The bone marrow can be categorized as red bone marrow (RBM) and yellow bone marrow (YBM). It is important to investigate the bone marrow in skeletal dosimetry. Methods: Cryosectional color images of the skeleton of a 156 g rat were segmented into mineral bone (including cortical bone and trabecular bone), RBM, and YBM. These three tissue types were identified at 40 different bone sites and integrated into a previously developed voxel-based rat computational phantom. Photon and electron skeletal absorbed fractions were then calculated using the MCNPX Monte Carlo code. Results: Absorbed fraction (AF) and specific absorbed fraction (SAF) for mineral bone, RBM, and YBM at the 40 different bone sites were established for monoenergetic photon and electron sources placed in 18 organs and seven bone sites. Discrete photon energy was varied from 0.01 to 5.0 MeV in 21 discrete steps, while 21 discrete electron energies were studied, from 0.1 to 10.0 MeV. The trends and values found were consistent with the results of other researchers [M. G. Stabin, T. E. Peterson, G. E. Holburn, and M. A. Emmons, ''Voxel-based mouse and rat models for internal dose calculations,'' J. Nucl. Med. 47, 655-659 (2006)]. S-factors for the radionuclides {sup 169}Er, {sup 143}Pr, {sup 89}Sr, {sup 32}P, and {sup 90}Y, located in 18 organs and seven bone sites for the skeleton, were calculated and are provided in detail. Conclusions: For internal dose calculations, the AF data reveal that the mineral bone in the rat skeletal system is responsible for significant attenuation of gamma rays, especially at low energies. The photon SAF curves of RBM show that, for photon energies greater than 0.6 MeV, there is an increase in secondary photons emitted from the

  14. Evaluation of a semiautomated lung mass calculation technique for internal dosimetry applications

    SciTech Connect

    Busse, Nathan; Erwin, William; Pan, Tinsu

    2013-12-15

    calculated using the formula (lung HU − air HU)/(tissue HU − air HU), and mass = specific gravity × total volume × 1.04 g/cm{sup 3}.Results: The range of calculated lung masses was 0.51–1.29 kg. The average male and female lung masses during FB CT were 0.80 and 0.71 kg, respectively. The calculated lung mass varied across the respiratory cycle but changed to a lesser degree than did lung volume measurements (7.3% versus 15.4%). Lung masses calculated using deep inspiration breath-hold and average CT were significantly larger (p < 0.05) than were some masses calculated using respiratory-phase and FB CT. Increased voxel size and smooth reconstruction kernels led to high lung mass estimates owing to partial volume effects.Conclusions: Organ mass correction is an important component of patient-specific internal radionuclide dosimetry. Lung mass calculation necessitates scan-based density correction to account for volume changes owing to respiration. The range of lung masses in the authors’ patient population represents lung doses for the same absorbed energy differing from 25% below to 64% above the dose found using reference phantom organ masses. With proper management of acquisition parameters and selection of FB or midexpiration breath hold scans, lung mass estimates with about 10% population precision may be achieved.

  15. Decommissioning of a 60Co unit and estimation of personal doses.

    PubMed

    Lin, K H; Lin, J P; Liu, M T; Chu, T C

    2003-01-01

    Chang-hua Christian Hospital needs to uninstall the 60Co unit. The mode of this 60Co teletherapy unit is SHIMADZU RTGS-10. The original lead head was taken as the source container of this 60Co unit. The source head was dismantled and put into the prepared wooden box, after the source was sealed. This study describes the planning and dismantling of the retirement and transport of the 60Co unit, and personal doses measured during the procedure. This work estimates the doses of radiation received by exposed workers during the dismantling of the machine. The workers received doses of approximately 53 microSv. This study shows that the original lead head can be used as the source container of this 60Co unit. The 60Co machine was smoothly dismantled and transported by conscientious and careful workers, using planned and controlled radiation protection, following the ALARA (as low as reasonably achievable) rule. PMID:14653329

  16. (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.

  17. A computational tool for patient specific dosimetry and radiobiological modeling of selective internal radiation therapy with (90)Y microspheres.

    PubMed

    Kalantzis, Georgios; Leventouri, Theodora; Apte, Aditiya; Shang, Charles

    2015-11-01

    In recent years we have witnessed tremendous progress in selective internal radiation therapy. In clinical practice, quite often, radionuclide therapy is planned using simple models based on standard activity values or activity administered per unit body weight or surface area in spite of the admission that radiation-dose methods provide more accurate dosimetric results. To address that issue, the authors developed a Matlab-based computational software, named Patient Specific Yttrium-90 Dosimetry Toolkit (PSYDT). PSYDT was designed for patient specific voxel-based dosimetric calculations and radiobiological modeling of selective internal radiation therapy with (90)Y microspheres. The developed toolkit is composed of three dimensional dose calculations for both bremsstrahlung and beta emissions. Subsequently, radiobiological modeling is performed on a per-voxel basis and cumulative dose volume histograms (DVHs) are generated. In this report we describe the functionality and visualization features of PSYDT. PMID:26296058

  18. 39th Lauriston S. Taylor Lecture: Dosimetry of Internal Emitters: Contribution of Radiation Protection Bodies and Radiological Events.

    PubMed

    Eckerman, Keith F

    2016-02-01

    Since the early days of the Manhattan Engineer District, Oak Ridge National Laboratory (ORNL) has served to advance the dosimetry models used to set protection standards for radionuclides taken into the body. Throughout the years, this effort benefited significantly from ORNL staff's active participation in national and international scientific bodies. The first such interaction was in 1946 with the National Committee on Radiation Protection (NCRP), chaired by L.S. Taylor, which led to the 1949 to 1953 series of tripartite conferences of experts from Canada, the United Kingdom, and the United States. These conferences addressed the need for standardization of dosimetry models and led to the establishment of an anatomic and physiologic model called "Standard Man," a precursor of the reference worker defined in Publication 23 of the International Commission on Radiological Protection (ICRP). Standard Man was used in setting the maximum permissible concentrations in air and water published in NBS Handbook 52 and subsequent reports by NCRP and ICRP. K.Z. Morgan, then director of the Health Physics Division at ORNL, participated in the tripartite conferences and subsequently established ORNL as a modeling and computational resource for development of radiation protection standards. ORNL's role expanded with participation in the work of the Medical Internal Radiation Dose (MIRD) Committee of the Society of Nuclear Medicine. Results of interactions with the MIRD Committee are evident in the radiation protection guidance for internal emitters in ICRP Publication 30. The annual limit on intake and derived air concentration values tabulated in Publication 30 were computed by an ORNL-based task group of ICRP Committee 2. A few years after the appearance of Publication 30, the Chernobyl nuclear reactor accident made clear the need to develop standard dosimetry models for pre-adult ages as members of the public. In the late 1980s, ICRP began an effort to extend its reference

  19. 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

  20. 3D dosimetry estimation for selective internal radiation therapy (SIRT) using SPECT/CT images: a phantom study

    NASA Astrophysics Data System (ADS)

    Debebe, Senait A.; Franquiz, Juan; McGoron, Anthony J.

    2015-03-01

    Selective Internal Radiation Therapy (SIRT) is a common way to treat liver cancer that cannot be treated surgically. SIRT involves administration of Yttrium - 90 (90Y) microspheres via the hepatic artery after a diagnostic procedure using 99mTechnetium (Tc)-macroaggregated albumin (MAA) to detect extrahepatic shunting to the lung or the gastrointestinal tract. Accurate quantification of radionuclide administered to patients and radiation dose absorbed by different organs is of importance in SIRT. Accurate dosimetry for SIRT allows optimization of dose delivery to the target tumor and may allow for the ability to assess the efficacy of the treatment. In this study, we proposed a method that can efficiently estimate radiation absorbed dose from 90Y bremsstrahlung SPECT/CT images of liver and the surrounding organs. Bremsstrahlung radiation from 90Y was simulated using the Compton window of 99mTc (78keV at 57%). 99mTc images acquired at the photopeak energy window were used as a standard to examine the accuracy of dosimetry prediction by the simulated bremsstrahlung images. A Liqui-Phil abdominal phantom with liver, stomach and two tumor inserts was imaged using a Philips SPECT/CT scanner. The Dose Point Kernel convolution method was used to find the radiation absorbed dose at a voxel level for a three dimensional dose distribution. This method will allow for a complete estimate of the distribution of radiation absorbed dose by tumors, liver, stomach and other surrounding organs at the voxel level. The method provides a quantitative predictive method for SIRT treatment outcome and administered dose response for patients who undergo the treatment.

  1. 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

  2. Internal dosimetry through GATE simulations of preclinical radiotherapy using a melanin-targeting ligand

    NASA Astrophysics Data System (ADS)

    Perrot, Y.; Degoul, F.; Auzeloux, P.; Bonnet, M.; Cachin, F.; Chezal, J. M.; Donnarieix, D.; Labarre, P.; Moins, N.; Papon, J.; Rbah-Vidal, L.; Vidal, A.; Miot-Noirault, E.; Maigne, L.

    2014-05-01

    The GATE Monte Carlo simulation platform based on the Geant4 toolkit is under constant improvement for dosimetric calculations. In this study, we explore its use for the dosimetry of the preclinical targeted radiotherapy of melanoma using a new specific melanin-targeting radiotracer labeled with iodine 131. Calculated absorbed fractions and S values for spheres and murine models (digital and CT-scan-based mouse phantoms) are compared between GATE and EGSnrc Monte Carlo codes considering monoenergetic electrons and the detailed energy spectrum of iodine 131. The behavior of Geant4 standard and low energy models is also tested. Following the different authors’ guidelines concerning the parameterization of electron physics models, this study demonstrates an agreement of 1.2% and 1.5% with EGSnrc, respectively, for the calculation of S values for small spheres and mouse phantoms. S values calculated with GATE are then used to compute the dose distribution in organs of interest using the activity distribution in mouse phantoms. This study gives the dosimetric data required for the translation of the new treatment to the clinic.

  3. 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.

  4. Internal dosimetry through GATE simulations of preclinical radiotherapy using a melanin-targeting ligand.

    PubMed

    Perrot, Y; Degoul, F; Auzeloux, P; Bonnet, M; Cachin, F; Chezal, J M; Donnarieix, D; Labarre, P; Moins, N; Papon, J; Rbah-Vidal, L; Vidal, A; Miot-Noirault, E; Maigne, L

    2014-05-01

    The GATE Monte Carlo simulation platform based on the Geant4 toolkit is under constant improvement for dosimetric calculations. In this study, we explore its use for the dosimetry of the preclinical targeted radiotherapy of melanoma using a new specific melanin-targeting radiotracer labeled with iodine 131. Calculated absorbed fractions and S values for spheres and murine models (digital and CT-scan-based mouse phantoms) are compared between GATE and EGSnrc Monte Carlo codes considering monoenergetic electrons and the detailed energy spectrum of iodine 131. The behavior of Geant4 standard and low energy models is also tested. Following the different authors' guidelines concerning the parameterization of electron physics models, this study demonstrates an agreement of 1.2% and 1.5% with EGSnrc, respectively, for the calculation of S values for small spheres and mouse phantoms. S values calculated with GATE are then used to compute the dose distribution in organs of interest using the activity distribution in mouse phantoms. This study gives the dosimetric data required for the translation of the new treatment to the clinic. PMID:24710744

  5. An image-based skeletal dosimetry model for the ICRP reference newborn—internal electron sources

    NASA Astrophysics Data System (ADS)

    Pafundi, Deanna; Rajon, Didier; Jokisch, Derek; Lee, Choonsik; Bolch, Wesley

    2010-04-01

    In this study, a comprehensive electron dosimetry model of newborn skeletal tissues is presented. The model is constructed using the University of Florida newborn hybrid phantom of Lee et al (2007 Phys. Med. Biol. 52 3309-33), the newborn skeletal tissue model of Pafundi et al (2009 Phys. Med. Biol. 54 4497-531) and the EGSnrc-based Paired Image Radiation Transport code of Shah et al (2005 J. Nucl. Med. 46 344-53). Target tissues include the active bone marrow (surrogate tissue for hematopoietic stem cells), shallow marrow (surrogate tissue for osteoprogenitor cells) and unossified cartilage (surrogate tissue for chondrocytes). Monoenergetic electron emissions are considered over the energy range 1 keV to 10 MeV for the following source tissues: active marrow, trabecular bone (surfaces and volumes), cortical bone (surfaces and volumes) and cartilage. Transport results are reported as specific absorbed fractions according to the MIRD schema and are given as skeletal-averaged values in the paper with bone-specific values reported in both tabular and graphic format as electronic annexes (supplementary data). The method utilized in this work uniquely includes (1) explicit accounting for the finite size and shape of newborn ossification centers (spongiosa regions), (2) explicit accounting for active and shallow marrow dose from electron emissions in cortical bone as well as sites of unossified cartilage, (3) proper accounting of the distribution of trabecular and cortical volumes and surfaces in the newborn skeleton when considering mineral bone sources and (4) explicit consideration of the marrow cellularity changes for active marrow self-irradiation as applicable to radionuclide therapy of diseased marrow in the newborn child.

  6. Comparative uptake from sea water and tissue distribution of 60Co in marine mollusks

    SciTech Connect

    Carvalho, F.P.

    1987-07-01

    Five different species of marine mollusks, Mytilus galloprovincialis Lmk., Tapes decussatus L., Cerastoderma (Cardium) edule (L.), Donax vittatus (da Costa) and Patella vulgata L., were exposed to /sup 60/Co-labelled sea water under laboratory conditions. After a 1-mo exposure, tested species reached different whole-body /sup 60/Co concentration factors (CF) over radioactive sea water of 73 +/- 27, 22 +/- 10, 84 +/- 25, 6.3 +/- 1.4 and 31 +/- 10, respectively, which are not dependent upon the size of mollusks. Equations for the experimental uptake curves, obtained using a multi-exponential model, indicate that /sup 60/Co uptake by mollusks involves two or three compartments, according to the species. In all species, the larger compartments turn over with long biological half-lives, dependent upon species. At the beginning of the experiment, /sup 60/CoCl2 added to sea water was mainly in cationic forms. These forms were progressively converted into anionic plus neutral forms most likely due to complex formation with organic ligands. With time this physico-chemical evolution had a lowering effect on /sup 60/Co bioaccumulation by mollusks. Analysis of /sup 60/Co in tissues revealed that Donax shell and mantle do not accumulate the radionuclide in great quantities, generating the low whole-body concentration factor found. In contrast, shell and mantle from all other species displayed variable but high CFs. Shell by itself accounts for more than half of the /sup 60/Co whole-body burden. Among soft tissues, gills and viscera displayed the highest CF and muscle the lowest. From these experiments, one may conclude that significant differences among species do exist regarding Co bioaccumulation potential.

  7. SU-C-201-06: Utility of Quantitative 3D SPECT/CT Imaging in Patient Specific Internal Dosimetry of 153-Samarium with GATE Monte Carlo Package

    SciTech Connect

    Fallahpoor, M; Abbasi, M; Sen, A; Parach, A; Kalantari, F

    2015-06-15

    Purpose: Patient-specific 3-dimensional (3D) internal dosimetry in targeted radionuclide therapy is essential for efficient treatment. Two major steps to achieve reliable results are: 1) generating quantitative 3D images of radionuclide distribution and attenuation coefficients and 2) using a reliable method for dose calculation based on activity and attenuation map. In this research, internal dosimetry for 153-Samarium (153-Sm) was done by SPECT-CT images coupled GATE Monte Carlo package for internal dosimetry. Methods: A 50 years old woman with bone metastases from breast cancer was prescribed 153-Sm treatment (Gamma: 103keV and beta: 0.81MeV). A SPECT/CT scan was performed with the Siemens Simbia-T scanner. SPECT and CT images were registered using default registration software. SPECT quantification was achieved by compensating for all image degrading factors including body attenuation, Compton scattering and collimator-detector response (CDR). Triple energy window method was used to estimate and eliminate the scattered photons. Iterative ordered-subsets expectation maximization (OSEM) with correction for attenuation and distance-dependent CDR was used for image reconstruction. Bilinear energy mapping is used to convert Hounsfield units in CT image to attenuation map. Organ borders were defined by the itk-SNAP toolkit segmentation on CT image. GATE was then used for internal dose calculation. The Specific Absorbed Fractions (SAFs) and S-values were reported as MIRD schema. Results: The results showed that the largest SAFs and S-values are in osseous organs as expected. S-value for lung is the highest after spine that can be important in 153-Sm therapy. Conclusion: We presented the utility of SPECT-CT images and Monte Carlo for patient-specific dosimetry as a reliable and accurate method. It has several advantages over template-based methods or simplified dose estimation methods. With advent of high speed computers, Monte Carlo can be used for treatment planning

  8. Delayed Mitogenic Stimulation Decreases DNA Damage Assessed by Micronucleus Assay in Human Peripheral Blood Lymphocytes After 60Co Irradiation

    PubMed Central

    Selvan, G. Tamizh; Bhavani, M.; Vijayalakshmi, J.; Paul Solomon, F.D.; Chaudhury, N.K.; Venkatachalam, P.

    2014-01-01

    While contradictory reports are available on the yield of dicentric chromosomes (DC) in blood samples stored at different temperature and stimulated to enter into cell cycle, various times gap followed by exposure, limited information is available on the micronucleus (MN) assay. As scoring the micronuclei frequency from the blood lymphocytes of exposed individuals is an alternative to the gold standard DC assay for triage applications, we examined radiation induced MN yield in delayed mitogenic stimulation after irradiation of in vitro. Peripheral blood lymphocytes (PBL) were exposed to low LET (60Co) radiation dose (0.1 to 5Gy) and incubated at 37°C for 2, 6 and 24 hours. The MN frequency obtained in blood samples stimulated 2 hours post-irradiation showed a dose dependent increase and used to construct the dose-response curve. Further, the results also showed that blood samples stimulated twenty four hours of post-irradiation, a significant reduction (p<0.05) in MN frequencies were obtained when compared to that of blood samples stimulated two hours and six hours after post-irradiation (0.5, 1, 3 and 5Gy). The observed result suggests that the prolonged PBL storage without mitogenic stimulation could lead to interphase cell death and a delayed blood sampling could results in underestimation of dose in biological dosimetry. PMID:25249838

  9. Space Radiation Dosimetry to Evaluate the Effect of Polyethylene Shielding in the Russian Segment of the International Space Station

    NASA Astrophysics Data System (ADS)

    Nagamatsu, Aiko; Casolino, Marco; Larsson, Oscar; Ito, Tsuyoshi; Yasuda, Nakahiro; Kitajo, Keiichi; Shimada, Ken; Takeda, Kazuo; Tsuda, Shuichi; Sato, Tatsuhiko

    As a part of the Alteino Long Term Cosmic Ray measurements on board the International Space Station (ALTCRISS) project, the shielding effect of polyethylene (PE) were evaluated in the Russian segment of the ISS, using active and passive dosimeter systems covered with or without PE shielding. For the passive dosimeter system, PADLES (Passive Dosimeter for Life-Science and Experiments in Space) was used in the project, which consists of a Thermo-Luminescent Dosimeters (TLD) and CR-39 Plastic Nuclear Track Detectors (PNTDs) attached to a radiator. Not only CR-39 PNTD itself but also a tissue equivalent material, NAN-JAERI, were employed as the radiator in order to investigate whether CR-39 PNTD can be used as a surrogate of tissue equivalent material in space dosimetry or not. The agreements between the doses measured by PADLES with CR-39 PNTD and NAN-JAERI radiators were quite satisfactorily, indicating the tissue-equivalent dose can be measured by conventional PADLES even though CR-39 PNTD is not perfect tissue-equivalent material. It was found that the shielding effect of PE varies with location inside the spacecraft: it became less significant with an increase of the mean thickness of the wall. This tendency was also verified by Monte Carlo simulation using the PHITS code. Throughout the flight experiments, in a series of four phases in the ALTCRISS project from December 2005 to October 2007, we assessed the ability of PE to decrease radiation doses in Low Earth Orbit(LEO).

  10. Evaluation of BEBIG HDR 60Co system for non-invasive image-guided breast brachytherapy

    PubMed Central

    Zehtabian, Mehdi; Sina, Sedigheh; Rivard, Mark J.

    2015-01-01

    Purpose HDR 60Co system has recently been developed and utilized for brachytherapy in many countries outside of the U.S. as an alternative to 192Ir. In addition, the AccuBoost® technique has been demonstrated to be a successful non-invasive image-guided breast brachytherapy treatment option. The goal of this project is to evaluate the possibility of utilizing the BEBIG HDR 60Co system for AccuBoost treatment. These evaluations are performed with Monte Carlo (MC) simulation technique. Material and methods In this project, the MC calculated dose distributions from HDR 60Co for various breast sizes have been compared with the simulated data using an HDR 192Ir source. These calculations were performed using the MCNP5 code. The initial calculations were made with the same applicator dimensions as the ones used with the HDR 192Ir system (referred here after as standard applicator). The activity of the 60Co source was selected such that the dose at the center of the breast would be the same as the values from the 192Ir source. Then, the applicator wall-thickness for the HDR 60Co system was increased to diminish skin dose to levels received when using the HDR 192Ir system. With this geometry, dose values to the chest wall and the skin were evaluated. Finally, the impact of a conical attenuator with the modified applicator for the HDR 60Co system was analyzed. Results These investigations demonstrated that loading the 60Co sources inside the thick-walled applicators created similar dose distributions to those of the 192Ir source in the standard applicators. However, dose to the chest wall and breast skin with 60Co source was reduced using the thick-walled applicators relative to the standard applicators. The applicators with conical attenuator reduced the skin dose for both source types. Conclusions The AccuBoost treatment can be performed with the 60Co source and thick-wall applicators instead of 192Ir with standard applicators. PMID:26816504

  11. Aminothiol Receptors for Decorporation of Intravenously Administered 60Co in the Rat

    SciTech Connect

    Levitskaia, Tatiana G.; Morris, James E.; Creim, Jeffrey A.; Woodstock, Angela D.; Luders, Teresa; Curry, Terry L.; Thrall, Karla D.

    2010-01-01

    The reported investigation provides a comparison of the oral decorporation efficacy of L-glutathione (GSH), L-cysteine (Cys), and a liposomal GSH formulation (ReadiSorb) toward systemic cobalt-60 (60Co) to that observed following intravenous administration of GSH and Cys in F344 rats. L-histidine (His) was tested intravenously to compare in vivo efficacy of the aminothiol GSH and Cys chelators with that of aminoimidazole (His) chelator. 60Co was administered to animals by intravenous injection, followed by intravenous or oral gavage doses of a chelator repeated at 24 hour intervals for a total of 5 doses. The results suggest that GSH and Cys are potent decorporation agents for 60Co in the rat model, although the efficacy of treatment depends largely on systemic availability of a chelator. The intravenous GSH or Cys were most effective in reducing tissue 60Co levels and in increasing excretion of radioactivity compared to control animals. Liposomal encapsulation was found to markedly enhance the oral bioavailability of GSH compared to non-formulated GSH. Oral administration of ReadiSorb reduced 60Co levels in nearly all tissues by 12-43% compared to that observed for non-formulated GSH. Efficacy of oral Cys was only slightly reduced in comparison with intravenous Cys. Further studies to optimize the dosing regimen in order to maximize decorporation efficiency are warranted.

  12. Aminothiol receptors for decorporation of intravenously administered (60)Co in the rat.

    PubMed

    Levitskaia, Tatiana G; Morris, James E; Creim, Jeffrey A; Woodstock, Angela D; Luders, Teresa; Curry, Terry L; Thrall, Karla D

    2010-01-01

    This report provides a comparison of the oral decorporation efficacy of L-glutathione (GSH), L-cysteine (Cys), and a liposomal GSH formulation (ReadiSorb) toward systemic (60)Co to that observed following intravenous administration of GSH and Cys in F344 rats. Aminoacid L-histidine (His) containing no thiol functionality was tested intravenously to compare in vivo efficacy of the aminothiol (GSH, Cys) chelators with that of the aminoimidazole (His) chelator. In these studies, (60)Co was administered to animals by intravenous injection, followed by intravenous or oral gavage doses of a chelator repeated at 24-h intervals for a total of 5 doses. The results suggest that GSH and Cys are potent decorporation agents for (60)Co in the rat model, although the efficacy of treatment depends largely on the systemic availability of the chelator. The intravenous route of administration of GSH or Cys was most effective in reducing tissue (60)Co levels and in increasing excretion of radioactivity compared to control animals. Liposomal encapsulation was found to markedly enhance the oral bioavailability of GSH compared to non-formulated GSH. The oral administration of liposomal GSH reduced (60)Co levels in nearly all tissues by 12-43% compared to that observed for non-formulated GSH. Efficacy of oral Cys was only slightly reduced in comparison with intravenous Cys. Further studies to optimize the dosing regimen in order to maximize decorporation efficiency are warranted. PMID:19959951

  13. Aminothiol Receptors for Decorporation of Intravenously Administered 60Co in the Rat

    PubMed Central

    Levitskaia, Tatiana G.; Morris, James E.; Creim, Jeffrey A.; Woodstock, Angela D.; Luders, Teresa; Curry, Terry L.; Thrall, Karla D.

    2009-01-01

    This report provides a comparison of the oral decorporation efficacy of L-glutathione (GSH), L-cysteine (Cys), and a liposomal GSH formulation (ReadiSorb) toward systemic cobalt-60 (60Co) to that observed following intravenous administration of GSH and Cys in F344 rats. Aminoacid L-histidine (His) containing no thiol functionality was tested intravenously to compare in vivo efficacy of the aminothiol (GSH, Cys) chelators with that of aminoimidazole (His) chelator. In these studies, 60Co was administered to animals by intravenous injection, followed by intravenous or oral gavage doses of a chelator repeated at 24 hour intervals for a total of 5 doses. The results suggest that GSH and Cys are potent decorporation agents for 60Co in the rat model, although the efficacy of treatment depends largely on systemic availability of the chelator. The intravenous route of administration of GSH or Cys was most effective in reducing tissue 60Co levels and in increasing excretion of radioactivity compared to control animals. Liposomal encapsulation was found to markedly enhance the oral bioavailability of GSH compared to non-formulated GSH. The oral administration of liposomal GSH reduced 60Co levels in nearly all tissues by 12-43% compared to that observed for non-formulated GSH. Efficacy of oral Cys was only slightly reduced in comparison with intravenous Cys. Further studies to optimize the dosing regimen in order to maximize decorporation efficiency are warranted. PMID:19959951

  14. 60Co contamination in recycled steel resulting in elevated civilian radiation doses: causes and challenges.

    PubMed

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

    1997-09-01

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

  15. [Inspection of inner structure of sealed 60Co sources by the autoradiography with radcolor film].

    PubMed

    Ohnishi, T; Okamoto, S; Furuta, J; Hiraoka, E

    1985-03-01

    In studies using 60Co gamma-ray irradiation, an extremely high dose rate is often required and samples must be placed very near a 60Co source. The dose rate in the vicinity of the source depends on the inner structure of the source. Therefore, it is necessary to examine the distribution of source activity. As a method of the examination an autoradiographic technique using several coloring materials for irradiation was tried. The materials used were "Radcolor film" developed by our center, besides a glass, polymethylmethacrylate (PMMA) and a blue cellophane. Results showed that the autoradiography with Radcolor film is very useful to examine the position, the size and the activity difference of 60Co pieces by the change of color. PMID:4011961

  16. Deep underground measurements of 60Co in steel exposed to the Hiroshima atomic bomb explosion.

    PubMed

    Hult, Mikael; Gasparro, Joël; Vasselli, Roberto; Shizuma, Kiyoshi; Hoshi, Masaharu; Arnold, Dirk; Neumaier, Stefan

    2004-01-01

    When using gamma-ray spectrometry performed deep underground, it is possible to measure 60Co activities down to 0.1 mBq in steel samples of some 100 g without any pre-concentration. It is thus still possible to measure 60Co induced by neutrons from the atomic bomb explosion in Hiroshima in pieces of steel collected at distances up to about 1200 m slant range. The results of non-destructive measurements of eight steel samples are compared with the 1986 Dose Re-Evaluation (DS86) model calculations. PMID:15177340

  17. Modernization of Cross Section Library for VVER-1000 Type Reactors Internals and Pressure Vessel Dosimetry

    NASA Astrophysics Data System (ADS)

    Voloschenko, Andrey; Zaritskiy, Sergey; Egorov, Aleksander; Boyarinov, Viktor

    2016-02-01

    The broad-group library BGL1000_B7 for neutron and gamma transport calculations in VVER-1000 internals, RPV and shielding was carried out on a base of fine-group library v7-200n47g from SCALE-6 system. The comparison of the library BGL1000_B7 with the library v7-200n47g and the library BGL1000 (the latter is using for VVER-1000 calculations) is demonstrated on several calculation and experimental tests.

  18. RADIATION DOSIMETRY OF THE PRESSURE VESSEL INTERNALS OF THE HIGH FLUX BEAM REACTOR.

    SciTech Connect

    HOLDEN,N.E.; RECINIELLO,R.N.; HU,J.P.; RORER,D.C.

    2002-08-18

    In preparation for the eventual decommissioning of the High Flux Beam Reactor after the permanent removal of its fuel elements from the Brookhaven National Laboratory, both measurements and calculations of the decay gamma-ray dose rate have been performed for the reactor pressure vessel and vessel internal structures which included the upper and lower thermal shields, the transition plate, and the control rod blades. The measurements were made using Red Perspex{trademark} polymethyl methacrylate high-level film dosimeters, a Radcal ''peanut'' ion chamber, and Eberline's high-range ion chamber. To compare with measured gamma-ray dose rate, the Monte Carlo MCNP code and geometric progressive Microshield code were used to model the gamma transport and dose buildup.

  19. Radiation Dosimetry of the Pressure Vessel Internals of the High Flux Beam Reactor

    NASA Astrophysics Data System (ADS)

    Holden, Norman E.; Reciniello, Richard N.; Hu, Jih-Perng; Rorer, David C.

    2003-06-01

    In preparation for the eventual decommissioning of the High Flux Beam Reactor after the permanent removal of its fuel elements from the Brookhaven National Laboratory, both measurements and calculations of the decay gamma-ray dose rate have been performed for the reactor pressure vessel and vessel internal structures which included the upper and lower thermal shields, the Transition Plate, and the Control Rod blades. The measurements were made using Red Perspex™ polymethyl methacrylate high-level film dosimeters, a Radcal "peanut" ion chamber, and Eberline's high-range ion chamber. To compare with measured gamma-ray dose rates, the Monte Carlo MCNP code and geometric progressive MicroShield code were used to model the gamma-ray transport and dose buildup.

  20. [Development of the 60Co gamma-ray standard field for therapy-level dosimeter calibration in terms of absorbed dose to water (N(D,w))].

    PubMed

    Fukumura, Akifumi; Mizuno, Hideyuki; Fukahori, Mai; Sakata, Suoh

    2012-01-01

    A primary standard for the absorbed dose rate to water in a 60Co gamma-ray field was established at National Metrology Institute of Japan (NMIJ) in fiscal year 2011. Then, a 60Co gamma-ray standard field for therapy-level dosimeter calibration in terms of absorbed dose to water was developed at National Institute of Radiological Sciences (NIRS) as a secondary standard dosimetry laboratory (SSDL). The results of an IAEA/WHO TLD SSDL audit demonstrated that there was good agreement between NIRS stated absorbed dose to water and IAEA measurements. The IAEA guide based on the ISO standard was used to estimate the relative expanded uncertainty of the calibration factor for a therapy-level Farmer type ionization chamber in terms of absorbed dose to water (N(D,w)) with the new field. The uncertainty of N(D,w) was estimated to be 1.1% (k = 2), which corresponds to approximately one third of the value determined in the existing air kerma field. The dissemination of traceability of the calibration factor determined in the new field is expected to diminish the uncertainty of dose delivered to patients significantly. PMID:24568023

  1. Comparison of 60Co and 192Ir sources in HDR brachytherapy

    PubMed Central

    Zwierzchowski, Grzegorz

    2011-01-01

    This paper compares the isotopes 60Co and 192Ir as radiation sources for high-dose-rate (HDR) afterloading brachytherapy. The smaller size of 192Ir sources made it the preferred radionuclide for temporary brachytherapy treatments. Recently also 60Co sources have been made available with identical geometrical dimensions. This paper compares the characteristics of both nuclides in different fields of brachytherapy based on scientific literature. In an additional part of this paper reports from medical physicists of several radiation therapy institutes are discussed. The purpose of this work is to investigate the advantages or disadvantages of both radionuclides for HDR brachytherapy due to their physical differences. The motivation is to provide useful information to support decision-making procedures in the selection of equipment for brachytherapy treatment rooms. The results of this work show that no advantages or disadvantages exist for 60Co sources compared to 192Ir sources with regard to clinical aspects. Nevertheless, there are potential logistical advantages of 60Co sources due to its longer half-life (5.3 years vs. 74 days), making it an interesting alternative especially in developing countries. PMID:23346129

  2. Directional distributions of beta-rays emitted from polarized 60Co nuclei

    NASA Astrophysics Data System (ADS)

    Chirovsky, L. M.; Lee, W. P.; Sabbas, A. M.; Groves, J. L.; Wu, C. S.

    1980-07-01

    The 60Co nuclei in a thin permendur foil were polarized by a pair of orthogonal magnetic flux loops at ultralow temperatures. The observed angular distribution and the asymmetry factor ( Aexp = -1.01 ± 0.02) are in excellent agreement with theoretical predictions of (1 + α cos θ) dependence and Atheory = -1.0.

  3. Internal dosimetry of nuclear medicine workers through the analysis of (131)I in aerosols.

    PubMed

    Carneiro, Luana Gomes; de Lucena, Eder Augusto; Sampaio, Camilla da Silva; Dantas, Ana Letícia Almeida; Sousa, Wanderson Oliveira; Santos, Maristela Souza; Dantas, Bernardo Maranhão

    2015-06-01

    (131)I is widely used in nuclear medicine for diagnostic and therapy of thyroid diseases. Depending of workplace safety conditions, routine handling of this radionuclide may result in a significant risk of exposure of the workers subject to chronic intake by inhalation of aerosols. A previous study including in vivo and in vitro measurements performed recently among nuclear medicine personnel in Brazil showed the occurrence of (131)I incorporation by workers involved in the handling of solutions used for radioiodine therapy. The present work describes the development, optimization and application of a methodology to collect and analyze aerosol samples aiming to assess internal doses based on the activity of (131)I present in a radiopharmacy laboratory. Portable samplers were positioned at one meter distant from the place where non-sealed liquid sources of (131)I are handled. Samples were collected over 1h using high-efficiency filters containing activated carbon and analyzed by gamma spectrometry with a high-purity germanium detection system. Results have shown that, although a fume hood is available in the laboratory, (131)I in the form of vapor was detected in the workplace. The average activity concentration was found to be of 7.4Bq/m(3). This value is about three orders of magnitude below the Derived Air Concentration (DAC) of 8.4kBq/m(3). Assuming that the worker is exposed by inhalation of iodine vapor during 1h, (131)I concentration detected corresponds to an intake of 3.6Bq which results in a committed effective dose of 7.13×10(-5)mSv. These results show that the radiopharmacy laboratory evaluated is safe in terms of internal exposure of the workers. However it is recommended that the presence of (131)I should be periodically re-assessed since it may increase individual effective doses. It should also be pointed out that the results obtained so far reflect a survey carried out in a specific workplace. Thus, it is suggested to apply the methodology

  4. Investigation of Chitosan for Decorporation of 60Co in the Rat

    SciTech Connect

    Levitskaia, Tatiana G.; Creim, Jeffrey A.; Curry, Terry L.; Luders, Teresa; Morris, James E.; Sinkov, Sergey I.; Woodstock, Angela D.; Thrall, Karla D.

    2009-08-01

    Purpose: The reported investigation is a part of our on-going research aimed at identifying effective in vivo non-toxic decorporation agents and developing new therapies to treat internal contamination with radionuclides. The non-toxic nature of chitosan makes it an especially attractive candidate for unsupervised treatment of the general population in case of radiological/nuclear emergency. In this study, chemically unmodified water-soluble chitosan oligosaccharide of low molecular weight was tested for decorporation of cobalt-60 (Co-60) using a rodent model. Methods: Affinity of chitosan oligosaccharide for Co(II) was tested in vitro under conditions of physiological pH range and ionic strength using combined spectrophotometric and potentiometric titration techniques. Fisher F344 rat model was used for in vivo studies. To evaluate effect of chitosan on ingested Co-60, animals received single oral dose of Co-60 chloride (7 – 13.2 kBq per animal) followed by oral administration of chitosan material (288 – 366 mg per kg body weight); chitosan dosing was repeated in 24 hours. Chitosan was also tested for removal of internalized Co-60. In this study, Co-60 single intravenous injection (7 – 8 kBq per animal) was followed by repetitive oral (300 mg per kg body weight) or intravenous (195 mg per kg body weight) administration of the chitosan material once daily for 5 days. Control animal groups received a single dose of Co-60 without chelator treatment. Excreta was collected daily. Tissues were collected postmortem and analyzed for radioactivity by gamma counting technique. Results: In vitro experiments confirmed binding of Co(II) by chitosan oligosaccharide, formation of mixed cobalt-chitosan-hydroxide complex species was proposed, and stability constants was calculated. Control in vivo studies indicated that about 71% of ingested Co-60 was excreted in two days predominantly through the gastrointestinal tract. For intravenously administered Co-60, urinal excretion

  5. Direct MC conversion of absorbed dose to graphite to absorbed dose to water for 60Co radiation.

    PubMed

    Lye, J E; Butler, D J; Franich, R D; Harty, P D; Oliver, C P; Ramanathan, G; Webb, D V; Wright, T

    2013-06-01

    The ARPANSA calibration service for (60)Co gamma rays is based on a primary standard graphite calorimeter that measures absorbed dose to graphite. Measurements with the calorimeter are converted to the absorbed dose to water using the calculation of the ratio of the absorbed dose in the calorimeter to the absorbed dose in a water phantom. ARPANSA has recently changed the basis of this calculation from a photon fluence scaling method to a direct Monte Carlo (MC) calculation. The MC conversion uses an EGSnrc model of the cobalt source that has been validated against water tank and graphite phantom measurements, a step that is required to quantify uncertainties in the underlying interaction coefficients in the MC code. A comparison with the Bureau International des Poids et Mesures (BIPM) as part of the key comparison BIPM.RI(I)-K4 showed an agreement of 0.9973 (53). PMID:23152147

  6. Investigation of LaBr3:Ce probe for gamma-ray spectroscopy and dosimetry

    NASA Astrophysics Data System (ADS)

    Maghraby, Ahmed M.; Alzimami, K. S.; Alkhorayef, M. A.; Alsafi, K. G.; Ma, A.; Alfuraih, A. A.; Alghamdi, A. A.; Spyrou, N. M.

    2014-02-01

    The main thrust of this work is the investigation of performance of relatively new commercial LaBr3:Ce probe (Inspector 1000™ with LaBr3:Ce crystal) for gamma-ray spectroscopy and dosimetry measurements in comparison to LaCl3:Ce and NaI:Tl scintillators. The crystals were irradiated by a wide range of energies (57Co, 22Na, 18F, 137Cs and 60Co). The study involved recording of detected spectra and measurement of energy resolution, photopeak efficiency, internal radioactivity measurements as well as dose rate. The Monte Carlo package, Geant4 Application for Tomographic Emission (GATE) was used to validate the experiments. Overall results showed very good agreement between the measurements and the simulations. The LaBr3:Ce crystal has excellent energy resolution, energy resolutions of (3.37±0.05)% and (2.98±0.07)% for a 137Cs 662 keV and a 60Co 1332 keV gamma-ray point sources respectively, were recorded. The disadvantage of the lanthanum halide scintillators is their internal radioactivity. Inspector 1000™ with LaBr3:Ce scintillator has shown an accurate and quick dose measurements at Positron Emission Tomography (PET) Units which allows accurate assessment of the radiation dose received by staff members compared to the use of electronic personal dosimeters (EPD).

  7. (60)Co in cast steel matrix: A European interlaboratory comparison for the characterisation of new activity standards for calibration of gamma-ray spectrometers in metallurgy.

    PubMed

    Tzika, Faidra; Burda, Oleksiy; Hult, Mikael; Arnold, Dirk; Marroyo, Belén Caro; Dryák, Pavel; Fazio, Aldo; Ferreux, Laurent; García-Toraño, Eduardo; Javornik, Andrej; Klemola, Seppo; Luca, Aurelian; Moser, Hannah; Nečemer, Marijan; Peyrés, Virginia; Reis, Mario; Silva, Lidia; Šolc, Jaroslav; Svec, Anton; Tyminski, Zbigniew; Vodenik, Branko; Wätjen, Uwe

    2016-08-01

    Two series of activity standards of (60)Co in cast steel matrix, developed for the calibration of gamma-ray spectrometry systems in the metallurgical sector, were characterised using a European interlaboratory comparison among twelve National Metrology Institutes and one international organisation. The first standard, consisting of 14 disc shaped samples, was cast from steel contaminated during production ("originally"), and the second, consisting of 15 similar discs, from artificially-contaminated ("spiked") steel. The reference activity concentrations of (60)Co in the cast steel standards were (1.077±0.019) Bqg(-1) on 1 January 2013 12h00 UT and (1.483±0.022) Bqg(-1) on 1 June 2013 12h00 UT, respectively. PMID:27236833

  8. Measurement of 60Co-gamma ray-induced DNA damage by capillary electrophoresis.

    PubMed

    Nackerdien, Z; Atha, D

    1996-08-01

    Capillary electrophoresis was employed in this study to monitor 60Co-gamma ray-induced damage to a 1 kb DNA ladder which consists of restriction fragments ranging from 75 to 12,000 bp. DNA samples (0.5 mg/ml) were exposed to 0-60 Gy of gamma-radiation in the presence and absence of 110 mumol/l ethidium bromide (EB). The analysis showed peak broadening without significant changes in the size distribution of irradiated fragments. Radiation-induced conformational changes may account for this peak broadening. EB addition caused small increases in the retention times of DNA fragments without affecting the overall DNA damage. This indicates that the presence of intercalated EB during radiation will not stabilize the DNA against 60Co-gamma ray-induced damage. PMID:8876442

  9. Calorimetric study on the effect of 60Co γ-rays on the growth of microorganisms

    NASA Astrophysics Data System (ADS)

    Wirkner, Sandra; Takahashi, Katsutada; Furuta, Masakazu; Hayashi, Toshio

    2002-03-01

    Using a calorimeter equipped with 24 sample units, the heat evolution from growing Saccharomyces cerevisiae, Escherichia coli and spores of Bacillus pumilus and Bacillus stearothermophilus was detected in the form of growth thermograms. Irradiation with 60Co γ-rays affected the growth pattern, which was used for a quantitative analysis of the effect on microorganisms. Irradiation of B. pumilus and B. stearothermophilus spores led to dose-dependent delays in growth, indicating a bactericidal effect. In case of 60Co γ-irradiated S. cerevisiae, a dose-dependent reduction of the growth rate constant was observed together with the retardation in growth, indicating a combination of bactericidal and bacteriostatic effects. An equation to determine the number of survivors on the basis of the retardation in growth tα and the growth rate constant μ was developed, which proved the opportunity to use the calorimetric technique in predictive microbiology.

  10. Dosimetric characterizations of GZP6 60Co high dose rate brachytherapy sources: application of superimposition method

    PubMed Central

    Bahreyni Toossi, Mohammad Taghi; Ghorbani, Mahdi; Mowlavi, Ali Asghar; Meigooni, Ali Soleimani

    2012-01-01

    Background Dosimetric characteristics of a high dose rate (HDR) GZP6 Co-60 brachytherapy source have been evaluated following American Association of Physicists in MedicineTask Group 43U1 (AAPM TG-43U1) recommendations for their clinical applications. Materials and methods MCNP-4C and MCNPX Monte Carlo codes were utilized to calculate dose rate constant, two dimensional (2D) dose distribution, radial dose function and 2D anisotropy function of the source. These parameters of this source are compared with the available data for Ralstron 60Co and microSelectron192Ir sources. Besides, a superimposition method was developed to extend the obtained results for the GZP6 source No. 3 to other GZP6 sources. Results The simulated value for dose rate constant for GZP6 source was 1.104±0.03 cGyh-1U-1. The graphical and tabulated radial dose function and 2D anisotropy function of this source are presented here. The results of these investigations show that the dosimetric parameters of GZP6 source are comparable to those for the Ralstron source. While dose rate constant for the two 60Co sources are similar to that for the microSelectron192Ir source, there are differences between radial dose function and anisotropy functions. Radial dose function of the 192Ir source is less steep than both 60Co source models. In addition, the 60Co sources are showing more isotropic dose distribution than the 192Ir source. Conclusions The superimposition method is applicable to produce dose distributions for other source arrangements from the dose distribution of a single source. The calculated dosimetric quantities of this new source can be introduced as input data to the GZP6 treatment planning system (TPS) and to validate the performance of the TPS. PMID:23077455

  11. Low level measurement of (60)Co by gamma ray spectrometry using γ-γ coincidence.

    PubMed

    Paradis, H; de Vismes Ott, A; Luo, M; Cagnat, X; Piquemal, F; Gurriaran, R

    2016-03-01

    This paper presents the latest development of the laboratory to measure the natural and artificial massic activities in environmental samples. The measurement method of coincident emitters by gamma-gamma coincidence using an anti-Compton device and its digital electronics is described. Results obtained with environmental samples are shown. Despite its low efficiency, this method decreases detection limits of (60)Co for certain samples compared to conventional gamma-ray spectrometry due to its very low background. PMID:26682892

  12. CYTOGENETIC COMPARISON OF THE RESPONSES OF MOUSE AND HUMAN PERIPHERAL BLOOD LYMPHOCYTES TO 60CO GAMMA RADIATION (JOURNAL VERSION)

    EPA Science Inventory

    Experiments were conducted to compare the chromosome damaging effects of (60)Co gamma radiation on mouse and human peripheral blood lymphocytes (PBLs). Either whole blood or isolated and pelleted mononuclear leucocytes (MNLs) were irradiated with a (60)Co unit to yield exposures ...

  13. Decoloration Kinetics of Waste Cooking Oil by 60Co γ-ray/H2O2

    NASA Astrophysics Data System (ADS)

    Xiang, Yulin; Xiang, Yuxiu; Wang, Lipeng

    2016-03-01

    In order to decolorize, waste cooking oil, a dark red close to black solution from homes and restaurants, was subjected to 60Co γ-ray/H2O2 treatment. By virtue of UV/Vis spectrophotometric method, the influence of Gamma irradiation to decoloration kinetics and rate constants of the waste cooking oil in the presence of H2O2 was researched. In addition, the influence of different factors such as H2O2 concentration and irradiation dose on the decoloration rate of waste cooking oil was investigated. Results indicated that the decoloration kinetics of waste cooking oil conformed to the first-order reaction. The decoloration rate increased with the increase of irradiation dose and H2O2 concentration. Saponification analysis and sensory evaluation showed that the sample by 60Co γ-ray/H2O2 treatment presented better saponification performance and sensory score. Furthermore, according to cost estimate, the cost of the 60Co γ-ray/H2O2 was lower and more feasible than the H2O2 alone for decoloration of waste cooking oil.

  14. 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.

  15. Comparison of internal dosimetry factors for three classes of adult computational phantoms with emphasis on I-131 in the thyroid

    NASA Astrophysics Data System (ADS)

    Lamart, Stephanie; Bouville, Andre; Simon, Steven L.; Eckerman, Keith F.; Melo, Dunstana; Lee, Choonsik

    2011-11-01

    source region for selected target organs—small intestine wall, lungs, pancreas and breast—as well as illustrate differences in energy deposition across the energy range (12 photon energies from 0.01 to 4 MeV). Differences were found in the SAFs between phantoms in a similar manner as the differences observed in S values but with larger differences at lower photon energies. To investigate the differences observed in the S and SAF values, the chord length distributions (CLDs) were computed for the selected source-target pairs and compared across the phantoms. As demonstrated by the CLDs, we found that the differences between phantoms in those factors used in internal dosimetry were governed to a significant degree by inter-organ distances which are a function of organ shape as well as organ location.

  16. COMPARISON OF INTERNAL DOSIMETRY FACTORS FOR THREE CLASSES OF ADULT COMPUTATIONAL PHANTOMS WITH EMPHASIS ON I-131 IN THE THYROID

    PubMed Central

    Lamart, Stephanie; Bouville, Andre; Simon, Steven L.; Eckerman, Keith F.; Melo, Dunstana; Lee, Choonsik

    2012-01-01

    target organs - small intestine wall, lungs, pancreas and breast as well as illustrate differences in energy deposition across the energy range (12 photon energies from 0.01 to 4 MeV). Differences were found in SAFs between phantoms in a similar manner to the differences observed in S values but with larger differences at lower photon energies. To investigate the differences observed in S and SAF values, the chord length distributions (CLDs) were computed for the selected source-target pairs and compared across the phantoms. As demonstrated by the CLDs, we found that the differences between phantoms in those factors used in internal dosimetry were governed to a significant degree by inter-organ distances which are a function of organ shape as well as organ location. PMID:22040775

  17. Behavior of 60Co and 134Cs in a Canadian Shield lake over 5 years.

    PubMed

    Bird, G A; Schwartz, W J; Motycka, M; Rosentreter, J

    1998-04-01

    Radionuclides were added to the anoxic hypolimnion of a Canadian Shield lake to simulate the nuclear fuel waste disposal scenario where radionuclides might enter the bottom waters of a lake. The radionuclides remained in the hypolimnion until lake mixing at autumn turnover after which 60Co was rapidly lost and 134Cs was slowly lost from the water. Only 0.4% of the 60Co and 0.6% of the 134Cs remained in the water at year 5. Highest concentrations occurred in periphyton and filter feeders, Holopedium gibberum and clams (Anodonata grandis grandis). From maximum annual concentrations in clam tissues, it was estimated that the availability of 60Co for uptake had a half-time (t1/2) of 835 days in the lake, whereas that for 134Cs was 780 days. Loss rate coefficients, k, for the radionuclides from taxa ranged from 0.0008 to 0.0043 day-1 (t1/2 = 161-866 days) for 60Co and from 0.0009 to 0.005 day-1 (t1/2 = 139-770 days) for 134Cs. Cobalt-60 concentrations in forage fish were low, whereas 134Cs concentrations increased over the first year or two, then slowly declined. On the basis of k values measured for forage fish, the biological half-time of 134Cs in forage fish ranged from 428 to 630 days. Maximum 134Cs concentrations in forage fish were higher following hypolimnetic addition than epilimnetic addition. Relatively high 134Cs concentrations in periphyton at year 5 point to the importance of benthic pathways in the recycling of contaminants to higher trophic levels. The presence of 134Cs in biota 5 years after the addition, long after concentrations were no longer detectable in surface waters, is evidence of the persistence of Cs in aquatic systems. The k values (or t1/2 values) for the loss of 60Co and 134Cs from water and their uptake and loss from biota can be used to establish parameter values for assessment models. The results demonstrate that assessment models should account for the release of radionuclides from sediment and their subsequent recycling in the food

  18. Laser heated thermoluminescence dosimetry

    SciTech Connect

    Justus, B.L.; Huston, A.L.

    1996-06-01

    We report a novel laser-heated thermoluminescence dosimeter that is radically different from previous laser-heated dosimeters. The dosimeter is a semiconductor and metal ion doped silica glass that has excellent optical transparency. The high optical quality of the glass essentially eliminates laser power loss due to light scattering. This efficient utilization of the laser power permits operation of the dosimeter without strong absorption of the laser, as is required in traditional laser-heated dosimetry. Our laser-heated dosimeter does not rely on the diffusion of heat from a separate, highly absorbing substrate, but operates via intimate, localized heating within the glass dosimeter due to the absorption of the laser light by rare earth ion dopants in the glass. Following absorption of the laser light, the rare earth ions transfer energy to the surrounding glass via nonradiative relaxation processes, resulting in rapid, localized temperature increases sufficient to release all the filled traps near the ions. As the heat diffuses radially away from the rare earth ions the temperature plummets dramatically on a manometer distance scale and the release of additional filled traps subsides. A key distinguishing feature of this laser-heated dosimeter is the ability to read the dose information more than once. While laser-heating provides complete information about the radiation exposure experienced by the glass due to the release of locally heated traps, the process leaves the remaining filled bulk traps undisturbed. The bulk traps can be read using traditional bulk heating methods and can provide a direct determination of an accumulated dose, measured following any number of laser-heated readouts. Laser-heated dosimetry measurements have been performed using a solid state diode laser for the readout following radiation exposure with a {sup 60}Co source.

  19. Technical Note: EGSnrc-based dosimetric study of the BEBIG {sup 60}Co HDR brachytherapy sources

    SciTech Connect

    Selvam, T. Palani; Bhola, Subhalaxmi

    2010-03-15

    Purpose: The purpose of this work is to calculate two-dimensional (2D) dose rate distributions around the BEBIG (Eckert and Ziegler, BEBIG GmbH, Germany) models GK60M21 (old) and Co0.A86 (new) {sup 60}Co high dose rate brachytherapy sources in an unbounded liquid water phantom. The study includes calculation of absorbed dose to water-kerma ratio D/K around the BEBIG sources and a {sup 60}Co point source in water. A comparison is made with previously published data. Methods: The EGSnrcMP Monte Carlo code system is used to calculate the absorbed dose and water-kerma in water and air-kerma strength in vacuum. EGSnrcMP-based user codes such as EDKnrc, FLURZnrc, and DOSRZnrc are employed in the work. Results: The value of D/K reaches a maximum of 1.040{+-}0.002 for the {sup 60}Co point source (constant between 3.6 and 4.5 mm from the source) and 1.076{+-}0.002 for the BEBIG sources (constant between 2.6 and 3.2 mm along the transverse axis of the sources). Dose rate data for the new and old sources are comparable to published data for radial distances r>0.5 cm. Differences up to 9% are observed at points close to the source (r=0.25 cm). In addition for the new source, compared to previously published data, dose rate data are higher by 14% along the longitudinal axis where the source cable is connected. Dose rate differences on the longitudinal axis ({theta}=180 deg.) of this source are explained by varying the length of the simulated source cable. Conclusions: The 2D rectangular data set calculated in the present work could be considered for quality control on radiotherapy treatment planning systems.

  20. Experimental studies of combination of PDT and tumor chemotherapy or 60Co irradiation

    NASA Astrophysics Data System (ADS)

    Didziapetriene, Janina; Prasmickiene, Grazina; Sukeliene, Dalija; Rotomskis, Ricardas; Streckyte, Giedre; Atkocius, Vydmantas; Staciokiene, Laima; Smilgevicius, Valerijus

    1995-01-01

    We present experimental results obtained by combining photodynamic therapy (PDT) with tumor chemotherapy or radiotherapy. Dimethoxyhematoporphyrin (DMHp) and photosan (PS) were used as photosensitizers, pharanoxi and vincristine as antitumor drugs. The therapeutic effect of the combination of PDT and antitumor drugs (pharanoxi, vincristine) slightly increases as compared to the treatment of PDT or antitumor drug alone. The additive therapeutic effect is achieved under the combination of PDT and 60Co irradiation. It seems that the sensitizers DMHp and PS regulate lipid peroxidation in blood serum of experimental animals, which becomes more active under the influence of alkylating antitumor drugs. Therefore, they could protect an organism from negative influence of tumor chemotherapy.

  1. Effect of 60Co-gamma radiation on the binding properties in furs

    NASA Astrophysics Data System (ADS)

    Raina, R. K.

    New Zealand white rabbit pelts were pickled by the usual procedure and were tanned with basic aluminium sulphate, basic chromium sulphate and their combinations. Tanned furs were irradiated with 60Co-gamma radiations in the dose range of 5.0-114.0 kGy. The effect of radiation on the binding properties of various added substances like mineral tannins, fats, moisture and shrinkage temperature has been assessed by their comparison with the control samples. The results of these investigations show that radiation on furs causes detannage, increases the moisture and bound fat content and decreases the shrinkage temperature of the furs.

