WorldWideScience

Sample records for dosimetry study evaluating

  1. Characterization and evaluation studies on some JAERI dosimetry systems

    International Nuclear Information System (INIS)

    Kojima, T.; Sunaga, H.; Tachibana, H.; Takizawa, H.; Tanaka, R.

    2000-01-01

    Characterization and evaluation studies were carried out on some JAERI dosimetry systems, mainly alanine-ESR, in terms of the influence on the dose response of parameters such as orientation at ESR analysis, and the temperature during irradiation and analysis. Feasibility study for application of these dosimetry systems to electrons with energies lower than 4 MeV and bremsstrahlung (X rays) was also performed parallel to their reliability check through international dose intercomparison. (author)

  2. A review of dosimetry used in epidemiological studies considered to evaluate the linear no-threshold (LNT) dose-response model for radiation protection.

    Science.gov (United States)

    Till, John E; Beck, Harold L; Grogan, Helen A; Caffrey, Emily A

    2017-10-01

    Accurate dosimetry is key to deriving the dose response from radiation exposure in an epidemiological study. It becomes increasingly important to estimate dose as accurately as possible when evaluating low dose and low dose rate as the calculation of excess relative risk per Gray (ERR/Gy) is very sensitive to the number of excess cancers observed, and this can lead to significant errors if the dosimetry is of poor quality. By including an analysis of the dosimetry, we gain a far better appreciation of the robustness of the work from the standpoint of its value in supporting the shape of the dose response curve at low doses and low dose rates. This article summarizes a review of dosimetry supporting epidemiological studies currently being considered for a re-evaluation of the linear no-threshold assumption as a basis for radiation protection. The dosimetry for each study was evaluated based on important attributes from a dosimetry perspective. Our dosimetry review consisted of dosimetry supporting epidemiological studies published in the literature during the past 15 years. Based on our review, it is clear there is wide variation in the quality of the dosimetry underlying each study. Every study has strengths and weaknesses. The article describes the results of our review, explaining which studies clearly stand out for their strengths as well as common weaknesses among all investigations. To summarize a review of dosimetry used in epidemiological studies being considered by the National Council on Radiation Protection and Measurements (NCRP) in an evaluation of the linear no-threshold dose-response model that underpins the current framework of radiation protection. The authors evaluated each study using criteria considered important from a dosimetry perspective. The dosimetry analysis was divided into the following categories: (1) general study characteristics, (2) dose assignment, (3) uncertainty, (4) dose confounders (5) dose validation, and (6) strengths and

  3. MRI evaluation and image processing in gel dosimetry. A study of selected MRI properties and image processing in 3D gel dosimetry

    International Nuclear Information System (INIS)

    Magnusson, Peter

    2001-03-01

    Gel dosimetry is a new dosimetry method applied in radiation therapy. Gel dosimeters consist of a radiation sensitive gel, which can integrate absorbed doses from several radiation sources or beams. The dose to the gel can be evaluated by magnetic resonance imaging (MRI), a procedure that is the focus of the present thesis. A robust tool for the evaluation of the nonuniformity in MRI has been developed, the Deviation Image method. Unlike previously presented methods, the Deviation Image method includes all nonuniformity variations across a phantom surface and is insensitive to stochastic noise. Methods for the estimation of stochastic noise were analyzed in terms of sensitivity to nonuniformities. A method that averages the stochastic noise level over five regions over the phantom surface, and a method that assesses the stochastic noise level from the background, were found to be the methods of choice. Pronounced MR image nonuniformity variation with repetition and T1 relaxation time was observed in the spin-echo T1 measurement protocol. These variations were caused by nonuniform RF transmission in combination with the inherent differences in the allowance of T1 relaxation for different repetition times. Neither the T1 calculation itself, the uniformity optimized repetition times, nor the correction methods could sufficiently correct for these nonuniformities. The nonuniformities were found to vary considerably less with inversion time for the inversion recovery pulse sequence, resulting in a T1 image with considerably lower nonuniformity. A multi-spin-echo pulse sequence using the 3D volume acquisition technique was developed that was capable of evaluating polyacrylamide gel dosimeters with an equal resolution of 1 mm in all three spatial dimensions. Expected advantages for the 3D technique in favor of the 2D techniques, could not be achieved in the actual measurements. Further development and studies of the 3D technique are therefore required, prior to its

  4. Neutron generator (HIRRAC) and dosimetry study.

    Science.gov (United States)

    Endo, S; Hoshi, M; Takada, J; Tauchi, H; Matsuura, S; Takeoka, S; Kitagawa, K; Suga, S; Komatsu, K

    1999-12-01

    Dosimetry studies have been made for neutrons from a neutron generator at Hiroshima University (HIRRAC) which is designed for radiobiological research. Neutrons in an energy range from 0.07 to 2.7 MeV are available for biological irradiations. The produced neutron energies were measured and evaluated by a 3He-gas proportional counter. Energy spread was made certain to be small enough for radiobiological studies. Dose evaluations were performed by two different methods, namely use of tissue equivalent paired ionization chambers and activation of method with indium foils. Moreover, energy deposition spectra in small targets of tissue equivalent materials, so-called lineal energy spectrum, were also measured and are discussed. Specifications for biological irradiation are presented in terms of monoenergetic beam conditions, dose rates and deposited energy spectra.

  5. Dosimetry

    International Nuclear Information System (INIS)

    Anon.

    1990-01-01

    The purpose of ionizing radiation dosimetry is the measurement of the physical and biological consequences of exposure to radiation. As these consequences are proportional to the local absorption of energy, the dosimetry of ionizing radiation is based on the measurement of this quantity. Owing to the size of the effects of ionizing radiation on materials in all of these area, dosimetry plays an essential role in the prevention and the control of radiation exposure. Its use is of great importance in two areas in particular where the employment of ionizing radiation relates to human health: radiation protection, and medical applications. Dosimetry is different for various reasons: owing to the diversity of the physical characteristics produced by different kinds of radiation according to their nature (X- and γ-photons, electrons, neutrons,...), their energy (from several keV to several MeV), the orders of magnitude of the doses being estimated (a factor of about 10 5 between diagnostic and therapeutic applications); and the temporal and spatial variation of the biological parameters entering into the calculations. On the practical level, dosimetry poses two distinct yet closely related problems: the determination of the absorbed dose received by a subject exposed to radiation from a source external to his body (external dosimetry); and the determination of the absorbed dose received by a subject owing to the presence within his body of some radioactive substance (internal dosimetry)

  6. Dosimetry

    International Nuclear Information System (INIS)

    Rezende, D.A.O. de

    1976-01-01

    The fundamental units of dosimetry are defined, such as exposure rate, absorbed dose and equivalent dose. A table is given of relative biological effectiveness values for the different types of radiation. The relation between the roentgen and rad units is calculated and the concepts of physical half-life, biological half-life and effective half-life are discussed. Referring to internal dosimetry, a mathematical treatment is given to β particle-and γ radiation dosimetry. The absorbed dose is calculated and a practical example is given of the calculation of the exposure and of the dose rate for a gama source [pt

  7. A European neutron dosimetry intercomparison project (ENDIP). Results and evaluation

    International Nuclear Information System (INIS)

    Broerse, J.J.; Burger, G.; Coppola, M.

    1978-01-01

    A total of twenty groups from nine countries participated in sessions of the European Neutron Dosimetry Intercomparison Project (ENDIP) which were held during 1975 at GSF, Munich-Neuherberg and TNO, Rijswijk. The data of all participants are collected, the analysis and evaluation of the results are given in the present report. Specific chapters deal with the experimental arrangements and monitoring results at GSF and TNO, characteristics of the dosimetry systems employed by the paticipating groups and the basic physical data and correction factors employed for the determination of kerma and absorbed dose. In general, the participants in ENDIP quote systematic uncertainties of 7 to 8% in the neutron and total kerma or absorbed dose, which are mainly attributed to inadequate knowledge of basic constants. The variations in the results obtained by different participants seem to be in accordance with the relative large systematic uncertainties quoted. In order to determine the influence of the use of different values for the physical parameters, the relative responses of the participants' dosimeters have also been compared. The variances of quoted kerma and dose values are of the same order of magnitude as those of instrument responses. This result indicates inconsistencies in experimental techniques employed by the participants for the determination of kerma and absorbed dose. A separate nonparametric analysis of the ENDIP results confirmed that there are considerable systematic differences. Recommendations for future studies on neutron dosimetry for biological and medical applications are given at the end of the report

  8. Evaluating the Application of Tissue-Specific Dose Kernels Instead of Water Dose Kernels in Internal Dosimetry : A Monte Carlo Study

    NARCIS (Netherlands)

    Moghadam, Maryam Khazaee; Asl, Alireza Kamali; Geramifar, Parham; Zaidi, Habib

    2016-01-01

    Purpose: The aim of this work is to evaluate the application of tissue-specific dose kernels instead of water dose kernels to improve the accuracy of patient-specific dosimetry by taking tissue heterogeneities into consideration. Materials and Methods: Tissue-specific dose point kernels (DPKs) and

  9. Dosimetry treatment planning with uncertainty evaluation

    International Nuclear Information System (INIS)

    Henriquez, Francisco Cutanda; Castrillyn, Silvia Vargas

    2010-01-01

    Treatment planning results can be presented as a dosimetry report, consisting of a number of images, curves, indices, etc. and in a prescription for the delivery of the planned treatment. A complex decision process is needed in order to decide which the optimal plan is. Since this decision is based on dose computations with their associated uncertainty, a modern treatment planning process has to deal with the effects of uncertainty to achieve maximum accuracy. Several tools are presented allowing the user to work with uncertainty. Modified dose volume histograms can help evaluate competing plans so that a proper hierarchy can be established amongst different goals. Material/Methods: A central estimate of a dose volume histogram curve and two limit curves define an 'indifference' band in the dose volume plane. Every plan within this band can be considered not better than the initial one, because uncertainty does not allow telling them apart. If a DVH goal is met within the indifference band, the user can aim to improve a different goal. Results: The methods proposed in this work are easily introduced in clinical practice. They are compatible with an iterative optimization process adding few steps to the computation. Conclusion: Accuracy requirements in radiation therapy keep on increasing, while accuracy in dose measurement or modeling is only moderately improving. Although it is a minor part in the overall uncertainty budget for the treatment, computation uncertainty affects decision making. Our method help make decisions with a maximum of information. This novel method can also provide quantitative measures of the probability of achieving the goals.(Author)

  10. Quantitative evaluation of patient-specific quality assurance using online dosimetry system

    Science.gov (United States)

    Jung, Jae-Yong; Shin, Young-Ju; Sohn, Seung-Chang; Min, Jung-Whan; Kim, Yon-Lae; Kim, Dong-Su; Choe, Bo-Young; Suh, Tae-Suk

    2018-01-01

    In this study, we investigated the clinical performance of an online dosimetry system (Mobius FX system, MFX) by 1) dosimetric plan verification using gamma passing rates and dose volume metrics and 2) error-detection capability evaluation by deliberately introduced machine error. Eighteen volumetric modulated arc therapy (VMAT) plans were studied. To evaluate the clinical performance of the MFX, we used gamma analysis and dose volume histogram (DVH) analysis. In addition, to evaluate the error-detection capability, we used gamma analysis and DVH analysis utilizing three types of deliberately introduced errors (Type 1: gantry angle-independent multi-leaf collimator (MLC) error, Type 2: gantry angle-dependent MLC error, and Type 3: gantry angle error). A dosimetric verification comparison of physical dosimetry system (Delt4PT) and online dosimetry system (MFX), gamma passing rates of the two dosimetry systems showed very good agreement with treatment planning system (TPS) calculation. For the average dose difference between the TPS calculation and the MFX measurement, most of the dose metrics showed good agreement within a tolerance of 3%. For the error-detection comparison of Delta4PT and MFX, the gamma passing rates of the two dosimetry systems did not meet the 90% acceptance criterion with the magnitude of error exceeding 2 mm and 1.5 ◦, respectively, for error plans of Types 1, 2, and 3. For delivery with all error types, the average dose difference of PTV due to error magnitude showed good agreement between calculated TPS and measured MFX within 1%. Overall, the results of the online dosimetry system showed very good agreement with those of the physical dosimetry system. Our results suggest that a log file-based online dosimetry system is a very suitable verification tool for accurate and efficient clinical routines for patient-specific quality assurance (QA).

  11. Dosimetry; La dosimetrie

    Energy Technology Data Exchange (ETDEWEB)

    Le Couteulx, I.; Apretna, D.; Beaugerie, M.F. [Electricite de France (EDF), 75 - Paris (France)] [and others

    2003-07-01

    Eight articles treat the dosimetry. Two articles evaluate the radiation doses in specific cases, dosimetry of patients in radiodiagnosis, three articles are devoted to detectors (neutrons and x and gamma radiations) and a computer code to build up the dosimetry of an accident due to an external exposure. (N.C.)

  12. Evaluation of Dosimetry Check software for IMRT patient-specific quality assurance.

    Science.gov (United States)

    Narayanasamy, Ganesh; Zalman, Travis; Ha, Chul S; Papanikolaou, Niko; Stathakis, Sotirios

    2015-05-08

    The purpose of this study is to evaluate the use of the Dosimetry Check system for patient-specific IMRT QA. Typical QA methods measure the dose in an array dosimeter surrounded by homogenous medium for which the treatment plan has been recomputed. With the Dosimetry Check system, fluence measurements acquired on a portal dosimeter is applied to the patient's CT scans. Instead of making dose comparisons in a plane, Dosimetry Check system produces isodose lines and dose-volume histograms based on the planning CT images. By exporting the dose distribution from the treatment planning system into the Dosimetry Check system, one is able to make a direct comparison between the calculated dose and the planned dose. The versatility of the software is evaluated with respect to the two IMRT techniques - step and shoot and volumetric arc therapy. The system analyzed measurements made using EPID, PTW seven29, and IBA MatriXX, and an intercomparison study was performed. Plans from patients previously treated at our institution with treated anatomical site on brain, head & neck, liver, lung, and prostate were analyzed using Dosimetry Check system for any anatomical site dependence. We have recommendations and possible precautions that may be necessary to ensure proper QA with the Dosimetry Check system.

  13. Evaluation of uncertainty in dosimetry of irradiator system

    International Nuclear Information System (INIS)

    Santos, Gelson P.; Potiens, Maria P.A.; Vivolo, Vitor

    2005-01-01

    This paper describes the study of uncertainties in the estimates of dosimetry irradiator system STS 0B85 of LCI IPEN/CNEN-SP. This study is relevant for determination of best measurement capability when the laboratory performs routine calibrations of measuring radiation next the optimal measures designed to radioprotection. It is also a requirement for obtaining the accreditation of the laboratory by the INMETRO. For this dosimetry was used a reference system of the laboratory composed of a electrometer and a spherical ionization chamber of 1 liter. Measurements were made at five distances selected so to include the whole range of the optical bench tests and using three attenuators filters so as to extend the measurement capability. The magnitude used for evaluation was the rate of air kerma for 1 37C s and 6 0C o beams. Were carried out four series of measurements. It was verified the inverse square law to these series and their sets of uncertainty. Unfiltered, with one and two filters series showed good agreement with the inverse square low and the maximum uncertainty obtained was approximately 1.7%. In series with all the filters was a major deviation of the inverse square law and wide increase in uncertainty to measurements at the end of the optical bench

  14. Tenth ORNL Personnel Dosimetry Intercomparison Study

    International Nuclear Information System (INIS)

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

    1985-03-01

    The Tenth Personnel Dosimetry Intercomparison Study was conducted at the Oak Ridge National Laboratory during April 9-11, 1984. Dosemeter badges from 31 participating organizations were mounted on 40cm Lucite phantoms and exposed to a range of dose equivalents which could be encountered during routine personnel monitoring in mixed radiation fields. The Health Physics Research Reactor served as the only source of radiation for eight of the ten irradiations which included a low (approx. 0.50 mSv) and high (approx. 10.00 mSv) neutron dose equivalent run for each of four shield conditions. Two irradiations were also conducted for which concrete- and Lucite-shield reactor irradiations were gamma-enhanced using a 137 Cs source. Results indicated that some participants had difficulty obtaining measurable indication of neutron and gamma exposures at dose equivalents less than about 0.50 mSv and 0.20 mSv, respectively. Albedo dosemeters provided the best overall accuracy and precision for the neutron measurements. Direct interaction TLD systems showed significant variation in accuracy with incident spectrum, and threshold neutron dosemeters (film and recoil track) underestimated reference values by more than 50%. Gamma dose equivalents estimated in the mixed fields were higher than reference values with TL gamma dosemeters generally yielding more accurate results than film. Under the conditions of this study in which participants had information concerning exposure conditions and radiation field characteristics prior to dosemeter evaluation, only slightly more than half of all reported results met regulatory standards for neutron and gamma accuracy. 19 refs., 2 figs., 29 tabs

  15. Internal dosimetry for epidemiologic studies

    International Nuclear Information System (INIS)

    Groer, P.G.

    1987-01-01

    In traditional epidemiologic analyses, a single valued summary index, the standardized mortality ratio (SMR), is quite popular. The SMR is simply the ratio of the number of deaths observed in the study population to the number of deaths expected if the study population were subject to the age-specific rates of a standard population. SMRs for all causes or specific causes can be calculated. For such a simple analysis an exposed cohort is often characterized by an average organ or whole body dose or dose interval, and the necessary dose estimation effort is relatively minor. Modern statistical methods focus on the estimation of the cause-specific mortality rate λ for study populations exposed to ionizing radiations or toxic chemicals. The dependence of λ on factors other than demographic characteristics, such as race and sex, is usually described through a parametric model. Such factors, often called covariates or covariables, are incorporated in the mathematical expression for the hazard rate. The external gamma dose or the internal lung dose from inhaled uranium are good examples for covariates. This type of analysis permits the use of individual doses and gives a detailed and quantitative description of the mortality rate as a function of the covariables, but at the cost of a major dosimetric effort. The generation of the necessary dose information and also the calculational efforts become especially taxing for time-dependent covariates such as an internal, cumulative organ dose. 4 refs

  16. Evaluation of Personnel Dosimetry data in Guatemala

    International Nuclear Information System (INIS)

    Guillen, J.A.

    2002-01-01

    The purpose of this report is to present the evaluated data from external exposures of 1268 radiation workers in Guatemala carried out in the period of 1997-2000. The collective dose in medicine, industry and other applications shown a tendency to increase in the period of study, radiology is the practice that shown a trend to decrease, that could be explained as a result of inspections and personnel training carried out in this practice

  17. Evaluation of two-dimensional bolus effect of immobilization/support devices on skin doses: A radiochromic EBT film dosimetry study in phantom

    International Nuclear Information System (INIS)

    Chiu-Tsao, Sou-Tung; Chan, Maria F.

    2010-01-01

    Purpose: In this study, the authors have quantified the two-dimensional (2D) perspective of skin dose increase using EBT film dosimetry in phantom in the presence of patient immobilization devices during conventional and IMRT treatments. Methods: For 6 MV conventional photon field, the authors evaluated and quantified the 2D bolus effect on skin doses for six different common patient immobilization/support devices, including carbon fiber grid with Mylar sheet, Orfit carbon fiber base plate, balsa wood board, Styrofoam, perforated AquaPlast sheet, and alpha-cradle. For 6 and 15 MV IMRT fields, a stack of two film layers positioned above a solid phantom was exposed at the air interface or in the presence of a patient alpha-cradle. All the films were scanned and the pixel values were converted to doses based on an established calibration curve. The authors determined the 2D skin dose distributions, isodose curves, and cross-sectional profiles at the surface layers with or without the immobilization/support device. The authors also generated and compared the dose area histograms (DAHs) and dose area products from the 2D skin dose distributions. Results: In contrast with 20% relative dose [(RD) dose relative to d max on central axis] at 0.0153 cm in the film layer for 6 MV 10x10 cm 2 open field, the average RDs at the same depth in the film layer were 71%, 69%, 55%, and 57% for Orfit, balsa wood, Styrofoam, and alpha-cradle, respectively. At the same depth, the RDs were 54% under a strut and 26% between neighboring struts of a carbon fiber grid with Mylar sheet, and between 34% and 56% for stretched perforated AquaPlast sheet. In the presence of the alpha-cradle for the 6 MV (15 MV) IMRT fields, the hot spot doses at the effective measurement depths of 0.0153 and 0.0459 cm were 140% and 150% (83% and 89%), respectively, of the isocenter dose. The enhancement factor was defined as the ratio of a given DAH parameter (minimum dose received in a given area) with and without

  18. Evaluation of two-dimensional bolus effect of immobilization/support devices on skin doses: a radiochromic EBT film dosimetry study in phantom.

    Science.gov (United States)

    Chiu-Tsao, Sou-Tung; Chan, Maria F

    2010-07-01

    In this study, the authors have quantified the two-dimensional (2D) perspective of skin dose increase using EBT film dosimetry in phantom in the presence of patient immobilization devices during conventional and IMRT treatments. For 6 MV conventional photon field, the authors evaluated and quantified the 2D bolus effect on skin doses for six different common patient immobilization/support devices, including carbon fiber grid with Mylar sheet, Orfit carbon fiber base plate, balsa wood board, Styrofoam, perforated AquaPlast sheet, and alpha-cradle. For 6 and 15 MV IMRT fields, a stack of two film layers positioned above a solid phantom was exposed at the air interface or in the presence of a patient alpha-cradle. All the films were scanned and the pixel values were converted to doses based on an established calibration curve. The authors determined the 2D skin dose distributions, isodose curves, and cross-sectional profiles at the surface layers with or without the immobilization/support device. The authors also generated and compared the dose area histograms (DAHs) and dose area products from the 2D skin dose distributions. In contrast with 20% relative dose [(RD) dose relative to dmax on central axis] at 0.0153 cm in the film layer for 6 MV 10 x 10 cm2 open field, the average RDs at the same depth in the film layer were 71%, 69%, 55%, and 57% for Orfit, balsa wood, Styrofoam, and alpha-cradle, respectively. At the same depth, the RDs were 54% under a strut and 26% between neighboring struts of a carbon fiber grid with Mylar sheet, and between 34% and 56% for stretched perforated AquaPlast sheet. In the presence of the alpha-cradle for the 6 MV (15 MV) IMRT fields, the hot spot doses at the effective measurement depths of 0.0153 and 0.0459 cm were 140% and 150%, (83% and 89%), respectively, of the isocenter dose. The enhancement factor was defined as the ratio of a given DAH parameter (minimum dose received in a given area) with and without the support device. For 6

  19. Preparation, Biological Evaluation and Dosimetry Studies of 175Yb-Bis-Phosphonates for Palliative Treatment of Bone Pain

    Directory of Open Access Journals (Sweden)

    Ashraf Fakhari

    2015-10-01

    Full Text Available Objective: Optimized production and quality control of ytterbium-175 (Yb-175 labeled pamidronate and alendronate complexes as efficient agents for bone pain palliation has been presented. Methods: Yb-175 labeled pamidronate and alendronate (175Yb-PMD and 175Yb-ALN complexes were prepared successfully at optimized conditions with acceptable radiochemical purity, stability and significant hydroxyapatite absorption. The biodistribution of complexes were evaluated up to 48 h, which demonstrated significant bone uptake ratios for 175Yb-PAM at all-time intervals. It was also detected that 175Yb-PAM mostly washed out and excreted through the kidneys. Results: The performance of 175Yb-PAM in an animal model was better or comparable to other 175Yb-bone seeking complexes previously reported. Conclusion: Based on calculations, the total body dose for 175Yb-ALN is 40% higher as compared to 175Yb-PAM (especially kidneys indicating that 175Yb-PAM is probably a safer agent than 175Yb-ALN.

  20. Dosimetry in support of wholesomeness studies

    International Nuclear Information System (INIS)

    Jarrett, R.D.; Halliday, J.W.

    1979-01-01

    Interest in dosimetry procedures in the context of a large-scale processing situation exceeds the purely documentary aspects of this report. The numerous combinations afforded by the various types, strengths and configurations of irradiation sources and the possibilities for various conveyors and other facility design factors impacting on irradiation logistics render a completely general treatment of dosimetry procedures in such instances almost impossible. While the exact combination of these various factors represented by the irradiation facilities at NARADCOM may be duplicated nowhere else, the dosimetry procedures documented in this report offer both experience and solutions that might be more generally useful. Therefore, this report complements and supplements more general discussions found in the literature and cited in the text

  1. Implementation and evaluation of a transit dosimetry system for treatment verification

    OpenAIRE

    Ricketts, K.; Navarro, C.; Lane, K.; Moran, M.; Blowfield, C.; Kaur, U.; Cotten, G.; Tomala, D.; Lord, C.; Jones, J.; Adeyemi, A.

    2016-01-01

    PURPOSE: To evaluate a formalism for transit dosimetry using a phantom study and prospectively evaluate the protocol on a patient population undergoing 3D conformal radiotherapy. METHODS: Amorphous silicon EPIDs were calibrated for dose and used to acquire images of delivered fields. The measured EPID dose map was back-projected using the planning CT images to calculate dose at pre-specified points within the patient using commercially available software, EPIgray (DOSIsoft, France). This soft...

  2. Evaluation of nuclear data for neutron dosimetry

    International Nuclear Information System (INIS)

    Tardelli, Tiago Cardoso

    2013-01-01

    Absorbed dose and Effective dose are usually calculated using radiation transport computer codes. The quality of the calculations of absorbed dose depends on nuclear data utilized, however, there are rare information about the differences in dose caused by the use of different libraries. The objective of this study is to compare dose values obtained using different nuclear data libraries due to external source of neutrons in the energy range from 10-11 to 20 MeV. The nuclear data libraries used are: JENDL 4.0, JEFF 3.3.1 and ENDF/B.VII. Dose calculations were carried out with the MCNPX code considering the anthropomorphic ICRP 110 model. The differences in the absorbed dose values using JEFF 3.3.1 and ENDF/B.VII libraries are small, around 1%, but the results obtained with JENDL 4.0 presented differences up to 85% compared to ENDF and JEFF results. Differences in effective dose values are around 1.5% between ENDF and JEFF and 11% between ENDF/B.VII and JENDL 4.0. (author)

  3. Statistical methods to evaluate thermoluminescence ionizing radiation dosimetry data

    Energy Technology Data Exchange (ETDEWEB)

    Segre, Nadia; Matoso, Erika; Fagundes, Rosane Correa, E-mail: nadia.segre@ctmsp.mar.mil.b [Centro Tecnologico da Marinha em Sao Paulo (CEA/CTMSP), Ipero, SP (Brazil). Centro Experimental Aramar

    2011-07-01

    Ionizing radiation levels, evaluated through the exposure of CaF{sub 2}:Dy thermoluminescence dosimeters (TLD- 200), have been monitored at Centro Experimental Aramar (CEA), located at Ipero in Sao Paulo state, Brazil, since 1991 resulting in a large amount of measurements until 2009 (more than 2,000). The data amount associated with measurements dispersion, since every process has deviation, reinforces the utilization of statistical tools to evaluate the results, procedure also imposed by the Brazilian Standard CNEN-NN-3.01/PR- 3.01-008 which regulates the radiometric environmental monitoring. Thermoluminescence ionizing radiation dosimetry data are statistically compared in order to evaluate potential CEA's activities environmental impact. The statistical tools discussed in this work are box plots, control charts and analysis of variance. (author)

  4. Nuclear accident dosimetry studies at Los Alamos National Laboratory

    International Nuclear Information System (INIS)

    Casson, W.H.; Buhl, T.E.; Upp, D.L.

    1995-01-01

    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

  5. Definition study of the project Dosimetry Brachytherapy

    International Nuclear Information System (INIS)

    Bultman, J.

    1989-05-01

    The purpose of the research project Dosimetry Brachytherapy is the standardization of calibration methods and quality control procedures used for Brachytherapy sources. Proposals to develop measurement standards and methods for calibrating these sources are presented. Brachytherapy sources will be calibrated in terms of reference airkerma rate or in terms of absorbed dose in water. Therefore, in this project, special attention will be given to the in-phantom measurement method described by Meertens and the use of re-entrant ionisation chambers as transfer standards. In this report, a workplan and time schedule is included. (author). 19 refs.; 1 fig

  6. A transferability study of the EPR-tooth-dosimetry technique

    International Nuclear Information System (INIS)

    Sholom, S.; Chumak, V.; Desrosiers, M.; Bouville, A.

    2006-01-01

    The transferability of a measurement protocol from one laboratory to another is an important feature of any mature, standardised protocol. The electron paramagnetic resonance (EPR)-tooth dosimetry technique that was developed in Scientific Center for Radiation Medicine, AMS (Ukraine) (SCRM) for routine dosimetry of Chernobyl liquidators has demonstrated consistent results in several inter-laboratory measurement comparisons. Transferability to the EPR dosimetry laboratory at the National Inst. of Standards and Technology (NIST) was examined. Several approaches were used to test the technique, including dose reconstruction of SCRM-NIST inter-comparison samples. The study has demonstrated full transferability of the technique and the possibility to reproduce results in a different laboratory environment. (authors)

  7. Evaluation of thermoluminescent dosimeters using water equivalent phantoms for application in clinical electrons beams dosimetry

    International Nuclear Information System (INIS)

    Bravim, Amanda

    2010-01-01

    The dosimetry in Radiotherapy provides the calibration of the radiation beam as well as the quality control of the dose in the clinical routine. Its main objective is to determine with greater accuracy the dose absorbed by the tumor. This study aimed to evaluate the behavior of three thermoluminescent dosimeters for the clinical electron beam dosimetry. The performance of the calcium sulfate detector doped with dysprosium (CaSO 4 : Dy) produced by IPEN was compared with two dosimeters commercially available by Harshaw. Both are named TLD-100, however they differ in their dimensions. The dosimeters were evaluated using water, solid water (RMI-457) and PMMA phantoms in different exposure fields for 4, 6, 9, 12 and 16 MeV electron beam energies. It was also performed measurements in photon beams of 6 and 15 MV (2 and 5 MeV) only for comparison. The dose-response curves were obtained for the 60 Co gamma radiation in air and under conditions of electronic equilibrium, both for clinical beam of photons and electrons in maximum dose depths. The sensitivity, reproducibility, intrinsic efficiency and energy dependence response of dosimeters were studied. The CaSO 4 : Dy showed the same behavior of TLD-100, demonstrating only an advantage in the sensitivity to the beams and radiation doses studied. Thus, the dosimeter produced by IPEN can be considered a new alternative for dosimetry in Radiotherapy departments. (author)

  8. Needs for evaluated covariance data for reactor pressure vessel dosimetry

    International Nuclear Information System (INIS)

    Maerker, R.E.; Broadhead, B.L.; Wagschal, J.J.

    1992-01-01

    This report discusses new methodology for quantifying and then reducing uncertainties in the calculated pressure vessel fluences of a pressurized water reactor (PWR). The technique involves combining the integral results of the calculated and measured PWR surveillance dosimetry activities with the differential data used in the calculations, along with covariances of all the quantities, into a generalized linear least-squares adjustment procedure. Based on analysis of both PWRs and test reactor benchmarks, substantial evidence now exists to support the conclusion that, of all the nuclear as well as non-nuclear differential data considered, ENDF/B-VI values of the total inelastic iron cross sections and their covariances are the most important data controlling the outcome of the adjustment procedure. Predicted adjustments in these cross sections provided the stimulus for new measurements, the results of which impacted the ENDF/B-VI evaluation of iron 56

  9. Sixteenth nuclear accident dosimetry intercomparison study: August 13-17, 1979

    International Nuclear Information System (INIS)

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

    1980-12-01

    The Sixteenth Nuclear Accident Dosimetry Intercomparison Study was conducted August 13-17, 1979, at the Oak Ridge National Laboratory (ORNL). Nuclear criticality accidents with three different neutron and gamma energy spectra were simulated using the Health Physics Research Reactor (HPRR) operated in the pulse mode with different shielding configurations. Participants from 13 organizations exposed dosimeters set up as area monitors and mounted on phantoms for personnel monitoring. The composite of all reported dose results failed to meet nuclear criticality accident dosimetry guidelines which suggest accuracies of +-25% for neutron dose and +-20% for gamma dose. This indicates that continued development and evaluation of criticality accident dosimetry systems and analysis techniques are necessary to improve measurement accuracy so that existing standards can be met

  10. Seventeenth nuclear accident dosimetry intercomparison study: August 11-15, 1980

    International Nuclear Information System (INIS)

    Swaja, R.E.; Greene, R.T.

    1981-04-01

    The Seventeenth Nuclear Accident Dosimetry Intercomparison Study was conducted August 11-15, 1980, at the Oak Ridge National Laboratory. Nuclear criticality accidents with three different neutron and gamma ray energy spectra were simulated by operating the Health Physics Research Reactor in the pulse mode. Participants from 13 organizations exposed dosimeters set up as area monitors and mounted on phantoms for personnel monitoring. Analysis of experimental results reported by participants showed that less than 60% of the neutron dose measurements using foil activation, thermoluminescent, or sodium activation methods and less than 20% of the gamma dose measurements using thermoluminescent dosimeters met nuclear criticality accident dosimetry guidelines which suggest accuracies of +-25% for neutron dose and +-20% for gamma dose. This indicates that continued development and evaluation of criticality accident dosimetry systems for area and personnel monitoring are required to improve measurement accuracy so that existing standards can be met

  11. Study of the personal dosimetry service by thermoluminiscence

    International Nuclear Information System (INIS)

    Penaherrera, Patricio; Buitron, Susana; Prado, Elizabeth; Ceron Fabiola

    1992-01-01

    This paper is concerned with the personal dosimetry service given by the Ecuadorian Atomic Energy Commission to radiation exposed workers in Ecuador. The study has taken in consideration the number of professionals working in Ecuador by province and by area of work, and also the radiation doses received by them during the period 1987-1990

  12. Evaluation of electronic imaging device portal 'Portal Dosimetry' in quality control in intensity modulated radiotherapy

    International Nuclear Information System (INIS)

    Watanabe, Erika Yumi

    2010-01-01

    In this paper we present commissioning testing and evaluation of the use of Varian's portal dosimetry in the quality assurance of intensity-modulated radiotherapy. The commissioning tests were performed to characterize the portal dosimetry in terms dosimetric and to assess the its possible application in radiotherapy. These tests demonstrated that portal dosimetry has all the characteristics to be used for dosimetry in radiotherapy such as linear response with dose, the independence of dose rate, reproducibility, and others. The evaluation of the use of portal dosimetry in quality control of IMRT was performed in two steps: assessing the ability of the device to detect errors deliberately introduced in simple and complex fluences. Errors of known magnitude were introduced in certain areas of fluences and was carried out quality control of these fluences with portal dosimetry and three dosimetric systems: ionization chamber, film and array of ionization chambers. The data obtained from the portal were compared with those of other devices and all were able to identify errors introduced satisfactorily, the values, normalized to the original fluence, obtained with the portal dosimetry were similar to the ionization chamber and the array of ion chambers (seven29) and differing in up to 2% of the values obtained with the films. The fluences measured with the portal dosimetry were evaluated both quantitatively and qualitatively. The index of the gamma function provided by software analysis of portal dosimetry showed no defined rules of behavior in relation to the errors introduced and for this reason the qualitative analysis has proved indispensable in cases evaluated. (author)

  13. ALARA dosimetry study for non productive radiation exposures in Pacific Northwest Laboratory facilities

    International Nuclear Information System (INIS)

    Hadlock, D.E.