  2. 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.

  3. 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.

  4. Analysis of errors detected in external beam audit dosimetry program at Mexican radiotherapy centers

    NASA Astrophysics Data System (ADS)

    Álvarez-Romero, José T.; Tovar-Muñoz, Víctor M.

    2012-10-01

    Presented and analyzed are the causes of deviation observed in the pilot postal dosimetry audit program to verify the absorbed dose to water Dw in external beams of teletherapy 60Co and/or linear accelerators in Mexican radiotherapy centers, during the years 2007-2011.

  5. Spread of 60Co contaminated steel and its legal consequences in Taiwan.

    PubMed

    Hwang, J Y; Chang, J B; Chang, W P

    2001-12-01

    Since 1992, over 200 civilian residential and school buildings in Taiwan have been identified to have contained 60Co contaminated steel rebar emitting excessive gamma-radioactivity in living environments. These buildings were mostly constructed in early 1983 and 1984 by employing steels from one steel mill, which had recycled unknown 60Co orphan sources in northern Taiwan. In 1994, a group of residents who once stayed for a protracted period up to 10 y in the contaminated Ming-Sheng Villa filed a civil action against Taiwan's nuclear regulatory office, the Atomic Energy Council, for state tort compensation of 3.4 M U.S. dollars in equivalent. After three years of court processes, the Taipei District Court handed down a decision in partial favor of the exposed residents. Both parties soon appealed against this judgment to the Taiwan Appellate Court. This article analyzes the main legal issues involved, including government's obligations to prevent and eliminate contamination, to take preventive measures, and to take necessary remedial measures; and plaintiffs' assertion on any legal right against governmental offices. Moreover, discussion issues contain the scope of damage and compensation, causation analysis, absence of effective and efficient regulation over radioactive contamination, limit of tort compensation law and compensation amount, weight of medical evidence as well as role of expert witnesses, and related comparative legal studies. PMID:11725883

  6. Characterization of the intercalate C60(CO2)x by powder neutron diffraction

    NASA Astrophysics Data System (ADS)

    James, M.; Kennedy, S. J.; Elcombe, M. M.; Gadd, G. E.

    1998-12-01

    The intercalate compound C60(CO2)x has been synthesized by hot isostatically pressing C60 under 170 MPa of CO2 and 350 °C. Neutron powder diffraction studies conducted on C60(CO2)x between room temperature and 5 K have been analyzed using Rietveld techniques and reveal a structural transition between a high-temperature (>~250 K) face-centered cubic phase [Fm3¯m, a=14.224(2) Å (293 K)] and a low-temperature (<~150 K) monoclinic phase [P21/n, a=9.7438(9) Å, b=9.7473(9) Å, c=14.6121(11) Å, β=90.390(6)° (5 K)]. The CO2 molecules occupy the octahedral interstices between the C60 molecules and are oriented along the body diagonal of the high-temperature phase. In the low-temperature phase they are tilted slightly away from the c axis so as to place the oxygen atoms adjacent to the center of a pentagonal face on the C60 molecules.

  7. Adsorption and desorption kinetics of (60)Co and (137)Cs in fresh water rivers.

    PubMed

    Fiengo Pérez, Fabricio; Sweeck, Lieve; Bauwens, Willy; Van Hees, May; Elskens, Marc

    2015-11-01

    Radionuclides released in water systems--as well as heavy metals and organic toxicants--sorb to both the suspended solid particles and the bed sediments. Sorption is usually represented mathematically by the distribution coefficient. This approach implies equilibrium between phases and instantaneous fixation (release) of the pollutant onto (from) the surface of the soil particle. However, empirical evidence suggests that for some radionuclides the fixation is not achieved instantaneously and that the reversibility of the process can be slow. Here the adsorption/desorption kinetics of (60)Co and (137)Cs in fresh water environments were simulated experimentally and later on modelled mathematically, while the influence of the most relevant factors affecting the sorption were taken into account. The experimental results suggest that for adsorption and the desorption more than 24 h are needed to reach equilibrium, moreover, It was observed that the desorption rate constants for (60)Co and (137)Cs lie within ranges which are of two to three orders of magnitude lower than the adsorption rate constants. PMID:26218323

  8. Development of a portable graphite calorimeter for radiation dosimetry.

    PubMed

    Sakama, Makoto; Kanai, Tatsuaki; Fukumura, Akifumi

    2008-01-01

    We developed and performance-tested a portable graphite calorimeter designed to measure the absolute dosimetry of various beams including heavy-ion beams, based on a flexible and convenient means of measurement. This measurement system is fully remote-controlled by the GPIB system. This system uses a digital PID (Proportional, Integral, Derivative) control method based on the LabVIEW software. It was possible to attain stable conditions in a shorter time by this system. The standard deviation of the measurements using the calorimeter was 0.79% at a dose rate of 0.8 Gy/min in 17 calorimeter runs for a (60)Co photon beam. The overall uncertainties for the absorbed dose to graphite and water of the (60)Co photon beam using the developed calorimeter were 0.89% and 1.35%, respectively. Estimations of the correction factors due to vacuum gaps, impurities in the core, the dose gradient and the radiation profile were included in the uncertainties. The absorbed doses to graphite and water irradiated by the (60)Co photon beam were compared with dosimetry measurements obtained using three ionization chambers. The absorbed doses to graphite and water estimated by the two dosimetry methods agreed within 0.1% and 0.3%, respectively. PMID:21976250

  9. Reference Dosimetry for Fast Neutron and Proton Therapy

    SciTech Connect

    Jones, D.T.L.

    2005-05-24

    Fast neutrons and protons undergo fundamentally different interactions in tissue. The former interact with nuclei, while the latter, as in the case of photons, interact mainly with atomic electrons. Protons do, however, also undergo some nuclear interactions, the probability of which increases with energy. For both modalities the practical instruments for determining the reference absorbed dose in a patient are ionization chambers. These provide indirect determination of absorbed dose because calibration factors measured in standard radiation fields, as well as conversion factors that require knowledge of various physical data, have to be applied. All dosimetry protocols recommend that reference absorbed dose measurements in the clinical situation be made with ionization chambers having 60Co calibration factors traceable to standards laboratories. Neutron doses determined with the current internationally accepted protocol (ICRU Report 45 [1989]) have a relative uncertainty of {+-}4.3% (1{sigma}), while proton doses determined with the two protocols (ICRU Report 59 [1998] and IAEA Report TRS 398 [2000]) presently in use have relative uncertainties (1{sigma}) of {+-}2.6 % and {+-}2.0%, respectively.

  10. Dose assessment for ingestion of a 330 kilobecquerel 60Co hot particle.

    PubMed

    Whillans, D W; Chase, W J; Wolodarsky, W H

    2007-01-01

    On leaving the irradiated fuel bay at Pickering A nuclear power station, a worker triggered a whole body monitor alarm with activity in or on his head, and despite careful decontamination techniques he subsequently swallowed a hot particle. Over the next 3 d, the radioactivity was tracked through the body. It was then excreted in a single faecal sample and recovered for physical and radiochemical analysis. This analysis demonstrated that the particle contained 330 kBq of 60Co and only traces of other radioactivity. Its dimensions were approximately 50-130 microm and its composition was consistent with that of Stellite 6. A dose assessment was carried out taking into account the residence time of the particle in the mouth and its transit through the body. The estimated committed effective dose was 1.4 mSv, and the equivalent dose to the maximally exposed 1 cm2 of skin, 81 mSv. PMID:17556340

  11. Tracer diffusion of /sup 60/Co and /sup 63/Ni in amorphous NiZr alloy

    SciTech Connect

    Hoshino, K.; Averback, R.S.; Hahn, H.; Rothman, S.J.

    1987-01-01

    Tracer diffusion of /sup 60/Co and /sup 63/Ni in equiatomic amorphous NiZr alloy in the temperature range between 486 and 641/sup 0/K can be described by: D/sub Co/sup */ = 3.7 x 10/sup -7/ exp(-(135 +- 14) kJ mole/sup -1//RT) m/sup 2//sec and D/sub Ni//sup */ = 1.7 x 10/sup -7/ exp(-(140 +- 9) kJ mole/sup -1//RT) m/sup 2//sec. The values of D/sub Ni//sup */ are in reasonable agreement with those measured by the Rutherford backscattering technique. The measured diffusivities were independent of time, indicating that no relaxation took place during diffusion. 27 refs., 2 tabs.

  12. Recurrence of posterior uveal melanoma after /sup 60/Co episcleral plaque therapy

    SciTech Connect

    Karlsson, U.L.; Augsburger, J.J.; Shields, J.A.; Markoe, A.M.; Brady, L.W.; Woodleigh, R.

    1989-03-01

    The authors analyzed the clinical and follow-up data on 277 selected patients with primary choroidal or ciliochoroidal melanoma who were treated with /sup 60/Co plaque radiotherapy between 1976 and 1982. Local recurrence of the irradiated melanoma developed in 39 (14%) patients during the follow-up interval. The 5-year tumor recurrence rate (Kaplan-Meier) was estimated to be 12%. Multivariate prognostic factor analysis (Cox proportional hazards modeling) identified the largest linear tumor dimension and proximity of the posterior margin of the tumor to the optic nerve head as predictors of recurrence. The 5-year survival rate of patients whose tumors recurred (58%) was significantly (log-rank test P = 0.0023) worse than that of patients whose tumor remained clinically controlled (82%).

  13. Radiation esophagitis in the opossum: radioprotection with indomethacin. [/sup 60/Co

    SciTech Connect

    Northway, M.G.; Libshitz, H.I.; Osborne, B.M.; Feldman, M.S.; Mamel, J.J.; West, J.H.; Szwarc, I.A.

    1980-05-01

    Twenty-five opossums were evaluated before irradiation by fiberoptic endoscopy and air-contrast barium esophagram examination. All animals received 2250 rad /sup 60/Co-irradiated in a single exposure to the entire esophagus and lower exophageal sphincter. Animals received treatment with indomethacin. Acute esophagitis occurred 7 to 10 days postirradiation in control animals and was characterized by erythema, ulceration, and sloughing of esophageal mucosa as determined by air-contrast barium esophagram, endoscopy, and histology. Prostaglandin-treated animals showed more severe evidence of esophagitis than control animals. Indomethacin-treated animals showed no signs or only mild esophagitis posttreatment. It is concluded that indomethacin treatment may significantly reduce the severity of radiation esophagitis perhaps by blockade of prostaglandin synthesis.

  14. Assessing deposition levels of 55Fe, 60Co and 63Ni in the Ignalina NPP environment.

    PubMed

    Gudelis, A; Druteikiene, R; Luksiene, B; Gvozdaite, R; Nielsen, S P; Hou, X; Mazeika, J; Petrosius, R

    2010-06-01

    Two RBMK-1500 reactor units operated in Lithuania in the 1987-2004 period (one of them was stopped for decommissioning in 2004). This study presents a preliminary investigation of surface deposition density levels of (55)Fe and (63)Ni in moss samples collected in the close vicinity of the Ignalina NPP. Non-destructive analysis by the HPGe gamma-spectrometry was followed by radiochemical separation. Radiochemical analysis was based on anion-exchange and extraction chromatography. (55)Fe and (63)Ni activities were measured by liquid scintillation counting (LSC). The results indicate that the deposition values of (55)Fe are generally higher than those of (60)Co and (63)Ni. PMID:18818005

  15. EVALUATION OF THE MIGRATION POTENTIAL FOR 60Co AND 137Cs AT THE MAINE YANKEE SITE.

    SciTech Connect

    FUHRMANN,M.SULLIVAN,T.

    2002-08-08

    The objective of this report is to discuss the degree of sorption and desorption of {sup 137}Cs and {sup 60}Co that may be associated with the granite bedrock and the ''popcorn'' cement drain system that underlie the Maine Yankee Containment Foundation. The purpose is to estimate how much retardation of these two radionuclides takes place in groundwater that flows in the near-field of the Containment Foundation, specifically with respect to contamination originating at the PAB Test Pit. Specific concerns revolve around the potential for the contamination originating near the PAB to create a radioactive dose to a hypothetical ''resident farmer'' using a well intercepting this water to exceed 4 millirems/yr.

  16. Radiation damage of PbWO 4 crystals due to irradiation by 60Co gamma rays

    NASA Astrophysics Data System (ADS)

    Kozma, Peter; Bajgar, Robert; Kozma, Petr

    2002-09-01

    Radiation resistivity of large tungstate crystals PbWO 4 from three suppliers has been studied for doses 10 4 Gy (10 6 rad) and 10 5 Gy (10 7 rad). Radiation resistivity was examined by the measurement of optical transmission through tungstate crystals before and after 60Co gamma-ray irradiations. The absolute degradation of transmission for 10 4 and 10 5 Gy doses at 480 nm wavelength of the peak emission of PbWO 4 doped with La 2+, was found to be lower than 12.3% and 14.2%, respectively. The results have been also compared with radiation hardness measurements for a large volume CeF 3 scintillation crystal. Complete recovery of radiation damage was observed between 10 and 15 days after irradiations.

  17. EGSnrc Monte Carlo-aided dosimetric studies of the new BEBIG 60Co HDR brachytherapy source

    PubMed Central

    Akramuzzaman, Mir Md.; Zakaria, Golam Abu

    2013-01-01

    Purpose The purpose of this study is to obtain the dosimetric parameters of the new BEBIG 60Co brachytherapy source following by TG-43U1 recommendation with appropriate electron cutoff energy (0.521 MeV). Material and methods The new BEBIG 60Co brachytherapy source is used to calculate the TG-43U1 parameters. EGSnrc-based Monte Carlo simulation code has been used to calculate the radial dose functions and anisotropy functions. 2D dose rate table is obtained with Cartesian coordinate system for surrounding the source. Results The radial dose functions are calculated for the distance of 0.06 cm to 100 cm from the source center with different cutoff energies and compared. The anisotropy functions values are calculated with the range of 1° to 179°, and apart from 0.2 cm to 20 cm of radial distances. The along-away dose rate data are calculated for quality assurance purposes. The calculated values are compared with the consensus data set and previous published results. Conclusions The radial dose function values from 0.06 cm to 0.16 cm are low, and these values gradually increased up to 0.3 cm radial distance. The radial dose function values are compared with the values of consensus data set using EGSnrc code system, and it is in good agreement with the published data range. The data for < 0.1 cm is not available in consensus data set, and extrapolated value is included for 0 distances which is the same as the value of 0.1 cm. In this study, the obtained values are strictly fall-off to < 0.1 cm distances. Good agreement with the published data was observed, except the values less than 40° angle at 0.5 cm distance for anisotropy function values. PMID:24143150

  18. 60Co irradiation for sterilization of veterinary mastitis products containing antibiotics and steroids

    NASA Astrophysics Data System (ADS)

    Tsuji, K.; Kane, M. P.; Rahn, P. D.; Steindler, K. A.

    Effects of 60Co irradiation for sterilization of veterinary mastitis products were evaluated. The mastitis products which were examined contained various combinations of antibiotics and steroids suspended in peanut oil vehicle. Bioburden data indicated that the unirradiated products were only occasionally contaminated with microorganisms. The D-values of the nonsterile product and environmental isolates were 0.028, 0.15, 0.017, and 0.018 Mrads for Aspergillus fumigatus, Penicillium oxalicum, Pseudomonas aeruginosa, and Pseudomonas maltophilia, respectively. The D-value of the biological indicator organism, Bacillus pumilus spores, in the vehicle was 0.27 Mrads. Thus, an irradiation dose of 1.6 Mrads would be sufficient to achieve six log cycles of destruction of the biological indicator organism. The minimum absorbed irradiation dose of 2.5 Mrads preferred by many countries for sterilization would achieve 9.3 log cycle destruction of the indicator organism and guarantee a probability of 1 × 10 -15 assurance for the most radio-resistant product isolate, Penicillium oxalicum. In order to examine short and long term chemical stabilities of active components, stability indicating high-performance liquid chromatographic (HPLC) methods for the determination of the following antibiotics and steroids were developed. They were: dihydrostreptomycin, neomycin, novobiocin, penicillin G, hydrocortisone acetate, hydrocortisone sodium succinate, and prednisolone. The rates of degradation and radiolytic degradation schemes for the majority of these compounds were elucidated. Formation of new compounds was not observed in these antibiotics and steroids upon 60Co irradiation. The compounds that increased by irradiation were inherently present in commercially available non-irradiated lots and/or can easily be formed by either acidic, basic, or thermal treatment.

  19. Quality of Intensity Modulated Radiation Therapy Treatment Plans Using a {sup 60}Co Magnetic Resonance Image Guidance Radiation Therapy System

    SciTech Connect

    Wooten, H. Omar Green, Olga; Yang, Min; DeWees, Todd; Kashani, Rojano; Olsen, Jeff; Michalski, Jeff; Yang, Deshan; Tanderup, Kari; Hu, Yanle; Li, H. Harold; Mutic, Sasa

    2015-07-15

    Purpose: This work describes a commercial treatment planning system, its technical features, and its capabilities for creating {sup 60}Co intensity modulated radiation therapy (IMRT) treatment plans for a magnetic resonance image guidance radiation therapy (MR-IGRT) system. Methods and Materials: The ViewRay treatment planning system (Oakwood Village, OH) was used to create {sup 60}Co IMRT treatment plans for 33 cancer patients with disease in the abdominal, pelvic, thorax, and head and neck regions using physician-specified patient-specific target coverage and organ at risk (OAR) objectives. Backup plans using a third-party linear accelerator (linac)-based planning system were also created. Plans were evaluated by attending physicians and approved for treatment. The {sup 60}Co and linac plans were compared by evaluating conformity numbers (CN) with 100% and 95% of prescription reference doses and heterogeneity indices (HI) for planning target volumes (PTVs) and maximum, mean, and dose-volume histogram (DVH) values for OARs. Results: All {sup 60}Co IMRT plans achieved PTV coverage and OAR sparing that were similar to linac plans. PTV conformity for {sup 60}Co was within <1% and 3% of linac plans for 100% and 95% prescription reference isodoses, respectively, and heterogeneity was on average 4% greater. Comparisons of OAR mean dose showed generally better sparing with linac plans in the low-dose range <20 Gy, but comparable sparing for organs with mean doses >20 Gy. The mean doses for all {sup 60}Co plan OARs were within clinical tolerances. Conclusions: A commercial {sup 60}Co MR-IGRT device can produce highly conformal IMRT treatment plans similar in quality to linac IMRT for a variety of disease sites. Additional work is in progress to evaluate the clinical benefit of other novel features of this MR-IGRT system.

  20. Dosimetry for ocular proton beam therapy at the Harvard Cyclotron Laboratory based on the ICRU Report 59.

    PubMed

    Newhauser, W D; Burns, J; Smith, A R

    2002-09-01

    The Massachusetts General Hospital, the Harvard Cyclotron Laboratory (HCL), and the Massachusetts Eye and Ear Infirmary have treated almost 3000 patients with ocular disease using high-energy external-beam proton radiation therapy since 1975. The absorbed dose standard for ocular proton therapy beams at HCL was based on a fluence measurement with a Faraday cup (FC). A majority of proton therapy centers worldwide, however, use an absorbed dose standard that is based on an ionization chamber (IC) technique. The ion chamber calibration is deduced from a measurement in a reference 60Co photon field together with a calculated correction factor that takes into account differences in a chamber's response in 60Co and proton fields. In this work, we implemented an ionization chamber-based absolute dosimetry system for the HCL ocular beamline based on the recommendations given in Report 59 by the International Commission on Radiation Units and Measurements. Comparative measurements revealed that the FC system yields an absorbed dose to water value that is 1.1% higher than was obtained with the IC system. That difference is small compared with the experimental uncertainties and is clinically insignificant. In June of 1998, we adopted the IC-based method as our standard practice for the ocular beam. PMID:12349914

  1. Effect of Gold Nanoparticles on Prostate Dose Distribution under Ir-192 Internal and 18 MV External Radiotherapy Procedures Using Gel Dosimetry and Monte Carlo Method

    PubMed Central

    Khosravi, H.; Hashemi, B.; Mahdavi, S. R.; Hejazi, P.

    2015-01-01

    Background Gel polymers are considered as new dosimeters for determining radiotherapy dose distribution in three dimensions. Objective The ability of a new formulation of MAGIC-f polymer gel was assessed by experimental measurement and Monte Carlo (MC) method for studying the effect of gold nanoparticles (GNPs) in prostate dose distributions under the internal Ir-192 and external 18MV radiotherapy practices. Method A Plexiglas phantom was made representing human pelvis. The GNP shaving 15 nm in diameter and 0.1 mM concentration were synthesized using chemical reduction method. Then, a new formulation of MAGIC-f gel was synthesized. The fabricated gel was poured in the tubes located at the prostate (with and without the GNPs) and bladder locations of the phantom. The phantom was irradiated to an Ir-192 source and 18 MV beam of a Varian linac separately based on common radiotherapy procedures used for prostate cancer. After 24 hours, the irradiated gels were read using a Siemens 1.5 Tesla MRI scanner. The absolute doses at the reference points and isodose curves resulted from the experimental measurement of the gels and MC simulations following the internal and external radiotherapy practices were compared. Results The mean absorbed doses measured with the gel in the presence of the GNPs in prostate were 15% and 8 % higher than the corresponding values without the GNPs under the internal and external radiation therapies, respectively. MC simulations also indicated a dose increase of 14 % and 7 % due to presence of the GNPs, for the same experimental internal and external radiotherapy practices, respectively. Conclusion There was a good agreement between the dose enhancement factors (DEFs) estimated with MC simulations and experiment gel measurements due to the GNPs. The results indicated that the polymer gel dosimetry method as developed and used in this study, can be recommended as a reliable method for investigating the DEF of GNPs in internal and external

  2. 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)

  3. Measurement of residual 60Co activity induced by atomic-bomb neutrons in Nagasaki and background contribution by environmental neutrons.

    PubMed

    Shizuma, Kiyoshi; Endo, Satoru; Hoshi, Masaharu; Takada, Jun; Iwatani, Kazuo; Hasai, Hiromi; Oka, Takamitsu; Shimazaki, Tatsuya; Okumura, Yutaka; Fujita, Shoichiro; Watanabe, Tadaaki; Imanaka, Tetsuji

    2002-12-01

    Residual 60Co activity in five steel samples induced by neutrons from the Nagasaki atomic bomb has been measured within about 1000 m from the hypocenter. The chemical separation of cobalt and nickel from steel samples was performed, and cobalt-enriched samples were prepared for all samples. Gamma-ray measurements were carried out with a low-background well-type germanium detector. The gamma-ray spectra for five samples were compared with the spectrum of a control sample to ensure that the observed 60Co was actually induced by A-bomb neutrons. The activation of cobalt by environmental neutrons was also investigated. It has been shown that the present 60Co data are consistent with earlier Hashizume's data. PMID:12674203

  4. Migration of radioactive {sup 85}Sr, {sup 134}Cs and {sup 60}Co through a loess soil layer

    SciTech Connect

    Li, Z.; Wang, H.; Takebe, Shinichi; Tanaka, Tadao

    1995-12-31

    Column experiments have been completed on the migration of {sup 85}Sr, {sup 134}Cs and {sup 60}Co through a loess layer in order to examine the migration behavior of radionuclides in an aerated soil layer. Radionuclide concentration distributions between the effluent and the soil layer were measured after the solution containing the radionuclides was introduced into the column from the top of the soil layer and fifty liters of the underground water were introduced at a constant flow. Results indicate most of the {sup 85}Sr, {sup 134}Cs and {sup 60}Co remained attached to the soil layer, and only a small amount of radionuclide was released from the soil layer. Within the soil layer, the migration depths of three radionuclides are {sup 85}Sr > {sup 134}Cs = {sup 60}Co.

  5. 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

  6. Succinylcholine-induced hyperkalemia in the rat following radiation injury to muscle. [60Co

    SciTech Connect

    Cairoli, V.J.; Ivankovich, A.D.; Vucicevic, D.; Patel, K.

    1982-02-01

    During anesthetic preparation of a patient who had received routine radiation therapy of sarcoma of the leg, cardiac collapse occurred following succinylcholine (SCh) administration. Experiments were designed to test the hypothesis that radiation injury to muscle might cause increased sensitivity to SCh similar to that reported in patients with muscle trauma, severe burns, and lesions causing muscle denervation. Venous plasma potassium levels and arterial blood gas tensions were measured in rats after they were given SCh (3 mg/kg) at various times following 60Co irradiation of the hind legs. Nonirradiated rats responded to SCh with a slight but statistically significant increase in plasma K+. Rats subjected to high levels of radiation (10,000 to 20,000 R) and given SCh 4 to 7 days later responded in the same way as the control rats. Plasma K+ levels in rats exposed to a fractionated irradiated dosage (25000 R given twice with a 1-week interval) followed by SCh 1 week later were similar to those in the control group, but when SCh was given 2 weeks later (3 weeks after initial irradiation) there was a marked elevation of plasma K+, from 3.6 to 7.7 meq/L, a statistically significant increase.

  7. Studying the Effect of Ionization Radiation of 60Co on the Spirulina

    NASA Astrophysics Data System (ADS)

    Ai, Weidang; Guo, Shuang-Sheng; Ai, Weidang; Dong, Wen-Ping; Qin, Li-Feng; Tang, Yong-Kang

    It studied the effect of ionization radiation on the Spirulina plastensis(No.6) by using the γ-rays of 60 Co. In the experiment, Spirulina were irradiated, and the dose of the ionization radiation covered 0, 0.5, 1.0, 1.5, 2.0, 2.5, 3.0kGy. After irradiating, these Spirulina were cultured under the same conditions. During the course of the experiment, the growth rate, photosynthetic efficiency and nutrition quality of the Spirulina, were analyzed. From the results, low dose of γ-rays (less than 1.5kGy) could improve the content of phycobilin and protein of Spirulina. Only small changes in the morphology of algae filament were found at dose less than 1.0kGy. But with the increase of the dose of γ-rays (more than 1.5kGy), the filaments would break up or even disintegrate. Spirulina had stronger ionization radiation proof and self-rehabilitation capacity, but the growth of Spirulina was stagnated. The LD50 (i.e. the dose resulted in 50% death of the Spirulina) of the colony was 2.0kGy. Considering the capacity of being resistant to γ-rays irradiation, Spirulina can be considered as one of the key biological components in the Controlled Ecological Life Support System (CELSS) for future long-term space missions. Keywords: Controlled Ecological Life Support System (CELSS); Spirulina; ionization radiation; biological component

  8. The effect of perinatal sup 60 Co gamma radiation on brain weight in beagles

    SciTech Connect

    Hamilton, B.F.; Benjamin, S.A.; Angleton, G.M.; Lee, A.C. )

    1989-08-01

    Beagle dogs were given single, whole-body {sup 60}Co gamma-radiation exposures at one of three prenatal (8, 28, or 55 days postcoitus) or three postnatal (2, 70, or 365 days postpartum) ages to evaluate the relative radiosensitivity of various stages of brain development. A total of 387 dogs received mean doses ranging from 0.16 to 3.83 Gy, and 120 dogs were sham-irradiated. Groups of dogs were sacrificed at preselected times from 70 days to 11 years of age. Brain weight decreased significantly with increasing dose in dogs irradiated at 28 or 55 days postcoitus or at 2 days postpartum. Irradiations at 28 days postcoitus were dramatically more effective in causing a reduction in brain weight than those at 55 days postcoitus or 2 days postpartum. Among dogs given 1.0 Gy or more and followed for up to 4 years, there was a radiation effect evident at all three sensitive exposure ages. Among dogs given lower doses and followed for up to 11 years, there was a significant decrease in brain weight in dogs given 0.80-0.88 Gy at 28 days postcoitus. All decreases in brain weight were present after normalization for radiation-induced reductions in skeletal (body) size. No specific morphologic changes were noted in the brains which showed the radiation-related reductions in size.

  9. Level densities and spin cutoff parameters for 60Co and 62Ni from proton evaporation spectra

    NASA Astrophysics Data System (ADS)

    Voinov, Alexander; Grimes, Steven; Brune, Carl R.; Burger, Alexander; Gorgen, Andreas; Guttormsen, Magne; Larsen, Ann Cecilie; Massey, Tomas; Siem, Sunniva

    2013-10-01

    Prediction of reaction cross sections remains a major problem in applications such as data evaluations or/and astrophysics reaction rate calculations. There is big progress in the development of nuclear reaction codes which now include different reaction mechanisms. However, these codes use many input parameters. The variety of input parameters helps us to describe existing experimental data but it creates problems when it comes to predictions. The uncertainties of the level density and the spin cutoff parameter cause the major concern. The proton spectra from α and lithium induced reactions have been measured and analyzed with the Hauser-Feshbach model. Different input level density models have been tested. The level densities and spin cutoff parameters were obtained with Monte-Carlo technique taking into account known spins of discrete low-lying levels of residual nuclei. It was found that the best description is achieved with the Gilbert and Cameron model functions. Excitation energy dependence of spin cutoff parameters was found to be different for 60Co and 62Ni nuclei. It is inconsistent with Fermi-gas model which is usually used to calculate spin cutoff parameters.

  10. Estimation of the radiation field homogeneity in 60Co blood irradiator

    NASA Astrophysics Data System (ADS)

    Urban, Tomas

    2014-11-01

    The aim of this work is to estimate the homogeneity of the radiation field in various configurations and relative activities of the “disposed” but still relatively highly active (approximately thousands of Curies, i.e. tens of TBq) sources for their potential use in irradiation of blood (or blood derivatives). Small dose rate, which is already unusable/inappropriate for the teletherapy, may be still utilized by simultaneous use of multiple sources or reducing the distance to the irradiated object (blood unit). To estimate the homogeneity of the radiation field a modeling approach has been chosen in which Monte Carlo code MCNP has been employed. (In-) homogeneity of the radiation field has been estimated on the basis of isodoses in the water phantom and for various configurations and relative activities of the 60Co sources. The results of simulations are also discussed with regard to further optimization (homogeneity of the sample irradiation, costs, radiation protection of service staff, availability of a sufficient number of resources, etc.).

  11. Comparison of the Absorbed Dose for 99mTc-Diethylenetriaminepentaacetic Acid and 99mTc-Ethylenedicysteine Radiopharmaceuticals using Medical Internal Radiation Dosimetry

    PubMed Central

    Pirdamooie, Shokufeh; Shanei, Ahmad; Moslehi, Masoud

    2015-01-01

    The aim of this study was the investigation of absorbed dose to the kidneys, spleen, and liver during technetium-99 m ethylene dicysteine and technetium-99 m diethylenetriaminepentaacetic acid (99mTc-EC and 99mTc-DTPA) kidney scan. Patients who had been prepared for the kidney scan, were divided into two groups (Groups 1 and 2). The first group (Group 1) and the second group (Group 2) received intravenous injection of 99mTc-EC and 99mTc-DTP, respectively. A certain amount of radiopharmaceuticals was injected into each patient and was immediately imaged with dual-head gamma camera to calculate the activity through the conjugated view method. Then, the doses of kidney, liver, and spleen were measured using medical internal radiation dosimetry method. Finally, absorbed dose of these organs was compared. Based on these different results (P < 0.05), organs absorbed dose was significantly less with radiopharmaceutical 99mTc-EC as compared with 99mTc-DTPA. PMID:26284173

  12. Dosimetry of [177Lu]-DO3A-VS-Cys40-Exendin-4 – impact on the feasibility of insulinoma internal radiotherapy

    PubMed Central

    Velikyan, Irina; Bulenga, Thomas N; Selvaraju, Ramkumar; Lubberink, Mark; Espes, Daniel; Rosenström, Ulrika; Eriksson, Olof

    2015-01-01

    [68Ga]-DO3A-VS-Cys40-Exendin-4 has been shown to be a promising imaging candidate for targeting glucagon like peptide-1 receptor (GLP-1R). In the light of radiotheranostics and personalized medicine the 177Lu-labelled analogue is of paramount interest. In this study we have investigated the organ distribution of [177Lu]-DO3A-VS-Cys40-Exendin-4 in rat and calculated human dosimetry parameters in order to estimate the maximal acceptable administered radioactivity, and thus potential applicability of [177Lu]-DO3A-VS-Cys40-Exendin-4 for internal radiotherapy of insulinomas. Nine male and nine female Lewis rats were injected with [177Lu]-DO3A-VS-Cys40-Exendin-4 for ex vivo organ distribution study at nine time points. The estimation of human organ/total body absorbed and total effective doses was performed using Organ Level Internal Dose Assessment Code software (OLINDA/EXM 1.1). Six more rats (male: n = 3; female: n = 3) were scanned by single photon emission tomography and computed tomography (SPECT-CT). The renal function and potential cell dysfunction were monitored by creatinine ISTAT and glucose levels. The fine uptake structure of kidney and pancreas was investigated by ex vivo autoradiography. Blood clearance and washout from most of the organs was fast. The kidney was the dose-limiting organ with absorbed dose of 5.88 and 6.04 mGy/MBq, respectively for female and male. Pancreatic beta cells demonstrated radioactivity accumulation. Renal function and beta cell function remained unaffected by radiation. The absorbed dose of [177Lu]-DO3A-VS-Cys40-Exendin-4 to kidneys may limit the clinical application of the agent. However, hypothetically, kidney protection and peptidase inhibition may allow reduction of kidney absorbed dose and amplification of tumour absorbed doses. PMID:25973333

  13. The In-Vitro Transport of (238)PLUTONIUM Oxide and (239)PLUTONIUM Oxide Through a Membrane Filter and its Importance for Internal Radiation Dosimetry.

    NASA Astrophysics Data System (ADS)

    Ryan, Michael Terrance

    These experiments were designed to determine if ('238)PuO(,2), due to its higher specific activity and attendant aggregate recoil, undergoes higher transfer through a membrane filter into an interstitial human alveolar lung fluid simulant than ('239)PuO(,2). The rate at which such transfer occurs was determined in an in-vitro chamber designed to simulate residence characteristics of particles of insoluble plutonium oxides in human alveolar interstitium. The ratio of the rate of ('238)Pu/('239)Pu transfer was 138 (+OR -) 76%. Calculations were performed to assess the importance of this finding in terms of the internal dosimetry of insoluble ('238)Pu using methods and models recommended by the International Commission on Radiological Protection. Three cases were evaluated, namely integral 50-year dose commitment, urinary excretion after single acute intake and urinary excretion rate during chronic constant intake. It was found that integral 50-year dose commitments were not influenced by the rate of plutonium transfer from the pulmonary compartment to blood. The evaluation of calculated urinary excretion data after a single acute inhalation intake showed that in the early period, up to about 30 days post exposure, urinary excretion of ('238)PuO(,2) may be 2 to 10 times higher than the urinary excretion rate for ('238)PuO(,2) predicted by the ICRP reference model. From about 50 days to approximately 1000 days the calculated urinary excretion rate for ('238)PuO(,2) may be lower than that predicted by the reference model by a factor of 2 to 10. In the case of chronic constant intake the calculated urinary excretion rate for ('238)PuO(,2) may be up to a factor of 2 higher than that predicted by the reference ICRP Model.

  14. Proposed model for estimating dose to inhabitants of 60Co contaminated buildings.

    PubMed

    Cardarelli, J; Elliott, L; Hornung, R; Chang, W P

    1997-03-01

    A model to predict the time weighted exposures to gamma radiation was developed for buildings constructed with structural steel having some contamination from 60Co. Several buildings throughout sixteen city blocks in downtown Taipei were built about ten years ago with this material. These buildings were used for residential, business, and educational purposes with radiation levels ranging from background to five hundred times background. A comprehensive epidemiologic study by the National Yang Ming University Medical School in Taipei is underway to study the effects of this exposure to the building occupants. An evaluation of external radiation exposure was performed using survey instruments and thermoluminescent dosimeters. Exposure data from the survey instruments were used in a computer model developed to calculate cumulative radiation exposure estimates for the epidemiologic research. While the survey instrument data provided radiation levels at a point in time, the thermoluminescent dosimeters were placed in fixed locations and on several volunteers for a period of one month to verify the modeling results. The model itself is a mathematical algorithm that provides estimates with minimum and maximum range values by taking into account differences in the survey data between adults and children, variable occupancy patterns, background radiation, and radioactive decay. Several assumptions (background rates, height adjustment values, and occupancy factors) are easily adjusted to improve the estimated radiation exposures. The model predicted the exposures as measured by the thermoluminescent dosimeters with greater reliability for adults than for children. The differences between the two methods were about 10-15% for the adults and about 60% for the child. This strategy, its advantages, limitations, and its performance against actual thermoluminescent dosimeter measurements are presented. PMID:9030836

  15. Key comparison BIPM.RI(I)-K1 of the air-kerma standards of the NIM, China and the BIPM in 60Co gamma radiation

    NASA Astrophysics Data System (ADS)

    Kessler, C.; Burns, D.; Wang, K.; Fan, Y.; Jin, S.; Yang, X.

    2016-01-01

    An indirect comparison of the standards for air kerma of the National Institute of Metrology (NIM), China and of the Bureau International des Poids et Mesures (BIPM) was carried out in the 60Co radiation beam of the BIPM in November 2015. The comparison result, evaluated as a ratio of the NIM and the BIPM standards for air kerma, is 0.9997 with a combined standard uncertainty of 2.7 × 10-3. The results are analysed and presented in terms of degrees of equivalence for entry in the BIPM key comparison database. Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCRI, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

  16. [Secondary Standard Dosimetry Laboratory at the Ruder Bosković Institute, Zagreb].

    PubMed

    Vekić, Branko; Ban, Renata; Miljanić, Saveta

    2006-06-01

    The Secondary Standard Dosimetry Laboratory at the Ruder Bosković Institute (SSDL), Zagreb, Croatia, was set up over the last few years with a strong support by the International Atomic Energy Agency (IAEA) through the Technical Cooperation Project CRO/1/004, Establishing Calibration Services. The SSDL occupies two calibration rooms, each 9.6 m long and 6 m wide and each with proper air conditioning. Their walls are concrete and 1 m thick, and the entrance doors are plated with lead to protect the control rooms and the surroundings against radiation. In the first calibration room in the basement, there are two sealed sources which share the same, 6 m long calibration bench. A 30 TBq 60Co source on one side of the bench is used for calibrating ionising chambers and other high-dose radiation equipment. The irradiation unit on the other side of the bench combines two sealed sources, that is, a 740 MBq 137Cs source and a 185 MBq 60Co source, and is used for radiation protection purposes. It has three attenuators with nominal attenuations of x10, x100, and x1000. The second calibration room, which is just above the first, accommodates an X-ray unit (ISOVOLT 420, 40 kV to 300 kV, 1 mA to 20 mA) with a 5 m long calibration bench, aperture wheel assembly designed to modify the X-ray beam diameter to meet various configuration requirements for calibration instruments, a set of filter assemblies to control beam definition according to ISO 4037-3, and a half-value layer kit. PMID:16832975

  17. Proficiency Testing as a tool to monitor consistency of measurements in the IAEA/WHO Network of Secondary Standards Dosimetry Laboratories

    NASA Astrophysics Data System (ADS)

    Meghzifene, Ahmed; Czap, Ladislav; Shortt, Ken

    2008-08-01

    The International Atomic Energy Agency (IAEA) and the World Health Organization (WHO) established a Network of Secondary Standards Dosimetry Laboratories (IAEA/WHO SSDL Network) in 1976. Through SSDLs designated by Member States, the Network provides a direct link of national dosimetry standards to the international measurement system of standards traceable to the Bureau International des Poids et Mesures (BIPM). Within this structure and through the proper calibration of field instruments, the SSDLs disseminate S.I. quantities and units. To ensure that the services provided by SSDL members to end-users follow internationally accepted standards, the IAEA has set up two different comparison programmes. One programme relies on the IAEA/WHO postal TLD service and the other uses comparisons of calibrated ionization chambers to help the SSDLs verify the integrity of their national standards and the procedures used for the transfer of the standards to the end-users. The IAEA comparisons include 60Co air kerma (NK) and absorbed dose to water (ND,W) coefficients. The results of the comparisons are confidential and are communicated only to the participants. This is to encourage participation of the laboratories and their full cooperation in the reconciliation of any discrepancy. This work describes the results of the IAEA programme comparing calibration coefficients for radiotherapy dosimetry, using ionization chambers. In this programme, ionization chambers that belong to the SSDLs are calibrated sequentially at the SSDL, at the IAEA, and again at the SSDL. As part of its own quality assurance programme, the IAEA has participated in several regional comparisons organized by Regional Metrology Organizations. The results of the IAEA comparison programme show that the majority of SSDLs are capable of providing calibrations that fall inside the acceptance level of 1.5% compared to the IAEA.

  18. Dosimetric considerations of symmetric and asymmetric 60Co teletherapy split fields.

    PubMed

    Wrede, D E; Givens, S B

    1977-01-01

    Split fields are commonly used for a variety of treatments for which local shielding is desired; a single field is split into two fields by means of lead blocks placed in the beam. The condition for assuming independence of the two fields is investigated by using the area over perimeter calculational method and comparing this to experimental depth-dose data measured in a water phantom using a Shonka ionization chamber. Two principal variations affecting dose distributions are examined: block width and position of the block expressed as the fractional perpendicular distance between the central ray of the overall field and the center of the block. An intercomparison between calculation and experimental data shows that the right and left sides of the split field behave as independent fields giving TAR values in agreement with experimental data to within +/-1%. If the fields are asymmetric and if the larger field is less than 70% of the total area including the blocked part, then the dosimetry should be based on average TARs, off-center ratios, and backscatter factors for the two fields. If the larger area is greater than 70% of the total area, then the treatment time can be calculated from the larger field only. PMID:904593

  19. Fast timing study of a CeBr3 crystal: Time resolution below 120 ps at 60Co energies

    NASA Astrophysics Data System (ADS)

    Fraile, L. M.; Mach, H.; Vedia, V.; Olaizola, B.; Paziy, V.; Picado, E.; Udías, J. M.

    2013-02-01

    We report on the time response of a novel inorganic scintillator, CeBr3. The measurements were performed using a cylindrical crystal of 1-in. in height and 1-in. in diameter at 22Na and 60Co photon energies. The time response was measured against a fast reference BaF2 detector. Hamamatsu R9779 and Photonis XP20D0 fast photomultipliers (PMTs) were used. The PMT bias voltages and Constant Fraction Discriminator settings were optimized with respect to the timing resolution. The Full Width at Half Maximum (FWHM) time resolution for an individual CeBr3 crystal coupled to Hamamatsu PMT is found here to be as low as 119 ps at 60Co energies, which is comparable to the resolution of 107 ps reported for LaBr3(Ce). For 511 keV photons the measured FWHM time resolution for CeBr3 coupled to the Hamamatsu PMT is 164 ps.

  20. The treatment of solid tumors by alpha emitters released from 224Ra-loaded sources—internal dosimetry analysis

    NASA Astrophysics Data System (ADS)

    Arazi, L.; Cooks, T.; Schmidt, M.; Keisari, Y.; Kelson, I.

    2010-02-01

    Diffusing alpha-emitters radiation therapy (DART) is a proposed new form of brachytherapy, allowing the treatment of solid tumors by alpha particles. DART utilizes implantable sources carrying small activities of radium-224, which continually release into the tumor radon-220, polonium-216 and lead-212 atoms, while radium-224 itself remains fixed to the source. The released atoms disperse inside the tumor by diffusive and convective processes, creating, through their alpha emissions, a high-dose region measuring several mm in diameter about each source. The efficacy of DART has been demonstrated in preclinical studies on mice-borne squamous cell carcinoma and lung tumors and the method is now being developed toward clinical trials. This work studies DART safety with respect to the dose delivered to distant organs as a result of lead-212 leakage from the tumor through the blood, relying on a biokinetic calculation coupled to internal dose assessments. It is found that the dose-limiting organs are the kidneys and red bone marrow. Assuming a typical source spacing of ~5 mm and a typical radium-224 activity density of 0.4-0.8 MBq g-1 of tumor tissue, it is predicted that tumors weighing up to several hundred grams may be treated without reaching the tolerance dose in any organ.

  1. Accumulation of radioactive corrosion products on steel surfaces of VVER-type nuclear reactors. II. 60Co

    NASA Astrophysics Data System (ADS)

    Varga, Kálmán; Hirschberg, Gábor; Németh, Zoltán; Myburg, Gerrit; Schunk, János; Tilky, Péter

    2001-10-01

    In the case of intact fuel claddings, the predominant source of radioactivity in the primary circuits of water-cooled nuclear reactors is the activation of corrosion products in the core. The most important corrosion product radionuclides in the primary coolant of pressurized water reactors (PWRs) are 60Co, 58Co, 51Cr, 54Mn, 59Fe (as well as 110mAg in some Soviet-made VVER-type reactor). The second part of this series is focused on the complex studies of the formation and build-up of 60Co-containing species on an austenitic stainless steel type 08X18H10T (GOST 5632-61) and magnetite-covered carbon steel often to be used in Soviet-planned VVERs. The kinetics and mechanism of the cobalt accumulation were studied by a combination (coupling) of an in situ radiotracer method and voltammetry in a model solution of the primary circuit coolant. In addition, independent techniques such as X-ray photoelectron spectroscopic (XPS) and ICP-OES are also used to analyze the chemical state of Co species in the passive layer formed on stainless steel as well as the chemical composition of model solution. The experimental results have revealed that: (i) The passive behavior of the austenitic stainless steel at open-circuit conditions, the slightly alkaline pH and the reducing water chemistry can be considered to be optimal to minimize the 60Co contamination. (ii) The highly potential dependent deposition of various Co-oxides at E>1.10 V (vs. RHE) offers a unique possibility to elaborate a novel electrochemical method for the decrease or removal of cobalt traces from borate-containing coolants contaminated with 60Co and/or 58Co radionuclides.

  2. Grafting of synthetic polyelectrolyte onto polymer surfaces--comparison of glow discharge and sup 60 Co-gamma-irradiation method

    SciTech Connect

    Hari, P.R.; Sharma, C.P. )

    1990-07-01

    Water soluble polyelectrolyte synthesized from natural rubber contains sulfamate and carboxylate groups similar to that of heparin. It is observed that synthetic heparinoid polyelectrolyte is capable of inhibiting blood coagulation. In the present study, we attempted to graft the same onto polystyrene and polymethylmethacrylate surfaces using glow discharge technique and {sup 60}Co-gamma-irradiation method, and the surfaces were compared with respect to water contact angle and platelet adhesion parameters. Heparinized surfaces are also evaluated for relative comparison.

  3. Combined reactor neutron beam and {sup 60}Co γ-ray radiation effects on CMOS APS image sensors

    SciTech Connect

    Wang, Zujun Chen, Wei; Sheng, Jiangkun; Liu, Yan; Xiao, Zhigang; Huang, Shaoyan; Liu, Minbo

    2015-02-15

    The combined reactor neutron beam and {sup 60}Co γ-ray radiation effects on complementary metal-oxide semiconductor (CMOS) active pixel sensors (APS) have been discussed and some new experimental phenomena are presented. The samples are manufactured in the standard 0.35-μm CMOS technology. Two samples were first exposed to {sup 60}Co γ-rays up to the total ionizing dose (TID) level of 200 krad(Si) at the dose rates of 50.0 and 0.2 rad(Si)/s, and then exposed to neutron fluence up to 1 × 10{sup 11} n/cm{sup 2} (1-MeV equivalent neutron fluence). One sample was first exposed to neutron fluence up to 1 × 10{sup 11} n/cm{sup 2} (1-MeV equivalent neutron fluence), and then exposed to {sup 60}Co γ-rays up to the TID level of 200 krad(Si) at the dose rate of 0.2 rad(Si)/s. The mean dark signal (K{sub D}), the dark signal non-uniformity (DSNU), and the noise (V{sub N}) versus the total dose and neutron fluence has been investigated. The degradation mechanisms of CMOS APS image sensors have been analyzed, especially for the interaction induced by neutron displacement damage and TID damage.

  4. Cytogenetic comparison of the responses of mouse and human peripheral blood lymphocytes to /sup 60/Co gamma radiation

    SciTech Connect

    Kligerman, A.D.; Halperin, E.C.; Erexson, G.L.; Honore, G.; Westbrook-Collins, B.; Allen, J.W.

    1988-08-01

    Experiments were conducted to compare the chromosome damaging effects of /sup 60/Co gamma radiation on mouse and human peripheral blood lymphocytes (PBLs). Either whole blood or isolated and pelleted mononuclear leucocytes (MNLs) were irradiated with a /sup 60/Co unit to yield exposures of 1, 2, 3, or 4 Gy. In addition, mice were whole-body irradiated in vivo with the same doses so that an in vitro-in vivo comparison could be made. The results indicate that mouse PBLs irradiated in whole blood, whether in vivo or in vitro, respond similarly to /sup 60/Co gamma rays as measured by dicentric chromosome formation. In addition, mouse and human PBLs showed a similar radiosensitivity, but because the mouse PBL data were best fitted to an exponential function and the human PBL data to a quadratic function, direct comparisons were difficult to make. Pelleted MNLs from mice were much less sensitive to the clastogenic effects of gamma radiation than whole blood. This is believed to be due to hypoxic conditions that developed during irradiation and transport. Human PBLs did not show a marked difference whether irradiated in whole blood or as pelleted MNLs in tissue culture medium.

  5. 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)

  6. Steroid hormone production in testis, ovary, and adrenal gland of immature rats irradiated in utero with /sup 60/Co

    SciTech Connect

    Inano, H.; Suzuki, K.; Ishii-Ohba, H.; Imada, Y.; Kumagai, R.; Kurihara, S.; Sato, A.

    1989-02-01

    Pregnant rats received whole-body irradiation at 20 days of gestation with 2.6 Gy lambda rays from a 60Co source. Endocrinological effects before maturation were studied using testes and adrenal glands obtained from male offspring and ovaries from female offspring irradiated in utero. Seminiferous tubules of the irradiated male offspring were remarkably atrophied with free germinal epithelium and containing only Sertoli cells. Female offspring also had atrophied ovaries. Testicular tissue obtained from intact and 60Co-irradiated rats was incubated with 14C-labeled pregnenolone, progesterone, 17 alpha-hydroxyprogesterone, and androstenedione as a substrate. Intermediates for androgen production and catabolic metabolites were isolated after the incubation. The amounts of these metabolites produced by the irradiated testes were low in comparison with the control. The activities of delta 5-3 beta-hydroxysteroid dehydrogenase, 17 alpha-hydroxylase, C17,20-lyase, and delta 4-5 alpha-reductase in the irradiated testes were 30-40% of those in nonirradiated testes. Also, the activities of 17 beta- and 20 alpha-hydroxysteroid dehydrogenases were 72 and 52% of the control, respectively. In adrenal glands, the 21-hydroxylase activity of the irradiated animals was 38% of the control, but the delta 5-3 beta-hydroxysteroid dehydrogenase activity was comparable to that of the control. On the other hand, the activity of delta 5-3 beta-hydroxysteroid dehydrogenase of the irradiated ovary was only 19% of the control. These results suggest that 60Co irradiation of the fetus in utero markedly affects the production of steroid hormones in testes, ovaries, and adrenal glands after birth.

  7. Transfer of 137Cs and 60Co in a waste retention pond with emphasis on aquatic insects

    SciTech Connect

    Voshell, J.R. Jr.; Eldridge, J.S.; Oakes, T.W.

    1985-11-01

    The objectives of this research were (1) to analyze the transfers of 137Cs and 60Co in a retention pond, with emphasis on aquatic insects and (2) to determine if detectable concentrations of these radionuclides are exported by emerging aquatic insects. We analyzed the radionuclide concentrations in the following components: water solution, bottom sediments, suspended particulate matter, plankton, floating mats of filamentous algae, benthic macroinvertebrates, and emerging aquatic insects. Samples were collected quarterly from June 1981 to April 1982. The lowest concentrations (in picocuries per milliliter) occurred in solution (range: 1.4 X 10(2) to 3.2 X 10(2) for 137Cs and 8.1 X 10(-1) to 2.2 X 10(0) for 60Co). The highest concentrations (in picocuries per gram dry weight) occurred in the sediments (range: 1.5 X 10(4) to 1.1 X 10(8) for 137Cs and 1.0 X 10(2) to 4.3 X 10(6) for 60Co). The primary producers and aquatic insect consumers had concentrations of both radionuclides that were two to four orders of magnitude higher than the respective concentrations dissolved in water but two to three orders of magnitude lower than the concentrations in the sediments. The concentrations of both radionuclides decreased successively at higher trophic levels. There were considerable temporal variations as the radionuclides cycled among the abiotic and biotic components of the pond. Emerging adult aquatic insects had lower concentrations of both radionuclides than the immature stages that lived in the pond (adult/immature ratio about 0.25). Because the emerging adult insects contain detectable concentrations of radionuclides, have relatively long life spans, and disperse away from the aquatic habitat, we conclude that adult aquatic insects would be effective biological monitors.

  8. Radiotherapy of bronchogenic carcinoma: analysis of a treatment schedule designed for use with hyperbaric oxygen. [/sup 60/Co

    SciTech Connect

    Sause, W.T.; Sweeney, R.A.; Plenk, H.P.; Thomson, J.W.

    1981-07-01

    All cases of bronchogenic carcinoma treated with curative intent over an eight-year period were reviewed. Most were treated with 12 x 400 rad in 32 days using /sup 60/Co, a schedule designed to optimize the radiation-sensitizing properties of hyperbaric oxygen. While O/sub 2/ gave no obvious benefit, overall four-year survival was 10.6% and that of patients with good prognostic indicators was 18%. No radiation myelitis was observed. This protocol delivers an adequate tumor dose and appears to be tolerated well by most patients.

  9. 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.

  10. Final report on APMP.RI(I)-K1: APMP/TCRI key comparison report of measurement of air kerma for 60Co gamma-rays

    NASA Astrophysics Data System (ADS)

    Chun, K. J.; Butler, D. J.; Webb, D.; Mahant, A. K.; Meghzifene, A.; Lee, J. H.; Hah, S. H.; Kadni, T. B.; Zhang, Y.; Kurosawa, T.; Msimang, Z. L. M.; Caseria, E. S.

    2013-01-01

    The APMP.RI(I)-K1 key comparison of the measurement standards of air kerma for 60Co gamma-rays was undertaken by the APMP/TCRI Dosimetry Working Group between 2004 and 2006, coordinated by the Korean Research Institute of Standards and Science (KRISS). In total, 10 institutes took part in the comparison, among which 7 were APMP member laboratories. Three Farmer-type commercial cavity chambers were used as transfer chambers and circulated among the participants. All the participants carried out their measurements according to the guidelines for the comparison established by the KRISS with the cooperation of the ARPANSA. For each transfer chamber, an NMI calibration coefficient was obtained and a ratio derived by dividing by the average result from the linking laboratories, ARPANSA and NMIJ. The APMP comparison reference value for each chamber was calculated as the mean of the NMI-determined calibration coefficients divided by the average result from the linking laboratories. The results showed that the maximum difference between the APMP linked ratio of a participating NMI and the APMP reference value was 1.76%. The measured ratios of the calibration coefficient RNMI, BIPM between the participating NMI and the BIPM via the link laboratories for the transfer chambers were obtained. The maximum expanded uncertainty of RNMI, BIPM for any participating laboratory was 2.0%. The degree of equivalence of each participating laboratory with respect to the key comparison reference value was also evaluated. The expanded uncertainty of the difference between the results ranged from 0.5% to 1.2%. The pair-wise degree of equivalence between each pair of laboratories was also obtained and the largest difference of the expanded uncertainty of the difference for any pair-wise degree of equivalence was within the expanded uncertainty of the measurement for the pair of laboratories. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that

  11. WE-E-BRE-01: An Image-Based Skeletal Dosimetry Model for the ICRP Reference Adult Female - Internal Electron Sources

    SciTech Connect

    O'Reilly, S; Maynard, M; Marshall, E; Bolch, W; Sinclair, L; Rajon, D; Wayson, M

    2014-06-15

    Purpose: Limitations seen in previous skeletal dosimetry models, which are still employed in commonly used software today, include the lack of consideration of electron escape and cross-fire from cortical bone, the modeling of infinite spongiosa, the disregard of the effect of varying cellularity on active marrow self-irradiation, and the lack of use of the more recent ICRP definition of a 50 micron surrogate tissue region for the osteoprogenitor cells - shallow marrow. These limitations were addressed in the present dosimetry model. Methods: Electron transport was completed to determine specific absorbed fractions to active marrow and shallow marrow of the skeletal regions of the adult female. The bone macrostructure was obtained from the whole-body hybrid computational phantom of the UF series of reference phantoms, while the bone microstructure was derived from microCT images of skeletal region samples taken from a 45 year-old female cadaver. The target tissue regions were active marrow and shallow marrow. The source tissues were active marrow, inactive marrow, trabecular bone volume, trabecular bone surfaces, cortical bone volume and cortical bone surfaces. The marrow cellularity was varied from 10 to 100 percent for active marrow self-irradiation. A total of 33 discrete electron energies, ranging from 1 keV to 10 MeV, were either simulated or modeled analytically. Results: The method of combining macro- and microstructure absorbed fractions calculated using MCNPX electron transport was found to yield results similar to those determined with the PIRT model for the UF adult male in the Hough et al. study. Conclusion: The calculated skeletal averaged absorbed fractions for each source-target combination were found to follow similar trends of more recent dosimetry models (image-based models) and did not follow current models used in nuclear medicine dosimetry at high energies (due to that models use of an infinite expanse of trabecular spongiosa)

  12. 60Co-irradiation as an alternate method for sterilization of penicillin G, neomycin, novobiocin, and dihydrostreptomycin

    SciTech Connect

    Tsuji, K.; Rahn, P.D.; Steindler, K.A.

    1983-01-01

    The effects of the use of 60Co-irradiation to sterilize antibiotics were evaluated. The antibiotic powders were only occasionally contaminated with microorganisms. The D-values of the products and environmental isolates were 0.028, 0.027, 0.015, 0.046, 0.15, 0.018, and 0.19 Mrads for Aspergillus species (UC 7297, 7298), A. fumigatus (UC 7299), Rhodotorula species (UC 7300), Penicillium oxalicum (UC 7269), Pseudomonas maltophilia (UC 6855), and a biological indicator microorganism, Bacillus pumilus spores (ATCC 27142). An irradiation dose of 1.14 Mrads, therefore, was sufficient to achieve a six-log cycle destruction of B. pumilus spores. Based on the bioburden data, a minimum irradiation dose of 1.05 Mrads was calculated to be sufficient to obtain a 10(-6) probability of sterilizing the most radioresistant isolate, Pen. oxalicum. To determine the radiolytic degradation scheme and the stability of the antibiotics following irradiation, high-performance liquid chromatographic (HPLC) methods were developed. The resulting rates of degradation for the antibiotics were 0.6, 1.2, 2.3, and 0.95%/Mrad for penicillin G, neomycin, novobiocin, and dihydrostreptomycin, respectively. Furthermore, radiolytic degradation pathways for the antibiotics were identified and found to be similar to those commonly encountered when antibiotics are subjected to acidic, basic, hydrolytic, or oxidative treatments. No radiolytic compounds unique to 60Co-irradiation were found.

  13. Effects of high-temperature anneals and {sup 60}Co gamma-ray irradiation on strained silicon on insulator

    SciTech Connect

    Park, K.; Canonico, M.; Celler, G. K.; Seacrist, M.; Chan, J.; Gelpey, J.; Holbert, K. E.; Nakagawa, S.; Tajima, M.; Schroder, D. K.

    2007-10-01

    Strained silicon on insulator was exposed to high-temperature annealing and high-dose {sup 60}Co gamma ({gamma})-ray irradiation to study the tenacity of the bond between the strained Si film and the underlying buried oxide. During the high-temperature anneals, the samples were ramped at a rate of 150 deg. C/s to 850 deg. C then ramped to 1200, 1250, and 1300 deg. C at a rate of approximately 5x10{sup 5} deg. C/s for millisecond duration anneals. For the irradiation experiments, the samples were irradiated with {sup 60}Co {gamma} rays to a dose of 51.5 kGy. All samples were characterized by ultraviolet (UV) Raman, pseudo metal-oxide-semiconductor field-effect transistor ({psi}-MOSFET) current voltage, Hall mobility, and photoluminescence (PL) to verify changes in strain. UV Raman, PL, and {psi}-MOSFET measurements show no strain relaxation for the high-temperature annealed samples and only very slight relaxation for the {gamma}-ray irradiated samples.

  14. Age-specific models for evaluating dose and risk from internal exposures to radionuclides: Report of current work of the Metabolism and Dosimetry Research Group, July 1, 1985-June 30, 1987

    SciTech Connect

    Leggett, R.W.; Warren, B.P.

    1987-09-01

    A projection of the health risk to a population internally exposed to a radionuclide requires explicit or implicit use of demographic, biokinetic, dosimetric, and dose-response models. Exposure guidelines have been based on models for a reference adult with a fixed life span. In this report, we describe recent efforts to develop a comprehensive methodology for estimation of radiogenic risk to individuals and to heterogeneous populations. Emphasis is on age-dependent biokinetics and dosimetry for internal emitters, but consideration also is given to conversion of age-specific doses to estimates of risk using realistic, site-specific demographic models and best available age-specific dose-response functions. We discuss how the methods described here may also improve estimates for the reference adult usually considered in radiation protection. 159 refs.

  15. Comparison of Axxent-Xoft, 192Ir and 60Co high-dose-rate brachytherapy sources for image-guided brachytherapy treatment planning for cervical cancer

    PubMed Central

    Packianathan, S; He, R; Yang, C C

    2015-01-01

    Objective: To evaluate the dosimetric differences and similarities between treatment plans generated with Axxent-Xoft electronic brachytherapy source (Xoft-EBS), 192Ir and 60Co for tandem and ovoids (T&O) applicators. Methods: In this retrospective study, we replanned 10 patients previously treated with 192Ir high-dose-rate brachytherapy. Prescription was 7 Gy × 4 fractions to Point A. For each original plan, we created two additional plans with Xoft-EBS and 60Co. The dose to each organ at risk (OAR) was evaluated in terms of V35% and V50%, the percentage volume receiving 35% and 50% of the prescription dose, respectively, and D2cc, highest dose to a 2 cm3 volume of an OAR. Results: There was no difference between plans generated by 192Ir and 60Co, but the plans generated using Xoft-EBS showed a reduction of up to 50% in V35%, V50% and D2cc. The volumes of the 200% and 150% isodose lines, however, were 74% and 34% greater than the comparable volumes generated with the 192Ir source. Point B dose was on average only 16% of the Point A dose for plans generated with Xoft-EBS compared with 30% for plans generated with 192Ir or 60Co. Conclusion: The Xoft-EBS can potentially replace either 192Ir or 60Co in T&O treatments. Xoft-EBS offers either better sparing of the OARs compared with 192Ir or 60Co or at least similar sparing. Xoft-EBS-generated plans had higher doses within the target volume than 192Ir- or 60Co-generated ones. Advances in knowledge: This work presents newer knowledge in dosimetric comparison between Xoft-EBS, 192Ir or 60Co sources for T&O implants. PMID:25996576

  16. KEY COMPARISON: COOMET.RI(I)-K1 comparison of national measurement standards of air kerma for 60Co γ radiation

    NASA Astrophysics Data System (ADS)

    Büermann, L.; Oborin, A. V.; Dobrovosky, J.; Milevsky, V. S.; Walwyn Salas, G.; Lapenas, A.

    2009-01-01

    Results are presented of the COOMET key comparison of the national measurement standards of air kerma for 60Co γ radiation. Participants of the comparison were PTB (Germany, pilot institute), VNIIM (Russia), SMU (Slovakia), BelGIM (Belarus), CPHR (Cuba) and RMTC (Latvia). PTB, VNIIM and SMU had previously taken part in a key comparison with the Bureau International de Poids et Mesures (BIPM) and operated as link laboratories in order to evaluate the degree of equivalence of the participants' results with the key comparison reference value. These data form the basis of the results entered into the BIPM key comparison database for comparison COOMET.RI(I)-K1. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCRI Section I, according to the provisions of the CIPM Mutual Recognition Arrangement (MRA).

  17. KEY COMPARISON: Comparison of the standards for absorbed dose to water of the ENEA-INMRI (Italy) and the BIPM for 60Co γ rays

    NASA Astrophysics Data System (ADS)

    Kessler, C.; Allisy-Roberts, P. J.; Burns, D. T.; Guerra, A. S.; Laitano, R. F.; Pimpinella, M.

    2010-01-01

    A comparison of the standards for absorbed dose to water of the Istituto Nazionale di Metrologia delle Radiazioni Ionizzanti of the Ente per le Nuove Tecnologie, l'Energia e l'Ambiente, Italy (ENEA-INMRI), and of the Bureau International des Poids et Mesures (BIPM) has been made in 60Co gamma radiation under the auspices of the key comparison BIPM.RI(I)-K4. The comparison result, based on the calibration coefficients for three transfer standards and expressed as a ratio of the ENEA and the BIPM standards for absorbed dose to water, is 0.9999 (0.0044). The present 2007 result replaces the earlier ENEA value in this key comparison. The degrees of equivalence between the ENEA and the other participants in this comparison have been calculated and the results are given in the form of a matrix for the ten national metrology institutes (NMIs) that have published results in this ongoing comparison for absorbed dose to water. A graphical presentation is also given. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCRI Section I, according to the provisions of the CIPM Mutual Recognition Arrangement (MRA).

  18. Key comparison BIPM.RI(I)-K4 of the absorbed dose to water standards of the PTB, Germany and the BIPM in 60Co gamma radiation

    NASA Astrophysics Data System (ADS)

    Kessler, C.; Burns, D. T.; Kapsch, R.-P.; Krauss, A.

    2016-01-01

    An indirect comparison has been made of the standards for absorbed dose to water in 60Co radiation of the Physikalisch-Technische Bundesanstalt, (PTB), Germany and of the Bureau International des Poids et Mesures (BIPM). The measurements at the BIPM were carried out in October 2015. The comparison result, based on the calibration coefficients for two transfer standards and evaluated as a ratio of the PTB and the BIPM standards for absorbed dose to water, is 0.9977 with a combined standard uncertainty of 3.8 × 10-3. The results are analysed and presented in terms of degrees of equivalence for entry in the BIPM key comparison database. Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCRI, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

  19. 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.

  20. Time resolution of a 1-inch cylindrical CeBr{sub 3} crystal at {sup 60}Co energies

    SciTech Connect

    Vedia, V.; Fraile, L. M.; Olaizola, B.; Paziy, V.; Picado, E.; Udias, J. M.; Mach, H.

    2013-06-10

    We have measured time resolutions of a cylindrical CeBr{sub 3} scintillator of 1-inch in height and 1-inch in diameter coupled to two different fast photomultiplier tubes, Hamamatsu R9779 and Photonis XP20D0, as a function of applied high voltages and different settings of a Constant Fraction Discriminator ORTEC 935. The time resolution was measured using a time-delayed coincidence set-up involving a fast reference detector. The best result of 119(2) ps at {sup 60}Co energies was obtained for the CeBr{sub 3} crystal coupled to the Hamamatsu PMT. This result is comparable to the resolution of 107 ps reported for a LaBr{sub 3}(Ce) crystal of the same size. For the coupling of the CeBr{sub 3} scintillator to the Photonis PMT we got the time resolution of 146(2) ps.

  1. Determination of late-time Gamma-Ray (60Co) sensitivity of single diffusion Lot 2N2222A transistors.

    SciTech Connect

    DePriest, Kendall Russell; Kajder, Karen C.; Peters, Curtis D.

    2008-08-01

    Sandia National Laboratories (SNL) has embarked on a program to develop a methodology to use damage relations techniques (alternative experimental facilities, modeling, and simulation) to understand the time-dependent effects in transistors (and integrated circuits) caused by neutron irradiations in the Sandia Pulse Reactor-III (SPR-III) facility. The development of these damage equivalence techniques is necessary since SPR-III was shutdown in late 2006. As part of this effort, the late time {gamma}-ray sensitivity of a single diffusion lot of 2N2222A transistors has been characterized using one of the {sup 60}Co irradiation cells at the SNL Gamma Irradiation Facility (GIF). This report summarizes the results of the experiments performed at the GIF.

  2. Effect of 60Co-irradiation on the development and immunogenicity of Plasmodium berghei sporozoites in Anopheles stephensi mosquitoes

    SciTech Connect

    Smrkovski, L.L.; McConnell, E.; Tubergen, T.A.

    1983-10-01

    Protection conferred to mice by Plasmodium berghei sporozoites increased significantly when the time interval between 60Co-irradiation of the infected mosquitoes and harvest of sporozoites increased. One thousand sporozoites conferred no protection against challenge if harvested on the day of irradiation, but protected 60% of recipient mice when harvested 28 days postirradiation. When the time between feeding of mosquitoes and irradiation was varied, sporozoites from mosquitoes irradiated 3 days after feeding were infective for mice. Sporozoites from mosquitoes irradiated on day 10 postfeeding were not infective, but were immunogenic. In all experiments a decline occurred in the number of recoverable sporozoites over a 28-day period postirradiation to less than 10% of the yield on the day of irradiation.

  3. Microionization chamber air-kerma calibration coefficients as a function of photon energy for x-ray spectra in the range of 20-250 kVp relative to {sup 60}Co

    SciTech Connect

    Snow, J. R.; Micka, J. A.; DeWerd, L. A.

    2013-04-15

    Purpose: To investigate the applicability of a wide range of microionization chambers for reference dosimetry measurements in low- and medium-energy x-ray beams. Methods: Measurements were performed with six cylindrical microchamber models, as well as one scanning chamber and two Farmer-type chambers for comparison purposes. Air-kerma calibration coefficients were determined at the University of Wisconsin Accredited Dosimetry Calibration Laboratory for each chamber for a range of low- and medium-energy x-ray beams (20-250 kVp), with effective energies ranging from 11.5 keV to 145 keV, and a {sup 60}Co beam. A low-Z proof-of-concept microchamber was developed and calibrated with and without a high-Z silver epoxy on the collecting electrode. Results: All chambers composed of low-Z materials (Z{<=} 13), including the Farmer-type chambers, the scanning chamber, and the PTW TN31014 and the proof-of-concept microchambers, exhibited air-kerma calibration coefficients with little dependence on the quality of the beam. These chambers typically exhibited variations in calibration coefficients of less than 3% with the beam quality, for medium energy beams. However, variations in air-kerma calibration coefficients of greater than 50% were measured over the range of medium-energy x-ray beams for each of the microchambers containing high-Z collecting electrodes (Z > 13). For these high-Z chambers, which include the Exradin A14SL and A16 chambers, the PTW TN31006 chamber, the IBA CC01 chamber, and the proof-of-concept chamber containing silver, the average variation in air-kerma calibration coefficients between any two calibration beams was nearly 25% over the entire range of beam qualities investigated. Conclusions: Due to the strong energy dependence observed with microchambers containing high-Z components, these chambers may not be suitable dosimeters for kilovoltage x-ray applications, as they do not meet the TG-61 requirements. It is recommended that only microchambers

  4. Absorbed dose to water reference dosimetry using solid phantoms in the context of absorbed-dose protocols

    SciTech Connect

    Seuntjens, Jan; Olivares, Marina; Evans, Michael; Podgorsak, Ervin

    2005-09-15

    For reasons of phantom material reproducibility, the absorbed dose protocols of the American Association of Physicists in Medicine (AAPM) (TG-51) and the International Atomic Energy Agency (IAEA) (TRS-398) have made the use of liquid water as a phantom material for reference dosimetry mandatory. In this work we provide a formal framework for the measurement of absorbed dose to water using ionization chambers calibrated in terms of absorbed dose to water but irradiated in solid phantoms. Such a framework is useful when there is a desire to put dose measurements using solid phantoms on an absolute basis. Putting solid phantom measurements on an absolute basis has distinct advantages in verification measurements and quality assurance. We introduce a phantom dose conversion factor that converts a measurement made in a solid phantom and analyzed using an absorbed dose calibration protocol into absorbed dose to water under reference conditions. We provide techniques to measure and calculate the dose transfer from solid phantom to water. For an Exradin A12 ionization chamber, we measured and calculated the phantom dose conversion factor for six Solid Water{sup TM} phantoms and for a single Lucite phantom for photon energies between {sup 60}Co and 18 MV photons. For Solid Water{sup TM} of certified grade, the difference between measured and calculated factors varied between 0.0% and 0.7% with the average dose conversion factor being low by 0.4% compared with the calculation whereas for Lucite, the agreement was within 0.2% for the one phantom examined. The composition of commercial plastic phantoms and their homogeneity may not always be reproducible and consistent with assumed composition. By comparing measured and calculated phantom conversion factors, our work provides methods to verify the consistency of a given plastic for the purpose of clinical reference dosimetry.

  5. Uncertainty in 3D gel dosimetry

    NASA Astrophysics Data System (ADS)

    De Deene, Yves; Jirasek, Andrew

    2015-01-01

    Three-dimensional (3D) gel dosimetry has a unique role to play in safeguarding conformal radiotherapy treatments as the technique can cover the full treatment chain and provides the radiation oncologist with the integrated dose distribution in 3D. It can also be applied to benchmark new treatment strategies such as image guided and tracking radiotherapy techniques. A major obstacle that has hindered the wider dissemination of gel dosimetry in radiotherapy centres is a lack of confidence in the reliability of the measured dose distribution. Uncertainties in 3D dosimeters are attributed to both dosimeter properties and scanning performance. In polymer gel dosimetry with MRI readout, discrepancies in dose response of large polymer gel dosimeters versus small calibration phantoms have been reported which can lead to significant inaccuracies in the dose maps. The sources of error in polymer gel dosimetry with MRI readout are well understood and it has been demonstrated that with a carefully designed scanning protocol, the overall uncertainty in absolute dose that can currently be obtained falls within 5% on an individual voxel basis, for a minimum voxel size of 5 mm3. However, several research groups have chosen to use polymer gel dosimetry in a relative manner by normalizing the dose distribution towards an internal reference dose within the gel dosimeter phantom. 3D dosimetry with optical scanning has also been mostly applied in a relative way, although in principle absolute calibration is possible. As the optical absorption in 3D dosimeters is less dependent on temperature it can be expected that the achievable accuracy is higher with optical CT. The precision in optical scanning of 3D dosimeters depends to a large extend on the performance of the detector. 3D dosimetry with X-ray CT readout is a low contrast imaging modality for polymer gel dosimetry. Sources of error in x-ray CT polymer gel dosimetry (XCT) are currently under investigation and include inherent

  6. Air kerma based dosimetry calibration for the Leksell Gamma Knife

    SciTech Connect

    Meltsner, Sheridan Griffin; DeWerd, Larry A.

    2009-02-15

    No accepted official protocol exists for the dosimetry of the Leksell Gamma Knife registered (GK) stereotactic radiosurgery device. Establishment of a dosimetry protocol has been complicated by the unique partial-hemisphere arrangement of 201 individual {sup 60}Co beams simultaneously focused on the treatment volume and by the rigid geometry of the GK unit itself. This article proposes an air kerma based dosimetry protocol using either an in-air or in-acrylic phantom measurement to determine the absorbed dose rate of fields of the 18 mm helmet of a GK unit. A small-volume air ionization chamber was used to make measurements at the physical isocenter of three GK units. The absorbed dose rate to water was determined using a modified version of the AAPM Task Group 21 protocol designed for use with {sup 60}Co-based teletherapy machines. This experimentally determined absorbed dose rate was compared to the treatment planning system (TPS) absorbed dose rate. The TPS used with the GK unit is Leksell GammaPlan. The TPS absorbed dose rate at the time of treatment is the absorbed dose rate determined by the physicist at the time of machine commissioning decay corrected to the treatment date. The TPS absorbed dose rate is defined as absorbed dose rate to water at the isocenter of a water phantom with a radius of 8 cm. Measurements were performed on model B and C Gamma Knife units. The absorbed dose rate to water for the 18 mm helmet determined using air-kerma based calculations is consistently between 1.5% and 2.9% higher than the absorbed dose rate provided by the TPS. These air kerma based measurements allow GK dosimetry to be performed with an established dosimetry protocol and without complications arising from the use of and possible variations in solid phantom material. Measurements were also made with the same ionization chamber in a spherical acrylic phantom for comparison. This methodology will allow further development of calibration methods appropriate for the

  7. 3-D Imaging Based, Radiobiological Dosimetry

    PubMed Central

    Sgouros, George; Frey, Eric; Wahl, Richard; He, Bin; Prideaux, Andrew; Hobbs, Robert

    2008-01-01

    Targeted radionuclide therapy holds promise as a new treatment against cancer. Advances in imaging are making it possible to evaluate the spatial distribution of radioactivity in tumors and normal organs over time. Matched anatomical imaging such as combined SPECT/CT and PET/CT have also made it possible to obtain tissue density information in conjunction with the radioactivity distribution. Coupled with sophisticated iterative reconstruction algorithims, these advances have made it possible to perform highly patient-specific dosimetry that also incorporates radiobiological modeling. Such sophisticated dosimetry techniques are still in the research investigation phase. Given the attendant logistical and financial costs, a demonstrated improvement in patient care will be a prerequisite for the adoption of such highly-patient specific internal dosimetry methods. PMID:18662554

  8. INTRINSIC DOSIMETRY: A POTENTIAL NEW TOOL FOR NUCLEAR FORENSICS INVESTIGATIONS

    SciTech Connect

    Clark, Richard A.; Miller, Steven D.; Robertson, Dave J.; Gregg, Roger A.; Murphy, Mark K.; Schwantes, Jon M.

    2010-08-11

    Thermoluminescence (TL) dosimetry was used to measure dose effects on the raw stock material of borosilicate container glass from different geographical locations. Effects were studied at times up to 60 days post-irradiation at doses from 0.15 to 20 Gy. The minimum detectable dose using this technique was estimated to be 0.15 Gy which is roughly equivalent to a 24 hr irradiation 1 cm from a 50 ng source of 60Co. Two peaks were identified in the TL glow curve, a relatively unstable peak around 125°C and a more stable peak around 225°C. Differences in TL glow curve shape and intensity were also observed for the glasses from different geographical origins. We investigate radiation induced defects in glass to further develop the technique of intrinsic dosimetry–the measurement of the total absorbed dose received by the walls of a container holding radioactive material. Intrinsic dosimetry is intended to be used as an interrogation tool to provide enhanced pathway information on interdicted or newly discovered waste containers of unknown origin or history by considering the total absorbed dose received by a container in tandem with the physical characteristics of the radioactive material housed within that container. One hypothetical scenario is presented to illustrate the application of intrinsic dosimetry to waste management and nuclear forensics.

  9. Verification of total body photon irradiation dosimetry techniques

    SciTech Connect

    Kirby, T.H.; Hanson, W.F.; Cates, D.A.

    1988-05-01

    A method of verifying the dosimetry of patients undergoing total body irradiation (TBI) with photon beams having energies from cobalt-60 to 25 MV is presented. A simple set of spot checks at the TBI axis has been used to verify data used for TBI dosimetry. Calculations to verify dose delivered to TBI patients are done in the same manner as those irradiated at standard treatment distances. A simple method of effective field size determination for various anatomical locations in a typical adult is presented. Measurements in an Alderson phantom with thermoluminescent dosimeters and an ion chamber at several anatomical locations indicate that this calculational method can predict the dose along the patient axis to within 4% for /sup 60/Co and 18-MV photon beams, provided the dosimetry data are appropriate (as determined by the spot checks). Results of intercomparisons of TBI beam calibration, off-axis and depth-dose data at various institutions visited by the Radiological Physics Center are also presented.

  10. Effects of prenatal /sup 60/Co irradiation on postnatal neural, learning, and hormonal development of the squirrel monkey

    SciTech Connect

    Ordy, J.M.; Brizzee, K.R.; Dunlap, W.P.; Knight, C.

    1982-02-01

    The goals of this study were to examine the effects of 0, 50, and 100 rad of /sup 60/Co administered prenatally on postnatal development of neuromuscular coordination, visual discrimination learning, spontaneous light-dark stabilimeter activity, plasma cortisol, and somatometric growth rates of diurnal squirrel monkeys from birth to 90 days. In terms of accuracy, completeness, and time required for performance of reflexes and neuromuscular coordination, the performance of 50- and 100-rad offspring was less accurate and poorly coordinated and required more time for completion to that of controls. In visual orientation, discrimination, and reversal learning, the percentage correct responses of the 50- and 100-rad offspring were significantly lower than those of controls. Spontaneous light-dark stabilimeter activity of 50- and 100-rad offspring was significantly higher in the dark session than that of controls. Plasma cortisol was significantly higher in 100-rad infants than in controls. Comparisons of somatometric growth rates indicated that postnatal head circumference, crown-rump length, and to a lesser extent body weight increased at significantly slower rates in 50- and 100-rad offspring. These findings should provide essential information for formulating and carrying out multivariate behavioral, biochemical, and morphometric assessments of low-dose effects on the brain of primate offspring within demonstrable dose-response curves.

  11. Identification of Novel Chromosomal Aberrations Induced by 60Co-γ-Irradiation in Wheat-Dasypyrum villosum Lines

    PubMed Central

    Zhang, Jie; Jiang, Yun; Guo, Yuanlin; Li, Guangrong; Yang, Zujun; Xu, Delin; Xuan, Pu

    2015-01-01

    Mutations induced by radiation are widely used for developing new varieties of plants. To better understand the frequency and pattern of irradiation-induced chromosomal rearrangements, we irradiated the dry seeds of Chinese Spring (CS)-Dasypyrum villosum nullisomic-tetrasomic (6A/6D) addition (6V) line (2n = 44), WD14, with 60Co-γ-rays at dosages of 100, 200, and 300 Gy. The M0 and M1 generations were analyzed using Feulgen staining and non-denaturing fluorescence in situ hybridization (ND-FISH) by using oligonucleotide probes. Abnormal mitotic behavior and chromosomes with structural changes were observed in the M0 plants. In all, 39 M1 plants had structurally changed chromosomes, with the B genome showing the highest frequency of aberrations and tendency to recombine with chromosomes of the D genome. In addition, 19 M1 plants showed a variation in chromosome number. The frequency of chromosome loss was considerably higher for 6D than for the alien chromosome 6V, indicating that 6D is less stable after irradiation. Our findings suggested that the newly obtained γ-induced genetic materials might be beneficial for future wheat breeding programs and functional gene analyses. PMID:26694350

  12. Effect of low /sup 60/Co dose rates on sister chromatid exchange incidence in the benthic worm. Neanthes arenaceodentata

    SciTech Connect

    Harrison, F.L.; Rice, D.W. Jr.

    1981-10-13

    The usefulness of sister chromatid exchange (SCE) induction as a measure of low-level radiation effect was examined in a benthic marine worm, Neanthes arenaceodentata. Larvae were exposed to /sup 60/Co radiation for 12 to 24 h at total doses ranging from 0.5 to 309 R and at dose rates from 0.04 to 13 R/h. Animals exposed at intermediate dose rates (0.5, 0.6, 1.25, 2.0, and 2.5 R/h) had SCE frequencies per chromosome about twice that of those receiving no radiation (controls), whereas those exposed at the higher dose rates (7.0 and 13 R/h) had SCE frequencies lower than the controls. Animals exposed at the lower dose rates (0.04 and 0.1 R/h) had lower SCE frequencies than those exposed at intermediate dose rates (and higher SCE frequencies than controls). The length of chromosome pair number one differed among metaphase spreads and was used as an index of chromosome condensation in a given metaphase. Because there is a possibility that chromosome morphology may affect the ability to resolve SCEs, morphology will be monitored in future studies. A preliminary experiment was performed to assess the effects of 2.2 and 11.5 R/h for 24 h on growth and development. Larvae observed at 6 and 17 d after irradiation did not have significantly different numbers of abnormal larvae or survival rates.

  13. Identification of Novel Chromosomal Aberrations Induced by (60)Co-γ-Irradiation in Wheat-Dasypyrum villosum Lines.

    PubMed

    Zhang, Jie; Jiang, Yun; Guo, Yuanlin; Li, Guangrong; Yang, Zujun; Xu, Delin; Xuan, Pu

    2015-01-01

    Mutations induced by radiation are widely used for developing new varieties of plants. To better understand the frequency and pattern of irradiation-induced chromosomal rearrangements, we irradiated the dry seeds of Chinese Spring (CS)-Dasypyrum villosum nullisomic-tetrasomic (6A/6D) addition (6V) line (2n = 44), WD14, with (60)Co-γ-rays at dosages of 100, 200, and 300 Gy. The M₀ and M₁ generations were analyzed using Feulgen staining and non-denaturing fluorescence in situ hybridization (ND-FISH) by using oligonucleotide probes. Abnormal mitotic behavior and chromosomes with structural changes were observed in the M₀ plants. In all, 39 M₁ plants had structurally changed chromosomes, with the B genome showing the highest frequency of aberrations and tendency to recombine with chromosomes of the D genome. In addition, 19 M₁ plants showed a variation in chromosome number. The frequency of chromosome loss was considerably higher for 6D than for the alien chromosome 6V, indicating that 6D is less stable after irradiation. Our findings suggested that the newly obtained γ-induced genetic materials might be beneficial for future wheat breeding programs and functional gene analyses. PMID:26694350

  14. Paramecium tetraurelia growth stimulation under low-level chronic irradiation: investigations on a possible mechanism. [/sup 60/Co

    SciTech Connect

    Croute, F.; Soleilhavoup, J.P.; Vidal, S.; Dupouy, D.; Planel, H.

    1982-12-01

    Experiments were carried out to demonstrate the effects of low-level chronic irradiation on Paramecium tetraurelia proliferation. Biological effects were strongly dependent on the bacterial density of culture medium and more exactly on the catalase content of the medium. Significant growth stimulation was found under /sup 60/Co chronic irradiation at a dose rate of 2 rad/year when paramecia were grown in a medium containing a high bacterial concentration (2.5 x 10/sup 2/ cells/m) or supplemented with catalase (300 U/ml). In a medium with a low bacterial density (1 x 10/sup 6/ cell/ml) or supplemented with a catalase activity inhibitor, growth simulation was preceded by a transitory inhibiting effect which could be correlated with extracellularly radioproduced H/sub 2/O/sub 2/. H/sub 2/O/sub 2/ addition appeared to be able to simulate the biological effects of chronic irradiation. A possible mechanism is discussed.We proposed that the stimulating effects were the result of intracellular enzymatic scavenging of radioproduced H/sub 2/O/sub 2/.

  15. Monte Carlo modeling of 60Co HDR brachytherapy source in water and in different solid water phantom materials

    PubMed Central

    Sahoo, S.; Selvam, T. Palani; Vishwakarma, R. S.; Chourasiya, G.

    2010-01-01

    The reference medium for brachytherapy dose measurements is water. Accuracy of dose measurements of brachytherapy sources is critically dependent on precise measurement of the source–detector distance. A solid phantom can be precisely machined and hence source–detector distances can be accurately determined. In the present study, four different solid phantom materials such as polymethylmethacrylate (PMMA), polystyrene, Solid Water, and RW1 are modeled using the Monte Carlo methods to investigate the influence of phantom material on dose rate distributions of the new model of BEBIG 60Co brachytherapy source. The calculated dose rate constant is 1.086 ± 0.06% cGy h−1 U−1 for water, PMMA, polystyrene, Solid Water, and RW1. The investigation suggests that the phantom materials RW1 and Solid Water represent water-equivalent up to 20 cm from the source. PMMA and polystyrene are water-equivalent up to 10 cm and 15 cm from the source, respectively, as the differences in the dose data obtained in these phantom materials are not significantly different from the corresponding data obtained in liquid water phantom. At a radial distance of 20 cm from the source, polystyrene overestimates the dose by 3% and PMMA underestimates it by about 8% when compared to the corresponding data obtained in water phantom. PMID:20177566

  16. Radiation damage of contact structures with diffusion barriers exposed to irradiation with {sup 60}Co{gamma}-ray photons

    SciTech Connect

    Belyaev, A. E.; Boltovets, N. S.; Konakova, R. V. Milenin, V. V.; Sveshnikov, Yu. N.; Sheremet, V. N.

    2010-04-15

    The effect of ionizing radiation of {sup 60}Co {gamma}-ray photons in the dose range 10{sup 4}-2 x 10{sup 9} rad on metal-semiconductor Au-ZrB{sub x}-AlGaN/GaN and Au-TiB{sub x}-Al-Ti-n-GaN contacts and Au-ZrB{sub x}-n-GaN Schottky diodes is examined. The contacts with the TiB{sub x} and ZrB{sub x} diffusion barriers do not degrade under the effect of ionizing radiation if the dose does not exceed 10{sup 8} rad. The Au-ZrB{sub x}-n-GaN Schottky diodes remain stable in the dose range 10{sup 4}-10{sup 6} rad. As the radiation dose is increased to {>=}10{sup 8} rad, the damage to the contact metallization increases and is accompanied by formation of through pores, which is conducive to accumulation of oxygen at the Au-ZrB{sub x}(TiB{sub x}) interfaces and to an increase in mass transport of atoms in contact-forming layers. In this case, irradiation-caused degradation of the Schottky diodes is observed. Possible mechanisms of radiation damage of contact structures with diffusion barriers are analyzed.

  17. 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

  18. Performance analysis and determination of the p(wall) correction factor for 60Co gamma-ray beams for Wellhöfer Roos-type plane-parallel chambers.

    PubMed

    Palm, Asa; Czap, Ladislav; Andreo, Pedro; Mattsson, Olof

    2002-02-21

    The wall perturbation correction factor p(wall) in 60Co for Wellhöfer Roos-type plane-parallel ionization chambers is determined experimentally and compared with the results of a previous study using PTW-Roos chambers (Palm et al 2000 Phys. Med. Biol. 45 971-81). Five ionization chambers of the type Wellhöfer PPC-35 (or its equivalent PPC-40) are used for the analysis. Wall perturbation correction factors are obtained by assuming N(D,air) chamber factors determined by cross-calibration in a high-energy electron and in a 60Co gamma-ray beam to be equal, and by assigning any differences to the wall perturbation factor. The procedure yields a p(wall) value of 1.018 (u(c) = 0.010), which is slightly higher than the value 1.014 (u(c) = 0.010) formerly obtained for the PTW-Roos chambers using the N(D,air) method. The chamber-to-chamber variation in p(wall) for the Wellhöfer-Roos chambers is found to be very small, with a maximum difference of 0.3%. The effect of using new p(cav) values for graphite-walled Farmer-type chambers used in water in electron beams is to decrease p(wall) by approximately 0.5%. The long- and short-term stability of the Roos-type chambers manufactured by Wellhöfer is investigated by measurements at the IAEA Dosimetry Laboratory in Vienna, Austria, and at the Sahlgrenska University Hospital in Göteborg, Sweden. Calibrations made at the IAEA over several months show variations in the N(D,w) calibration factors larger than expected. based on previous experiences with PTW-Roos chambers. Measurements of the short-term stability of the Wellhöfer-Roos chambers show a marked increase in chamber response for the time the chambers are immersed in water, pointing to a possible problem in the chamber design. As a consequence of these findings, Wellhöfer is currently working on a re-design of the chamber to solve the stability problem. PMID:11900195

  19. SEU measurements using /sup 252/CF fission particles, on CMOS static RAMS, subjected to a continuous period of low dose rate /sup 60/CO irradiation

    SciTech Connect

    Sanderson, T.K.; Mapper, D.; Stephen, J.H.; Farren, J.; Adams, L.; Harboe-Sorensen, R.

    1987-12-01

    SEU measurements have been made on a number of CMOS static RAMs over a period of eight months while they were being continuously irradiated with /sup 60/Co gamma rays. The results are discussed and compared with those of other workers using different methods.

  20. 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.

  1. A comparison of large-scale electron beam and bench-scale 60Co irradiations of simulated aqueous waste streams

    NASA Astrophysics Data System (ADS)

    Kurucz, Charles N.; Waite, Thomas D.; Otaño, Suzana E.; Cooper, William J.; Nickelsen, Michael G.

    2002-11-01

    The effectiveness of using high energy electron beam irradiation for the removal of toxic organic chemicals from water and wastewater has been demonstrated by commercial-scale experiments conducted at the Electron Beam Research Facility (EBRF) located in Miami, Florida and elsewhere. The EBRF treats various waste and water streams up to 450 l min -1 (120 gal min -1) with doses up to 8 kilogray (kGy). Many experiments have been conducted by injecting toxic organic compounds into various plant feed streams and measuring the concentrations of compound(s) before and after exposure to the electron beam at various doses. Extensive experimentation has also been performed by dissolving selected chemicals in 22,700 l (6000 gal) tank trucks of potable water to simulate contaminated groundwater, and pumping the resulting solutions through the electron beam. These large-scale experiments, although necessary to demonstrate the commercial viability of the process, require a great deal of time and effort. This paper compares the results of large-scale electron beam irradiations to those obtained from bench-scale irradiations using gamma rays generated by a 60Co source. Dose constants from exponential contaminant removal models are found to depend on the source of radiation and initial contaminant concentration. Possible reasons for observed differences such as a dose rate effect are discussed. Models for estimating electron beam dose constants from bench-scale gamma experiments are presented. Data used to compare the removal of organic compounds using gamma irradiation and electron beam irradiation are taken from the literature and a series of experiments designed to examine the effects of pH, the presence of turbidity, and initial concentration on the removal of various organic compounds (benzene, toluene, phenol, PCE, TCE and chloroform) from simulated groundwater.

  2. Clinical data from one year follow-up of victims of the radiation accident with 60Co in Bulgaria.

    PubMed

    Djounova, J; Guleva, I; Negoicheva, K; Mileva, I; Panova, D; Rupova, I

    2014-09-01

    A severe radiation accident occurred on 14 June 2011 in an industrial irradiation facility for medical equipment sterilization in Bulgaria. Five people were exposed for 5-10 min to a 60Co source containing 137 TBq. The Emergency Department of the National Centre of Radiobiology and Radiation Protection (NCRRP), Bulgaria, put into practice the plans for providing medical care in radiation accidents and the procedures developed for assessment of injury severity, the decision-making algorithm regarding subsequent treatment, and the therapy for persons affected. The activities performed for initial assessment of the severity of injury of irradiated patients were published in 2012. Based on predictive assessments of the severity of radiation damage, it was decided that the victims required hospitalization at a specialized hematology clinic. Percy Hospital in Paris was chosen for this purpose. The aim of this report is to present the results of 1-y follow-up for three of the victims. Sadly, 1 mo after the accident, Patient 4 died from a heart attack. The medical opinion was that this was not a direct outcome of the irradiation. Patient 5 was only followed up for 4 mo (118 d) because medical follow-up is voluntary, and despite repeated calls, the patient did not respond. Medical examinations by a physician as well as hematology and biochemical tests were performed using standard laboratory methods. The obtained results were compared to the victims' personal reference limits obtained from annual health monitoring. After the accident, the recovery to normal content of peripheral blood cells was observed in all victims. Nevertheless, there were observed cases of thrombocytopenia, granulocytopenia, and leucocytopenia at various times after exposure. During the period of observation, morphological changes in red blood cells such as anisomicrocitosis, macrocytes, megalocytes, and polychromatic erythrocytes were demonstrated. During the 1-y observation period, all victims showed

  3. 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.

  4. 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).

  5. Fast neutron dosimetry. Progress report, July 1, 1979-June 30, 1980

    SciTech Connect

    Attix, F.H.

    1980-01-01

    Progress is reported in: the development and testing of new gas mixtures more suitable for fast neutron dosimetry using the common A150-type Tissue-equivalent plastic ion chambers; comparison of photon doses determined with a graphite-walled proportional counter and with paired dosimeters irradiated by 14.8-MeV neutrons; a detector for the direct measurement of LET distributions from irradiation with fast neutrons; LET distributions from fast neutron irradiation of TE-plastic and graphite measured in a cylindrically symmetric geometry; progress in development of a tandem fast neutron and /sup 60/Co gamma ray source irradiation facility; an approach to the correlation of cellular response with lineal energy; calculated and measured HTO atmospheric dispersion rates within meters of a release site; application of cavity theory to fast neutrons; and fast neutron dosimetry by thermally stimulated currents in Al/sub 2/O/sub 3/. (GHT)

  6. Reactor Dosimetry State of the Art 2008

    NASA Astrophysics Data System (ADS)

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

    2009-08-01

    Oral session 1: Retrospective dosimetry. Retrospective dosimetry of VVER 440 reactor pressure vessel at the 3rd unit of Dukovany NPP / M. Marek ... [et al.]. Retrospective dosimetry study at the RPV of NPP Greifswald unit 1 / J. Konheiser ... [et al.]. Test of prototype detector for retrospective neutron dosimetry of reactor internals and vessel / K. Hayashi ... [et al.]. Neutron doses to the concrete vessel and tendons of a magnox reactor using retrospective dosimetry / D. A. Allen ... [et al.]. A retrospective dosimetry feasibility study for Atucha I / J. Wagemans ... [et al.]. Retrospective reactor dosimetry with zirconium alloy samples in a PWR / L. R. Greenwood and J. P. Foster -- Oral session 2: Experimental techniques. Characterizing the Time-dependent components of reactor n/y environments / P. J. Griffin, S. M. Luker and A. J. Suo-Anttila. Measurements of the recoil-ion response of silicon carbide detectors to fast neutrons / F. H. Ruddy, J. G. Seidel and F. Franceschini. Measurement of the neutron spectrum of the HB-4 cold source at the high flux isotope reactor at Oak Ridge National Laboratory / J. L. Robertson and E. B. Iverson. Feasibility of cavity ring-down laser spectroscopy for dose rate monitoring on nuclear reactor / H. Tomita ... [et al.]. Measuring transistor damage factors in a non-stable defect environment / D. B. King ... [et al.]. Neutron-detection based monitoring of void effects in boiling water reactors / J. Loberg ... [et al.] -- Poster session 1: Power reactor surveillance, retrospective dosimetry, benchmarks and inter-comparisons, adjustment methods, experimental techniques, transport calculations. Improved diagnostics for analysis of a reactor pulse radiation environment / S. M. Luker ... [et al.]. Simulation of the response of silicon carbide fast neutron detectors / F. Franceschini, F. H. Ruddy and B. Petrović. NSV A-3: a computer code for least-squares adjustment of neutron spectra and measured dosimeter responses / J. G

  7. A comparison of conventional /sup 60/Co testing and low dose-accumulation-rate exposure of metal-gate CMOS IC'S

    SciTech Connect

    Roeske, S.B.; Edwards, W.H.; Gammill, P.E.; Puariea, J.W.; Zipay, J.W.

    1984-12-01

    Data are presented for the CD4000 family of Hi-Rel, rad-hard, metal-gate CMOS ICs which show a much greater tolerance to low dose-rate ionizing radiation than that observed with ''conventional rate'' (approximately 10/sup 6/ rad(Si)/hr) /sup 60/Co testing. Data obtained using conventional rate /sup 60/Co irradiations followed by either a 24-hour, high-temperature (100/sup 0/C) anneal or a 65-day, room temperature anneal are in good agreement with data obtained by exposing similar parts at a low dose-accumulation rate (daily 17second, 5000 rad(Si) exposures) for 200 consecutive days. Graphs of thresholds, output drive, and propagation delay for both low doseaccumulation rate and conventional rate exposures are included.

  8. Monte Carlo calculations of free ammonia production in deoxygenated solutions of glycylglycine irradiated by X rays and 60Co gamma rays

    SciTech Connect

    Bolch, W.E.; Turner, J.E.; Yoshida, H.; Jacobson, K.B.; Wright, H.A.; Hamm, R.N. )

    1990-03-01

    Detailed-history Monte Carlo computer codes were used to simulate the formation, diffusion, and chemical reaction of free-radical species within deoxygenated aqueous solutions of glycylglycine irradiated by 250-kVp X rays and by 60Co gamma rays. In one reaction, hydrated electrons react with the glycylglycine solute to produce unbound, or free, ammonia. This reaction is complete by 10(-6) s within individual electron tracks for glycylglycine concentrations greater than or equal to 0.025 M. For solute concentrations from 0.025 to 1.2 M, calculated G values of free ammonia are in excellent agreement with measured values. In addition, the computer model predicts a statistically significant difference between the G value of free ammonia produced under X irradiation and that produced under 60Co gamma irradiation.

  9. Comparison of Life-Stage-Dependent Internal Dosimetry for Bisphenol A, Ethinyl Estradiol, a Reference Estrogen, and Endogenous Estradiol to Test an Estrogenic Mode of Action in Sprague Dawley Rats

    PubMed Central

    Churchwell, Mona I.; Camacho, Luísa; Vanlandingham, Michelle M.; Twaddle, Nathan C.; Sepehr, Estatira; Delclos, K. Barry; Fisher, Jeffrey W.; Doerge, Daniel R.

    2014-01-01

    Bisphenol A (BPA) was administered by gavage (2.5–300,000 μg/kg body weight (bw)/day) to pregnant Sprague Dawley dams, newborn pups, and continuing into adulthood. Aglycone (i.e., unconjugated and active) and conjugated (i.e., inactive) BPA were evaluated by liquid chromatography electrospray tandem mass spectrometry (LC-ES/MS/MS) in serum to better interpret toxicological endpoints measured in the study. Ethinyl estradiol (EE2, 0.5 and 5 μg/kg bw/day) and the endogenous hormones, 17β-estradiol (E2) and testosterone, were similarly evaluated. Mean BPA aglycone levels in vehicle and naïve control rat serum (0.02–0.5 ng/ml) indicated sample processing artifact, consistent with literature reports of a propensity for postexposure blood contamination by BPA. Direct measurements of BPA-glucuronide in vehicle and naïve control serum (2–10nM) indicated unintentional exposure and metabolism at levels similar to those produced by 2.5 μg/kg bw/day BPA (7–10nM), despite careful attention to potential BPA inputs (diet, drinking water, vehicle, cages, bedding, and dust) and rigorous dosing solution certification and delivery. The source of this exposure could not be identified, but interpretation of the toxicological effects, observed only at the highest BPA doses, was not compromised. Internal exposures to BPA and EE2 aglycones were highest in young rats. When maximal serum concentrations from the two highest BPA doses and both EE2 doses were compared with concurrent levels of endogenous E2, the ERα binding equivalents were similar to or above those of endogenous E2 in male and female rats of all ages tested. Such evaluations of estrogenic internal dosimetry and comprehensive evaluation of contamination impact should aid in extrapolating risks from human BPA exposures. PMID:24496641

  10. Energy Metabolism and Human Dosimetry of Tritium

    SciTech Connect

    Galeriu, D.; Takeda, H.; Melintescu, A.; Trivedi, A

    2005-07-15

    In the frame of current revision of human dosimetry of {sup 14}C and tritium, undertaken by the International Commission of Radiological Protection, we propose a novel approach based on energy metabolism and a simple biokinetic model for the dynamics of dietary intake (organic {sup 14}C, tritiated water and Organically Bound Tritium-OBT). The model predicts increased doses for HTO and OBT comparing to ICRP recommendations, supporting recent findings.

  11. Quantities and units in radiation protection dosimetry

    NASA Astrophysics Data System (ADS)

    Jennings, W. A.

    1994-08-01

    A new report, entitled Quantities and Units in Radiation Protection Dosimetry, has recently been published by the international Commission on Radiation Units and Measurements. That report (No. 51) aims to provide a coherent system of quantities and units for purposes of measurement and calculation in the assessment of compliance with dose limitations. The present paper provides an extended summary of that report, including references to the operational quantities needed for area and individual monitoring of external radiations.

  12. 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.

  13. Numerical simulation of 60Co-gamma irradiation effects on electrical characteristics of n-type FZ silicon X-ray detectors

    NASA Astrophysics Data System (ADS)

    Vigneshwara Raja, P.; Rao, C. V. S.; Narasimha Murty, N. V. L.

    2016-07-01

    This paper describes the gamma irradiation effects on the electrical characteristics of n-type float zone (FZ) silicon detectors by incorporating a 4-level 60Co-gamma radiation damage model in the commercial device simulator for plasma X-ray tomography diagnostics. In the simulations, a segmented n-type silicon detector (i.e. p+-n-n+ structure) is considered with varying substrate resistivity (ρ = 5.4, 2.5, and 0.3 kΩ cm). The simulation results have been validated with the reported experimental measurements carried out on similar device structures. The 60Co-gamma irradiation induced changes in the electrical characteristics of the detectors are analyzed up to the dose of 3500 Mrad. The possible gamma induced degradation in the X-ray response of the detectors is investigated from the changes in the effective doping concentration and the leakage current of the detectors. The survival of the gamma irradiated detectors is predicted from the simulation studies. The comparison between the 60Co-gamma and 14.1 MeV neutron irradiation effects (typical fusion environments) on silicon detectors is attempted.

  14. Standardization of the radionuclides (60)Co and (59)Fe by digital 4πβ(PC)-γ(NaI) coincidence counting.

    PubMed

    Zhang, Ming; Yao, Shunhe; Liang, Junchen; Liu, Haoran

    2016-03-01

    The digital coincidence counting (DCC) technique has been developed at NIM, China to replace the classical analog coincidence units in the 4πβ-γ counting system. The detector system comprises two NaI (Tl) γ-ray detectors and a 4πβ proportional counter (PC) operated with a mixture of argon and methane at atmospheric pressure in a gas flow arrangement. To update the activity results of radionuclide (60)Co in the KCDB and contribute to the APMP.RI(II)-K2.Fe-59 comparison, (60)Co and (59)Fe dry sources were prepared and measured using the digital 4πβ(PC)-γ(NaI) coincidence system by applying the efficiency extrapolation method. For (60)Co nuclide, the activity concentration value equal to 290.6kBqg(-1) with a relative standard uncertainty of 0.26%, is consistent with the result given by the calibrated ionization chamber. For the nuclide (59)Fe, the activity concentration value at the reference date was 471.7kBqg(-1) with a relative standard uncertainty of 0.34%. This value is in good agreement with the result obtained with the HPGe γ spectrometry, which was calibrated by using a series of standard point sources from PTB. PMID:26651175

  15. Pre-assessment of dose rates of (134)Cs, (137)Cs, and (60)Co for marine biota from discharge of Haiyang Nuclear Power Plant, China.

    PubMed

    Li, Jingjing; Liu, Senlin; Zhang, Yongxing; Chen, Ling; Yan, Yuan; Cheng, Weiya; Lou, Hailin; Zhang, Yongbao

    2015-09-01

    Haiyang Nuclear Power Plant to be built in China was selected as a case for the dose pre-assessment for marine biota in this study. The concentrations of Cs and Co in organisms (turbot, yellow croaker, swimming crab, abalone, sea cucumber, and sea lettuce), seawater, and bottom sediment sampled on-site were measured by neutron activation analysis, and the site-specific transfer parameters (concentration ratios and distribution coefficients) of Cs and Co were calculated. (134)Cs, (137)Cs, and (60)Co activity concentrations in the organisms and the sediment at the site were calculated with the site-specific transfer parameters and the anticipated activity concentrations in the liquid effluent of the nuclear power plant. The ERICA tool was used to estimate the dose rates of (134)Cs, (137)Cs, and (60)Co to the selected organisms based on the biological models developed. The total dose rates of (134)Cs, (137)Cs, and (60)Co to the six organisms were all <0.001 μGy h(-1). PMID:26005771

  16. A novel challenge test incorporating irradiation (60Co) of compost sub-samples to validate thermal lethality towards pathogenic bacteria.

    PubMed

    Moore, John E; Watabe, Miyuki; Stewart, Andrew; Cherie Millar, B; Rao, Juluri R

    2009-01-01

    Maturing compost heaps normally attaining temperatures ranging from 55 to 65 degrees C is generally regarded to conform to recommended biological risks and sanitation standards for composts stipulated by either EU or US-EPA. Composted products derived from animal sources are further required by EU biohazard safety regulatory legislation that such composts either attain 70 degrees C for over 3h during maturation or via treatment at 70 degrees C for 1h before being considered for dispensation on land. The setting of the upper limit of thermal lethality at 70 degrees C/1h for achieving biosecurity of the animal waste composted products (e.g. pelleted fertilizer formulations) is not properly substantiated by specific validation tests, comprising a 'wipe-out' step (usually via autoclaving) followed by inoculation of a prescribed bacterium, exposure to 70 degrees C/1h and the lethality determined. Pelleted formulations of composts are not amenable for wet methods (autoclaving) for wipe-out sterilization step as this is detrimental to the pellet and compromises sample integrity. This study describes a laboratory method involving the employment of ((60)Co) irradiation 'wipe-out' step to: (a) compost sub-samples drawn from compost formulation heaps and (b) pelleted products derived from composted animal products while determining the thermal lethality of a given time/temperature (70 degrees C/1h) treatment process and by challenging the irradiated sample (not just with one bacterium but), out with 10 potential food-poisoning organisms from the bacterial genera (Campylobacter, Escherichia, Listeria, Salmonella, Yersinia) frequently detected in pig and poultry farm wastes. This challenge test on compost sub-samples can be a useful intervention ploy for 'inspection and validation' technique for composters during the compost maturity process, whose attainment of temperatures of 55-65 degrees C is presumed sufficient for attainment of sanitation. Stringent measures are further

  17. Proceedings of the third conference on radiation protection and dosimetry

    SciTech Connect

    Swaja, R.E.; Sims, C.S.; Casson, W.H.

    1991-10-01

    The Third Conference on Radiation Protection and Dosimetry was held during October 21--24, 1991, at the Sheraton Plaza Hotel in Orlando, Florida. This meeting was designed with the objectives of promoting communication among applied, research, regulatory, and standards personnel involved in radiation protection, and providing them with sufficient information to evaluate their programs. To meet these objectives, a technical program consisting of more than 75 invited and contributed oral presentations encompassing all aspects of radiation protection was prepared. General topics considered in the technical session included external dosimetry, internal dosimetry, instruments, accident dosimetry, regulations and standards, research advances, and applied program experience. In addition, special sessions were held to afford attendees the opportunity to make short presentations of recent work or to discuss topics of general interest. Individual reports are processed separately on the database.

  18. Evaluation of dual energy quantitative CT for determining the spatial distributions of red marrow and bone for dosimetry in internal emitter radiation therapy

    SciTech Connect

    Goodsitt, Mitchell M. Shenoy, Apeksha; Howard, David; Christodoulou, Emmanuel; Dewaraja, Yuni K.; Shen, Jincheng; Schipper, Matthew J.; Wilderman, Scott; Chun, Se Young

    2014-05-15

    Purpose: To evaluate a three-equation three-unknown dual-energy quantitative CT (DEQCT) technique for determining region specific variations in bone spongiosa composition for improved red marrow dose estimation in radionuclide therapy. Methods: The DEQCT method was applied to 80/140 kVp images of patient-simulating lumbar sectional body phantoms of three sizes (small, medium, and large). External calibration rods of bone, red marrow, and fat-simulating materials were placed beneath the body phantoms. Similar internal calibration inserts were placed at vertebral locations within the body phantoms. Six test inserts of known volume fractions of bone, fat, and red marrow were also scanned. External-to-internal calibration correction factors were derived. The effects of body phantom size, radiation dose, spongiosa region segmentation granularity [single (∼17 × 17 mm) region of interest (ROI), 2 × 2, and 3 × 3 segmentation of that single ROI], and calibration method on the accuracy of the calculated volume fractions of red marrow (cellularity) and trabecular bone were evaluated. Results: For standard low dose DEQCT x-ray technique factors and the internal calibration method, the RMS errors of the estimated volume fractions of red marrow of the test inserts were 1.2–1.3 times greater in the medium body than in the small body phantom and 1.3–1.5 times greater in the large body than in the small body phantom. RMS errors of the calculated volume fractions of red marrow within 2 × 2 segmented subregions of the ROIs were 1.6–1.9 times greater than for no segmentation, and RMS errors for 3 × 3 segmented subregions were 2.3–2.7 times greater than those for no segmentation. Increasing the dose by a factor of 2 reduced the RMS errors of all constituent volume fractions by an average factor of 1.40 ± 0.29 for all segmentation schemes and body phantom sizes; increasing the dose by a factor of 4 reduced those RMS errors by an average factor of 1.71 ± 0.25. Results

  19. Evaluation of dual energy quantitative CT for determining the spatial distributions of red marrow and bone for dosimetry in internal emitter radiation therapy

    PubMed Central

    Goodsitt, Mitchell M.; Shenoy, Apeksha; Shen, Jincheng; Howard, David; Schipper, Matthew J.; Wilderman, Scott; Christodoulou, Emmanuel; Chun, Se Young; Dewaraja, Yuni K.