    1981-04-01

    A special ALARA study was conducted during 1980 in selected Pacific Northwest Laboratory facilities. The study utilized thermoluminescent dosimeters (TLDs) which were designed to detect gamma, beta, and neutron exposures; however, only gamma exposures are evaluated in this report. The processing of ALARA (As Low As Reasonably Achievable) dosimeters was performed by the Dosimetry Technology Section of the Radiological Sciences Department. Evaluation of dosimetry data and locations was performed in conjunction with the Radiation Monitoring Section and the Radiological Safety and Engineering Section of the Occupational and Environmental Protection Department. This study was prompted by a DOE-RL directive to reduce radiation exposure to As Low As Reasonably Achievable (ALARA) with a goal of no personnel whole-body penetrating exposures exceeding 3 rem for calendar year 1980. The purpose of this study was to characterize the background radiation environment at selected locations within PNL facilities. Attention was focused on non productive radiation exposure received from the work environment

  14. Systematic evaluation of photodetector performance for plastic scintillation dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Boivin, Jonathan, E-mail: jonathan.boivin.1@ulaval.ca; Beaulieu, Luc [Département de Physique, de Génie physique et d’Optique, et Centre de recherche sur le cancer, Université Laval, Québec, Québec G1V 0A6, Canada and Département de Radio-Oncologie et Axe oncologie du Centre de recherche du CHU de Québec, CHU de Québec, Québec, Québec G1R 2J6 (Canada); Beddar, Sam [Department of Radiation Physics, University of Texas, MD Anderson Cancer Center, Houston, Texas 77030 (United States); Guillemette, Maxime [Département de Physique, de Génie physique et d’Optique, Université Laval, Québec, Québec G1V 0A6, Canada and Institut Universitaire de Cardiologie et de Pneumologie de Québec, Québec, Québec G1V 4G5 (Canada)

    2015-11-15

    Purpose: The authors’ objective was to systematically assess the performance of seven photodetectors used in plastic scintillation dosimetry. The authors also propose some guidelines for selecting an appropriate detector for a specific application. Methods: The plastic scintillation detector (PSD) consisted of a 1-mm diameter, 10-mm long plastic scintillation fiber (BCF-60), which was optically coupled to a clear 10-m long optical fiber of the same diameter. A light-tight plastic sheath covered both fibers and the scintillator end was sealed. The clear fiber end was connected to one of the following photodetectors: two polychromatic cameras (one with an optical lens and one with a fiber optic taper replacing the lens), a monochromatic camera with an optical lens, a PIN photodiode, an avalanche photodiode (APD), or a photomultiplier tube (PMT). A commercially available W1 PSD was also included in the study, but it relied on its own fiber and scintillator. Each PSD was exposed to both low-energy beams (120, 180, and 220 kVp) from an orthovoltage unit and high-energy beams (6 and 23 MV) from a linear accelerator. Various dose rates were tested to identify the operating range and accuracy of each photodetector. Results: For all photodetectors, the relative uncertainty was less than 5% for dose rates higher than 3 mGy/s. The cameras allowed multiple probes to be used simultaneously, but they are less sensitive to low-light signals. The PIN, APD, and PMT had higher sensitivity, making them more suitable for low dose rate and out-of-field dose monitoring. The relative uncertainty of the PMT was less than 1% at the lowest dose rate achieved (0.10 mGy/s), suggesting that it was optimal for use in live dosimetry. Conclusions: For dose rates higher than 3 mGy/s, the PIN diode is the most effective photodetector in terms of performance/cost ratio. For lower dose rates, such as those seen in interventional radiology or high-gradient radiotherapy, PMTs are the optimal choice.

  15. Personal dosimetry statistics and specifics of low dose evaluation

    International Nuclear Information System (INIS)

    Avila, R.E.; Gómez Salinas, R.A.; Oyarzún Cortés, C.H.

    2015-01-01

    The dose statistics of a personal dosimetry service, considering 35,000+ readings, display a sharp peak at low dose (below 0.5 mSv) with skewness to higher values. A measure of the dispersion is that approximately 65% of the doses fall below the average plus 2 standard deviations, an observation which may prove helpful to radiation protection agencies. Categorizing the doses by the concomitant use of a finger ring dosimeter, that skewness is larger in the whole body, and ring dosimeters. The use of Harshaw 5500 readers at high gain leads to frequent values of the glow curve that are judged to be spurious, i.e. values not belonging to the roughly normal noise over the curve. A statistical criterion is shown for identifying those anomalous values, and replacing them with the local behavior, as fit by a cubic polynomial. As a result, the doses above 0.05 mSv which are affected by more than 2% comprise over 10% of the data base. The low dose peak of the statistics, above, has focused our attention on the evaluation of LiF(Mg,Ti) dosimeters exposed at low dose, and read with Harshaw 5500 readers. The standard linear procedure, via an overall reader calibration factor, is observed to fail at low dose, in detailed calibrations from 0.02 mSv to 1 Sv. A significant improvement is achieved by a piecewise polynomials calibration curve. A cubic, at low dose is matched, at ∼10 mSv, in value and first derivative, to a linear dependence at higher doses. This improvement is particularly noticeable below 2 mSv, where over 60% of the evaluated dosimeters are found. (author)

  16. Studies on the Ozyorsk population: dosimetry

    International Nuclear Information System (INIS)

    Khokhryakov, Victor V.; Drozhko, Evgeniy G.; Glagolenko, Y V.; Rovny, Sergey I.; Vasilenko, E K.; Suslov, A; Anspaugh, L R.; Napier, Bruce A.; Bouville, A; Khokhryakov, V F.; Suslova, K G.; Romanov, S A.

    2001-01-01

    The Mayak Production Association (MPA) is located in the northern part of Chelyabinsk Oblast. Operating areas are about 10 km from the town of Ozyorsk, the largest populated area nearby, but other nearby populated areas include Novogorny Village, New Metlino Village, and Kyshtym Town. The long-term objective of this (unfunded) project is reconstruction of the time-dependent individual radiation doses to residents of Ozyorsk and the surrounding area from atmospheric releases of radionuclides from the facilities of the Mayak Production Association (MPA). The time period is from 1948 to the present. This information could be used in several epidemiologic studies of the regional population. Two pilotscale studies of thyroid disease among residents of Ozyorsk have found an increase in thyroid nodules among exposed persons compared to unexposed persons and an increase in thyroid carcinoma in Ozyorsk. The success of follow-on studies would depend upon the availability of thyroid doses proposed to be provided. The availability of credible thyroid doses would allow the quantification of risk of thyroid disease and the evaluation of factors such as host susceptibility, age and time effects, and gender differences. Perhaps more importantly, studies of the Ozyorsk residents would not be encumbered with the complications associated with previous early detection screening, as in the Chernobyl studies, or previous medical conditions, as in the I-131 medical studies. The releases to the atmosphere from MPA stacks are a source of exposure to other populations that are the subject of epidemiologic investigation; these populations include the Extended Techa River Cohort (JCCRER Direction 1), the MPA workers (JCCRER Direction 2), and proposed studies of the East Urals Radioactive Trace (EURT) cohort. The doses received by these cohorts from atmospheric releases at the MPA represent a confounding variable that cannot be considered without the information proposed to be provided

  17. Dose evaluation of three-dimensional small animal phantom with film dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Han, Su Chul [Div. of Medical Radiation Equipment, Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of); Park, Seung Woo [Radilogcial and Medico-Oncological Sciences, University of Sciences and Technology, Daejeon (Korea, Republic of)

    2017-03-15

    The weight of small animal dosimetry has been continuously increased in pre-clinical studies using radiation in small animals. In this study, three-dimensional(3D) small animal phantom was fabricated using 3D printer which has been continuously used and studied in the various fields. The absorbed dose of 3D animal phantom was evaluated by film dosimetry. Previously, the response of film was obtained from the materials used for production of 3D small animal phantom and compared with the bolus used as the tissue equivalent material in the radiotherapy. When irradiated with gamma rays from 0.5 Gy to 6 Gy, it was confirmed that there was a small difference of less than 1% except 0.5 Gy dose. And when small animal phantom was irradiated with 5 Gy, the difference between the irradiated dose and calculated dose from film was within 2%. Based on this study, it would be possible to increase the reliability of dose in pre-clinical studies using irradiation in small animals by evaluating dose of 3D small animal phantom.

  18. Dose evaluation of three-dimensional small animal phantom with film dosimetry

    International Nuclear Information System (INIS)

    Han, Su Chul; Park, Seung Woo

    2017-01-01

    The weight of small animal dosimetry has been continuously increased in pre-clinical studies using radiation in small animals. In this study, three-dimensional(3D) small animal phantom was fabricated using 3D printer which has been continuously used and studied in the various fields. The absorbed dose of 3D animal phantom was evaluated by film dosimetry. Previously, the response of film was obtained from the materials used for production of 3D small animal phantom and compared with the bolus used as the tissue equivalent material in the radiotherapy. When irradiated with gamma rays from 0.5 Gy to 6 Gy, it was confirmed that there was a small difference of less than 1% except 0.5 Gy dose. And when small animal phantom was irradiated with 5 Gy, the difference between the irradiated dose and calculated dose from film was within 2%. Based on this study, it would be possible to increase the reliability of dose in pre-clinical studies using irradiation in small animals by evaluating dose of 3D small animal phantom

  19. Study of a 3D dosimetry system response: ARCCHECK®

    Energy Technology Data Exchange (ETDEWEB)

    Mazer, Amanda C.; Yoriyaz, Hélio, E-mail: amandamazer18@gmail.com, E-mail: hyoriyaz@ipen.br [Instituto de Pesquisas Energéticas e Nucleares (IPEN/CNEN-SP), São Paulo, SP (Brazil); Nakandakari, Marcos V.N., E-mail: marcos.sake@gmail.com [Beneficência Portuguesa de São Paulo, SP (Brazil)

    2017-07-01

    Ionizing radiation therapies have improved over the years, becoming more specific for each patient. Thereby as the treatment planning system (TPS) complexities increases, the quality assurance (QA) methods have to be in a constant evolution. One of the techniques that demand great complexity is the Volumetric Modulated Arc Therapy (VMAT). One possible way to VMAT commissioning is using 3D dosimetry systems and recently a new 3D dosimetry system called ArcCheck had been developed and commercialized mainly for VMAT quality assurance. It is water-equivalent and composed by an array of 1386 diodes arranged in a spiral pattern. Since simulation methods, like Monte Carlo method, ensure highly accurate results, MCNP (A General Monte Carlo N-Particle Transport Code System) is totally reliable for problems that involve radiation transport. This work presents a preliminary study of the 3D dosimetry system ArcCheck by developing two computational models in MCNP6. In addition, experimental measures were acquired using the ArcCheck in a Linear Accelerator and then these values were compared with the results obtained by simulations of both models. The comparisons showed good reproducibility. (author)

  20. Pre-clinical evaluation of a diode-based In vivo dosimetry system

    Energy Technology Data Exchange (ETDEWEB)

    Trujillo, G. [National Oncology Institute, Havana (Cuba)

    1998-12-31

    Diode detector systems are routinely used in a number of departments for the quality assurance of the delivered dose in radiation oncology (1,2,3,4,5). The main advantage of diode detectors for in vivo dosimetry (over TLDs, film dosimetry, ionization chambers) is that results are immediately available in real time, do not need external bias voltage and are more sensitive for the same detection volume than ionization chambers thereby allowing a direct and immediate check of the treatment accuracy. Also, is important to mention that is possible to obtain different accuracy levels. For example, in the case of the measurements designed for evaluating the dosimetric accuracy of a new treatment technique for dose escalation studies the action level should be tighter (the order of 2 % to 4 %, 2 standard deviations) than for routine measurements aiming to discover and correct for errors in the treatment of individual patients ({+-} 5 % - 10 % or to avoid mis administrations (10 % - 15 %). This work describes the calibration method adopted and the evaluation of the accuracy and precision of in vivo dosimetry at Co 60 and 23 MV photon energies. Extensive phantoms measurements were made to determine the influence of physical conditions on the diode response. Parameters investigated included diode linearity, leakage, and measurement reproducibility, as well as the field size, SSD, and angular dependence. the practical consequences of these measurements are reported. There is still some controversy as to whether in vivo (diode) dosemeters are required for routine quality assurance purposes. Our work has shown that while care must be taken in choosing and handling diode detector systems they are able to provide an efficient and effective method of ensuring the dose delivered to the patient during treatment is within acceptable limits. (Author)

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

    Energy Technology Data Exchange (ETDEWEB)

    Sakhalkar, H. S.; Adamovics, J.; Ibbott, G.; Oldham, M. [Department of Radiation Oncology Physics, Duke University Medical Center, Durham, North Carolina 27710 (United States); Department of Chemistry and Biology, Rider University, Lawrenceville, New Jersey 08648 (United States); Department of Radiation Physics, M. D. Anderson Cancer Center, Houston, Texas 77030 (United States); Department of Radiation Oncology Physics, Duke University Medical Center, Durham, North Carolina 27710 (United States)

    2009-01-15

    This work presents extensive investigations to evaluate the robustness (intradosimeter consistency and temporal stability of response), reproducibility, precision, and accuracy of a relatively new 3D dosimetry system comprising a leuco-dye doped plastic 3D dosimeter (PRESAGE) and a commercial optical-CT scanner (OCTOPUS 5x scanner from MGS Research, Inc). Four identical PRESAGE 3D dosimeters were created such that they were compatible with the Radiologic Physics Center (RPC) head-and-neck (H and N) IMRT credentialing phantom. Each dosimeter was irradiated with a rotationally symmetric arrangement of nine identical small fields (1x3 cm{sup 2}) impinging on the flat circular face of the dosimeter. A repetitious sequence of three dose levels (4, 2.88, and 1.28 Gy) was delivered. The rotationally symmetric treatment resulted in a dose distribution with high spatial variation in axial planes but only gradual variation with depth along the long axis of the dosimeter. The significance of this treatment was that it facilitated accurate film dosimetry in the axial plane, for independent verification. Also, it enabled rigorous evaluation of robustness, reproducibility and accuracy of response, at the three dose levels. The OCTOPUS 5x commercial scanner was used for dose readout from the dosimeters at daily time intervals. The use of improved optics and acquisition technique yielded substantially improved noise characteristics (reduced to {approx}2%) than has been achieved previously. Intradosimeter uniformity of radiochromic response was evaluated by calculating a 3D gamma comparison between each dosimeter and axially rotated copies of the same dosimeter. This convenient technique exploits the rotational symmetry of the distribution. All points in the gamma comparison passed a 2% difference, 1 mm distance-to-agreement criteria indicating excellent intradosimeter uniformity even at low dose levels. Postirradiation, the dosimeters were all found to exhibit a slight increase in

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

    International Nuclear Information System (INIS)

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

    2009-01-01

    This work presents extensive investigations to evaluate the robustness (intradosimeter consistency and temporal stability of response), reproducibility, precision, and accuracy of a relatively new 3D dosimetry system comprising a leuco-dye doped plastic 3D dosimeter (PRESAGE) and a commercial optical-CT scanner (OCTOPUS 5x scanner from MGS Research, Inc). Four identical PRESAGE 3D dosimeters were created such that they were compatible with the Radiologic Physics Center (RPC) head-and-neck (H and N) IMRT credentialing phantom. Each dosimeter was irradiated with a rotationally symmetric arrangement of nine identical small fields (1x3 cm 2 ) impinging on the flat circular face of the dosimeter. A repetitious sequence of three dose levels (4, 2.88, and 1.28 Gy) was delivered. The rotationally symmetric treatment resulted in a dose distribution with high spatial variation in axial planes but only gradual variation with depth along the long axis of the dosimeter. The significance of this treatment was that it facilitated accurate film dosimetry in the axial plane, for independent verification. Also, it enabled rigorous evaluation of robustness, reproducibility and accuracy of response, at the three dose levels. The OCTOPUS 5x commercial scanner was used for dose readout from the dosimeters at daily time intervals. The use of improved optics and acquisition technique yielded substantially improved noise characteristics (reduced to ∼2%) than has been achieved previously. Intradosimeter uniformity of radiochromic response was evaluated by calculating a 3D gamma comparison between each dosimeter and axially rotated copies of the same dosimeter. This convenient technique exploits the rotational symmetry of the distribution. All points in the gamma comparison passed a 2% difference, 1 mm distance-to-agreement criteria indicating excellent intradosimeter uniformity even at low dose levels. Postirradiation, the dosimeters were all found to exhibit a slight increase in

  3. Consistency of external dosimetry in epidemiologic studies of nuclear workers

    International Nuclear Information System (INIS)

    Fix, J.J.; Gilbert, E.S.

    1992-05-01

    Efforts are underway to pool data from epidemiologic studies of nuclear workers to obtain more precise estimates of radiation risk than would be possible from any single study. The International Agency for Research on Cancer (IARC) is coordinating combined analyses of data from studies in the United States, Canada, and the United Kingdom. In the US, the Department of Energy (DOE) has established the Comprehensive Epidemiologic Data Resource (CEDR) to provide investigators an opportunity to analyze data from several DOE laboratories. IARC investigators, in collaboration with those conducting the individual studies, have developed a dosimetry protocol for the international combined analyses

  4. Consistency of external dosimetry in epidemiologic studies of nuclear workers

    International Nuclear Information System (INIS)

    Fix, J.J.; Gilbert, E.S.

    1992-01-01

    Efforts are underway to pool data from epidemiologic studies of nuclear workers to obtain more precise estimates of radiation risk than would be possible from any single study. The International Agency for Research on Cancer (IARC) is coordinating combined analyses of data from studies in the United States, Canada, and the United Kingdom. In the U.S., the Department of Energy (DOE) has established the Comprehensive Epidemiologic Data Resource (CEDR) to provide investigators an opportunity to analyze data from several DOE laboratories. IARC investigators, in collaboration with those conducting the individual studies, have developed a dosimetry protocol for the international combined analyses. (author)

  5. Testing and evaluating personal dosimetry services in 1976

    International Nuclear Information System (INIS)

    Plato, P.

    1978-01-01

    The National Sanitation Foundation (NSF) of Ann Arbor, Michigan, conducts an annual testing program for personal dosimetry services. In 1976, five processors participated in the testing program in order to be certified by NSF. Four other processors participated on a non-certification basis. Six of the participants are large commercial processors, and three are non-commercial, in-house processors. Some dosimetry services submitted film badges, some submitted thermoluminescent dosimeters, and some submitted both. This paper shows the results of all processors in each of nine radiation categories. The average performance of all the processors tested is good. The average reported quantity of radiation among the 927 dosimeters tested is within about 25% of the actual delivered quantity. However, the individual performance of some processors varies greatly from the average performance of all the processors. (author)

  6. Biological dosimetry study in differentiated thyroid carcinoma patients treated with 131Iodine

    International Nuclear Information System (INIS)

    Vallerga, Maria Belen

    2008-11-01

    , two blood samples were taken for each patient: 1) before the diagnostic 131 I study (to evaluate the contribution of previous therapeutic doses) and 2) after administration of the therapeutic activity. The dicentric assay and the chromosome painting technique (Fluorescence in situ Hybridization - FISH) were used. The application of different dose-effect calibration curves was examined. The chromosome aberration distribution among cells was analyzed, its relationship to clinical, biochemical and internal dosimetry data was investigated. Dose estimations from pre and post treatment samples were obtained and corrected for past and protracted exposures, respectively. In addition, the dose due to the current treatment was calculated and correlated with the internal dosimetry estimation. The application of biological dosimetry in these cases of internal 131 I incorporation is sustained by the results obtained. It is acceptable to use a 60 Co calibration curve for dose estimation of patients treated with 131 I, there is no need for applying correction factors. Significant deviations from Poisson were observed in chromosome aberration distribution among cells, mainly in patients with multiple or bone metastases and when the time in between radiotherapies was short. On the whole, patients who had suffered deterministic effects did not show evidences of inhomogeneity. The estimated dose values from the samples before radiotherapy support the idea that a three year half life is not enough for decay corrections in the order of months. It is not possible to settle on a single value of half life to apply due to the considerable variations between patients. Realistic adjustments for protracted overexposure dose estimation were achieved when a 6 h exposure time was considered. Correlation between whole body absorbed doses estimated by biological and internal dosimetry was found (p [es

  7. Dosimetry studies during breast cancer radiation treatment

    International Nuclear Information System (INIS)

    Ahmed, M. O. M.

    2005-06-01

    Previous studies indicated that breast cancer is wildly spread especially in women as compared to men. It is increased after an age of thirty five years in women so it is important to study the effect of exposure to the radiation on the intact breast during the treatment of the breast suffering from cancer. In this work the scattered doses for the intact breast during the treatment of the breast suffering from cancer were measured and also the probability of inducing cancer in it is also discussed. The study was performed for a group of patients composed of twenty five females. Also the backscattered doses to the intact breast were measured for thirteen female patients. During the treatment using gamma rays from Co-60 source the two tangential fields (lateral and medial) were selected for the measurements. The results of exposure to gamma radiation for the lateral and medial fields showed that the mean scattered and backscattered doses to the intact breast were (241.26 cGY,47.49 cGY) and (371.6 cGY,385.4 cGY), respectively. Beside that the somatic risk of induced cancer to the intact breast was found to be (6 .1X10 -3 ,1.2X10 -3 ) and (9.29X10 -3 , 9.63X10 -3 ), respectively. From the results obtained it was concluded that the intact breast received small amounts of radiation doses which may lead to breast cancer for the healthy breast. The recommendations from the present study are to take care of radiation protection to the patient, and also to take care of the patient treatment conditions like temperature, pressure and humidity during the radiation exposure.(Author)

  8. Comparative study of Si diodes for gamma radiation dosimetry

    International Nuclear Information System (INIS)

    Pascoalino, Kelly Cristina da Silva

    2010-01-01

    In this work it is presented the comparative study of Si diodes response for gamma radiation dosimetry. The diodes investigated, grown by float zone (Fz) and magnetic Czochralski (MCz) techniques, were processed at the Physics Institute of Helsinki University in the framework of the research and development of rad-hard silicon devices. To study the dosimetric response of these diodes they were connected in the photovoltaic mode to the input of a digital electrometer to measure the photocurrent signal due to the incidence of gamma-rays from a 60 Co source (Gammacell 220). The dosimetric parameter utilized to study the response of these devices was the charge, obtained trough the integration of the current signals, as a function of the absorbed dose. Studies of the influence of the pre-irradiation procedures on both sensitivity and stability of these diodes showed that the sensitivity decreased with the total absorbed dose but after a preirradiation of about 873 kGy they became more stable. Radiation damage effects eventually produced in the devices were monitored trough dynamic current and capacitance measurements after each irradiation step. Both samples also exhibited good response reproducibility, 2,21% (Fz) and 2,94% (MCz), obtained with 13 consecutive measurements of 15 kGy compared with the equivalent 195 kGy absorbed dose in one step of irradiation. It is important to note that these results are better than those obtained with routine polymethylmethacrylate (PMMA) dosimeters used in radiation processing dosimetry. (author)

  9. Dosimetry in computerized tomography and evaluation of doses in organs in thorax scanning

    International Nuclear Information System (INIS)

    Alonso, Thêssa Cristina

    2016-01-01

    Computed tomography has promoted improvement of the diagnostic process by producing anatomical cut images with high quality and contrast between soft tissues which have very similar absorption of the X-ray beams. The objective of this study is to evaluate the technological park of CT in Brazil correlated with the wide world, and carry out studies of experimental dosimetry to understand the dose distribution feature using phantoms and different methods of measurement of kerma index, as well as perform measures of local doses in sensitive organs. To study the scanner geographic distribution and supply of computed tomography tests in Brazil, a comparison has been made with results found with the specified reference by Brazilian law (Ordinance GM / MS No. 1101, 2002; Resolution RE nº1016, 2006). For dosimetry studies, It was used a standard chest phantom and the anthropomorphic phantom. For image quality evaluation, it was used the CATPHAN-600 phantom. Scans were performed in a GE scanner, Discovery model with 64 channels. Dose measurements have been performed by using a pencil ionization chamber, thermoluminescent dosimeters and radiochromic film strips. Sensitive organ shielding devices were evaluated in order to verify their efficiency in organ dose reduction and its influence in the quality of image. Considering Brazilian population, the scanner park showed a greater amount than the minimum parameter recommended by Brazilian law. Dose measurements using three different methods showed the correct procedure of metrological reliability of the measurement system. The findings and conclusions of this study may contribute to the improvement of local practices in Computed Tomography tests, inserted in context of radiological protection in order to define reference levels for optimized diagnosis, and image quality control. (author)

  10. Experimental and computational development of a natural breast phantom for dosimetry studies

    International Nuclear Information System (INIS)

    Nogueira, Luciana B.; Campos, Tarcisio P.R.

    2013-01-01

    This paper describes the experimental and computational development of a natural breast phantom, anthropomorphic and anthropometric for studies in dosimetry of brachytherapy and teletherapy of breast. The natural breast phantom developed corresponding to fibroadipose breasts of women aged 30 to 50 years, presenting radiographically medium density. The experimental breast phantom was constituted of three tissue-equivalents (TE's): glandular TE, adipose TE and skin TE. These TE's were developed according to chemical composition of human breast and present radiological response to exposure. Completed the construction of experimental breast phantom this was mounted on a thorax phantom previously developed by the research group NRI/UFMG. Then the computational breast phantom was constructed by performing a computed tomography (CT) by axial slices of the chest phantom. Through the images generated by CT a computational model of voxels of the thorax phantom was developed by SISCODES computational program, being the computational breast phantom represented by the same TE's of the experimental breast phantom. The images generated by CT allowed evaluating the radiological equivalence of the tissues. The breast phantom is being used in studies of experimental dosimetry both in brachytherapy as in teletherapy of breast. Dosimetry studies by MCNP-5 code using the computational model of the phantom breast are in progress. (author)

  11. SU-F-T-50: Evaluation of Monte Carlo Simulations Performance for Pediatric Brachytherapy Dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Chatzipapas, C; Kagadis, G [University Patras, Rion, Ahaia (Greece); Papadimitroulas, P [BET Solutions, Athens, Attiki (Greece); Loudos, G [Technological Educational Institute of Athens, Egaleo, Attiki (Greece); Papanikolaou, N [University of Texas HSC SA, San Antonio, TX (United States)

    2016-06-15

    Purpose: Pediatric tumors are generally treated with multi-modal procedures. Brachytherapy can be used with pediatric tumors, especially given that in this patient population low toxicity on normal tissues is critical as is the suppression of the probability for late malignancies. Our goal is to validate the GATE toolkit on realistic brachytherapy applications, and evaluate brachytherapy plans on pediatrics for accurate dosimetry on sensitive and critical organs of interest. Methods: The GATE Monte Carlo (MC) toolkit was used. Two High Dose Rate (HDR) 192Ir brachytherapy sources were simulated (Nucletron mHDR-v1 and Varian VS2000), and fully validated using the AAPM and ESTRO protocols. A realistic brachytherapy plan was also simulated using the XCAT anthropomorphic computational model .The simulated data were compared to the clinical dose points. Finally, a 14 years old girl with vaginal rhabdomyosarcoma was modelled based on clinical procedures for the calculation of the absorbed dose per organ. Results: The MC simulations resulted in accurate dosimetry in terms of dose rate constant (Λ), radial dose gL(r) and anisotropy function F(r,θ) for both sources.The simulations were executed using ∼1010 number of primaries resulting in statistical uncertainties lower than 2%.The differences between the theoretical values and the simulated ones ranged from 0.01% up to 3.3%, with the largest discrepancy (6%) being observed in the dose rate constant calculation.The simulated DVH using an adult female XCAT model was also compared to a clinical one resulting in differences smaller than 5%. Finally, a realistic pediatric brachytherapy simulation was performed to evaluate the absorbed dose per organ and to calculate DVH with respect to heterogeneities of the human anatomy. Conclusion: GATE is a reliable tool for brachytherapy simulations both for source modeling and for dosimetry in anthropomorphic voxelized models. Our project aims to evaluate a variety of pediatric

  12. Calculation of the uncertainty of HP (10) evaluation for a thermoluminescent dosimetry system

    International Nuclear Information System (INIS)

    Ferreira, M.S.; Silva, E.R.; Mauricio, C.L.P.

    2016-01-01

    Full interpretation of dose assessment only can be performed when the uncertainty of the measurement is known. The aim of this study is to calculate the uncertainty of the TL dosimetry system of the LDF/IRD for evaluation of H P (10) for photons. It has been done by experimental measurements, extraction of information from documents and calculation of uncertainties based on ISO GUM. Energy and angular dependence is the most important source to the combined u c (y) and expanded (U) uncertainty. For 10 mSv, it was obtained u c (y) = 1,99 mSv and U = 3,98 mSv for 95% of coverage interval. (author)

  13. Dosimetry implications of BSH biodistribution study at OSU

    International Nuclear Information System (INIS)

    Gupta, N.; Albertson, B.J.; Gahbauer, R.A.; Barth, R.F.; Goodman, J.H.

    2000-01-01

    A BSH biodistribution study was performed at Ohio State University, where tumor, normal brain, and blood boron concentrations of patients undergoing tumor debulking surgery were acquired. The results of this biodistribution study are subjects of other presentations in this meeting. In this paper, we present an overview of the dosimetry implications of this biodistribution data. The analysis for this paper assumed that the tumor boron RBE was factor of two higher than the normal brain boron RBE. Our conclusions from this analysis were that with the tumor/blood ratios observed in our patients for times of up to 14 hours post commencement of boron infusion, one could not successfully treat patients with BNCT using BSH. (author)

  14. Evaluation and development of X-ray detectors for dosimetry; Evaluierung und Entwicklung von Roentgendetektoren fuer die Dosimetrie

    Energy Technology Data Exchange (ETDEWEB)

    Boehnel, Michael

    2012-03-28

    This thesis presents the development and evaluation of a new personal dosemeter, based on the technology of energy-resolving pixelated photon-counting X-ray detectors. The basis of the development is a detailed study of the Timepix detector. The main focus is on the investigation of the energy resolving properties of the Timepix detector in counting mode and in the spectroscopic time-over-threshold mode. The approach for the production of fluorescence radiation for the detector calibration, necessary for the experiments, is presented. By using Monte Carlo simulations the spectral distribution of the resulting fluorescence spectra in dependence on the fluorescence material, the used primary X-ray radiation and the arrangement of the laboratory setup is discussed. Besides the actual fluorescence lines, the simulated calibration spectra also contain the background of scattered primary X-ray photons and fluorescence radiation contributions from parts of the experimental setup. Furthermore, the simulated spectra exhibit the corrected intensity conditions of the fluorescence emissions of the K- and L-shell. These calibration spectra permit a better match of measurements and simulations than the simplified fluorescence spectra used so far. For the detector calibration in counting mode, accelerated energy calibration methods are introduced. From measuring energy deposition spectra, the energy resolution of single pixels and the energy resolution of the complete detector could be determined by the application of a global energy calibration. It was shown that the influence of the threshold dispersion broadens the energy resolution of the single pixels, depending on the given energy deposition. The resulting energy resolution of the whole pixel matrix is thereby reduced. The negative effect of the threshold dispersion can be eliminated by the application of a single-pixel calibration. The relative energy resolution of the Timepix detector operated in the counting mode can

  15. Biological Dosimetry of X-rays by micronuclei study

    International Nuclear Information System (INIS)

    Gomez, E.; Silva, A.; Navlet, J.

    1991-01-01

    Biological dosimetry consists of estimating absorbed doses for people exposed to radiation by mean biological methods. Several indicators used are based in haematological, biochemical an cytogenetics data, although nowadays without doubt, the cytogenetic method is considered to be the most reliable, in this case, the study of micronuclei in peripheral blood lymphocytes citokinetics blocked can be related to absorbed dose through an experimental calibration curve. An experimental dose-response curve, using micronuclei assay for X-rays at 250 kVp, 43,79 rads/min and temperature 37 degree centigree has been produced. Experimental data is fitted to model Y=C+ αD+BD''2 where Y is the number of micronuclei per cell and D the dose. The curve is compared with those produced elsewhere. (Author) 24 refs

  16. Biological dosimetry of X-rays by micronuclei study

    International Nuclear Information System (INIS)

    Gomez, E.; Silva, A.; Navlet, J.

    1991-01-01

    Biological dosimetry consists of estimating absorbed doses for people exposed to radiation by mean biological methods. Several indicators used are based in hematological, biochemical an cytogenetics data, although nowadays without doubt, the cytogenetic method is considered to be the most reliable, in this case, the study of micronuclei in peripheral blood lymphocytes cytokinetic blocked can be related to absorbed dose through an experimental calibration curve. An experimental dose-response curve, using micronuclei assay for X-rays at 250 kVp, 43,79 rads/min and temperature 37 degree celsius has been produced. Experimental data is fitted to model Y=c+ α D+β D 2 where. Y is the number micronuclei per cell and D the dose. the curve is compared with those produced elsewhere

  17. Investigation of practical approaches to evaluating cumulative dose for cone beam computed tomography (CBCT) from standard CT dosimetry measurements: a Monte Carlo study.

    Science.gov (United States)

    Abuhaimed, Abdullah; Martin, Colin J; Sankaralingam, Marimuthu; Gentle, David J

    2015-07-21

    a CBCT scan over the 100 mm length. Like the Gx(L) function, the Gx(W)100 function showed only a weak dependency on tube potential at most positions for the phantoms studied. The results were fitted to polynomial equations from which f (0) within the longer PMMA, PE, or water phantoms can be evaluated from measurements of f 100(150)x. Comparisons with other studies, suggest that these functions may be suitable for application to any CT or CBCT scan acquired with stationary table mode.

  18. Evaluation of radiochromic films EBT3 for in-vivo dosimetry in radiotherapy treatments with photons

    International Nuclear Information System (INIS)

    Galvan de la C, O. O.; Rivera M, T.; Garcia G, O. A.; Larraga G, J. M.