    2014-01-01

    Purpose: To evaluate a three-equation three-unknown dual-energy quantitative CT (DEQCT) technique for determining region specific variations in bone spongiosa composition for improved red marrow dose estimation in radionuclide therapy. Methods: The DEQCT method was applied to 80/140 kVp images of patient-simulating lumbar sectional body phantoms of three sizes (small, medium, and large). External calibration rods of bone, red marrow, and fat-simulating materials were placed beneath the body phantoms. Similar internal calibration inserts were placed at vertebral locations within the body phantoms. Six test inserts of known volume fractions of bone, fat, and red marrow were also scanned. External-to-internal calibration correction factors were derived. The effects of body phantom size, radiation dose, spongiosa region segmentation granularity [single (∼17 × 17 mm) region of interest (ROI), 2 × 2, and 3 × 3 segmentation of that single ROI], and calibration method on the accuracy of the calculated volume fractions of red marrow (cellularity) and trabecular bone were evaluated. Results: For standard low dose DEQCT x-ray technique factors and the internal calibration method, the RMS errors of the estimated volume fractions of red marrow of the test inserts were 1.2–1.3 times greater in the medium body than in the small body phantom and 1.3–1.5 times greater in the large body than in the small body phantom. RMS errors of the calculated volume fractions of red marrow within 2 × 2 segmented subregions of the ROIs were 1.6–1.9 times greater than for no segmentation, and RMS errors for 3 × 3 segmented subregions were 2.3–2.7 times greater than those for no segmentation. Increasing the dose by a factor of 2 reduced the RMS errors of all constituent volume fractions by an average factor of 1.40 ± 0.29 for all segmentation schemes and body phantom sizes; increasing the dose by a factor of 4 reduced those RMS errors by an average factor of 1.71 ± 0.25. Results

  20. Energy response improvement for photon dosimetry using pulse analysis

    NASA Astrophysics Data System (ADS)

    Zaki, Dizaji H.

    2016-02-01

    During the last few years, active personal dosimeters have been developed and have replaced passive personal dosimeters in some external monitoring systems, frequently using silicon diode detectors. Incident photons interact with the constituents of the diode detector and produce electrons. These photon-induced electrons deposit energy in the detector's sensitive region and contribute to the response of diode detectors. To achieve an appropriate photon dosimetry response, the detectors are usually covered by a metallic layer with an optimum thickness. The metallic cover acts as an energy compensating shield. In this paper, a software process is performed for energy compensation. Selective data sampling based on pulse height is used to determine the photon dose equivalent. This method is applied to improve the energy response in photon dosimetry. The detector design is optimized for the response function and determination of the photon dose equivalent. Photon personal dose equivalent is determined in the energy range of 0.3-6 MeV. The error values of the calculated data for this wide energy range and measured data for 133Ba, 137Cs, 60Co and 241Am-Be sources respectively are up to 20% and 15%. Fairly good agreement is seen between simulation and dose values obtained from our process and specifications from several photon sources.

  1. 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'.

  2. 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.

  3. Application of the ICRP/ICRU reference computational phantoms to internal dosimetry: calculation of specific absorbed fractions of energy for photons and electrons.

    PubMed

    Hadid, L; Desbrée, A; Schlattl, H; Franck, D; Blanchardon, E; Zankl, M

    2010-07-01

    The emission of radiation from a contaminated body region is connected with the dose received by radiosensitive tissue through the specific absorbed fractions (SAFs) of emitted energy, which is therefore an essential quantity for internal dose assessment. A set of SAFs were calculated using the new adult reference computational phantoms, released by the International Commission on Radiological Protection (ICRP) together with the International Commission on Radiation Units and Measurements (ICRU). Part of these results has been recently published in ICRP Publication 110 (2009 Adult reference computational phantoms (Oxford: Elsevier)). In this paper, we mainly discuss the results and also present them in numeric form. The emission of monoenergetic photons and electrons with energies ranging from 10 keV to 10 MeV was simulated for three source organs: lungs, thyroid and liver. SAFs were calculated for four target regions in the body: lungs, colon wall, breasts and stomach wall. For quality assurance purposes, the simulations were performed simultaneously at the Helmholtz Zentrum München (HMGU, Germany) and at the Institute for Radiological Protection and Nuclear Safety (IRSN, France), using the Monte Carlo transport codes EGSnrc and MCNPX, respectively. The comparison of results shows overall agreement for photons and high-energy electrons with differences lower than 8%. Nevertheless, significant differences were found for electrons at lower energy for distant source/target organ pairs. Finally, the results for photons were compared to the SAF values derived using mathematical phantoms. Significant variations that can amount to 200% were found. The main reason for these differences is the change of geometry in the more realistic voxel body models. For electrons, no SAFs have been computed with the mathematical phantoms; instead, approximate formulae have been used by both the Medical Internal Radiation Dose committee (MIRD) and the ICRP due to the limitations imposed

  4. Application of the ICRP/ICRU reference computational phantoms to internal dosimetry: calculation of specific absorbed fractions of energy for photons and electrons

    NASA Astrophysics Data System (ADS)

    Hadid, L.; Desbrée, A.; Schlattl, H.; Franck, D.; Blanchardon, E.; Zankl, M.

    2010-07-01

    The emission of radiation from a contaminated body region is connected with the dose received by radiosensitive tissue through the specific absorbed fractions (SAFs) of emitted energy, which is therefore an essential quantity for internal dose assessment. A set of SAFs were calculated using the new adult reference computational phantoms, released by the International Commission on Radiological Protection (ICRP) together with the International Commission on Radiation Units and Measurements (ICRU). Part of these results has been recently published in ICRP Publication 110 (2009 Adult reference computational phantoms (Oxford: Elsevier)). In this paper, we mainly discuss the results and also present them in numeric form. The emission of monoenergetic photons and electrons with energies ranging from 10 keV to 10 MeV was simulated for three source organs: lungs, thyroid and liver. SAFs were calculated for four target regions in the body: lungs, colon wall, breasts and stomach wall. For quality assurance purposes, the simulations were performed simultaneously at the Helmholtz Zentrum München (HMGU, Germany) and at the Institute for Radiological Protection and Nuclear Safety (IRSN, France), using the Monte Carlo transport codes EGSnrc and MCNPX, respectively. The comparison of results shows overall agreement for photons and high-energy electrons with differences lower than 8%. Nevertheless, significant differences were found for electrons at lower energy for distant source/target organ pairs. Finally, the results for photons were compared to the SAF values derived using mathematical phantoms. Significant variations that can amount to 200% were found. The main reason for these differences is the change of geometry in the more realistic voxel body models. For electrons, no SAFs have been computed with the mathematical phantoms; instead, approximate formulae have been used by both the Medical Internal Radiation Dose committee (MIRD) and the ICRP due to the limitations imposed

  5. The MCART Radiation Physics Core: The Quest for Radiation Dosimetry Standardization

    PubMed Central

    Kazi, Abdul M.; MacVittie, Thomas J.; Lasio, Giovanni; Lu, Wei; Prado, Karl L.

    2013-01-01

    Dose-related radiobiological research results can only be meaningfully compared when radiation dosimetry is standardized. To this purpose, the National Institute of Allergy and Infectious Diseases (NIAID)-sponsored Medical Countermeasures Against Radiological Threats (MCART) consortium recently created a Radiation Physics Core (RPC) as an entity to assume responsibility of standardizing radiation dosimetry practices among its member laboratories. The animal research activities in these laboratories utilize a variety of ionizing photon beams from several irradiators such as 250–320 kVp x-ray generators, 137Cs irradiators, 60Co teletherapy machines, and medical linear accelerators (LINACs). In addition to this variety of sources, these centers utilize a range of irradiation techniques and make use of different dose calculation schemes to conduct their experiments. An extremely important objective in these research activities is to obtain a Dose Response Relationship (DRR) appropriate to their respective organ-specific models of acute and delayed radiation effects. A clear and unambiguous definition of the DRR is essential for the development of medical countermeasures. It is imperative that these DRRs are transparent between centers. The MCART RPC has initiated the establishment of standard dosimetry practices among member centers and is introducing a Remote Dosimetry Monitoring Service (RDMS) to ascertain ongoing quality assurance. In this paper we will describe the initial activities of the MCART RPC toward implementing these standardization goals. It is appropriate to report a summary of initial activities with the intent of reporting the full implementation at a later date. PMID:24276553

  6. Designing and Dosimetry of a Shield for Photon Fields of Radiation Therapy in Oral Cavity Cancer

    PubMed Central

    Jabbari, Keyvan; Senobari, Somayeh; Roayaei, Mahnaz; Rostampour, Masoumeh

    2015-01-01

    The cancer of oral cavity is related to lesions of mucous membrane of tongue and gum that can be treated with radiation therapy. A lateral photon field can be used to treat this kind of tumor, which has a side-effect on normal tissue in the opposite side of the oral cavity. In this study the dosimetric effect of the various shields in oral cavity is evaluated. In this study, a special phantom similar to the structure of oral cavity with capability of film dosimetry was designed and constructed. The various shield slabs were made of five materials: Lead, Plexiglas, Acrylic resin, Silicon and Plaster. For irradiation, Cobalt 60 (60Co) and 6 MV photon beams were used. The film dosimetry before and after the shield was performed using GAFCHROMIC EBT2 films. The film before the shield measures the magnitude of backscattering radiation from the shield. The prescribed dose was 150 cGy. Results showed that 3 cm of the lead in both energies had the maximum absorption of radiation. The absorbed dose to opposite side of shield for 6 MV photon beams and 60Co were 21 and 32 cGy, respectively. The minimum attenuation on radiation was observed in silicon shield for which the dose of opposite side were 116 and 147 cGy for 6 MV and 60Co respectively. The maximum backscattered dose was measured 177 cGy and 219 cGy using 3 cm thickness of lead, which was quite considerable. The minimum backscattering where for acrylic resin 101 and 118 cGy for 6 MV and cobalt. In this study, it was concluded that the amount of backscattering for 3 cm Lead shield is quite considerable and increases the dose significantly. A composite layer of shield with 1–2 cm lead and 1 cm acrylic resin can have the protective effect and low backscattering radiation at the same time. PMID:26120570

  7. Designing and Dosimetry of a Shield for Photon Fields of Radiation Therapy in Oral Cavity Cancer.

    PubMed

    Jabbari, Keyvan; Senobari, Somayeh; Roayaei, Mahnaz; Rostampour, Masoumeh

    2015-01-01

    The cancer of oral cavity is related to lesions of mucous membrane of tongue and gum that can be treated with radiation therapy. A lateral photon field can be used to treat this kind of tumor, which has a side-effect on normal tissue in the opposite side of the oral cavity. In this study the dosimetric effect of the various shields in oral cavity is evaluated. In this study, a special phantom similar to the structure of oral cavity with capability of film dosimetry was designed and constructed. The various shield slabs were made of five materials: Lead, Plexiglas, Acrylic resin, Silicon and Plaster. For irradiation, Cobalt 60 (60Co) and 6 MV photon beams were used. The film dosimetry before and after the shield was performed using GAFCHROMIC EBT2 films. The film before the shield measures the magnitude of backscattering radiation from the shield. The prescribed dose was 150 cGy. Results showed that 3 cm of the lead in both energies had the maximum absorption of radiation. The absorbed dose to opposite side of shield for 6 MV photon beams and 60Co were 21 and 32 cGy, respectively. The minimum attenuation on radiation was observed in silicon shield for which the dose of opposite side were 116 and 147 cGy for 6 MV and 60Co respectively. The maximum backscattered dose was measured 177 cGy and 219 cGy using 3 cm thickness of lead, which was quite considerable. The minimum backscattering where for acrylic resin 101 and 118 cGy for 6 MV and cobalt. In this study, it was concluded that the amount of backscattering for 3 cm Lead shield is quite considerable and increases the dose significantly. A composite layer of shield with 1-2 cm lead and 1 cm acrylic resin can have the protective effect and low backscattering radiation at the same time. PMID:26120570

  8. Bayesian Methods for Radiation Detection and Dosimetry

    SciTech Connect

    Peter G. Groer

    2002-09-29

    We performed work in three areas: radiation detection, external and internal radiation dosimetry. In radiation detection we developed Bayesian techniques to estimate the net activity of high and low activity radioactive samples. These techniques have the advantage that the remaining uncertainty about the net activity is described by probability densities. Graphs of the densities show the uncertainty in pictorial form. Figure 1 below demonstrates this point. We applied stochastic processes for a method to obtain Bayesian estimates of 222Rn-daughter products from observed counting rates. In external radiation dosimetry we studied and developed Bayesian methods to estimate radiation doses to an individual with radiation induced chromosome aberrations. We analyzed chromosome aberrations after exposure to gammas and neutrons and developed a method for dose-estimation after criticality accidents. The research in internal radiation dosimetry focused on parameter estimation for compartmental models from observed compartmental activities. From the estimated probability densities of the model parameters we were able to derive the densities for compartmental activities for a two compartment catenary model at different times. We also calculated the average activities and their standard deviation for a simple two compartment model.

  9. 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

  10. Three-dimensional personalized dosimetry for 188Re liver selective internal radiation therapy based on quantitative post-treatment SPECT studies

    NASA Astrophysics Data System (ADS)

    Shcherbinin, S.; Grimes, J.; Bator, A.; Cwikla, J. B.; Celler, A.

    2014-01-01

    We demonstrate that accurate patient-specific distributions of microspheres labeled with 188Re and resulting absorbed doses can be obtained from single-photon emission computed tomography (SPECT) studies performed after 188Re selective internal radiation therapy when accurate correction methods are employed in image reconstruction. Our quantitative image reconstruction algorithm includes corrections for attenuation, resolution degradations and scatter as well as a window-based compensation for contamination. The procedure has been validated using four phantom experiments containing an 18 ml cylindrical source (82-93 MBq of 188Re activity) simulating a liver tumor. In addition, we applied our approach to post-therapy SPECT studies of ten patients with progressive primary or metastatic liver carcinomas. Our quantitative algorithm accurately (within 9%) recovered 188Re activity from four phantom experiments. In addition, for two patients that received three scans, deviations remained consistent between the measured and the reconstructed activities that were determined from studies with differing severity of the dead-time effect. The analysis of absorbed doses for patient studies allowed us to hypothesize that D90 (the minimum dose received by 90% of the tumor volume) may be a reliable metric relating therapy outcomes to the calculated doses. Among several considered metrics, only D90 showed statistically significant correlation with the overall survival.

  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. Cluster pattern analysis of energy deposition sites for the brachytherapy sources 103Pd, 125I, 192Ir, 137Cs, and 60Co

    NASA Astrophysics Data System (ADS)

    Villegas, Fernanda; Tilly, Nina; Bäckström, Gloria; Ahnesjö, Anders

    2014-09-01

    Analysing the pattern of energy depositions may help elucidate differences in the severity of radiation-induced DNA strand breakage for different radiation qualities. It is often claimed that energy deposition (ED) sites from photon radiation form a uniform random pattern, but there is indication of differences in RBE values among different photon sources used in brachytherapy. The aim of this work is to analyse the spatial patterns of EDs from 103Pd, 125I, 192Ir, 137Cs sources commonly used in brachytherapy and a 60Co source as a reference radiation. The results suggest that there is both a non-uniform and a uniform random component to the frequency distribution of distances to the nearest neighbour ED. The closest neighbouring EDs show high spatial correlation for all investigated radiation qualities, whilst the uniform random component dominates for neighbours with longer distances for the three higher mean photon energy sources (192Ir, 137Cs, and 60Co). The two lower energy photon emitters (103Pd and 125I) present a very small uniform random component. The ratio of frequencies of clusters with respect to 60Co differs up to 15% for the lower energy sources and less than 2% for the higher energy sources when the maximum distance between each pair of EDs is 2 nm. At distances relevant to DNA damage, cluster patterns can be differentiated between the lower and higher energy sources. This may be part of the explanation to the reported difference in RBE values with initial DSB yields as an endpoint for these brachytherapy sources.

  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. 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.

  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. 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

  17. PET/CT-Based Dosimetry in 90Y-Microsphere Selective Internal Radiation Therapy: Single Cohort Comparison With Pretreatment Planning on 99mTc-MAA Imaging and Correlation With Treatment Efficacy

    PubMed Central

    Song, Yoo Sung; Paeng, Jin Chul; Kim, Hyo-Cheol; Chung, Jin Wook; Cheon, Gi Jeong; Chung, June-Key; Lee, Dong Soo; Kang, Keon Wook

    2015-01-01

    Abstract 90Y PET/CT can be acquired after 90Y-microsphere selective radiation internal therapy (SIRT) to describe radioactivity distribution. We performed dosimetry using 90Y-microsphere PET/CT data to evaluate treatment efficacy and appropriateness of activity planning from 99mTc-MAA scan and SPECT/CT. Twenty-three patients with liver malignancy were included in the study. 99mTc-MAA was injected during planning angiography and whole body 99mTc-MAA scan and liver SPECT/CT were acquired. After SIRT using 90Y-resin microsphere, 90Y-microsphere PET/CT was acquired. A partition model (PM) using 4 compartments (tumor, intarget normal liver, out-target normal liver, and lung) was adopted, and absorbed dose to each compartment was calculated based on measurements from 99mTc-MAA SPECT/CT and 90Y-microsphere PET/CT, respectively, to be compared with each other. Progression-free survival (PFS) was evaluated in terms of tumor absorbed doses calculated by 99mTc-MAA SPECT/CT and 90Y-microsphere PET/CT results. Lung shunt fraction was overestimated on 99mTc-MAA scan compared with 90Y-microsphere PET/CT (0.060 ± 0.037 vs. 0.018 ± 0.026, P < 0.01). Tumor absorbed dose exhibited a close correlation between the results from 99mTc-MAA SPECT/CT and 90Y-microsphere PET/CT (r = 0.64, P < 0.01), although the result from 99mTc-MAA SPECT/CT was significantly lower than that from 90Y-microsphere PET/CT (135.4 ± 64.2 Gy vs. 185.0 ± 87.8 Gy, P < 0.01). Absorbed dose to in-target normal liver was overestimated on 99mTc-MAA SPECT/CT compared with PET/CT (62.6 ± 38.2 Gy vs. 45.2 ± 32.0 Gy, P = 0.02). Absorbed dose to out-target normal liver did not differ between 99mTc-MAA SPECT/CT and 90Y-microsphere PET/CT (P = 0.49). Patients with tumor absorbed dose >200 Gy on 90Y-microsphere PET/CT had longer PFS than those with tumor absorbed dose ≤200 Gy (286 ± 56 days vs. 92 ± 20 days, P = 0.046). Tumor absorbed dose calculated by 99m

  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. Selected techniques in radioecology: Model development and comparison for internal dosimetry of rainbow trout (Oncorhynchus mykiss) and feasibiltiy assessment of reflectance spectroscopy use as a tool in phytoremediation

    NASA Astrophysics Data System (ADS)

    Martinez, Nicole

    The first study in Part 1 examines the effects of lake tropic structure on the uptake of iodine-131 (131I) in rainbow trout (Oncorhynchus mykiss) and considers a simple computational model for the estimation of resulting radiation dose. Iodine-131 is a major component of the atmospheric releases following reactor accidents, and the passage of 131I through food chains from grass to human thyroids has been extensively studied. By comparison, the fate and effects of 131I deposition onto lakes and other aquatic systems has been less studied. In this study we reanalyze 1960s data from experimental releases of 131I into two small lakes and compare the effects of differences in lake trophic structures on 131I accumulation in fish. The largest concentrations in the thyroids of trout may occur from 8 to 32 days post initial release. DCFs for trout for whole body as well as thyroid were computed using Monte Carlo modeling with an anatomically-appropriate model of trout thyroid structure. Activity concentration data was used in conjunction with the calculated DCFs to estimate dose rates and ultimately determine cumulative radiation dose (Gy) to the thyroids after 32 days. The estimated cumulative thyroid doses at 32 days post-release ranged from 6 mGy to 18 mGy per 1 Bq mL-1 of initial 131I in the water, depending upon fish size. The subsequent studies in Part 1 seek to develop and compare different, increasingly detailed anatomical phantoms for O. mykiss for the purpose of estimating organ radiation dose and dose rates from 131I uptake and from molybdenum-99 (99Mo) uptake. Model comparison and refinement is important to the process of determining both dose rates and dose effects, and we develop and compare three models for O. mykiss: a simplistic geometry considering a single organ, a more specific geometry employing anatomically relevant organ size and location, and voxel reconstruction of internal anatomy obtained from CT imaging (referred to as CSUTROUT). Dose Conversion

  20. Selected techniques in radioecology: Model development and comparison for internal dosimetry of rainbow trout (Oncorhynchus mykiss) and feasibiltiy assessment of reflectance spectroscopy use as a tool in phytoremediation

    NASA Astrophysics Data System (ADS)

    Martinez, Nicole

    The first study in Part 1 examines the effects of lake tropic structure on the uptake of iodine-131 (131I) in rainbow trout (Oncorhynchus mykiss) and considers a simple computational model for the estimation of resulting radiation dose. Iodine-131 is a major component of the atmospheric releases following reactor accidents, and the passage of 131I through food chains from grass to human thyroids has been extensively studied. By comparison, the fate and effects of 131I deposition onto lakes and other aquatic systems has been less studied. In this study we reanalyze 1960s data from experimental releases of 131I into two small lakes and compare the effects of differences in lake trophic structures on 131I accumulation in fish. The largest concentrations in the thyroids of trout may occur from 8 to 32 days post initial release. DCFs for trout for whole body as well as thyroid were computed using Monte Carlo modeling with an anatomically-appropriate model of trout thyroid structure. Activity concentration data was used in conjunction with the calculated DCFs to estimate dose rates and ultimately determine cumulative radiation dose (Gy) to the thyroids after 32 days. The estimated cumulative thyroid doses at 32 days post-release ranged from 6 mGy to 18 mGy per 1 Bq mL-1 of initial 131I in the water, depending upon fish size. The subsequent studies in Part 1 seek to develop and compare different, increasingly detailed anatomical phantoms for O. mykiss for the purpose of estimating organ radiation dose and dose rates from 131I uptake and from molybdenum-99 (99Mo) uptake. Model comparison and refinement is important to the process of determining both dose rates and dose effects, and we develop and compare three models for O. mykiss: a simplistic geometry considering a single organ, a more specific geometry employing anatomically relevant organ size and location, and voxel reconstruction of internal anatomy obtained from CT imaging (referred to as CSUTROUT). Dose Conversion

  1. Energy response of GR-200A thermoluminescence dosemeters to 60Co and to monoenergetic synchrotron radiation in the energy range 28-40 keV.

    PubMed

    Emiro, F; Di Lillo, F; Mettivier, G; Fedon, C; Longo, R; Tromba, G; Russo, P

    2016-01-01

    The response of LiF:Mg,Cu,P thermoluminescence dosemeters (type GR-200A) to monoenergetic radiation of energy 28, 35, 38 and 40 keV was evaluated with respect to irradiation with a calibrated (60)Co gamma-ray source. High-precision measurements of the relative air kerma response performed at the SYRMEP beamline of the ELETTRA synchrotron radiation facility (Trieste, Italy) showed a significant deviation of the average response to low-energy X-rays from that to (60)Co, with an over-response from 6 % (at 28 keV) to 22 % (at 40 keV). These data are not consistent with literature data for these dosemeters, where model predictions gave deviation from unity of the relative air kerma response of about 10 %. The authors conclude for the need of additional determinations of the low-energy relative response of GR-200A dosemeters, covering a wider range of monoenergetic energies sampled at a fine energy step, as planned in future experiments by their group at the ELETTRA facility. PMID:25737582

  2. Differential Expression of Retrotransposon WIS 2-1A Response to Vacuum, Low-Energy N+ Implantation and 60Coγ-ray Irradiation in Wheat

    NASA Astrophysics Data System (ADS)

    Zhao, Huiru; Gu, Yunhong; Ya, Huiyuan; Jiao, Zhen; Qin, Guangyong

    2009-02-01

    Mutagenesis and retrotransposons have a close relationship, but little attention has been paid yet to the activity of retrotransposons produced by physical mutagens. The variation of retrotransposon WIS 2-1A activity in wheat (Triticum aestivum L.) embryos at three different growth times (30 h, 45 h and 60 h) was investigated after they had been treated with N+ implantation in a vacuum of 5 × 10-2 Pa and irradiation by 60Coγ-ray respectively. For each of the three growth times the expression of WIS 2-1A showed almost entirely a same trend of downregulation, upregulation, then downregulation, and upregulation again with the increase in dose of N+ implantation, but the expression appeared irregular with the increase in irradiation of 60Coγ-ray. In conclusion, the acutely activating effect of WIS 2-1A stimulated by vacuum and high dose N+ implantation within a shorter incubation time may provide a convenient tool to advance the research on mutagenic breeding and function genes.

  3. Characterization of the Natural Organic Matter (NOM) in groundwater contaminated with (60)Co and (137)Cs using ultrafiltration, Solid Phase Extraction and fluorescence analysis.

    PubMed

    Caron, François; Siemann, Stefan; Riopel, Rémi

    2014-12-01

    Spot samples of shallow groundwaters have been taken between the years 2004 and 2010 near a site formerly used for the dispersal of radioactive liquid wastes. Three sampling points, one clean (upstream), and two downstream of the contamination source, were processed by ultrafiltration (5000 Da cut-off) and Solid Phase Extraction (SPE) to determine the association of selected artificial radionuclides ((60)Co, (137)Cs) with Natural Organic Matter (NOM). The last two sampling episodes (2008 and 2010) also benefited from fluorescence analysis to determine the major character of the NOM. The fluorescence signals are reported as humic-like, fulvic-like and protein-like, which are used to characterize the different NOM types. The NOM from the clean site comprised mostly fine material, whereas the colloidal content (retained by ultrafiltration) was higher (e.g., 15-40% of the Total Organic Carbon - TOC). Most of the 137Cs was present in the colloidal fraction, whereas (60)Co was found in the filtered fraction. Fluorescence analysis, on the other hand, indicated a contrasting behavior between the clean and contaminated sites, with a dominance of protein-like material, a feature usually associated with human impacts. Finally, SPE removed almost quantitatively the protein-like material (>90%), whereas it removed a much smaller fraction of the (137)Cs (<28%). This finding indicates that the (137)Cs preferential binding occurs with a fraction other than the protein-like NOM, likely the fulvic-like or humic-like portion. PMID:24476752

  4. A 3D superposition pencil beam dose calculation algorithm for a 60Co therapy unit and its verification by MC simulation

    NASA Astrophysics Data System (ADS)

    Koncek, O.; Krivonoska, J.

    2014-11-01

    The MCNP Monte Carlo code was used to simulate the collimating system of the 60Co therapy unit to calculate the primary and scattered photon fluences as well as the electron contamination incident to the isocentric plane as the functions of the irradiation field size. Furthermore, a Monte Carlo simulation for the polyenergetic Pencil Beam Kernels (PBKs) generation was performed using the calculated photon and electron spectra. The PBK was analytically fitted to speed up the dose calculation using the convolution technique in the homogeneous media. The quality of the PBK fit was verified by comparing the calculated and simulated 60Co broad beam profiles and depth dose curves in a homogeneous water medium. The inhomogeneity correction coefficients were derived from the PBK simulation of an inhomogeneous slab phantom consisting of various materials. The inhomogeneity calculation model is based on the changes in the PBK radial displacement and on the change of the forward and backward electron scattering. The inhomogeneity correction is derived from the electron density values gained from a complete 3D CT array and considers different electron densities through which the pencil beam is propagated as well as the electron density values located between the interaction point and the point of dose deposition. Important aspects and details of the algorithm implementation are also described in this study.

  5. Standard Practice for Dosimetry of Proton Beams for use in Radiation Effects Testing of Electronics

    SciTech Connect

    McMahan, Margaret A.; Blackmore, Ewart; Cascio, Ethan W.; Castaneda, Carlos; von Przewoski, Barbara; Eisen, Harvey

    2008-07-25

    Representatives of facilities that routinely deliver protons for radiation effect testing are collaborating to establish a set of standard best practices for proton dosimetry. These best practices will be submitted to the ASTM International for adoption.

  6. Reconstructive dosimetry for cutaneous radiation syndrome

    PubMed Central

    Lima, C.M.A.; Lima, A.R.; Degenhardt, Ä.L.; Valverde, N.J.; Da Silva, F.C.A.

    2015-01-01

    According to the International Atomic Energy Agency (IAEA), a relatively significant number of radiological accidents have occurred in recent years mainly because of the practices referred to as potentially high-risk activities, such as radiotherapy, large irradiators and industrial radiography, especially in gammagraphy assays. In some instances, severe injuries have occurred in exposed persons due to high radiation doses. In industrial radiography, 80 cases involving a total of 120 radiation workers, 110 members of the public including 12 deaths have been recorded up to 2014. Radiological accidents in industrial practices in Brazil have mainly resulted in development of cutaneous radiation syndrome (CRS) in hands and fingers. Brazilian data include 5 serious cases related to industrial gammagraphy, affecting 7 radiation workers and 19 members of the public; however, none of them were fatal. Some methods of reconstructive dosimetry have been used to estimate the radiation dose to assist in prescribing medical treatment. The type and development of cutaneous manifestations in the exposed areas of a person is the first achievable gross dose estimation. This review article presents the state-of-the-art reconstructive dosimetry methods enabling estimation of local radiation doses and provides guidelines for medical handling of the exposed individuals. The review also presents the Chilean and Brazilian radiological accident cases to highlight the importance of reconstructive dosimetry. PMID:26445332

  7. The Importance of Dosimetry Standardization in Radiobiology

    PubMed Central

    Desrosiers, Marc; DeWerd, Larry; Deye, James; Lindsay, Patricia; Murphy, Mark K; Mitch, Michael; Macchiarini, Francesca; Stojadinovic, Strahinja; Stone, Helen

    2013-01-01

    Radiation dose is central to much of radiobiological research. Precision and accuracy of dose measurements and reporting of the measurement details should be sufficient to allow the work to be interpreted and repeated and to allow valid comparisons to be made, both in the same laboratory and by other laboratories. Despite this, a careful reading of published manuscripts suggests that measurement and reporting of radiation dosimetry and setup for radiobiology research is frequently inadequate, thus undermining the reliability and reproducibility of the findings. To address these problems and propose a course of action, the National Cancer Institute (NCI), the National Institute of Allergy and Infectious Diseases (NIAID), and the National Institute of Standards and Technology (NIST) brought together representatives of the radiobiology and radiation physics communities in a workshop in September, 2011. The workshop participants arrived at a number of specific recommendations as enumerated in this paper and they expressed the desirability of creating dosimetry standard operating procedures (SOPs) for cell culture and for small and large animal experiments. It was also felt that these SOPs would be most useful if they are made widely available through mechanism(s) such as the web, where they can provide guidance to both radiobiologists and radiation physicists, be cited in publications, and be updated as the field and needs evolve. Other broad areas covered were the need for continuing education through tutorials at national conferences, and for journals to establish standards for reporting dosimetry. This workshop did not address issues of dosimetry for studies involving radiation focused at the sub-cellular level, internally-administered radionuclides, biodosimetry based on biological markers of radiation exposure, or dose reconstruction for epidemiological studies. PMID:26401441

  8. Design and operation of internal dosimetry programs

    SciTech Connect

    LaBone, T.R.

    1991-01-01

    The proposed revision to USNRC 10 CFR 20 and the USDOE Order 5480.11 require intakes of radioactive material to be evaluated. Radiation dose limits are based on the sum of effective dose equivalent from intakes and the whole body dose from external sources. These significant changes in the regulations will require, at a minimum, a complete review of personnel monitoring programs to determine their adequacy. In this session we will review a systematic method of designing a routine personnel monitoring program that will comply with the requirements of the new regulations. Specific questions discussed are: (a) What are the goals and objectives of a routine personnel monitoring program (b) When is a routine personnel monitoring program required (c) What are the required capabilities of the routine personnel monitoring program (d) What should be done with the information generated in a personnel monitoring program Specific recommendations and interpretations are given in the session. 5 refs., 3 figs., 33 tabs.

  9. Response of lithium formate EPR dosimeters at photon energies relevant to the dosimetry of brachytherapy

    SciTech Connect

    Adolfsson, Emelie; Alm Carlsson, Gudrun; Grindborg, Jan-Erik; Gustafsson, Haakan; Lund, Eva; Carlsson Tedgren, Aasa

    2010-09-15

    Purpose: To investigate experimentally the energy dependence of the detector response of lithium formate EPR dosimeters for photon energies below 1 MeV relative to that at {sup 60}Co energies. High energy photon beams are used in calibrating dosimeters for use in brachytherapy since the absorbed dose to water can be determined with high accuracy in such beams using calibrated ion chambers and standard dosimetry protocols. In addition to any differences in mass-energy absorption properties between water and detector, variations in radiation yield (detector response) with radiation quality, caused by differences in the density of ionization in the energy imparted (LET), may exist. Knowledge of an eventual deviation in detector response with photon energy is important for attaining high accuracy in measured brachytherapy dose distributions. Methods: Lithium formate EPR dosimeters were irradiated to known levels of air kerma in 25-250 kV x-ray beams and in {sup 137}Cs and {sup 60}Co beams at the Swedish Secondary Standards Dosimetry Laboratory. Conversions from air kerma free in air into values of mean absorbed dose to the detectors were made using EGSnrc MC simulations and x-ray energy spectra measured or calculated for the actual beams. The signals from the detectors were measured using EPR spectrometry. Detector response (the EPR signal per mean absorbed dose to the detector) relative to that for {sup 60}Co was determined for each beam quality. Results: Significant decreases in the relative response ranging from 5% to 6% were seen for x-ray beams at tube voltages {<=}180 kV. No significant reduction in the relative response was seen for {sup 137}Cs and 250 kV x rays. Conclusions: When calibrated in {sup 60}Co or MV photon beams, corrections for the photon energy dependence of detector response are needed to achieve the highest accuracy when using lithium formate EPR dosimeters for measuring absorbed doses around brachytherapy sources emitting photons in the energy

  10. Heavy-ion dosimetry

    SciTech Connect

    Schimmerling, W.

    1980-03-01

    This lecture deals with some of the more important physical characteristics of relativistic heavy ions and their measurement, with beam delivery and beam monitoring, and with conventional radiation dosimetry as used in the operation of the BEVALAC biomedical facility for high energy heavy ions (Lyman and Howard, 1977; BEVALAC, 1977). Even so, many fundamental aspects of the interaction of relativistic heavy ions with matter, including important atomic physics and radiation chemical considerations, are not discussed beyond the reminder that such additional understanding is required before an adequte perspective of the problem can be attained.

  11. Uranium Dispersion & Dosimetry Model.

    SciTech Connect

    MICHAEL,; MOMENI, H.

    2002-03-22

    The Uranium Dispersion and Dosimetry (UDAD) program provides estimates of potential radiation exposure to individuals and to the general population in the vicinity of a uranium processing facility such as a uranium mine or mill. Only transport through the air is considered. Exposure results from inhalation, external irradiation from airborne and ground-deposited activity, and ingestion of foodstuffs. Individual dose commitments, population dose commitments, and environmental dose commitments are computed. The program was developed for application to uranium mining and milling; however, it may be applied to dispersion of any other pollutant.

  12. Fast neutron dosimetry

    SciTech Connect

    DeLuca, P.M. Jr.; Pearson, D.W.

    1992-01-01

    This progress report concentrates on two major areas of dosimetry research: measurement of fast neutron kerma factors for several elements for monochromatic and white spectrum neutron fields and determination of the response of thermoluminescent phosphors to various ultra-soft X-ray energies and beta-rays. Dr. Zhixin Zhou from the Shanghai Institute of Radiation Medicine, People's Republic of China brought with him special expertise in the fabrication and use of ultra-thin TLD materials. Such materials are not available in the USA. The rather unique properties of these materials were investigated during this grant period.

  13. Uranium Dispersion & Dosimetry Model.

    Energy Science and Technology Software Center (ESTSC)

    2002-03-22

    The Uranium Dispersion and Dosimetry (UDAD) program provides estimates of potential radiation exposure to individuals and to the general population in the vicinity of a uranium processing facility such as a uranium mine or mill. Only transport through the air is considered. Exposure results from inhalation, external irradiation from airborne and ground-deposited activity, and ingestion of foodstuffs. Individual dose commitments, population dose commitments, and environmental dose commitments are computed. The program was developed for applicationmore » to uranium mining and milling; however, it may be applied to dispersion of any other pollutant.« less

  14. USF/Russian dosimetry on STS-57

    NASA Technical Reports Server (NTRS)

    1995-01-01

    The major purpose of this experiment was to conduct an international comparison of passive dosimetry methods in space. Two APD's were flown in the charged particle directional spectrometer (CPDS)/tissue equivalent proportional counter (TEPC) locker on the space shuttle during the STS-57 mission. Due to placement, the shielding and radiation environment of the APD's were nearly the same and the dosimeters distributed in the two boxes can be considered equally exposed. The dosimeter types included plastic nuclear track detectors (PNTD's), thermoluminescent detectors (TLD), nuclear emulsions, and thermal/resonance neutron detectors (TRND's). The USF dosimeters included PNTD's, TLD's, and TRND's, while the Russian dosimeters included PNTD's, TLD's, and nuclear emulsions.

  15. Third conference on radiation protection and dosimetry. Program and abstracts

    SciTech Connect

    Not Available

    1991-12-31

    This conference has been designed with the objectives of promoting communication among applied, research, regulatory, and standards personnel involved in radiation protection and providing them with sufficient information to evaluate their programs. To partly fulfill these objectives, a technical program consisting of more than 75 invited and contributed oral presentations encompassing all aspects of radiation protection has been prepared. General topics include external dosimetry, internal dosimetry, instruments, regulations and standards, accreditation and test programs, research advances, and applied program experience. This publication provides a summary of the technical program and a collection of abstracts of the oral presentations.

  16. Third conference on radiation protection and dosimetry. Program and abstracts

    SciTech Connect

    1991-01-01

    This conference has been designed with the objectives of promoting communication among applied, research, regulatory, and standards personnel involved in radiation protection and providing them with sufficient information to evaluate their programs. To partly fulfill these objectives, a technical program consisting of more than 75 invited and contributed oral presentations encompassing all aspects of radiation protection has been prepared. General topics include external dosimetry, internal dosimetry, instruments, regulations and standards, accreditation and test programs, research advances, and applied program experience. This publication provides a summary of the technical program and a collection of abstracts of the oral presentations.

  17. 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.

  18. Cross sections of the 57Fe(n,α)54Cr and 63Cu(n,α)60Co reactions in the MeV region

    NASA Astrophysics Data System (ADS)

    Gledenov, Yu. M.; Sedysheva, M. V.; Stolupin, V. A.; Zhang, Guohui; Han, Jinhua; Wang, Zhimin; Fan, Xiao; Liu, Xiang; Chen, Jinxiang; Khuukhenkhuu, G.; Szalanski, P. J.

    2014-06-01

    Cross sections of the 57Fe(n,α)54Cr reaction are measured for the first time, and those of the 63Cu(n,α)60Co reaction are measured in the megaelectron volt region by the direct experimental method. Experiments were performed at the 4.5-MV Van de Graaff Accelerator of Peking University. Monoenergetic neutrons (5.0, 5.5, 6.0, and 6.5 MeV) were produced through the 2H(d,n)3He reaction with a deuterium gas target. Measurements were carried out using a double-section-gridded ionization chamber and back-to-back double 57Fe and 63Cu samples. Foreground and background were measured in separate runs. A 238U sample and a BF3 long counter were utilized for absolute neutron flux calibration and for neutron flux normalization, respectively. Present results are compared with talys-1.4 code predictions, existing measurements, and evaluations.

  19. TOPICAL REVIEW: Polymer gel dosimetry

    NASA Astrophysics Data System (ADS)

    Baldock, C.; De Deene, Y.; Doran, S.; Ibbott, G.; Jirasek, A.; Lepage, M.; McAuley, K. B.; Oldham, M.; Schreiner, L. J.

    2010-03-01

    Polymer gel dosimeters are fabricated from radiation sensitive chemicals which, upon irradiation, polymerize as a function of the absorbed radiation dose. These gel dosimeters, with the capacity to uniquely record the radiation dose distribution in three-dimensions (3D), have specific advantages when compared to one-dimensional dosimeters, such as ion chambers, and two-dimensional dosimeters, such as film. These advantages are particularly significant in dosimetry situations where steep dose gradients exist such as in intensity-modulated radiation therapy (IMRT) and stereotactic radiosurgery. Polymer gel dosimeters also have specific advantages for brachytherapy dosimetry. Potential dosimetry applications include those for low-energy x-rays, high-linear energy transfer (LET) and proton therapy, radionuclide and boron capture neutron therapy dosimetries. These 3D dosimeters are radiologically soft-tissue equivalent with properties that may be modified depending on the application. The 3D radiation dose distribution in polymer gel dosimeters may be imaged using magnetic resonance imaging (MRI), optical-computerized tomography (optical-CT), x-ray CT or ultrasound. The fundamental science underpinning polymer gel dosimetry is reviewed along with the various evaluation techniques. Clinical dosimetry applications of polymer gel dosimetry are also presented.

  20. Topical Review: Polymer gel dosimetry

    PubMed Central

    Baldock, C; De Deene, Y; Doran, S; Ibbott, G; Jirasek, A; Lepage, M; McAuley, K B; Oldham, M; Schreiner, L J

    2010-01-01

    Polymer gel dosimeters are fabricated from radiation sensitive chemicals which, upon irradiation, polymerize as a function of the absorbed radiation dose. These gel dosimeters, with the capacity to uniquely record the radiation dose distribution in three-dimensions (3D), have specific advantages when compared to one-dimensional dosimeters, such as ion chambers, and two-dimensional dosimeters, such as film. These advantages are particularly significant in dosimetry situations where steep dose gradients exist such as in intensity-modulated radiation therapy (IMRT) and stereotactic radiosurgery. Polymer gel dosimeters also have specific advantages for brachytherapy dosimetry. Potential dosimetry applications include those for low-energy x-rays, high-linear energy transfer (LET) and proton therapy, radionuclide and boron capture neutron therapy dosimetries. These 3D dosimeters are radiologically soft-tissue equivalent with properties that may be modified depending on the application. The 3D radiation dose distribution in polymer gel dosimeters may be imaged using magnetic resonance imaging (MRI), optical-computerized tomography (optical-CT), x-ray CT or ultrasound. The fundamental science underpinning polymer gel dosimetry is reviewed along with the various evaluation techniques. Clinical dosimetry applications of polymer gel dosimetry are also presented. PMID:20150687

  1. EVA dosimetry in manned spacecraft.

    PubMed

    Thomson, I

    1999-12-01

    Extra Vehicular Activity (EVA) will become a large part of the astronaut's work on board the International Space Station (ISS). It is already well known that long duration space missions inside a spacecraft lead to radiation doses which are high enough to be a significant health risk to the crew. The doses received during EVA, however, have not been quantified to the same degree. This paper reviews the space radiation environment and the current dose limits to critical organs. Results of preliminary radiation dosimetry experiments on the external surface of the BION series of satellites indicate that EVA doses will vary considerably due to a number of factors such as EVA suit shielding, temporal fluctuations and spacecraft orbit and shielding. It is concluded that measurement of doses to crew members who engage in EVA should be done on board the spacecraft. An experiment is described which will lead the way to implementing this plan on the ISS. It is expected that results of this experiment will help future crew mitigate the risks of ionising radiation in space. PMID:10631334

  2. Gene expression-based dosimetry by dose and time in mice following acute radiation exposure.

    PubMed

    Tucker, James D; Divine, George W; Grever, William E; Thomas, Robert A; Joiner, Michael C; Smolinski, Joseph M; Auner, Gregory W

    2013-01-01

    Rapid and reliable methods for performing biological dosimetry are of paramount importance in the event of a large-scale nuclear event. Traditional dosimetry approaches lack the requisite rapid assessment capability, ease of use, portability and low cost, which are factors needed for triaging a large number of victims. Here we describe the results of experiments in which mice were acutely exposed to (60)Co gamma rays at doses of 0 (control) to 10 Gy. Blood was obtained from irradiated mice 0.5, 1, 2, 3, 5, and 7 days after exposure. mRNA expression levels of 106 selected genes were obtained by reverse-transcription real time PCR. Stepwise regression of dose received against individual gene transcript expression levels provided optimal dosimetry at each time point. The results indicate that only 4-7 different gene transcripts are needed to explain ≥ 0.69 of the variance (R(2)), and that receiver-operator characteristics, a measure of sensitivity and specificity, of ≥ 0.93 for these statistical models were achieved at each time point. These models provide an excellent description of the relationship between the actual and predicted doses up to 6 Gy. At doses of 8 and 10 Gy there appears to be saturation of the radiation-response signals with a corresponding diminution of accuracy. These results suggest that similar analyses in humans may be advantageous for use in a field-portable device designed to assess exposures in mass casualty situations. PMID:24358280

  3. Dose-effect relationships of nucleoplasmic bridges and complex nuclear anomalies in human peripheral lymphocytes exposed to 60Co γ-rays at a relatively low dose.

    PubMed

    Tian, Xue-Lei; Zhao, Hua; Cai, Tian-Jing; Lu, Xue; Chen, De-Qing; Li, Shuang; Liu, Qing-Jie

    2016-07-01

    The dose effect between nucleoplasmic bridges (NPB) and relatively low doses of ionising radiation remains unknown. Accordingly, this study investigated the NPB frequencies in human peripheral blood lymphocytes exposed to low-dose (60)Co γ-rays. Complex anomalies, including fused nuclei (FUS), horse-shoe nuclei (HS) and circular nuclei (CIR), which possibly originated from multiple NPBs, were also scored. Human peripheral blood samples were collected from three healthy males and irradiated with 0-1 and 0-0.4 Gy (60)Co γ-rays. A cytokinesis-block micronucleus cytome assay was then conducted to analyse NPB, PFHC (NPB plus three complex nuclear anomalies) and micronucleus (MN) in binucleated cells. All dose-response curves followed the linear model for both NPB frequency and PFHC cell frequency. The dose-response curves between NPB frequency and absorbed dose at 0-1 and 0-0.4 Gy were y = 0.0037x + 0.0005 (R (2) = 0.979, P < 0.05) and y = 0.0043x + 0.0004 (R (2) = 0.941, P < 0.05), respectively. The dose-response curves between PFHC cell frequency and absorbed dose at 0-1 and 0-0.4 Gy were y = 0.0044x + 0.0007 (R (2) = 0.982, P < 0.05) and y = 0.0059x + 0.0005 (R (2) = 0.969, P < 0.05), respectively. The statistical significance of differences between the irradiated groups (0-0.4 Gy) and background levels of NPB, PFHC and MN were also analysed. The lowest analysable doses of NPB, PFHC and MN were 0.12, 0.08 and 0.08 Gy, respectively. In conclusion, NPBs and PFHC positively correlated with the absorbed radiation at a relatively low dose. PMID:26833100

  4. Determination of the intrinsic energy dependence of LiF:Mg,Ti thermoluminescent dosimeters for {sup 125}I and {sup 103}Pd brachytherapy sources relative to {sup 60}Co

    SciTech Connect

    Reed, J. L. Micka, J. A.; Culberson, W. S.; DeWerd, L. A.; Rasmussen, B. E.; Davis, S. D.

    2014-12-15

    Purpose: To determine the intrinsic energy dependence of LiF:Mg,Ti thermoluminescent dosimeters (TLD-100) for {sup 125}I and {sup 103}Pd brachytherapy sources relative to {sup 60}Co. Methods: LiF:Mg,Ti TLDs were irradiated with low-energy brachytherapy sources and with a {sup 60}Co teletherapy source. The brachytherapy sources measured were the Best 2301 {sup 125}I seed, the OncoSeed 6711 {sup 125}I seed, and the Best 2335 {sup 103}Pd seed. The TLD light output per measured air-kerma strength was determined for the brachytherapy source irradiations, and the TLD light output per air kerma was determined for the {sup 60}Co irradiations. Monte Carlo (MC) simulations were used to calculate the dose-to-TLD rate per air-kerma strength for the brachytherapy source irradiations and the dose to TLD per air kerma for the {sup 60}Co irradiations. The measured and MC-calculated results for all irradiations were used to determine the TLD intrinsic energy dependence for {sup 125}I and {sup 103}Pd relative to {sup 60}Co. Results: The relative TLD intrinsic energy dependences (relative to {sup 60}Co) and associated uncertainties (k = 1) were determined to be 0.883 ± 1.3%, 0.870 ± 1.4%, and 0.871 ± 1.5% for the Best 2301 seed, OncoSeed 6711 seed, and Best 2335 seed, respectively. Conclusions: The intrinsic energy dependence of TLD-100 is dependent on photon energy, exhibiting changes of 13%–15% for {sup 125}I and {sup 103}Pd sources relative to {sup 60}Co. TLD measurements of absolute dose around {sup 125}I and {sup 103}Pd brachytherapy sources should explicitly account for the relative TLD intrinsic energy dependence in order to improve dosimetric accuracy.

  5. Breast dosimetry in clinical mammography

    NASA Astrophysics Data System (ADS)

    Benevides, Luis Alberto Do Rego

    The objective of this study was show that a clinical dosimetry protocol that utilizes a dosimetric breast phantom series based on population anthropometric measurements can reliably predict the average glandular dose (AGD) imparted to the patient during a routine screening mammogram. In the study, AGD was calculated using entrance skin exposure and dose conversion factors based on fibroglandular content, compressed breast thickness, mammography unit parameters and modifying parameters for homogeneous phantom (phantom factor), compressed breast lateral dimensions (volume factor) and anatomical features (anatomical factor). The protocol proposes the use of a fiber-optic coupled (FOCD) or Metal Oxide Semiconductor Field Effect Transistor (MOSFET) dosimeter to measure the entrance skin exposure at the time of the mammogram without interfering with diagnostic information of the mammogram. The study showed that FOCD had sensitivity with less than 7% energy dependence, linear in all tube current-time product stations, and was reproducible within 2%. FOCD was superior to MOSFET dosimeter in sensitivity, reusability, and reproducibility. The patient fibroglandular content was evaluated using a calibrated modified breast tissue equivalent homogeneous phantom series (BRTES-MOD) designed from anthropomorphic measurements of a screening mammography population and whose elemental composition was referenced to International Commission on Radiation Units and Measurements Report 44 tissues. The patient fibroglandular content, compressed breast thickness along with unit parameters and spectrum half-value layer were used to derive the currently used dose conversion factor (DgN). The study showed that the use of a homogeneous phantom, patient compressed breast lateral dimensions and patient anatomical features can affect AGD by as much as 12%, 3% and 1%, respectively. The protocol was found to be superior to existing methodologies. In addition, the study population anthropometric

  6. Relationship between student selection criteria and learner success for medical dosimetry students.

    PubMed

    Baker, Jamie; Tucker, Debra; Raynes, Edilberto; Aitken, Florence; Allen, Pamela

    2016-01-01

    Medical dosimetry education occupies a specialized branch of allied health higher education. Noted international shortages of health care workers, reduced university funding, limitations on faculty staffing, trends in learner attrition, and increased enrollment of nontraditional students force medical dosimetry educational leadership to reevaluate current admission practices. Program officials wish to select medical dosimetry students with the best chances of successful graduation. The purpose of the quantitative ex post facto correlation study was to investigate the relationship between applicant characteristics (cumulative undergraduate grade point average (GPA), science grade point average (SGPA), prior experience as a radiation therapist, and previous academic degrees) and the successful completion of a medical dosimetry program, as measured by graduation. A key finding from the quantitative study was the statistically significant positive correlation between a student׳s previous degree and his or her successful graduation from the medical dosimetry program. Future research investigations could include a larger research sample, representative of more medical dosimetry student populations, and additional studies concerning the relationship of previous work as a radiation therapist and the effect on success as a medical dosimetry student. Based on the quantitative correlation analysis, medical dosimetry leadership on admissions committees could revise student selection rubrics to place less emphasis on an applicant׳s undergraduate cumulative GPA and increase the weight assigned to previous degrees. PMID:26553474

  7. Radioembolization Dosimetry: The Road Ahead

    SciTech Connect

    Smits, Maarten L. J. Elschot, Mattijs; Sze, Daniel Y.; Kao, Yung H.; Nijsen, Johannes F. W.; Iagaru, Andre H.; Jong, Hugo W. A. M. de; Bosch, Maurice A. A. J. van den; Lam, Marnix G. E. H.

    2015-04-15

    Methods for calculating the activity to be administered during yttrium-90 radioembolization (RE) are largely based on empirical toxicity and efficacy analyses, rather than dosimetry. At the same time, it is recognized that treatment planning based on proper dosimetry is of vital importance for the optimization of the results of RE. The heterogeneous and often clustered intrahepatic biodistribution of millions of point-source radioactive particles poses a challenge for dosimetry. Several studies found a relationship between absorbed doses and treatment outcome, with regard to both toxicity and efficacy. This should ultimately lead to improved patient selection and individualized treatment planning. New calculation methods and imaging techniques and a new generation of microspheres for image-guided RE will all contribute to these improvements. The aim of this review is to give insight into the latest and most important developments in RE dosimetry and to suggest future directions on patient selection, individualized treatment planning, and study designs.

  8. Fundamentals of Radiation Dosimetry

    SciTech Connect

    Bos, Adrie J. J.

    2011-05-05

    The basic concepts of radiation dosimetry are reviewed on basis of ICRU reports and text books. The radiation field is described with, among others, the particle fluence. Cross sections for indirectly ionizing radiation are defined and indicated is how they are related to the mass energy transfer and mass energy absorption coefficients. Definitions of total and restricted mass stopping powers of directly ionizing radiation are given. The dosimetric quantities, kerma, absorbed dose and exposure together with the relations between them are discussed in depth. Finally it is indicated how the absorbed dose can be measured with a calorimeter by measuring the temperature increase and with an ionisation chamber measuring the charge produced by the ionizing radiation and making use of the Bragg-Gray relation.

  9. Fundamentals of Radiation Dosimetry

    NASA Astrophysics Data System (ADS)

    Bos, Adrie J. J.

    2011-05-01

    The basic concepts of radiation dosimetry are reviewed on basis of ICRU reports and text books. The radiation field is described with, among others, the particle fluence. Cross sections for indirectly ionizing radiation are defined and indicated is how they are related to the mass energy transfer and mass energy absorption coefficients. Definitions of total and restricted mass stopping powers of directly ionizing radiation are given. The dosimetric quantities, kerma, absorbed dose and exposure together with the relations between them are discussed in depth. Finally it is indicated how the absorbed dose can be measured with a calorimeter by measuring the temperature increase and with an ionisation chamber measuring the charge produced by the ionizing radiation and making use of the Bragg-Gray relation.

  10. The spatial resolution in dosimetry with normoxic polymer-gels investigated with the dose modulation transfer approach

    SciTech Connect

    Bayreder, Christian; Schoen, Robert; Wieland, M.; Georg, Dietmar; Moser, Ewald; Berg, Andreas

    2008-05-15

    The verification of dose distributions with high dose gradients as appearing in brachytherapy or stereotactic radiotherapy for example, calls for dosimetric methods with sufficiently high spatial resolution. Polymer gels in combination with a MR or optical scanner as a readout device have the potential of performing the verification of a three-dimensional dose distribution within a single measurement. The purpose of this work is to investigate the spatial resolution achievable in MR-based polymer gel dosimetry. The authors show that dosimetry on a very small spatial scale (voxel size: 94x94x1000 {mu}m{sup 3}) can be performed with normoxic polymer gels using parameter selective T2 imaging. In order to prove the spatial resolution obtained we are relying on the dose-modulation transfer function (DMTF) concept based on very fine dose modulations at half periods of 200 {mu}m. Very fine periodic dose modulations of a {sup 60}Co photon field were achieved by means of an absorption grid made of tungsten-carbide, specifically designed for quality control. The dose modulation in the polymer gel is compared with that of film dosimetry in one plane via the DMTF concept for general access to the spatial resolution of a dose imaging system. Additionally Monte Carlo simulations were performed and used for the calculation of the DMTF of both, the polymer gel and film dosimetry. The results obtained by film dosimetry agree well with those of Monte Carlo simulations, whereas polymer gel dosimetry overestimates the amplitude value of the fine dose modulations. The authors discuss possible reasons. The in-plane resolution achieved in this work competes with the spatial resolution of standard clinical film-scanner systems.

  11. Dissolution rate and radiation dosimetry of metal tritides

    SciTech Connect

    Cheng, Y.

    1993-12-31

    Metal tritides including titanium tritide (Ti{sup 3}H{sub x}) and erbium tritide (Er{sup 3}H{sub x}) have been used as components of neutron generators. These compounds can be released to the air as aerosols during fabrication, assembling, and testing of components or in accidental or fugitive releases; as a result, workers may be exposed to these compounds by inhalation. A joint research project between Sandia National Laboratories and the Inhalation Toxicology Research Institute was initiated to investigate the solubility of metal tritide particles, to determine retention and translocation of inhaled particles in animals, and to develop an internal dosimetry model. The current understanding of metal tritides and their radiation dosimetry for internal exposure is very limited. The ICRP Report 30 does not provide for tritium dosimetry in metal tritide form. The current radiation protection guidelines for metal tritide particles are based on the assumption that the biological behavior is similar to tritiated water which could be easily absorbed into body fluid, and therefore, a relatively short biological half life (10 days). If the solubility is low, the biological half life of metal tritide particles and the dosimetry of inhalation exposure to these particles could be quite different from tritiated water. This would have significant implications in the current health protection guidelines including annual limits of intakes and derived air concentrations. The preliminary results of our metal tritide dissolution study indicated that the solubility of titanium tritide is low.

  12. Lyoluminescence dosimetry in photon and fast neutron beams.

    PubMed

    Puite, K J; Crebolder, D L

    1977-11-01

    The lyoluminescence (LL) technique using mannose, a monosaccharide, is described. Dose-response curves for 60Co-gamma-rays (5 rad to 120 krad), fission neutrons, 5.3 MeV and 15 MeV neutrons (100 rad to 20 krad) have been measured. The close tissue-equivalence of mannose makes this material well suited for dosimetric use in low energy X-ray fields for radiotherapy and radiobiology. It also provides a cheap, simple and reproducible dosemeter in industrial applications of radiation (sprouting inhibition of onions and potatoes; control of insect infestation). After correction for the gamma contamination of the neutron beam the LL signal per rad in ICRU muscle tissue from the neutron irradiations has been derived and the relative effectiveness of the LL signal for fast neutrons in mannose has been calculated as 0.34 +/- 0.03 (fission neutrons), 0.63 +/- 0.07 (5.3 MeV neutrons) and 0.74 +/- 0.05 (15 MeV neutrons). These results are compared with data from other systems. It is concluded that mannose can be used as a transfer system in neutron dosimetry, if its variation in sensitivity with neutron energy is taken into account. PMID:594143

  13. DyF 3: A promising new TL material for gamma dosimetry

    NASA Astrophysics Data System (ADS)

    Soliman, C.

    2009-07-01

    This research describes preliminary investigation of some radiation dosimetry characteristics of commercial dysprosium fluoride powder. The as-received aliquot has strong thermoluminescence (TL) emission with one sharp peak at ˜234 °C. The TL characteristics have been examined under excitation of gamma (γ) doses in the range 1 Gy-50 kGy from a 60Co gamma source. The dose response was linear up to 100 Gy and a sub-linear response was observed at higher doses. The TL signal is observed to remain stable for aliquots irradiated to γ-doses in the range 1-10 Gy over one month storage period in dark at ambient temperature and humidity conditions. This paper recommends using DyF 3 in doping of TL materials which may be promising for future dosimeter development.

  14. ESR response of phenol compounds for dosimetry of gamma photon beams

    NASA Astrophysics Data System (ADS)

    Marrale, M.; Longo, A.; Panzeca, S.; Gallo, S.; Principato, F.; Tomarchio, E.; Parlato, A.; Buttafava, A.; Dondi, D.; Zeffiro, A.

    2014-11-01

    In the present paper we investigate the features of IRGANOX® 1076 phenols as a material for electron spin resonance (ESR) dosimetry. We experimentally analyzed the ESR response of pellets of IRGANOX® 1076 phenols irradiated with 60Co photons. The best experimental parameters (modulation amplitude and microwave power) for dosimetric applications have been obtained. The dependence of ESR signal as function of γ dose is found to be linear in the dose range studied (12-60 Gy) and the lowest measurable dose is found to be of the order of 1 Gy. The signal after irradiation is very stable in the first thirty days. From the point of view of the tissue equivalence, these materials have mass energy absorption coefficient values comparable with those of soft tissue.

  15. Reactor Dosimetry State of the Art 2008

    NASA Astrophysics Data System (ADS)

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

    2009-08-01

    Oral session 1: Retrospective dosimetry. Retrospective dosimetry of VVER 440 reactor pressure vessel at the 3rd unit of Dukovany NPP / M. Marek ... [et al.]. Retrospective dosimetry study at the RPV of NPP Greifswald unit 1 / J. Konheiser ... [et al.]. Test of prototype detector for retrospective neutron dosimetry of reactor internals and vessel / K. Hayashi ... [et al.]. Neutron doses to the concrete vessel and tendons of a magnox reactor using retrospective dosimetry / D. A. Allen ... [et al.]. A retrospective dosimetry feasibility study for Atucha I / J. Wagemans ... [et al.]. Retrospective reactor dosimetry with zirconium alloy samples in a PWR / L. R. Greenwood and J. P. Foster -- Oral session 2: Experimental techniques. Characterizing the Time-dependent components of reactor n/y environments / P. J. Griffin, S. M. Luker and A. J. Suo-Anttila. Measurements of the recoil-ion response of silicon carbide detectors to fast neutrons / F. H. Ruddy, J. G. Seidel and F. Franceschini. Measurement of the neutron spectrum of the HB-4 cold source at the high flux isotope reactor at Oak Ridge National Laboratory / J. L. Robertson and E. B. Iverson. Feasibility of cavity ring-down laser spectroscopy for dose rate monitoring on nuclear reactor / H. Tomita ... [et al.]. Measuring transistor damage factors in a non-stable defect environment / D. B. King ... [et al.]. Neutron-detection based monitoring of void effects in boiling water reactors / J. Loberg ... [et al.] -- Poster session 1: Power reactor surveillance, retrospective dosimetry, benchmarks and inter-comparisons, adjustment methods, experimental techniques, transport calculations. Improved diagnostics for analysis of a reactor pulse radiation environment / S. M. Luker ... [et al.]. Simulation of the response of silicon carbide fast neutron detectors / F. Franceschini, F. H. Ruddy and B. Petrović. NSV A-3: a computer code for least-squares adjustment of neutron spectra and measured dosimeter responses / J. G

  16. Synthesis, photoluminescence, thermoluminescence and dosimetry properties of novel phosphor Zn(BO2)2:Tb

    NASA Astrophysics Data System (ADS)

    Li, J.; Zhang, C. X.; Tang, Q.; Zhang, Y. L.; Hao, J. Q.; Su, Q.; Wang, S. B.

    2007-02-01

    Polycrystalline powder samples of terbium doped Zn(BO2)2 phosphors were prepared by solid state reaction in the thermal carbon reducing atmosphere at high temperature. The photoluminescence (PL), three-dimensional (3D) TL emission spectrum and dosimetric characteristics following 60Co gamma-rays irradiation were studied. Characteristic emission bands of Tb3+ at about 490, 543, 584 and 620 nm, attributed to the 5D4→7FJ (J=3, 4, 5, 6) transitions of Tb3+ ions, were observed in the TL and PL emission spectrum. No emission from Tb4+ ions was observed in the TL emission spectrum. The TL-dose response of the powder samples Zn(BO2)2:Tb to 60Co gamma-rays radiation in the dose range from 1 to 100 Gy for clinical dose levels was almost linear. The experiment results showed that Zn(BO2)2:Tb has potential use as the materials of gamma-rays thermoluminescence dosimeter (TLD) for clinical dosimetry.

  17. 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.

  18. 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.

  19. Intrinsic dosimetry. Properties and mechanisms of thermoluminescence in commercial borosilicate glass

    SciTech Connect

    Clark, Richard A.

    2012-10-01

    Intrinsic dosimetry is the method of measuring total absorbed dose received by the walls of a container holding radioactive material. By considering the total absorbed dose received by a container in tandem with the physical characteristics of the radioactive material housed within that container, this method has the potential to provide enhanced pathway information regarding the history of the container and its radioactive contents. The latest in a series of experiments designed to validate and demonstrate this newly developed tool are reported. Thermoluminescence (TL) dosimetry was used to measure dose effects on raw stock borosilicate container glass up to 70 days after gamma ray, x-ray, beta particle or ultraviolet irradiations at doses from 0.15 to 20 Gy. The TL glow curve when irradiated with 60Co was separated into five peaks: two relatively unstable peaks centered near 120 and 165°C, and three relatively stable peaks centered near 225, 285, and 360°C. Depending on the borosilicate glass source, the minimum measurable dose using this technique is 0.15-0.5 Gy, which is roughly equivalent to a 24 hr irradiation at 1 cm from a 50-165 ng source of 60Co. Differences in TL glow curve shape and intensity were observed for the glasses from different geographical origins. These differences can be explained by changes in the intensities of the five peaks. Electron paramagnetic resonance (EPR) and multivariate statistical methods were used to relate the TL intensity and peaks to electron/hole traps and compositional variations.

  20. Magnetic removal of electron contamination for 60Co panoramic gamma ray exposure--Investigations with CaSO4:Dy and LiF based dosimeters.

    PubMed

    Kumar, Munish; Sahani, G; Chourasiya, G

    2010-06-01

    Electron contamination from a sealed (60)Co radiation source has been investigated comprehensively using a CaSO(4):Dy based TLD badge and LiF crystals. It has been found that due to electron contamination, the thermoluminescence (TL) detectors exhibit over response which can be corrected by applying a magnetic field. It has also been found that for a source-to-dosimeter distance of 50 cm, the ratio of the TL readouts of the third to first discs of the TLD badge reduces from approximately 1.5 to approximately 1.00 after applying a magnetic field. Hence detectors which are sensitive to electrons as well as photons, and are capable of distinguishing them, can lead to an erroneous measurement. This happens because the contribution due to electron contamination interferes with pure gamma calibration. The study is helpful in establishing accurate calibration and appropriate correction factors for personnel monitoring carried out using CaSO(4):Dy based TLD badge. PMID:20071190

  1. Optimization of process parameters for the inactivation of Lactobacillus sporogenes in tomato paste with ultrasound and 60Co- γ irradiation using response surface methodology

    NASA Astrophysics Data System (ADS)

    Ye, Sheng-Ying; Qiu, Yuan-Xin; Song, Xian-Liang; Luo, Shu-Can

    2009-03-01

    The processing parameters for ultrasound and 60Co- γ irradiation were optimized for their ability to inactivate Lactobacillus sporogenes in tomato paste using a systematic experimental design based on response surface methodology. Ultrasonic power, ultrasonic processing time and irradiation dose were explored and a central composite rotation design was adopted as the experimental plan, and a least-squares regression model was obtained. The significant influential factors for the inactivation rate of L. sporogenes were obtained from the quadratic model and the t-test analyses for each process parameter. Confirmation of the experimental results indicated that the proposed model was reasonably accurate and could be used to describe the efficacy of the treatments for inactivating L. sporogenes within the limits of the factors studied. The optimized processing parameters were found to be an ultrasonic power of 120 W with a processing time of 25 min and an irradiation dose of 6.5 kGy. These were measured under the constraints of parameter limitation, based on the Monte Carlo searching method and the quadratic model of the response surface methodology, including the a/ b value of the Hunter color scale of tomato paste. Nevertheless, the ultrasound treatment prior to irradiation for the inactivation of L. sporogenes in tomato paste was unsuitable for reducing the irradiation dose.

  2. Space radiation dosimetry

    SciTech Connect

    Hanser, F.A.; Dichter, B.K. ||

    1993-12-31

    Dosimetry is the measurement of the energy deposited in matter by various forms of radiation. In space the radiation is primarily energetic electrons, protons and heavier ions from planetary radiation belts, solar flares, and interstellar cosmic rays. Experimentally, dose is frequently obtained by summing the individual energy deposits in a solid state detector. If the detector is calibrated and the sensitive mass is known, the energy sum can be converted directly to accumulated radiation dose in Gy (J/kg). Such detectors can also be used to provide an approximate separation of dose into the components due to electrons, protons, and heavier ions, which is useful if it is desired to convert the measured dose into a biological effective dose (Sv) for manned spaceflight purposes. The output can also be used to provide an essentially instantaneous dose rate for use as warning devices. This is the primary type of space radiation dosimeter to be discussed here. The MOS-type dosimeter is another solid state sensor which can be of small size and low power. These devices integrate the total dose once through, can not separate particle types, and are not suitable for instantaneous dose rate measurement at low levels. There are several additional methods of measuring space radiation dose using scintillators, etc., but are not discussed in detail. In this paper emphasis is given to descriptions of active solid state detector instruments which have successfully worked in space. Some results of in-orbit dose measurements are presented.

  3. 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

  4. 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)

  5. Clinical radionuclide therapy dosimetry: the quest for the “Holy Gray”

    PubMed Central

    Bodei, L.; Giammarile, F.; Linden, O.; Luster, M.; Oyen, W. J. G.; Tennvall, J.

    2007-01-01

    Introduction Radionuclide therapy has distinct similarities to, but also profound differences from external radiotherapy. Review This review discusses techniques and results of previously developed dosimetry methods in thyroid carcinoma, neuro-endocrine tumours, solid tumours and lymphoma. In each case, emphasis is placed on the level of evidence and practical applicability. Although dosimetry has been of enormous value in the preclinical phase of radiopharmaceutical development, its clinical use to optimise administered activity on an individual patient basis has been less evident. In phase I and II trials, dosimetry may be considered an inherent part of therapy to establish the maximum tolerated dose and dose–response relationship. To prove that dosimetry-based radionuclide therapy is of additional benefit over fixed dosing or dosing per kilogram body weight, prospective randomised phase III trials with appropriate end points have to be undertaken. Data in the literature which underscore the potential of dosimetry to avoid under- and overdosing and to standardise radionuclide therapy methods internationally are very scarce. Developments In each section, particular developments and insights into these therapies are related to opportunities for dosimetry. The recent developments in PET and PET/CT imaging, including micro-devices for animal research, and molecular medicine provide major challenges for innovative therapy and dosimetry techniques. Furthermore, the increasing scientific interest in the radiobiological features specific to radionuclide therapy will advance our ability to administer this treatment modality optimally. PMID:17268773

  6. Methods and computer readable medium for improved radiotherapy dosimetry planning

    DOEpatents

    Wessol, Daniel E.; Frandsen, Michael W.; Wheeler, Floyd J.; Nigg, David W.

    2005-11-15

    Methods and computer readable media are disclosed for ultimately developing a dosimetry plan for a treatment volume irradiated during radiation therapy with a radiation source concentrated internally within a patient or incident from an external beam. The dosimetry plan is available in near "real-time" because of the novel geometric model construction of the treatment volume which in turn allows for rapid calculations to be performed for simulated movements of particles along particle tracks therethrough. The particles are exemplary representations of alpha, beta or gamma emissions emanating from an internal radiation source during various radiotherapies, such as brachytherapy or targeted radionuclide therapy, or they are exemplary representations of high-energy photons, electrons, protons or other ionizing particles incident on the treatment volume from an external source. In a preferred embodiment, a medical image of a treatment volume irradiated during radiotherapy having a plurality of pixels of information is obtained.

  7. a New ENDF/B-VII.0 Based Multigroup Cross-Section Library for Reactor Dosimetry

    NASA Astrophysics Data System (ADS)

    Alpan, F. A.; Anderson, S. L.

    2009-08-01

    The latest of the ENDF/B libraries, ENDF/B-VII.0 was released in December 2006. In this paper, the ENDF/B-VII.O evaluations were used in generating a new coupled neutron/gamma multigroup library having the same group structure of VITAMIN-B6, i.e., the 199-neutron, 42-gamma group library. The new library was generated utilizing NJOY99.259 for pre-processing and the AMPX modules for post-processing of cross sections. An ENDF/B-VI.3 based VITAMIN-B6-like library was also generated. The fine-group libraries and the ENDF/B-VI.3 based 47-neutron, 20-gamma group BUGLE-96 library were used with the discrete ordinates code DORT to obtain a three-dimensional synthesized flux distribution from r, r-θ, and r-z models for a standard Westinghouse 3-loop design reactor. Reaction rates were calculated for ex-vessel neutron dosimetry containing 63Cu(n,α)60Co, 46Ti(n,p)46Sc, 54Fe(n,P)54Mn, 58Ni(n,P)58Co, 238U(n,f)137Cs, 237Np(n,f)137Cs, and 59Co(n,γ)60Co (bare and cadmium covered) reactions. Results were compared to measurements. In comparing the 199-neutron, 42-gamma group ENDF/B-VI.3 and ENDF/B-VII.O libraries, it was observed that the ENDF/B-VI.3 based library results were in better agreement with measurements. There is a maximum difference of 7% (for the 63Cu(n,α)60Co reaction rate calculation) between ENDF/B-VI.3 and ENDF/B-VII.O. Differences between ENDF/B-VI.3 and ENDF/B-VII.O libraries are due to 16O, 1H, 90Zr, 91Zr, 92Zr, 238U, and 239Pu evaluations. Both ENDF/B-VI.3 and ENDF/B-VII.O library calculated reaction rates are within 20% of measurement and meet the criterion specified in the U. S. Nuclear Regulatory Commission Regulatory Guide 1.190, "Calculational and Dosimetry Methods for Determining Pressure Vessel Neutron Fluence."

  8. Fourth Personnel Dosimetry Intercomparison Study

    SciTech Connect

    Dickson, H.W.

    1980-02-01

    The fourth Personnel Dosimetry Intercomparison Study was held at the Oak Ridge National Laboratory's Dosimetry Applications Research Facility during March 15-23, 1978. The Health Physics Research Reactor (HPRR) used unshielded, with a 12-cm-thick Lucite shield, a 20-cm-thick concrete shield, or a 5-cm-thick steel and 15-cm-thick concrete shield, and provided four neutron and gamma-ray spectra. Then the dose was calculated based on the HPRR neutron spectra and dose conversion factors which had been determined previously for the four spectra. The results of these personnel dosimetry intercomparison studies reveal that estimates of dose equivalent vary over a wide range. The standard deviation of the mean of participants data for gamma measurements was in the range of 29 to 43%; for neutrons it was 57 to 188%. (PCS)

  9. In vivo dosimetry with silicon diodes in total body irradiation

    NASA Astrophysics Data System (ADS)

    Oliveira, F. F.; Amaral, L. L.; Costa, A. M.; Netto, T. G.

    2014-02-01

    The aim of this work is the characterization and application of silicon diode detectors for in vivo dosimetry in total body irradiation (TBI) treatments. It was evaluated the diode response with temperature, dose rate, gantry angulations and field size. A maximum response variation of 2.2% was obtained for temperature dependence. The response variation for dose rate and angular was within 1.2%. For field size dependence, the detector response increased with field until reach a saturation region, where no more primary radiation beam contributes for dose. The calibration was performed in a TBI setup. Different lateral thicknesses from one patient were simulated and then the calibration factors were determined by means of maximum depth dose readings. Subsequent to calibration, in vivo dosimetry measurements were performed. The response difference between diode readings and the prescribed dose for all treatments was below 4%. This difference is in agreement as recommended by the International Commission on Radiation Units and Measurements (ICRU), which is ±5%. The present work to test the applicability of a silicon diode dosimetry system for performing in vivo dose measurements in TBI techniques presented good results. These measurements demonstrated the value of diode dosimetry as a treatment verification method and its applicability as a part of a quality assurance program in TBI treatments.

  10. Consecutive C[subscript 60] Fullerene Dissociation from Ir([eta][superscript 2]-C[subscript 60])(CO)(Cl)(PPh[subscript 3])[subscript 2] and the Oxidative Addition of Benzene

    ERIC Educational Resources Information Center

    Felix, Tamara; Cortes-Figueroa, Jose E.

    2010-01-01

    This laboratory activity is a mechanistic exploration of the interactions between electronically deficient organometallic compounds and solvent molecules. Simple kinetics experiments designed to explore the mechanism of C[subscript 60] fullerene-benzene exchange on Ir(([eta][superscript 2]-C[subscript 60])(CO)(Cl)(PPh[subscript 3])[subscript 2]…

  11. Freeware for reporting radiation dosimetry following the administration of radiopharmaceuticals.

    PubMed

    Gómez Perales, Jesús Luis; García Mendoza, Antonio

    2015-09-01

    This work describes the development of a software application for reporting patient radiation dosimetry following radiopharmaceutical administration. The resulting report may be included within the patient's medical records. The application was developed in the Visual Basic programming language. The dosimetric calculations are based on the values given by the International Commission on Radiological Protection (ICRP). The software is available in both Spanish and English and can be downloaded at no cost from www.radiopharmacy.net. PMID:26092354

  12. 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.

  13. Monte Carlo portal dosimetry

    SciTech Connect

    Chin, P.W. . E-mail: mary.chin@physics.org

    2005-10-15

    This project developed a solution for verifying external photon beam radiotherapy. The solution is based on a calibration chain for deriving portal dose maps from acquired portal images, and a calculation framework for predicting portal dose maps. Quantitative comparison between acquired and predicted portal dose maps accomplishes both geometric (patient positioning with respect to the beam) and dosimetric (two-dimensional fluence distribution of the beam) verifications. A disagreement would indicate that beam delivery had not been according to plan. The solution addresses the clinical need for verifying radiotherapy both pretreatment (without the patient in the beam) and on treatment (with the patient in the beam). Medical linear accelerators mounted with electronic portal imaging devices (EPIDs) were used to acquire portal images. Two types of EPIDs were investigated: the amorphous silicon (a-Si) and the scanning liquid ion chamber (SLIC). The EGSnrc family of Monte Carlo codes were used to predict portal dose maps by computer simulation of radiation transport in the beam-phantom-EPID configuration. Monte Carlo simulations have been implemented on several levels of high throughput computing (HTC), including the grid, to reduce computation time. The solution has been tested across the entire clinical range of gantry angle, beam size (5 cmx5 cm to 20 cmx20 cm), and beam-patient and patient-EPID separations (4 to 38 cm). In these tests of known beam-phantom-EPID configurations, agreement between acquired and predicted portal dose profiles was consistently within 2% of the central axis value. This Monte Carlo portal dosimetry solution therefore achieved combined versatility, accuracy, and speed not readily achievable by other techniques.

  14. [Protective effects of WR2721 on early bone marrow hematopoietic function in mice exposed to 6.5 Gy of (60)Co γ-rays].

    PubMed

    Deng, Zi-Liang; Zhang, Liu-Zhen; Cong, Yue; Liu, Xiao-Lan; Yu, Zu-Ying; Shan, Ya-Jun; Cui, Yu; Wang, Li-Mei; Xing, Shuang; Cong, Yu-Wen; Luo, Qing-Liang

    2014-06-01

    The aim of this study was to investigate the effect of WR2721(amifostine) against bone marrow hematopoietic damage of mice exposed to 6.5 Gy of (60)Co-γ ray. A total of 60 C57/BL6J mice was divided into 3 groups:normal group (mice were injected with physiological salt solution), irradiation group (mice were injected with physiologic salt solution before irradiation) and WR2721 group (mice were injected with WR2721 before irradiation). The WBC, neutrophil (Neut), Plt and RBC levels in peripheral blood of 3 group mice were counted within 60 days after irradiation; the bone marrow nuclear cells (BMNC) were counted at 2 and 24 hours after irradiation; the hematopoietic stem/progenitor cell (LK/LSK) level and colony formation capability were detected by flow cytometry at 2 and 24 hours after irradiation. The results indicated that the counts of WBC and neut at 4 and 18 days, Plt at 7-18 days and RBC at 10-30 day after irradiation in WR2721 group were higher than those in irradiation group (P < 0.05); the BMNC, LSK and LK levels obviously increased at 24 hours after irradiation (P < 0.05), the CFU-GEMM, CFU-GM, CFU-MK BFU-E and CFU-E all significantly increased at 2 and 24 hours after irradiation (P < 0.01), as compared with irradiation group. It is concluded that WR2721 can effectively alleviate early hematopoietic damage and promote the fast recovery of peripheral blood cells in mice exposed to γ-ray, suggesting that the WR2721 has significant radioprotective effect on hematopoietic system. PMID:24989296

  15. Calibration of helical tomotherapy machine using EPR/alanine dosimetry

    SciTech Connect

    Perichon, Nicolas; Garcia, Tristan; Francois, Pascal; Lourenco, Valerie; Lesven, Caroline; Bordy, Jean-Marc

    2011-03-15

    Purpose: Current codes of practice for clinical reference dosimetry of high-energy photon beams in conventional radiotherapy recommend using a 10x10 cm{sup 2} square field, with the detector at a reference depth of 10 cm in water and 100 cm source to surface distance (SSD) (AAPM TG-51) or 100 cm source-to-axis distance (SAD) (IAEA TRS-398). However, the maximum field size of a helical tomotherapy (HT) machine is 40x5 cm{sup 2} defined at 85 cm SAD. These nonstandard conditions prevent a direct implementation of these protocols. The purpose of this study is twofold: To check the absorbed dose in water and dose rate calibration of a tomotherapy unit as well as the accuracy of the tomotherapy treatment planning system (TPS) calculations for a specific test case. Method: Both topics are based on the use of electron paramagnetic resonance (EPR) using alanine as transfer dosimeter between the Laboratoire National Henri Becquerel (LNHB) {sup 60}Co-{gamma}-ray reference beam and the Institut Curie's HT beam. Irradiations performed in the LNHB reference {sup 60}Co-{gamma}-ray beam allowed setting up the calibration method, which was then implemented and tested at the LNHB 6 MV linac x-ray beam, resulting in a deviation of 1.6% (at a 1% standard uncertainty) relative to the reference value determined with the standard IAEA TRS-398 protocol. Results: HT beam dose rate estimation shows a difference of 2% with the value stated by the manufacturer at a 2% standard uncertainty. A 4% deviation between measured dose and the calculation from the tomotherapy TPS was found. The latter was originated by an inadequate representation of the phantom CT-scan values and, consequently, mass densities within the phantom. This difference has been explained by the mass density values given by the CT-scan and used by the TPS which were not the true ones. Once corrected using Monte Carlo N-Particle simulations to validate the accuracy of this process, the difference between corrected TPS

  16. Sorption of {sup 60}Co, {sup 85}Sr, {sup 137}Cs, {sup 237}Np and {sup 241}Am on soil under coexistence of humic acid: Effects of molecular size of humic acid

    SciTech Connect

    Tanaka, Tadao; Senoo, Muneaki

    1995-12-31

    Sorption experiments have been performed by a batch method, to study the effects of humic acid of different molecular size on the complexing stability with {sup 60}Co, {sup 85}Sr, {sup 137}Cs, {sup 237}Np and {sup 241}Am, and on the sorption behavior of these radionuclides on a sandy soil. Equilibrium constants K in the sorption of {sup 137}Cs and {sup 237}Np onto the soil were not changed at different concentrations of humic acid since {sup 137}Cs and {sup 237}Np do not interact with humic acid, while those of {sup 60}Co and {sup 241}Am decreased with increasing humic acid concentration due to forming humic complexes. However, the K of {sup 85}Sr was not changed at different humic acid concentrations, despite {sup 85}Sr interacts with humic acid. This contradiction was probably caused from that a main binding of {sup 85}Sr with humic acid is not based on coordination bond but electrostatic force, due to relatively high concentration of non-radioactive strontium. The theoretical sorption model taking account of the interaction of {sup 60}Co and {sup 241}Am with humic acid could well reproduce the values of K for each radionuclide at different concentrations of humic acid. Concentration profiles of the radionuclides in each size fraction of the solution before and after the sorption experiments were examined by ultrafiltration technique. The reduction of concentration of {sup 60}Co in the fraction less than 300,000 of cutoff molecular weight (MW) and that of concentration of {sup 241}Am in the fraction larger than 100,000MW, respectively, by the sorption onto the soil decreased with increasing humic acid concentration. This decrease resulted in the decrease in the K of {sup 60}Co and {sup 241}Am with increasing humic acid concentration.

  17. Alleviation of pre-exposure of mouse brain with low-dose 12C6+ ion or 60Co gamma-ray on male reproductive endocrine damages induced by subsequent high-dose irradiation.

    PubMed

    Zhang, Hong; Liu, Bing; Zhou, Qingming; Zhou, Guangming; Yuan, Zhigang; Li, Wenjian; Duan, Xin; Min, Fengling; Xie, Yi; Li, Xiaoda

    2006-12-01

    Irradiation has been widely reported to damage organisms by attacking on proteins, nucleic acid and lipids in cells. However, radiation hormesis after low-dose irradiation has become the focus of research in radiobiology in recent years. To investigate the effects of pre-exposure of mouse brain with low-dose (12)C6+ ion or 60Co gamma (gamma)-ray on male reproductive endocrine capacity induced by subsequent high-dose irradiation, the brains of the B6C3F1 hybrid strain male mice were irradiated with 0.05 Gy of (12)C6+ ion or 60Co gamma-ray as the pre-exposure dose, and were then irradiated with 2 Gy as challenging irradiation dose at 4 h after pre-exposure. Serum pituitary gonadotropin hormones, follicle-stimulating hormone (FSH) and luteinizing hormone (LH), testosterone, testis weight, sperm count and shape were measured on the 35th day after irradiation. The results showed that there was a significant reduction in the levels of serum FSH, LH, testosterone, testis weight and sperm count, and a significant increase in sperm abnormalities by irradiation of the mouse brain with 2 Gy of (12)C6+ ion or 60Co gamma-ray. Moreover, the effects were more obvious in the group irradiated by (12)C6+ ion than in that irradiated by 60Co gamma-ray. Pre-exposure with low-dose (12)C6+ ion or 60Co gamma-ray significantly alleviated the harmful effects induced by a subsequent high-dose irradiation. PMID:17121657

  18. Tissue substitutes in radiation dosimetry and measurement

    SciTech Connect

    Not Available

    1989-01-01

    This book explains the activities of the International Commission on Radiation Units and Measurements and discusses tissue substitutes in radiation dosimetry and measurement. The following section is on basic concepts including definitions, specifications, and interaction coefficients. This section also includes a description of the effects of photons, electrons, neutrons, and heavily charged particles on body tissues. The third section is on selected requirements for tissue substitutes and briefly covers radiation-related requirements for radiation therapy, radiologic diagnosis, radiation protection, and radiobiology. The fourth short section is on composition of body tissues, and comparative interaction and depth dose data for selected tissue substitutes are covered in the fifth section. This includes several tables and many graphs of the ratios required to calculate the radiation dose.

  19. 36Cl measurements in Hiroshima granite samples as part of an international intercomparison study. Results from the Munich group.

    PubMed

    Huber, T; Rühm, W; Hoshi, M; Egbert, S D; Nolte, E

    2003-04-01

    Within the effort to resolve the so-called Hiroshima neutron discrepancy, an international intercomparison study has been carried out on granite samples from Hiroshima, with participating institutions from Japan, the US, and Germany. (36)Cl and (152)Eu produced in these samples by thermal neutrons from the A-bomb explosion were assessed independently by means of different techniques. At the Maier-Leibnitz-Laboratory near Munich, Germany, (36)Cl concentrations were measured by accelerator mass spectrometry. Measured (36)Cl/Cl ratios ranged from 1,670 x 10(-13) (at a distance of 146 m from the hypocenter) to 2.2 x 10(-13) (at a distance of 1,163 m from the hypocenter). One granite sample not exposed to A-bomb neutrons was measured as a control, and a (36)Cl/Cl ratio of 2.6 x 10(-13) was obtained. On average, our experimental results are 20-30% lower than those provided by model calculations based on the dosimetry system DS86. The results presented here do not support previous assessments of (36)Cl, (60)Co, and (152)Eu which had suggested much larger thermal neutron fluences than those calculated on the basis of DS86 for distances from the hypocenter of more than 1,000 m. PMID:12684827

  20. SU-E-T-102: Determination of Dose Distributions and Water-Equivalence of MAGIC-F Polymer Gel for 60Co and 192Ir Brachytherapy Sources

    SciTech Connect

    Quevedo, A; Nicolucci, P

    2014-06-01

    Purpose: Analyse the water-equivalence of MAGIC-f polymer gel for {sup 60}Co and {sup 192}Ir clinical brachytherapy sources, through dose distributions simulated with PENELOPE Monte Carlo code. Methods: The real geometry of {sup 60} (BEBIG, modelo Co0.A86) and {sup 192}192Ir (Varian, model GammaMed Plus) clinical brachytherapy sources were modelled on PENELOPE Monte Carlo simulation code. The most probable emission lines of photons were used for both sources: 17 emission lines for {sup 192}Ir and 12 lines for {sup 60}. The dose distributions were obtained in a cubic water or gel homogeneous phantom (30 × 30 × 30 cm{sup 3}), with the source positioned in the middle of the phantom. In all cases the number of simulation showers remained constant at 10{sup 9} particles. A specific material for gel was constructed in PENELOPE using weight fraction components of MAGIC-f: wH = 0,1062, wC = 0,0751, wN = 0,0139, wO = 0,8021, wS = 2,58×10{sup −6} e wCu = 5,08 × 10{sup −6}. The voxel size in the dose distributions was 0.6 mm. Dose distribution maps on the longitudinal and radial direction through the centre of the source were used to analyse the water-equivalence of MAGIC-f. Results: For the {sup 60} source, the maximum diferences in relative doses obtained in the gel and water were 0,65% and 1,90%, for radial and longitudinal direction, respectively. For {sup 192}Ir, the maximum difereces in relative doses were 0,30% and 1,05%, for radial and longitudinal direction, respectively. The materials equivalence can also be verified through the effective atomic number and density of each material: Zef-MAGIC-f = 7,07 e .MAGIC-f = 1,060 g/cm{sup 3} and Zef-water = 7,22. Conclusion: The results showed that MAGIC-f is water equivalent, consequently being suitable to simulate soft tissue, for Cobalt and Iridium energies. Hence, gel can be used as a dosimeter in clinical applications. Further investigation to its use in a clinical protocol is needed.

  1. Dosimetric comparison between the microSelectron HDR 192Ir v2 source and the BEBIG 60Co source for HDR brachytherapy using the EGSnrc Monte Carlo transport code

    PubMed Central

    Islam, M. Anwarul; Akramuzzaman, M. M.; Zakaria, G. A.

    2012-01-01

    Manufacturing of miniaturized high activity 192Ir sources have been made a market preference in modern brachytherapy. The smaller dimensions of the sources are flexible for smaller diameter of the applicators and it is also suitable for interstitial implants. Presently, miniaturized 60Co HDR sources have been made available with identical dimensions to those of 192Ir sources. 60Co sources have an advantage of longer half life while comparing with 192Ir source. High dose rate brachytherapy sources with longer half life are logically pragmatic solution for developing country in economic point of view. This study is aimed to compare the TG-43U1 dosimetric parameters for new BEBIG 60Co HDR and new microSelectron 192Ir HDR sources. Dosimetric parameters are calculated using EGSnrc-based Monte Carlo simulation code accordance with the AAPM TG-43 formalism for microSlectron HDR 192Ir v2 and new BEBIG 60Co HDR sources. Air-kerma strength per unit source activity, calculated in dry air are 9.698×10-8 ± 0.55% U Bq-1 and 3.039×10-7 ± 0.41% U Bq-1 for the above mentioned two sources, respectively. The calculated dose rate constants per unit air-kerma strength in water medium are 1.116±0.12% cGy h-1U-1 and 1.097±0.12% cGy h-1U-1, respectively, for the two sources. The values of radial dose function for distances up to 1 cm and more than 22 cm for BEBIG 60Co HDR source are higher than that of other source. The anisotropic values are sharply increased to the longitudinal sides of the BEBIG 60Co source and the rise is comparatively sharper than that of the other source. Tissue dependence of the absorbed dose has been investigated with vacuum phantom for breast, compact bone, blood, lung, thyroid, soft tissue, testis, and muscle. No significant variation is noted at 5 cm of radial distance in this regard while comparing the two sources except for lung tissues. The true dose rates are calculated with considering photon as well as electron transport using appropriate cut

  2. Patient-specific quality assurance for the delivery of 60Co intensity modulated radiation therapy subject to a 0.35 T lateral magnetic field

    PubMed Central

    Li, H. Harold; Rodriguez, Vivian L.; Green, Olga L.; Hu, Yanle; Kashani, Rojano; Wooten, H. Omar; Yang, Deshan; Mutic, Sasa

    2014-01-01

    Purpose This work describes a patient-specific dosimetry quality assurance (QA) program for intensity modulated radiation therapy (IMRT) using ViewRay, the first commercial magnetic resonance imaging guided radiation therapy device. Methods and materials The program consisted of the following components: 1) one-dimensional multipoint ionization chamber measurement using a customized 15 cm3 cubic phantom, 2) two-dimensional (2D) radiographic film measurement using a 30×30×20 cm3 phantom with multiple inserted ionization chambers, 3) quasi- three-dimensional (3D) diode array (ArcCHECK) measurement with a centrally inserted ionization chamber, 4) 2D fluence verification using machine delivery log files, and 5) 3D Monte-Carlo (MC) dose reconstruction with machine delivery files and phantom CT. Results The ionization chamber measurements agreed well with treatment planning system (TPS) computed doses in all phantom geometries where the mean difference (mean ± SD) was 0.0% ± 1.3% (n=102, range, −3.0 % to 2.9%). The film measurements also showed excellent agreement with the TPS computed 2D dose distributions where the mean passing rate using 3% relative/3 mm gamma criteria was 94.6% ± 3.4% (n=30, range, 87.4% to 100%). For ArcCHECK measurements, the mean passing rate using 3% relative/3 mm gamma criteria was 98.9% ± 1.1% (n=34, range, 95.8% to 100%). 2D fluence maps with a resolution of 1×1 mm2 showed 100% passing rates for all plan deliveries (n=34). The MC reconstructed doses to the phantom agreed well with planned 3D doses where the mean passing rate using 3% absolute/3 mm gamma criteria was 99.0% ± 1.0% (n=18, range, 97.0% to100%), demonstrating the feasibility of evaluating the QA results in the patient geometry. Conclusions We have developed a dosimetry program for ViewRay’s patient-specific IMRT QA. The methodology will be useful for other ViewRay users. The QA results presented here can assist the RT community to establish appropriate tolerance and

  3. Patient-Specific Quality Assurance for the Delivery of {sup 60}Co Intensity Modulated Radiation Therapy Subject to a 0.35-T Lateral Magnetic Field

    SciTech Connect

    Li, H. Harold Rodriguez, Vivian L.; Green, Olga L.; Hu, Yanle; Kashani, Rojano; Wooten, H. Omar; Yang, Deshan; Mutic, Sasa

    2015-01-01

    Purpose: This work describes a patient-specific dosimetry quality assurance (QA) program for intensity modulated radiation therapy (IMRT) using ViewRay, the first commercial magnetic resonance imaging-guided RT device. Methods and Materials: The program consisted of: (1) a 1-dimensional multipoint ionization chamber measurement using a customized 15-cm{sup 3} cube-shaped phantom; (2) 2-dimensional (2D) radiographic film measurement using a 30- × 30- × 20-cm{sup 3} phantom with multiple inserted ionization chambers; (3) quasi-3D diode array (ArcCHECK) measurement with a centrally inserted ionization chamber; (4) 2D fluence verification using machine delivery log files; and (5) 3D Monte Carlo (MC) dose reconstruction with machine delivery files and phantom CT. Results: Ionization chamber measurements agreed well with treatment planning system (TPS)-computed doses in all phantom geometries where the mean ± SD difference was 0.0% ± 1.3% (n=102; range, −3.0%-2.9%). Film measurements also showed excellent agreement with the TPS-computed 2D dose distributions where the mean passing rate using 3% relative/3 mm gamma criteria was 94.6% ± 3.4% (n=30; range, 87.4%-100%). For ArcCHECK measurements, the mean ± SD passing rate using 3% relative/3 mm gamma criteria was 98.9% ± 1.1% (n=34; range, 95.8%-100%). 2D fluence maps with a resolution of 1 × 1 mm{sup 2} showed 100% passing rates for all plan deliveries (n=34). The MC reconstructed doses to the phantom agreed well with planned 3D doses where the mean passing rate using 3% absolute/3 mm gamma criteria was 99.0% ± 1.0% (n=18; range, 97.0%-100%), demonstrating the feasibility of evaluating the QA results in the patient geometry. Conclusions: We developed a dosimetry program for ViewRay's patient-specific IMRT QA. The methodology will be useful for other ViewRay users. The QA results presented here can assist the RT community to establish appropriate tolerance and action limits for View

  4. Intercomparison of personal dosimetry for service providers in Pakistan.

    PubMed

    Jabeen, Akhter; Salman, Syed Ahmad

    2009-02-01

    An intercomparison exercise for personal dosimetry service providers within Pakistan was conducted by the Health Physics Division of the Pakistan Institute of Nuclear Science and Technology. Participation in the exercise was on voluntary basis. The exercise was carried out to harmonize individual dose monitoring techniques for high energy photons in terms of a new operational quantity, namely personal dose equivalent Hp(10), for personal dosimetry in accordance with the recommendations of the International Commission on Radiation Units and Measurements. Each laboratory submitted 25 dosimeters for participation in the intercomparison exercise. Protection level Co and Cs sources were used for irradiation of dosimeters on a water phantom according to International Atomic Energy Agency protocol at the Secondary Standard Dosimetry Laboratory. Hp(10) doses for five different dose levels were measured by the participating laboratories. The ratios of measured dose/true dose (Hm/Ht) remained in the range of 0.66 to 1.11 for the Co source and 0.84 to 1.17 for the Cs source. Performance of service providers' laboratories to measure Hp(10) doses was analyzed and evaluated in terms of trumpet curves plotted for photons at a 95% confidence level. PMID:19125056

  5. Dosimetry of Radiopharmaceuticals for Diagnostic and Therapeutic Nuclear Medicine

    SciTech Connect

    Smart, Richard

    2011-05-05

    A standard formalism for radionuclide internal radiation dosimetry was developed in the 1960s and continues to be refined today. Early work was based on a mathematical phantom but this is being replaced by phantoms developed from whole-body CT scans to give more realistic dose estimates. The largest contributors to the uncertainties in these dose estimates are the errors associated with in vivo activity quantitation, the variability of the biokinetics between patients and the limited information that can be obtained on these kinetics in individual patients. Despite these limitations, pre-treatment patient-specific dosimetry is being increasing used, particularly to limit the toxicity to non-target organs such as the bone marrow.

  6. Dosimetry of Radiopharmaceuticals for Diagnostic and Therapeutic Nuclear Medicine

    NASA Astrophysics Data System (ADS)

    Smart, Richard

    2011-05-01

    A standard formalism for radionuclide internal radiation dosimetry was developed in the 1960s and continues to be refined today. Early work was based on a mathematical phantom but this is being replaced by phantoms developed from whole-body CT scans to give more realistic dose estimates. The largest contributors to the uncertainties in these dose estimates are the errors associated with in vivo activity quantitation, the variability of the biokinetics between patients and the limited information that can be obtained on these kinetics in individual patients. Despite these limitations, pre-treatment patient-specific dosimetry is being increasing used, particularly to limit the toxicity to non-target organs such as the bone marrow.

  7. EPR dosimetry in a mixed neutron and gamma radiation field.

    PubMed

    Trompier, F; Fattibene, P; Tikunov, D; Bartolotta, A; Carosi, A; Doca, M C

    2004-01-01

    Suitability of Electron Paramagnetic Resonance (EPR) spectroscopy for criticality dosimetry was evaluated for tooth enamel, mannose and alanine pellets during the 'international intercomparison of criticality dosimetry techniques' at the SILENE reactor held in Valduc in June 2002, France. These three materials were irradiated in neutron and gamma-ray fields of various relative intensities and spectral distributions in order to evaluate their neutron sensitivity. The neutron response was found to be around 10% for tooth enamel, 45% for mannose and between 40 and 90% for alanine pellets according their type. According to the IAEA recommendations on the early estimate of criticality accident absorbed dose, analyzed results show the EPR potentiality and complementarity with regular criticality techniques. PMID:15353687

  8. 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.

  9. A new technique for dosimetry reaction cross-section evaluation

    SciTech Connect

    Badikov, S.A.

    2011-07-01

    Document available in abstract form only, full text of document follows: An objective of this paper is a unification of the procedure for dosimetry reaction cross-section evaluation. A set of requirements for the unified evaluation procedure is presented. A new code (ORTHO) was developed in order to meet these requirements. A statistical model, an algorithm, and the basic formulae employed in the code are described. The code was used for Ti48(n,p) reaction cross-section evaluation. The results of the evaluation are compared to International Reactor Dosimetry File (IRDF)-2002 data. The evaluated cross-sections and their correlations from this work are in good agreement with the IRDF-2002 evaluated data, whereas the uncertainties of the evaluated cross-sections are inconsistent. (authors)

  10. Development of silicon monolithic arrays for dosimetry in external beam radiotherapy

    NASA Astrophysics Data System (ADS)

    Bisello, Francesca; Menichelli, David; Scaringella, Monica; Talamonti, Cinzia; Zani, Margherita; Bucciolini, Marta; Bruzzi, Mara

    2015-10-01

    New tools for dosimetry in external beam radiotherapy have been developed during last years in the framework of the collaboration among the University of Florence, INFN Florence and IBA Dosimetry. The first step (in 2007) was the introduction in dosimetry of detector solutions adopted from high energy physics, namely epitaxial silicon as the base detector material and a guard ring in diode design. This allowed obtaining state of the art radiation hardness, in terms of sensitivity dependence on accumulated dose, with sensor geometry particularly suitable for the production of monolithic arrays with modular design. Following this study, a 2D monolithic array has been developed, based on 6.3×6.3 cm2 modules with 3 mm pixel pitch. This prototype has been widely investigated and turned out to be a promising tool to measure dose distributions of small and IMRT fields. A further linear array prototype has been recently design with improve spatial resolution (1 mm pitch) and radiation hardness. This 24 cm long device is constituted by 4×64 mm long modules. It features low sensitivity changes with dose (0.2%/kGy) and dose per pulse (±1% in the range 0.1-2.3 mGy/pulse, covering applications with flattened and unflattened photon fields). The detector has been tested with very satisfactory results as a tool for quality assurance of linear accelerators, with special regards to small fields, and proton pencil beams. In this contribution, the characterization of the linear array with unflattened MV X-rays, 60Co radiation and 226 MeV protons is reported.

  11. Unexplained overexposures on physical dosimetry reported by biological dosimetry.

    PubMed

    Montoro, A; Almonacid, M; Villaescusa, J I; Verdu, G

    2009-01-01

    The Medical Service of the Radiation Protection Service from the University Hospital La Fe (Valencia, Spain), carries out medical examinations of the workers occupationally exposed to ionising radiation. The Biological Dosimetry Laboratory is developing its activity since 2001. Up to now, the activities have been focused in performing biological dosimetry studies of Interventionists workers from La Fe Hospital. Recently, the Laboratory has been authorized by the Health Authority in the Valencian Community. Unexplained overexposures of workers and patients are also studied. Workers suspected of being overexposed to ionising radiation were referred for investigation by cytogenetic analysis. Two of these were from Hospitals of the Valencian Community and one belonged to an uranium mine from Portugal. Hospital workers had a physical dose by thermoluminiscence dosimeters (TLD) that exceeded the established limit. The worker of the uranium mine received a dose from a lost source of Cesium 137 with an activity of 170 mCi. All three cases showed normal values after the hematological analysis. Finally, the aim of this study consist to determine whether the dose showed by the dosimeter is reliable or not. In the case of workers that wore dosimeter, it is concluded that the doses measured by dosimeter are not corresponding to real doses. Hospital worker with a physical dose of 2.6 Sv and 0.269 Sv had an estimated absorbed dose by biological dosimetry of 0.076 Gy (0-0.165 Gy) and 0 Gy (0-0.089 Gy), respectively. In case of the mine worker an estimated absorbed dose of 0.073 Gy (0-0.159 Gy) was obtained by biological dosimetry. In all cases we used the odds ratio to present the results due to a very low frequency of observed aberrations [1]. PMID:19964943

  12. Dissolution rate and radiation dosimetry of metal tritides

    SciTech Connect

    Jow, Hong-Nian; Cheng, Yung-Sung

    1993-06-01

    Metal tritides including titanium tritide (Ti{sup 3}H{sub x}) and erbium tritide (Er{sup 3}H{sub x}) have been used as components of neutron generators. These compounds can be released to the air as aerosols during fabrication, assembling and testing of components or in accidental or fugitive releases. As a result, workers could be exposed to these compounds by inhalation. A joint research project between SNL and ITRI (Inhalation Toxicology Research Institute) was initiated last fall to investigate the solubility of metal tritides, retention and translocation of inhaled particles and internal dosimetry of metal tritides. The current understanding of metal tritides and their radiation dosimetry for internal exposure are very limited. There is no provision in the ICRP-30 for tritium dosimetry in metal tritide form. However, a few papers in the literature suggested that the solubility of metal tritide could be low. The current radiation protection guidelines for metal tritide particles are based on the assumption that the biological behavior is similar to tritiated water which behaves like body fluid with a relative short biological half life (10 days). If the solubility of metal tritide is low, the biological half life of metal tritide particles and the dosimetry of inhalation exposure to these particles could be quite different from tritiated water. This would have major implications in current radiation protection guidelines for metal tritides Including annual limits of intakes and derived air concentrations. The preliminary results of metal tritide dissolution study at ITRI indicate that the solubility of titanium tritide is low. The outlines of the project, the preliminary results and future work will be discussed in presentation.

  13. Results from 2010 Caliban Criticality Dosimetry Intercomparison

    SciTech Connect

    Veinot, K. G.

    2011-10-12

    The external dosimetry program participated in a criticality dosimetry intercomparison conducted at the Caliban facility in Valduc, France in 2010. Representatives from the dosimetry and instrumentation groups were present during testing which included irradiations of whole-body beta/gamma (HBGT) and neutron thermoluminescent dosimeters (TLDs), a fixed nuclear accident dosimeter (FNAD), electronic alarming dosimeters, and a humanoid phantom filled with reference man concentrations of sodium. This report reviews the testing procedures, preparations, irradiations, and presents results of the tests.

  14. Measuring hydrogen peroxide due to water radiolysis using a modified horseradish peroxidase based biosensor as an alternative dosimetry method.

    PubMed

    Tavakoli, Hassan; Baghbanan, Amin Azam

    2015-08-01

    H2O2 generated during water radiolysis was measured electrochemically as an alternative dosimetry method. A biosensor was fabricated by immobilising modified horseradish peroxidase (HRP) on a glassy carbon electrode (GCE) followed by evaluation of its analytical parameters. Anthraquinone 2-carboxylic acid was used to modify HRP. To assess sensor performance, phosphate buffer solutions were irradiated with 0.510 Gy of gamma ray emitted from (60)Co. The results showed that this sensor can detect low quantities of hydrogen peroxide in water radiolysis. Sensitivity, detection limit and linear range of the biosensor were 260 nA/Gy, 0.392 Gy and 0.5-5 Gy, respectively. Long term stability studies showed that sensor responses were stable for at least a month. The cathodic peak current, as biosensor response, subsequently decreased to 20% of its initial value. PMID:25880374

  15. Fifth personnel dosimetry intercomparison study

    SciTech Connect

    Sims, C.S.

    1980-02-01

    The fifth Personnel Dosimetry Intercomparison Study (PDIS) was conducted at the Oak Ridge National Laboratory's (ORNL) Dosimetry Applications Research (DOSAR) facility on March 20-22, 1979. This study is the latest PDIS in the continuing series started at the DOSAR facility in 1974. The PDIS is a three day study, typically in March, where personnel dosimeters are mailed to the DOSAR facility, exposed to a range of low-level neutron radiation doses (1 to 15 mSv or equivalently, 100 to 1500 mrem) and neutron-to-gamma ratios (1:1-10:1) using the Health Physics Research Reactor (HPRR) as the radiation source, and returned to the participants for evaluation. This report is a summary and analysis of the results reported by the various participants. The participants are able to intercompare their results with those of others who made dose measurements under identical experimental conditions.

  16. Neutron personnel dosimetry intecomparison studies

    SciTech Connect

    Sims, C.S.

    1991-01-01

    The Dosimetry Applications Research (DOSAR) Group at the Oak Ridge National Laboratory (ORNL) has conducted sixteen Neutron Personnel Dosimetry Intercomparison Studies (PDIS) since 1974. During these studies dosimeters are mailed to DOSAR, exposed to low-level (typically in the 0.3 -- 5.0 mSv range) neutron dose equivalents in a variety of mixed neutron-gamma radiation fields, and then returned to the participants for evaluation. The Health Physics Research Reactor (HPRR) was used as the primary radiation source in PDIS 1--12 and radioisotopic neutron sources at DOSAR's Radiation Calibration Laboratory (RADCAL) were mainly used, along with sources and accelerators at cooperating institutions, in PDIS 13--16. Conclusions based on 13,560 measurements made by 146 different participating organizations (102 - US) are presented.

  17. Interspecies dosimetry of reactive gases

    SciTech Connect

    Miller, F.J.; Overton, J.H.; Gerrity, T.R.; Graham, R.C.

    1987-03-01

    The development of dosimetry models that can provide a description of the uptake and distribution of inhaled compounds throughout the body and the availability of animal toxicological data are integral components for a full evaluation of potential risks associated with human exposure. Interspecies dosimetric comparisons must be approached using a model conceptualization that incorporates the major factors affecting the uptake of the gas, such as respiratory tract morphology, route of breathing, depth and rate of breathing, physicochemical properties of the gas, etc. Modeling efforts thus far have primarily focused on ozone. A comparison of theoretical predictions of delivered dose of ozone to the lower respiratory tract of man shows good agreement with dose estimates derived from experimental measurements. Applications to ozone toxicological data in animals and man have been examined that incorporate the use of dosimetry models in studying quantitative dose-response relationships.

  18. Retrospective dosimetry with the MAX/EGS4 exposure model for the radiological accident in Nesvizh-Belarus

    NASA Astrophysics Data System (ADS)

    Santos, A. M.; Kramer, R.; Brayner, C. A.; Khoury, H. J.; Vieira, J. W.