    2015-10-01

    Full text: In-vivo dosimetry is a challenge in radiotherapy due to the measures are carried out in reference conditions outside; there is no balance of charged particle and beam consists of photons own and contamination electrons. Detectors that are useful for such measures should be sufficiently small and thin so they do not disturb the beam and do not alter the dose on target. In this paper the radiochromic films Gafchromic model EBT3 are evaluated as potential detectors for in-vivo dosimetry; measurements were carried out in solid water phantom on the surface, with films of dimensions 3 x 3 cm 2 . Irradiations were performed with a linear accelerator Novalis of 6 MV. Comparison between dose values found with a diode type Sfd detector (IBA dosimetry, Germany) and a diamond detector CVD (PTW-Freiburg) for 2 different sized of field (5 x 5 cm 2 and 10 x 10 cm 2 ) on the surface of a water phantom scanning was realized. The total spreading factor (Tsf) measured on surface was of 0.831 ± 4.6%; which is greater 12.9% than Tsf measured at a depth of maximum dose. This difference may be due to the contribution of scattered electrons to the beam exit. The measures must be corroborated with Monte Carlo simulations, which they will be validated on surface by the Abdel-Rahman [et al.] method; this mechanism will determine if the films are useful detectors for in-vivo dosimetry clinically. (Author)

  19. Thermoluminescent Dosimetry: A Preliminary Study for microCT Applications

    International Nuclear Information System (INIS)

    Montano Garcia, C.; Rodriguez-Villafuerte, M.; Martinez-Davalos, A.; Brandan, M. E.; Ruiz-Trejo, C.

    2006-01-01

    Preliminary measurements for microCT dosimetry are reported in this work, using TLD-100 crystals (1x1x1 mm3) within a solid water phantom specially designed with approximate dimensions of a mouse. A dose dependence as a function of radial distance and position along the axis of the phantom was found. Because of the smaller doses used in this work we can say that it is feasible to perform dosimetry measurements with high accuracy using TLD-100 microcubes

  20. Studies of photodynamic therapy: Investigation of physiological mechanisms and dosimetry

    Science.gov (United States)

    Woodhams, Josephine Helen

    Photodynamic therapy (PDT) is a treatment for a range of malignant and benign lesions using light activated photosensitising drugs in the presence of molecular oxygen. PDT causes tissue damage by a combination of processes involving the production of reactive oxygen species (in particular singlet oxygen). Since the PDT cytotoxic effect depends on oxygen, monitoring of tissue oxygenation during PDT is important for understanding the basic physiological mechanisms and dosimetry of PDT. This thesis describes the use of non-invasive, optical techniques based on visible light reflectance spectroscopy for the measurement of oxy- to deoxyhaemoglobin ratio or haemoglobin oxygen saturation (HbSat). HbSat was monitored at tissue sites receiving different light dose during aluminium disulphonated phthalocyanine (AIS2PC) PDT. Results are presented on real time PDT-induced changes in HbSat in normal tissue (rat liver) and experimental tumours, and its correlation with the final biological effect under different light regimes, including fractionated light delivery. It was found to some extent that changes in HbSat could indicate whether the tissue would be necrotic after PDT and it was concluded that online physiological dosimetry is feasible for PDT. The evaluation of a new photosensitiser for PDT called palladium-bacteriopheophorbide (WST09) has been carried out in normal and tumour tissue in vivo. WST09 was found to exert a strong PDT effect but was active only shortly after administration. WST09 produced substantial necrosis in colonic tumours whilst only causing a small amount of damage to the normal colon under certain conditions indicating a degree of selectivity. Combination therapy with PDT for enhancing the extent of PDT-induced damage has been investigated in vivo by using the photochemical internalisation (PCI) technique and Type 1 mechanism enhanced phototoxicity with indole acetic acid (IAA). PCI of gelonin using AIS2PC PDT in vivo after systemic administration of

  1. ESR/alanine dosimetry: Study of the kinetics of free radical formation. Evaluation of its contribution to the evolution of the signal after irradiation

    International Nuclear Information System (INIS)

    Dolo, J.M.; Feaugas, V.; Hourdin, L.

    1999-01-01

    CH 3 C HCOOH is commonly accepted as the free radical responsible for the ESR signal detected in alanine after irradiation. The aim of this study is to find out the number of transient species leading to this radical and their kinetics of reaction. To do so, we follow the evolution of the ESR/alanine spectrum shape and correlate the response estimated from the central peak height to the absorbed dose. We use the theory of transformation systems. The first step is to make hypothesis on the number of equivalence classes and their content. From these hypotheses, we model the kinetics of free radical concentrations and check their fitting with experiment. We present comments on these different models, and their consequences on the evolution of the ESR signal on the first days after irradiation. The two successive reaction mechanisms (creation of free radicals and recombination reaction) are compared with the results obtained from a multiparametric study (experimental design) of combined effects (temperature and humidity before and after irradiation) which influence the reaction kinetics. (author)

  2. Dosimetric characterization of two radium sources for retrospective dosimetry studies

    Energy Technology Data Exchange (ETDEWEB)

    Candela-Juan, C., E-mail: ccanjuan@gmail.com [Radiation Oncology Department, La Fe University and Polytechnic Hospital, Valencia 46026, Spain and Department of Atomic, Molecular and Nuclear Physics, University of Valencia, Burjassot 46100 (Spain); Karlsson, M. [Division of Radiological Sciences, Department of Medical and Health Sciences, Linköping University, Linköping SE 581 85 (Sweden); Lundell, M. [Department of Medical Physics and Oncology, Karolinska University Hospital and Karolinska Institute, Stockholm SE 171 76 (Sweden); Ballester, F. [Department of Atomic, Molecular and Nuclear Physics, University of Valencia, Burjassot 46100 (Spain); Tedgren, Å. Carlsson [Division of Radiological Sciences, Department of Medical and Health Sciences, Linköping University, Linköping SE 581 85, Sweden and Swedish Radiation Safety Authority, Stockholm SE 171 16 (Sweden)

    2015-05-15

    Purpose: During the first part of the 20th century, {sup 226}Ra was the most used radionuclide for brachytherapy. Retrospective accurate dosimetry, coupled with patient follow up, is important for advancing knowledge on long-term radiation effects. The purpose of this work was to dosimetrically characterize two {sup 226}Ra sources, commonly used in Sweden during the first half of the 20th century, for retrospective dose–effect studies. Methods: An 8 mg {sup 226}Ra tube and a 10 mg {sup 226}Ra needle, used at Radiumhemmet (Karolinska University Hospital, Stockholm, Sweden), from 1925 to the 1960s, were modeled in two independent Monte Carlo (MC) radiation transport codes: GEANT4 and MCNP5. Absorbed dose and collision kerma around the two sources were obtained, from which the TG-43 parameters were derived for the secular equilibrium state. Furthermore, results from this dosimetric formalism were compared with results from a MC simulation with a superficial mould constituted by five needles inside a glass casing, placed over a water phantom, trying to mimic a typical clinical setup. Calculated absorbed doses using the TG-43 formalism were also compared with previously reported measurements and calculations based on the Sievert integral. Finally, the dose rate at large distances from a {sup 226}Ra point-like-source placed in the center of 1 m radius water sphere was calculated with GEANT4. Results: TG-43 parameters [including g{sub L}(r), F(r, θ), Λ, and s{sub K}] have been uploaded in spreadsheets as additional material, and the fitting parameters of a mathematical curve that provides the dose rate between 10 and 60 cm from the source have been provided. Results from TG-43 formalism are consistent within the treatment volume with those of a MC simulation of a typical clinical scenario. Comparisons with reported measurements made with thermoluminescent dosimeters show differences up to 13% along the transverse axis of the radium needle. It has been estimated that

  3. Studies of the properties of some saccharides for lyoluminescence dosimetry

    International Nuclear Information System (INIS)

    Hazin, C.A.

    1983-03-01

    Alternative dosimetric methods for high doses are under investigation in a number of research centres. Dosemeters based on the phenomenon of lyoluminescence, i.e., emission of light following dissolution of irradiated organic and inorganic compounds were proposed in the 70's. In the present work, the response of several saccharides submitted to the radiation from a 60 Co source was studied. In order to carry out the study, a measuring system consisting of a light detection chamber and an electrometric unit was designed and built. Thereafter, studies concerning the change in light yield as a function of dose were carried out. Other investigated factors were the change in light yield with solvent pH and temperature and the stability of the response for long term storage. The results showed that maltose, lactose and glucose behaved properly as dosimetric materials for high dose measurements. Besides, no significant changes in the lyoluminescent response ocurred when the solvent pH and temperature varied around the usual values. These results show that the control of these parameters is not critica for the utilization of the saccharides under study for dosimetry. (Author) [pt

  4. In vivo thermoluminescent dosimetry in studies of helicoid computed tomography and excretory urogram

    International Nuclear Information System (INIS)

    Cruz C, D.; Azorin N, J.; Saucedo A, V.M.; Barajas O, J.L.

    2005-01-01

    The dosimetry is the field of measurement of the ionizing radiations. It final objective is to determine the 'absorbed dose' for people. The dosimetry is vital in the radiotherapy, the radiological protection and the treatment technologies by irradiation. Presently work, we develop 'In vivo' dosimetry, in exposed patients to studies of helical computed tomography and excretory urogram. The dosimetry 'in vivo' was carried out in 20 patients selected aleatorily, for each medical study. The absorbed dose was measured in points of interest located in crystalline, thyroid, chest and abdomen of each patient, by means of thermoluminescent dosemeters (TLD) LiF: Mg,Cu,P + Ptfe of national fabrication. Also it was quantified the dose in the working area. (Author)

  5. Retrospective dosimetry using unheated quartz: A feasibility study

    DEFF Research Database (Denmark)

    Thomsen, Kristina Jørkov; Bøtter-Jensen, L.; Murray, A.S.

    2002-01-01

    Most attempts to apply retrospective dosimetry to building materials have made use of heated (sensitised) items such as brick or tile ceramic. Unfired materials, such as concrete, are far more widespread in the industrial environment, but unfortunately these cannot be assumed to contain a negligi......Most attempts to apply retrospective dosimetry to building materials have made use of heated (sensitised) items such as brick or tile ceramic. Unfired materials, such as concrete, are far more widespread in the industrial environment, but unfortunately these cannot be assumed to contain...... poorly zeroed building materials can provide useful information on accident doses....

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1986-06-01

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

  7. A preliminary study before active personnel dosimetry setup at the CRLCC Rene Gauducheau

    International Nuclear Information System (INIS)

    Lisbona, A.; Lemperiere, F.

    2002-01-01

    French regulations for implementation of active personnel dosimetry leads the radiation protection adviser to conduct a reflection before its complex practical application in an hospital. The main goal of this study is to estimate the real exposition level by situation in order to associate effective dose levels. The objective grading of the employees is obtained in accordance with the occupational physician and in relation with the real exposition level at which these employees are exposed during their standard workload. At the beginning of the study, the situation is: 170 employees graded as so called A category, for whom the results of the mandatory passive dosimetry (film) give effective dose values under the threshold or very low. We also have the results of active dosimetry since 1997 for the technologists working in the Nuclear Medicine department. An inquiry is conducted to define, for the 170 employees, all the encountered situations as well as the conditions (time, mean distance, tasks frequencies) in order to estimate by calculation, or by measuring the effective dose in relation with different situations. By analysing the obtained data it is possible to propose: a data base for the description of all the situations (Microsoft Access); grading of 161 employees as B category with quarterly subscription for film dosimetry and 9 employees as A category; 28 electronic dosemeters for active dosimetry; new areas for controlled and supervised areas. By using a methodology based on objective data and communication it is possible to propose for an hospital a realistic organisation for active personnel dosimetry. (author)

  8. Evaluation of selected predictive models and parameters for the environmental transport and dosimetry of radionuclides

    International Nuclear Information System (INIS)

    Miller, C.W.; Dunning, D.E. Jr.; Etnier, E.L.; Hoffman, F.O.; Little, C.A.; Meyer, H.R.; Shaeffer, D.L.; Till, J.E.

    1979-07-01

    Evaluations of selected predictive models and parameters used in the assessment of the environmental transport and dosimetry of radionuclides are summarized. Mator sections of this report include a validation of the Gaussian plume disperson model, comparison of the output of a model for the transport of 131 I from vegetation to milk with field data, validation of a model for the fraction of aerosols intercepted by vegetation, an evaluation of dose conversion factors for 232 Th, an evaluation of considering the effect of age dependency on population dose estimates, and a summary of validation results for hydrologic transport models

  9. Evaluation of selected predictive models and parameters for the environmental transport and dosimetry of radionuclides

    Energy Technology Data Exchange (ETDEWEB)

    Miller, C.W.; Dunning, D.E. Jr.; Etnier, E.L.; Hoffman, F.O.; Little, C.A.; Meyer, H.R.; Shaeffer, D.L.; Till, J.E.

    1979-07-01

    Evaluations of selected predictive models and parameters used in the assessment of the environmental transport and dosimetry of radionuclides are summarized. Mator sections of this report include a validation of the Gaussian plume disperson model, comparison of the output of a model for the transport of /sup 131/I from vegetation to milk with field data, validation of a model for the fraction of aerosols intercepted by vegetation, an evaluation of dose conversion factors for /sup 232/Th, an evaluation of considering the effect of age dependency on population dose estimates, and a summary of validation results for hydrologic transport models.

  10. High-accuracy dosimetry study for intensity-modulated radiation therapy(IMRT) commissioning

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Hae Sun

    2010-02-15

    Intensity-modulated radiation therapy (IMRT), an advanced modality of high-precision radiotherapy, allows for an increase in dose to the tumor volume without increasing the dose to nearby critical organs. In order to successfully achieve the treatment, intensive dosimetry with accurate dose verification is necessary. A dosimetry for IMRT, however, is a challenging task due to dosimetric ally unfavorable phenomena such as dramatic changes of the dose at the field boundaries, dis-equilibrium of the electrons, non-uniformity between the detector and the phantom materials, and distortion of scanner-read doses. In the present study, therefore, the LEGO-type multi-purpose dosimetry phantom was developed and used for the studies on dose measurements and correction. Phantom materials for muscle, fat, bone, and lung tissue were selected after considering mass density, atomic composition, effective atomic number, and photon interaction coefficients. The phantom also includes dosimeter holders for several different types of detectors including films, which accommodates a construction of different designs of phantoms as necessary. In order to evaluate its performance, the developed phantom was tested by measuring the point dose and the percent depth dose (PDD) for small size fields under several heterogeneous conditions. However, the measurements with the two types of dosimeter did not agree well for the field sizes less than 1 x 1 cm{sup 2} in muscle and bone, and less than 3 x 3 cm{sup 2} in air cavity. Thus, it was recognized that several studies on small fields dosimetry and correction methods for the calculation with a PMCEPT code are needed. The under-estimated values from the ion chamber were corrected with a convolution method employed to eliminate the volume effect of the chamber. As a result, the discrepancies between the EBT film and the ion chamber measurements were significantly decreased, from 14% to 1% (1 x 1 cm{sup 2}), 10% to 1% (0.7 x 0.7 cm{sup 2}), and 42

  11. Evaluation of the Gafchromic® EBT2 film for the dosimetry of radiosurgical beams

    International Nuclear Information System (INIS)

    Lárraga-Gutiérrez, José M.; García-Hernández, Diana; García-Garduño, Olivia A.; Galván de la Cruz, Olga O.; Ballesteros-Zebadúa, Paola; Esparza-Moreno, Karina P.

    2012-01-01

    Purpose: Radiosurgery uses small fields and high-radiation doses to treat intra- and extracranial lesions in a single session. The lack of a lateral electronic equilibrium and the presence of high-dose gradients in these fields are challenges for adequate measurements. The availability of radiation detectors with the high spatial resolution required is restricted to only a few. Stereotactic diodes and EBT radiochromic films have been demonstrated to be good detectors for small-beam dosimetry. Because the stereotactic diode is the standard measurement for the dosimetry of radiosurgical beams, the goal of this work was to perform measurements with the radiochromic film Gafchromic ® EBT2 and compare its results with a stereotactic diode. Methods: Total scatter factors, tissue maximum, and off-axis ratios from a 6 MV small photon beams were measured using EBT2 radiochromic film in a water phantom. The film-measured data were evaluated by comparing it with the data measured with a stereotactic field diode (IBA-Dosimetry). Results: The film and diode measurements had excellent agreement. The differences between the detectors were less than or equal to 2.0% for the tissue maximum and the off-axis ratios. However, for the total scatter factors, there were significant differences, up to 4.9% (relative to the reference field), for field sizes less than 1.0 cm. Conclusions: This work found that the Gafchromic ® EBT2 film is adequate for small photon beam measurements, particularly for tissue maximum and off-axis ratios. However, careful attention must be taken when measuring output factors of small beams below 1.0 cm due to the film's energy dependence. The measurement differences may be attributable to the film's active layer composition because EBT2 incorporates higher Z elements (i.e., bromide and potassium), hence revealing a potential energy dependence for the dosimetry of small photon beams.

  12. [Evaluation of transit in vivo dosimetry using portal imaging and comparison with measurements using diodes].

    Science.gov (United States)

    Royer, P; Marchesi, V; Rousseau, V; Buchheit, I; Wolf, D; Peiffert, D; Noël, A

    2014-06-01

    In vivo dosimetry transit using portal imaging is a promising approach for quality assurance in radiotherapy. A comparative evaluation was conducted between a commercial solution, EPIgray(®) and an in vivo dosimetry control reference using semiconductors diodes. The performance of the two in vivo dosimetry methods was assessed. The primary endpoint was the dose deviation between the reconstructed dose at the prescription point and the measured dose using the ionization chamber in phantoms or the calculated predictive dose by the treatment planning system with patients. The deviation threshold was set to ±5%. In total, 107 patients were prospectively included and treated with 3D-conformal radiotherapy (3D-CRT) or intensity-modulated radiotherapy (IMRT) techniques for tumours of the brain, chest and head and neck. The dosimetric accuracy of EPIgray(®) in phantom were comparable to diodes in terms of repeatability (0.11%), reproducibility (0.29-0.51%) with a mean dose deviation of 0.17% (SD: 1.11). The rates of radiotherapy sessions out of the tolerance for the brain (3D-CRT and IMRT), thorax (3D-CRT) and the head and neck (IMRT) were respectively 0%, 9.6% and 5.3% with a mean dose deviation ranging between 0.49% and 1.53%. The mean of dose deviation between three consecutive sessions with EPIgray(®) validates 99.1% of treatments. The performance of EPIgray(®) in in vivo dosimetry is consistent with the recommendations of the European Society for Radiotherapy and Oncology (ESTRO) and equivalent to semiconductor diodes for 3D-CRT. It also allows adequate control for IMRT, which is technically difficult to perform with the diodes. Copyright © 2014 Société française de radiothérapie oncologique (SFRO). Published by Elsevier SAS. All rights reserved.

  13. Pre-evaluation of an ionization chamber for clinical radiotherapy dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Neves, Lucio P.; Perini, Ana P.; Xavier, Marcos; Caldas, Linda V.E., E-mail: mxavier@ipen.b, E-mail: lcaldas@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Khoury, Helen J., E-mail: khoury@ufpe.b [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Dept. de Energia Nuclear

    2011-07-01

    This work presents some pre-operational tests for characterization of a new homemade ionization chamber developed at the Calibration Laboratory of Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP). This chamber was designed for use in radiotherapy dosimetry. To study the utilization of this chamber in radiotherapy, some tests were undertaken: short- and medium-term stabilities, saturation curve, recombination loss, polarity effect and leakage current. All results obtained in these tests were within the international recommendations. (author)

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

    Energy Technology Data Exchange (ETDEWEB)

    Heintz, P; Chambers, G; Sandoval, D [University of New Mexico, Albuquerque, NM (United States)

    2014-06-01

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

  15. MATLAB platform for Monte Carlo planning and dosimetry experimental evaluation

    International Nuclear Information System (INIS)

    Baeza, J. A.; Ureba, A.; Jimenez-Ortega, E.; Pereira-Barbeiro, A. R.; Leal, A.

    2013-01-01

    A new platform for the full Monte Carlo planning and an independent experimental evaluation that it can be integrated into clinical practice. The tool has proved its usefulness and efficiency and now forms part of the flow of work of our research group, the tool used for the generation of results, which are to be suitably revised and are being published. This software is an effort of integration of numerous algorithms of image processing, along with planning optimization algorithms, allowing the process of MCTP planning from a single interface. In addition, becomes a flexible and accurate tool for the evaluation of experimental dosimetric data for the quality control of actual treatments. (Author)

  16. Study of thermoluminescence and semiconductors in dosimetry. Application of dosimetry of the whole body in view of bone marrow grafting

    International Nuclear Information System (INIS)

    Naudy, Suzanne.

    1981-05-01

    From this study one deduces that thermoluminescence remains the moss reliable process for the measurement of dose in vivo: precision, reproducibility and easy calibration. The semiconductors do not present the quality needed to a reliable use in dosimetry. The limits of each techniques have been established in our study, we have applied them simultaneously in dosimetric irradiations of the whole body in view of bone marrow grafting. Semiconductors allow to follow the irradiation and to intervene instantaneously if necessary, thermoluminescent dosimeter insure precise knowledge of the delivered dose. One hundred and ten patients have been treated before bone narrow grafting at the Gustave Roussy Institut and fifty two of them render account of the results obtained with this experimental dosimetric protocol [fr

  17. Absorbed dose evaluations in retrospective dosimetry: Methodological developments using quartz

    DEFF Research Database (Denmark)

    Bailiff, I.K.; Bøtter-Jensen, L.; Correcher, V.

    2000-01-01

    -300 mGy were obtained using TL (210 degreesC TL and pre-dose) and OSL (single and multiple aliquot) procedures. Overall, good inter-laboratory concordance of dose evaluations was achieved, with a variance (1 sigma) of similar to+/-10 mGy for the samples examined. (C) 2000 Elsevier Science Ltd. All...

  18. The Impact of Iterative Reconstruction on Computed Tomography Radiation Dosimetry: Evaluation in a Routine Clinical Setting

    Science.gov (United States)

    Moorin, Rachael E.; Gibson, David A. J.; Forsyth, Rene K.; Fox, Richard

    2015-01-01

    Purpose To evaluate the effect of introduction of iterative reconstruction as a mandated software upgrade on radiation dosimetry in routine clinical practice over a range of computed tomography examinations. Methods Random samples of scanning data were extracted from a centralised Picture Archiving Communication System pertaining to 10 commonly performed computed tomography examination types undertaken at two hospitals in Western Australia, before and after the introduction of iterative reconstruction. Changes in the mean dose length product and effective dose were evaluated along with estimations of associated changes to annual cancer incidence. Results We observed statistically significant reductions in the effective radiation dose for head computed tomography (22–27%) consistent with those reported in the literature. In contrast the reductions observed for non-contrast chest (37–47%); chest pulmonary embolism study (28%), chest/abdominal/pelvic study (16%) and thoracic spine (39%) computed tomography. Statistically significant reductions in radiation dose were not identified in angiographic computed tomography. Dose reductions translated to substantial lowering of the lifetime attributable risk, especially for younger females, and estimated numbers of incident cancers. Conclusion Reduction of CT dose is a priority Iterative reconstruction algorithms have the potential to significantly assist with dose reduction across a range of protocols. However, this reduction in dose is achieved via reductions in image noise. Fully realising the potential dose reduction of iterative reconstruction requires the adjustment of image factors and forgoing the noise reduction potential of the iterative algorithm. Our study has demonstrated a reduction in radiation dose for some scanning protocols, but not to the extent experimental studies had previously shown or in all protocols expected, raising questions about the extent to which iterative reconstruction achieves dose

  19. Technical requirements for implementation of an individual monitoring service for evaluation of operational quantity HP(10) using thermoluminescent dosimetry

    International Nuclear Information System (INIS)

    Francisco, Adelaide Benedita Armando

    2016-01-01

    This work aims to establish technical requirements for the development of a TLDs system for the assessment of operational quantity H P (10), in order to implement an external individual monitoring service in countries who do not have. This allows a better understanding of the technic and the thermoluminescent dosimetry system, thus contributing to identify the technical criteria to be followed by a dosimetry laboratory and evaluation of the dosimetric system performance. For this, the review of the specific literature of the dosimetry field was conducted and later the type and performance tests that must be followed by a dosimetric system were reproduced in practice. In additional was made a analysis of internationals standards norms and the technical regulation used in Brazil, to define the essentials type testes to a dosimetric system. To check the performance of a dosimetry system, a performance analysis of the Brazilian TLDs system was carried out over the past 6 years using the trumpet curve, where it was observed that most of TLDs system, in this review period, were approved and have excellent performance. The technical requirements for the development of a thermoluminescent dosimetry system ensure that the system provides technically reliable results and allow demonstration of compliance with the standard criteria established by national and international standards, and the implementation of the dosimetry system, is verified the compliance of the annual doses limits set for occupationally exposed. (author)

  20. A molding technique for use in internal dosimetry studies

    International Nuclear Information System (INIS)

    Aissi, A.; Tsakeres, F.S.; Poston, J.W.

    1982-01-01

    A method is described for producing molds which can be used in the construction of volumetric organ dosimeters. These negative organ molds are formed by wrapping quick-setting plaster bandages around a silicon-treated hardwood organ mold. The cast is cut in two and after further setting time is ready to contain the tissue equivalent materials and thermoluminescent powders. Such volumetric dosimeters will be useful for comparing experimental and calculated internal dosimetry results. (U.K.)

  1. Magnetic Fluid Hyperthermia for Bladder Cancer: A Preclinical Dosimetry Study

    Science.gov (United States)

    Oliveira, Tiago R.; Stauffer, Paul R.; Lee, Chen-Ting; Landon, Chelsea D.; Etienne, Wiguins; Ashcraft, Kathleen A.; McNerny, Katie L.; Mashal, Alireza; Nouls, John; Maccarini, Paolo F.; Beyer, Wayne F.; Inman, Brant; Dewhirst, Mark W.

    2014-01-01

    Purpose This paper describes a preclinical investigation of the feasibility of thermotherapy treatment of bladder cancer with Magnetic Fluid Hyperthermia (MFH), performed by analyzing the thermal dosimetry of nanoparticle heating in a rat bladder model. Materials and Methods The bladders of twenty-five female rats were instilled with magnetite-based nanoparticles, and hyperthermia was induced using a novel small animal magnetic field applicator (Actium Biosystems, Boulder, CO). We aimed to increase the bladder lumen temperature to 42°C in <10 min and maintain that temperature for 60 min. Temperatures were measured within the bladder lumen and throughout the rat with seven fiberoptic probes (OpSens Technologies, Quebec, Canada). An MRI analysis was used to confirm the effectiveness of the catheterization method to deliver and maintain various nanoparticle volumes within the bladder. Thermal dosimetry measurements recorded the temperature rise of rat tissues for a variety of nanoparticle exposure conditions. Results Thermal dosimetry data demonstrated our ability to raise and control the temperature of rat bladder lumen ≥1°C/min to a steady-state of 42°C with minimal heating of surrounding normal tissues. MRI scans confirmed the homogenous nanoparticle distribution throughout the bladder. Conclusion These data demonstrate that our MFH system with magnetite-based nanoparticles provide well-localized heating of rat bladder lumen with effective control of temperature in the bladder and minimal heating of surrounding tissues. PMID:24050253

  2. Implementation and evaluation of a transit dosimetry system for treatment verification.

    Science.gov (United States)

    Ricketts, K; Navarro, C; Lane, K; Moran, M; Blowfield, C; Kaur, U; Cotten, G; Tomala, D; Lord, C; Jones, J; Adeyemi, A

    2016-05-01

    To evaluate a formalism for transit dosimetry using a phantom study and prospectively evaluate the protocol on a patient population undergoing 3D conformal radiotherapy. Amorphous silicon EPIDs were calibrated for dose and used to acquire images of delivered fields. The measured EPID dose map was back-projected using the planning CT images to calculate dose at pre-specified points within the patient using commercially available software, EPIgray (DOSIsoft, France). This software compared computed back-projected dose with treatment planning system dose. A series of tests were performed on solid water phantoms (linearity, field size effects, off-axis effects). 37 patients were enrolled in the prospective study. The EPID dose response was stable and linear with dose. For all tested field sizes the agreement was good between EPID-derived and treatment planning system dose in the central axis, with performance stability up to a measured depth of 18cm (agreement within -0.5% at 10cm depth on the central axis and within -1.4% at 2cm off-axis). 126 transit images were analysed of 37 3D-conformal patients. Patient results demonstrated the potential of EPIgray with 91% of all delivered fields achieved the initial set tolerance level of ΔD of 0±5-cGy or %ΔD of 0±5%. The in vivo dose verification method was simple to implement, with very few commissioning measurements needed. The system required no extra dose to the patient, and importantly was able to detect patient position errors that impacted on dose delivery in two of cases. Copyright © 2016 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

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

    Energy Technology Data Exchange (ETDEWEB)

    None

    2013-06-06

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

  4. Fifteenth nuclear accident dosimetry intercomparison study: August 14--22, 1978

    International Nuclear Information System (INIS)

    Sims, C.S.

    1979-05-01

    The fifteenth in the continuing series of Nuclear Accident Dosimetry Intercomparison Studies was held August 14--22, 1978 at the Oak Ridge National Laboratory. The Health Physics Research Reactor, operated in the pulse mode, served as the radiation source. Using different shielding configurations, nuclear accidents with three different neutron and gamma spectra were simulated. Participants from 19 organizations, the most in the history of the studies, exposed dosimeters set up as area monitors as well as dosimeters mounted on phantoms for personnel monitoring. Although many participants performed accurate measurements, the composite dose results, in the majority of cases, failed to meet established nuclear criticality accident dosimetry guidelines which suggest accuracies of +- 25% for neutron dose and +- 20% for gamma dose. This indicates that many participants need to improve their dosimetry systems, their analytical techniques, or both

  5. Influence of Paraiba uranium deposit in the evaluation of radioecological dosimetry from Sao Mamede- PB

    International Nuclear Information System (INIS)

    Damascena, Kennedy Francys Rodrigues; Santos Junior, Jose Araujo; Charfuelan, Juana Maria Jimenez; Amaral, Romilton dos Santos; Silva, Alberto Antonio da; Santos, Josineide Marques do Nascimento; Fernandez, Zahily Herrero; Maciel Neto, Jose de Almeida

    2015-01-01

    Regions with different levels of natural radionuclides should be investigated from the radioecological viewpoint, to establish protection criteria for environment and the population. The municipality of São Mamede in the state of Paraiba, is one of the closest of the uranium deposit in Espinharas - PB, and can be influenced, given its geological formation, which justifies conducting environmental dosimetric studies. The United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) established in 2008 a value for the environmental equivalent effective dose rate of 2.44 mSv / y, considering the different forms of exposure and outdoor environments and internal. The calculation for estimating the outdoor dose rate considered a factor of 0.2, which corresponds therefore to a dose rate of 0.46 mSv / y for these environments. The objective of this study was to determine the levels of natural ionizing radiation that municipality using estimated effective dose rate measured in air and 1.0 m from the surface, points to the presence of rocky outcrops using portable detector with discriminator combined probe of NaI (Tl) and BGO. The experimental setup allowed the evaluation of eighty-one points, dose rates ranged from 0.34 to 4.0 mSv / y, with an average of 0.76 mSv / y, exceeding the global average by a factor of 9, which characterizes the need to investigate the dosimetry for internal environments, which can define criteria to check a possible estimate of radioecological risk. (author)

  6. A novel dosimetry system for computed tomography using phototransistor

    International Nuclear Information System (INIS)

    Magalhães, C.M.S.; Sobrinho, M.L.; Souza, D.N.; Filho, J. Antônio; Silva, E.F. da; Santos, L.A.P.

    2012-01-01

    Computed tomography (CT) dosimetry normally uses an ionization chamber 100 mm long to estimate the computed tomography dose index (CTDI), however some reports have already indicated that small devices could replace the long ion chamber to improve quality assurance procedures in CT dosimetry. This paper presents a novel dosimetry system based in a commercial phototransistor evaluated for CT dosimetry. Three detector configurations were developed for this system: with a single, two and four devices. Dose profile measurements were obtained with them and their angular responses were evaluated. The results showed that the novel dosimetry system with the phototransistor could be an alternative for CT dosimetry. It allows to obtain the CT dose profile in details and also to estimate the CTDI in longer length than the 100 mm pencil chamber. The angular response showed that the one device detector configuration is the most adequate among the three configurations analyzed in this study.

  7. Evaluation of the vidar`s VXR-12 digitizer performances for film dosimetry of beams delimited by multileaf collimator

    Energy Technology Data Exchange (ETDEWEB)

    Julia, F. [Centre de Lutte Contre le Cancer Gustave-Roussy, 94 - Villejuif (France); Briot, E.

    1995-12-01

    The development of new irradiation techniques such as conformal radiotherapy increasingly implies the use of a multileaf collimator. The measurement of dose gradients in the penumbra region, and of dose distributions at the edge of complex shaped fields defined by multileaf collimators requires a high definition dosimetric method. Nowadays film digitizers have been notably improved and allow the film dosimetry to be faster, more accurate, presenting a sensitivity and high spatial resolution. To be able to perform the study of physical and dosimetric specifications of a multileaf collimator, we have evaluated the performances of the Vidar VCR-12 digitizer, with respect to its sensitivity, linearity, optical density range and the resolution. These performances were compared with the performances of different systems already in use in our department, either manual or automatic, using specific patterns. The main limitation for dosimetric use is the detection threshold that can introduce errors in isodose calculation, especially for the lowest values. The result of the intercomparisons have allowed corrections to be added, taking into account this Vidar problem. The results obtained after correction for the dose profiles of squared fields are in good agreement with ionization chamber measurements in a water phantom. It is concluded that Vidar digitizer is suitable for the use of film dosimetry for the dose distributions in fields defined by multileaf collimator.

  8. Oak Ridge National Laboratory Embrittlement Data Base (EDB) and Dosimetry Evaluation (DE) program

    International Nuclear Information System (INIS)

    Pace, J.V. III; Remec, I.; Wang, J.A.; White, J.E.