    2007-09-01

    On October 26, 1991 a fatal radiological accident occurred in a 60Co irradiation facility in the town of Nesvizh in Belarus. Following a jam in the product transport system, the operator entered the facility to clear the fault. On entering the irradiation room the operator bypassed a number of safety features, which prevented him from perceiving that the source rack was in the irradiation position. After the accident average whole body absorbed doses between 8 and 16 Gy have been determined by TLD measurements, by isodose rate distributions, by biological dosimetry and by ESR measurements of clothes and teeth. In an earlier investigation the MAX/EGS4 exposure model had been used to calculate absorbed dose distributions for the radiological accident in Yanango/Peru, which actually represented the simulation of exposure from a point source on the surface of the body. After updating the phantom as well as the Monte Carlo code, the MAX/EGS4 exposure model was used to calculate the absorbed dose distribution for the worker involved in the radiological accident in Nesvizh/Belarus. For this purpose, the arms of the MAX phantom had to be raised above the head, and a rectangular 60Co source was designed to represent the source rack used in the irradiation facility. Average organ absorbed doses, depth-absorbed doses, maximum absorbed dose and average whole body absorbed dose have been calculated and compared with the corresponding data given in the IAEA report of the accident.

  19. Neodymium as a magnesium tetraborate matrix dopant and its applicability in dosimetry and as a temperature sensor

    NASA Astrophysics Data System (ADS)

    Souza, Luiza F.; Antonio, Patrícia L.; Caldas, Linda V. E.; Souza, Divanizia N.

    2015-06-01

    MgB4O7 doped with lanthanides such as Dy3+ and Tm3+ are phosphors with very well established use in routine personal dosimetry. Certain characteristics, for example linearity in a broad dose range, low energy dependence, Zeff=8.5, high sensitivity and a relatively simple thermoluminescent (TL) emission curve make MgB4O7 a good material for thermoluminescent dosimetry. With the aim of analyzing other doping possibilities, this paper presents some preliminary results on the use of Nd3+ as a dopant in the MgB4O7 matrix. Furthermore, we evaluated the effect of using two different lanthanides, Nd and Dy, in the host matrix. In the present work, the phosphors were produced through solid state synthesis and X-ray diffraction confirmed the success of the technique. The TL behavior of MgB4O7:Nd was assessed when irradiated with gamma (60Co) and beta radiation, to determine the effect of the dopant concentration and the dose-response over a broad dose range. We also evaluated the dose-response of MgB4O7:Nd,Dy when irradiated with 60Co. The TL responses of the phosphors were compared with that of MgB4O7:Dy. These preliminary studies show that for the absorbed dose range studied, the sensitivity of MgB4O7:Nd,Dy was 3.8 and 28 times higher than that of MgB4O7:Dy and MgB4O7:Nd. The materials also presented linearity from 5 to 40 Gy. Above this value, the dose response curve exhibited sublinear behavior. These preliminary results will assist in developing a new temperature sensor based on a MgB4O7 dosimeter.

  20. A Comparison of the Biological Effects of 125I Seeds Continuous Low-Dose-Rate Radiation and 60Co High-Dose-Rate Gamma Radiation on Non-Small Cell Lung Cancer Cells

    PubMed Central

    Chen, Zhijin; Mao, Aiwu; Teng, Gaojun; Liu, Fenju

    2015-01-01

    Objectives To compare the biological effects of 125I seeds continuous low-dose-rate (CLDR) radiation and 60Co γ-ray high-dose-rate (HDR) radiation on non-small cell lung cancer (NSCLC) cells. Materials and Methods A549, H1299 and BEAS-2B cells were exposed to 125I seeds CLDR radiation or 60Co γ-ray HDR radiation. The survival fraction was determined using a colony-forming assay. The cell cycle progression and apoptosis were detected by flow cytometry (FCM). The expression of the apoptosis-related proteins caspase-3, cleaved-caspase-3, PARP, cleaved-PARP, BAX and Bcl-2 were detected by western blot assay. Results After irradiation with 125I seeds CLDR radiation, there was a lower survival fraction, more pronounced cell cycle arrest (G1 arrest and G2/M arrest in A549 and H1299 cells, respectively) and a higher apoptotic ratio for A549 and H1299 cells than after 60Co γ-ray HDR radiation. Moreover, western blot assays revealed that 125I seeds CLDR radiation remarkably up-regulated the expression of Bax, cleaved-caspase-3 and cleaved-PARP proteins and down-regulated the expression of Bcl-2 proteins in A549 and H1299 cells compared with 60Co γ-ray HDR radiation. However, there was little change in the apoptotic ratio and expression of apoptosis-related proteins in normal BEAS-2B cells receiving the same treatment. Conclusions 125I seeds CLDR radiation led to remarkable growth inhibition of A549 and H1299 cells compared with 60Co HDR γ-ray radiation; A549 cells were the most sensitive to radiation, followed by H1299 cells. In contrast, normal BEAS-2B cells were relatively radio-resistant. The imbalance of the Bcl-2/Bax ratio and the activation of caspase-3 and PARP proteins might play a key role in the anti-proliferative effects induced by 125I seeds CLDR radiation, although other possibilities have not been excluded and will be investigated in future studies. PMID:26266801

  1. Current personnel dosimetry practices at DOE facilities

    SciTech Connect

    Fix, J.J.

    1981-05-01

    Only three parameters were included in the personnel occupational exposure records by all facilities. These are employee name, social security number, and whole body dose. Approximate percentages of some other parameters included in the record systems are sex (50%), birthdate (90%), occupation (26%), previous employer radiation exposure (74%), etc. Statistical analysis of the data for such parameters as sex versus dose distribution, age versus dose distribution, cumulative lifetime dose, etc. was apparently seldom done. Less than 50% of the facilities reported having formal documentation for either the dosimeter, records system, or reader. Slightly greater than 50% of facilities reported having routine procedures in place. These are considered maximum percentages because some respondents considered computer codes as formal documentation. The repository receives data from DOE facilities regarding the (a) distribution of annual whole body doses, (b) significant internal depositions, and (c) individual doses upon termination. It is expected that numerous differences exist in the dose data submitted by the different facilities. Areas of significant differences would likely include the determination of non-measurable doses, the methods used to determine previous employer radiation dose, the methods of determining cumulative radiation dose, and assessment of internal doses. Undoubtedly, the accuracy of the different dosimetry systems, especially at low doses, is very important to the credibility of data summaries (e.g., man-rem) provided by the repository.

  2. Advances in Inhalation Dosimetry Models and Methods for Occupational Risk Assessment and Exposure Limit Derivation

    PubMed Central

    Kuempel, Eileen D.; Sweeney, Lisa M.; Morris, John B.; Jarabek, Annie M.

    2015-01-01

    The purpose of this article is to provide an overview and practical guide to occupational health professionals concerning the derivation and use of dose estimates in risk assessment for development of occupational exposure limits (OELs) for inhaled substances. Dosimetry is the study and practice of measuring or estimating the internal dose of a substance in individuals or a population. Dosimetry thus provides an essential link to understanding the relationship between an external exposure and a biological response. Use of dosimetry principles and tools can improve the accuracy of risk assessment, and reduce the uncertainty, by providing reliable estimates of the internal dose at the target tissue. This is accomplished through specific measurement data or predictive models, when available, or the use of basic dosimetry principles for broad classes of materials. Accurate dose estimation is essential not only for dose-response assessment, but also for interspecies extrapolation and for risk characterization at given exposures. Inhalation dosimetry is the focus of this paper since it is a major route of exposure in the workplace. Practical examples of dose estimation and OEL derivation are provided for inhaled gases and particulates. PMID:26551218

  3. 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.

  4. Proceedings of the second conference on radiation protection and dosimetry

    SciTech Connect

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

    1988-11-01

    The Second Conference on Radiation Protection and Dosimetry was held during October 31--November 3, 1988, at the Holiday Inn, Crowne Plaza Hotel in Orlando, Florida. This meeting was designed with the objectives of promoting communication among applied, research, regulatory, and standards personnel involved in radiation protection and providing them with sufficient information to evaluate their programs. To facilitate meeting these objectives, a technical program consisting of more than 75 invited and contributed oral presentations encompassing all aspects of radiation protection was prepared. General topics considered in the technical sessions included external dosimetry, internal dosimetry, calibration, standards and regulations, instrumentation, accreditation and test programs, research advances, and applied program experience. In addition, special sessions were held to afford attendees the opportunity to make short presentations of recent work or to discuss topics of general interest. This document provides a summary of the conference technical program and a partial collection of full papers for the oral presentations in order of delivery. Individual papers were processed separately for the data base.

  5. A small-scale anatomical dosimetry model of the liver

    NASA Astrophysics Data System (ADS)

    Stenvall, Anna; Larsson, Erik; Strand, Sven-Erik; Jönsson, Bo-Anders

    2014-07-01

    Radionuclide therapy is a growing and promising approach for treating and prolonging the lives of patients with cancer. For therapies where high activities are administered, the liver can become a dose-limiting organ; often with a complex, non-uniform activity distribution and resulting non-uniform absorbed-dose distribution. This paper therefore presents a small-scale dosimetry model for various source-target combinations within the human liver microarchitecture. Using Monte Carlo simulations, Medical Internal Radiation Dose formalism-compatible specific absorbed fractions were calculated for monoenergetic electrons; photons; alpha particles; and 125I, 90Y, 211At, 99mTc, 111In, 177Lu, 131I and 18F. S values and the ratio of local absorbed dose to the whole-organ average absorbed dose was calculated, enabling a transformation of dosimetry calculations from macro- to microstructure level. For heterogeneous activity distributions, for example uptake in Kupffer cells of radionuclides emitting low-energy electrons (125I) or high-LET alpha particles (211At) the target absorbed dose for the part of the space of Disse, closest to the source, was more than eight- and five-fold the average absorbed dose to the liver, respectively. With the increasing interest in radionuclide therapy of the liver, the presented model is an applicable tool for small-scale liver dosimetry in order to study detailed dose-effect relationships in the liver.

  6. 10 CFR 35.630 - Dosimetry equipment.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 1 2012-01-01 2012-01-01 false Dosimetry equipment. 35.630 Section 35.630 Energy NUCLEAR REGULATORY COMMISSION MEDICAL USE OF BYPRODUCT MATERIAL Photon Emitting Remote Afterloader Units, Teletherapy Units, and Gamma Stereotactic Radiosurgery Units § 35.630 Dosimetry equipment. (a) Except for low dose-rate remote afterloader sources...

  7. Dosimetry in Nuclear Medicine Diagnosis and Therapy

    NASA Astrophysics Data System (ADS)

    Noßke, D.; Mattsson, S.; Johansson, L.

    This document is part of Subvolume A 'Fundamentals and Data in Radiobiology, Radiation Biophysics, Dosimetry and Medical Radiological Protection' of Volume 7 'Medical Radiological Physics' of Landolt-Börnstein - Group VIII 'Advanced Materials and Technologies'. It contains the Section '4.7 Necessity of Patient-Specific Dose Planning in Radionuclide Therapy' of the Chapter '4 Dosimetry in Nuclear Medicine Diagnosis and Therapy'.

  8. Shared dosimetry error in epidemiological dose-response analyses

    DOE PAGESBeta

    Stram, Daniel O.; Preston, Dale L.; Sokolnikov, Mikhail; Napier, Bruce; Kopecky, Kenneth J.; Boice, John; Beck, Harold; Till, John; Bouville, Andre; Zeeb, Hajo

    2015-03-23

    Radiation dose reconstruction systems for large-scale epidemiological studies are sophisticated both in providing estimates of dose and in representing dosimetry uncertainty. For example, a computer program was used by the Hanford Thyroid Disease Study to provide 100 realizations of possible dose to study participants. The variation in realizations reflected the range of possible dose for each cohort member consistent with the data on dose determinates in the cohort. Another example is the Mayak Worker Dosimetry System 2013 which estimates both external and internal exposures and provides multiple realizations of "possible" dose history to workers given dose determinants. This paper takesmore » up the problem of dealing with complex dosimetry systems that provide multiple realizations of dose in an epidemiologic analysis. In this paper we derive expected scores and the information matrix for a model used widely in radiation epidemiology, namely the linear excess relative risk (ERR) model that allows for a linear dose response (risk in relation to radiation) and distinguishes between modifiers of background rates and of the excess risk due to exposure. We show that treating the mean dose for each individual (calculated by averaging over the realizations) as if it was true dose (ignoring both shared and unshared dosimetry errors) gives asymptotically unbiased estimates (i.e. the score has expectation zero) and valid tests of the null hypothesis that the ERR slope β is zero. Although the score is unbiased the information matrix (and hence the standard errors of the estimate of β) is biased for β≠0 when ignoring errors in dose estimates, and we show how to adjust the information matrix to remove this bias, using the multiple realizations of dose. The use of these methods in the context of several studies including, the Mayak Worker Cohort, and the U.S. Atomic Veterans Study, is discussed.« less

  9. Shared dosimetry error in epidemiological dose-response analyses

    SciTech Connect

    Stram, Daniel O.; Preston, Dale L.; Sokolnikov, Mikhail; Napier, Bruce; Kopecky, Kenneth J.; Boice, John; Beck, Harold; Till, John; Bouville, Andre; Zeeb, Hajo

    2015-03-23

    Radiation dose reconstruction systems for large-scale epidemiological studies are sophisticated both in providing estimates of dose and in representing dosimetry uncertainty. For example, a computer program was used by the Hanford Thyroid Disease Study to provide 100 realizations of possible dose to study participants. The variation in realizations reflected the range of possible dose for each cohort member consistent with the data on dose determinates in the cohort. Another example is the Mayak Worker Dosimetry System 2013 which estimates both external and internal exposures and provides multiple realizations of "possible" dose history to workers given dose determinants. This paper takes up the problem of dealing with complex dosimetry systems that provide multiple realizations of dose in an epidemiologic analysis. In this paper we derive expected scores and the information matrix for a model used widely in radiation epidemiology, namely the linear excess relative risk (ERR) model that allows for a linear dose response (risk in relation to radiation) and distinguishes between modifiers of background rates and of the excess risk due to exposure. We show that treating the mean dose for each individual (calculated by averaging over the realizations) as if it was true dose (ignoring both shared and unshared dosimetry errors) gives asymptotically unbiased estimates (i.e. the score has expectation zero) and valid tests of the null hypothesis that the ERR slope β is zero. Although the score is unbiased the information matrix (and hence the standard errors of the estimate of β) is biased for β≠0 when ignoring errors in dose estimates, and we show how to adjust the information matrix to remove this bias, using the multiple realizations of dose. The use of these methods in the context of several studies including, the Mayak Worker Cohort, and the U.S. Atomic Veterans Study, is discussed.

  10. Shared dosimetry error in epidemiological dose-response analyses.

    PubMed

    Stram, Daniel O; Preston, Dale L; Sokolnikov, Mikhail; Napier, Bruce; Kopecky, Kenneth J; Boice, John; Beck, Harold; Till, John; Bouville, Andre

    2015-01-01

    Radiation dose reconstruction systems for large-scale epidemiological studies are sophisticated both in providing estimates of dose and in representing dosimetry uncertainty. For example, a computer program was used by the Hanford Thyroid Disease Study to provide 100 realizations of possible dose to study participants. The variation in realizations reflected the range of possible dose for each cohort member consistent with the data on dose determinates in the cohort. Another example is the Mayak Worker Dosimetry System 2013 which estimates both external and internal exposures and provides multiple realizations of "possible" dose history to workers given dose determinants. This paper takes up the problem of dealing with complex dosimetry systems that provide multiple realizations of dose in an epidemiologic analysis. In this paper we derive expected scores and the information matrix for a model used widely in radiation epidemiology, namely the linear excess relative risk (ERR) model that allows for a linear dose response (risk in relation to radiation) and distinguishes between modifiers of background rates and of the excess risk due to exposure. We show that treating the mean dose for each individual (calculated by averaging over the realizations) as if it was true dose (ignoring both shared and unshared dosimetry errors) gives asymptotically unbiased estimates (i.e. the score has expectation zero) and valid tests of the null hypothesis that the ERR slope β is zero. Although the score is unbiased the information matrix (and hence the standard errors of the estimate of β) is biased for β≠0 when ignoring errors in dose estimates, and we show how to adjust the information matrix to remove this bias, using the multiple realizations of dose. The use of these methods in the context of several studies including, the Mayak Worker Cohort, and the U.S. Atomic Veterans Study, is discussed. PMID:25799311

  11. Shared Dosimetry Error in Epidemiological Dose-Response Analyses

    SciTech Connect

    Stram, Daniel; Preston, D. L.; Sokolnkov, Mikhail; Napier, Bruce A.; Kopecky, Kenneth; Boice, John; Beck, Harold L.; Till, John E.; Bouville, A.

    2015-03-23

    Radiation dose reconstruction systems for large-scale epidemiological studies are sophisticated both in providing estimates of dose and in representing dosimetry uncertainty. For example, a computer program was used by the Hanford Thyroid Disease Study to provide 100 realizations of possible dose to study participants. The variation in realizations reflected the range of possible dose for each cohort member consistent with the data on dose determinates in the cohort. Another example is the Mayak Worker Dosimetry System 2013 which estimates both external and internal exposures and provides multiple realizations of "possible" dose history to workers given dose determinants. This paper takes up the problem of dealing with complex dosimetry systems that provide multiple realizations of dose in an epidemiologic analysis. In this paper we derive expected scores and the information matrix for a model used widely in radiation epidemiology, namely the linear excess relative risk (ERR) model that allows for a linear dose response (risk in relation to radiation) and distinguishes between modifiers of background rates and of the excess risk due to exposure. We show that treating the mean dose for each individual (calculated by averaging over the realizations) as if it was true dose (ignoring both shared and unshared dosimetry errors) gives asymptotically unbiased estimates (i.e. the score has expectation zero) and valid tests of the null hypothesis that the ERR slope β is zero. Although the score is unbiased the information matrix (and hence the standard errors of the estimate of β) is biased for β≠0 when ignoring errors in dose estimates, and we show how to adjust the information matrix to remove this bias, using the multiple realizations of dose. Use of these methods for several studies, including the Mayak Worker Cohort and the U.S. Atomic Veterans Study, is discussed.

  12. Shared Dosimetry Error in Epidemiological Dose-Response Analyses

    PubMed Central

    Stram, Daniel O.; Preston, Dale L.; Sokolnikov, Mikhail; Napier, Bruce; Kopecky, Kenneth J.; Boice, John; Beck, Harold; Till, John; Bouville, Andre

    2015-01-01

    Radiation dose reconstruction systems for large-scale epidemiological studies are sophisticated both in providing estimates of dose and in representing dosimetry uncertainty. For example, a computer program was used by the Hanford Thyroid Disease Study to provide 100 realizations of possible dose to study participants. The variation in realizations reflected the range of possible dose for each cohort member consistent with the data on dose determinates in the cohort. Another example is the Mayak Worker Dosimetry System 2013 which estimates both external and internal exposures and provides multiple realizations of "possible" dose history to workers given dose determinants. This paper takes up the problem of dealing with complex dosimetry systems that provide multiple realizations of dose in an epidemiologic analysis. In this paper we derive expected scores and the information matrix for a model used widely in radiation epidemiology, namely the linear excess relative risk (ERR) model that allows for a linear dose response (risk in relation to radiation) and distinguishes between modifiers of background rates and of the excess risk due to exposure. We show that treating the mean dose for each individual (calculated by averaging over the realizations) as if it was true dose (ignoring both shared and unshared dosimetry errors) gives asymptotically unbiased estimates (i.e. the score has expectation zero) and valid tests of the null hypothesis that the ERR slope β is zero. Although the score is unbiased the information matrix (and hence the standard errors of the estimate of β) is biased for β≠0 when ignoring errors in dose estimates, and we show how to adjust the information matrix to remove this bias, using the multiple realizations of dose. The use of these methods in the context of several studies including, the Mayak Worker Cohort, and the U.S. Atomic Veterans Study, is discussed. PMID:25799311

  13. Biological Dosimetry in Astronauts

    NASA Technical Reports Server (NTRS)

    George, Kerry; Cucinotta, Francis A.

    2007-01-01

    Biodosimetry data provides a direct measurement of space radiation damage, which takes into account individual radiosensitivity in the presence of confounding factors such as microgravity and other stress conditions. In contrast to physical measurements, which are external to body and require multiple devices to detect all radiation types all of which have poor sensitivity to neutrons, biodosimetry is internal and includes the effects of shielding provided by the body itself plus chromosome damage shows excellent sensitivity to protons, heavy ions, and neutrons. Moreover, chromosome damage maybe reflective of cancer risk and biodosimetry values can therefore be used to validate and develop risk assessment models that can be used to characterize excess health risk incurred by crewmembers. Cytogenetic biodosimetry methods have been used extensively for assessing terrestrial radiation exposures, and remain the most sensitive in vivo indicator of dose available to date. The main cellular radiation target is the DNA, and radiation-induced damage in the DNA molecule can be visualized as aberrations in the chromosomes (breaks in the chromosomes or exchanges of DNA material between different chromosomes). Normal chromosomes contain a single condensed and constricted area called a centromere that helps the chromosome number to remain stable when a cell divides.

  14. Dosimetry modeling of inhaled toxic reactive gases

    SciTech Connect

    Overton, J.H.; Miller, F.J.

    1986-07-01

    This report focuses on the physical, chemical, and biological processes and factors involved in the absorption of reactive gases. Emphasis is placed on the importance of these factors in developing dosimetry models, special consideration being given to the role of lung fluids and tissues. Several dosimetry models are discussed and illustrations of predicted results presented to demonstrate the application of the models to the uptake of NO/sub 2/ and O/sub 3/, and to demonstrate the use of models in determining the effects of physical, chemical and biological parameters on dosimetry predictions. Gaps in our knowledge and understanding of the processes of dosimetry are pointed out, and research recommendations are made to increase our understanding of the processes and to enhance the development of dosimetry models.

  15. Ozone dosimetry predictions for humans and rats

    SciTech Connect

    Overton, J.H.; Graham, R.C.; McCurdy, T.R.; Richmond, H.M.

    1990-11-01

    The report summarizes ozone (O3) dosimetry model predictions for rats and humans under several different scenarios based on the most recent empirical data and theoretical considerations in the field of O3 dosimetry. The report was prepared at the request of the Office of Air Quality Planning and Standards (OAQPS) as an input to be considered by scientists participating in a chronic lung injury risk assessment project for O3. As indicated in the report a number of judgments and assumptions had to be made to obtain the dosimetry predictions. In addition to presenting the simulation results, the O3 dosimetry model used to make the predictions is discussed and the choice or method of selecting important physiological parameters explained. This includes anatomical dimensions, choices of rat and human ventilatory parameters, and the method of estimating human and rat upper respiratory tract uptake. Finally, a comparison of simulation results to recent experimental dosimetry results is discussed.

  16. Updating and extending the IRDF-2002 dosimetry library

    SciTech Connect

    Capote, R.; Zolotarev, K.I.; Pronyaev, V.G.; Trkov, A.

    2011-07-01

    The International Reactor Dosimetry File (IRDF)-2002 released in 2004 by the IAEA (see http://www-nds.iaea.org/irdf2002/) contains cross-section data and corresponding uncertainties for 66 dosimetry reactions. New cross-section evaluations have become available recently that re-define some of these dosimetry reactions including: (1) high-fidelity evaluation work undertaken by one of the authors (KIZ); (2) evaluations from the US ENDF/B-VII.0 and candidate evaluations from the US ENDF/B-VII.1 libraries that cover reactions within the International Evaluation of Neutron Cross-Section Standards; (3) European JEFF3.1 library; and (4) Japanese JENDL-4.0 library. Additional high-threshold reactions not included in IRDF-2002 (e.g., {sup 59C}o(n,3n) and {sup 209}Bi(n,3n)) have been also evaluated to characterize higher-energy neutron fields. Overall, 37 new evaluations of dosimetry reactions have been assessed and intercomparisons made with integral measurements in reference neutron fields to determine whether they should be adopted to update and improve IRDF-2002. Benchmark calculations performed for newly evaluated reactions using the ENDF/B-VII.0 {sup 235}U thermal fission and {sup 252}Cf spontaneous fission neutron spectra show that calculated integral cross sections exhibit improved agreement with evaluated experimental data when compared with the equivalent data from the IRDF-2002 library. Data inconsistencies or deficiencies of new evaluations have been identified for {sup 63}Cu(n,2n), {sup 60}Ni(n,p) {sup 60m+g}Co, {sup 55}Mn(n,{gamma}), and {sup 232}Th(n,f) reactions. Compared with IRDF-2002, the upper neutron energy boundary was formally increased from the actual maximum energy of typically 20 MeV up to 60 MeV by using the TENDL-2010 cross sections and covariance matrices. This extension would allow the updated IRDF library to be also used in fusion dosimetry applications. Uncertainties in the cross sections for all new evaluations are given in the form of

  17. 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.

  18. The Future of Medical Dosimetry

    SciTech Connect

    Adams, Robert D.

    2015-07-01

    The world of health care delivery is becoming increasingly complex. The purpose of this manuscript is to analyze current metrics and analytically predict future practices and principles of medical dosimetry. The results indicate five potential areas precipitating change factors: a) evolutionary and revolutionary thinking processes, b) social factors, c) economic factors, d) political factors, and e) technological factors. Outcomes indicate that significant changes will occur in the job structure and content of being a practicing medical dosimetrist. Discussion indicates potential variables that can occur within each process and change factor and how the predicted outcomes can deviate from normative values. Finally, based on predicted outcomes, future opportunities for medical dosimetrists are given.

  19. A probabilistic gastrointestinal tract dosimetry model

    NASA Astrophysics Data System (ADS)

    Huh, Chulhaeng

    In internal dosimetry, the tissues of the gastrointestinal (GI) tract represent one of the most radiosensitive organs of the body with the hematopoietic bone marrow. Endoscopic ultrasound is a unique tool to acquire in-vivo data on GI tract wall thicknesses of sufficient resolution needed in radiation dosimetry studies. Through their different echo texture and intensity, five layers of differing echo patterns for superficial mucosa, deep mucosa, submucosa, muscularis propria and serosa exist within the walls of organs composing the alimentary tract. Thicknesses for stomach mucosa ranged from 620 +/- 150 mum to 1320 +/- 80 mum (total stomach wall thicknesses from 2.56 +/- 0.12 to 4.12 +/- 0.11 mm). Measurements made for the rectal images revealed rectal mucosal thicknesses from 150 +/- 90 mum to 670 +/- 110 mum (total rectal wall thicknesses from 2.01 +/- 0.06 to 3.35 +/- 0.46 mm). The mucosa thus accounted for 28 +/- 3% and 16 +/- 6% of the total thickness of the stomach and rectal wall, respectively. Radiation transport simulations were then performed using the Monte Carlo N-particle transport code (MCNP) 4C transport code to calculate S values (Gy/Bq-s) for penetrating and nonpenetrating radiations such as photons, beta particles, conversion electrons and auger electrons of selected nuclides, I123, I131, Tc 99m and Y90 under two source conditions: content and mucosa sources, respectively. The results of this study demonstrate generally good agreement with published data for the stomach mucosa wall. The rectal mucosa data are consistently higher than published data compared with the large intestine due to different radiosensitive cell thicknesses (350 mum vs. a range spanning from 149 mum to 729 mum) and different geometry when a rectal content source is considered. Generally, the ICRP models have been designed to predict the amount of radiation dose in the human body from a "typical" or "reference" individual in a given population. The study has been performed to

  20. A survey of physical dosimetry to date and in the near future: Part 1. Review of standards and regulatory issues.

    PubMed

    Cassata, James R

    2002-02-01

    This article summarizes the status of the relevant standards and current regulatory issues for use of physical dosimetry devices for the occupational worker in the United States. Included is a summary of relevant standards from the International Organization for Standardization (ISO), the International Electrotechnical Commission (IEC), the American National Standards Institute (ANSI), the United States Nuclear Regulatory Commission NUREG-Series, the National Voluntary Laboratory Accreditation Program (NVLAP), the Department of Energy Laboratory Accreditation Program (DOELAP), and the U.S. Military Specifications and Standards (MIL-STD). Proposed changes to ANSI N13.11-1993, "American National Standard for Dosimetry-Personnel Dosimetry Performance Criteria for Testing," are listed. The strategic changes that the United States Nuclear Regulatory Commission (NRC) is making in rulemaking activities related to dosimetry and standards are given. The status of Measurement Program Description (MPD) C.18, "Implementation of Electronic Dosimetry for Primary Dosimetry," from the Council on Ionizing Radiation Measurements and Standards (CIRMS) is given. PMID:11873507

  1. Fourth conference on radiation protection and dosimetry: Proceedings, program, and abstracts

    SciTech Connect

    Casson, W.H.; Thein, C.M.; Bogard, J.S.

    1994-10-01

    This Conference is the fourth in a series of conferences organized by staff members of Oak Ridge National Laboratory in an effort to improve communication in the field of radiation protection and dosimetry. Scientists, regulators, managers, professionals, technologists, and vendors from the United States and countries around the world have taken advantage of this opportunity to meet with their contemporaries and peers in order to exchange information and ideas. The program includes over 100 papers in 9 sessions, plus an additional session for works in progress. Papers are presented in external dosimetry, internal dosimetry, radiation protection programs and assessments, developments in instrumentation and materials, environmental and medical applications, and on topics related to standards, accreditation, and calibration. Individual papers are indexed separately on EDB.

  2. Health physics research reactor reference dosimetry

    SciTech Connect

    Sims, C.S.; Ragan, G.E.

    1987-06-01

    Reference neutron dosimetry is developed for the Health Physics Research Reactor (HPRR) in the new operational configuration directly above its storage pit. This operational change was physically made early in CY 1985. The new reference dosimetry considered in this document is referred to as the 1986 HPRR reference dosimetry and it replaces any and all HPRR reference documents or papers issued prior to 1986. Reference dosimetry is developed for the unshielded HPRR as well as for the reactor with each of five different shield types and configurations. The reference dosimetry is presented in terms of three different dose and six different dose equivalent reporting conventions. These reporting conventions cover most of those in current use by dosimetrists worldwide. In addition to the reference neutron dosimetry, this document contains other useful dosimetry-related data for the HPRR in its new configuration. These data include dose-distance measurements and calculations, gamma dose measurements, neutron-to-gamma ratios, ''9-to-3 inch'' ratios, threshold detector unit measurements, 56-group neutron energy spectra, sulfur fluence measurements, and details concerning HPRR shields. 26 refs., 11 figs., 31 tabs.

  3. Biological dosimetry in Russian and Italian astronauts

    NASA Astrophysics Data System (ADS)

    Greco, O.; Durante, M.; Gialanella, G.; Grossi, G.; Pugliese, M.; Scampoli, P.; Snigiryova, G.; Obe, G.

    Large uncertainties are associated with estimates of equivalent dose and cancer risk for crews of longterm space missions. Biological dosimetry in astronauts is emerging as a useful technique to compare predictions based on quality factors and risk coefficients with actual measurements of biological damage in-flight. In the present study, chromosomal aberrations were analyzed in one Italian and eight Russian cosmonauts following missions of different duration on the MIR and the international space station (ISS). We used the technique of fluorescence in situ hybridization (FISH) to visualize translocations in chromosomes 1 and 2. In some cases, an increase in chromosome damage was observed after flight, but no correlation could be found between chromosome damage and flight history, in terms of number of flights at the time of sampling, duration in space and extra-vehicular activity. Blood samples from one of the cosmonauts were exposed in vitro to 6 MeV X-rays both before and after the flight. An enhancement in radiosensitivity induced by the spaceflight was observed.

  4. Path forward for dosimetry cross sections

    SciTech Connect

    Griffin, P.J.; Peters, C.D.

    2011-07-01

    In the 1980's the dosimetry community embraced the need for a high fidelity quantification of uncertainty in nuclear data used for dosimetry applications. This led to the adoption of energy-dependent covariance matrices as the accepted manner of quantifying the uncertainty data. The trend for the dosimetry community to require high fidelity treatment of uncertainty estimates has continued to the current time where requirements on nuclear data are codified in standards such as ASTM E 1018. This paper surveys the current state of the dosimetry cross sections and investigates the quality of the current dosimetry cross section evaluations by examining calculated-to-experimental ratios in neutron benchmark fields. In recent years more nuclear-related technical areas are placing an emphasis on uncertainty quantification. With the availability of model-based cross sections and covariance matrices produced by nuclear data codes, some nuclear-related communities are considering the role these covariance matrices should play. While funding within the dosimetry community for cross section evaluations has been very meager, other areas, such as the solar-related astrophysics community and the US Nuclear Criticality Safety Program, have been supporting research in the area of neutron cross sections. The Cross Section Evaluation Working Group (CSEWG) is responsible for the creation and maintenance of the ENDF/B library which has been the mainstay for the reactor dosimetry community. Given the new trends in cross section evaluations, this paper explores the path forward for the US nuclear reactor dosimetry community and its use of the ENDF/B cross-sections. The major concern is maintenance of the sufficiency and accuracy of the uncertainty estimate when used for dosimetry applications. The two major areas of deficiency in the proposed ENDF/B approach are: 1) the use of unrelated covariance matrices in ENDF/B evaluations and 2) the lack of 'due consideration' of experimental data

  5. Measurement of the 58Ni(n,t)56Co, 59Co(n,p)59Fe, and 63Cu(n,{alpha})60Co Reaction Cross Sections from 14 to 20 MeV

    SciTech Connect

    Semkova, V.; Plompen, A.J.M.; Smith, D.L.

    2005-05-24

    Neutron activation cross sections for the 63Cu(n,{alpha})60Co, 59Co(n,p)59Fe, and 58Ni(n,t)56Co reactions were measured in the energy range from 13 to 21 MeV. The irradiations were carried out at the 7-MV Van de Graaff accelerator at IRMM, Geel. Quasi-monoenergetic neutrons were produced via the 3H(d,n)4He reaction at 1-, 2-, 3-, and 4-MeV incident deuteron energy. All reaction cross sections measured in the present work are referenced to the 27Al(n,{alpha})24Na standard reaction cross section. Neutron flux spectra were determined by an activation spectral index method in combination with TOF spectrum measurements. Standard {gamma}-ray spectrometry was employed for the measurement of radioactivity. The measured results are compared with work by other authors, TALYS-0.57 and EMPIRE-II model calculations, and current evaluated data files. The new results contribute substantially to the experimental database of the measured reactions. Recommendations are provided for the best evaluations for the 59Co(n,p)59Fe, and 63Cu(n,{alpha})60Co reactions. For the 58Ni(n,t)56Co reaction no current evaluation is in good agreement with all available data. For this reaction further measurements would help to guide new modeling efforts.

  6. 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

  7. Cross sections required for FMIT dosimetry

    SciTech Connect

    Gold, R.; McElroy, W.N.; Lippincott, E.P.; Mann, F.M.; Oberg, D.L.; Roberts, J.H.; Ruddy, F.H.

    1980-05-02

    The Fusion Materials Irradiation Test (FMIT) facility, currently under construction, is designed to produce a high flux of high energy neutrons for irradiation effects experiments on fusion reactor materials. Characterization of the flux-fluence-spectrum in this rapidly varying neutron field requires adaptation and extension of currently available dosimetry techniques. This characterization will be carried out by a combination of active, passive, and calculational dosimetry. The goal is to provide the experimenter with accurate neutron flux-fluence-spectra at all positions in the test cell. Plans have been completed for a number of experimental dosimetry stations and provision for these facilities has been incorporated into the FMIT design. Overall needs of the FMIT irradiation damage program delineate goal accuracies for dosimetry that, in turn, create new requirements for high energy neutron cross section data. Recommendations based on these needs have been derived for required cross section data and accuracies.

  8. INTERSPECIES DOSIMETRY MODELS FOR PULMONARY PHARMACOLOGY

    EPA Science Inventory

    Interspecies Dosimetry Models for Pulmonary Pharmacology

    Ted B. Martonen, Jeffry D. Schroeter, and John S. Fleming

    Experimental Toxicology Division, National Health and Environmental Effects Research Laboratory, U.S. Environmental Protection Agency, Research Triangl...

  9. 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.

  10. Aufgaben und Genauigkeit der klinischen Dosimetrie

    NASA Astrophysics Data System (ADS)

    Krieger, Hanno

    In diesem Kapitel werden die Aufgaben der klinischen Dosimetrie für die verschiedenen radiologischen Disziplinen zusammengestellt. Die wichtigste Aufgabe ist die Messung der im bestrahlten Medium entstandenen Energiedosis für die verschiedenen Strahlungsquellen. Die am weitesten verbreitete dazu verwendete Methode ist die Dosismessung mit gasgefüllten Ionisationskammern. Im zweiten Teil des Kapitels werden die Genauigkeitsanforderungen der klinischen Dosimetrie diskutiert.

  11. 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.

  12. Development of A phantom for ophthalmic beta source applicator quality control using TL dosimetry

    NASA Astrophysics Data System (ADS)

    Barbosa, N. A.; da Rosa, L. A. R.; Braz, D.

    2015-11-01

    Concave eye applicators with 90Sr/90Y and 106Ru/106Rh beta ray sources are usually used in brachytherapy for the treatment of superficial intraocular tumors as uveal melanoma with thickness up to 5 mm. The calculation of the dose delivered to the eye is carried out based on the data present in the beta source calibration certificate. Therefore, it would be interesting to have a system that could evaluate that dose. In this work, an eye phantom to be used with 106Ru/106Rh betatherapy applicators was developed in solid water. This phantom can hold nine micro-cube thermoluminescent (TL) dosimeters, TLD-100. The characteristics of the TL response of the dosimeters, namely reproducibility and individual sensitivity, were determined for a 60Co source. Using Monte Carlo code MCNPX, the dose to a water eye was determined at different depths. Exposing the eye phantom with TL dosimeters to the 106Ru/106Rh applicator, it is possible to assess calibration factors using the dose values obtained by Monte Carlo simulation to each depth. Using mean calibration factors, dose values obtained by TL dosimetry were compared to the data present in the applicators certificate. Mean differences for both applicators were lower than ±10%, maximum value 17% and minimum value 0.08%. Considering that the certificate values present an uncertainty of ±20%, the calibration procedure and the developed phantom are validated and can be applied.

  13. Application of a new dosimetry formalism to volumetric modulated arc therapy (VMAT)

    NASA Astrophysics Data System (ADS)

    Rosser, Karen E.; Bedford, James L.

    2009-12-01

    Volumetric modulated arc therapy (VMAT) offers a challenge to classical dosimetry protocols as the beams are dynamic in orientation and aperture shape and may include small apertures. The aim of this paper is to apply a formalism to VMAT beams that has recently been published by the International Atomic Energy Agency (IAEA) working party to improve the dosimetry for small and non-standard fields. We investigated three possible fields and assessed their suitability as plan class specific reference (pcsr) fields. The factors in the new dosimetry formalism were investigated: the conversion of dose to water from the conventional reference field to the pcsr and then from the pcsr to a treatment plan, using a PTW semiflex chamber, two Farmer chambers and an electron diode. Finally, the dose was compared for Alanine, the new formalism and calculated using Pinnacle3 (Philips Radiation Oncology Systems) for two typical clinical VMAT beams. Correction factors between the reference field and the pcsr determined with Alanine range from 0.1% to 2.3% for the three pcsr fields. Dose to water measured using the calibrated ionization chambers is less than 2% different to the dose calculated by Pinnacle3. VMAT planning and delivery procedures have been successfully implemented and a new dosimetry protocol has been investigated for this new technique. Calibration factors for pcsr fields are found to be up to 2.3% different when using the new formalism, compared to using a standard dosimetry protocol. Using the calibration factors determined in the pcsr fields, the ionization chambers and electron diode agree to within 1% with Alanine dosimetry for two clinical VMAT plans. Good agreements between calculations and measurements are found for these two plans when the new formalism is used.

  14. In aqua vivo EPID dosimetry

    SciTech Connect

    Wendling, Markus; McDermott, Leah N.; Mans, Anton; Olaciregui-Ruiz, Igor; Pecharroman-Gallego, Raul; Sonke, Jan-Jakob; Stroom, Joep; Herk, Marcel J.; Mijnheer, Ben van

    2012-01-15

    Purpose: At the Netherlands Cancer Institute-Antoni van Leeuwenhoek Hospital in vivo dosimetry using an electronic portal imaging device (EPID) has been implemented for almost all high-energy photon treatments of cancer with curative intent. Lung cancer treatments were initially excluded, because the original back-projection dose-reconstruction algorithm uses water-based scatter-correction kernels and therefore does not account for tissue inhomogeneities accurately. The aim of this study was to test a new method, in aqua vivo EPID dosimetry, for fast dose verification of lung cancer irradiations during actual patient treatment. Methods: The key feature of our method is the dose reconstruction in the patient from EPID images, obtained during the actual treatment, whereby the images have been converted to a situation as if the patient consisted entirely of water; hence, the method is termed in aqua vivo. This is done by multiplying the measured in vivo EPID image with the ratio of two digitally reconstructed transmission images for the unit-density and inhomogeneous tissue situation. For dose verification, a comparison is made with the calculated dose distribution with the inhomogeneity correction switched off. IMRT treatment verification is performed for each beam in 2D using a 2D {gamma} evaluation, while for the verification of volumetric-modulated arc therapy (VMAT) treatments in 3D a 3D {gamma} evaluation is applied using the same parameters (3%, 3 mm). The method was tested using two inhomogeneous phantoms simulating a tumor in lung and measuring its sensitivity for patient positioning errors. Subsequently five IMRT and five VMAT clinical lung cancer treatments were investigated, using both the conventional back-projection algorithm and the in aqua vivo method. The verification results of the in aqua vivo method were statistically analyzed for 751 lung cancer patients treated with IMRT and 50 lung cancer patients treated with VMAT. Results: The improvements by

  15. Influence of phantom materials on the energy dependence of LiF:Mg,Ti thermoluminescent dosimeters exposed to 20-300 kV narrow x-ray spectra, 137Cs and 60Co photons

    NASA Astrophysics Data System (ADS)

    Massillon-JL, G.; Cabrera-Santiago, A.; Minniti, R.; O'Brien, M.; Soares, C. G.

    2014-08-01

    LiF:Mg,Ti, are widely used to estimate absorbed-dose received by patients during diagnostic or medical treatment. Conveniently, measurements are usually made in plastic phantoms. However, experimental conditions vary from one group to another and consequently, a lack of consensus data exists for the energy dependence of thermoluminescent (TL) response. This work investigated the energy dependence of TLD-100 TL-response and the effect of irradiating the dosimeters in different phantom materials for a broad range of energy photons in an attempt to understand the parameters that affect the discrepancies reported by various research groups. TLD-100s were exposed to 20-300 kV narrow x-ray spectra, 137Cs and 60Co photons. Measurements were performed in air, PMMA, wt1, polystyrene and TLDS as surrounding material. Total air-kerma values delivered were between 50 and 150 mGy for x-rays and 50 mGy for 137Cs and 60Co beams; each dosimeter was irradiated individually. Relative response, R, defined as the TL-response per air-kerma and relative efficiency, RE, described as the TL-response per absorbed-dose (obtained through Monte Carlo (MC) and analytically) were used to describe the TL-response. Both R and RE are normalized to the responses in a 60Co beam. The results indicate that the use of different phantom materials affects the TL-response and this response varies with energy and material type. MC simulations reproduced qualitatively the experimental data: a) R increases, reaches a maximum at ~25 keV and decreases; b) RE decreases, down to a minimum at ~60 keV, increases to a maximum at ~150 keV and after decreases. Independent of the phantom materials, RE strongly depends on how the absorbed dose is evaluated and the discrepancies between RE evaluated analytically and by MC simulation are around 4% and 18%, dependent on the photon energy. The comparison between our results and that reported in the literature suggests that the discrepancy observed between

  16. Comment on ‘Monte Carlo calculated microdosimetric spread for cell nucleus-sized targets exposed to brachytherapy 125I and 192Ir sources and 60Co cell irradiation’

    NASA Astrophysics Data System (ADS)

    Lindborg, Lennart; Lillhök, Jan; Grindborg, Jan-Erik

    2015-11-01

    The relative standard deviation, σr,D, of calculated multi-event distributions of specific energy for 60Co ϒ rays was reported by the authors F Villegas, N Tilly and A Ahnesjö (Phys. Med. Biol. 58 6149-62). The calculations were made with an upgraded version of the Monte Carlo code PENELOPE. When the results were compared to results derived from experiments with the variance method and simulated tissue equivalent volumes in the micrometre range a difference of about 50% was found. Villegas et al suggest wall-effects as the likely explanation for the difference. In this comment we review some publications on wall-effects and conclude that wall-effects are not a likely explanation.

  17. Effects of /sup 60/Co radiation on synthesis of prostaglandins F/sub 2//sub. cap alpha. /, E, and thromboxane B/sub 2/ in lung airways of guinea pigs

    SciTech Connect

    Steel, L.K.; Sweedler, I.K.; Catravas, G.N.

    1983-04-01

    At 1 hr to 14 days after total-body exposure of guinea pigs to 3.0 Gy /sup 60/Co, changes were detected in prostaglandin concentrations in bronchial airway tissues. At 3 hr postexposure, tissue levels of PGE were significantly elevated, while at 48 hr transiently elevated levels of PGF/sub 2//sub ..cap alpha../ were observed. By 72 hr, levels returned to control values. Airway synthesis of thromboxane B/sub 2/ in irradiated animals did not differ from that in controls. Also assessed were the capacities of bronchial airway preparations to respond to H-1 receptor stimulation by the exogenous addition of histamine or transmembrane divalent cation transport stimulation with ionophore. Tissues from irradiated animals demonstrated alterations in the amount and type of prostaglandins generated, varying with time postirradiation.

  18. Tenth value layers for 60Co gamma rays and for 4, 6, 10, 15, and 18 MV x rays in concrete for beams of cone angles between 0 degrees and 14 degrees calculated by Monte Carlo simulation.

    PubMed

    Jaradat, Adnan K; Biggs, Peter J

    2007-05-01

    The calculation of shielding barrier thicknesses for radiation therapy facilities according to the NCRP formalism is based on the use of broad beams (that is, the maximum possible field sizes). However, in practice, treatment fields used in radiation therapy are, on average, less than half the maximum size. Indeed, many contemporary treatment techniques call for reduced field sizes to reduce co-morbidity and the risk of second cancers. Therefore, published tenth value layers (TVLs) for shielding materials do not apply to these very small fields. There is, hence, a need to determine the TVLs for various beam modalities as a function of field size. The attenuation of (60)Co gamma rays and photons of 4, 6, 10, 15, and 18 MV bremsstrahlung x ray beams by concrete has been studied using the Monte Carlo technique (MCNP version 4C2) for beams of half-opening angles of 0 degrees , 3 degrees , 6 degrees , 9 degrees , 12 degrees , and 14 degrees . The distance between the x-ray source and the distal surface of the shielding wall was fixed at 600 cm, a distance that is typical for modern radiation therapy rooms. The maximum concrete thickness varied between 76.5 cm and 151.5 cm for (60)Co and 18 MV x rays, respectively. Detectors were placed at 630 cm, 700 cm, and 800 cm from the source. TVLs have been determined down to the third TVL. Energy spectra for 4, 6, 10, 15, and 18 MV x rays for 10 x 10 cm(2) and 40 x 40 cm(2) field sizes were used to generate depth dose curves in water that were compared with experimentally measured values. PMID:17429304

  19. LiF:Mg,Ti TLD response as a function of photon energy for moderately filtered x-ray spectra in the range of 20-250 kVp relative to {sup 60}Co

    SciTech Connect

    Nunn, A. A.; Davis, S. D.; Micka, J. A.; DeWerd, L. A.

    2008-05-15

    The response of LiF:Mg,Ti thermoluminescent dosimeters (TLDs) as a function of photon energy was determined using irradiations with moderately filtered x-ray beams in the energy range of 20-250 kVp relative to the response to irradiations with {sup 60}Co photons. To determine if the relative light output from LiF:Mg,Ti TLDs per unit air kerma as a function of photon energy can be predicted using calculations such as Monte Carlo (MC) simulations, measurements from the x-ray beam irradiations were compared with MC calculated results, similar to the methodology used by Davis et al. [Radiat. Prot. Dosim. 106, 33-43 (2003)]. TLDs were irradiated in photon beams with well-known air kerma rates using the National Institute of Standards and Technology traceable M-series x-ray beams in the range of 20-250 kVp. For each x-ray beam, several sets of TLDs were irradiated for times corresponding to different air kerma levels to take into account any dose nonlinearity. TLD light output was then compared to that from several sets of TLDs irradiated at similar corresponding air kerma levels using a {sup 60}Co irradiator. The MC code MCNP5 was used to account for photon scatter and attenuation in the holder and TLDs and was used to calculate the predicted relative TLD light output per unit air kerma for irradiations with each of the experimentally used photon beams. The measured relative TLD response as a function of photon energy differed by up to 13% from the MC calculations. We conclude that MC calculations do not accurately predict the relative response of TLDs as a function of photon energy, consistent with the conclusions of Davis et al. [Radiat. Prot. Dosim. 106, 33-43 (2003)]. This is likely due to complications in the solid state physics of the thermoluminescence process that are not incorporated into the simulation.

  20. Technical Basis Document for PFP Area Monitoring Dosimetry Program

    SciTech Connect

    COOPER, J.R.

    2000-04-17

    This document describes the phantom dosimetry used for the PFP Area Monitoring program and establishes the basis for the Plutonium Finishing Plant's (PFP) area monitoring dosimetry program in accordance with the following requirements: Title 10, Code of Federal Regulations (CFR), part 835, ''Occupational Radiation Protection'' Part 835.403; Hanford Site Radiological Control Manual (HSRCM-1), Part 514; HNF-PRO-382, Area Dosimetry Program; and PNL-MA-842, Hanford External Dosimetry Technical Basis Manual.

  1. 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.

  2. Body growth considerations in age-specific dosimetry. Final report

    SciTech Connect

    Eckerman, K.F.

    1993-09-30

    This report describes the manner in which the age-specific dosimetric calculations of the International Commission on Radiological Protection (ICRP) addressed changes in organ size that occur with age. The approach involves an interpolation of dosimetric information derived for six reference individuals using the inverse of the total body mass as the interpolation variable. An alternative formulation is investigated that employs a functional representation of the organ mass as a function of age in conjunction with an explicit formulation of the dosimetric factors in terms of organ mass. Using an exponential-logistic growth function as suggested by Walker, this report demonstrates, through application to the dosimetry of radioiodines in the thyroid, that the alternative formulation can be formulated and implemented. Although either approach provides a workable basis for age-specific dosimetry, it is clear that the functional representation of organ growth has some attractive features. However, without question, the major difficulty is the quality and quantity of data available to address the age- and gender-specific parameters in the dosimetric formulations.

  3. Postured voxel-based human models for electromagnetic dosimetry

    NASA Astrophysics Data System (ADS)

    Nagaoka, Tomoaki; Watanabe, Soichi

    2008-12-01

    High-resolution anatomically realistic whole-body voxel models have recently been developed for electromagnetic dosimetry. However, the posture of most models is similar to the standing one, which strongly limits electromagnetic dosimetry when simulating a realistic exposure scenario. In this paper, we present the development of postured models based on anatomically realistic voxel models with standing posture. Voxel models of the Japanese adult male and female were used as the original upright standing models. The Japanese models were composed of 2 mm cubic voxels, each of which was segmented into 51 different tissue types. We developed several different types of posture models using a novel posture transformation method. These posture models were smoothly transformed, while the continuity of the internal tissues and organs was maintained. In this paper, we also present our calculations of the whole-body averaged specific absorption rates (SARs) of sitting male and female models exposed to electromagnetic plane waves at very high (VHF) and ultra high frequency (UHF) bands.

  4. Dosimetry in Mammography: Average Glandular Dose Based on Homogeneous Phantom

    NASA Astrophysics Data System (ADS)

    Benevides, Luis A.; Hintenlang, David E.

    2011-05-01

    The objective of this study was to demonstrate that a clinical dosimetry protocol that utilizes a dosimetric breast phantom series based on population anthropometric measurements can reliably predict the average glandular dose (AGD) imparted to the patient during a routine screening mammogram. AGD was calculated using entrance skin exposure and dose conversion factors based on fibroglandular content, compressed breast thickness, mammography unit parameters and modifying parameters for homogeneous phantom (phantom factor), compressed breast lateral dimensions (volume factor) and anatomical features (anatomical factor). The patient fibroglandular content was evaluated using a calibrated modified breast tissue equivalent homogeneous phantom series (BRTES-MOD) designed from anthropomorphic measurements of a screening mammography population and whose elemental composition was referenced to International Commission on Radiation Units and Measurements Report 44 and 46 tissues. The patient fibroglandular content, compressed breast thickness along with unit parameters and spectrum half-value layer were used to derive the currently used dose conversion factor (DgN). The study showed that the use of a homogeneous phantom, patient compressed breast lateral dimensions and patient anatomical features can affect AGD by as much as 12%, 3% and 1%, respectively. The protocol was found to be superior to existing methodologies. The clinical dosimetry protocol developed in this study can reliably predict the AGD imparted to an individual patient during a routine screening mammogram.

  5. Dosimetry in Mammography: Average Glandular Dose Based on Homogeneous Phantom

    SciTech Connect

    Benevides, Luis A.; Hintenlang, David E.

    2011-05-05

    The objective of this study was to demonstrate that a clinical dosimetry protocol that utilizes a dosimetric breast phantom series based on population anthropometric measurements can reliably predict the average glandular dose (AGD) imparted to the patient during a routine screening mammogram. AGD was calculated using entrance skin exposure and dose conversion factors based on fibroglandular content, compressed breast thickness, mammography unit parameters and modifying parameters for homogeneous phantom (phantom factor), compressed breast lateral dimensions (volume factor) and anatomical features (anatomical factor). The patient fibroglandular content was evaluated using a calibrated modified breast tissue equivalent homogeneous phantom series (BRTES-MOD) designed from anthropomorphic measurements of a screening mammography population and whose elemental composition was referenced to International Commission on Radiation Units and Measurements Report 44 and 46 tissues. The patient fibroglandular content, compressed breast thickness along with unit parameters and spectrum half-value layer were used to derive the currently used dose conversion factor (DgN). The study showed that the use of a homogeneous phantom, patient compressed breast lateral dimensions and patient anatomical features can affect AGD by as much as 12%, 3% and 1%, respectively. The protocol was found to be superior to existing methodologies. The clinical dosimetry protocol developed in this study can reliably predict the AGD imparted to an individual patient during a routine screening mammogram.

  6. 10 CFR 835.1304 - Nuclear accident dosimetry.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 4 2010-01-01 2010-01-01 false Nuclear accident dosimetry. 835.1304 Section 835.1304... Nuclear accident dosimetry. (a) Installations possessing sufficient quantities of fissile material to... nuclear accident is possible, shall provide nuclear accident dosimetry for those individuals. (b)...

  7. 10 CFR 835.1304 - Nuclear accident dosimetry.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 4 2011-01-01 2011-01-01 false Nuclear accident dosimetry. 835.1304 Section 835.1304... Nuclear accident dosimetry. (a) Installations possessing sufficient quantities of fissile material to... nuclear accident is possible, shall provide nuclear accident dosimetry for those individuals. (b)...

  8. Validating the ENDF-B/VII{sup 235}U(n{sub th},f) prompt fission neutron spectrum using updated dosimetry cross sections (IRDFF)

    SciTech Connect

    Capote, R.; Zolotarev, K. I.; Pronyaev, V. G.; Trkov, A.

    2012-07-01

    The International Reactor Dosimetry File IRDF-2002 released in 2004 by the IAEA contains cross-section data and corresponding uncertainties for 66 dosimetry reactions. New cross-section evaluations have become available recently that re-define some of these dosimetry reactions for reactor applications including: 1) high fidelity evaluation work undertaken by one of the authors (KIZ); 2) evaluations from the ENDF/B-VII libraries that cover reactions within the International Evaluation of Neutron Cross-Section Standards; and 3) evaluations from JENDL-3.1 and JENDL-4 libraries. Overall, 37 new evaluations of dosimetry reactions have been assessed to determine whether they should be adopted to update and improve IRDF-2002. A new dosimetry library (International Reactor Dosimetry File for Fission and Fusion - IRDFF) was assembled based on new evaluations combined with selected IRDF-2002 evaluations. A grand-total of 74 dosimetry reactions are included into the IRDFF dosimetry library available at www-nds.iaea.org/IRDFFI. The assembled library was used to validate the {sup 235}U(n{sub th},f) ENDF-B/VII.0 prompt fission neutron spectrum. An excellent average C/E value of 1.002 +/- 0.02 is achieved for reactions with mean neutron energy of the integrated response (E50%) lower than 11 MeV. C/E data for reactions with E50%-response higher than 11 MeV decreases up to 0.8. We conclude that the ENDF-B/VII.0 {sup 235}U(n{sub th},f) prompt fission neutron spectrum from 1-11 MeV is validated within quoted uncertainties by available integral measurements in {sup 235}U(n{sub th},f) neutron field. Further investigations for high-threshold reactions are needed and new measurements of spectrum average cross sections for those reactions in the {sup 235}U(n{sub th},f) neutron field are recommended. (authors)

  9. Incorporating High-Throughput Exposure Predictions with Dosimetry-Adjusted In Vitro Bioactivity to Inform Chemical Toxicity Testing

    EPA Science Inventory

    We previously integrated dosimetry and exposure with high-throughput screening (HTS) to enhance the utility of ToxCast™ HTS data by translating in vitro bioactivity concentrations to oral equivalent doses (OEDs) required to achieve these levels internally. These OEDs were compare...

  10. 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.

  11. 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

  12. 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

  13. VIDA: A Voxel-Based Dosimetry Method for Targeted Radionuclide Therapy Using Geant4

    PubMed Central

    Dewaraja, Yuni K.; Abramson, Richard G.; Stabin, Michael G.

    2015-01-01

    Abstract We have developed the Voxel-Based Internal Dosimetry Application (VIDA) to provide patient-specific dosimetry in targeted radionuclide therapy performing Monte Carlo simulations of radiation transport with the Geant4 toolkit. The code generates voxel-level dose rate maps using anatomical and physiological data taken from individual patients. Voxel level dose rate curves are then fit and integrated to yield a spatial map of radiation absorbed dose. In this article, we present validation studies using established dosimetry results, including self-dose factors (DFs) from the OLINDA/EXM program for uniform activity in unit density spheres and organ self- and cross-organ DFs in the Radiation Dose Assessment Resource (RADAR) reference adult phantom. The comparison with reference data demonstrated agreement within 5% for self-DFs to spheres and reference phantom source organs for four common radionuclides used in targeted therapy (131I, 90Y, 111In, 177Lu). Agreement within 9% was achieved for cross-organ DFs. We also present dose estimates to normal tissues and tumors from studies of two non-Hodgkin Lymphoma patients treated by 131I radioimmunotherapy, with comparison to results generated independently with another dosimetry code. A relative difference of 12% or less was found between methods for mean absorbed tumor doses accounting for tumor regression. PMID:25594357

  14. VIDA: a voxel-based dosimetry method for targeted radionuclide therapy using Geant4.

    PubMed

    Kost, Susan D; Dewaraja, Yuni K; Abramson, Richard G; Stabin, Michael G

    2015-02-01

    We have developed the Voxel-Based Internal Dosimetry Application (VIDA) to provide patient-specific dosimetry in targeted radionuclide therapy performing Monte Carlo simulations of radiation transport with the Geant4 toolkit. The code generates voxel-level dose rate maps using anatomical and physiological data taken from individual patients. Voxel level dose rate curves are then fit and integrated to yield a spatial map of radiation absorbed dose. In this article, we present validation studies using established dosimetry results, including self-dose factors (DFs) from the OLINDA/EXM program for uniform activity in unit density spheres and organ self- and cross-organ DFs in the Radiation Dose Assessment Resource (RADAR) reference adult phantom. The comparison with reference data demonstrated agreement within 5% for self-DFs to spheres and reference phantom source organs for four common radionuclides used in targeted therapy ((131)I, (90)Y, (111)In, (177)Lu). Agreement within 9% was achieved for cross-organ DFs. We also present dose estimates to normal tissues and tumors from studies of two non-Hodgkin Lymphoma patients treated by (131)I radioimmunotherapy, with comparison to results generated independently with another dosimetry code. A relative difference of 12% or less was found between methods for mean absorbed tumor doses accounting for tumor regression. PMID:25594357

  15. HSE performance tests for dosimetry services.

    PubMed

    Birch, R; Simpson, J A; Hedley, R P; Wardle, J

    2000-12-01

    In the United Kingdom a dosimetry service that measures and assesses whole-body or part-body doses arising from external radiation must successfully complete a performance test. Results of the performance tests for routine whole-body, routine extremity/skin and special accident dosimetry, carried out over the past six years by the AEA Technology Calibration Service at Winfrith, and DRaStaC, the AWE Calibration Service at Aldermaston, are presented. The test involves irradiating groups of dosemeters to known doses of gamma radiation and determining the bias and relative standard deviations for each dose group. The results are compared with the pass criteria specified by the UK Health and Safety Executive. For routine whole-body dosimetry, both the film badge and thermoluminescent dosemeter (TLD) perform adequately for irradiations between 0.6 and 30 mSv. For higher doses up to 250 mSv, where the slow emulsion of the film is used, the film badge shows poorer performance with a tendency to overestimate the dose. For routine extremity/skin dosimetry there is a wider spread of relative standard deviation results than is seen for routine whole-body dosimetry. This is to be expected since the results will include dosemeters that are based on 'disposable' TLDs and ones based on lithium fluoride powder in sachets. For special accident dosimetry the dosemeters are tested between 0.26 and 6 Gy. For the highest dose group the film badge invariably underestimates the true dose, whereas the TLD has a tendency to overestimate it. PMID:11140715

  16. A prototype, glassless densitometer traceable to primary optical standards for quantitative radiochromic film dosimetry

    SciTech Connect

    Rosen, B. S. Hammer, C. G.; Kunugi, K. A.; DeWerd, L. A.; Soares, C. G.

    2015-07-15

    Purpose: To evaluate a prototype densitometer traceable to primary optical standards and compare its performance to an EPSON Expression{sup ®} 10000XL flatbed scanner (the Epson) for quantitative radiochromic film (RCF) dosimetry. Methods: A prototype traceable laser densitometry system (LDS) was developed to mitigate common film scanning artifacts, such as positional scan dependence and high noise in low-dose regions, by performing point-based measurements of RCF suspended in free-space using coherent light. The LDS and the Epson optical absorbance scales were calibrated up to 3 AU, using reference materials calibrated at a primary standards laboratory and a scanner calibration factor (SCF). Calibrated optical density (OD) was determined for 96 Gafchromic{sup ®} EBT3 film segments before and after irradiation to one of 16 dose levels between 0 and 10 Gy, exposed to {sup 60}Co in a polymethyl-methacrylate (PMMA) phantom. The sensitivity was determined at each dose level and at two rotationally orthogonal readout orientations to obtain the sensitometric response of each RCF dosimetry system. LDS rotational scanning dependence was measured at nine angles between 0°and 180°, due to the expected interference between coherent light and polarizing EBT3 material. The response curves were fit to the analytic functions predicted by two physical response models: the two-parameter single-hit model and the four-parameter percolation model. Results: The LDS and the Epson absorbance measurements were linear to primary optical standards to within 0.2% and 0.3% up to 2 and 1 AU, respectively. At higher densities, the LDS had an over-response (2.5% at 3 AU) and the Epson an under-response (3.1% and 9.8% at 2 and 3 AU, respectively). The LDS and the Epson SCF over the applicable range were 0.968% ± 0.2% and 1.561% ± 0.3%, respectively. The positional scan dependence was evaluated on each digitizer and shown to be mitigated on the LDS, as compared to the Epson. Maximum EBT3

  17. Practical neutron dosimetry at high energies

    SciTech Connect

    McCaslin, J.B.; Thomas, R.H.

    1980-10-01

    Dosimetry at high energy particle accelerators is discussed with emphasis on physical measurements which define the radiation environment and provide an immutable basis for the derivation of any quantities subsequently required for risk evaluation. Results of inter-laboratory dosimetric comparisons are reviewed and it is concluded that a well-supported systematic program is needed which would make possible detailed evaluations and inter-comparisons of instruments and techniques in well characterized high energy radiation fields. High-energy dosimetry is so coupled with radiation transport that it is clear their study should proceed concurrently.

  18. Applicability of Topaz Composites to Electron Dosimetry

    NASA Astrophysics Data System (ADS)

    Bomfim, K. S.; Souza, D. N.

    2010-11-01

    Thermoluminescent dosimetric topaz properties have been investigated and the results have shown that this mineral presents characteristics of a good dosimeter mainly in doses evaluation in radiotherapy with photons beams in radiotherapy. Typical applications of thermoluminescent dosimeters in radiotherapy are: in vivo dosimetry on patients (either as a routine quality assurance procedure or for dose monitoring in special cases); verification of treatment techniques; dosimetry audits; and comparisons among hospitals. The mean aim of this work was to evaluate the efficiency of topaz-Teflon pellets as thermoluminescent dosimeters in high-energy electron beams used to radiotherapy. Topaz-Teflon pellets were used as TLD.

  19. Recent progresses in tritium radioecology and dosimetry

    SciTech Connect

    Galeriu, D.; Davis, P.; Raskob, W.; Melintescu, A.

    2008-07-15

    In this paper, some aspects of recent progress in tritium radioecology and dosimetry are presented, with emphasis on atmospheric releases to terrestrial ecosystems. The processes involved in tritium transfer through the environment are discussed, together with the current status of environmental tritium models. Topics include the deposition and reemission of HT and HTO, models for the assessment of routine and accidental HTO emissions, a new approach to modeling the dynamics of tritium in mammals, the dose consequences of tritium releases and aspects of human dosimetry. The need for additional experimental data is identified, together with the attributes that would be desirable in the next generation of tritium codes. (authors)

  20. SNL RML recommended dosimetry cross section compendium

    SciTech Connect

    Griffin, P.J.; Kelly, J.G.; Luera, T.F.; VanDenburg, J.

    1993-11-01

    A compendium of dosimetry cross sections is presented for use in the characterization of fission reactor spectrum and fluence. The contents of this cross section library are based upon the ENDF/B-VI and IRDF-90 cross section libraries and are recommended as a replacement for the DOSCROS84 multigroup library that is widely used by the dosimetry community. Documentation is provided on the rationale for the choice of the cross sections selected for inclusion in this library and on the uncertainty and variation in cross sections presented by state-of-the-art evaluations.

  1. Time to demand dosimetry for molecular radiotherapy?

    PubMed Central

    Guy, M J

    2015-01-01

    Molecular radiotherapy (MRT) has been used clinically for around 75 years. Despite this long history of clinical use, there is no established dosimetry practice for calculating the absorbed dose delivered to tumour targets or to organs at risk. As a result, treatment protocols have often evolved based on experience with relatively small numbers of patients, each receiving a similar administered activity but, potentially, widely varying doses. This is in stark contrast to modern external-beam radiotherapy practice. This commentary describes some of the barriers to MRT dosimetry and gives some opinions on the way forward. PMID:25571916

  2. On the uncertainties of photon mass energy-absorption coefficients and their ratios for radiation dosimetry

    NASA Astrophysics Data System (ADS)

    Andreo, Pedro; Burns, David T.; Salvat, Francesc

    2012-04-01

    A systematic analysis of the available data has been carried out for mass energy-absorption coefficients and their ratios for air, graphite and water for photon energies between 1 keV and 2 MeV, using representative kilovoltage x-ray spectra for mammography and diagnostic radiology below 100 kV, and for 192Ir and 60Co gamma-ray spectra. The aim of this work was to establish ‘an envelope of uncertainty’ based on the spread of the available data. Type A uncertainties were determined from the results of Monte Carlo (MC) calculations with the PENELOPE and EGSnrc systems, yielding mean values for µen/ρ with a given statistical standard uncertainty. Type B estimates were based on two groupings. The first grouping consisted of MC calculations based on a similar implementation but using different data and/or approximations. The second grouping was formed by various datasets, obtained by different authors or methods using the same or different basic data, and with different implementations (analytical, MC-based, or a combination of the two); these datasets were the compilations of NIST, Hubbell, Johns-Cunningham, Attix and Higgins, plus MC calculations with PENELOPE and EGSnrc. The combined standard uncertainty, uc, for the µen/ρ values for the mammography x-ray spectra is 2.5%, decreasing gradually to 1.6% for kilovoltage x-ray spectra up to 100 kV. For 60Co and 192Ir, uc is approximately 0.1%. The Type B uncertainty analysis for the ratios of µen/ρ values includes four methods of analysis and concludes that for the present data the assumption that the data interval represents 95% confidence limits is a good compromise. For the mammography x-ray spectra, the combined standard uncertainties of (µen/ρ)graphite,air and (µen/ρ)graphite,water are 1.5%, and 0.5% for (µen/ρ)water,air, decreasing gradually down to uc = 0.1% for the three µen/ρ ratios for the gamma-ray spectra. The present estimates are shown to coincide well with those of Hubbell (1977 Rad. Res

  3. Water calorimetry-based radiation dosimetry in iridium-192 brachytherapy and proton therapy

    NASA Astrophysics Data System (ADS)

    Sarfehnia, Arman

    The aim of this work is to develop and evaluate a primary standard for HDR 192Ir brachytherapy sources as well as for active spot scanning proton radiotherapy beams based on stagnant 4 °C water calorimetry. The measurements were performed using an in-house built water calorimeter and a parallel-plate calorimeter vessel. The dose measurement results of the McGill calorimeter were validated in high energy photon beams against Canada's national established primary standard at the NRC. The measurements in brachytherapy were performed with a spring-loaded catheter holder which allowed for the 192Ir source to come directly inside the water calorimeter. The COMSOL MULTIPHYSICS(TM) software was used to solve the heat transport equation numerically for a detailed geometrical model of our experimental setup. In brachytherapy, reference dosimetry protocols were also developed and used to measure the dose to water directly using thimble type ionization chambers and Gafchromic films with traceable 60Co (or higher energy photons) calibration factor. Based on water calorimetry standard, we measured an absolute dose rate to water of 361+/-7 microGy/(h·U) at 55 mm source-to-detector separation. The 1.9 % uncertainty on water calorimetry results is in contrast with the current recommended AAPM TG-43 protocol that achieves at best an uncertainty (k=1) of 2.5 % based on an indirect dose to water measurement technique. All measurement results from water calorimetry, ion chamber, film, and TG-43 agreed to within 0.83 %. We achieved an overall dose uncertainty of 0.4 % and 0.6 % for scattered and scanned proton radiation water calorimetry, respectively. The water calorimetry absorbed dose to water results agreed with those obtained through the currently recommended IAEA TRS-398 protocol (measurements made using an ionization chamber with a 60Co calibration factor) to better than 0.14 % and 0.32 % in scattered and scanned proton beams, respectively. In conclusion, this work forms the

  4. Passive dosimetry aboard the Mir Orbital Station: internal measurements

    NASA Technical Reports Server (NTRS)

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

    2002-01-01

    Passive radiation dosimeters were exposed aboard the Mir Orbital Station over a substantial portion of the solar cycle in order to measure the change in dose and dose equivalent rates as a function of time. During solar minimum, simultaneous measurements of the radiation environment throughout the habitable volume of the Mir were made using passive dosimeters in order to investigate the effect of localized shielding on dose and dose equivalent. The passive dosimeters consisted of a combination of thermoluminescent detectors to measure absorbed dose and CR-39 PNTDs to measure the linear energy transfer (LET) spectrum from charged particles of LET infinity H2O > or = 5 keV/micrometers. Results from the two detector types were then combined to yield mean total dose rate, mean dose equivalent rate, and average quality factor. Contrary to expectations, both dose and dose equivalent rates measured during May-October 1991 near solar maximum were higher than similar measurements carried out in 1996-1997 during solar minimum. The elevated dose and dose equivalent rates measured in 1991 were probably due to a combination of intense solar activity, including a large solar particle event on 9 June 1991, and the temporary trapped radiation belt created in the slot region by the solar particle event and ensuing magnetic storm of 24 March 1991. During solar minimum, mean dose and dose equivalent rates were found to vary by factors of 1.55 and 1.37, respectively, between different locations through the interior of Mir. More heavily shielded locations tended to yield lower total dose and dose equivalent rates, but higher average quality factor than did more lightly shielding locations. However, other factors such as changes in the immediate shielding environment surrounding a given detector location, changes in the orientation of the Mir relative to its velocity vector, and changes in the altitude of the station also contributed to the variation. Proton and neutron-induced target fragment secondaries, not primary galactic cosmic rays, were found to dominate the LET spectrum above 100 keV/micrometers. This indicates that in low earth orbit, trapped protons in the South Atlantic Anomaly are responsible for the major fraction of the total dose equivalent. c2002 Elsevier Science Ltd. All rights reserved.

  5. Passive dosimetry aboard the Mir Orbital Station: internal measurements.

    PubMed

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

    2002-10-01

    Passive radiation dosimeters were exposed aboard the Mir Orbital Station over a substantial portion of the solar cycle in order to measure the change in dose and dose equivalent rates as a function of time. During solar minimum, simultaneous measurements of the radiation environment throughout the habitable volume of the Mir were made using passive dosimeters in order to investigate the effect of localized shielding on dose and dose equivalent. The passive dosimeters consisted of a combination of thermoluminescent detectors to measure absorbed dose and CR-39 PNTDs to measure the linear energy transfer (LET) spectrum from charged particles of LET infinity H2O > or = 5 keV/micrometers. Results from the two detector types were then combined to yield mean total dose rate, mean dose equivalent rate, and average quality factor. Contrary to expectations, both dose and dose equivalent rates measured during May-October 1991 near solar maximum were higher than similar measurements carried out in 1996-1997 during solar minimum. The elevated dose and dose equivalent rates measured in 1991 were probably due to a combination of intense solar activity, including a large solar particle event on 9 June 1991, and the temporary trapped radiation belt created in the slot region by the solar particle event and ensuing magnetic storm of 24 March 1991. During solar minimum, mean dose and dose equivalent rates were found to vary by factors of 1.55 and 1.37, respectively, between different locations through the interior of Mir. More heavily shielded locations tended to yield lower total dose and dose equivalent rates, but higher average quality factor than did more lightly shielding locations. However, other factors such as changes in the immediate shielding environment surrounding a given detector location, changes in the orientation of the Mir relative to its velocity vector, and changes in the altitude of the station also contributed to the variation. Proton and neutron-induced target fragment secondaries, not primary galactic cosmic rays, were found to dominate the LET spectrum above 100 keV/micrometers. This indicates that in low earth orbit, trapped protons in the South Atlantic Anomaly are responsible for the major fraction of the total dose equivalent. PMID:12440436

  6. Response of LiF:Mg,Ti thermoluminescent dosimeters at photon energies relevant to the dosimetry of brachytherapy (<1 MeV)

    SciTech Connect

    Tedgren, Aasa Carlsson; Hedman, Angelica; Grindborg, Jan-Erik; Carlsson, Gudrun Alm

    2011-10-15

    Purpose: High energy photon beams are used in calibrating dosimeters for use in brachytherapy since absorbed dose to water can be determined accurately and with traceability to primary standards in such beams, using calibrated ion chambers and standard dosimetry protocols. For use in brachytherapy, beam quality correction factors are needed, which include corrections for differences in mass energy absorption properties between water and detector as well as variations in detector response (intrinsic efficiency) with radiation quality, caused by variations in the density of ionization (linear energy transfer (LET) -distributions) along the secondary electron tracks. The aim of this work was to investigate experimentally the detector response of LiF:Mg,Ti thermoluminescent dosimeters (TLD) for photon energies below 1 MeV relative to {sup 60}Co and to address discrepancies between the results found in recent publications of detector response. Methods: LiF:Mg,Ti dosimeters of formulation MTS-N Poland were irradiated to known values of air kerma free-in-air in x-ray beams at tube voltages 25-250 kV, in {sup 137}Cs- and {sup 60}Co-beams at the Swedish Secondary Standards Dosimetry Laboratory. Conversions from air kerma free-in-air into values of mean absorbed dose in the dosimeters in the actual irradiation geometries were made using EGSnrc Monte Carlo simulations. X-ray energy spectra were measured or calculated for the actual beams. Detector response relative to that for {sup 60}Co was determined at each beam quality. Results: An increase in relative response was seen for all beam qualities ranging from 8% at tube voltage 25 kV (effective energy 13 keV) to 3%-4% at 250 kV (122 keV effective energy) and {sup 137}Cs with a minimum at 80 keV effective energy (tube voltage 180 kV). The variation with effective energy was similar to that reported by Davis et al.[Radiat. Prot. Dosim. 106, 33-43 (2003)] with our values being systematically lower by 2%-4%. Compared to the

  7. Personnel radiation dosimetry symposium: program and abstracts

    SciTech Connect

    Not Available

    1984-10-01

    The purpose was to provide applied and research dosimetrists with sufficient information to evaluate the status and direction of their programs relative to the latest guidelines and techniques. A technical program was presented concerning experience, requirements, and advances in gamma, beta, and neutron personnel dosimetry.

  8. 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...

  9. 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...

  10. 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...

  11. 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...

  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. 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)

  14. Dosimetry implant for treating restenosis and hyperplasia

    DOEpatents

    Srivastava, Suresh; Gonzales, Gilbert R; Howell, Roger W; Bolch, Wesley E; Adzic, Radoslav

    2014-09-16

    The present invention discloses a method of selectively providing radiation dosimetry to a subject in need of such treatment. The radiation is applied by an implant comprising a body member and .sup.117mSn electroplated at selected locations of the body member, emitting conversion electrons absorbed immediately adjacent selected locations while not affecting surrounding tissue outside of the immediately adjacent area.

  15. Protocol for emergency EPR dosimetry in fingernails

    Technology Transfer Automated Retrieval System (TEKTRAN)

    There is an increased need for after-the fact dosimetry because of the high risk of radiation exposures due to terrorism or accidents. In case of such an event, a method is needed to make measurements of dose in a large number of individuals rapidly and with sufficient accuracy to facilitate effect...

  16. 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.

  17. 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

  18. Evaluation of GAFCHROMIC registered EBT film for CyberKnife registered dosimetry

    SciTech Connect

    Wilcox, Ellen E.; Daskalov, George M.

    2007-06-15

    External beam therapy (EBT) GAFCHROMIC registered film is evaluated for dosimetry and characterization of the CyberKnife registered radiation beams. Percentage depth doses, lateral beam profiles, and output factors are measured in solid water using EBT GAFCHROMIC registered film (International Specialty Products, Wayne, NJ) for the 6 MV radiation beams of diameter 5 to 60 mm produced by the CyberKnife registered (Accuray, Sunnyvale, CA). The data are compared to those measured with the PTW 60008 diode and the Wellhofer CC01 ion chamber in water. For the small radiation field sizes used in stereotactic radiosurgery, lateral electronic disequilibrium and steep dose gradients exist in a large portion of these fields, requiring the use of high-resolution measurement techniques. For small beams, the detector size approaches the dimensions of the beam and adversely affects measurement accuracy in regions where the gradient varies across the detector. When film is the detector, the scanning system is usually the resolution-limiting component. Radiographic films based upon silver halide (AgH) emulsions are widely used for relative dosimetry of external radiation treatment beams in the megavoltage energy range, because of their good spatial resolution and capability to provide integrated dosimetry over two dimensions. Film dosimetry, however, has drawbacks due to its steep energy dependence at low photon energies as well as film processor and densitometer artifacts. EBT radiochromic film, introduced in 2004 specifically for IMRT dosimetry, may be a detector of choice for the characterization of small radiosurgical beams, because of its near-tissue equivalence, radiation beam energy independence, high spatial resolution, and self developing properties. For radiation beam sizes greater than 10 mm, the film measurements were identical to those of the diode and ion chamber. For the smaller beam diameters of 7.5 and 5 mm, however, there were differences in the data measured with

  19. Monte Carlo verification of polymer gel dosimetry applied to radionuclide therapy: a phantom study

    NASA Astrophysics Data System (ADS)

    Gear, J. I.; Charles-Edwards, E.; Partridge, M.; Flux, G. D.

    2011-11-01

    This study evaluates the dosimetric performance of the polymer gel dosimeter 'Methacrylic and Ascorbic acid in Gelatin, initiated by Copper' and its suitability for quality assurance and analysis of I-131-targeted radionuclide therapy dosimetry. Four batches of gel were manufactured in-house and sets of calibration vials and phantoms were created containing different concentrations of I-131-doped gel. Multiple dose measurements were made up to 700 h post preparation and compared to equivalent Monte Carlo simulations. In addition to uniformly filled phantoms the cross-dose distribution from a hot insert to a surrounding phantom was measured. In this example comparisons were made with both Monte Carlo and a clinical scintigraphic dosimetry method. Dose-response curves generated from the calibration data followed a sigmoid function. The gels appeared to be stable over many weeks of internal irradiation with a delay in gel response observed at 29 h post preparation. This was attributed to chemical inhibitors and slow reaction rates of long-chain radical species. For this reason, phantom measurements were only made after 190 h of irradiation. For uniformly filled phantoms of I-131 the accuracy of dose measurements agreed to within 10% when compared to Monte Carlo simulations. A radial cross-dose distribution measured using the gel dosimeter compared well to that calculated with Monte Carlo. Small inhomogeneities were observed in the dosimeter attributed to non-uniform mixing of monomer during preparation. However, they were not detrimental to this study where the quantitative accuracy and spatial resolution of polymer gel dosimetry were far superior to that calculated using scintigraphy. The difference between Monte Carlo and gel measurements was of the order of a few cGy, whilst with the scintigraphic method differences of up to 8 Gy were observed. A manipulation technique is also presented which allows 3D scintigraphic dosimetry measurements to be compared to polymer

  20. 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

  1. 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.

  2. A comparison of the 60Co gamma radiation hardness, breakdown characteristics and the effect of SiN x capping on InAlN and AlGaN HEMTs for space applications

    NASA Astrophysics Data System (ADS)

    Smith, M. D.; O'Mahony, D.; Vitobello, F.; Muschitiello, M.; Costantino, A.; Barnes, A. R.; Parbrook, P. J.

    2016-02-01

    Electrical performance and stability of InAlN and AlGaN high electron mobility transistors (HEMTs) subjected 9.1 mrad of 60Co gamma radiation and off-state voltage step-stressing until breakdown are reported. Comparison with commercially available production-level AlGaN HEMT devices, which showed negligible drift in DC performance throughout all experiments, suggests degradation mechanisms must be managed and suppressed through development of advanced epitaxial and surface passivation techniques in order to fully exploit the robustness of the III-nitride material system. Of the research level devices without dielectric layer surface capping, InAlN HEMTs exhibited the greater stability compared with AlGaN under off-state bias stressing and gamma irradiation in terms of their DC characteristics, although AlGaN HEMTs had significantly higher breakdown voltages. The effect of plasma-enhanced chemical vapour deposition SiN x surface capping is explored, highlighting the sensitivity of InAlN HEMT performance to surface passivation techniques. InAlN-SiN x HEMTs suffered more from trap related degradation than AlGaN-SiN x devices in terms of radiation hardness and step-stress characteristics, attributed to an increased capturing of carriers in traps at the InAlN/SiN x interface.

  3. Microdosimetry of DNA conformations: relation between direct effect of (60)Co gamma rays and topology of DNA geometrical models in the calculation of A-, B- and Z-DNA radiation-induced damage yields.

    PubMed

    Semsarha, Farid; Raisali, Gholamreza; Goliaei, Bahram; Khalafi, Hossein

    2016-05-01

    In order to obtain the energy deposition pattern of ionizing radiation in the nanometric scale of genetic material and to investigate the different sensitivities of the DNA conformations, direct effects of (60)Co gamma rays on the three A, B and Z conformations of DNA have been studied. For this purpose, single-strand breaks (SSB), double-strand breaks (DSB), base damage (BD), hit probabilities and three microdosimetry quantities (imparted energy, mean chord length and lineal energy) in the mentioned DNA conformations have been calculated and compared by using GEometry ANd Tracking 4 (Geant4) toolkit. The results show that A-, B- and Z-DNA conformations have the highest yields of DSB (1.2 Gy(-1) Gbp(-1)), SSB (25.2 Gy(-1) Gbp(-1)) and BD (4.81 Gy(-1) Gbp(-1)), respectively. Based on the investigation of direct effects of radiation, it can be concluded that the DSB yield is largely correlated to the topological characteristics of DNA models, although the SSB yield is not. Moreover, according to the comparative results of the present study, a reliable candidate parameter for describing the relationship between DNA damage yields and geometry of DNA models in the theoretical radiation biology research studies would be the mean chord length (4 V/S) of the models. PMID:26984469

  4. Determination of the Sensibility Factors for TLD-100 Powder on the Energy of X-Ray of 50, 250 kVp; 192Ir, 137Cs and 60Co

    SciTech Connect

    Loaiza, Sandra P.; Alvarez, Jose T.

    2006-09-08

    TLD-100 powder is calibrated in terms of absorbed dose to water Dw, using the protocols AAPM TG61, AAPM TG43 and IAEA-TRS 398, for the energy of RX 50, 250 kVp, 137Cs and 60Co respectively. The calibration curves, TLD Response R versus Dw, are fitted by weighted least square by a quadratic polynomials; which are validated with the lack of fit and the Anderson-Darling normality test. The slope of these curves corresponds to the sensibility factor: Fs R/DW, [Fs] = nC Gy-1. The expanded uncertainties U's for these factors are obtained from the ANOVA tables. Later, the Fs' values are interpolated using the effective energy hvefec for the 192Ir. The SSDL sent a set of capsules with powder TLD-100 for two Hospitals. These irradiated them a nominal dose of Dw = 2 Gy. The results determined at SSDL are: for the Hospital A the Dw is overestimated in order to 4.8% and the Hospital B underestimates it in the range from -1.4% to -17.5%.

  5. Five-Year ALARA Review of Dosimetry Results 1 January 2010 through 31 December 2014.

    SciTech Connect

    Paulus, Luke R.

    2015-06-01

    A review of dosimetry results from 1 January 2010 through 31 December 2014 was conducted to demonstrate that radiation protection methods used are compliant with regulatory limits and conform to the philosophy to keep exposures to radiation As Low As is Reasonably Achievable (ALARA). This included a review and evaluation of personnel dosimetry (external and internal) results at Sandia National Laboratories, New Mexico as well as at Sandia National Laboratories, California. Additionally, results of environmental monitoring efforts at Sandia National Laboratories, New Mexico were reviewed. ALARA is a philosophical approach to radiation protection by managing and controlling radiation exposures (individual and collective) to the work force and to the general public to levels that are As Low As is Reasonably Achievable taking social, technical, economic, practical, and public policy considerations into account. ALARA is not a dose limit but a process which has the objective of attaining doses as far below applicable dose limits As Low As is Reasonably Achievable.

  6. Five-Year ALARA Review of Dosimetry Results 1 January 2009 through 31 December 2013.

    SciTech Connect

    Paulus, Luke R

    2014-08-01

    A review of dosimetry results from 1 January 2009 through 31 December 2013 was conducted to demonstrate that radiation protection methods used are compliant with regulatory limits and conform to the ALARA philosophy. This included a review and evaluation of personnel dosimetry (external and internal) results at Sandia National Laboratories, New Mexico as well as at Sandia National Laboratories, California. Additionally, results of environmental monitoring efforts at Sandia National Laboratories, New Mexico were reviewed. ALARA is a philosophical approach to radiation protection by managing and controlling radiation exposures (individual and collective) to the work force and to the general public to levels that are As Low As is Reasonably Achievable taking social, technical, economic, practical, and public policy considerations into account. ALARA is not a dose limit but a process which has the objective of attaining doses as far below applicable dose limits As Low As is Reasonably Achievable.

  7. 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.

  8. Study of the replacement correction factors for ionization chamber dosimetry by Monte Carlo simulations

    NASA Astrophysics Data System (ADS)

    Wang, Lilie

    In ionization chamber radiation dosimetry, the introduction of the ion chamber into medium will unavoidably distort the radiation field near the chamber because the chamber cavity material (air) is different from the medium. A replacement correction factor, Prepl was introduced in order to correct the chamber readings to give an accurate radiation dose in the medium without the presence of the chamber. Generally it is very hard to measure the values of Prepl since they are intertwined with the chamber wall effect. In addition, the P repl values always come together with the stopping-power ratio of the two media involved. This makes the problem of determining the P repl values even more complicated. Monte Carlo simulation is an ideal method to investigate the replacement correction factors. In this study, four different methods of calculating the values of Prepl by Monte Carlo simulation are discussed. Two of the methods are designated as 'direct' methods in the sense that the evaluation of the stopping-power ratio is not necessary. The systematic uncertainties of the two direct methods are estimated to be about 0.1-0.2% which comes from the ambiguous definition of the energy cutoff Delta used in the Spencer-Attix cavity theory. The two direct methods are used to calculate the values of P repl for both plane-parallel chambers and cylindrical thimble chambers in either electron beams or photon beams. The calculation results are compared to measurements. For electron beams, good agreements are obtained. For thimble chambers in photon beams, significant discrepancies are observed between calculations and measurements. The experiments are thus investigated and the procedures are simulated by the Monte Carlo method. It is found that the interpretation of the measured data as the replacement correction factors in dosimetry protocols are not correct. In applying the calculation to the BIPM graphite chamber in a 60Co beam, the calculated values of P repl differ from those

  9. A Case Report: Cytogenetic Dosimetry after Accidental Radiation Exposure during (192)Ir Industrial Radiography Testing.

    PubMed

    Beinke, C; Ben-Shlomo, A; Abend, M; Port, M

    2015-07-01

    The accidental gamma radiation exposure of an industrial radiography worker and the cytogenetic examination of the worker's blood lymphocytes are described here. The exposure of the worker was due to a malfunction at the entrance into the depleted uranium-shielding device of a (192)Ir source during operation. Because the source was sealed no additional beta radiation exposure was assumed. The worker's thermoluminescent dosimeter indicated an absorbed dose of 0.078 Sv, which presumably took place in December 2013. No clinical symptoms were reported in the case history after the potential exposure to radiation. Four months after the incident it was decided that biological dosimetry using dicentric chromosome and micronucleus analysis would be performed to follow radiation protection aspects and to clarify the radiation dose uncertainties for the exposed worker. Micronucleus frequency was not increased above the laboratory's control value of micronucleus background frequency of unexposed individuals. However, the observed dicentric frequency (0.003 dicentric/cell) differs significantly from the laboratory's background level of dicentric chromosomes in unexposed individuals (0.0007 dicentric/cell). Dicentric analysis in 2,048 metaphase cells resulted in an estimated dose of no more than 0.181 Gy (95% upper confidence level), not less than 0.014 Gy (95% lower confidence level) and a mean dose of 0.066 Gy (photon-equivalent whole-body exposure) based on interpolation from the laboratory's calibration curve for (60)Co gamma radiation. Since overdispersion of dicentric chromosomes (u = 9.78) indicated a heterogeneous (partial-body) exposure, we applied the Dolphin method and estimated an exposure of 2.1 Sv affecting 21% of the body volume. Because the overdispersion of dicentric chromosomes was caused by only one heavily damaged cell containing two dicentrics, it is possible that this was an incidental finding. In summary, a radiation overexposure of the radiography worker

  10. TH-E-BRE-06: Challenges in the Dosimetry of Flattening Filter Free Beams

    SciTech Connect

    Czarnecki, D; Voigts-Rhetz, P von; Zink, K

    2014-06-15

    Purpose: In current dosimetry protocols [AAPM TG51, IAEA TRS-389] the beam quality correction factor kQ and the water-to-air restricted mass collision stopping-power ratio SPR are related to beam quality specifiers %dd(10){sub x} respectively TPR{sub 20,10} Determining kQ and SPR using these regular beam quality specifiers for conventional accelerators (WFF) and flattening filter free accelerators (FFF) similarly could lead to systemic bias.The influence of the flattening filter on the relationship between various beam quality specifiers and SPR respectively k{sub Q} was studied using Monte Carlo simulations with realistic beam sources. Methods: All Monte Carlo simulations were performed using the BEAMnrc/EGSnrc code system. Radiation transport through nine linear accelerator heads modeled according to technical drawings given by the manufactures and a {sup 60} Co therapy source was simulated with BEAMnrc and then used as a radiation source for further simulations. FFF beam sources were implemented by removing the fattening filter from the WFF model. SPR was calculated applying the user code SPRRZnrc. The mean photon energy below the accelerator head and the mean energies of photons and electrons at the measuring point within the water phantom were calculated using FLURZnrc. Dose calculations within a small water voxel and the thimble ionization chamber PTW-31010 in a water depth of 10 cm were made using the egs-chamber code. Results: SPR and k{sub Q} as a function of fluence spectra based beam quality specifiers as well as conventional beam quality specifiers differ systematically between FFF and WFF beams. According to the results the specifier %dd(10){sub x} revealed the smallest deviation (max. 0.4%) between FFF and WFF beams. Conclusion: The results show that %dd(10){sub x} is an acceptable beam quality specifier for FFF beams. Nevertheless the results confirm the expected bias between FFF and WFF beams which must by further investigated.

  11. Nuclear accident dosimetry studies at Los Alamos National Laboratory

    SciTech Connect

    Casson, W.H.; Buhl, T.E.; Upp, D.L.

    1995-12-01

    Two critical assemblies have been characterized at the Los Alamos Critical Experiments Facility (LACEF) for use in testing nuclear accident dosimeters and related devices. These device, Godiva IV and SHEBA II, have very different characteristics in both operation and emitted neutron energy spectra. The Godiva assembly is a bare metal fast burst device with a hard spectrum. This spectrum can be modified by use of several shields including steel, concrete, and plexiglas. The modified spectra vary in both average neutron energy and in the specific distribution of the neutron energies in the intermediate energy range. This makes for a very favorable test arrangement as the response ratios between different activation foils used in accident dosimeters are significantly altered such as the ratio between gold, copper, and sulfur elements. The SHEBA device is a solution assembly which has both a slow ramp and decay period and a much softer spectrum. The uncertainly introduced in the response of fast decay foils such as indium can therefore be evaluated into the test results. The neutron energy spectrum for each configuration was measured during low power operations with a multisphere system. These measurements were extended to high dose pulsed operation by use of TLDs moderated TLDs, and special activation techniques. The assemblies were used in the testing of several accident dosimetry devices in studies modeled after the Nuclear Accident Dosimetry Studies that were conducted at Oak Ridge National Laboratory for about 25 years using the Health Physics Research Reactor. It is our intention to conduct these studies approximately annually for the evaluation of the nuclear accident dosimeter systems currently in use within the DOE, alternative systems used internationally, and new dosimeter designs being developed or considered for field application. Participation in selected studies will be open to all participants.

  12. Space radiation dosimetry in low-Earth orbit and beyond

    NASA Technical Reports Server (NTRS)

    Benton, E. R.; Benton, E. V.

    2001-01-01

    Space radiation dosimetry presents one of the greatest challenges in the discipline of radiation protection. This is a result of both the highly complex nature of the radiation fields encountered in low-Earth orbit (LEO) and interplanetary space and of the constraints imposed by spaceflight on instrument design. This paper reviews the sources and composition of the space radiation environment in LEO as well as beyond the Earth's magnetosphere. A review of much of the dosimetric data that have been gathered over the last four decades of human space flight is presented. The different factors affecting the radiation exposures of astronauts and cosmonauts aboard the International Space Station (ISS) are emphasized. Measurements made aboard the Mir Orbital Station have highlighted the importance of both secondary particle production within the structure of spacecraft and the effect of shielding on both crew dose and dose equivalent. Roughly half the dose on ISS is expected to come from trapped protons and half from galactic cosmic rays (GCRs). The dearth of neutron measurements aboard LEO spacecraft and the difficulty inherent in making such measurements have led to large uncertainties in estimates of the neutron contribution to total dose equivalent. Except for a limited number of measurements made aboard the Apollo lunar missions, no crew dosimetry has been conducted beyond the Earth's magnetosphere. At the present time we are forced to rely on model-based estimates of crew dose and dose equivalent when planning for interplanetary missions, such as a mission to Mars. While space crews in LEO are unlikely to exceed the exposure limits recommended by such groups as the NCRP, dose equivalents of the same order as the recommended limits are likely over the course of a human mission to Mars. c2001 Elsevier Science B.V. All rights reserved.

  13. Space radiation dosimetry in low-Earth orbit and beyond.

    PubMed

    Benton, E R; Benton, E V

    2001-09-01

    Space radiation dosimetry presents one of the greatest challenges in the discipline of radiation protection. This is a result of both the highly complex nature of the radiation fields encountered in low-Earth orbit (LEO) and interplanetary space and of the constraints imposed by spaceflight on instrument design. This paper reviews the sources and composition of the space radiation environment in LEO as well as beyond the Earth's magnetosphere. A review of much of the dosimetric data that have been gathered over the last four decades of human space flight is presented. The different factors affecting the radiation exposures of astronauts and cosmonauts aboard the International Space Station (ISS) are emphasized. Measurements made aboard the Mir Orbital Station have highlighted the importance of both secondary particle production within the structure of spacecraft and the effect of shielding on both crew dose and dose equivalent. Roughly half the dose on ISS is expected to come from trapped protons and half from galactic cosmic rays (GCRs). The dearth of neutron measurements aboard LEO spacecraft and the difficulty inherent in making such measurements have led to large uncertainties in estimates of the neutron contribution to total dose equivalent. Except for a limited number of measurements made aboard the Apollo lunar missions, no crew dosimetry has been conducted beyond the Earth's magnetosphere. At the present time we are forced to rely on model-based estimates of crew dose and dose equivalent when planning for interplanetary missions, such as a mission to Mars. While space crews in LEO are unlikely to exceed the exposure limits recommended by such groups as the NCRP, dose equivalents of the same order as the recommended limits are likely over the course of a human mission to Mars. PMID:11863032

  14. An investigation of false positive dosimetry results

    SciTech Connect

    Lewandowski, M.A.; Davis, S.A.; Goff, T.E.; Wu, C.F.

    1996-12-31

    The Waste Isolation Pilot Plant (WIPP) is a facility designed for the demonstration of the safe disposal of transuranic waste. Currently, the radiation source term is confined to sealed calibration and check sources since WIPP has not received waste for disposal. For several years the WIPP Dosimetry Group has operated a Harshaw Model 8800C reader to analyze Harshaw 8801-7776 thermoluminescent cards (3 TLD-700 and 1 TLD-600) with 8805 holder. The frequency of false positive results for quarterly dosimeter exchanges is higher than desired by the Dosimetry Group management. Initial observations suggested that exposure to intense ambient sunlight may be responsible for the majority of the false positive readings for element 3. A study was designed to investigate the possibility of light leaking through the holder and inducing a signal in element 3. This paper discusses the methods and results obtained, with special emphasis placed on recommendations to reduce the frequency of light-induced false positive readings.

  15. Neutron dosimetry using optically stimulated luminescence

    NASA Astrophysics Data System (ADS)

    Miller, S. D.; Eschbach, P. A.

    1991-06-01

    The addition of thermoluminescent (TL) materials within hydrogenous matrices to detect neutron induced proton recoils for radiation dosimetry is a well known concept. Previous attempts to implement this technique have met with limited success, primarily due to the high temperatures required for TL readout and the low melting temperatures of hydrogen-rich plastics. Research in recent years PNL has produced a new Optically Stimulated Luminescence (OSL) technique known as the Cooled Optically Stimulated Luminescence (COSL) that offers, for the first time, the capability of performing extremely sensitive radiation dosimetry at low temperatures. In addition to its extreme sensitivity, the COSL technique offers multiple readout capability, limited fading in a one year period, and the capability of analyzing single grains within a hydrogenous matrix.

  16. Passive particle dosimetry. [silver halide crystal growth

    NASA Technical Reports Server (NTRS)

    Childs, C. B.

    1977-01-01

    Present methods of dosimetry are reviewed with emphasis on the processes using silver chloride crystals for ionizing particle dosimetry. Differences between the ability of various crystals to record ionizing particle paths are directly related to impurities in the range of a few ppm (parts per million). To understand the roles of these impurities in the process, a method for consistent production of high purity silver chloride, and silver bromide was developed which yields silver halides with detectable impurity content less than 1 ppm. This high purity silver chloride was used in growing crystals with controlled doping. Crystals were grown by both the Czochalski method and the Bridgman method, and the Bridgman grown crystals were used for the experiments discussed. The distribution coefficients of ten divalent cations were determined for the Bridgman crystals. The best dosimeters were made with silver chloride crystals containing 5 to 10 ppm of lead; other impurities tested did not produce proper dosimeters.

  17. Absolute and relative dosimetry for ELIMED

    SciTech Connect

    Cirrone, G. A. P.; Schillaci, F.; Scuderi, V.; Cuttone, G.; Candiano, G.; Musumarra, A.; Pisciotta, P.; Romano, F.; Carpinelli, M.; Presti, D. Lo; Raffaele, L.; Tramontana, A.; Cirio, R.; Sacchi, R.; Monaco, V.; Marchetto, F.; Giordanengo, S.

    2013-07-26

    The definition of detectors, methods and procedures for the absolute and relative dosimetry of laser-driven proton beams is a crucial step toward the clinical use of this new kind of beams. Hence, one of the ELIMED task, will be the definition of procedures aiming to obtain an absolute dose measure at the end of the transport beamline with an accuracy as close as possible to the one required for clinical applications (i.e. of the order of 5% or less). Relative dosimetry procedures must be established, as well: they are necessary in order to determine and verify the beam dose distributions and to monitor the beam fluence and the energetic spectra during irradiations. Radiochromic films, CR39, Faraday Cup, Secondary Emission Monitor (SEM) and transmission ionization chamber will be considered, designed and studied in order to perform a fully dosimetric characterization of the ELIMED proton beam.

  18. Neutron dosimetry using optically stimulated luminescence

    SciTech Connect

    Miller, S.D.; Eschbach, P.A.

    1991-06-01

    The addition of thermoluminescent (TL) materials within hydrogenous matrices to detect neutron-induced proton recoils for radiation dosimetry is a well-known concept. Previous attempts to implement this technique have met with limited success, primarily due to the high temperatures required for TL readout and the low melting temperatures of hydrogen-rich plastics. Research in recent years at Pacific Northwest laboratories (PNL) has produced a new Optically Stimulated Luminescence (OSL) technique known as the Cooled Optically Stimulated Luminescence (COSL) that offers, for the first time, the capability of performing extremely sensitive radiation dosimetry at low temperatures. In addition to its extreme sensitivity, the COSL technique offers multiple readout capability, limited fading in a one-year period, and the capability of analyzing single grains within a hydrogenous matrix. 4 refs., 10 figs.

  19. Trigeminal neuralgia treatment dosimetry of the Cyberknife

    SciTech Connect

    Ho, Anthony; Lo, Anthony T.; Dieterich, Sonja; Soltys, Scott G.; Gibbs, Iris C.; Chang, Steve G.; Adler, John R.

    2012-04-01

    There are 2 Cyberknife units at Stanford University. The robot of 1 Cyberknife is positioned on the patient's right, whereas the second is on the patient's left. The present study examines whether there is any difference in dosimetry when we are treating patients with trigeminal neuralgia when the target is on the right side or the left side of the patient. In addition, we also study whether Monte Carlo dose calculation has any effect on the dosimetry. We concluded that the clinical and dosimetric outcomes of CyberKnife treatment for trigeminal neuralgia are independent of the robot position. Monte Carlo calculation algorithm may be useful in deriving the dose necessary for trigeminal neuralgia treatments.

  20. 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.

  1. Simple optical theory for light dosimetry during PDT (Invited Paper)

    NASA Astrophysics Data System (ADS)

    Jacques, Steven L.

    1992-06-01

    Photons are one of the three major reactants in the photodynamic reaction that yields toxic photoproduct for cell killing. Dosimetry of light is a major concern when planning a photodynamic therapy (PDT) protocol. This paper presents a very simple approach toward the tissue optics with a practical conclusion about how tissue optics affects planning of day-to-day PDT dosimetry. The paper does not address all the complexities of real tissue dosimetry, such as heterogeneous tissues, variable absorption due to changing tissue blood content, and variable tissue oxygen levels. The paper outlines the optical behavior in a homogeneous tissue, which is a starting point for understanding light dosimetry.

  2. 3D dosimetry fundamentals: gels and plastics

    NASA Astrophysics Data System (ADS)

    Lepage, M.; Jordan, K.

    2010-11-01

    Many different materials have been developed for 3D radiation dosimetry since the Fricke gel dosimeter was first proposed in 1984. This paper is intended as an entry point into these materials where we provide an overview of the basic principles for the most explored materials. References to appropriate sources are provided such that the reader interested in more details can quickly find relevant information.

  3. 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

  4. Software tool for portal dosimetry research.

    PubMed

    Vial, P; Hunt, P; Greer, P B; Oliver, L; Baldock, C

    2008-09-01

    This paper describes a software tool developed for research into the use of an electronic portal imaging device (EPID) to verify dose for intensity modulated radiation therapy (IMRT) beams. A portal dose image prediction (PDIP) model that predicts the EPID response to IMRT beams has been implemented into a commercially available treatment planning system (TPS). The software tool described in this work was developed to modify the TPS PDIP model by incorporating correction factors into the predicted EPID image to account for the difference in EPID response to open beam radiation and multileaf collimator (MLC) transmitted radiation. The processes performed by the software tool include; i) read the MLC file and the PDIP from the TPS, ii) calculate the fraction of beam-on time that each point in the IMRT beam is shielded by MLC leaves, iii) interpolate correction factors from look-up tables, iv) create a corrected PDIP image from the product of the original PDIP and the correction factors and write the corrected image to file, v) display, analyse, and export various image datasets. The software tool was developed using the Microsoft Visual Studio.NET framework with the C# compiler. The operation of the software tool was validated. This software provided useful tools for EPID dosimetry research, and it is being utilised and further developed in ongoing EPID dosimetry and IMRT dosimetry projects. PMID:18946980

  5. Radiation dosimetry and spectrometry with superheated emulsions

    NASA Astrophysics Data System (ADS)

    d'Errico, Francesco

    2001-09-01

    Detectors based on emulsions of overexpanded halocarbon droplets in tissue equivalent aqueous gels or soft polymers, known as "superheated drop detectors" or "bubble (damage) detectors", have been used in radiation detection, dosimetry and spectrometry for over two decades. Recent technological advances have led to the introduction of several instruments for individual and area monitoring: passive integrating meters based on the optical or volumetric registration of the bubbles, and active counters detecting bubble nucleations acoustically. These advances in the instrumentation have been matched by the progress made in the production of stable and well-specified emulsions of superheated droplets. A variety of halocarbons are employed in the formulation of the detectors, and this permits a wide range of applications. In particular, halocarbons with a moderate degree of superheat, i.e. a relatively small difference between their operating temperature and boiling point, can be used in neutron dosimetry and spectrometry since they are only nucleated by energetic heavy ions such as those produced by fast neutrons. More recently, halocarbons with an elevated degree of superheat have been utilised to produce emulsions that nucleate with much smaller energy deposition and detect low linear energy transfer radiations, such as photons and electrons. This paper reviews the detector physics of superheated emulsions and their applications in radiation measurements, particularly in neutron dosimetry and spectrometry.

  6. Effects of temperature variation on MOSFET dosimetry.

    PubMed

    Cheung, Tsang; Butson, Martin J; Yu, Peter K N

    2004-07-01

    This note investigates temperature effects on dosimetry using a metal oxide semiconductor field effect transistor (MOSFET) for radiotherapy x-ray treatment. This was performed by analysing the dose response and threshold voltage outputs for MOSFET dosimeters as a function of ambient temperature. Results have shown that the clinical semiconductor dosimetry system (CSDS) MOSFET provides stable dose measurements with temperatures varying from 15 degrees C up to 40 degrees C. Thus standard irradiations performed at room temperature can be directly compared to in vivo dose assessments performed at near body temperature without a temperature correction function. The MOSFET dosimeter threshold voltage varies with temperature and this level is dependent on the dose history of the MOSFET dosimeter. However, the variation can be accounted for in the measurement method. For accurate dosimetry, the detector should be placed for approximately 60 s on a patient to allow thermal equilibrium before measurements are taken with the final reading performed whilst still attached to the patient or conversely left for approximately 120 s after removal from the patient if initial readout was measured at room temperature to allow temperature equilibrium to be established. PMID:15285264

  7. In vivo dosimetry in external beam radiotherapy

    SciTech Connect

    Mijnheer, Ben; Beddar, Sam; Izewska, Joanna; Reft, Chester

    2013-07-15

    In vivo dosimetry (IVD) is in use in external beam radiotherapy (EBRT) to detect major errors, to assess clinically relevant differences between planned and delivered dose, to record dose received by individual patients, and to fulfill legal requirements. After discussing briefly the main characteristics of the most commonly applied IVD systems, the clinical experience of IVD during EBRT will be summarized. Advancement of the traditional aspects of in vivo dosimetry as well as the development of currently available and newly emerging noninterventional technologies are required for large-scale implementation of IVD in EBRT. These new technologies include the development of electronic portal imaging devices for 2D and 3D patient dosimetry during advanced treatment techniques, such as IMRT and VMAT, and the use of IVD in proton and ion radiotherapy by measuring the decay of radiation-induced radionuclides. In the final analysis, we will show in this Vision 20/20 paper that in addition to regulatory compliance and reimbursement issues, the rationale for in vivo measurements is to provide an accurate and independent verification of the overall treatment procedure. It will enable the identification of potential errors in dose calculation, data transfer, dose delivery, patient setup, and changes in patient anatomy. It is the authors' opinion that all treatments with curative intent should be verified through in vivo dose measurements in combination with pretreatment checks.

  8. Dosimetry for members of the extended Techa River cohort

    SciTech Connect

    Anspaugh, L R.; Degteva, M. O.; Vorobiova, M I.; Mokrov, Y; Napier, Bruce A.