    1996-01-01

    The objective of this program is to develop, maintain, and upgrade computerized data bases, calculational procedures, and standards relating to reactor pressure vessel fluence spectra determinations and embrittlement assessments. As part of this program, the information from radiation embrittlement research on nuclear reactor pressure vessel steels and from power reactor surveillance reports is maintained in a data base published on a periodic basis. The Embrittlement Data Base (EDB) effort consists of verifying the quality of the EDB, providing user-friendly software to access and process the data, and exploring and assessing embrittlement prediction models. The Dosimetry Evaluation effort consists of maintaining and upgrading validated neutron and gamma radiation transport procedures, maintaining cross-section libraries with the latest evaluated nuclear data, and maintaining and updating validated dosimetry procedures and data bases. The information available from this program provides data for assisting the Office of Nuclear Reactor Regulation, with support from the Office of Nuclear Regulatory Research, to effectively monitor current procedures and data bases used by vendors, utilities, and service laboratories in the pressure vessel irradiation surveillance program

  9. Computational dosimetry and risk assessment of radioinduced cancer: studies in mammary glands radiotherapy, radiopharmaceuticals and internal contamination

    International Nuclear Information System (INIS)

    Mendes, Bruno Melo

    2017-01-01

    The use of Ionizing radiation (IR) in medicine has increased considerably. The benefits generated by diagnostic and therapy techniques with IR are proven. Nevertheless, the risks arising from these uses should not be underestimated. Justification, a basic radiation protection, states that the benefits from exposures must outweigh detriment. The cancer induction is one of the detriment components. Thus, the study of the benefit/detriment ratio should take into account cancer incidence and mortality estimations resulting from a given diagnosis or therapy radiological technique. The risk of cancer induction depends on the absorbed doses in the irradiated organs and tissues. Thus, IR dosimetry is essential to evaluate the benefit/detriment ratio. The present work aims to perform computational dosimetric evaluations and estimations of cancer induction risk after ionizing radiation exposure. The investigated situations cover nuclear medicine, radiological contamination and radiotherapy fields. Computational dosimetry, with MCNPx Monte Carlo Code, was used as a tool to calculate the absorbed dose in the interest organs of the voxelized human models. The simulations were also used to obtain calibration factors and optimization of in vivo monitoring systems for internal contamination dosimetry. A breast radiotherapy (RT) standard protocol was simulated using the MCNPx code. The calculation of the radiation-induced cancer risk was adapted from the BEIR VII methodology for the Brazilian population. The absorbed doses used in the risk calculations were obtained through computational simulations of different exposure scenarios. During this work, two new computational phantoms, DM B RA and VW, were generated from tomographic images. Additional twelve voxelized phantoms, including the reference phantoms, RCP A M and RCP A F, and the child, baby, and fetus models were adapted to run on MCNP. Internal Dosimetry Protocols (IDP) for radiopharmaceuticals and for internal contamination

  10. A multi-centre dosimetry audit on advanced radiotherapy in lung as part of the Isotoxic IMRT study

    Directory of Open Access Journals (Sweden)

    Yat Tsang

    2017-10-01

    Conclusion: This multi-centre dosimetry audit of complex IMRT/VMAT delivery provides confidence in the accuracy of modern planning and delivery systems in inhomogeneous tissues. The findings from this study can be used as a reference for future dosimetry audits.

  11. Internal sources dosimetry

    International Nuclear Information System (INIS)

    Savio, Eduardo

    1994-01-01

    The absorbed dose, need of estimation in risk evaluation in the application of radiopharmaceuticals in Nuclear Medicine practice,internal dosimetry,internal and external sources. Calculation methodology,Marinelli model,MIRD system for absorbed dose calculation based on biological parameters of radiopharmaceutical in human body or individual,energy of emitted radiations by administered radionuclide, fraction of emitted energy that is absorbed by target body.Limitation of the MIRD calculation model. A explanation of Marinelli method of dosimetry calculation,β dosimetry. Y dosimetry, effective dose, calculation in organs and tissues, examples. Bibliography .

  12. Re-evaluation of the dosimetry for reactor pressure-vessel surveillance capsules

    International Nuclear Information System (INIS)

    Simons, R.L.; Kellogg, L.S.; Lippincott, E.P.; McElroy, W.N.; Oberg, D.L.

    1982-03-01

    Revised fluences and displacements per atom (dpa) and their uncertainties were determined after re-evaluating the neutron dosimeters from forty-one pressurized water reactor (PWR) surveillance capsules. The goals of this HEDL Reactor Dosimetry Center work are (1) to apply and test new ASTM recommended physics-dosimetry analysis methods and data being developed for LWR power plant surveillance and (2) to provide improved neutron exposure values for reactor pressure vessel steel metallurgical data bases; particularly for the changes in nil ductility transition temperature (ΔNDTT) and upper shelf energy. Uncertainties in the FERRET-SAND adjustment Code derived neutron exposure values range from 10 to 34%. The ratio of the new to the old exposure values for fluence greater than 1 MeV varied from a low of 0.79 to a high of 2.11, with an average value of 1.30. The fission reactions for 238 U and 237 Np were found to be instrumental in producing low uncertainties in the exposure values (10 to 15%) whereas with their absence the uncertainty increased to 25 to 34%. Corrections for fissile impurity atoms in the 238 U dosimeters were found to be as high as 29% in some cases. Other sources of corrections such as surveillance capsule perturbations and photo fission reactions have been considered

  13. Evaluation of interobserver differences in postimplant dosimetry following prostate brachytherapy and the efficacy of CT/MRI fusion imaging

    International Nuclear Information System (INIS)

    Aoki, Manabu; Yorozu, Atsunori; Dokiya, Takushi

    2009-01-01

    Interobserver differences in postimplant dosimetry based on computed tomography (CT) and CT/magnetic resonance imaging (MRI) fusion images were assessed to evaluate the efficacy of the fusion image. In addition, the part of the prostate contour responsible for the interobserver differences in CT was identified. In June 2008, 1-month postimplant CT data from two patients who underwent 125 I prostate brachytherapy were sent to 90 institutions for postimplant dosimetry. Subsequently, MRI data from the same patients were sent for fusion-based postimplant dosimetry. The variance of the difference between MRI-based D90 and CT-based or fusion-based D90 was compared. Prostate volume on CT was plotted on the y-axis against the position of the most cranial and caudal slices in the prostate contour delineated at each institution to analyze interobserver differences. The prostate volume from CT was significantly greater than from the CT/MRI fusion image (P=0.0014). Fusion-based variance was significantly greater than CT-based variance (P<0.01). CT-based postimplant dosimetry showed that 88%-96% of the institutions had an apical and basal position within a range of 5 mm. There were marked interobserver differences in CT/MRI fusion-based postimplant dosimetry. (author)

  14. Evaluation of a new self-developing instant film for imaging and dosimetry

    International Nuclear Information System (INIS)

    Watanabe, Y.; Patel, G. N.; Patel, P.

    2006-01-01

    Radiation sensitive films are standard dosimetric tools in radiation therapy. Films are used for machine quality assurance (QA) and treatment planning software evaluation. With the advent of intensity modulated radiation therapy (IMRT), simple and fast imaging technology is needed for patient-specific verification of radiation fields. Conventional radiographic films are often used. Radiochromic films, e.g. Gafchromic films, were recently introduced to the market. But these films have some disadvantages. JP Laboratories have developed a prototype radiochromic film, called SIFID (self-developing, instant film for imaging and dosimetry) with superior performance such that SIFID is unaffected by ambient light for months, stable up to 90 deg. C and can be archived. SIFID is made of polymerizable diacetylene. The film develops blue colour instantly upon absorbing radiation. We evaluated the film for radiation therapy applications. Our preliminary data demonstrate its feasibility as a dosimetric tool for IMRT QA as well as for other applications. (authors)

  15. Neutron personnel dosimetry considerations for fusion reactors

    International Nuclear Information System (INIS)

    Barton, T.P.; Easterly, C.E.

    1979-07-01

    The increasing development of fusion reactor technology warrants an evaluation of personnel neutron dosimetry systems to aid in the concurrent development of a radiation protection program. For this reason, current state of knowledge neutron dosimeters have been reviewed with emphasis placed on practical utilization and the problems inherent in each type of dosimetry system. Evaluations of salient parameters such as energy response, latent image instability, and minimum detectable dose equivalent are presented for nuclear emulsion films, track etch techniques, albedo and other thermoluminescent dosimetry techniques, electrical conductivity damage effects, lyoluminescence, thermocurrent, and thermally stimulated exoelectron emission. Brief summaries of dosimetry regulatory requirements and intercomparison study results help to establish compliance and recent trends, respectively. Spectrum modeling data generated by the Neutron Physics Division of Oak Ridge National Laboratory for the Princeton Tokamak Fusion Test Reactor (TFTR) Facility have been analyzed by both International Commission on Radiological Protection fluence to dose conversion factors and an adjoint technique of radiation dosimetry, in an attempt to determine the applicability of current neutron dosimetry systems to deuterium and tritium fusion reactor leakage spectra. Based on the modeling data, a wide range of neutron energies will probably be present in the leakage spectra of the TFTR facility, and no appreciable risk of somatic injury to occupationally exposed workers is expected. The relative dose contributions due to high energy and thermal neutrons indicate that neutron dosimetry will probably not be a serious limitation in the development of fusion power

  16. A study of computational dosimetry and boron biodistribution for ex – situ lung BNCT at RA-3 Reactor

    International Nuclear Information System (INIS)

    Garabalino, M.A.; Trivillin, V. A.; Monti Hughes, A.; Pozzi, E.C.C.; Thorp, S.; Curotto, P; Miller, M.; Santa Cruz, G.A.; Saint Martin, G.; Schwint, A.E.; González, S.J.; Farías, R.O; Portu, A.; Ferraris, S.; Santa María, J.; Lange, F.; Bortolussi, S.; Altieri, S.

    2013-01-01

    Within the context of the preclinical ex-situ BNCT Project for the treatment of diffuse lung metastases, we performed boron biodistribution studies in a sheep model and computational dosimetry studies in human lung to evaluate the potential therapeutic efficacy of the proposed technique. Herein we report preliminary data that supports the use of the sheep model as an adequate human surrogate in terms of boron kinetics and uptake in clinically relevant tissues. Furthermore, the estimation of the potential therapeutic efficacy of the proposed treatment in humans, based on boron uptake values in the large animal model, yields promising tumor control probability values even in the most conservative scenario considered. (author)

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

    Energy Technology Data Exchange (ETDEWEB)

    Akino, Yuichi; Das, Indra J.; Bartlett, Gregory K.; Zhang Hualin; Thompson, Elizabeth; Zook, Jennifer E. [Department of Radiation Oncology, Indiana University School of Medicine, Indianapolis, Indiana 46202 (United States) and Department of Radiation Oncology, Osaka University Graduate School of Medicine, Suita, Osaka 565-0871 (Japan); Department of Radiation Oncology, Indiana University School of Medicine, Indianapolis, Indiana 46202 (United States)

    2013-01-15

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

  18. Study on dosimetry for child in dentistry, 2. Examination survey on radiation dosimetry by various technique

    Energy Technology Data Exchange (ETDEWEB)

    Tateno, H.; Itoh, T.; Higaki, M.; Kanno, M.; Higashi, T. (Kanagawa Dental Coll., Yokosuka (Japan))

    1981-12-01

    Recently, we used X-ray inspection very frequently and take an X-ray picture by various techniques in dental diagnosis. Patients in pedodontics usually do not appeal appropriately the symptom of their own disease because of their immaturness. For this reason, X-ray inspection plays a big part in diagnosis. Since the exposure dose became a social problem, it is necessary to pay consideration to X-ray technique for children because of higher sensitivity than adults. But studies of the exposure dose are reported in medical field and few of them are about pedodontics. Therefore, distribution of exposure dose in the 6-film technique (intraoral technique) for children was surveyed by use of water phantom examining the reliability of TLD, the defect of scattered rays and indicator dependence etc. were tested in part. 1. But the first report is two dimensional, so we examined the 6-films technique, the body view of mandible, the orthopantomography and the cephalography for Mix-DP (for child). The following results were obtained. 1. The 6-film technique showed the highest exposure dose at skin, eye and thyroid gland. 2. The exposure dose at thyroid gland by 6-film technique was 0.734 R. 3. The exposure dose at gonad was less 0.001 R. by all techniques. 4. The exposure dose to the child tended to be higher than to the adult by all techniques.

  19. SU-E-T-609: Evaluation of Transit Dosimetry Software Using Heterogeneous Phantom

    Energy Technology Data Exchange (ETDEWEB)

    Matulewicz, L; Prazmowska, J; Stapor-Fudzinska, M; Slosarek, K [Maria Sklodowska-Curie Memorial Cancer Center and Institute of Oncology, Gliwice (Poland)

    2014-06-01

    Purpose: The purpose of this work was to evaluate limits and capabilities in the transit dosimetry software for use with the TomoTherapy system by irradiating a heterogeneous phantom. Methods: Helical TomoTherapy plan was created using CIRS phantom (model 062M) with nine various tissue equivalent inserts (lung inhale 0.2 g/cm{sup 3}, lung exhale 0.5 g/cm{sup 3}, adipose 0.96 g/cm{sup 3}, breast 0.99 g/cm{sup 3}, water 1.01 g/cm{sup 3}, muscle 1.06 g/cm{sup 3}, liver 1.07 g/cm{sup 3}, trabecular bone 1.16 g/cm{sup 3}, and dense bone 1.53 g/cm{sup 3}). Targets were contoured within every insert. The phantom was scanned with a 50 cm field of view and 3 mm slice width. Images were imported into the TomoTherapy TPS. A plan was generated to deliver 20 Gy to every insert (2 Gy per fraction) with a jaw width of 2.5 cm, a pitch of 0.430 and an actual modulation factor of 2.621. After the radiation delivery the planning CT, the RT structure, the RT plan, and the RT dose (DICOM format) as well as the exit detector sinogram were imported into the Dosimetry Check software (Math Resolutions, LLC). The 3D delivered doses were reconstructed from the exit detector data by correcting for phantom and couch attenuation. The resulting dose distribution were compared with the TPS planned dose using gamma index. Results: Using the clinical gamma criteria, 3% and 3 mm, all tissue equivalent inserts had a passing percentage of 100% except for 0.2 g/cm{sup 3} and 0.5 g/cm{sup 3} density inserts (gamma value of 81.67% and 99.18% respectively). Conclusion: The evaluated transit dosimetry software provides an independent verification of helical TomoTherapy plans giving additional confidence in the treatment delivery, however, an overestimation of the reconstructed dose in low density materials has been revealed. Implementation of Monte Carlo algorithm for exit dose reconstruction should improve dosimetric accuracy in heterogeneous patient tissues. Agreement with Math Resolutions.

  20. Comparison and uncertainty evaluation of different calibration protocols and ionization chambers for low-energy surface brachytherapy dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Candela-Juan, C., E-mail: ccanjuan@gmail.com [Radiation Oncology Department, La Fe University and Polytechnic Hospital, Valencia 46026 (Spain); Vijande, J. [Department of Atomic, Molecular, and Nuclear Physics, University of Valencia, Burjassot 46100, Spain and Instituto de Física Corpuscular (UV-CSIC), Paterna 46980 (Spain); García-Martínez, T. [Radiation Oncology Department, Hospital La Ribera, Alzira 46600 (Spain); Niatsetski, Y.; Nauta, G.; Schuurman, J. [Elekta Brachytherapy, Veenendaal 3905 TH (Netherlands); Ouhib, Z. [Radiation Oncology Department, Lynn Regional Cancer Center, Boca Raton Community Hospital, Boca Raton, Florida 33486 (United States); Ballester, F. [Department of Atomic, Molecular, and Nuclear Physics, University of Valencia, Burjassot 46100 (Spain); Perez-Calatayud, J. [Radiation Oncology Department, La Fe University and Polytechnic Hospital, Valencia 46026, Spain and Department of Radiotherapy, Clínica Benidorm, Benidorm 03501 (Spain)

    2015-08-15

    Purpose: A surface electronic brachytherapy (EBT) device is in fact an x-ray source collimated with specific applicators. Low-energy (<100 kVp) x-ray beam dosimetry faces several challenges that need to be addressed. A number of calibration protocols have been published for x-ray beam dosimetry. The media in which measurements are performed are the fundamental difference between them. The aim of this study was to evaluate the surface dose rate of a low-energy x-ray source with small field applicators using different calibration standards and different small-volume ionization chambers, comparing the values and uncertainties of each methodology. Methods: The surface dose rate of the EBT unit Esteya (Elekta Brachytherapy, The Netherlands), a 69.5 kVp x-ray source with applicators of 10, 15, 20, 25, and 30 mm diameter, was evaluated using the AAPM TG-61 (based on air kerma) and International Atomic Energy Agency (IAEA) TRS-398 (based on absorbed dose to water) dosimetry protocols for low-energy photon beams. A plane parallel T34013 ionization chamber (PTW Freiburg, Germany) calibrated in terms of both absorbed dose to water and air kerma was used to compare the two dosimetry protocols. Another PTW chamber of the same model was used to evaluate the reproducibility between these chambers. Measurements were also performed with two different Exradin A20 (Standard Imaging, Inc., Middleton, WI) chambers calibrated in terms of air kerma. Results: Differences between surface dose rates measured in air and in water using the T34013 chamber range from 1.6% to 3.3%. No field size dependence has been observed. Differences are below 3.7% when measurements with the A20 and the T34013 chambers calibrated in air are compared. Estimated uncertainty (with coverage factor k = 1) for the T34013 chamber calibrated in water is 2.2%–2.4%, whereas it increases to 2.5% and 2.7% for the A20 and T34013 chambers calibrated in air, respectively. The output factors, measured with the PTW chambers

  1. Reconstructive dosimetry of radiological accidents - a brazilian case study of industrial gammagraphy

    International Nuclear Information System (INIS)

    Silva, Francisco Cesar Augusto da; Hunt, John G.; Ramalho, Adriana; Pinto, Livia M.F. Amalfi

    2001-01-01

    In may 2000, an operator of industrial gammagraphy, during a work of maintenance of a cobalt source irradiator, suffered a radiological accident which caused serious consequences for its left hand. Specialists who work in the Group of Overexposure Analysis (GADE/IRD/CNEN), began the reconstructive dosimetry for estimate the radiation dose. The objective was to determine the real dose received by the operator and to make possible the medical evaluation and to prescribe the medical procedures for the involved victim's treatment. This work presents the reconstructive dosimetry done by theoretical, experimental and computation methods for determining the radiation doses of the operator. Related to the computation method a program was used for external dose calculation based on Monte Carlo's Method and a human body simulator composed by voxels. It is also showed values of the effective and equivalent doses that caused serious lesions in the operator's hand. (author)

  2. Evaluation of some water - equivalent plastics as phantom materials for electron dosimetry

    International Nuclear Information System (INIS)

    Mihailescu, D.; Borcia, C.

    2005-01-01

    In the International Code of Practice for Dosimetry TRS-398 published by the International Atomic Energy Agency (IAEA), water is recommended as the reference medium for the determination of absorbed dose for high-energy electron beams. Plastic phantoms may be used under certain circumstances (electron energy below 10 MeV, R 50 2 ) for electron beam dosimetry. In this case, a depth-scaling factor is required for the conversion of depth in solid phantoms to depth in water. A fluence-scaling factor is also necessary for converting ionization chamber readings in plastic phantom to readings in water. The aim of this paper is to calculate, using Monte Carlo simulations, the depth-scaling factors c pl and fluence-scaling factors h pl of some commercially available water substitute solid phantoms in order to evaluate their water equivalency. Two sets of calculations were performed: one for electron pencil beams and another for 10 x 10 cm 2 parallel beams, both of which are normally incident on water and solid phantoms. We used only mono-energetic beams of 6, 9, 12, 15, and 18 MeV. The results were compared with TRS-398 recommended values. In the case of pencil beams, we found that by applying the TRS-398 protocol, unacceptable uncertainties (up to 10%) were introduced in the dose distribution calculations. By contrast, TRS-398 can safely be used for 10 x 10 cm 2 beams (reference beams). In this case, uncertainties lower than 1% were obtained, what was in agreement with other published data. (authors)

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

    Science.gov (United States)

    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. TU-E-201-02: Eye Lens Dosimetry From CT Perfusion Studies

    International Nuclear Information System (INIS)

    Zhang, D.

    2015-01-01

    Madan M. Rehani, Massachusetts General Hospital and Harvard Medical School, Boston Methods for Eye Lens Dosimetry and Studies On Lens Opacities with Interventionalists Radiation induced cataract is a major threat among staff working in interventional suites. Nearly 16 million interventional procedures are performed annually in USA. Recent studies by the principal investigator’s group, primarily among interventional cardiologists, on behalf of the International Atomic Energy Agency, show posterior subcapsular (PSC) changes in the eye lens in 38–53% of main operators and 21–45% of support staff. These changes have potential to lead to cataract in future years, as per information from A-Bomb survivors. The International Commission on Radiological Protection has reduced dose limit for staff by a factor of 7.5 (from 150 mSv/y to 20 mSv/y). With increasing emphasis on radiation induced cataracts and reduction in threshold dose for eye lens, there is a need to implement strategies for estimating eye lens dose. Unfortunately eye lens dosimetry is at infancy when it comes to routine application. Various approaches are being tried namely direct measurement using active or passive dosimeters kept close to eyes, retrospective estimations and lastly correlating patient dose in interventional procedures with staff eye dose. The talk will review all approaches available and ongoing active research in this area, as well as data from surveys done in Europe on status of eye dose monitoring in interventional radiology and nuclear medicine. The talk will provide update on how good is Hp(10) against Hp(3), estimations from CTDI values, Monte Carlo based simulations and current status of eye lens dosimetry in USA and Europe. The cataract risk among patients is in CT examinations of the head. Since radiation induced cataract predominantly occurs in posterior sub-capsular (PSC) region and is thus distinguishable from age or drug related cataracts and is also preventable, actions on

  5. TU-E-201-02: Eye Lens Dosimetry From CT Perfusion Studies

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, D. [Toshiba America Medical Systems (United States)

    2015-06-15

    Madan M. Rehani, Massachusetts General Hospital and Harvard Medical School, Boston Methods for Eye Lens Dosimetry and Studies On Lens Opacities with Interventionalists Radiation induced cataract is a major threat among staff working in interventional suites. Nearly 16 million interventional procedures are performed annually in USA. Recent studies by the principal investigator’s group, primarily among interventional cardiologists, on behalf of the International Atomic Energy Agency, show posterior subcapsular (PSC) changes in the eye lens in 38–53% of main operators and 21–45% of support staff. These changes have potential to lead to cataract in future years, as per information from A-Bomb survivors. The International Commission on Radiological Protection has reduced dose limit for staff by a factor of 7.5 (from 150 mSv/y to 20 mSv/y). With increasing emphasis on radiation induced cataracts and reduction in threshold dose for eye lens, there is a need to implement strategies for estimating eye lens dose. Unfortunately eye lens dosimetry is at infancy when it comes to routine application. Various approaches are being tried namely direct measurement using active or passive dosimeters kept close to eyes, retrospective estimations and lastly correlating patient dose in interventional procedures with staff eye dose. The talk will review all approaches available and ongoing active research in this area, as well as data from surveys done in Europe on status of eye dose monitoring in interventional radiology and nuclear medicine. The talk will provide update on how good is Hp(10) against Hp(3), estimations from CTDI values, Monte Carlo based simulations and current status of eye lens dosimetry in USA and Europe. The cataract risk among patients is in CT examinations of the head. Since radiation induced cataract predominantly occurs in posterior sub-capsular (PSC) region and is thus distinguishable from age or drug related cataracts and is also preventable, actions on

  6. Radiation dosimetry

    CERN Document Server

    Hine, Gerald J; Hine, Gerald J

    1956-01-01

    Radiation Dosimetry focuses on the advancements, processes, technologies, techniques, and principles involved in radiation dosimetry, including counters and calibration and standardization techniques. The selection first offers information on radiation units and the theory of ionization dosimetry and interaction of radiation with matter. Topics include quantities derivable from roentgens, determination of dose in roentgens, ionization dosimetry of high-energy photons and corpuscular radiations, and heavy charged particles. The text then examines the biological and medical effects of radiation,

  7. Film dosimetry using a smart device camera: a feasibility study for point dose measurements

    Science.gov (United States)

    Aland, Trent; Jhala, Ekta; Kairn, Tanya; Trapp, Jamie

    2017-10-01

    In this work, a methodology for using a smartphone camera, in conjunction with a light-tight box operating in reflective transmission mode, is investigated as a proof of concept for use as a film dosimetry system. An imaging system was designed to allow the camera of a smartphone to be used as a pseudo densitometer. Ten pieces of Gafchromic EBT3 film were irradiated to doses up to 16.89 Gy and used to evaluate the effects of reproducibility and orientation, as well as the ability to create an accurate dose response curve for the smartphone based dosimetry system, using all three colour channels. Results were compared to a flatbed scanner system. Overall uncertainty was found to be best for the red channel with an uncertainty of 2.4% identified for film irradiated to 2.5 Gy and digitised using the smartphone system. This proof of concept exercise showed that although uncertainties still exceed a flatbed scanner system, the smartphone system may be useful for providing point dose measurements in situations where conventional flatbed scanners (or other dosimetry systems) are unavailable or unaffordable.

  8. Dosimetry techniques applied to thermoluminescent age estimation

    International Nuclear Information System (INIS)

    Erramli, H.

    1986-12-01

    The reliability and the ease of the field application of the measuring techniques of natural radioactivity dosimetry are studied. The natural radioactivity in minerals in composed of the internal dose deposited by alpha and beta radiations issued from the sample itself and the external dose deposited by gamma and cosmic radiations issued from the surroundings of the sample. Two technics for external dosimetry are examined in details. TL Dosimetry and field gamma dosimetry. Calibration and experimental conditions are presented. A new integrated dosimetric method for internal and external dose measure is proposed: the TL dosimeter is placed in the soil in exactly the same conditions as the sample ones, during a time long enough for the total dose evaluation [fr

  9. Three-dimensional dosimetry in brachytherapy: A MAGAT study

    International Nuclear Information System (INIS)

    Lin, M.-H.; Huang, T.-C.; Kao, M.-J.; Wu, Jay; Chen, C.-L.; Wu, T.-H.

    2009-01-01

    This study is to evaluate the influence of using different matrix size of smoothing filter for image post-processing and various slice thickness during MR imaging on dose estimation in Ir-192 HDR brachytherapy via normoxic polymer gel dosimeter. Our results show its sensitive nature in gel dosimeter while changing these parameters, among which the combination of 2 mm slice thickness of MR images and [5x5] smoothing filter are considered the optimal parameters to provide accurate dose estimations and isodose curves.

  10. Direct comparison of radiation dosimetry of six PET tracers using human whole-body imaging and murine biodistribution studies

    International Nuclear Information System (INIS)

    Sakata, Muneyuki; Oda, Keiichi; Toyohara, Jun; Ishii, Kenji; Nariai, Tadashi; Ishiwata, Kiichi

    2013-01-01

    We investigated the whole-body biodistributions and radiation dosimetry of five 11 C-labeled and one 18 F-labeled radiotracers in human subjects, and compared the results to those obtained from murine biodistribution studies. The radiotracers investigated were 11 C-SA4503, 11 C-MPDX, 11 C-TMSX, 11 C-CHIBA-1001, 11 C-4DST, and 18 F-FBPA. Dynamic whole-body positron emission tomography (PET) was performed in three human subjects after a single bolus injection of each radiotracer. Emission scans were collected in two-dimensional mode in five bed positions. Regions of interest were placed over organs identified in reconstructed PET images. The OLINDA program was used to estimate radiation doses from the number of disintegrations of these source organs. These results were compared with the predicted human radiation doses on the basis of biodistribution data obtained from mice by dissection. The ratios of estimated effective doses from the human-derived data to those from the mouse-derived data ranged from 0.86 to 1.88. The critical organs that received the highest absorbed doses in the human- and mouse-derived studies differed for two of the six radiotracers. The differences between the human- and mouse-derived dosimetry involved not only the species differences, including faster systemic circulation of mice and differences in the metabolism, but also measurement methodologies. Although the mouse-derived effective doses were roughly comparable to the human-derived doses in most cases, considerable differences were found for critical organ dose estimates and pharmacokinetics in certain cases. Whole-body imaging for investigation of radiation dosimetry is desirable for the initial clinical evaluation of new PET probes prior to their application in subsequent clinical investigations. (author)

  11. Study of the replacement correction factors for ionization chamber dosimetry by Monte Carlo simulations

    Science.gov (United States)

    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

  12. Dosimetry Service

    CERN Multimedia

    2006-01-01

    Cern Staff and Users can now consult their dose records for an individual or an organizational unit with HRT. Please see more information on our web page: http://cern.ch/rp-dosimetry Dosimetry Service is open every morning from 8.30 - 12.00. Closed in the afternoons. We would like to remind you that dosimeters cannot be sent to customers by internal mail. Short-term dosimeters (VCT's) must always be returned to the Service after the use and must not be left on the racks in the experimental areas or in the secretariats. Dosimetry Service Tel. 7 2155 Dosimetry.service@cern.ch http://cern.ch/rp-dosimetry

  13. Dosimetry on the radiological risks prevention in radiotherapy

    International Nuclear Information System (INIS)

    Fornet R, O. M.; Perez G, F.

    2014-08-01

    Dosimetry in its various forms plays a determining role on the radiological risks prevention in radiotherapy. To prove this in this paper is shown an analysis based on the risk matrix method, how the dosimetry can influence in each stages of a radiotherapy service; installation and acceptance, operation, maintenance and calibration. For each one of these stages the role that can play is analyzed as either the initiating event of a radiological accident or limiting barrier of these events of the dosimetric processes used for the individual dosimetry, the area monitoring, fixed or portable, for radiation beam dosimetry and of the patients for a radiotherapy service with cobalt-therapy equipment. The result of the study shows that the application of a prospective approach in the role evaluation of dosimetry in the prevention and mitigation of the consequences of a radiological accident in radiotherapy is crucial and should be subject to permanent evaluation at each development stage of these services. (author)

  14. Radiation dosimetry in nuclear medicine

    International Nuclear Information System (INIS)

    Stabin, M.G.; Tagesson, M.; Ljungberg, M.; Strand, S.E.; Thomas, S.R.

    1999-01-01

    Radionuclides are used in nuclear medicine in a variety of diagnostic and therapeutic procedures. A knowledge of the radiation dose received by different organs in the body is essential to an evaluation of the risks and benefits of any procedure. In this paper, current methods for internal dosimetry are reviewed, as they are applied in nuclear medicine. Particularly, the Medical Internal Radiation Dose (MIRD) system for dosimetry is explained, and many of its published resources discussed. Available models representing individuals of different age and gender, including those representing the pregnant woman are described; current trends in establishing models for individual patients are also evaluated. The proper design of kinetic studies for establishing radiation doses for radiopharmaceuticals is discussed. An overview of how to use information obtained in a dosimetry study, including that of the effective dose equivalent (ICRP 30) and effective dose (ICRP 60), is given. Current trends and issues in internal dosimetry, including the calculation of patient-specific doses and in the use of small scale and microdosimetry techniques, are also reviewed

  15. Study of Optically Stimulated Luminescence of LiF:Mg,Ti for beta and gamma dosimetry

    International Nuclear Information System (INIS)

    Matsushima, Luciana C.; Veneziani, Glauco R.; Campos, Letícia L.

    2013-01-01

    Modern advances in radiation medicine – radiodiagnosis, radiotherapy and interventional radiography – each present dosimetry challenges for the medical physicist that did not exist previously. In all of these areas a constant balance has to be made between the treatment necessary to destroy the tumor and the unnecessary exposure of healthy tissue. Innovative applications of OSL dosimetry are now appearing in each of these areas to help the medical physicist and oncologist design the most effective, and least deleterious, treatment for their patients. High sensitivity, precise delivery of light, fast readout times, simpler readers and easier automation are the main advantages of OSL in comparison with TLD. This work aimed to study the application of OSL technique using lithium fluoride dosimeters doped with magnesium and titanium (LiF:Mg,Ti) for application in beta and gamma dosimetry. -- Highlights: •Study of Optically Stimulated Luminescence of LiF:Mg,Ti and microLiF:Mg,Ti. •OSL response of TLD-100 dosimeters to beta and gamma radiation. •Analysis of repeatability and lowest levels of detection of detectors LiF:Mg,Ti

  16. How can bio dosimetry measurements be used to improve radiation epidemiologic studies?

    International Nuclear Information System (INIS)

    Simon, Steven L.; Bouville, Andre; Kleinerman, Ruth

    2008-01-01

    Full text: Bio dosimetry measurements can be used potentially to improve radiation epidemiologic studies by providing a means to corroborate analytical or model-based dose estimates, to assess bias in models and their dose estimates, and reduce uncertainty in individual or group-average doses. Radiation epidemiologic studies typically rely on accurate estimation of doses to the whole body or to specific organs for numerous individuals in order to derive reliable estimates of risk of cancer or other medical conditions. However, dose estimates whether based on analytical dose reconstruction (i.e., models) or personnel monitoring measurements, e.g., film-badges, are associated with considerable and varying degrees of uncertainty. Uncertainty is a product of many factors; persons were exposed many years or decades earlier and usually only inadequate data or measurements are available. While bio dosimetry has begun to play a more significant role in long-term health risk studies, its use is still limited in that context, primarily due sometimes to inadequate limits of detection, inter-individual variability of the signal measured, and high per-sample cost. Presently, the most suitable bio dosimetry methods for epidemiologic studies are chromosome aberration frequencies from fluorescence in situ hybridization (FISH) of peripheral blood lymphocytes and electron paramagnetic resonance (EPR) measurements made on tooth enamel, with detection limits of approximately 0.3 to 0.5 Gy, and as low as 0.03 Gy for FISH and EPR, respectively. Presently, both methods are invasive and require obtaining either blood or teeth. Though both FISH and EPR have been used in a variety of large long-term health risk studies including those of a-bomb survivors and various occupational and environmental exposures, only recently has considerable thought been given to how these data can be used in epidemiologic studies in any but rudimentary ways. Key issues to consider are the representativeness of

  17. Establishment of a dosimetry method for the exposure evaluation to the ultraviolet radiation

    International Nuclear Information System (INIS)

    Gronchi, Claudia Carla

    2009-01-01

    A dosimetric method for the exposure evaluation to ultraviolet radiation was established with Al 2 O 3 :C InLight detectors and an OSL microStar reader and software, of Landauer, associated to the techniques of Optically Stimulated Luminescence (OSL) and Photo transferred Optically Stimulated Luminescence (PTOSL). The main phases of this work were: characterization of the Al 2 O 3 :C InLight detectors, without pre-conditioning, exposed to ultraviolet radiation (RUV) of solar and artificial sources, using the OSL technique; characterization of the Al 2 O 3 :C InLight detectors, pre-conditioned, exposed to RUV solar and artificial sources, using the PTOSL technique; practical applications of the Al 2 O 3 :C InLight detectors to the solar and artificial RUV, originating from TIG (Tungsten Inert Gas) and electric welding. The Al 2 O 3 :C InLight detectors presented satisfactory OSL and PTOSL responses in relation to the parameters: wavelength, UV illumination time, irradiance, radiance exposure and angular dependence to the RUV. Those detectors presented maximum OSL and PTOSL stimulation for the wavelength of 330 nm, showing that they are may be useful for UVA radiation detection and dosimetry. (author)

  18. In vivo dose evaluation during gynaecological radiotherapy using L-alanine/ESR dosimetry

    International Nuclear Information System (INIS)

    Burg Rech, Amanda; Baffa, Oswaldo; Barbi, Gustavo Lazzaro; Almeida Ventura, Luiz Henrique; Silva Guimaraes, Flavio; Oliveira, Harley Francisco

    2014-01-01

    The dose delivered by in vivo 3-D external beam radiation therapy (EBRT) was verified with L-alanine/electron spin resonance (ESR) dosimetry for patients diagnosed with gynaecological cancer. Measurements were performed with an X-band ESR spectrometer. Dosemeters were positioned inside the vaginal cavity with the assistance of an apparatus specially designed for this study. Previous phantom studies were performed using the same conditions as in the in vivo treatment. Four patients participated in this study during 20-irradiation sessions, giving 220 dosemeters to be analysed. The doses were determined with the treatment planning system, providing dose confirmation. The phantom study resulted in a deviation between -2.5 and 2.1 %, and for the in vivo study a deviation between -9.2 and 14.2 % was observed. In all cases, the use of alanine with ESR was effective for dose assessment, yielding results consistent with the values set forth in the International Commission on Radiation Units and Measurements (ICRU) reports. (authors)

  19. Whole-body radiation dosimetry of 2-[18F]Fluoro-A-85380 in human PET imaging studies

    International Nuclear Information System (INIS)

    Obrzut, Sebastian L.; Koren, Andrei O.; Mandelkern, Mark A.; Brody, Arthur L.; Hoh, Carl K.; London, Edythe D.

    2005-01-01

    2-[ 18 F]Fluoro-A-85380 (2-[ 18 F]fluoro-3-(2(S)-azetidinylmethoxy)pyridine, 2-[ 18 F]FA) is a recently developed PET radioligand for noninvasive imaging of nicotinic acetylcholine receptors. Previous radiation absorbed dose estimates for 2-[ 18 F]FA were limited to evaluation of activity in only several critical organs. Here, we performed 2-[ 18 F]FA radiation dosimetry studies on two healthy human volunteers to obtain data for all important body organs. Intravenous injection of 2.9 MBq/kg of 2-[ 18 F]FA was followed by dynamic PET imaging. Regions of interest were placed over images of each organ to generate time-activity curves, from which we computed residence times. Radiation absorbed doses were calculated from the residence times using the MIRDOSE 3.0 program (version 3.0, ORISE, Oak Ridge, TN). The urinary bladder wall receives the highest radiation absorbed dose (0.153 mGy/MBq, 0.566 rad/mCi, for a 2.4-h voiding interval), followed by the liver (0.0496 mGy/MBq, 0.184 rad/mCi) and the kidneys (0.0470 mGy/MBq, 0.174 rad/mCi). The mean effective dose equivalent is estimated to be 0.0278 mSv/MBq (0.103 rem/mCi), indicating that radiation dosimetry associated with 2-[ 18 F]FA is within acceptable limits

  20. Worldwide bioassay data resources for plutonium/americium internal dosimetry studies

    International Nuclear Information System (INIS)

    Miller, G.; Bertelli, L.; Little, T.; Guilmette, R.; Riddell, T.; Filipy, R.

    2005-01-01

    Full text: Biokinetic models are the scientific underpinning of internal dosimetry. These models describe how materials of interest taken into the body by various routes (for example inhalation) are transported through the body, allowing the modelling of bioassay measurements and the estimation of radiation dose. The International Commission on Radiation Protection (ICRP) publishes biokinetic models for use in internal dosimetry. These models represent the consensus judgement of a committee of experts, based on human and animal data. Nonetheless, it is important to validate biokinetic models using directly applicable data, in a scientifically transparent manner, especially for internal dosimetry research purposes (as opposed to radiation protection), as in epidemiology studies. Two major goals would be to determine individual variations of model parameters for the purpose of assessing this source of uncertainty in internal dose calculations, and to determine values of workplace specific parameters (such as particle solubility in lung fluids) for different representative workplaces. Furthermore, data on the observed frequency of intakes under various conditions can be used in the interpretation of bioassay data. All of the above may be couched in the terminology of Bayesian statistical analysis and amount to the determination of the Bayesian prior probability distributions needed in a Bayesian interpretation of bioassay data. The authors have direct knowledge of several significant databases of plutonium/americium bioassay data (including autopsy data). The purpose of this paper is to acquaint the worldwide community with these resources and to invite others who may know of other such databases to participate with us in a publication that would document the content, form, and the procedures for seeking access to these databases. These databases represent a tremendous scientific resource in this field. Examples of databases known to the authors include: the

  1. Voice Use Among Music Theory Teachers: A Voice Dosimetry and Self-Assessment Study.

    Science.gov (United States)

    Schiller, Isabel S; Morsomme, Dominique; Remacle, Angélique

    2017-07-25

    This study aimed (1) to investigate music theory teachers' professional and extra-professional vocal loading and background noise exposure, (2) to determine the correlation between vocal loading and background noise, and (3) to determine the correlation between vocal loading and self-evaluation data. Using voice dosimetry, 13 music theory teachers were monitored for one workweek. The parameters analyzed were voice sound pressure level (SPL), fundamental frequency (F0), phonation time, vocal loading index (VLI), and noise SPL. Spearman correlation was used to correlate vocal loading parameters (voice SPL, F0, and phonation time) and noise SPL. Each day, the subjects self-assessed their voice using visual analog scales. VLI and self-evaluation data were correlated using Spearman correlation. Vocal loading parameters and noise SPL were significantly higher in the professional than in the extra-professional environment. Voice SPL, phonation time, and female subjects' F0 correlated positively with noise SPL. VLI correlated with self-assessed voice quality, vocal fatigue, and amount of singing and speaking voice produced. Teaching music theory is a profession with high vocal demands. More background noise is associated with increased vocal loading and may indirectly increase the risk for voice disorders. Correlations between VLI and self-assessments suggest that these teachers are well aware of their vocal demands and feel their effect on voice quality and vocal fatigue. Visual analog scales seem to represent a useful tool for subjective vocal loading assessment and associated symptoms in these professional voice users. Copyright © 2017 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

  2. Evaluation of [18F]Mefway biodistribution and dosimetry based on whole-body PET imaging of mice.

    Science.gov (United States)

    Constantinescu, Cristian C; Sevrioukov, Evgueni; Garcia, Adriana; Pan, Min-Liang; Mukherjee, Jogeshwar

    2013-04-01

    [(18)F]Mefway is a novel radiotracer specific to the serotonin 5-HT1A receptor class. In preparation for using this tracer in humans, we have performed whole-body PET studies in mice to evaluate the biodistribution and dosimetry of [(18)F]Mefway. Six mice (three females and three males) received IV injections of [(18)F]Mefway and were scanned for 2 h in an Inveon-dedicated PET scanner. Each animal also received a high-resolution CT scan using an Inveon CT. The CT images were used to draw volume of interest on the following organs: the brain, large intestine, stomach, heart, kidneys, liver, lungs, pancreas, bone, spleen, testes, thymus, gallbladder, uterus, and urinary bladder. All organ time-activity curves without decay correction were normalized to the injected activity. The area under the normalized curves was then used to compute the residence times in each organ. Data were analyzed using PMOD and Matlab software. The absorbed doses in mouse organs were computed using the RAdiation Dose Assessment Resource animal models for dose assessment. The residence times in mouse organs were converted to human values using scale factors based on differences between organ and body weights. OLINDA/EXM 1.1 software was used to compute the absorbed human doses in multiple organs for both female and male phantoms. The highest mouse residence times were found in the liver, urinary bladder, and kidneys. The largest doses in mice were found in the urinary bladder (critical organ), kidney, and liver for both females and males, indicating primary elimination via urinary system. The projected human effective doses were 1.21E - 02 mSv/MBq for the adult female model and 1.13E - 02 mSv/MBq for the adult male model. The estimated human biodistribution of [(18)F]Mefway was similar to that of [(11)C]WAY 100,635, a 5-HT1A tracer for which dosimetry has been evaluated in humans. The elimination of radiotracer was primarily via the kidney and urinary bladder with the urinary

  3. Standardization of the Fricke gel dosimetry method and tridimensional dose evaluation using the magnetic resonance imaging technique

    International Nuclear Information System (INIS)

    Cavinato, Christianne Cobello

    2009-01-01

    This study standardized the method for obtaining the Fricke gel solution developed at IPEN. The results for different gel qualities used in the preparation of solutions and the influence of the gelatin concentration in the response of dosimetric solutions were compared. Type tests such as: dose response dependence, minimum and maximum detection limits, response reproducibility, among others, were carried out using different radiation types and the Optical Absorption (OA) spectrophotometry and Magnetic Resonance (MR) techniques. The useful dose ranges for Co 60 gamma radiation and 6 MeV photons are 0,4 to 30,0 Gy and 0,5 to 100,0 Gy , using OA and MR techniques, respectively. A study of ferric ions diffusion in solution was performed to determine the optimum time interval between irradiation and samples evaluation; until 2,5 hours after irradiation to obtain sharp MR images. A spherical simulator consisting of Fricke gel solution prepared with 5% by weight 270 Bloom gelatine (national quality) was developed to be used to three-dimensional dose assessment using the Magnetic Resonance Imaging (MRI) technique. The Fricke gel solution prepared with 270 Bloom gelatine, that, in addition to low cost, can be easily acquired on the national market, presents satisfactory results on the ease of handling, sensitivity, response reproducibility and consistency. The results confirm their applicability in the three-dimensional dosimetry using MRI technique. (author)

  4. Management of individual and collective dosimetry at Fessenheim nuclear plant. Evaluation after refueling shutdown

    International Nuclear Information System (INIS)

    Lamarre, D.; Waller, A.

    1980-01-01

    The principle of dosimetry management chosen by Fessenheim nuclear power station was originally consisted of two phases: - an automatic acquisition of individual doses realized by stylodosimeter readers; - a deferred data processing by computer. The whole system has not been used during the shutdown for the first refuelling of unit number one in view of encountered difficulties with perfecting of automatic readers prototype, this last phase has been replaced by a manual acquisition of doses. The dosimetry data processing has two main objects: - supervision of individual dosimetry for people who work in the nuclear power station; - knowledge of doses assigned for each working and equipment. Moreover, a first dosimetric result of the shutdown for refuelling of unit number one, enables to notice the workings which doses are the most important and written in percentage of total doses: regulatory controls: about 19%; - steam generators working: 16%; - working decontamination and making health physics screen (lock chamber) 10% [fr

  5. A contribution to the study of the biological dosimetry in clinical radiopathology

    International Nuclear Information System (INIS)

    Eston, T.E. de.

    1983-01-01

    The effects of total body irradiation with different radiation doses from a 4MeV linear accelerator on organs and tissues of adult male rabbits were studied. Doses of 0.50, 2.00, 6.00 and 8.00 Gy were applied. Different organic parameters were evaluated before and after various periods of the post-irradiation time. Mortality did not occured for 0.50 or 2.00 Gy, but morbility was greater in comparison with the control; sexual potency was maintained. 'Impotentia colundi' occured with 6 Gy. A small loss of weight occured with 2.00 Gy and a higher loss for 6.00 Gy, with later recovery. Blood parameters varied even for lowest dose. Alterations were evident in the bone marrow activity for 2.00 and 6.00 Gy. Spermatides, spermatocytes and mature spermatozoids were affect even by low doses, the laters loosing motility. Significant difference was observed in the relation DNA/RNA for irradiated-and control animals. The results showed that T3 asssay could serve as 'biological indicator' of irradiation in a period of at least 7 hours and for doses of 4Gy or more. Using the kinetic method, an increase of glutamic oxalacetic transaminase (GOT) seric levels was observed for 6.00 Gy after 7 hours and a decrease for the glutamic pyruvic transaminase (GPT). Fasting glycemy and catecolamines urinary extraction were not statiscally significants. The study of chromosomal aberrations that occur in lymphocytes after 'in vitro' irradiation showed that this is at the present moment the most efficient method for biological dosimetry. (M.A.) [pt

  6. Evaluation of different polymers for fast neutron personnel dosimetry using electrochemical etching

    International Nuclear Information System (INIS)

    Gammage, R.B.; Cotter, S.J.

    1977-01-01

    There is considerable optimism for the enhancement by electrochemical etching of fast neutron-induced recoil tracks in polycarbonate for the purpose of personnel dosimetry. The threshold energy, however, is rather high. A desirable improvement would be to lower this energy below 1 MeV. With this objective in mind, we have commenced an investigation of cellulose acetate, triacetate, and acetobutyrate in addition to polycarbonate. These cellulose derivatives are chemically more reactive and physically weaker than polycarbonate. It might, therefore, be possible to initiate the electrochemical amplification at the sites of shorter recoil atom damage tracks than is possible with polycarbonate. Some characteristics important for electrochemically etching in aqueous electrolytes are listed. Chemical etching is combined with treeing, an electrical breakdown process that starts when the dielectric strength is exceeded. These mechanical and electrical properties pertain to the dry plastics. The absorption of water molecules and electrolyte ions will cause these values to be reduced. Results and conclusions of the study are presented

  7. Evaluation of a patient-specific Monte Carlo software for CT dosimetry

    International Nuclear Information System (INIS)

    Myronakis, M.; Perisinakis, K.; Tzedakis, A.; Gourtsoyianni, S.; Damilakis, J.

    2009-01-01

    The aim was to validate the ImpactMC computed tomography (CT) dosimetry software that allows patient-specific dose determination. Measured values of head- and body-weighted CT dose index (CTDIw) were compared with corresponding values derived using ImpactMC software. A physical anthropomorphic phantom simulating the average adult was employed to study the effect of exposure parameters used to produce the input image set on a normalised dose output and the relationship between exposure parameters selected for simulation on the dose output. The difference between CTDIw values obtained through measurements and simulations were found to be up to 12.8 and 18.3% for head and body phantoms, respectively. Exposure parameters of the image set used as input were found to have a minor impact on the normalised dose output. Simulations confirmed the expected linear relationship between dose and tube load and the power law relationship between dose and tube potential. Results demonstrate that ImpactMC may be capable of providing reliable CT dose estimates. (authors)

  8. Evaluation of an ionization chamber response at small distances during dosimetry of gamma radiation beams

    Energy Technology Data Exchange (ETDEWEB)

    Afonso, Luciana C.; Potiens, Maria da Penha A.; Caldas, Linda V.E. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)]. E-mail: lafonso@ipen.br; mppalbu@ipen.br; lcaldas@ipen.br

    2007-07-01

    The beam dosimetry measurements of a gamma irradiator, utilized for calibration of mainly portable radiation monitors, at the Calibration Laboratory of IPEN, have been taken between the source-instrument distance of 1 m and 4 m. Due to the source decay and instruments with higher dose rate ranges, calibrations at distances smaller than 1 m are necessary. For this purpose, a 30 cm{sup 3} ionization chamber calibrated against a secondary standard system was utilized. The use of this chamber is appropriate, because it can be totally irradiated. The behavior of this ionization chamber was studied in terms of: repeatability, stability and current leakage, using a {sup 90}Sr+{sup 90}Y source. The repeatability test presented uncertainties lower than {+-}0.5%. Analyzing the stability results, the variation did not exceed {+-}1.0%. The current leakage did not exceed 0.5% of the reference value. The measurements at the irradiator beams were taken at smaller distances than 1 m (in steps of 10 cm). The distance square inverse law was verified for both {sup 137}Cs and {sup 60}Co sources; the variations did not exceed {+-}5%, according to the ISO 4037-1 standard. (author)

  9. Evaluation of the Gafchromic{sup Registered-Sign} EBT2 film for the dosimetry of radiosurgical beams

    Energy Technology Data Exchange (ETDEWEB)

    Larraga-Gutierrez, Jose M. [Laboratorio de Fisica Medica, Instituto Nacional de Neurologia y Neurocirugia, Insurgentes Sur 3877, Mexico D.F. 14269 (Mexico) and Unidad de Radioneurocirugia, Instituto Nacional de Neurologia y Neurocirugia, Insurgentes Sur 3877, C.P. 14269, Mexico D.F. 14269 (Mexico); Garcia-Hernandez, Diana [Laboratorio de Fisica Medica, Instituto Nacional de Neurologia y Neurocirugia, Insurgentes Sur 3877, Mexico D.F. 14269 (Mexico); Garcia-Garduno, Olivia A. [Laboratorio de Fisica Medica, Instituto Nacional de Neurologia y Neurocirugia, Insurgentes Sur 3877, Mexico D.F. 14269 (Mexico) and Centro de Investigacion en Ciencia Aplicada y Tecnologia Avanzada, Unidad Legaria, Instituto Politecnico Nacional, Legaria 694, Mexico D.F. 11500 (Mexico); Galvan de la Cruz, Olga O. [Unidad de Radioneurocirugia, Instituto Nacional de Neurologia y Neurocirugia, Insurgentes Sur 3877, Mexico D.F. 14269 (Mexico); Ballesteros-Zebadua, Paola [Laboratorio de Fisica Medica, Instituto Nacional de Neurologia y Neurocirugia, Insurgentes Sur 3877, Mexico D.F. 14269 (Mexico) and Unidad de Radioneurocirugia, Instituto Nacional de Neurologia y Neurocirugia, Insurgentes Sur 3877, Mexico D.F. 14269 (Mexico); Esparza-Moreno, Karina P. [Facultad de Medicina, Universidad Autonoma del Estado de Mexico, Paseo Tollocan, Toluca, Estado De Mexico 50180 (Mexico)

    2012-10-15

    Purpose: Radiosurgery uses small fields and high-radiation doses to treat intra- and extracranial lesions in a single session. The lack of a lateral electronic equilibrium and the presence of high-dose gradients in these fields are challenges for adequate measurements. The availability of radiation detectors with the high spatial resolution required is restricted to only a few. Stereotactic diodes and EBT radiochromic films have been demonstrated to be good detectors for small-beam dosimetry. Because the stereotactic diode is the standard measurement for the dosimetry of radiosurgical beams, the goal of this work was to perform measurements with the radiochromic film Gafchromic{sup Registered-Sign} EBT2 and compare its results with a stereotactic diode. Methods: Total scatter factors, tissue maximum, and off-axis ratios from a 6 MV small photon beams were measured using EBT2 radiochromic film in a water phantom. The film-measured data were evaluated by comparing it with the data measured with a stereotactic field diode (IBA-Dosimetry). Results: The film and diode measurements had excellent agreement. The differences between the detectors were less than or equal to 2.0% for the tissue maximum and the off-axis ratios. However, for the total scatter factors, there were significant differences, up to 4.9% (relative to the reference field), for field sizes less than 1.0 cm. Conclusions: This work found that the Gafchromic{sup Registered-Sign} EBT2 film is adequate for small photon beam measurements, particularly for tissue maximum and off-axis ratios. However, careful attention must be taken when measuring output factors of small beams below 1.0 cm due to the film's energy dependence. The measurement differences may be attributable to the film's active layer composition because EBT2 incorporates higher Z elements (i.e., bromide and potassium), hence revealing a potential energy dependence for the dosimetry of small photon beams.

  10. Comparison of parameters affecting GNP-loaded choroidal melanoma dosimetry; Monte Carlo study

    Science.gov (United States)

    Sharabiani, Marjan; Asadi, Somayeh; Barghi, Amir Rahnamai; Vaezzadeh, Mehdi

    2018-04-01

    The current study reports the results of tumor dosimetry in the presence of gold nanoparticles (GNPs) with different sizes and concentrations. Due to limited number of works carried out on the brachytherapy of choroidal melanoma in combination with GNPs, this study was performed to determine the optimum size and concentration for GNPs which contributes the highest dose deposition in tumor region, using two phantom test cases namely water phantom and a full Monte Carlo model of human eye. Both water and human eye phantoms were simulated with MCNP5 code. Tumor dosimetry was performed for a typical point photon source with an energy of 0.38 MeV as a high energy source and 103Pd brachytherapy source with an average energy of 0.021 MeV as a low energy source in water phantom and eye phantom respectively. Such a dosimetry was done for different sizes and concentrations of GNPs. For all of the diameters, increase in concentration of GNPs resulted in an increase in dose deposited in the region of interest. In a certain concentration, GNPs with larger diameters contributed more dose to the tumor region, which was more pronounced using eye phantom. 100 nm was reported as the optimum size in order to achieve the highest energy deposition within the target. This work investigated the optimum parameters affecting macroscopic dose enhancement in GNP-aided brachytherapy of choroidal melanoma. The current work also had implications on using low energy photon sources in the presence of GNPs to acquire the highest dose enhancement. This study is conducted through four different sizes and concentrations of GNPs. Considering the sensitivity of human eye tissue, in order to report the precise optimum parameters affecting radiosensitivity, a comprehensive study on a wide range of sizes and concentrations are required.

  11. Evaluation of entrance surface-skin doses in animals submitted on exams of abdomen in veterinary radiology using Tl dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Veneziani, G. R.; Matsushima, L. C.; Campos, L. L. [Instituto de Pesquisas Energeticas e Nucleares, Gerencia de Metrologia das Radiacoes / CNEN, Av. Lineu Prestes 2242, Cidade Universitaria, 05508-000 Sao Paulo (Brazil); Filho, A. M., E-mail: venezianigr@gmail.com [Centro Universitario de Rio Petro - UNIRP, Rodovia Br 153 (Transbrasiliana), Km. 69 Sao Jose do Rio Preto, Sao Paulo (Brazil)

    2014-08-15

    The radiation protection has recently gained considerable attention in human medicine. In veterinary medicine has been some advances in radiodiagnostic and therapy for domestic animal like dogs and cats. It is notable the increase of the costs with domestic animals that are considered, by many people in the whole world, like members of family. However, an important parameter that must be taken into account is the increasing use of computed tomography and other equipment s that uses ionizing radiation, which may lead to comparatively high exposure of critical organs. The radiation dose is determined by the balance between therapeutic benefit and possible damage to surrounding normal tissues. This study aimed the evaluation of entrance surface-skin doses in dogs submitted to radiodiagnostic procedures of abdomen using the technique of thermoluminescent dosimetry (TLD). The radiation doses were measured using thermoluminescent dosimeters of LiF:Mg,Ti (TLD 100) and a dog phantom made with a plastic container, proportional to the dog size, fulfilled with water. (Author)

  12. Evaluation of entrance surface-skin doses in animals submitted on exams of abdomen in veterinary radiology using Tl dosimetry

    International Nuclear Information System (INIS)

    Veneziani, G. R.; Matsushima, L. C.; Campos, L. L.; Filho, A. M.

    2014-08-01

    The radiation protection has recently gained considerable attention in human medicine. In veterinary medicine has been some advances in radiodiagnostic and therapy for domestic animal like dogs and cats. It is notable the increase of the costs with domestic animals that are considered, by many people in the whole world, like members of family. However, an important parameter that must be taken into account is the increasing use of computed tomography and other equipment s that uses ionizing radiation, which may lead to comparatively high exposure of critical organs. The radiation dose is determined by the balance between therapeutic benefit and possible damage to surrounding normal tissues. This study aimed the evaluation of entrance surface-skin doses in dogs submitted to radiodiagnostic procedures of abdomen using the technique of thermoluminescent dosimetry (TLD). The radiation doses were measured using thermoluminescent dosimeters of LiF:Mg,Ti (TLD 100) and a dog phantom made with a plastic container, proportional to the dog size, fulfilled with water. (Author)

  13. Use of computational simulation for evaluation of 3D printed phantoms for application in clinical dosimetry

    International Nuclear Information System (INIS)

    Valeriano, Caio César Santos

    2017-01-01

    The purpose of a phantom is to represent the change in the radiation field caused by absorption and scattering in a given tissue or organ of interest. Its geometrical characteristics and composition should be as close as possible to the values associated with its natural analogue. Anatomical structures can be transformed into 3D virtual objects by medical imaging techniques (e.g. Computed Tomography) and printed by rapid prototyping using materials, for example, polylactic acid. Its production for specific patients requires fulfilling requirements such as geometric accuracy with the individual's anatomy and tissue equivalence, so that usable measurements can be made, and be insensitive to the radiation effects. The objective of this work was to evaluate the behavior of 3D printed materials when exposed to different photon beams, with emphasis on the quality of radiotherapy (6 MV), aiming its application in clinical dosimetry. For this, 30 thermoluminescent dosimeters of LiF:Mg,Ti were used. The equivalence between the PMMA and the printed PLA for the thermoluminescent response of 30 dosimeters of CaSO 4 : Dy was also analyzed. The irradiations with radiotherapy photon beams were simulated using the Eclipse TM treatment planning system,with the Anisotropic Analytical Algorithm and the Acuros ® XB Advanced Dose Calculation algorithm. In addition to the use of Eclipse TM and dosimetric tests, computational simulations were realized using the MCNP5 code. Simulations with the MCNP5 code were performed to calculate the attenuation coefficient of printed plates exposed to different radiodiagnosis X-rays qualities and to develop a computational model of 3D printed plates. (author)

  14. Dosimetry evaluation of SAVI-based HDR brachytherapy for partial breast irradiation

    Directory of Open Access Journals (Sweden)

    Manoharan Sivasubramanian

    2010-01-01

    Full Text Available Accelerated partial breast irradiation (APBI with high dose rate (HDR brachytherapy offers an excellent compact course of radiation due to its limited number of fractions for early-stage carcinoma of breast. One of the recent devices is SAVI (strut-adjusted volume implant, which has 6, 8 or 10 peripheral source channels with one center channel. Each channel can be differentially loaded. This paper focuses on the treatment planning, dosimetry and quality assurance aspects of HDR brachytherapy implant with GammaMed Plus HDR afterloader unit. The accelerated PBI balloon devices normally inflate above 35 cc range, and hence these balloon type devices cannot be accommodated in small lumpectomy cavity sizes. CT images were obtained and 3-D dosimetric plans were done with Brachyvision planning system. The 3-D treatment planning and dosimetric data were evaluated with planning target volume (PTV_eval V90, V95, V150, V200 skin dose and minimum distance to skin. With the use of the SAVI 6-1 mini device, we were able to accomplish an excellent coverage - V90, V95, V150 and V200 to 98%, 95%, 37 cc (<50 cc volume and 16 cc (<20 cc volume, respectively. Maximum skin dose was between 73% and 90%, much below the prescribed dose of 34 Gy. The minimum skin distance achieved was 5 to 11 mm. The volume that received 50% of the prescribed radiation dose was found to be lower with SAVI. The multi-channel SAVI-based implants reduced the maximum skin dose to markedly lower levels as compared to other modalities, simultaneously achieving best dose coverage to target volume. Differential-source dwell-loading allows modulation of the radiation dose distribution in symmetric or asymmetric opening of the catheter shapes and is also advantageous in cavities close to chest wall.

  15. Biology versus engineering: the TMI accident as a case study in problems of dosimetry

    International Nuclear Information System (INIS)

    Aamodt, N.O.

    2000-01-01

    Contradictions between official results of studying impact on the environment arising from the Three-Mile-Island (TMI) accident in 1979 and scarce information about biological objects irradiation years later are considered. It is shown that some populations (public and animals) underwent radiation exposure by several orders exceeding the previously calculated doses, which is confirmed by cytogenetic and immune tests. The use of meteorological models, which do not consider complicated topography, gives rise to incorrect results. The situation that took shape around TMI provides a unique potentiality for biological dosimetry to demonstrate its efficiency and advantages in technical reconstruction of radiation exposure doses [ru

  16. Numerical analysis for complex thermoluminiscence glow curves.Application to the study of LiF: Ti, Mg and its in radiation dosimetry

    International Nuclear Information System (INIS)

    Gomez Ros, J.M.

    1989-01-01

    A method for the numerical analysis of complex termoluminiscence glow curves based in a modified Marquard Levenberg minimization algorithm is presented. Differents analytical expresions are employed for the individual glow peaks in the cases of first, second and mixed order kinetics, developping aproximated expresions for everyone. These procedures are applied to the caracterization of Lithium Fluoride studying the kinetic order of peaks IV and V. The results obtained permits an interpretation of the complex isothermal decay observed at 165 0 C compatible whith first order kinetics process for both peaks. The aplication to thermoluminiscent dosimetry (TLD) is also described. Other numerical methods are specifically developped to operate whith LiF 8TLD-100) in specific dosimetric aplications of TLD, such environ mental monitoring and mailed dosimetry systems for quality assurance in radiotherapy facilities. The reduction in the minimun detectable dose and the increment in the fiability of the meassurements are some of the advantages obtained over conventional evaluation systems. (Author)

  17. Evaluation of ion chamber dependent correction factors for ionisation chamber dosimetry in proton beams using a Monte Carlo method

    International Nuclear Information System (INIS)

    Palmans, H.; Verhaegen, F.

    1995-01-01

    In the last decade, several clinical proton beam therapy facilities have been developed. To satisfy the demand for uniformity in clinical (routine) proton beam dosimetry two dosimetry protocols (ECHED and AAPM) have been published. Both protocols neglect the influence of ion chamber dependent parameters on dose determination in proton beams because of the scatter properties of these beams, although the problem has not been studied thoroughly yet. A comparison between water calorimetry and ionisation chamber dosimetry showed a discrepancy of 2.6% between the former method and ionometry following the ECHED protocol. Possibly, a small part of this difference can be attributed to chamber dependent correction factors. Indications for this possibility are found in ionometry measurements. To allow the simulation of complex geometries with different media necessary for the study of those corrections, an existing proton Monte Carlo code (PTRAN, Berger) has been modified. The original code, that applies Mollire's multiple scattering theory and Vavilov's energy straggling theory, calculates depth dose profiles, energy distributions and radial distributions for pencil beams in water. Comparisons with measurements and calculations reported in the literature are done to test the program's accuracy. Preliminary results of the influence of chamber design and chamber materials on dose to water determination are presented

  18. Evaluation of ion chamber dependent correction factors for ionisation chamber dosimetry in proton beams using a Monte Carlo method

    Energy Technology Data Exchange (ETDEWEB)

    Palmans, H. [Ghent Univ. (Belgium). Dept. of Biomedical Physics; Verhaegen, F.

    1995-12-01

    In the last decade, several clinical proton beam therapy facilities have been developed. To satisfy the demand for uniformity in clinical (routine) proton beam dosimetry two dosimetry protocols (ECHED and AAPM) have been published. Both protocols neglect the influence of ion chamber dependent parameters on dose determination in proton beams because of the scatter properties of these beams, although the problem has not been studied thoroughly yet. A comparison between water calorimetry and ionisation chamber dosimetry showed a discrepancy of 2.6% between the former method and ionometry following the ECHED protocol. Possibly, a small part of this difference can be attributed to chamber dependent correction factors. Indications for this possibility are found in ionometry measurements. To allow the simulation of complex geometries with different media necessary for the study of those corrections, an existing proton Monte Carlo code (PTRAN, Berger) has been modified. The original code, that applies Mollire`s multiple scattering theory and Vavilov`s energy straggling theory, calculates depth dose profiles, energy distributions and radial distributions for pencil beams in water. Comparisons with measurements and calculations reported in the literature are done to test the program`s accuracy. Preliminary results of the influence of chamber design and chamber materials on dose to water determination are presented.

  19. ESR Dosimetry

    International Nuclear Information System (INIS)

    Baffa, Oswaldo; Rossi, Bruno; Graeff, Carlos; Kinoshita, Angela; Chen Abrego, Felipe; Santos, Adevailton Bernardo dos

    2004-01-01

    ESR dosimetry is widely used for several applications such as dose assessment in accidents, medical applications and sterilization of food and other materials. In this work the dosimetric properties of natural and synthetic Hydroxyapatite, Alanine, and 2-Methylalanine are presented. Recent results on the use of a K-Band (24 GHz) ESR spectrometer in dosimetry are also presented

  20. Retrospective dosimetry: Dose evaluation using unheated and heated quartz from a radioactive waste storage building

    DEFF Research Database (Denmark)

    Jain, M.; Bøtter-Jensen, L.; Murray, A.S.

    2002-01-01

    In the assessment of dose received from a nuclear accident, considerable attention has been paid to retrospective dosimetry using heated materials such as household ceramics and bricks. However, unheated materials such as mortar and concrete are more commonly found in industrial sites...

  1. Practical neutron dosimetry at high energies

    International Nuclear Information System (INIS)

    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

  2. Experimental Study of In-vivo Dosimetry Using Glass Rod Dosimeters to Minimize the Initialization

    Science.gov (United States)

    Jeon, Hosang; Nam, Jiho; Lee, Jayoung; Lee, Juhye; Park, Dahl; Kim, Wontaek; Ki, Yongkan; Kim, Donghyun

    2018-03-01

    In-vivo dosimetry, in which small detector elements are attached to a patient's body, is an important technique for directly evaluating radiation treatment doses. The glass rod dosimeter (GRD) possesses several advantages over alternatives, which makes it one of the most useful detectors for in-vivo dosimetry. However, because the GRD initialization process requires a prolonged exposure at very high temperatures, as well as subsequent gradual quenching, each measurement takes approximately a day to complete. Therefore, we investigated the reliability of a GRD used repeatedly without initialization processes to improve efficiency. Ten doses of 0.5 Gy were delivered and read using three GRD elements. Then, the same procedure was performed for doses of 1.0 Gy. A readout error of less than 2% was maintained for up to three irradiation doses. However, the fluctuations in the readout data increased significantly as the number of irradiation doses increased. In addition, we discovered that the combined uncertainty of the readouts was influenced more heavily by the cumulative amount of irradiation than it was by the number of doses. Our results should provide guidance for accurate and efficient GRD use.