    2006-10-01

    The undersigned and colleagues are creators and a critic of the Techa River Dosimetry System-2000 (TRDS-2000), which was the subject of a recent article by Balonov et al. This article presented a consensus on a review of the TRDS-2000 achieved following a workshop in December 2003. The TRDS-2000 was used to derive risk coefficients for members of an unselected general population exposed to moderate doses of radiation at low dose rates on the Techa River in the 1950s. Because it is now more than two years since the workshop, a significant number of events have transpired, and the purpose of this letter is to inform readers of current developments. As noted in Balonov et al., much of the concern about the dosimetric and epidemiologic investigation of the Extended Techa River Cohort was heightened by a preliminary derivation of risk estimates that were higher than those derived from study of the survivors of the atomic bombings in Japan, but not significantly different. Similar results showing risks for leukemia and solid cancers about 50% higher than those in the Japanese survivors have now been published. These unexpected results have raised the issue of the validity of the doses being calculated with the TRDS-2000. Much of the honest differences of opinion among the undersigned about the TRDS-2000 is concerned with the accuracy and precision of the releases to the Techa River during the 1949-1951 period. Balonov et al. recommended many steps to investigate further information available on the releases, and to take other steps to resolve differences in opinion. As noted by Balonov et al., one of the more promising was a proposed study (with funding requested from the International Science and Technology Center) for the undersigned to work together on the ?source-term problem? along with additional Russian experts from the Institute of Plant and Animal Ecology, Ekaterinburg, and the Zababakhin Institute of Technical Physics, Snezhinsk. We are pleased that the study

  9. 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

  10. Dosimetry tools and techniques for IMRT

    SciTech Connect

    Low, Daniel A.; Moran, Jean M.; Dempsey, James F.; Dong Lei; Oldham, Mark

    2011-03-15

    Intensity modulated radiation therapy (IMRT) poses a number of challenges for properly measuring commissioning data and quality assurance (QA) radiation dose distributions. This report provides a comprehensive overview of how dosimeters, phantoms, and dose distribution analysis techniques should be used to support the commissioning and quality assurance requirements of an IMRT program. The proper applications of each dosimeter are described along with the limitations of each system. Point detectors, arrays, film, and electronic portal imagers are discussed with respect to their proper use, along with potential applications of 3D dosimetry. Regardless of the IMRT technique utilized, some situations require the use of multiple detectors for the acquisition of accurate commissioning data. The overall goal of this task group report is to provide a document that aids the physicist in the proper selection and use of the dosimetry tools available for IMRT QA and to provide a resource for physicists that describes dosimetry measurement techniques for purposes of IMRT commissioning and measurement-based characterization or verification of IMRT treatment plans. This report is not intended to provide a comprehensive review of commissioning and QA procedures for IMRT. Instead, this report focuses on the aspects of metrology, particularly the practical aspects of measurements that are unique to IMRT. The metrology of IMRT concerns the application of measurement instruments and their suitability, calibration, and quality control of measurements. Each of the dosimetry measurement tools has limitations that need to be considered when incorporating them into a commissioning process or a comprehensive QA program. For example, routine quality assurance procedures require the use of robust field dosimetry systems. These often exhibit limitations with respect to spatial resolution or energy response and need to themselves be commissioned against more established dosimeters. A chain of

  11. Dosimetry tools and techniques for IMRT.

    PubMed

    Low, Daniel A; Moran, Jean M; Dempsey, James F; Dong, Lei; Oldham, Mark

    2011-03-01

    Intensity modulated radiation therapy (IMRT) poses a number of challenges for properly measuring commissioning data and quality assurance (QA) radiation dose distributions. This report provides a comprehensive overview of how dosimeters, phantoms, and dose distribution analysis techniques should be used to support the commissioning and quality assurance requirements of an IMRT program. The proper applications of each dosimeter are described along with the limitations of each system. Point detectors, arrays, film, and electronic portal imagers are discussed with respect to their proper use, along with potential applications of 3D dosimetry. Regardless of the IMRT technique utilized, some situations require the use of multiple detectors for the acquisition of accurate commissioning data. The overall goal of this task group report is to provide a document that aids the physicist in the proper selection and use of the dosimetry tools available for IMRT QA and to provide a resource for physicists that describes dosimetry measurement techniques for purposes of IMRT commissioning and measurement-based characterization or verification of IMRT treatment plans. This report is not intended to provide a comprehensive review of commissioning and QA procedures for IMRT. Instead, this report focuses on the aspects of metrology, particularly the practical aspects of measurements that are unique to IMRT. The metrology of IMRT concerns the application of measurement instruments and their suitability, calibration, and quality control of measurements. Each of the dosimetry measurement tools has limitations that need to be considered when incorporating them into a commissioning process or a comprehensive QA program. For example, routine quality assurance procedures require the use of robust field dosimetry systems. These often exhibit limitations with respect to spatial resolution or energy response and need to themselves be commissioned against more established dosimeters. A chain of

  12. Dosimetry for animals and plants: contending with biota diversity.

    PubMed

    Ulanovsky, A

    2016-06-01

    Diversity of living organisms and their environmental radiation exposure conditions represents a special challenge for non-human dosimetry. In order to contend with such diversity, the International Commission on Radiological Protection (ICRP) has: (a) set up points of reference by providing dose conversion coefficients (DCCs) for reference entities known as 'Reference Animals and Plants' (RAPs); and (b) used dosimetric models that pragmatically assume simple body shapes with uniform composition and density, homogeneous internal contamination, a limited set of idealised external radiation sources, and truncation of the radioactive decay chains. This pragmatic methodology has been further developed and extended systematically. Significant methodological changes include: a new extended approach for assessing doses of external exposure for terrestrial animals, transition to the contemporary ICRP radionuclide database, assessment-specific consideration of the contribution of radioactive progeny to dose coefficients of parent nuclides, and the use of generalised allometric relationships in the estimation of biokinetic or metabolic parameters. The new methodological developments resulted in a revision of the DCCs for RAPs. Tables of the dose coefficients have now been complemented by a web-based software tool, which can be used to calculate a user-specific DCC for an organism of arbitrary mass and shape, located at user-defined height above the ground, and for an arbitrary radionuclide and its radioactive progeny. PMID:26984904

  13. Nuclear decay data files of the Dosimetry Research Group

    SciTech Connect

    Eckerman, K.F.; Westfall, R.J.; Ryman, J.C.; Cristy, M.

    1993-12-01

    This report documents the nuclear decay data files used by the Dosimetry Research Group at Oak Ridge National Laboratory and the utility DEXRAX which provides access to the files. The files are accessed, by nuclide, to extract information on the intensities and energies of the radiations associated with spontaneous nuclear transformation of the radionuclides. In addition, beta spectral data are available for all beta-emitting nuclides. Two collections of nuclear decay data are discussed. The larger collection contains data for 838 radionuclides, which includes the 825 radionuclides assembled during the preparation of Publications 30 and 38 of the International Commission on Radiological Protection (ICRP) and 13 additional nuclides evaluated in preparing a monograph for the Medical Internal Radiation Dose (MIRD) Committee of the Society of Nuclear Medicine. The second collection is composed of data from the MIRD monograph and contains information for 242 radionuclides. Abridged tabulations of these data have been published by the ICRP in Publication 38 and by the Society of Nuclear Medicine in a monograph entitled ``MIRD: Radionuclide Data and Decay Schemes.`` The beta spectral data reported here have not been published by either organization. Electronic copies of the files and the utility, along with this report, are available from the Radiation Shielding Information Center at Oak Ridge National Laboratory.

  14. Radiation shielding and dosimetry experiments updates in the SINBAD database.

    PubMed

    Kodeli, I; Hunter, H; Sartori, E

    2005-01-01

    The Shielding Integral Benchmark Archive Database (SINBAD) is an internationally established set of radiation shielding and dosimetry data related to experiments relevant in reactor shielding, fusion blanket neutronics and accelerator shielding. In addition to the characterisation of the radiation source, it describes shielding materials and instrumentation and the relevant detectors. The experimental results, be it dose or reaction rates, or unfolded spectra, are presented in tabular ASCII form that can easily be exported to different computer environments for further use. Most sets in SINBAD also contain the computer model used for the interpretation of the experiment and, where available, results from uncertainty analysis. This is an international effort between the Organization for Economic Cooperation and Development, Nuclear Energy Agency Data Bank (http://www.nea.fr/html/databank/) (OECD/NEA Data Bank) and Oak Ridge National Laboratory, Radiation Safety Information Computational Center (http://www-rsicc.ornl.gov/rsic.html) (ORNL/RSICC). Cooperation from many organisations, authors and benchmark analysts have helped SINBAD become a 'living database'--one which involves continuous information updates, preservation and additions of nuclear benchmarks in the areas of fusion, fission and accelerator science and engineering. This paper focuses on the increased comprehensiveness of experiments that have been carried out in recent years and the validation of computer code and cross section library using these experiments. PMID:16604698

  15. Biokinetics and dosimetry of several radiolabelled peptides in cancer cells

    NASA Astrophysics Data System (ADS)

    Rodríguez-Cortés, J.; Ferro-Flores, G.; de Murphy, C. Arteaga; Pedraza-López, M.; Ramírez-Iglesias, M. A. T.

    Radiolabelled peptides have been used as target-specific radiopharmaceuticals. The goal of this research was the in vitro assessment of the uptake, internalization, externalization, and efflux of five radiolabelled peptides in cancer cells to estimate radiation-absorbed doses from experimental biokinetic data. 177Lu-DOTA-octreotate, 188Re-lanreotide, and 99mTc-HYNIC-octreotide were studied in the AR42J cell line. The PC3 and NCIH69 cells were used for 99mTc-HYNIC-bombesin and 177Lu-DOTA-minigastrin, respectively. The cumulated activities in the membrane and cytoplasm were calculated by integration of the experimental time-activity curves and used for dosimetry calculations according to the Medical Internal Radiation Dose (MIRD) cellular methodology. The mean absorbed dose to the cell nucleus were 0.69±0.09, 0.11±0.08, 0.55±0.09, 3.45±0.48, and 3.30±0.65 Gy/Bq for 99mTc-HYNIC-bombesin, 99mTc-HYNIC-octreotide, 177Lu-DOTA-minigastrin, 177Lu-DOTA-octreotate, and 188Re-lanreotide, respectively. If radiopharmaceutical cell kinetics were not used and only uptake data were considered, the calculated doses would be overestimated up to 25 times.

  16. Automatic in vivo portal dosimetry of all treatments

    NASA Astrophysics Data System (ADS)

    Olaciregui-Ruiz, I.; Rozendaal, R.; Mijnheer, B.; van Herk, M.; Mans, A.

    2013-11-01

    At our institution EPID (electronic portal imaging device) dosimetry is routinely applied to perform in vivo dose verification of all patient treatments with curative intent since January 2008. The major impediment of the method has been the amount of work required to produce and inspect the in vivo dosimetry reports (a time-consuming and labor-intensive process). In this paper we present an overview of the actions performed to implement an automated in vivo dosimetry solution clinically. We reimplemented the EPID dosimetry software and modified the acquisition software. Furthermore, we introduced new tools to periodically inspect the record-and-verify database and automatically run the EPID dosimetry software when needed. In 2012, 95% of our 3839 treatments scheduled for in vivo dosimetry were analyzed automatically (27 633 portal images of intensity-modulated radiotherapy (IMRT) fields, 5551 portal image data of VMAT arcs, and 2003 portal images of non-IMRT fields). The in vivo dosimetry verification results are available a few minutes after delivery and alerts are immediately raised when deviations outside tolerance levels are detected. After the clinical introduction of this automated solution, inspection of the detected deviations is the only remaining work. These newly developed tools are a major step forward towards full integration of in vivo EPID dosimetry in radiation oncology practice.

  17. 10 CFR 835.1304 - Nuclear accident dosimetry.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 4 2012-01-01 2012-01-01 false Nuclear accident dosimetry. 835.1304 Section 835.1304 Energy DEPARTMENT OF ENERGY OCCUPATIONAL RADIATION PROTECTION Emergency Exposure Situations § 835.1304 Nuclear accident dosimetry. (a) Installations possessing sufficient quantities of fissile material...

  18. Neutron dosimetry and radiation damage calculations for HFBR

    SciTech Connect

    Greenwood, L.R.; Ratner, R.T.

    1998-03-01

    Neutron dosimetry measurements have been conducted for various positions of the High Flux Beam Reactor (HFBR) at Brookhaven National Laboratory (BNL) in order to measure the neutron flux and energy spectra. Neutron dosimetry results and radiation damage calculations are presented for positions V10, V14, and V15.

  19. 10 CFR 835.1304 - Nuclear accident dosimetry.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 4 2013-01-01 2013-01-01 false Nuclear accident dosimetry. 835.1304 Section 835.1304 Energy DEPARTMENT OF ENERGY OCCUPATIONAL RADIATION PROTECTION Emergency Exposure Situations § 835.1304 Nuclear accident dosimetry. (a) Installations possessing sufficient quantities of fissile material...

  20. 10 CFR 835.1304 - Nuclear accident dosimetry.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 4 2014-01-01 2014-01-01 false Nuclear accident dosimetry. 835.1304 Section 835.1304 Energy DEPARTMENT OF ENERGY OCCUPATIONAL RADIATION PROTECTION Emergency Exposure Situations § 835.1304 Nuclear accident dosimetry. (a) Installations possessing sufficient quantities of fissile material...

  1. Student Perceptions of an Online Medical Dosimetry Program

    ERIC Educational Resources Information Center

    Lenards, Nishele D.

    2007-01-01

    The University of Wisconsin--La Crosse offers the first web-based medical dosimetry program in the nation. There is no data to research a program of this type. This research consisted of the evaluation of other distance education programs including health profession programs in addition to face-to-face medical dosimetry programs. There was need to…

  2. Automatic in vivo portal dosimetry of all treatments.

    PubMed

    Olaciregui-Ruiz, I; Rozendaal, R; Mijnheer, B; van Herk, M; Mans, A

    2013-11-21

    At our institution EPID (electronic portal imaging device) dosimetry is routinely applied to perform in vivo dose verification of all patient treatments with curative intent since January 2008. The major impediment of the method has been the amount of work required to produce and inspect the in vivo dosimetry reports (a time-consuming and labor-intensive process). In this paper we present an overview of the actions performed to implement an automated in vivo dosimetry solution clinically. We reimplemented the EPID dosimetry software and modified the acquisition software. Furthermore, we introduced new tools to periodically inspect the record-and-verify database and automatically run the EPID dosimetry software when needed. In 2012, 95% of our 3839 treatments scheduled for in vivo dosimetry were analyzed automatically (27,633 portal images of intensity-modulated radiotherapy (IMRT) fields, 5551 portal image data of VMAT arcs, and 2003 portal images of non-IMRT fields). The in vivo dosimetry verification results are available a few minutes after delivery and alerts are immediately raised when deviations outside tolerance levels are detected. After the clinical introduction of this automated solution, inspection of the detected deviations is the only remaining work. These newly developed tools are a major step forward towards full integration of in vivo EPID dosimetry in radiation oncology practice. PMID:24201085

  3. Retrospective assessment of personnel neutron dosimetry for workers at the Hanford Site

    SciTech Connect

    Fix, J.J.; Wilson, R.H.; Baumgartner, W.B.

    1996-09-01

    This report was prepared to examine the specific issue of the potential for unrecorded neutron dose for Hanford workers, particularly in comparison with the recorded whole body (neutron plus photon) dose. During the past several years, historical personnel dosimetry practices at Hanford have been documented in several technical reports. This documentation provides a detailed history of the technology, radiation fields, and administrative practices used to measure and record dose for Hanford workers. Importantly, documentation has been prepared by personnel whose collective experience spans nearly the entire history of Hanford operations beginning in the mid-1940s. Evaluations of selected Hanford radiation dose records have been conducted along with statistical profiles of the recorded dose data. The history of Hanford personnel dosimetry is complex, spanning substantial evolution in radiation protection technology, concepts, and standards. Epidemiologic assessments of Hanford worker mortality and radiation dose data were initiated in the early 1960s. In recent years, Hanford data have been included in combined analyses of worker cohorts from several Department of Energy (DOE) sites and from several countries through the International Agency for Research on Cancer (IARC). Hanford data have also been included in the DOE Comprehensive Epidemiologic Data Resource (CEDR). In the analysis of Hanford, and other site data, the question of comparability of recorded dose through time and across the respective sites has arisen. DOE formed a dosimetry working group composed of dosimetrists and epidemiologists to evaluate data and documentation requirements of CEDR. This working group included in its recommendations the high priority for documentation of site-specific radiation dosimetry practices used to measure and record worker dose by the respective DOE sites.

  4. EURADOS strategic research agenda: vision for dosimetry of ionising radiation.

    PubMed

    Rühm, W; Fantuzzi, E; Harrison, R; Schuhmacher, H; Vanhavere, F; Alves, J; Bottollier Depois, J F; Fattibene, P; Knežević, Ž; Lopez, M A; Mayer, S; Miljanić, S; Neumaier, S; Olko, P; Stadtmann, H; Tanner, R; Woda, C

    2016-02-01

    Since autumn 2012, the European Radiation Dosimetry Group (EURADOS) has been developing its Strategic Research Agenda (SRA), which is intended to contribute to the identification of future research needs in radiation dosimetry in Europe. The present article summarises-based on input from EURADOS Working Groups (WGs) and Voting Members-five visions in dosimetry and defines key issues in dosimetry research that are considered important for the next decades. The five visions include scientific developments required towards (a) updated fundamental dose concepts and quantities, (b) improved radiation risk estimates deduced from epidemiological cohorts, (c) efficient dose assessment for radiological emergencies, (d) integrated personalised dosimetry in medical applications and (e) improved radiation protection of workers and the public. The SRA of EURADOS will be used as a guideline for future activities of the EURADOS WGs. A detailed version of the SRA can be downloaded as a EURADOS report from the EURADOS website (www.eurados.org). PMID:25752758

  5. Developments in Neutron Spectrometry and Dosimetry in Support of the U.K. Naval Nuclear Propulsion Program

    SciTech Connect

    P. A. Beeley; N. M. Spyrou; J. M. Brushwood; A. M. Williams

    2000-11-12

    The Defence Radiological Protection Service (DRPS) is tasked with providing the approved dosimetry service to the Naval Nuclear Propulsion Program (NNPP). Within this requirement, DRPS operates a track-etch system for whole-body neutron dosimetry, using the well-known material polyally dyglycol carbonate as the sensitive element. These dosimeters have a number of limitations, including a high limit of detection (typically 200 microsieverts), insensitivity to low-energy neutrons, and a strong angular dependence. Such limitations, along with the incorporation of the recommendations of the International Commission on Radiological Protection (ICRP) 60 into the revised U.K. Ionizing Radiation Regulations 1999, have provided the opportunity to reconsider spectrometric and dosimetric research in support of the NNPP. Area neutron dosimetry is most usually performed using a Leake-type spherical survey meter. In both the case of area and, more significantly, personal dosimetry, the differences in the energy spectra between the calibration and the operational fields require a location correction factor (LCF) to be applied. To determine these LCFs, it is necessary to accurately characterize the operational energy spectra. This characterization is undertaken using the transportable neutron spectrometer (TNS) developed by the U.K. Atomic Energy Establishment at Winfrith in the 1980s. Our research has focused on two areas, the development of an improved TNS system and a complimentary program to design a new area survey meter.

  6. High-energy neutron dosimetry

    NASA Astrophysics Data System (ADS)

    Sutton, Michele Rhea

    2001-12-01

    Fluence-to-dose conversion coefficients for the radiation protection quantity effective dose were calculated for neutrons, photons and protons with energies up to 2 GeV using the MCNPX code. The calculations were performed using the Pacific Northwest National Laboratory versions of the MIRD-V male and female anthropomorphic phantoms modified to include the skin and esophagus. The latest high-energy neutron evaluated cross-section libraries and the recommendations given in ICRP Publication 60 and ICRP Publication 74 were utilized to perform the calculations. Sets of fluence-to- effective dose conversion coefficients are given for anterior-posterior, posterior-anterior, left-lateral, right-lateral and rotational irradiation geometries. This is the first set of dose conversion coefficients over this energy range calculated for the L-LAT irradiation geometry. A unique set of high-energy neutron depth-dose benchmark experiments were performed at the Los Alamos Neutron Science Center/Weapons Neutron Research (LANSCE/WNR) complex. The experiments consisted of filtered neutron beams with energies up to 800 MeV impinging on a 30 x 30 x 30 cm3 tissue-equivalent phantom. The absorbed dose was measured in the phantom at various depths with tissue-equivalent ion chambers. The phantom and the experimental set-up were modeled using MCNPX. Comparisons of the experimental and computational depth- dose distributions indicate that the absorbed dose calculated by MCNPX is within 13% for neutrons with energies up to 750 MeV. This experiment will serve as a benchmark experiment for the testing of high-energy radiation transport codes for the international radiation protection community.

  7. Improving neutron dosimetry using bubble detector technology

    SciTech Connect

    Buckner, M.A.

    1993-02-01

    Providing accurate neutron dosimetry for a variety of neutron energy spectra is a formidable task for any dosimetry system. Unless something is known about the neutron spectrum prior to processing the dosimeter, the calculated dose may vary greatly from that actually encountered; that is until now. The entrance of bubble detector technology into the field of neutron dosimetry has eliminated the necessity of having an a priori knowledge of the neutron energy spectra. Recently, a new approach in measuring personnel neutron dose equivalent was developed at Oak Ridge National Laboratory. By using bubble detectors in combination with current thermoluminescent dosimeters (TLDs) as a Combination Personnel Neutron Dosimeter (CPND), not only is it possible to provide accurate dose equivalent results, but a simple four-interval neutron energy spectrum is obtained as well. The components of the CPND are a Harshaw albedo TLD and two bubble detectors with theoretical energy thresholds of 100 key and 1500 keV. Presented are (1) a synoptic history surrounding emergence of bubble detector technology, (2) a brief overview of the current theory on mechanisms of interaction, (3) the data and analysis process involved in refining the response functions, (4) performance evaluation of the original CPND and a reevaluation of the same data under the modified method, (5) the procedure used to determine the reference values of component fluence and dose equivalent for field assessment, (6) analysis of the after-modification results, (7) a critique of some currently held assumptions, offering some alternative explanations, and (8) thoughts concerning potential applications and directions for future research.

  8. In vivo light dosimetry for pleural PDT

    NASA Astrophysics Data System (ADS)

    Dimofte, Andreea; Zhu, Timothy C.; Finlay, Jarod C.; Culligan, Melissa; Edmonds, Christine E.; Friedberg, Joseph S.; Cengel, Keith; Hahn, Stephen M.

    2009-02-01

    In-vivo light Dosimetry for patients undergoing photodynamic therapy (PDT) is one of the important dosimetry quantities critical for predicting PDT outcome. This study examines the light fluence (rate) delivered to patients undergoing pleural PDT as a function of treatment time, treatment volume and surface area, and its accuracy as a function of the calibration accuracies of each isotropic detector and the calibration integrating sphere. The patients studied here were enrolled in Phase II clinical trial of Photofrin-mediated PDT for the treatment of non-small cell lung cancer with pleural effusion. The ages of the patients studied varied from 34 to 69 year old. All patients were administered 2mg per kg body weight Photoprin 24 hours before the surgery. Patients undergoing photodynamic therapy (PDT) are treated with laser light with a light fluence of 60 J/cm^2 at 630nm. Fluence rate (mW/cm^2) and cumulative fluence (J/cm^2) was monitored at 7 different sites during the entire light treatment delivery. Isotropic detectors were used for in-vivo light dosimetry. The anisotropy of each isotropic detector was found to be within 30%. The mean fluence rate delivery varied from 37.84 to 94.05 mW/cm^2 and treatment time varied from 1762 to 5232s. We have established a correlation between the treatment time and the treatment volume. The results are discussed using an integrating sphere theory and the measured tissue optical properties. The result can be used as a clinical guideline for future pleural PDT treatment.

  9. Model selection for radiochromic film dosimetry

    NASA Astrophysics Data System (ADS)

    Méndez, I.

    2015-05-01

    The purpose of this study was to find the most accurate model for radiochromic film dosimetry by comparing different channel independent perturbation models. A model selection approach based on (algorithmic) information theory was followed, and the results were validated using gamma-index analysis on a set of benchmark test cases. Several questions were addressed: (a) whether incorporating the information of the non-irradiated film, by scanning prior to irradiation, improves the results; (b) whether lateral corrections are necessary when using multichannel models; (c) whether multichannel dosimetry produces better results than single-channel dosimetry; (d) which multichannel perturbation model provides more accurate film doses. It was found that scanning prior to irradiation and applying lateral corrections improved the accuracy of the results. For some perturbation models, increasing the number of color channels did not result in more accurate film doses. Employing Truncated Normal perturbations was found to provide better results than using Micke-Mayer perturbation models. Among the models being compared, the triple-channel model with Truncated Normal perturbations, net optical density as the response and subject to the application of lateral corrections was found to be the most accurate model. The scope of this study was circumscribed by the limits under which the models were tested. In this study, the films were irradiated with megavoltage radiotherapy beams, with doses from about 20-600 cGy, entire (8 inch  × 10 inch) films were scanned, the functional form of the sensitometric curves was a polynomial and the different lots were calibrated using the plane-based method.

  10. Multisegmented ion chamber for CT scanner dosimetry

    SciTech Connect

    Moore, M.M.; Cacak, R.K.; Hendee, W.R.

    1981-01-01

    A multisegmented, ionization chamber capable of determining dosimetric profiles from a CT scanner has been developed and tested. The chamber consists of a number of 2 mm wide electrically isolated segments from which ionization currents may be measured. Presented here are the performance characteristics of the chamber including energy response, dose linearity, and corrections for ''cross talk'' between segments. Sample dosimetric profiles are depicted for 3 and 6 mm nominal beam widths at two locations in a dosimetric phantom positioned in the x-ray beam of a fourth generation CT scanner. The results agree well with the conventional method of obtaining dosimetry measurements with TLD chips.

  11. Neutron dosimetry of the Little Boy device

    SciTech Connect

    Pederson, R.A.; Plassmann, E.A.

    1984-01-01

    Neutron dose rates at several angular locations and at distances out to 0.5 mile have been measured during critical operation of the Little Boy replica. We used modified remmetes and thermoluminescent dosimetry techniques for the measurements. The present status of our analysis is presented including estimates of the neutron-dose-relaxation length in air and the variation of the neutron-to-gamma-ray dose ratio with distance from the replica. These results are preliminary and are subject to detector calibration measurements.

  12. Proton minibeam radiation therapy: Experimental dosimetry evaluation

    SciTech Connect

    Peucelle, C.; Martínez-Rovira, I.; Prezado, Y.; Nauraye, C.; Patriarca, A.; Hierso, E.; Fournier-Bidoz, N.

    2015-12-15

    Purpose: Proton minibeam radiation therapy (pMBRT) is a new radiotherapy (RT) approach that allies the inherent physical advantages of protons with the normal tissue preservation observed when irradiated with submillimetric spatially fractionated beams. This dosimetry work aims at demonstrating the feasibility of the technical implementation of pMBRT. This has been performed at the Institut Curie - Proton Therapy Center in Orsay. Methods: Proton minibeams (400 and 700 μm-width) were generated by means of a brass multislit collimator. Center-to-center distances between consecutive beams of 3200 and 3500 μm, respectively, were employed. The (passive scattered) beam energy was 100 MeV corresponding to a range of 7.7 cm water equivalent. Absolute dosimetry was performed with a thimble ionization chamber (IBA CC13) in a water tank. Relative dosimetry was carried out irradiating radiochromic films interspersed in a IBA RW3 slab phantom. Depth dose curves and lateral profiles at different depths were evaluated. Peak-to-valley dose ratios (PVDR), beam widths, and output factors were also assessed as a function of depth. Results: A pattern of peaks and valleys was maintained in the transverse direction with PVDR values decreasing as a function of depth until 6.7 cm. From that depth, the transverse dose profiles became homogeneous due to multiple Coulomb scattering. Peak-to-valley dose ratio values extended from 8.2 ± 0.5 at the phantom surface to 1.08 ± 0.06 at the Bragg peak. This was the first time that dosimetry in such small proton field sizes was performed. Despite the challenge, a complete set of dosimetric data needed to guide the first biological experiments was achieved. Conclusions: pMBRT is a novel strategy in order to reduce the side effects of RT. This works provides the experimental proof of concept of this new RT method: clinical proton beams might allow depositing a (high) uniform dose in a brain tumor located in the center of the brain (7.5 cm depth

  13. The next decade in external dosimetry

    SciTech Connect

    Griffith, R.V.

    1986-10-01

    As the radiation protection community moves through the last half of the '80s and into the next decade, we can expect the requirements for external dosimetry to become increasingly more restrictive and demanding. As in other health protection fields, growing regulatory and legal pressures, together with a natural evolution in philosophy, require the health physicist to display an increasing degree of accountability, rigor, and professionalism. The good news is that, for the most part, the technology necessary to solve many of the problems will be available or not far behind. This paper describes anticipated technology. 66 refs., 10 figs.

  14. Hydroxyanthraquinone dye solutions for radiation dosimetry.

    PubMed

    Bedear El-Assy, N; Alian, A; Abdel Rahim, F; Roushdy, H

    1982-06-01

    An investigation has been carried out on the effect of gamma-radiation on the absorption spectra of aqueous solutions of the hydroxyanthraquinone dyes, alizarin and alizarin red S. Ionizing radiation at absorbed doses over the range 10(5)-3 x 10(6) rad brought about gradual bleaching of aerated (oxygenated) dye solutions. The radiolytic bleaching was enhanced through addition of hydrogen peroxide, as expected. A mechanism for the radiolytic reaction is proposed, based on chemical attack of the chromophore by radicals and radical ions as aqueous radiolysis products. Suggestions are made for possible radiation dosimetry by means of spectrophotometric analysis of the absorption spectra. PMID:7107037

  15. Personal dosimetry for human missions to Mars based on TLD and LET-spectrometry technique.

    PubMed

    Apathy, I; Beaujean, R; Deme, S; Pazmandi, T; Reitz, G

    2003-01-01

    Exposure of crew to the space radiation environment poses one of the most significant problems in long term missions in low earth orbits and in interplanetary missions. Accurate personal dose measurement will become increasingly important especially during manned missions to Mars. A series of instruments suitable for on-board dose, flux and LET measurements has been developed by the authors'. Based on the experience gained so far from their utilization, an instrument consisting of a thermoluminescent device and a dosimetry telescope is proposed for the use on the International Space Station and for human Mars missions. The short technical description of this instrument is given in this paper. PMID:12577920

  16. Radon source apportionment in the home, dosimetry and risk modeling. Final report, 1993--1997

    SciTech Connect

    Harley, N.H.

    1998-08-04

    This research covered the following 3 topics in 4 years: (1) the source apportionment of {sup 222}Rn in the home; (2) the internal bronchial dosimetry of inhaled {sup 222}Rn decay products; and (3) the lung cancer risk from inhalation of the short lived decay products of {sup 222}Rn. A 4th year of support was appended to this grant with a switch in research effort to determine a method for long term measurement of the particle size distribution of the short lived decay products in homes.

  17. Personal dosimetry for human missions to Mars based on TLD and LET-spectrometry technique

    NASA Astrophysics Data System (ADS)

    Apáthy, I.; Beaujean, R.; Deme, S.; Pázmándi, T.; Reitz, G.

    Exposure of crew to the space radiation environment poses one of the most significant problems in long term missions in low earth orbits and in interplanetary missions. Accurate personal dose measurement will become increasingly important especially during manned missions to Mars. A series of instruments suitable for on-board dose, flux and LET measurements has been developed by the authors'. Based on the experience gained so far from their utilization, an instrument consisting of a thermoluminescent device and a dosimetry telescope is proposed for the use on the International Space Station and for human Mars missions. The short technical description of this instrument is given in this paper.

  18. Effect of processor temperature on film dosimetry

    SciTech Connect

    Srivastava, Shiv P.; Das, Indra J.

    2012-07-01

    Optical density (OD) of a radiographic film plays an important role in radiation dosimetry, which depends on various parameters, including beam energy, depth, field size, film batch, dose, dose rate, air film interface, postexposure processing time, and temperature of the processor. Most of these parameters have been studied for Kodak XV and extended dose range (EDR) films used in radiation oncology. There is very limited information on processor temperature, which is investigated in this study. Multiple XV and EDR films were exposed in the reference condition (d{sub max.}, 10 Multiplication-Sign 10 cm{sup 2}, 100 cm) to a given dose. An automatic film processor (X-Omat 5000) was used for processing films. The temperature of the processor was adjusted manually with increasing temperature. At each temperature, a set of films was processed to evaluate OD at a given dose. For both films, OD is a linear function of processor temperature in the range of 29.4-40.6 Degree-Sign C (85-105 Degree-Sign F) for various dose ranges. The changes in processor temperature are directly related to the dose by a quadratic function. A simple linear equation is provided for the changes in OD vs. processor temperature, which could be used for correcting dose in radiation dosimetry when film is used.

  19. Investigation of the dosimetry of chest tomosynthesis

    NASA Astrophysics Data System (ADS)

    Svalkvist, Angelica; Zachrisson, Sara; Månsson, Lars Gunnar; Båth, Magnus

    2009-02-01

    Chest tomosynthesis has recently been introduced to healthcare as a low-dose alternative to CT or as a tool for improved diagnostics in chest radiography with only a modest increase in radiation dose to the patient. However, no detailed description of the dosimetry for this type of examination has been presented. The aim of this work was therefore to investigate the dosimetry of chest tomosynthesis. The chest tomosynthesis examination was assumed to be performed using a stationary detector and a vertically moving x-ray tube, exposing the patient from different angles. The Monte Carlo based computer software PCXMC was used to determine the effective dose delivered to a standard-sized patient from various angles using different assumptions of the distribution of the effective dose over the different projections. The obtained conversion factors between input dose measures and effective dose for chest tomosynthesis for different angular intervals were then compared with the horizontal projection. The results indicate that the error introduced by using conversion factors for the PA projection in chest radiography for estimating the effective dose of chest tomosynthesis is small for normally sized patients, especially if a conversion factor between KAP and effective dose is used.

  20. Numerical dosimetry dedicated to children RF exposure.

    PubMed

    Wiart, Joe; Hadjem, Abdelhamid; Varsier, Nadège; Conil, Emmanuelle

    2011-12-01

    Children are more and more using wireless communication systems. This growth has strengthened public concern and has highlighted the need to assess the radio frequency (RF) exposure of children. In dosimetry, taking advantage of the improvement of High Performance Calculation systems, great efforts have been carried out to improve the numerical tools and human models used to assess the Specific Absorption Rate (SAR). This paper analyses progress in building child and foetus models for numerical dosimetry purpose. The simulation results, in terms of Specific Absorption Rate over 1 and 10 g of tissues, in specific organs such as brain and averaged over the whole body, are reported and analysed. The results show that compliance methods used nowadays to certify phones are valid for children. The studies also show that specific tissues such as peripheral brain tissues can have higher exposure with children than with adults. Studies performed with plane waves as sources and whole body children models show that the whole body SAR of children can be higher than the WBSAR of adults and that the compliance to ICNIRP reference levels does not guarantee the compliance to ICNIRP basic restrictions. Dealing with the foetus models and dielectric properties great efforts have been made. Preliminary results show that the foetus exposure is often lower than the mother exposure, with an important influencing parameter: the foetus position in the uterus. PMID:22005525

  1. Dosimetry of inhaled radon and thoron progeny

    SciTech Connect

    James, A.C.

    1994-06-01

    This chapter reviews recent developments in modeling doses received by lung tissues, with particular emphasis on application of ICRP`s new dosimetric model of the respiratory tract for extrapolating to other environments the established risks from exposure to radon progeny in underground mines. Factors discussed include: (1) the influence of physical characteristics of radon progeny aerosols on dose per unit exposure, e.g., the unattached fraction, and the activity-size distributions of clustered and attached progeny; (2) the dependence of dose on breathing rate, and on the exposed subject (man, woman or child); (3) the variability of dose per unit exposure in a home when exposure is expressed in terms of potential {alpha} energy or radon gas concentration; (4) the comparative dosimetry of thoron progeny; and (5) the effects of air-cleaning on lung dose. Also discussed is the apparent discrepancy between lung cancer risk estimates derived purely from dosimetry and the lung cancer incidence observed in the epidemiological studies of radon-exposed underground miners. Application of ICRP`s recommended risk factors appears to overestimate radon lung-cancer risk for miners by a factor of three. ``Normalization`` of the calculated effective dose is therefore needed, at least for {alpha} dose from radon and thoron progeny, in order to obtain a realistic estimate of lung cancer risk.

  2. Eleventh DOE workshop on personnel neutron dosimetry

    SciTech Connect

    Not Available

    1991-12-31

    Since its formation, the Office of Health (EH-40) has stressed the importance of the exchange of information related to and improvements in neutron dosimetry. This Workshop was the eleventh in the series sponsored by the Department of Energy (DOE). It provided a forum for operational personnel at DOE facilities to discuss current issues related to neutron dosimetry and for leading investigators in the field to discuss promising approaches for future research. A total of 26 papers were presented including the keynote address by Dr. Warren K. Sinclair, who spoke on, ``The 1990 Recommendations of the ICRP and their Biological Background.`` The first several papers discussed difficulties in measuring neutrons of different energies and ways of compensating or deriving correction factors at individual facilities. Presentations were also given by the US Navy and Air Force. Current research in neutron dosimeter development was the subject of the largest number of papers. These included a number on the development of neutron spectrometers. Selected papers were processed separately for inclusion in the Energy Science and Technology Database.

  3. The importance of 3D dosimetry

    NASA Astrophysics Data System (ADS)

    Low, Daniel

    2015-01-01

    Radiation therapy has been getting progressively more complex for the past 20 years. Early radiation therapy techniques needed only basic dosimetry equipment; motorized water phantoms, ionization chambers, and basic radiographic film techniques. As intensity modulated radiation therapy and image guided therapy came into widespread practice, medical physicists were challenged with developing effective and efficient dose measurement techniques. The complex 3-dimensional (3D) nature of the dose distributions that were being delivered demanded the development of more quantitative and more thorough methods for dose measurement. The quality assurance vendors developed a wide array of multidetector arrays that have been enormously useful for measuring and characterizing dose distributions, and these have been made especially useful with the advent of 3D dose calculation systems based on the array measurements, as well as measurements made using film and portal imagers. Other vendors have been providing 3D calculations based on data from the linear accelerator or the record and verify system, providing thorough evaluation of the dose but lacking quality assurance (QA) of the dose delivery process, including machine calibration. The current state of 3D dosimetry is one of a state of flux. The vendors and professional associations are trying to determine the optimal balance between thorough QA, labor efficiency, and quantitation. This balance will take some time to reach, but a necessary component will be the 3D measurement and independent calculation of delivered radiation therapy dose distributions.

  4. PDT dose dosimetry for pleural photodynamic therapy

    NASA Astrophysics Data System (ADS)

    Sharikova, Anna V.; Finlay, Jarod C.; Liang, Xing; Zhu, Timothy C.

    2013-03-01

    PDT dose is the product of the photosensitizer concentration and the light fluence in target tissue. Although existing systems are capable of measuring the light fluence in vivo, the concurrent measurement of photosensitizer in the treated tissue so far has been lacking. We have developed and tested a new method to simultaneously acquire light dosimetry and photosensitizer fluorescence data via the same isotropic detector, employing treatment light as the excitation source. A dichroic beamsplitter is used to split light from the isotropic detector into two fibers, one for light dosimetry, the other, after the 665 nm treatment light is removed by a band-stop filter, to a spectrometer for fluorescence detection. The light fluence varies significantly during treatment because of the source movement. The fluorescence signal is normalized by the light fluence measured at treatment wavelength. We have shown that the absolute photosensitizer concentration can be obtained by an optical properties correction factor and linear spectral fitting. Tissue optical properties are determined using an absorption spectroscopy probe immediately before PDT at the same sites. This novel method allows accurate real-time determination of delivered PDT dose using existing isotropic detectors, and may lead to a considerable improvement of PDT treatment quality compared to the currently employed systems. Preliminary data in patient studies is presented.

  5. An absorbed dose calorimeter for IMRT dosimetry

    NASA Astrophysics Data System (ADS)

    Duane, S.; Aldehaybes, M.; Bailey, M.; Lee, N. D.; Thomas, C. G.; Palmans, H.

    2012-10-01

    A new calorimeter for dosimetry in small and complex fields has been built. The device is intended for the direct determination of absorbed dose to water in moderately small fields and in composite fields such as IMRT treatments, and as a transfer instrument calibrated against existing absorbed dose standards in conventional reference conditions. The geometry, materials and mode of operation have been chosen to minimize detector perturbations when used in a water phantom, to give a reasonably isotropic response and to minimize the effects of heat transfer when the calorimeter is used in non-reference conditions in a water phantom. The size of the core is meant to meet the needs of measurement in IMRT treatments and is comparable to the size of the air cavity in a type NE2611 ionization chamber. The calorimeter may also be used for small field dosimetry. Initial measurements in reference conditions and in an IMRT head and neck plan, collapsed to gantry angle zero, have been made to estimate the thermal characteristics of the device, and to assess its performance in use. The standard deviation (estimated repeatability) of the reference absorbed dose measurements was 0.02 Gy (0.6%).

  6. Dosimetry of radium-223 and progeny

    SciTech Connect

    Fisher, D.R.; Sgouros, G.

    1999-01-01

    Radium-223 is a short-lived (11.4 d) alpha emitter with potential applications in radioimmunotherapy of cancer. Radium-223 can be complexed and linked to protein delivery molecules for specific tumor-cell targeting. It decays through a cascade of short-lived alpha- and beta-emitting daughters with emission of about 28 MeV of energy through complete decay. The first three alpha particles are essentially instantaneous. Photons associated with Ra-223 and progeny provide the means for tumor and normal-organ imaging and dosimetry. Two beta particles provide additional therapeutic value. Radium-223 may be produced economically and in sufficient amounts for widescale application. Many aspects of the chemistry of carrier-free isotope preparation, complexation, and linkage to the antibody have been developed and are being tested. The radiation dosimetry of a Ra-223-labeled antibody shows favorable tumor to normal tissue dose ratios for therapy. The 11.4-d half-life of Ra-223 allows sufficient time for immunoconjugate preparation, administration, and tumor localization by carrier antibodies before significant radiological decay takes place. If 0.01 percent of a 37 MBq (1 mCi) injection deposits in a one gram tumor mass, and if the activity is retained with a typical effective half-time (75 h), the absorbed dose will be 163 mGy MBq{sup {minus}1} (600 rad mCi{sup {minus}1}) administered. 49 refs., 5 figs., 2 tabs.

  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. Dosimetry of ionising radiation in modern radiation oncology

    NASA Astrophysics Data System (ADS)

    Kron, Tomas; Lehmann, Joerg; Greer, Peter B.

    2016-07-01

    Dosimetry of ionising radiation is a well-established and mature branch of physical sciences with many applications in medicine and biology. In particular radiotherapy relies on dosimetry for optimisation of cancer treatment and avoidance of severe toxicity for patients. Several novel developments in radiotherapy have introduced new challenges for dosimetry with small and dynamically changing radiation fields being central to many of these applications such as stereotactic ablative body radiotherapy and intensity modulated radiation therapy. There is also an increasing awareness of low doses given to structures not in the target region and the associated risk of secondary cancer induction. Here accurate dosimetry is important not only for treatment optimisation but also for the generation of data that can inform radiation protection approaches in the future. The article introduces some of the challenges and highlights the interdependence of dosimetric calculations and measurements. Dosimetric concepts are explored in the context of six application fields: reference dosimetry, small fields, low dose out of field, in vivo dosimetry, brachytherapy and auditing of radiotherapy practice. Recent developments of dosimeters that can be used for these purposes are discussed using spatial resolution and number of dimensions for measurement as sorting criteria. While dosimetry is ever evolving to address the needs of advancing applications of radiation in medicine two fundamental issues remain: the accuracy of the measurement from a scientific perspective and the importance to link the measurement to a clinically relevant question. This review aims to provide an update on both of these.

  9. Dosimetry of ionising radiation in modern radiation oncology.

    PubMed

    Kron, Tomas; Lehmann, Joerg; Greer, Peter B

    2016-07-21

    Dosimetry of ionising radiation is a well-established and mature branch of physical sciences with many applications in medicine and biology. In particular radiotherapy relies on dosimetry for optimisation of cancer treatment and avoidance of severe toxicity for patients. Several novel developments in radiotherapy have introduced new challenges for dosimetry with small and dynamically changing radiation fields being central to many of these applications such as stereotactic ablative body radiotherapy and intensity modulated radiation therapy. There is also an increasing awareness of low doses given to structures not in the target region and the associated risk of secondary cancer induction. Here accurate dosimetry is important not only for treatment optimisation but also for the generation of data that can inform radiation protection approaches in the future. The article introduces some of the challenges and highlights the interdependence of dosimetric calculations and measurements. Dosimetric concepts are explored in the context of six application fields: reference dosimetry, small fields, low dose out of field, in vivo dosimetry, brachytherapy and auditing of radiotherapy practice. Recent developments of dosimeters that can be used for these purposes are discussed using spatial resolution and number of dimensions for measurement as sorting criteria. While dosimetry is ever evolving to address the needs of advancing applications of radiation in medicine two fundamental issues remain: the accuracy of the measurement from a scientific perspective and the importance to link the measurement to a clinically relevant question. This review aims to provide an update on both of these. PMID:27351409

  10. Upgraded Neutron Dosimetry Procedure for VVER-440 Surveilance Specimens

    NASA Astrophysics Data System (ADS)

    Kochkin, V.; Erak, D.; Zaritsky, S.; Egorov, A.; Makhotin, D.

    2009-08-01

    The control of Reactor Pressure Vessel (RPV) metal during lifetime is one of the basic conditions of the reliable and safe operation of a reactor and NPP as a whole. The substantiation of safe RPV operation is based on Surveillance Specimens (SS) testing results and their transfer to the RPV. Since the reliability of the SS program directly depends on the dosimetry accuracy, one of the most important tasks in the investigation of SS is precision estimation of fast neutron fluence (E > 0.5MeV) for each specimen. The upgraded procedure of neutron fluence evaluation for surveillance specimens of VVER-440/213 reactor has been developed and is presented in this paper. This procedure based on measurements of the 54Mn activity of each of the surveillance specimens and neutron field computations. In contrast to the earlier procedures the new one takes into account correctly all pressure vessel internals, influence of core pattern on the neutron field in SS channel, and dependence of spectral index SI0.5/3.0 on the axial coordinate of surveillance specimens. The upgraded procedure is used for neutron fluence evaluation of VVER-440 surveillance and research programs in RRC "Kurchatov institute".

  11. Magnetic Particle Detection (MPD) for In-Vitro Dosimetry

    SciTech Connect

    Minard, Kevin R.; Littke, Matthew H.; Wang, Wei; Xiong, Yijia; Teeguarden, Justin G.; Thrall, Brian D.

    2013-05-15

    In-vitro tests intended for evaluating the potential health effects of magnetic nanoparticles generally require an accurate measure of cell dose to promote the consistent use and interpretation of biological response. Here, a simple low-cost inductive sensor is developed for quickly determining the total mass of magnetic nanoparticles that is bound to the plasma membrane and internalized by cultured cells. Sensor operation exploits an oscillating magnetic field (f0 = 250 kHz) together with the nonlinear response of particle magnetization to generate a harmonic signal (f3 = 750 kHz) that varies linearly with particulate mass (R2 > 0.999) and is sufficiently sensitive for detecting ~ 100 ng of carboxyl-coated iron-oxide nanoparticles in under a second. When exploited for measuring receptor-mediated nanoparticle uptake in RAW 264.7 macrophages, results show that achieved dosimetry performance is comparable with relatively expensive analytical techniques that are much more time-consuming and labor-intensive to perform. Described sensing is therefore potentially better suited for low-cost in-vitro assays that require fast and quantitative magnetic particle detection.

  12. SILICON PHOTOMULTIPLIERS FOR MEDICAL IMAGING AND DOSIMETRY-AN OVERVIEW.

    PubMed

    Herrnsdorf, L; Caccia, M; Mattsson, S

    2016-06-01

    Silicon photomultipliers (SiPMs) are an enabling solid-state technology for low light sensing, with single photon sensitivity and photon number resolving capability. They feature an extremely high internal gain at the 10(6) level, comparable to photomultiplier tubes (PMTs), with the advantage of low operating voltage (~50 V compared to ~1000 V for PMT) and low energy consumption. The solid-state technology makes SiPMs compact, insensitive to magnetic fields and with an extreme flexibility in the design to cope with different applications. The fast development of the multiplication avalanche opens up the possibility to achieve time resolution at the 30 ps level. Dynamic range is however limited compared to PMT and the dark count rate relatively high, yet today at the level of 50 kHz/mm(2) at room temperature. Interfaced with scintillation material, SiPMs provide a powerful platform for medical imaging applications (in positron emission tomography/computed tomography and in positron emission tomography/magnetic resonance), for X-ray quality control as well as for novel compact radiation protection instruments. This article gives an overview of SiPMs for medical imaging and dosimetry. In addition, a learning and training program targeted to graduate students is described. PMID:27103639

  13. 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.

  14. Patient-Specific Dosimetry and Radiobiological Modeling of Targeted Radionuclide Therapy Grant - final report

    SciTech Connect

    George Sgouros, Ph.D.

    2007-03-20

    The broad, long-term objectives of this application are to 1. develop easily implementable tools for radionuclide dosimetry that can be used to predict normal organ toxicity and tumor response in targeted radionuclide therapy; and 2. to apply these tools to the analysis of clinical trial data in order to demonstrate dose-response relationships for radionuclide therapy treatment planning. The work is founded on the hypothesis that robust dose-response relationships have not been observed in targeted radionuclide therapy studies because currently available internal dosimetry methodologies are inadequate, failing to adequately account for individual variations in patient anatomy, radionuclide activity distribution/kinetics, absorbed dose-distribution, and absorbed dose-rate. To reduce development time the previously available software package, 3D-ID, one of the first dosimetry software packages to incorporate 3-D radionuclide distribution with individual patient anatomy; and the first to be applied for the comprehensive analysis of patient data, will be used as a platform to build the functionality listed above. The following specific aims are proposed to satisfy the long-term objectives stated above: 1. develop a comprehensive and validated methodology for converting one or more SPECT images of the radionuclide distribution to a 3-D representation of the cumulated activity distribution; 2. account for differences in tissue density and atomic number by incorporating an easily implementable Monte Carlo methodology for the 3-D dosimetry calculations; 3. incorporate the biologically equivalent dose (BED) and equivalent uniform dose (EUD) models to convert the spatial distribution of absorbed dose and dose-rate into equivalent single values that account for differences in dose uniformity and rate and that may be correlated with tumor response and normal organ toxicity; 4. test the hypothesis stated above by applying the resulting package to patient trials of targeted

  15. A nephron-based model of the kidneys for macro-to-micro α-particle dosimetry

    NASA Astrophysics Data System (ADS)

    Hobbs, Robert F.; Song, Hong; Huso, David L.; Sundel, Margaret H.; Sgouros, George

    2012-07-01

    Targeted α-particle therapy is a promising treatment modality for cancer. Due to the short path-length of α-particles, the potential efficacy and toxicity of these agents is best evaluated by microscale dosimetry calculations instead of whole-organ, absorbed fraction-based dosimetry. Yet time-integrated activity (TIA), the necessary input for dosimetry, can still only be quantified reliably at the organ or macroscopic level. We describe a nephron- and cellular-based kidney dosimetry model for α-particle radiopharmaceutical therapy, more suited to the short range and high linear energy transfer of α-particle emitters, which takes as input kidney or cortex TIA and through a macro to micro model-based methodology assigns TIA to micro-level kidney substructures. We apply a geometrical model to provide nephron-level S-values for a range of isotopes allowing for pre-clinical and clinical applications according to the medical internal radiation dosimetry (MIRD) schema. We assume that the relationship between whole-organ TIA and TIA apportioned to microscale substructures as measured in an appropriate pre-clinical mammalian model also applies to the human. In both, the pre-clinical and the human model, microscale substructures are described as a collection of simple geometrical shapes akin to those used in the Cristy-Eckerman phantoms for normal organs. Anatomical parameters are taken from the literature for a human model, while murine parameters are measured ex vivo. The murine histological slides also provide the data for volume of occupancy of the different compartments of the nephron in the kidney: glomerulus versus proximal tubule versus distal tubule. Monte Carlo simulations are run with activity placed in the different nephron compartments for several α-particle emitters currently under investigation in radiopharmaceutical therapy. The S-values were calculated for the α-emitters and their descendants between the different nephron compartments for both the

  16. A nephron-based model of the kidneys for macro-to-micro α-particle dosimetry

    PubMed Central

    Hobbs, Robert F; Song, Hong; Huso, David L; Sundel, Margaret; Sgouros, George

    2013-01-01

    Objective Targeted α-particle therapy is a promising treatment modality for cancer. Due to the short path-length of α-particles, the potential efficacy and toxicity of these agents is best evaluated by microscale dosimetry calculations instead of whole-organ, absorbed fraction –based dosimetry. Yet time-integrated activity (TIA), the necessary input for dosimetry, can still only be quantified reliably at the organ or macroscopic level. We describe a nephron- and cellular-based kidney dosimetry model for α-particle radiopharmaceutical therapy, more suited to the short range and high linear energy transfer of α-particle emitters, which takes as input kidney or cortex TIA and through a macro to micro model-based methodology assigns TIA to micro-level kidney substructures. We apply the model to provide nephron-level S-values for a range of isotopes allowing for pre-clinical and clinical applications according to the medical internal radiation dosimetry (MIRD) schema. Methods We assume that the relationship between whole-organ TIA and TIA apportioned to microscale substructures as measured in an appropriate pre-clinical mammalian model also applies to the human. In both, the pre-clinical and the human model, microscale substructures are described as a collection of simple geometrical shapes akin go those used in the Cristy-Eckermann phantoms for normal organs. Anatomical parameters are taken from the literature for a human model, while murine parameters are measured, ex vivo. The murine histological slides also provide the data for volume of occupancy of the different compartments of the nephron in the kidney: glomerulus vs. proximal tubule vs. distal tubule. Monte Carlo simulations are run with activity placed in the different nephron compartments for several α-particle emitters currently under investigation in radiopharmaceutical therapy. Results The S-values were calculated for the α-emitters and their descendants between the different nephron compartments

  17. Permanent Breast Seed Implant Dosimetry Quality Assurance

    SciTech Connect

    Keller, Brian M.; Ravi, Ananth; Sankreacha, Raxa; Pignol, Jean-Philippe

    2012-05-01

    Purpose: A permanent breast seed implant is a novel method of accelerated partial breast irradiation for women with early-stage breast cancer. This article presents pre- and post-implant dosimetric data, relates these data to clinical outcomes, and makes recommendations for those interested in starting a program. Methods and Materials: A total of 95 consecutive patients were accrued into one of three clinical trials after breast-conserving surgery: a Phase I/II trial (67 patients with infiltrating ductal carcinoma); a Phase II registry trial (25 patients with infiltrating ductal carcinoma); or a multi-center Phase II trial for patients with ductal carcinoma in situ (3 patients). Contouring of the planning target volume (PTV) was done on a Pinnacle workstation and dosimetry calculations, including dose-volume histograms, were done using a Variseed planning computer. Results: The mean pre-implant PTV coverage for the V{sub 90}, V{sub 100}, V{sub 150}, and V{sub 200} were as follows: 98.8% {+-} 1.2% (range, 94.5-100%); 97.3% {+-} 2.1% (range, 90.3-99.9%), 68.8% {+-} 14.3% (range, 32.7-91.5%); and 27.8% {+-} 8.6% (range, 15.1-62.3%). The effect of seed motion was characterized by post-implant dosimetry performed immediately after the implantation (same day) and at 2 months after the implantation. The mean V{sub 100} changed from 85.6% to 88.4% (p = 0.004) and the mean V{sub 200} changed from 36.2% to 48.3% (p < 0.001). Skin toxicity was associated with maximum skin dose (p = 0.014). Conclusions: Preplanning dosimetry should aim for a V{sub 90} of approximately 100%, a V{sub 100} between 95% and 100%, and a V{sub 200} between 20% and 30%, as these numbers are associated with no local recurrences to date and good patient tolerance. In general, the target volume coverage improved over the duration of the seed therapy. The maximum skin dose, defined as the average dose over the hottest 1 Multiplication-Sign 1-cm{sup 2} surface area, should be limited to 90% of the

  18. 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

  19. Gamma-ray dosimetry measurements of the Little Boy replica

    SciTech Connect

    Plassmann, E.A.; Pederson, R.A.

    1984-01-01

    We present the current status of our gamma-ray dosimetry results for the Little Boy replica. Both Geiger-Mueller and thermoluminescent detectors were used in the measurements. Future work is needed to test assumptions made in data analysis.

  20. MECHANISTIC DOSIMETRY MODELS OF NANOMATERIAL DEPOSITION IN THE RESPIRATORY TRACT

    EPA Science Inventory

    Accurate health risk assessments of inhalation exposure to nanomaterials will require dosimetry models that account for interspecies differences in dose delivered to the respiratory tract. Mechanistic models offer the advantage to interspecies extrapolation that physicochemica...