  3. Study of film dosimetry for radiotherapy with Gafchromic-RTQ plates

    International Nuclear Information System (INIS)

    Diaz Moreno, Rogelio Manuel; Lara Mas, Elier; Alfonso Laguardia, Rodolfo

    2009-01-01

    Film dosimetry allows quality control processes (CC) for advanced radiotherapy treatments, not achievable with other types of systems dosimetry, as is the determination of two-dimensional dose distribution provided with the planned treatment in selected planes. The aim of this work was to establish the possibilities of making this type of CC with the means available in the INOR. Plates were used radiochromic Gafchromic-RTQ, for quality control, which irradiated with Elekta Precise linear accelerator, according to the test planning developed in the treatment planning system Precise Plan. Were used as image processing software the Mephysto mc2, PTW, and routines scheduled at home on Matlab. Was prepared calibration curve Dose-response for these plates, and applied this calibration curve at other boards with known radiation dose to estimate proximity of the dose obtained through calibration. Other tests were performed to determine the conditions of repeatability and optimal parameters of the process. Conditions were established that are obtained more reliable , the which are lower than those reported Gafchromic-EBT plates, especially designed quantitative dosimetric purposes, but in certain ranges allow evaluate the of a plan with an acceptable degree of approximation. (author)

  4. Dosimetric evaluation of the Fricke gel dosimeter using the spectrophotometric technique for application in electron and neutron dosimetry

    International Nuclear Information System (INIS)

    Mangueira, Thyago Fressatti

    2011-01-01

    The main dosimetric characteristics of the Fricke Xylenol Gel (FXG) solution were established for further application in the measurement of dose distribution of clinical electron fields. The dose-response curves of the FXG in a thermal neutron field were also evaluated for application in Boron Neutron Capture Therapy (BNCT) and industrial electron fields. The standard reading technique was the spectrophotometry. For clinical fields the intra and inter-batch reproducibility of FXG solution are better than 1.4% and 5.1%, respectively. The optical response presents a linear behavior for doses ranging from 0.2 to 40 Gy independently of the electron energy and the dose rate in the studied ranges. Due to the effects of the FXG natural oxidation, the optimum elapsed time between FXG preparation and irradiation was established as 24h. The behavior of the dose-response curve does not change the obtained absorbance values relative to the non-irradiated dosimeter response during the studied period. The dose-response curve to industrial electron beam presented an exponential decreasing behavior. The optical response to thermal neutrons beam presented a linear behavior for the studied dose range. According to the obtained results to the different radiation fields studied it was not observed changes in the wavelength of the typical bands of the absorption spectrum radiation induced. Additional tests were performed with FXG solution to verify the viability and application of FXG dosimetry on intracavitary brachytherapy using digital photographic imaging. The excellent performance of the FXG dosimeter indicates that this dosimeter may be applied to tri-dimensional dose evaluation in radiotherapy treatments using electrons and neutron beams. (author)

  5. Dosimetric evaluation of the Fricke gel dosimeter using the spectrophotometric technique for application in electron and neutron dosimetry

    International Nuclear Information System (INIS)

    Mangueira, Thyago Fressatti

    2009-01-01

    In this work the main dosimetric characteristics of the Fricke Xylenol Gel (FXG) solution were established for further application in the measurement of dose distribution of clinical electron fields. The dose-response curves of the FXG in a neutron field were also evaluated for the research in Boron Neutron Capture Therapy (BNCT) and industrial electron fields. The standard reading technique was the spectrophotometric. For the clinical field, the intra and inter-batch reproducibility are better than 1.4% and 5.1 %, respectively, the response presents a linear behavior for doses ranging from 0.2 to 40 Gy independently of the energy and the dose rate in the studied ranges. Due to the effects of the FXG natural oxidation, the optimum elapsed time between FXG preparation and irradiation was established as 24h period and the behavior of the dose-response curve of the FXG using the variation in the absorbance relative to the non-irradiated dosimeter as a basis during the whole studied period were not altered. The dose-response to the industrial electron beam presented an exponential decreasing behavior and the neutron beam for research in BNCT presented a linear behavior for the complete studied dose range. According to the obtained results for the different types of radiation studied for the FXG, there was no change in the position of the characteristic bands of the absorption spectrum due to the interaction of these radiation types. Additional tests were performed to determine the digital photographic imaging of FXG analyses viability and the application of FXG dosimetry on intracavitary brachytherapy. The good performance of the FXG dosimeter in the tests that were carried out indicates that this dosimeter may be applied to the tri-dimensional dose evaluation in radiotherapic treatments using electrons and neutron beams. (author)

  6. Studies of aluminium nitride ceramics for application in UV dosimetry

    DEFF Research Database (Denmark)

    Trinkler, L.; Bøtter-Jensen, L.; Christensen, P.

    2000-01-01

    The study is reported of the ceramic material AlN-Y2O3 as a potential luminescence dosemeter for the detection of UV radiation. Both the thermoluminescence and the optically stimulated luminescence properties of the material have been studied after exposure to UV radiation and compared with those...... of the widely used dosemeter material Al2O3:C. It has been shown that AlN-Y2O3 ceramics exhibit three orders of magnitude higher sensitivity to UV radiation than does Al2O3,:C over a broad spectral region. The thermoluminescence from AlN-Y2O3 is characterised by linear dose dependence over a wide range...

  7. Studies of aluminium nitride ceramics for application in UV dosimetry

    DEFF Research Database (Denmark)

    Trinkler, L.; Bøtter-Jensen, L.; Christensen, P.

    2000-01-01

    The study is reported of the ceramic material AlN-Y2O3 as a potential luminescence dosemeter for the detection of UV radiation. Both the thermoluminescence and the optically stimulated luminescence properties of the material have been studied after exposure to UV radiation and compared with those...... of the widely used dosemeter material Al2O3:C. It has been shown that AlN-Y2O3 ceramics exhibit three orders of magnitude higher sensitivity to UV radiation than does Al2O3,:C over a broad spectral region. The thermoluminescence from AlN-Y2O3 is characterised by linear dose dependence over a wide range....... The fading characteristics of the UV-induced thermoluminescence and optically stimulated luminescence signals with storage time at room temperature were found to be a drawback, but still lower than those induced after exposure to ionising radiation....

  8. Evaluation of tissue-equivalent materials to be used as human brain tissue substitute in dosimetry for diagnostic radiology

    International Nuclear Information System (INIS)

    Ferreira, C.C.; Ximenes Filho, R.E.M.; Vieira, J.W.; Tomal, A.; Poletti, M.E.; Garcia, C.A.B.; Maia, A.F.

    2010-01-01

    Tissue-equivalent materials to be used as substitutes for human brain tissue in dosimetry for diagnostic radiology have been investigated in terms of calculated total mass attenuation coefficient (μ/ρ), calculated mass energy-absorption coefficient (μ en /ρ) and absorbed dose. Measured linear attenuation coefficients (μ) have been used for benchmarking the calculated total mass attenuation coefficient (μ/ρ). The materials examined were bolus, nylon (registered) , orange articulation wax, red articulation wax, PMMA (polymethylmethacrylate), bees wax, paraffin I, paraffin II, pitch and water. The results show that water is the best substitute for brain among the materials investigated. The average percentage differences between the calculated μ/ρ and μ en /ρ coefficients for water and those for brain were 1.0% and 2.5%, respectively. Absorbed doses determined by Monte Carlo methods confirm water as being the best brain substitute to be used in dosimetry for diagnostic radiology, showing maximum difference of 0.01%. Additionally this study showed that PMMA, a material often used for the manufacturing of head phantoms for computed tomography, cannot be considered to be a suitable substitute for human brain tissue in dosimetry.

  9. Use of thermoluminescent dosimetry in gamma radiation fields studies

    International Nuclear Information System (INIS)

    Carron, W.

    1987-01-01

    The depth-dose curves for gamma rays in material of interest to agronomy were obtained using lithium fluoride thermoluminescent dosimeters. The dose conversion factors for LiF were determined from curves of the absorved dose versus depth in water, wood and soil. Mathematics equations were chosen to best fit these curves. In the view of the results we came to the conclusion that in the studied materials the absorved radiation dose presents a great variation to the depth and could be correlated through of the exponential regression. (author)

  10. Lactose and ''tris'' lyoluminescence dosimetry systems and ESR correlation studies

    International Nuclear Information System (INIS)

    Oommen, I.K.; Nambi, K.S.V.; Sengupta, S.; Rao, T.K.G.; Ravikumar, M.

    1989-01-01

    Lyoluminescence (LL) dosimeters have been developed using lactose monohydrate (disaccharide) and tris(hydroxymethyl)aminomethane (''Tris'') systems and attempts have been made to understand the LL mechanism through ESR correlation studies. Tris LL dosimeter has a γ-ray sensitivity with a linear response in the absorbed-dose range 0.05-200 Gy (5-2 x 10 4 rad), while the lactose response extends to a higher range from 1 to 10 4 Gy (10 2 -10 6 rad). The LL output of lactose and Tris did not show any appreciable decay for a period of 6 months after irradiation. ESR measurements show that free-radical concentration in both the systems increases with γ-ray dose in the range 10 2 -10 5 Gy. The minimum dose required to measure the radiation-induced ESR signal for Tris is ∼ 500 Gy, the dose at which the LL output saturates, while lactose shows a radiation-induced ESR signal right at the minimum dose where LL could be detected. The estimated spin density on the radical carbon atom is 0.7. ESR signal stabilities of lactose and Tris were also studied. Lactose did not show any appreciable ESR decay for a period of 3 months after irradiation, while, for Tris, one of the radicals showed a decay of 45% for the same period. (author)

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

    Science.gov (United States)

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

    2015-12-01

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

  12. EURISOL Multimegawatt Target Unit - MAFF Configuration: Dosimetry and Activation Studies

    CERN Document Server

    Luis, R; Kadi, Y; Tecchio, L; Kharoua, C; Vaz, P; Ene, D; David, J C; Goncalves, I F; Rocca, R; Romanets, Y; Negoita, F

    2011-01-01

    The EURopean Isotope Separation On-Line Radioactive Ion Beam (EURISOL) project aims at building a facility to produce radioactive ion beams with intensities two to three orders of magnitude higher than those presently available. A 4-MW (1-GeV, 4-mA) proton beam hits a liquid mercury converter, generating, by spallation reactions, high neutron fluxes that induce fission in surrounding fissile targets. In this work, Monte Carlo calculations of dose rate and activation were carried out to identify the necessary shielding and access restrictions for each section of the facility, including maintenance, storage, and remote control spaces. These calculations allowed an optimization of the materials chosen for the assembly, based on the radioprotection issues, while taking into account the desired performance of the system. The results of the design studies indicate that the intended performance parameters (namely neutron fluxes, fission rates, and easy fission target manipulation) of the EURISOL multimegawatt target...

  13. Occupational dose measurement in interventional cardiology, dosimetry comparison study

    International Nuclear Information System (INIS)

    Ahmad, A.M.A.

    2008-05-01

    The number of cardiology interventional procedures has significantly increased recently. This is due to the reliability of the diagnostic equipment to diagnose many heart disease. In the procedures the x-ray used results in increasing radiation doses to the staff. The cardiologists and other staff members in interventional cardiology are usually working close to the area under examination and receive the dose primarily from scattered radiation from the patient. Therefore workers in interventional cardiology are expected to receive high doses. This study overviews the status of occupational exposure at the three cardiology centers at three different hospitals in Khartoum compared with that received by workers at other medical practices (radiotherapy, nuclear medicine and diagnostic radiology) in the Institute of Nuclear and Technology (INMO) at El Gezira. The TLD Harshaw 6600 reader was used in the assessment of effective dose for Hp (10). Two TLDs were used by each worker at the three cardiology centres, one worn under a protective apron and the other worn outside and above the apron as specified by the ICRP. Each worker at the other sections was facilitated with one dosimeter to be worn on the chest. The annual doses received by 14 cardiologists, 13 nurses and 9 technologists at the three cardiology centres were in the range: (0.84-4.77), (0.15-2.08), (0.32-1.10) mSv respectively. In the INMO the annual doses received by 7 doctors, 5 nurses and 14 technologists were in the range: (0.12-0.51), (0.11-0.65), (0.03-1.39) mSv respectively. The results showed that the annual doses received by the workers do not exceed 20 mSv. The study also indicated that doses received by workers in interventional cardiology, in particular the cardiologists are high compared to that received at the other medical sections.(Author)

  14. Infants and young children modeling method for numerical dosimetry studies: application to plane wave exposure

    Science.gov (United States)

    Dahdouh, S.; Varsier, N.; Nunez Ochoa, M. A.; Wiart, J.; Peyman, A.; Bloch, I.

    2016-02-01

    Numerical dosimetry studies require the development of accurate numerical 3D models of the human body. This paper proposes a novel method for building 3D heterogeneous young children models combining results obtained from a semi-automatic multi-organ segmentation algorithm and an anatomy deformation method. The data consist of 3D magnetic resonance images, which are first segmented to obtain a set of initial tissues. A deformation procedure guided by the segmentation results is then developed in order to obtain five young children models ranging from the age of 5 to 37 months. By constraining the deformation of an older child model toward a younger one using segmentation results, we assure the anatomical realism of the models. Using the proposed framework, five models, containing thirteen tissues, are built. Three of these models are used in a prospective dosimetry study to analyze young child exposure to radiofrequency electromagnetic fields. The results lean to show the existence of a relationship between age and whole body exposure. The results also highlight the necessity to specifically study and develop measurements of child tissues dielectric properties.

  15. Infants and young children modeling method for numerical dosimetry studies: application to plane wave exposure

    International Nuclear Information System (INIS)

    Dahdouh, S; Wiart, J; Bloch, I; Varsier, N; Nunez Ochoa, M A; Peyman, A

    2016-01-01

    Numerical dosimetry studies require the development of accurate numerical 3D models of the human body. This paper proposes a novel method for building 3D heterogeneous young children models combining results obtained from a semi-automatic multi-organ segmentation algorithm and an anatomy deformation method. The data consist of 3D magnetic resonance images, which are first segmented to obtain a set of initial tissues. A deformation procedure guided by the segmentation results is then developed in order to obtain five young children models ranging from the age of 5 to 37 months. By constraining the deformation of an older child model toward a younger one using segmentation results, we assure the anatomical realism of the models. Using the proposed framework, five models, containing thirteen tissues, are built. Three of these models are used in a prospective dosimetry study to analyze young child exposure to radiofrequency electromagnetic fields. The results lean to show the existence of a relationship between age and whole body exposure. The results also highlight the necessity to specifically study and develop measurements of child tissues dielectric properties. (paper)

  16. Detailed urethral dosimetry in the evaluation of prostate brachytherapy-related urinary morbidity

    International Nuclear Information System (INIS)

    Allen, Zachariah A.; Merrick, Gregory S.; Butler, Wayne M.; Wallner, Kent E.; Kurko, Brian; Anderson, Richard L.; Murray, Brian C.; Galbreath, Robert W.

    2005-01-01

    Purpose: To evaluate the relationship between urinary morbidity after prostate brachytherapy and urethral doses calculated at the base, midprostate, apex, and urogenital diaphragm. Methods and Materials: From February 1998 through July 2002, 186 consecutive patients without a prior history of a transurethral resection underwent monotherapeutic brachytherapy (no supplemental external beam radiation therapy or androgen deprivation therapy) with urethral-sparing techniques (average urethral dose 100%-140% minimum peripheral dose) for clinical T1c-T2b (2002 AJCC) prostate cancer. The median follow-up was 45.5 months. Urinary morbidity was defined by time to International Prostate Symptom Score (IPSS) resolution, maximum increase in IPSS, catheter dependency, and the need for postimplant surgical intervention. An alpha blocker was initiated approximately 2 weeks before implantation and continued at least until the IPSS returned to baseline. Evaluated parameters included overall urethral dose (average and maximum), doses to the base, midprostate, apex, and urogenital diaphragm, patient age, clinical T stage, preimplant IPSS, ultrasound volume, isotope, and D90 and V100/150/200. Results: Of the 186 patients, 176 (94.6%) had the urinary catheter permanently removed on the day of implantation with only 1 patient requiring a urinary catheter >5 days. No patient had a urethral stricture and only 2 patients (1.1%) required a postbrachytherapy transurethral resection of the prostate (TURP). For the entire cohort, IPSS on average peaked 2 weeks after implantation with a mean and median time to IPSS resolution of 14 and 3 weeks, respectively. For the entire cohort, only isotope predicted for IPSS resolution, while neither overall average prostatic urethra nor segmental urethral dose predicted for IPSS resolution. The maximum postimplant IPSS increase was best predicted by preimplant IPSS and the maximum apical urethral dose. Conclusions: With the routine use of prophylactic alpha

  17. Alanine-ESR dosimetry for radiotherapy IAEA experience

    International Nuclear Information System (INIS)

    Mehta, K.; Girzikowsky, R.; )

    1997-01-01

    At present, the most commonly used transfer dosimeters for radiotherapy applications are TL dosemeters. They are being used for intercomparison between SSDLs (about 70) and the IAEA dosimetry laboratory. However, there are some undesirable characteristics of this dosimetry system. We have a study in progress at the IAEA to evaluate the alanine-ESR systems as an alternative to TLDs. There are several desirable qualities which make alanine an attractive dosemeter. Preliminary data suggest that the alanine-ESR dosimetry system has the potential to replace TLDs for intercomparison amongst SSDLs in the therapy-level dose regions. (Author)

  18. Prediction and evaluation of route dependent dosimetry of BPA in rats at different life stages using a physiologically based pharmacokinetic model

    International Nuclear Information System (INIS)

    Yang, Xiaoxia; Doerge, Daniel R.; Fisher, Jeffrey W.

    2013-01-01

    Bisphenol A (BPA) has received considerable attention throughout the last decade due to its widespread use in consumer products. For the first time a physiologically based pharmacokinetic (PBPK) model was developed in neonatal and adult rats to quantitatively evaluate age-dependent pharmacokinetics of BPA and its phase II metabolites. The PBPK model was calibrated in adult rats using studies on BPA metabolism and excretion in the liver and gastrointestinal tract, and pharmacokinetic data with BPA in adult rats. For immature rats the hepatic and gastrointestinal metabolism of BPA was inferred from studies on the maturation of phase II enzymes coupled with serum time course data in pups. The calibrated model predicted the measured serum concentrations of BPA and BPA conjugates after administration of 100 μg/kg of d6-BPA in adult rats (oral gavage and intravenous administration) and postnatal days 3, 10, and 21 pups (oral gavage). The observed age-dependent BPA serum concentrations were partially attributed to the immature metabolic capacity of pups. A comparison of the dosimetry of BPA across immature rats and monkeys suggests that dose adjustments would be necessary to extrapolate toxicity studies from neonatal rats to infant humans. - Highlights: • A PBPK model predicts the kinetics of bisphenol A (BPA) in young and adult rats. • BPA metabolism within enterocytes is required for fitting of oral BPA kinetic data. • BPA dosimetry in young rats is different than adult rats and young monkeys

  19. Radiological Protection Dosimetry Section report of work done and list of publications during 1981-1982

    International Nuclear Information System (INIS)

    Krishnan, D.; Venkataraman, G.

    1983-01-01

    Radiological Protection Dosimetry Section has as its objective development of dosimetric techniques, theoretical as well as experimental. To this end in view, research and development work on chemical and neutron dosimetry systems, computational dosimetry and dosimetry associated with protection problems is being done. Work is also carried out on radiobiological investigations at cellular level to understand radiation damage and interpret the basis of radiation exposure limits and attendant safety standards. These topics are covered by five groups in the section viz. Neutron Dosimetry, Chemical Dosimetry, Radiation Biophysics, Radium Hazards Evaluation and Control, and Theoretical studies. A brief outline of the activities of each of the above groups is given along with a list of publications for the last two years. (author)

  20. Dosimetry for radiation processing. Final report of the co-ordinated research project on characterization and evaluation of high dose dosimetry techniques for quality assurance in radiation processing

    International Nuclear Information System (INIS)

    2000-06-01

    In many Member States the use of large cobalt-60 gamma ray facilities and electron beam accelerators with beam energies from about 0.1 to 10 MeV for industrial processing continues to increase. For these processes, quality assurance relies on the application of well established dosimetry systems and procedures. This is especially the case for health regulated processes, such as the radiation sterilization of health care products, and the irradiation of food to eliminate pathogenic organisms or to control insect pests. A co-ordinated research project (CRP) was initiated by the IAEA in June 1995. Research contracts and research agreements in areas of high dose dosimetry were initiated to meet these challenges. The major goals of this CRP were to investigate the parameters that influence the response of dosimeters and to develop reference and transfer dosimetry techniques, especially for electron beams of energy less than 4 MeV and for high energy X ray sources (up to 5 MV). These will help to unify the radiation measurements performed by different radiation processing facilities and other high dose dosimetry users in Member States and encourage efforts to obtain traceability to primary and secondary standards laboratories. It will also aim to strengthen and expand the present International Dose Assurance Service (IDAS) provided by the IAEA

  1. Water equivalency evaluation of PRESAGE® dosimeters for dosimetry of Cs-137 and Ir-192 brachytherapy sources

    Science.gov (United States)

    Gorjiara, Tina; Hill, Robin; Kuncic, Zdenka; Baldock, Clive

    2010-11-01

    A major challenge in brachytherapy dosimetry is the measurement of steep dose gradients. This can be achieved with a high spatial resolution three dimensional (3D) dosimeter. PRESAGE® is a polyurethane based dosimeter which is suitable for 3D dosimetry. Since an ideal dosimeter is radiologically water equivalent, we have investigated the relative dose response of three different PRESAGE® formulations, two with a lower chloride and bromide content than original one, for Cs-137 and Ir-192 brachytherapy sources. Doses were calculated using the EGSnrc Monte Carlo package. Our results indicate that PRESAGE® dosimeters are suitable for relative dose measurement of Cs-137 and Ir-192 brachytherapy sources and the lower halogen content PRESAGE® dosimeters are more water equivalent than the original formulation.

  2. Teledosimetry: Personal and Area Dosimetry Control in order to evaluate the risk in real time

    International Nuclear Information System (INIS)

    Galan Montenegro, P.; Macias Jaen, J.; Bodineau Gil, C.; Sanchez Hidalgo, M.

    2004-01-01

    Telemedicine is now an essential part of Health care and so, in addition to the scientific programme in the Carlos Haya Hospital in Malaga, Physics Department is involved into a process of change about the vision as a new Health Centre of XXI Century: Knowledge Hospital, by digital architecture and digitally integrated in its world. The Integrating the Health care Enterprise is the model used in order to get a big grade of relationship between medical images and information system. This change must be done in colaboration between some Departments of our centre, because it is a multidisciplinary task. It is understood that Teledosimetry can be considered as an important part of Telemedicine in the Radiological Protection field for workers and general public. In order to get this objective, the first step since 2000 it has been to prepare the internal hospital network with personal dosimetry information. From here workers in our hospital can obtain their dosimetry information data in more than 300 computers and since 2003, from home too. For access, each one of all have got an user identification and a password and so it can be guaranteed the privacy. We transform dose data reported by CND (Dosimetry National Center) in a big and visible database in PHP4 and Javascript format. This process is marked of problems about all due to the big manipulated information. Our intention is to make a better and friendly control, customisable and in real-time of the information dosimetry by a modular monitoring system of electronic dosimeters by the web. These radiation detectors would be located in representatives places. (Author)

  3. Development, evaluation, and in-vivo validation of two non-invasive methods for quantitation of activity and dosimetry of monoclonal antibodies in humans

    International Nuclear Information System (INIS)

    Hammond, N.D.; Moldofsky, P.J.; Exten, R.E.; Gatenby, R.A.; Broder, G.J.

    1985-01-01

    The authors have applied both a conjugate view imaging method and a first pass study for quantitation of absolute I-131 activity in lesions and normal tissue of patients with colon carcinoma in order to study biological clearance of the I-131 F(ab)'/sub 2/ fragments of mouse monoclonal antibody and the resultant dosimetry. Both methods require a transmission scan for determining patient attenuation and measurement of patient lesion or organ size in the region of interest. The conjugate view method is analyzed for both SPECT and planar imaging. The percent error of both methods relates to lesion size and absolute activity when compared to actual well-counter assayed samples of malignant and normal tissue obtained from CT-guided needle biopsies or surgical specimens. Dosimetric evaluation was based on determination of activity, clearance from computer-generated time-activity curves and lesion or organ volumes from volumetric CT scan data. The dose to the thyroid gland was calculated for one population receiving Lugol's solution 3 days prior and for the other who received Lugol's at the time of administration. Data showed no significant difference in absorbed thyroid dose. Lastly, the absolute uptake of I-131, lesion to background ratios, and the dosimetry data were compared for three different monoclonal antibody fragments

  4. Primary Study about Intensity Signal of Electron Paramagnetic Resonance in vivo Tooth Dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Hoon; Gang, Seo Gon; Kim, Jeong In; Lee, Byung Il [KHNP Radiation Health Institute, Gyeongju (Korea, Republic of)

    2017-04-15

    The signal of Electron Paramagnetic Resonance(EPR) dosimetry system using human tooth has been well introduced as one of the efficient tool to evaluate radiation exposure. But, EPR dosimetry, even in the case of classical in vitro EPR system using tooth sample(measured molars), was regarded as having big signal fluctuation. One of reason for such difficulty in getting accurate intensity was the big effect of organic materials mixed in enamel part of teeth samples. They are mainly caused by the adaptation process of system itself to the movement of measured human subject. Generally, when we measured human teeth in vivo, five of six teeth spectrum were gathered and averaged for real evaluation. The these spectrum are measured under very different environment like angle of external magnet making magnetic filed with teeth(incisor). Random movement of these signals should be considered in different view point to understand and compare each EPR in vivo EPR spectrum. The peak to peak value of obtained five or six in vivo EPR system to get averaged value for final quantity of free radicals in hydroxy apatite crystal construction in enamel part of human teeth looks so randomly changed without regulation. But, in overall view, the EPR signal, especially at no irradiation level, is almost same for every measurement trial which is mainly composed of big noise and very small signal from real free radicals. The peak to peak value of obtained five or six in vivo EPR system to get averaged value for final quantity of free radicals in hydroxy apatite crystal construction in enamel part of human teeth looks so randomly changed without regulation.

  5. Primary Study about Intensity Signal of Electron Paramagnetic Resonance in vivo Tooth Dosimetry

    International Nuclear Information System (INIS)

    Choi, Hoon; Gang, Seo Gon; Kim, Jeong In; Lee, Byung Il

    2017-01-01

    The signal of Electron Paramagnetic Resonance(EPR) dosimetry system using human tooth has been well introduced as one of the efficient tool to evaluate radiation exposure. But, EPR dosimetry, even in the case of classical in vitro EPR system using tooth sample(measured molars), was regarded as having big signal fluctuation. One of reason for such difficulty in getting accurate intensity was the big effect of organic materials mixed in enamel part of teeth samples. They are mainly caused by the adaptation process of system itself to the movement of measured human subject. Generally, when we measured human teeth in vivo, five of six teeth spectrum were gathered and averaged for real evaluation. The these spectrum are measured under very different environment like angle of external magnet making magnetic filed with teeth(incisor). Random movement of these signals should be considered in different view point to understand and compare each EPR in vivo EPR spectrum. The peak to peak value of obtained five or six in vivo EPR system to get averaged value for final quantity of free radicals in hydroxy apatite crystal construction in enamel part of human teeth looks so randomly changed without regulation. But, in overall view, the EPR signal, especially at no irradiation level, is almost same for every measurement trial which is mainly composed of big noise and very small signal from real free radicals. The peak to peak value of obtained five or six in vivo EPR system to get averaged value for final quantity of free radicals in hydroxy apatite crystal construction in enamel part of human teeth looks so randomly changed without regulation.

  6. Photon beam dosimetry with EBT3 film in heterogeneous regions: application to the evaluation of dose-calculation algorithms

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Hyunuk; Han, Youngyih [Sungkyunkwan University, Seoul (Korea, Republic of); Kum, Oyeon [Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of); Park, Byungdo [Samsung Changwon Hospital, Changwon (Korea, Republic of); Sungkyunkwan University, Changwon (Korea, Republic of); Cheong, Kwangho [Hallym University, Anyang (Korea, Republic of)

    2014-12-15

    For a better understanding of the accuracy of state-of-the-art-radiation therapies, 2-dimensional dosimetry in a patient-like environment will be helpful. Therefore, the dosimetry of EBT3 films in non-water-equivalent tissues was investigated, and the accuracy of commercially-used dose calculation algorithms was evaluated with EBT3 measurement. Dose distributions were measured with EBT3 films for an in-house-designed phantom that contained a lung or a bone substitute, i.e., an air cavity (3 x 3 x 3 cm{sup 3}) or teflon (2 x 2 x 2 cm{sup 3} or 3 x 3 x 3 cm{sup 3}), respectively. The phantom was irradiated with 6-MV X-rays with field sizes of 2 x 2, 3 x 3, and 5 x 5 cm{sup 2}. The accuracy of EBT3 dosimetry was evaluated by comparing the measured dose with the dose obtained from Monte Carlo (MC) simulations. A dose-to-bone-equivalent material was obtained by multiplying the EBT3 measurements by the stopping power ratio (SPR). The EBT3 measurements were then compared with the predictions from four algorithms: Monte Carlo (MC) in 0iPlan, acuros XB (AXB), analytical anisotropic algorithm (AAA) in Eclipse, and superposition-convolution (SC) in Pinnacle. For the air cavity, the EBT3 measurements agreed with the MC calculation to within 2% on average. For teflon, the EBT3 measurements differed by 9.297% (±0.9229%) on average from the Monte Carlo calculation before dose conversion, and by 0.717% (±0.6546%) after applying the SPR. The doses calculated by using the MC, AXB, AAA, and SC algorithms for the air cavity differed from the EBT3 measurements on average by 2.174, 2.863, 18.01, and 8.391%, respectively; for teflon, the average differences were 3.447, 4.113, 7.589, and 5.102%. The EBT3 measurements corrected with the SPR agreed with 2% on average both within and beyond the heterogeneities with MC results, thereby indicating that EBT3 dosimetry can be used in heterogeneous media. The MC and the AXB dose calculation algorithms exhibited clinically-acceptable accuracy

  7. Evaluation of plastic materials for range shifting, range compensation, and solid-phantom dosimetry in carbon-ion radiotherapy

    International Nuclear Information System (INIS)

    Kanematsu, Nobuyuki; Koba, Yusuke; Ogata, Risa

    2013-01-01

    Purpose: Beam range control is the essence of radiotherapy with heavy charged particles. In conventional broad-beam delivery, fine range adjustment is achieved by insertion of range shifting and compensating materials. In dosimetry, solid phantoms are often used for convenience. These materials should ideally be equivalent to water. In this study, the authors evaluated dosimetric water equivalence of four common plastics, high-density polyethylene (HDPE), polymethyl methacrylate (PMMA), polyethylene terephthalate (PET), and polyoxymethylene (POM). Methods: Using the Bethe formula for energy loss, the Gottschalk formula for multiple scattering, and the Sihver formula for nuclear interactions, the authors calculated the effective densities of the plastics for these interactions. The authors experimentally measured variation of the Bragg peak of carbon-ion beams by insertion of HDPE, PMMA, and POM, which were compared with analytical model calculations. Results: The theoretical calculation resulted in slightly reduced multiple scattering and severely increased nuclear interactions for HDPE, compared to water and the other plastics. The increase in attenuation of carbon ions for 20-cm range shift was experimentally measured to be 8.9% for HDPE, 2.5% for PMMA, and 0.0% for POM while PET was theoretically estimated to be in between PMMA and POM. The agreement between the measurements and the calculations was about 1% or better. Conclusions: For carbon-ion beams, POM was dosimetrically indistinguishable from water and the best of the plastics examined in this study. The poorest was HDPE, which would reduce the Bragg peak by 0.45% per cm range shift, although with marginal superiority for reduced multiple scattering. Between the two clear plastics, PET would be superior to PMMA in dosimetric water equivalence.

  8. Dosimetry of Low-Energy Beta Radiation

    DEFF Research Database (Denmark)

    Borg, Jette

    Useful techniques and procedures for derermination of absorbed doses from exposure in a low-energy beta radiation were studied and evaluated. The four techniques included were beta spectrometry, extrapolation chamber dosimetry, Monte Carlo (MC) calculations, and exoelectron dosimetry. As a typical...... low-energy beta radiation field a moderated spectrum from a carbon-14 source was used. The measured responce of a Si(Li) detector to photons (bremsstrahlung) showed fine agreemant with the MC calculated photon response, whereas the difference between measured and MC calculated response to electrons...

  9. Evaluation of uncertainties in X radiation metrologic chain in the Secondary Standard Dosimetry Laboratory/IRD-Brazilian CNEN

    International Nuclear Information System (INIS)

    Fonseca Coelho, B.C. da.

    1987-01-01

    The equipment to measure ionizing radiation used in medicine needs appropriate technical qualifications to comply with their purposes and regular calibrations to assure the correct evaluation of associated quantities. By legal requirements, the annual calibration of users' dosemeters is to be done in a Secondary Standard Dosimetry Laboratory (SSDL), andthe SSDL'S standard dosemeters are refered to a Primary Standard Dosimetry (PSDL), establishing a rigourous metrological network. The SSDL network. The SSDL needs to maintain, regularly, a quality control program for short and Long term stability of standard dosemeters. The purpose of the work was to determine the uncertainties associated to technical procedures of X-rays calibration at the SSDL/IRD/IRD. To evaluate the influence of the nine main parameters that can give origin to uncertainties, specific procedures and methods are established, according to international requirements and recomendations. The methods are based on the comparison of the behaviour of the users' dosemeters, with a standard dosemeter in the many measuring conditions set up for the secondary standard used as a reference. The total uncertainty obtained was 1,81% usig a conservative procedure, to protect the users and patients. When needed to transfer the calibration factor and their uncertainty, the procedure used was to determine the uncertainty under the worsst possible operating conditions of the equipment, to obtain a superestimated value. This represents an excellent result for an SDDL of IAEA Network. (autor) [pt

  10. The dosimetry of ionizing radiation

    CERN Document Server

    Bjaerngard, Bengt E; Kase, Kenneth R

    1987-01-01

    The Dosimetry of Ionizing Radiation, Volume II, attempts to fill the need for updated reference material on the field of radiation dosimetry. This book presents some broad topics in dosimetry and a variety of radiation dosimetry instrumentation and its application. The book opens with a chapter that extends and applies the concepts of microdosimetry to biological systems. This is followed by separate chapters on the state- of-the-art equipment and techniques used to determine neutron spectra; studies to determine recombination effects in ionization chambers exposed to high-intensity pulsed ra

  11. Dosimetry methods

    DEFF Research Database (Denmark)

    McLaughlin, W.L.; Miller, A.; Kovacs, A.

    2003-01-01

    Chemical and physical radiation dosimetry methods, used for the measurement of absorbed dose mainly during the practical use of ionizing radiation, are discussed with respect to their characteristics and fields of application.......Chemical and physical radiation dosimetry methods, used for the measurement of absorbed dose mainly during the practical use of ionizing radiation, are discussed with respect to their characteristics and fields of application....

  12. Final Report of the 2nd Ex-Vessel Neutron Dosimetry Installation And Evaluations for Kori Unit 1 Reactor Pressure Vessel

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Byoung Chul; Yoo, Choon Sung; Lee, Sam Lai; Chang, Kee Ok; Gong, Un Sik; Choi, Kwon Jae; Chang, Jong Hwa; Kim, Kwan Hyun; Hong, Joon Wha

    2007-02-15

    This report describes a neutron fluence assessment performed for the Kori Unit 1 pressure vessel beltline region based on the guidance specified in Regulatory Guide 1.190. In this assessment, maximum fast neutron exposures expressed in terms of fast neutron fluence (E>1 MeV) and iron atom displacements (dpa) were established for the beltline region of the pressure vessel. After Cycle 22 of reactor operation, 2nd Ex-Vessel Neutron Dosimetry Program was instituted at Kori Unit 1 to provide continuous monitoring of the beltline region of the reactor vessel. The use of the Ex-Vessel Neutron Dosimetry Program coupled with available surveillance capsule measurements provides a plant specific data base that enables the evaluation of the vessel exposure and the uncertainty associated with that exposure over the service life of the unit. Ex-Vessel Neutron Dosimetry has been evaluated at the conclusion of Cycle 23.

  13. Final report for the 2nd Ex-Vessel Neutron Dosimetry Installations and Evaluations for Yonggwang Unit 2 Reactor Pressure Vessel

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Byoung Chul; Yoo, Choon Sung; Lee, Sam Lai; Gong, Un Sik; Choi, Kwon Jae; Chung, Kyoung Ki; Kim, Kwan Hyun; Chang, Jong Hwa; Ha, Jea Ju

    2008-01-15

    This report describes a neutron fluence assessment performed for the Yonggwang Unit 2 pressure vessel beltline region based on the guidance specified in Regulatory Guide 1.190. In this assessment, maximum fast neutron exposures expressed in terms of fast neutron fluence (E>1 MeV) and iron atom displacements (dpa) were established for the beltline region of the pressure vessel. During Cycle 16 of reactor operation, an Ex-Vessel Neutron Dosimetry Program was instituted at Yonggwang Unit 2 to provide continuous monitoring of the beltline region of the reactor vessel. The use of the Ex-Vessel Neutron Dosimetry Program coupled with available surveillance capsule measurements provides a plant specific data base that enables the evaluation of the vessel exposure and the uncertainty associated with that exposure over the service life of the unit. Ex-Vessel Neutron Dosimetry has been evaluated at the conclusion of Cycle 16.

  14. Final report of the 1st ex-vessel neutron dosimetry installation and evaluations for Yonggwang unit 2 reactor pressure vessel

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Byoung Chul; Yoo, Choon Sung; Lee, Sam Lai; Chang, Kee Ok; Gong, Un Sik; Choi, Kwon Jae; Chang, Jong Hwa; Lim, Nam Jin; Hong, Joon Wha; Cheon, Byeong Jin

    2006-09-15

    This report describes a neutron fluence assessment performed for the Yonggwang unit 2 pressure vessel beltline region based on the guidance specified in regulatory guide 1.190. In this assessment, maximum fast neutron exposures expressed in terms of fast neutron fluence (E>1 MeV) and iron atom displacements (dpa) were established for the beltline region of the pressure vessel. During cycle 15 of reactor operation, an ex-vessel neutron dosimetry program was instituted at Yonggwang unit 2 to provide continuous monitoring of the beltline region of the reactor vessel. The use of the ex-vessel neutron dosimetry program coupled with available surveillance capsule measurements provides a plant specific data base that enables the evaluation of the vessel exposure and the uncertainty associated with that exposure over the service life of the unit. Ex-vessel neutron dosimetry has been evaluated at the conclusion of cycle 15.

  15. Final report for the 3rd Ex-Vessel Neutron Dosimetry Installations and Evaluations for Kori Unit 1 Reactor Pressure Vessel

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Byoung Chul; Yoo, Choon Sung; Lee, Sam Lai (and others)

    2008-03-15

    This report describes a neutron fluence assessment performed for the Kori Unit 1 pressure vessel belt line region based on the guidance specified in Regulatory Guide 1.190. In this assessment, maximum fast neutron exposures expressed in terms of fast neutron fluence (E>1 MeV) and iron atom displacements (dpa) were established for the belt line region of the pressure vessel. After Cycle 23 of reactor operation, 3rd Ex-Vessel Neutron Dosimetry Program was instituted at Kori Unit 1 to provide continuous monitoring of the belt line region of the reactor vessel. The use of the Ex-Vessel Neutron Dosimetry Program coupled with available surveillance capsule measurements provides a plant specific data base that enables the evaluation of the vessel exposure and the uncertainty associated with that exposure over the service life of the unit. Ex-Vessel Neutron Dosimetry has been evaluated at the conclusion of Cycle 24.

  16. Final Report of the 2nd Ex-Vessel Neutron Dosimetry Installation And Evaluations for Yonggwang Unit 1 Reactor Pressure Vessel

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Byoung Chul; Yoo, Choon Sung; Lee, Sam Lai; Gong, Un Sik; Choi, Kwon Jae; Chung, Kyoung Ki; Kim, Kwan Hyun; Chang, Jong Hwa; Ha, Jea Ju

    2008-01-15

    This report describes a neutron fluence assessment performed for the Kori Unit 2 pressure vessel belt line region based on the guidance specified in Regulatory Guide 1.190. In this assessment, maximum fast neutron exposures expressed in terms of fast neutron fluence (E>1 MeV) and iron atom displacements (dpa) were established for the belt line region of the pressure vessel. During Cycle 21 of reactor operation, an Ex-Vessel Neutron Dosimetry Program was instituted at Kori Unit 2 to provide continuous monitoring of the belt line region of the reactor vessel. The use of the Ex-Vessel Neutron Dosimetry Program coupled with available surveillance capsule measurements provides a plant specific data base that enables the evaluation of the vessel exposure and the uncertainty associated with that exposure over the service life of the unit. Ex-Vessel Neutron Dosimetry has been evaluated at the conclusion of Cycle 21.

  17. Evaluation of dosimetry and image quality of computerized tomography abdomen protocols; Avaliacao de dose e qualidade da imagem em protocolos de abdomen em tomografia computadorizada

    Energy Technology Data Exchange (ETDEWEB)

    Maues, Nadine H.P.B.; Alves, Allan F.F.; Bacchim Neto, Fernando A.; Pina, Diana R. [Universidade Estadual Paulista Julio de Mesquita Filho (UNESP), Botucatu, SP (Brazil)

    2016-07-01

    In this study, we evaluate the dosimetry and image quality of computed tomography multislice abdomen protocols for different tube current modulation techniques (ATCM). We used the 16-slice Toshiba Activion CT scanner with the 'SureExposure3D' ATCM system. Thermoluminescent dosimeters were placed inside the anthropomorphic phantom Alderson-Rando for dosimetric assessments. An analytical phantom was used for the objective evaluation of image quality. It is observed that the higher standard deviation technique (SD) has the lowest value of effective dose. The use of different tube current modulation techniques showed significant reduction of radiation doses for the abdomen exams in computed tomography. The ATCM protocols can be an excellent alternative to dose reduction in CT scans, since it does not impair the diagnostic image quality. (author)

  18. Report of results of the tests of evaluation of the operation of service of personal dosimetry of the CNLV

    International Nuclear Information System (INIS)

    Alvarez R, J.T.; Tovar M, V.M.

    2005-11-01

    The ININ realized the evaluation of the service of personal dosimetry in the CNLV, in the categories: IV.- (Photons of high energy of 137 Cs) and the VA.- (Particles beta of 90 Sr/ 90 Y); in the category IV the test was satisfactory, however in the chart 1 has an underestimation a the American Standard HP over the value true conventional of a 9%; for this irregularity it is recommended to revise the procedures of evaluation of the process and the determination of the chart 1 of the HP. In the category VA, the test is also satisfactory, however the results contrasted with the chart 2 and the HP, the values were overestimated in 29% of the true conventional value, and for that problem is recommended to revise the evaluation procedures in contrast with the values determined by the standard HP. (Author)

  19. Space dosimetry

    International Nuclear Information System (INIS)

    Doke, Tadayoshi

    1988-01-01

    Japan will take part in the LML-1 (International Microgravity Laboratory 1) program that is scheduled to be carried out with space shuttles to be launched in 1991. The program will be followed by the LS-J (Space Laboratory-Japan) and IML-2 programs. A reliable dosimetry system is currently required to be established to evaluate the radiations in space. The present article reviews major features of different types of space radiations and requirements of dosimeters for these radiations. The radiations in the space environment consist of: 1) electrons and protons that have been trapped by the terrestrial magnetism, 2) corpuscular, gamma-and X-rays released from the sun, and 3) galactic cosmic rays (corpuscular, gamma-and X-rays). The effects of the trapped radiations will be low if a spacecraft can get through the zone of such radiations in a short period of time. The effects of galactic cosmic rays are much smaller than those of the trapped radiations. A solar flare can give significant contributions to the total radiations received by a spacecraft. An extremely large flare can release a fatal amount of radiations to the crew of a spacecraft. Prediction of such a large flare is of great important for a long trip through the space. Significant improvements should be made on existing dosimeters. (Nogami, K.)

  20. Radiation Dosimetry Study in Dental Enamel of Human Tooth Using Electron Paramagnetic Resonance

    Science.gov (United States)

    De, Tania; Romanyukha, Alex; Pass, Barry; Misra, Prabhakar

    2009-07-01

    Electron paramagnetic resonance (EPR) dosimetry of tooth enamel is used for individual dose reconstruction following radiation accidents. The purpose of this study is to develop a rapid, minimally invasive technique of obtaining a sample of dental enamel small enough to not disturb the structure and functionality of a tooth and to improve the sensitivity of the spectral signals using X-band (9.4 GHz) and Q-band (34 GHz) EPR technique. In this study EPR measurements in X-band were performed on 100 mg isotropic powdered enamel samples and Q-band was performed on 4 mg, 1×1×3 mm enamel biopsy samples. All samples were obtained from discarded teeth collected during normal dental treatment. To study the variation of the Radiation-Induced Signal (RIS) at different orientations in the applied magnetic field, samples were placed in the resonance cavity for Q-band EPR. X-band EPR measurements were performed on 100 mg isotropic powdered enamel samples. In X-band spectra, the RIS is distinct from the "native" radiation-independent signal only for doses >0.5 Gy. Q-band, however, resolves the RIS and "native" signals and improves sensitivity by a factor of 20, enabling measurements in 2-4 mg tooth enamel samples, as compared to 100 mg for X-band. The estimated lower limit of Q-band dose measurement is 0.5 Gy. Q-band EPR enamel dosimetry results in greater sensitivity and smaller sample size through enhanced spectral resolution. Thus, this can be a valuable technique for population triage in the event of detonation of a radiation dispersal device ("dirty" bomb) or other radiation event with massive casualties. Further, the small 4 mg samples can be obtained by a minimally-invasive biopsy technique.

  1. Eleventh ORNL personnel dosimetry intercomparison study, May 22-23, 1985

    Energy Technology Data Exchange (ETDEWEB)

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

    1986-07-01

    The Eleventh Personnel Dosimetry Intercomparison Study was conducted at the Oak Ridge National Laboratory (ORNL) during May 22-23, 1985. Dosimeter badges from 44 participating organizations were mounted on Lucite block phantoms and exposed to four mixed-radiation fields with neutron dose equivalents around 5 mSv and gamma dose equivalents between 0.1 and 0.7 mSv. Results of this study indicated that no participants had difficulty obtaining measurable indication of neutron exposure at the provided dose equivalent levels, and very few had difficulty obtaining indication of gamma exposure at dose equivalents as low as 0.10 mSv. Average neutron results for all dosimeter types were within 20% of reference values with no obvious spectrum dependence. Different dosimeter types (albedo, direct interaction TLD, film, recoil track, and combination albedo-track) with 10 or more reported measurements provided average results within 35% of reference values for all spectra. With regard to precision, about 80% of the reported neutron results had single standard deviations within 10% at the means which indicates that precision is not a problem relative to accuracy for most participants. Average gamma results were greater than reference values by factors of 1.07 to 1.52 for the four exposures with TLD systems being more accurate than film. About 80% of all neutron results and 67% of all gamma results met regulatory standards for measurement accuracy and approximately 70% of all neutron data satisfied national dosimetry accreditation criteria for accuracy plus precision. In general, neutron dosimeter performance observed in this intercomparison was much improved compared to that observed in the prior studies while gamma dosimeter performance was about the same.

  2. Retrospective dosimetry: Dose evaluation using unheated and heated quartz from a radioactive waste storage building

    DEFF Research Database (Denmark)

    Jain, M.; Bøtter-Jensen, L.; Murray, A.S.

    2002-01-01

    and particularly in nuclear installations. These materials contain natural dosemeters Such as quartz. which usually is less sensitive than its heated counterpart. The potential of quartz extracted from mortar in a wall of a low-level radioactive-waste storage facility containing distributed sources of Co-60 and Cs......In the assessment of dose received from a nuclear accident, considerable attention has been paid to retrospective dosimetry using heated materials such as household ceramics and bricks. However, unheated materials such as mortar and concrete are more commonly found in industrial sites...

  3. Luminescence characteristics of dental ceramics for retrospective dosimetry: a preliminary study

    Energy Technology Data Exchange (ETDEWEB)

    Bailiff, I.K.; Correcher, V.; Delgado, A.; Goksu, Y.; Huebner, S

    2002-07-01

    Ceramic materials that are widely employed in dental prosthetics and repairs exhibit luminescent properties. Because of their use in the body, these materials are potentially of interest in situations where retrospective dosimetry for individuals is required but where monitoring was not planned. The luminescent properties of dental ceramics obtained in Germany, Spain and the UK were examined. Linear dose-response characteristics were obtained in the range <100 mGy to 10 Gy using thermoluminescence (TL), optically stimulated luminescence and infrared-stimulated luminescence measurement techniques. Measurements of time-resolved luminescence were also performed to examine the nature of the luminescence recombination under visible (470 nm) and IR (855 nm) stimulation. The results obtained by TL and optically stimulated techniques suggest that there may be deeper traps than previously observed in certain types of dental ceramic. Such traps may be less susceptible to optical and athermal fading than was reported in earlier studies. (author)

  4. Dosimetry in radiobiological studies with the heavy ion beam of the Warsaw cyclotron

    International Nuclear Information System (INIS)

    Kaźmierczak, U.; Banaś, D.; Braziewicz, J.; Czub, J.; Jaskóła, M.; Korman, A.; Kruszewski, M.; Lankoff, A.; Lisowska, H.; Malinowska, A.; Stępkowski, T.; Szefliński, Z.

    2015-01-01

    The aim of this study was to verify various dosimetry methods in the irradiation of biological materials with a 12 C ion beam at the Heavy Ion Laboratory of the University of Warsaw. To this end the number of ions hitting the cell nucleus, calculated on the basis of the Si-detector system used in the set-up, was compared with the number of ion tracks counted in irradiated Solid State Nuclear Track Detectors and with the number of ion tracks detected in irradiated Chinese Hamster Ovary cells processed for the γ-H2AX assay. Tests results were self-consistent and confirmed that the system serves its dosimetric purpose.

  5. Utero-fetal unit and pregnant woman modeling using a computer graphics approach for dosimetry studies.

    Science.gov (United States)

    Anquez, Jérémie; Boubekeur, Tamy; Bibin, Lazar; Angelini, Elsa; Bloch, Isabelle

    2009-01-01

    Potential sanitary effects related to electromagnetic fields exposure raise public concerns, especially for fetuses during pregnancy. Human fetus exposure can only be assessed through simulated dosimetry studies, performed on anthropomorphic models of pregnant women. In this paper, we propose a new methodology to generate a set of detailed utero-fetal unit (UFU) 3D models during the first and third trimesters of pregnancy, based on segmented 3D ultrasound and MRI data. UFU models are built using recent geometry processing methods derived from mesh-based computer graphics techniques and embedded in a synthetic woman body. Nine pregnant woman models have been generated using this approach and validated by obstetricians, for anatomical accuracy and representativeness.

  6. Nuclear medicine radiation dosimetry

    CERN Document Server

    McParland, Brian J

    2010-01-01

    Complexities of the requirements for accurate radiation dosimetry evaluation in both diagnostic and therapeutic nuclear medicine (including PET) have grown over the past decade. This is due primarily to four factors: growing consideration of accurate patient-specific treatment planning for radionuclide therapy as a means of improving the therapeutic benefit, development of more realistic anthropomorphic phantoms and their use in estimating radiation transport and dosimetry in patients, design and use of advanced Monte Carlo algorithms in calculating the above-mentioned radiation transport and

  7. REVIEW: Nuclear medicine dosimetry

    Science.gov (United States)

    Stabin, Michael

    2006-07-01

    A brief overview is provided of the history of the development of internal dose methods for use in nuclear medicine. Basic methods of internal dosimetry and the systems that have been developed for use in nuclear medicine are described. The development of the MIRD system and the International Radiopharmaceutical Dosimetry Symposium series is outlined. The evolution of models and tools for calculating dose estimates is reviewed. Current efforts in developing more patient-specific methods, particularly for use in therapy calculations, development of small scale and microdosimetry techniques, and of relating internal radiation doses to observed biological effects are described and evaluated.

  8. ISDD: A computational model of particle sedimentation, diffusion and target cell dosimetry for in vitro toxicity studies

    Directory of Open Access Journals (Sweden)

    Chrisler William B

    2010-11-01

    g/mL basis and target cell doses on a particle surface area or number basis can be as high as three to six orders of magnitude. As a consequence, in vitro hazard assessments utilizing mass-based exposure metrics have inherently high errors where particle number or surface areas target cells doses are believed to drive response. The gold standard for particle dosimetry for in vitro nanotoxicology studies should be direct experimental measurement of the cellular content of the studied particle. However, where such measurements are impractical, unfeasible, and before such measurements become common, particle dosimetry models such as ISDD provide a valuable, immediately useful alternative, and eventually, an adjunct to such measurements.

  9. ISDD: A computational model of particle sedimentation, diffusion and target cell dosimetry for in vitro toxicity studies

    Science.gov (United States)

    2010-01-01

    doses on a particle surface area or number basis can be as high as three to six orders of magnitude. As a consequence, in vitro hazard assessments utilizing mass-based exposure metrics have inherently high errors where particle number or surface areas target cells doses are believed to drive response. The gold standard for particle dosimetry for in vitro nanotoxicology studies should be direct experimental measurement of the cellular content of the studied particle. However, where such measurements are impractical, unfeasible, and before such measurements become common, particle dosimetry models such as ISDD provide a valuable, immediately useful alternative, and eventually, an adjunct to such measurements. PMID:21118529

  10. Dosimetry studies with TLDs for stereotactic radiation techniques for intraocular tumours

    International Nuclear Information System (INIS)

    Ertl, A.; Schoeggl, A.; Zehetmayer, M.; Kindl, P.; Hartl, R.

    1997-01-01

    Between March 1993 and January 1997, stereotactic radiation techniques were used to irradiate 66 intraocular tumour patients with the Gamma Knife (Leksell Gamma Knife, model B unit) at the University of Vienna, Austria. This study investigates the dosimetry for stereotactic irradiation of ocular structures. For the dosimetry program KULA 4.4, Gamma Knife stereotactic irradiation of the eye represents an extreme frontal skull position. In addition, irradiation of the eye may be performed in the usual supine position in exceptional cases only. With the patient in the prone position, the dose planning program has to calculate with a significantly large number of single-beam extrapolations. In our first experiment we measured the isocentre dose for eight different γ-angle positions, both in prone and supine positions, using TLD measurements in an Alderson head phantom. We found a maximum deviation of ±1.6% using these individually calibrated TLDs. In the second experiment we examined the dose cross profiles for the two most frequently used treatment positions (supine position, γ = 65 deg., and prone position, γ = 140 deg.). For this purpose we implanted a specially designed TLD array into the orbit of a human cadaver head. We found excellent agreement of the dose values measured for the isocentre as well as the posterior part of the eye with orbit with deviations of less than -2.7%. However, for the anterior part of the eye, deviations between computer-generated calculations and the TLD measurements were found to range up to -30%. These differences were noticed both for supine and prone positions. For the Gamma Knife stereotactic irradiation of ocular tumours or pathologies, precautions should be taken to avoid significant underdosage in the anterior part of the radiation field. (author)

  11. Reactor Dosimetry State of the Art 2008

    Science.gov (United States)

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

    2009-08-01

    data, damage correlations. Two-dimensional mapping of the calculated fission power for the full-size fuel plate experiment irradiated in the advanced test reactor / G. S. Chang and M. A. Lillo. The radiation safety information computational center: a resource for reactor dosimetry software and nuclear data / B. L. Kirk. Irradiated xenon isotopic ratio measurement for failed fuel detection and location in fast reactor / C. Ito, T. Iguchi and H. Harano. Characterization of dosimetry of the BMRR horizontal thimble tubes and broad beam facility / J.-P. Hu, R. N. Reciniello and N. E. Holden. 2007 nuclear data review / N. E. Holden. Further dosimetry studies at the Rhode Island nuclear science / R. N. Reciniello ... [et al.]. Characterization of neutron fields in the experimental fast reactor Joyo MK-III core / S. Maeda ... [et al.]. Measuring [symbol]Li(n, t) and [symbol]B(n, [symbol]) cross sections using the NIST alpha-gamma apparatus / M. S. Dewey ... [et al.]. Improvement of neutron/gamma field evaluation for restart of JMTR / Y. Nagao ... [et al.]. Monitoring of the irradiated neutron fluence in the neutron transmutation doping process of HANARO / M.-S. Kim and S.-J. Park.Training reactor VR-l neutron spectrum determination / M. Vins, A. Kolros and K. Katovsky. Differential cross sections for gamma-ray production by 14 MeV neutrons on iron and bismuth / V. M. Bondar ... [et al.]. The measurements of the differential elastic neutron cross-sections of carbon for energies from 2 to 133 ke V / O. Gritzay ... [et al.]. Determination of neutron spectrum by the dosimetry foil method up to 35 Me V / S. P. Simakov ... [et al.]. Extension of the BGL broad group cross section library / D. Kirilova, S. Belousov and Kr. Ilieva. Measurements of neutron capture cross-section for tantalum at the neutron filtered beams / O. Gritzayand V. Libman. Measurements of microscopic data at GELINA in support of dosimetry / S. Kopecky ... [et al.]. Nuclide guide and international chart of

  12. Comparing Hp(3) evaluated from the conversion coefficients from air kerma to personal dose equivalent for eye lens dosimetry calibrated on a new cylindrical PMMA phantom

    Science.gov (United States)

    Esor, J.; Sudchai, W.; Monthonwattana, S.; Pungkun, V.; Intang, A.

    2017-06-01

    Based on a new occupational dose limit recommended by ICRP (2011), the annual dose limit for the lens of the eye for workers should be reduced from 150 mSv/y to 20 mSv/y averaged over 5 consecutive years in which no single year exceeding 50 mSv. This new dose limit directly affects radiologists and cardiologists whose work involves high radiation exposure over 20 mSv/y. Eye lens dosimetry (Hp(3)) has become increasingly important and should be evaluated directly based on dosimeters that are worn closely to the eye. Normally, Hp(3) dose algorithm was carried out by the combination of Hp(0.07) and Hp(10) values while dosimeters were calibrated on slab PMMA phantom. Recently, there were three reports from European Union that have shown the conversion coefficients from air kerma to Hp(3). These conversion coefficients carried out by ORAMED, PTB and CEA Saclay projects were performed by using a new cylindrical head phantom. In this study, various delivered doses were calculated using those three conversion coefficients while nanoDot, small OSL dosimeters, were used for Hp(3) measurement. These calibrations were performed with a standard X-ray generator at Secondary Standard Dosimetry Laboratory (SSDL). Delivered doses (Hp(3)) using those three conversion coefficients were compared with Hp(3) from nanoDot measurements. The results showed that percentage differences between delivered doses evaluated from the conversion coefficient of each project and Hp(3) doses evaluated from the nanoDots were found to be not exceeding -11.48 %, -8.85 % and -8.85 % for ORAMED, PTB and CEA Saclay project, respectively.

  13. Selected radiotherapeutic planning and dosimetry for conservative treatment of early breast cancer. Evaluation and analysis for the dose distribution maps on phantom

    International Nuclear Information System (INIS)

    Ogoh, Etsuyo

    1997-01-01

    It is important for radiotherapy in breast conservative treatment to equalize dose distribution for a conserved breast, as well as to reduce radiation dose for the ipsilateral lung and contralateral breast. To obtain the optimal method of radiotherapy, I carried out an experimental study using an original hand-made phantom which was made from Mix-Dp and cork. In these experiments, I evaluated relative dose using the film dosimetry method and absolute dose using TLD, with three methods as a function of wedge filter angle; opposed pair method, non-opposed pair method, and half-field block method. As a result, we concluded that a non-opposed pair method with a 15-degree wedge filter seems to be optimal for the 4MV-Xray Linac in our institute. (author)

  14. Evaluation of the UF/NCI hybrid computational phantoms for use in organ dosimetry of pediatric patients undergoing fluoroscopically guided cardiac procedures

    Science.gov (United States)

    Marshall, Emily L.; Borrego, David; Tran, Trung; Fudge, James C.; Bolch, Wesley E.

    2018-03-01

    Epidemiologic data demonstrate that pediatric patients face a higher relative risk of radiation induced cancers than their adult counterparts at equivalent exposures. Infants and children with congenital heart defects are a critical patient population exposed to ionizing radiation during life-saving procedures. These patients will likely incur numerous procedures throughout their lifespan, each time increasing their cumulative radiation absorbed dose. As continued improvements in long-term prognosis of congenital heart defect patients is achieved, a better understanding of organ radiation dose following treatment becomes increasingly vital. Dosimetry of these patients can be accomplished using Monte Carlo radiation transport simulations, coupled with modern anatomical patient models. The aim of this study was to evaluate the performance of the University of Florida/National Cancer Institute (UF/NCI) pediatric hybrid computational phantom library for organ dose assessment of patients that have undergone fluoroscopically guided cardiac catheterizations. In this study, two types of simulations were modeled. A dose assessment was performed on 29 patient-specific voxel phantoms (taken as representing the patient’s true anatomy), height/weight-matched hybrid library phantoms, and age-matched reference phantoms. Two exposure studies were conducted for each phantom type. First, a parametric study was constructed by the attending pediatric interventional cardiologist at the University of Florida to model the range of parameters seen clinically. Second, four clinical cardiac procedures were simulated based upon internal logfiles captured by a Toshiba Infinix-i Cardiac Bi-Plane fluoroscopic unit. Performance of the phantom library was quantified by computing both the percent difference in individual organ doses, as well as the organ dose root mean square values for overall phantom assessment between the matched phantoms (UF/NCI library or reference) and the patient

  15. Personalized Monte Carlo dosimetry for the planning and evaluation of internal radiotherapy treatments: development and application to selective internal radiotherapy (SIRT)

    International Nuclear Information System (INIS)

    Petitguillaume, Alice

    2014-01-01

    Medical techniques in full expansion arousing high therapeutic expectations, targeted radionuclide therapies (TRT) consist of administering a radiopharmaceutical to selectively treat tumors. Nowadays, the activity injected to the patient is generally standardized. However, in order to establish robust dose-effect relationships and to optimize treatments while sparing healthy tissues at best, a personalized dosimetry must be performed, just like actual clinical practice in external beam radiotherapy. In that context, this PhD main objective was to develop, using the OEDIPE software, a methodology for personalized dosimetry based on direct Monte Carlo calculations. The developed method enables to calculate the tridimensional distribution of absorbed doses depending on the patient anatomy, defined from CT or MRI data, and on the patient-specific activity biodistribution, defined from SPECT or PET data. Radiobiological aspects, such as differences in radiosensitivities and repair time constants between tumoral and healthy tissues, have also been integrated through the linear-quadratic model. This methodology has been applied to the selective internal radiation therapy (SIRT) which consists in the injection of 90 Y-microspheres to selectively treat unresectable hepatic cancers. Distributions of absorbed doses and biologically effective doses (BED) along with the equivalent uniform biologically effective doses (EUD) to hepatic lesions have been calculated from 99m Tc-MAA activity distributions obtained during the evaluation step for 18 patients treated at Hopital Europeen Georges Pompidou. Those results have been compared to classical methods used in clinics and the interest of accurate and personalized dosimetry for treatment planning has been investigated. On the one hand, the possibility to increase the activity in a personalized way has been highlighted with the calculation of the maximal activity that could be injected to the patient while meeting tolerance criteria

  16. Hanford internal dosimetry program manual

    Energy Technology Data Exchange (ETDEWEB)

    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.

  17. Hanford internal dosimetry program manual

    International Nuclear Information System (INIS)

    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

  18. Scientific production of the Radioprotection and Dosimetry Institute (IRD): preliminary bibliometric evaluation of the journal articles

    International Nuclear Information System (INIS)

    Gusmao Pedrini, A. de; Universidade do Estado, Rio de Janeiro, RJ; Universidade Santa Ursula, Rio de Janeiro, RJ

    1994-01-01

    A total of 114 articles (1974-1991, this last year the most productive) in 28 periodicals were published. The periodical core production is made up of: Health Physics, Radiation Protection Dosimetry, Radioprotecao e Dosimetria, Radiologia Brasileira. 53% were written in cooperation with 33 institutions. The 155 authors and 376 authorship were mainly in collective and triple-authorship articles. Mean productivity/author was 2.8 articles which is lower than that of Price. The most productivity author produced 14 articles + 19 co-authors in 7 periodicals on environmental radiation protection while 88 authors produced 1 article. The productive elite (12 authors) accounted for 72 articles, 26% above the average according to Lotka, with 111 out of a total of 376 authorships in 20 periodicals. The elite forms an inter departmental communication network with authors who write about environmental, occupational and individual radiation protection. (author). 17 refs, 1 tab

  19. Retrospective dosimetry of Chernobyl liquidators

    International Nuclear Information System (INIS)

    Chumak, V.V.; Bakhanova, E.V.; Sholom, S.V.; Pasalskaya, L.F.; Bouville, A.; Krjuchkov, V.P.

    2000-01-01

    The numerous cohort of Chernobyl liquidators is a very attractive subject for epidemiological follow up due to high levels of exposure, age-gender distribution and availability of patients for medical examination. However, dosimetric information related to this population is incomplete, in many cases the quality of available dose records is doubtful and uncertainties of all dose values are not determined. Naive attempts to evaluate average doses on the basis of such factors as 'distance from the reactor' obviously fail due to large variation of tasks and workplace contamination. Therefore, prior to any sensible consideration of liquidators as a subject of epidemiological study, their doses should be evaluated (reevaluated) using the methods of retrospective dosimetry. Retrospective dosimetry in general got significant development over the last decade. However, most of the retrospective dosimetry techniques are time consuming, expensive and possess sensitivity threshold. Therefore, application of retrospective dosimetry for the needs of epidemiological follow up studies requires development of certain strategy. This strategy depends, of coarse, on the epidemiological design of the study, availability of resources and dosimetric information related to the time of clean up. One of the strategies of application of retrospective dosimetry may be demonstrated on the example of a cohort study with occasional nested case control consideration. In this case, the tools are needed for validation of existing dose records (of not always known quality), screening of the study cohort with express dosimetric method called to determine possible dose ranges, and 'state-of-the-art' assessment of individual doses for selected subjects (cases and controls). Verification of dose records involves analysis of the statistical regularities of dose distributions and detection of possible extraneous admixtures (presumably falsified dose records). This work is performed on impersonified data

  20. Evaluation of [18F]Nifene biodistribution and dosimetry based on whole-body PET imaging of mice.

    Science.gov (United States)

    Constantinescu, Cristian C; Garcia, Adriana; Mirbolooki, M Reza; Pan, Min-Liang; Mukherjee, Jogeshwar

    2013-02-01

    [(18)F]Nifene is a novel radiotracer specific to the nicotinic acetylcholine α4β2 receptor class. In preparation for using this tracer in humans we have performed whole-body PET studies in mice to evaluate the in vivo biodistribution and dosimetry of [(18)F]Nifene. Seven BALB/c mice (3 males, 4 females) received IV tail injections of [(18)F]Nifene and were scanned for 2 h in an Inveon dedicated PET scanner. Each animal also received a high resolution CT scan using an Inveon CT. The CT images were used to draw volume of interest (VOI) on the following organs: brain, large intestine, small intestine, stomach, heart, kidneys, liver, lungs, pancreas, bone, spleen, testes, thymus, uterus and urinary bladder. All organ time activity curves had the decay correction reversed and were normalized to the injected activity. The area under the normalized curves was then used to compute the residence times in each organ. The absorbed doses in mouse organs were computed using the RAdiation Dose Assessment Resource (RADAR) animal models for dose assessment. The residence times in mouse organs were converted to human values using scale factors based on differences between organ and body weights. OLINDA 1.1 software was used to compute the absorbed human doses in multiple organs for both female and male phantoms. The highest mouse residence times were found in urinary bladder, liver, bone, small intestine and kidneys. The largest doses in mice were found in urinary bladder and kidneys for both females and males. The elimination of radiotracer was primarily via kidney and urinary bladder with the urinary bladder being the limiting organ. The projected human effective doses were 1.51E-02 mSv/MBq for the adult male phantom and 1.65E-02 mSv/MBq for the adult female model phantom. This study indicates that the whole-body mouse imaging can be used as a preclinical tool for initial estimation of the absorbed doses of [(18)F]Nifene in humans. Copyright © 2013 Elsevier Inc. All rights

  1. Study of the reliability of the TLDs reader in a Thermoluminescent dosimetry laboratory

    International Nuclear Information System (INIS)

    Silva F, J.C. da; Fonseca, H.G. da

    2006-01-01

    Acting from the beginning of the decade of 80 in a postal program called 'Dentistry Programs' the Institute of Radioprotection and Dosimetry (IRD) it makes an effort supported by the IAEA so that it can determine with security the reference levels for the diverse practices in radiodiagnostic, including the dentistry. The dentistry program that uses 4 TLDs of lithium fluorite (LiF 100) for evaluations of the doses and of the hemirreductor layer, until 1995 it had already verified close of 5529 X-ray equipment. This work accompanies the result of 3 main parameters (arbitrary reading, reference light and noise) of the reader Harshaw marks 5500, when it is used for routine readings of the TLDs that arrive in the dosimetry laboratory for the due ratings. Together with these TLDs 9 previously selected dosemeters of a certain dosemeters lot is placed with a percentage uncertainty of 3% (for 1 standard deviation). before them they were irradiated in an irradiator of Sr90/Y90 with a dose of approximately 5 mGy, they are treated thermally in an oven PTW it marks to 400 grades for 1 hour + 100 grades for 2 hours and 100 grades in 15 minutes after the irradiations. The referred methodology follows a procedure where they are distributed of 3 in 3 the chosen TLDs of the group of the 9, to the beginning, half and at the end among the total quantity of dosemeters read in the reading disk that it can read of a single time 50 dosemeters. Together with this 10 measurements of reference light and noise are made, data that are provided by the reader through the 'softer WinRem'. Finally the obtained results of reference light and noise, its are compared with the maker's recommendations. Already that of the arbitrary reading (average of the 9 TLDs and its uncertainties), it has revealed a reduction in the percentage uncertainty (2 deviations standard / average) with relationship to one of the first results already obtained through the methodology proposal. It has been, also, applied the

  2. TU-E-201-01: Methods for Eye Lens Dosimetry and Studies On Lens Opacities with Interventionists

    Energy Technology Data Exchange (ETDEWEB)

    Rehani, M. [Massachusetts General Hospital (United States)

    2015-06-15

    Madan M. Rehani, Massachusetts General Hospital and Harvard Medical School, Boston Methods for Eye Lens Dosimetry and Studies On Lens Opacities with Interventionalists Radiation induced cataract is a major threat among staff working in interventional suites. Nearly 16 million interventional procedures are performed annually in USA. Recent studies by the principal investigator’s group, primarily among interventional cardiologists, on behalf of the International Atomic Energy Agency, show posterior subcapsular (PSC) changes in the eye lens in 38–53% of main operators and 21–45% of support staff. These changes have potential to lead to cataract in future years, as per information from A-Bomb survivors. The International Commission on Radiological Protection has reduced dose limit for staff by a factor of 7.5 (from 150 mSv/y to 20 mSv/y). With increasing emphasis on radiation induced cataracts and reduction in threshold dose for eye lens, there is a need to implement strategies for estimating eye lens dose. Unfortunately eye lens dosimetry is at infancy when it comes to routine application. Various approaches are being tried namely direct measurement using active or passive dosimeters kept close to eyes, retrospective estimations and lastly correlating patient dose in interventional procedures with staff eye dose. The talk will review all approaches available and ongoing active research in this area, as well as data from surveys done in Europe on status of eye dose monitoring in interventional radiology and nuclear medicine. The talk will provide update on how good is Hp(10) against Hp(3), estimations from CTDI values, Monte Carlo based simulations and current status of eye lens dosimetry in USA and Europe. The cataract risk among patients is in CT examinations of the head. Since radiation induced cataract predominantly occurs in posterior sub-capsular (PSC) region and is thus distinguishable from age or drug related cataracts and is also preventable, actions on

  3. Radiotherapy Based On α Emitting Radionuclides: Geant4 For Dosimetry And Micro-/Nano-Dosimetry

    International Nuclear Information System (INIS)

    Guatelli, Susanna

    2013-01-01

    Possible physics approaches to evaluate the efficacy of TAT are dosimetry, microdosimetry and nanodosimetry. Dosimetry is adequate when mean absorbed dose to a macroscopic target volume is important to understand the biological effect of radiation. General purpose Monte Carlo (MC) codes, based on condensed history approach, are a very useful, cost effective tool to solve dosimetric problems. The condensed history approach is based on the use of multiple scattering theories to calculate the energy losses and angular changes in the direction of the particle. The short α particle range and high LET make the microdosimetric approach more suitable than dosimetry to study TAT from first physics principles, as this approach takes into account the stochastic nature of energy deposition at cellular level

  4. Environmental dosimetry

    International Nuclear Information System (INIS)

    Gold, R.

    1977-01-01

    For more than 60 years, natural radiation has offered broad opportunities for basic research as evidenced by many fundamental discoveries. Within the last decade, however, dramatic changes have occurred in the motivation and direction of this research. The urgent need for economical energy sources entailing acceptably low levels of environmental impact has compelled the applied aspects of our radiation environment to become overriding considerations. It is within this general framework that state-of-the-art environmental dosimetry techniques are reviewed. Although applied motivation and relevance underscores the current milieu for both reactor and environmental dosimetry, a perhaps even more unifying force is the broad similarity of reactor and environmental radiation fields. In this review, a comparison of these two mixed radiation fields is presented stressing the underlying similarities that exist. On this basis, the evolution of a strong inner bond between dosimetry methods for both reactor and environmental radiation fields is described. The existence of this bond will be illustrated using representative examples of observed spectra. Dosimetry methods of particularly high applicability for both of these fields are described. Special emphasis is placed on techniques of high sensitivity and absolute accuracy which are capable of resolving the components of these mixed radiation fields

  5. Radiation exposure and dosimetry in transplant patients due to Nuclear Medicine studies

    International Nuclear Information System (INIS)

    El-Maghraby, T. A. F.; Cairo Univ., Cairo; Camps, J. A. J.; Geleyns, J.; Pauwels, E. K. J.

    2000-01-01

    Organ transplantation is now an accepted method of therapy for treating patients with end stage failure of kidneys, liver, heart or lung. Nuclear Medicine may provide functional data and semi-quantitative parameters. However, one serious factor that hampers the use of nuclear medicine procedures in transplant patients is the general clinical concern about radiation exposure to the patient. This lead the researcher to discuss the effective doses and radiation dosimetry associated with radionuclide procedures used in the management and follow-up of transplant patients. A simple way to place the risk associated with Nuclear Medicine studies in an appropriate context is to compare the dose with that received from more familiar source of exposure such as from a diagnostic X-ray procedure. The radiation dose for the different radiopharmaceuticals used to study transplant organ function ranges between 0.1 and 5.3 mSv which is comparable to X-ray procedures with the exception of 201 Tl and 111 In-antimyosin. Thus Nuclear Medicine studies do not bear a higher radiation risk than the often used X-ray studies in transplant patients

  6. A comprehensive tool for image-based generation of fetus and pregnant women mesh models for numerical dosimetry studies

    International Nuclear Information System (INIS)

    Dahdouh, S; Serrurier, A; De la Plata, J-P; Anquez, J; Angelini, E D; Bloch, I; Varsier, N; Wiart, J

    2014-01-01

    Fetal dosimetry studies require the development of accurate numerical 3D models of the pregnant woman and the fetus. This paper proposes a 3D articulated fetal growth model covering the main phases of pregnancy and a pregnant woman model combining the utero-fetal structures and a deformable non-pregnant woman body envelope. The structures of interest were automatically or semi-automatically (depending on the stage of pregnancy) segmented from a database of images and surface meshes were generated. By interpolating linearly between fetal structures, each one can be generated at any age and in any position. A method is also described to insert the utero-fetal structures in the maternal body. A validation of the fetal models is proposed, comparing a set of biometric measurements to medical reference charts. The usability of the pregnant woman model in dosimetry studies is also investigated, with respect to the influence of the abdominal fat layer. (paper)

  7. A comparative study of some aspects of radiation protection and dosimetry procedures. Pt. 1 and 2

    International Nuclear Information System (INIS)

    Drexler, G.; Goeksu, H.Y.; Johns, T.F.

    1987-10-01

    A study has been made of the procedures used in the Member States of the European Communities for dealing with certain practical and administrative aspects of radiation protection of occupationally exposed persons, and especially of the methods and procedures used in personnel dosimetry. It was found that the different states have adopted quite different methods for dealing with some of these problems, the method chosen seeming to depend on the size of the country and the extent and timing of its involvement with nuclear power developments; but although the different countries have adopted different methods of control, as far as we can judge they have all been reasonably effective in achieving adequate control of occupational exposures. Nevertheless, there are still issues that each country could probably learn and perhaps improve its own procedure by making a more careful study of the way in which other countries deal with these problems. Therefore the study was extended to cover the USA and Japan in order to facilitate such comparisons and improvements. (orig.)

  8. Quantitative performance evaluation of 124I PET/MRI lesion dosimetry in differentiated thyroid cancer

    Science.gov (United States)

    Wierts, R.; Jentzen, W.; Quick, H. H.; Wisselink, H. J.; Pooters, I. N. A.; Wildberger, J. E.; Herrmann, K.; Kemerink, G. J.; Backes, W. H.; Mottaghy, F. M.

    2018-01-01

    The aim was to investigate the quantitative performance of 124I PET/MRI for pre-therapy lesion dosimetry in differentiated thyroid cancer (DTC). Phantom measurements were performed on a PET/MRI system (Biograph mMR, Siemens Healthcare) using 124I and 18F. The PET calibration factor and the influence of radiofrequency coil attenuation were determined using a cylindrical phantom homogeneously filled with radioactivity. The calibration factor was 1.00  ±  0.02 for 18F and 0.88  ±  0.02 for 124I. Near the radiofrequency surface coil an underestimation of less than 5% in radioactivity concentration was observed. Soft-tissue sphere recovery coefficients were determined using the NEMA IEC body phantom. Recovery coefficients were systematically higher for 18F than for 124I. In addition, the six spheres of the phantom were segmented using a PET-based iterative segmentation algorithm. For all 124I measurements, the deviations in segmented lesion volume and mean radioactivity concentration relative to the actual values were smaller than 15% and 25%, respectively. The effect of MR-based attenuation correction (three- and four-segment µ-maps) on bone lesion quantification was assessed using radioactive spheres filled with a K2HPO4 solution mimicking bone lesions. The four-segment µ-map resulted in an underestimation of the imaged radioactivity concentration of up to 15%, whereas the three-segment µ-map resulted in an overestimation of up to 10%. For twenty lesions identified in six patients, a comparison of 124I PET/MRI to PET/CT was performed with respect to segmented lesion volume and radioactivity concentration. The interclass correlation coefficients showed excellent agreement in segmented lesion volume and radioactivity concentration (0.999 and 0.95, respectively). In conclusion, it is feasible that accurate quantitative 124I PET/MRI could be used to perform radioiodine pre-therapy lesion dosimetry in DTC.

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

    International Nuclear Information System (INIS)

    Bäck, A

    2015-01-01

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

  10. In vivo thermoluminescent dosimetry in studies of helicoid computed tomography and excretory urogram; Dosimetria termoluminiscente In vivo en estudios de tomografia computada helicoidal y urograma excretor

    Energy Technology Data Exchange (ETDEWEB)

    Cruz C, D.; Azorin N, J. [UAM-I, 09340 Mexico D.F. (Mexico); Saucedo A, V.M.; Barajas O, J.L. [Unidad de Especialidades Medicas, Secretaria de la Defensa Nacional, 11500 Mexico D.F. (Mexico)

    2005-07-01

    The dosimetry is the field of measurement of the ionizing radiations. It final objective is to determine the 'absorbed dose' for people. The dosimetry is vital in the radiotherapy, the radiological protection and the treatment technologies by irradiation. Presently work, we develop 'In vivo' dosimetry, in exposed patients to studies of helical computed tomography and excretory urogram. The dosimetry 'in vivo' was carried out in 20 patients selected aleatorily, for each medical study. The absorbed dose was measured in points of interest located in crystalline, thyroid, chest and abdomen of each patient, by means of thermoluminescent dosemeters (TLD) LiF: Mg,Cu,P + Ptfe of national fabrication. Also it was quantified the dose in the working area. (Author)

  11. Preliminary evaluation of second harmonic direct detection scheme for low-dose range in alanine/EPR dosimetry

    International Nuclear Information System (INIS)

    Chen, Felipe; Graeff, Carlos F.O.; Baffa, Oswaldo

    2002-01-01

    The usefulness of a direct detection scheme of the second harmonic (2h) overmodulated signal from irradiated alanine in EPR dosimetry was studied. For this purpose, a group of DL-alanine/paraffin cylindrical pellets was produced. The dosimeters were irradiated with a 60 Co radiotherapy gamma source with doses of 0.05, 0.1, 0.5, 1 and 5 Gy. The EPR measurements were carried out in a VARIAN-E4 spectrometer operating in X-band with optimized parameters to obtain highest amplitude signals of both harmonics. The 2h signal was detected directly at twice the modulation frequency. In preliminary results, the 2h showed some advantages over the 1h such as better resolution for doses below 1 Gy, better repeatability results and better linear behaviour in the dose range indicated. (author)

  12. Evaluation of dose uncertainty in radiation processing using EPR spectroscopy and butylated hydroxytoluene rods as dosimetry system

    Science.gov (United States)

    Alkhorayef, M.; Mansour, A.; Sulieman, A.; Alnaaimi, M.; Alduaij, M.; Babikir, E.; Bradley, D. A.

    2017-12-01

    Butylatedhydroxytoluene (BHT) rods represent a potential dosimeter in radiation processing, with readout via electron paramagnetic resonance (EPR) spectroscopy. Among the possible sources of uncertainty are those associated with the performance of the dosimetric medium and the conditions under which measurements are made, including sampling and environmental conditions. Present study makes estimate of the uncertainties, investigating physical response in different resonance regions. BHT, a white crystalline solid with a melting point of between 70-73 °C, was investigated using 60Co gamma irradiation over the dose range 0.1-100 kGy. The intensity of the EPR signal increases linearly in the range 0.1-35 kGy, the uncertainty budget for high doses being 3.3% at the 2σ confidence level. The rod form represents an excellent alternative dosimeter for high level dosimetry, of small uncertainty compared to powder form.

  13. Reference dosimetry and small-field dosimetry in external beam radiotherapy: Results from a Danish intercomparison study

    DEFF Research Database (Denmark)

    Beierholm, Anders Ravnsborg; Behrens, Claus F.; Sibolt, Patrik

    -mators and the measured field sizes, although one clinic showed field dimensions that were down to 21 ± 3 % smaller than expected. Small-field correction factors were estimated for a PinPoint cham-ber and a diamond detector using a fibre-coupled organic scintilla-tor as reference, after correcting for volume averaging......) clinical applications of fiber-coupled plastic scintilla-tors. The study also demonstrated that the estimation of detector-specific correction factors in small fields is consistent among clinics and linac models, supporting the robustness and usefulness of the proposed IAEA formalism for detector...

  14. Neutron personnel dosimetry

    International Nuclear Information System (INIS)

    Griffith, R.V.

    1981-01-01

    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

  15. Dosimetry study of PHOTOFRIN-mediated photodynamic therapy in a mouse tumor model

    Science.gov (United States)

    Qiu, Haixia; Kim, Michele M.; Penjweini, Rozhin; Zhu, Timothy C.

    2016-03-01

    It is well known in photodynamic therapy (PDT) that there is a large variability between PDT light dose and therapeutic outcomes. An explicit dosimetry model using apparent reacted 1O2 concentration [1O2]rx has been developed as a PDT dosimetric quantity to improve the accuracy of the predicted ability of therapeutic efficacy. In this study, this explicit macroscopic singlet oxygen model was adopted to establish the correlation between calculated reacted [1O2]rx and the tumor growth using Photofrin-mediated PDT in a mouse tumor model. Mice with radiation-induced fibrosarcoma (RIF) tumors were injected with Photofrin at a dose of 5 mg/kg. PDT was performed 24h later with different fluence rates (50, 75 and 150 mW/cm2) and different fluences (50 and 135 J/cm2) using a collimated light applicator coupled to a 630nm laser. The tumor volume was monitored daily after PDT and correlated with the total light fluence and [1O2]rx. Photophysical parameters as well as the singlet oxygen threshold dose for this sensitizer and the RIF tumor model were determined previously. The result showed that tumor growth rate varied greatly with light fluence for different fluence rates while [1O2]rx had a good correlation with the PDT-induced tumor growth rate. This preliminary study indicated that [1O2]rx could serve as a better dosimetric predictor for predicting PDT outcome than PDT light dose.

  16. Determination of electrical characteristics of body tissues for computational dosimetry studies

    International Nuclear Information System (INIS)

    Silva, Rafael Monteiro da Cruz; Domingues, Luis Adriano M.C.; Neto, Athanasio Mpalantinos; Barbosa, Carlos Ruy Nunez

    2008-01-01

    Increasing public concern about human exposure to electromagnetic fields led to the development of International Exposure Standards, which reflect the actual scientific knowledge on this subject. Existing exposure limits (reference levels), are based on maximum admissible fields or induced currents densities inside human bodies, called basic restrictions. Since those physical quantities can not be readily measured, they must be estimated using techniques of computational dosimetry. These techniques rely on accurate computational modelling of human bodies to establish the relation of external field (electric / magnetic) to induced current (internal field). Nowadays the models available for human body simulation (FEM, FDM,...) are quite accurate, specially when using geometric discretization obtained from medical imaging techniques, however the determination of tissues characteristics (permittivity and conductivity) is still an issue to be dealt with. In current studies the electrical characteristics (permittivity and conductivity) of body tissues are based on values which were obtained from measurements done on tissue simples obtained from dead bodies. However those values may not represent adequately the behaviour of living tissues. In this paper a research designed to characterize the permittivity of human body tissues is presented, consisting of measurements and simulations designed to determine, using indirect methods, the electrical behaviour of living tissues. A study of exposure assessment on a real high voltage transmission line in Brazil, using measured permittivity values combined with a finite element model of the human body is presented in the panel. (author)

  17. Reproducibility study of thermoluminescent dosemeters for application in personal dosimetry; Estudo da reprodutibilidade de dosimetros termoluminescentes para a aplicacao em dosimetria pessoal

    Energy Technology Data Exchange (ETDEWEB)

    Medeiros, Beatriz M.; Morimoto, Richard; Menezes, Francisca L.; Ferri, Paulo L.S.; Santos, Osmar A. dos, E-mail: medeirosmbeatriz@gmail.com [Fundacao do Cancer, Rio de Janeiro, RJ (Brazil)

    2016-07-01

    Nowadays in radiotherapy services due to the big concern about the OEIs' safety is made the personal dosimetry of them. And Thermoluminescent Dosimetry is the most used dosimetric technique. It is necessary that the dosimeters are tested for their characterization and response evaluation before being used. One of these tests is the reproducibility test.This study aims to ensure that the dosimetric system analyzed has the same response to the same dose through the criteria presented by the Testing and Calibration Service Evaluation Committee - CASEC / IRD / CNEN contained in the IRD-RT Document Number 002.02 / 2010{sup o}. The groups showed a coefficient of variation equal to 3.6% for irradiated dosimeters with 25 cGy, 2.7% for irradiated dosimeters with 40 cGy, 6.6% for irradiated dosimeters with 50 cGy and 4.1% for dosimeters irradiated with 100 cGy. Since all these values are less than 7.5%, all four dosimeters groups would be accepted by the criteria used. (author)

  18. Argentine intercomparison programme for personal dosimetry

    International Nuclear Information System (INIS)

    Gregori, B.N.; Papadopulos, S.B.; Cruzate, J.; Kunst, J.J.; Saravi, M.

    2005-01-01

    Full text: In 1997 began in Argentine, sponsored by Nuclear Regulatory Authority (ARN) the intercomparison program for personal dosimetry laboratories, on a voluntary basis. Up to know 6 exercises have been done. The program began with a workshop to present the quantities, personal dose equivalent, Hp(10) and extremities dose equivalent, Hs(d). The first aim of this program was to know the true sate of personal dosimetry laboratories in the country, and then introduce the personal dose equivalent, Hp(10) into the dose measurements. The Regional Reference Center for Dosimetry (CCR), belonging to CNEA and the Physical Dosimetry Laboratory of ARN performed the irradiation. Those were done air free and on ICRU phantom, using x-ray, quality ISO: W60, W110 and W200; and 137 Cs and 60 Co gamma rays. The irradiation was made following ISO 4037 (2) recommendations. There are studied the dose, energy and angular response of the different measuring system. The range of the dose analyzed was from 0.2 mSv up to 80 mSv. The beam incidence was normal and also 20 o and 60 o . The dosimeters irradiation's were performed kerma in free in air and in phantom in order to study the availability of the service to evaluate the behavior as a function of kerma free in air or Hp(10). At the same time several items have been asked to each participant referring to the action range, the detectors characteristics, the laboratory procedures, the existence of an algorithm and its use for the dosimeter evaluation and the wish to participate in a quality assurance program. The program worked in writing a standard of personal dosimetry laboratories, that was published in 2001. In this work the results of each laboratory and its performance based on the ICRP-60 and ICRP-35 acceptance criteria are shown. Also the laboratory evolution and inquiry analyses have been included. (author)

  19. [Study on therapeutic dosimetry and biologic effect of high intensity focused ultrasound].

    Science.gov (United States)

    He, Xuemei; Xiong, Xin; Zou, Jianzhong; Li, Faqi; Ma, Ping; Wang, Zhibiao

    2009-02-01

    This study was aimed at exploring the high intensity focused ultrasound(HIFU) therapeutic dosimetry and its biologic effect. In-vitro, bovine liver was immersed into 0.9% NS and degassed for application. The JC Model-focused ultrasound tumor therapeutic system was used in the experiment. The HIFU parameters were: frequency 1.6 MHz, depth 20 mm, acoustic power from 16.44 W to 196.32 W. Under each power, at radiating times from is to 20 s, bioptic specimens were obtained from all samples. The results showed when the acoustic power was equal to or higher than 179.96 W, only is of radiating is adequate to induce coagulative necrosis, and when the acoustic power was lower than 65.44 W, the radiating time to produce coagulative necrosis was about 7 s. In the range of 65.44-179.96 W, at each time when the acoustic power was set up with an increment of 16.36 W, the time to produce coagulative necrosis was 1-2 s shorter. The form of biological focal region (BFR) varied with the acoustic power and HIFU irradiation time. The size of BFR increased with the increase of HIFU irradiation dosage (acoustic power x exposure time). There is positive correlation between the size of BFR and the dosage of HIFU irradiation (y = 0.0164x(1.05591), R5 = 0.9238, P < 0.05).

  20. ESR dosimetry study for the residents of Kazakhstan exposed to radioactive fallout on 24, August 1956

    International Nuclear Information System (INIS)

    Zhumadilov, K.; Ivannikov, A.; Zharlyganova, D.; Zhumadilov, Zh.; Stepanenko, V.; Abralina, Sh.; Sadvokasova, L.; Zhumadilova, A.; Toyoda, S.; Endo, S.; Okamoto, T.; Hoshi, M.

    2011-01-01

    The method of electron spin resonance (ESR) dosimetry has been applied to human tooth enamel in order to obtain individual absorbed doses from the population of settlements within the vicinity of the central axis of the radioactive fallout trace from the contaminating nuclear surface test of 24, August 1956. Most of the settlements (Glubokoe, Tavriya, and Gagarino) are located near Ust-Kamenogorsk city, in Kazakhstan (about 400 km to the east from the epicenter of the explosion at the Semipalatinsk Nuclear Test Site (SNTS)). It was found that the excess doses obtained after the subtraction of natural background radiation ranged up to about 120 mGy for the residents of Ust-Kamenogorsk city, whose tooth enamel was formed before 1956. For the residents of Gagarino, excess doses do not exceed 47 mGy for all ages. For the residents of Tavriya, the maximum of excess dose was determined as 54 mGy and for the residents of Glubokoe, the maximum excess dose was about 83 mGy. For the population of the Shemonaikha settlements (about 70 km from the centerline of the radioactive fallout trace) the highest excess dose is 110 mGy. Also for this study, Znamenka village (about 130 km from the epicenter) was included. The Kokpekty settlement was chosen as a control and not subjected to any radioactive contamination and is located 400 km to the Southeast from SNTS.

  1. ESR dosimetry study of population in the vicinity of the Semipalatinsk Nuclear Test Site

    International Nuclear Information System (INIS)

    Zhumadilov, Kassym; Ivannikov, Alexander; Stepanenko, Valeriy; Zharlyganova, Dinara; Toyoda, Shin; Zhumadilov, Zhaxybay; Hoshi, Masaharu

    2013-01-01

    A tooth enamel electron spin resonance (ESR) dosimetry study was carried out with the purpose of obtaining the individual absorbed radiation doses of population from settlements in the Semipalatinsk region of Kazakhstan, which was exposed to radioactive fallout traces from nuclear explosions in the Semipalatinsk Nuclear Test Site and Lop Nor test base, China. Most of the settlements are located near the central axis of radioactive fallout trace from the most contaminating surface nuclear test, which was conducted on 29 August 1949, with the maximum detected excess dose being 430 ± 93 mGy. A maximum dose of 268 ± 79 mGy was determined from the settlements located close to radioactive fallout trace resulting from surface nuclear tests on 24 August 1956 (Ust-Kamenogorsk, Znamenka, Shemonaikha, Glubokoe, Tavriya and Gagarino). An accidental dose of 56 ± 42 mGy was found in Kurchatov city residents located close to fallout trace after the nuclear test on 7 August 1962. This method was applied to human tooth enamel to obtain individual absorbed doses of residents of the Makanchi, Urdzhar and Taskesken settlements located near the Kazakhstan-Chinese border due to the influence of nuclear tests (1964-1981) at Lop Nor. The highest dose was 123 ± 32 mGy. (author)

  2. CaSO4:Dy and/or Tm: study of its properties for dosimetry application

    International Nuclear Information System (INIS)

    Ferreira, M.M.

    1979-01-01

    In order obtain in practical and cheap solid state dosimeter with high sensitivity, a technique initially developed to cold press a mixture of suitable materials in their powder form sensitive to radiation. The material initially used was natural CaF 2 (fluorite) for this salt was extensively studied in radiation dosimetry since it shows a thermoluminescent (TL) effect after radiation. However, natural calcium fluorite shows two main disadvantages: its high senstivity to room light and the impossibility to control its impurity content due to its natural origin. Calcium sulphate was thus used as a good substitute of fluorite. Rare earths doped calcium sulphate shows a high TL sensitivity and is not disturbed by light. It is also easily obtained in the laboratory under controlled conditions so to get reproducible impurity content. The best dosimeters that can be produced with rare earth doped calcium sulphate are CaSO 4 :Dy and CaSO 4 :Tm. Calcium sulphate, simultaneously doped with Tm and Dy was produced and 100% increase was obtained in the TL sensitivity when compared with the individually are earth doped calcium sulphate. (Author) [pt

  3. Evaluation of the external radiation exposure dosimetry and calculation of maximum permissible concentration values for airborne materials containing 18F, 15O, 13N, 11C and 133Xe

    International Nuclear Information System (INIS)

    Piltingsrud, H.V.; Gels, G.L.

    1985-01-01

    To better understand the dose equivalent (D.E.) rates produced by airborne releases of gaseous positron-emitting radionuclides under various conditions of cloud size, a study of the external radiation exposure dosimetry of these radionuclides, as well as negatron, gamma and x-ray emitting 133Xe, was undertaken. This included a calculation of the contributions to D.E. as a function of cloud radii, at tissue depths of 0.07 mm (skin), 3 mm (lens of eye) and 10 mm (whole body) from both the particulate and photon radiations emitted by these radionuclides. Estimates of maximum permissible concentration (MPC) values were also calculated based on the calculated D.E. rates and current regulations for personnel radiation protection (CFR84). Three continuous air monitors, designed for use with 133Xe, were evaluated for applications in monitoring air concentrations of the selected positron emitters. The results indicate that for a given radionuclide and for a cloud greater than a certain radius, personnel radiation dosimeters must respond acceptably to only the photon radiations emitted by the radionuclide to provide acceptable personnel dosimetry. For clouds under that radius, personnel radiation dosimeters must also respond acceptably to the positron or negatron radiations to provide acceptable personnel dosimetry. It was found that two out of the three air concentration monitors may be useful for monitoring air concentrations of the selected positron emitters

  4. Radiation dosimetry in radiotherapy with internal emitters

    International Nuclear Information System (INIS)

    Stabin, Michael G.

    1997-01-01

    Full text. Radiation dosimetry radionuclides are currently being labeled to various biological agents used in internal emitter radiotherapy. This talk will review the various technologies and types of radiolabel in current use, with focus on the characterization of the radiation dose to the various important tissues of the body. Methods for obtaining data, developing kinetic models, and calculating radiation doses will be reviewed. Monoclonal antibodies are currently being labeled with both alpha and beta emitting radionuclides in attempts to find effective agents against cancer. Several radionuclides are also being used as bone pain palliation agents. These agents must be studied in clinical trials to determine the biokinetics and radiation dosimetry prior to approval for general use. In such studies, it is important to ensure the collection of the appropriate kinds of data and to collect the data at appropriate time intervals. The uptake and retention of activity in all significant source organs and in excreta be measured periodically (with at least 2 data points phase of uptake or clearance). Then, correct dosimetry methods must be applied - the best available methods for characterizing the radionuclide kinetic and for estimating the dosimetry in the various organs of the body especially the marrow, should be used. Attempts are also under way to develop methods for estimating true patient-specific dosimetry. Cellular and animal studies are also. Valuable in evaluating the efficacy of the agents in shrinking or eliminating tumors; some results from such studies will also be discussed. The estimation of radiation doses to patients in therapy with internal emitters involves several complex phases of analysis. Careful attention to detail and the use of the best available methods are essential to the protection of the patient and a successful outcome

  5. Internal dosimetry technical basis manual

    Energy Technology Data Exchange (ETDEWEB)

    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.

  6. Internal dosimetry technical basis manual

    International Nuclear Information System (INIS)

    1990-01-01

    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

  7. Internal radiation dosimetry in radionuclide therapy

    International Nuclear Information System (INIS)

    Kim, Kyeong Min; Lim, Sang Moo

    2006-01-01

    Radionuclide therapy has been continued for treatment of incurable diseases for past decades. Relevant evaluation of absorbed dose in radionuclide therapy in important to predict treatment output and essential for making treatment planning to prevent unexpected radiation toxicity. Many scientists in the field related with nuclear medicine have made effort to evolve concept and technique for internal radiation dosimetry. In this review, basic concept of internal radiation dosimetry if described and recent progress in method for dosimetry is introduced

  8. Thermoluminescent dosimetry in pediatric patients subjected to TAC cranium multi cutting studies

    International Nuclear Information System (INIS)

    Tabares V, M.J.; Azorin N, J.; Azorin V, J.C.

    2007-01-01

    Full text: In this work the doses to critical organs in pediatric patient subjected to studies of multi cutting skull tomography were determined. The study included patient smaller than 16. The used tomograph was a Siemens Somaton 16 plus multi cutting. The dosimetry one carries out with thermoluminescent dosemeters of LiF:Mg,Cu,P +Ptfe of national production. This dosemeters type was used due to it characteristics, such as low fading, equivalence with the tissue, easy handling and reading and independence of it answer with the radiation energy. The value of the absorbed doses in organs in the simple study results half of the obtained value in the contrasted study that which indicates that the CTDI vol is proportional to the dose to organ. In the case of the skull three-dimensional reconstruction tomography the CTDI vol was practically the same one that for simple tomography was practically; however, the doses to organs differed significantly. When comparing the TDI vol value of the three-dimensional reconstruction tomography with that of the contrasted tomography the obtained reason it was 1:2; however, the doses to organ didn't show the same relationship and the absorbed dose in the case of the thyroid gland was even bigger in the study of three-dimensional reconstruction. The value of the CTDI vol is a good indicator of the exposure factors selected for the tomographic exploration and it is useful for the determination of the effective dose, but it doesn't indicate the absorbed dose to organ. (Author)

  9. Studies on 192Ir afterloading irradiation of the canine prostate with special consideration of thermoluminescent dosimetry

    International Nuclear Information System (INIS)

    Reuter, M.

    1986-01-01

    A method for high dose rate afterloading irradiation of the prostate with iridium 192 was developed. The isodoses of the urethra and rectum, which were measured by means of thermoluminescent dosimetry, showed deviations from the doses pre-calculated by computer (BRACHY), because this calculation is based on an anatomically ideal condition. (MBC) [de

  10. Using soils for accident dosimetry: a preliminary study using optically stimulated luminescence from quartz

    DEFF Research Database (Denmark)

    Fujita, Hiroki; Jain, Mayank; Murray, Andrew S.

    2011-01-01

    . The objective was to assess the potential of SAROSL dosimetry using soils for retrospective assessment of a radiation accident. Variation in dose with depth was also measured. The SAR data showed good reproducibility and dose recovery, and there was no evidence of fading of the quartz signal based on “delayed...

  11. Fast neutron spectrometry and dosimetry

    International Nuclear Information System (INIS)

    Blaize, S.; Ailloud, J.; Mariani, J.; Millot, J.P.

    1958-01-01

    We have studied fast neutron spectrometry and dosimetry through the recoil protons they produce in hydrogenated samples. In spectrometric, we used nuclear emulsions, in dosimetric, we used polyethylene coated with zinc sulphide and placed before a photomultiplier. (author) [fr

  12. Development and evaluation of a phantom for multi-purpose dosimetry in intensity-modulated radiation therapy

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Hae Sun; Kim, Chan Hyeong [Hanyang University, Seoul (Korea, Republic of); Park, Joo Hwan [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Han, Young Yih [Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of); Kum, O Yeon [Yonsei University College of Medicine, Seoul (Korea, Republic of)

    2011-08-15

    A LEGO-type multi-purpose dosimetry phantom was developed for intensity-modulated radiation therapy (IMRT), which requires various types of challenging dosimetry. Polystyrene, polyethylene, polytetrafluoroethylene (PTFE), and polyurethane foam (PU-F) were selected to represent muscle, fat, bone, and lung tissue, respectively, after considering the relevant mass densities, elemental compositions, effective atomic numbers, and photon interaction coefficients. The phantom, which is composed of numerous small pieces that are similar to LEGO blocks, provides dose and dose distribution measurements in homogeneous and heterogeneous media. The phantom includes dosimeter holders for several types of dosimeters that are frequently used in IMRT dosimetry. An ion chamber and a diode detector were used to test dosimetry in heterogeneous media under radiation fields of various sizes. The data that were measured using these dosimeters were in disagreement when the field sizes were smaller than 1.5 x 1.5 cm{sup 2} for polystyrene and PTFE, or smaller than 3 x 3 cm{sup 2} for an air cavity. The discrepancy was as large as 41% for the air cavity when the field size was 0.7 x 0.7 cm{sup 2}, highlighting one of the challenges of IMRT small field dosimetry. The LEGO-type phantom is also very useful for two-dimensional dosimetry analysis, which elucidates the electronic dis-equilibrium phenomena on or near the heterogeneity boundaries

  13. A Monte Carlo study of macroscopic and microscopic dose descriptors for kilovoltage cellular dosimetry

    Science.gov (United States)

    Oliver, P. A. K.; Thomson, Rowan M.

    2017-02-01

    This work investigates how doses to cellular targets depend on cell morphology, as well as relations between cellular doses and doses to bulk tissues and water. Multicellular models of five healthy and cancerous soft tissues are developed based on typical values of cell compartment sizes, elemental compositions and number densities found in the literature. Cells are modelled as two concentric spheres with nucleus and cytoplasm compartments. Monte Carlo simulations are used to calculate the absorbed dose to the nucleus and cytoplasm for incident photon energies of 20-370 keV, relevant for brachytherapy, diagnostic radiology, and out-of-field radiation in higher-energy external beam radiotherapy. Simulations involving cell clusters, single cells and single nuclear cavities are carried out for cell radii between 5 and 10~μ m, and nuclear radii between 2 and 9~μ m. Seven nucleus and cytoplasm elemental compositions representative of animal cells are considered. The presence of a cytoplasm, extracellular matrix and surrounding cells can affect the nuclear dose by up to 13 % . Differences in cell and nucleus size can affect dose to the nucleus (cytoplasm) of the central cell in a cluster of 13 cells by up to 13 % (8 % ). Furthermore, the results of this study demonstrate that neither water nor bulk tissue are reliable substitutes for subcellular targets for incident photon energies  <50 keV: nuclear (cytoplasm) doses differ from dose-to-medium by up to 32 % (18 % ), and from dose-to-water by up to 21 % (8 % ). The largest differences between dose descriptors are seen for the lowest incident photon energies; differences are less than 3 % for energies ≥slant 90 keV. The sensitivity of results with regard to the parameters of the microscopic tissue structure model and cell model geometry, and the importance of the nucleus and cytoplasm as targets for radiation-induced cell death emphasize the importance of accurate models for cellular dosimetry studies.

  14. Techniques for radiation measurements: Micro-dosimetry and dosimetry

    International Nuclear Information System (INIS)

    Waker, A. J.

    2006-01-01

    Experimental Micro-dosimetry is concerned with the determination of radiation quality and how this can be specified in terms of the distribution of energy deposition arising from the interaction of a radiation field with a particular target site. This paper discusses various techniques that have been developed to measure radiation energy deposition over the three orders of magnitude of site-size; nano-meter, micrometer and millimetre, which radiation biology suggests is required to fully account for radiation quality. Inevitably, much of the discussion will concern the use of tissue-equivalent proportional counters and variants of this device, but other technologies that have been studied, or are under development, for their potential in experimental Micro-dosimetry are also covered. Through an examination of some of the quantities used in radiation metrology and dosimetry the natural link with Micro-dosimetric techniques will be shown and the particular benefits of using Micro-dosimetric methods for dosimetry illustrated. (authors)

  15. Study of dosimetry errors in the framework of a concerted international study about the risk of cancer in nuclear industry workers. Study of the errors made on dose estimations of 100 to 3000 keV photons

    International Nuclear Information System (INIS)

    Thierry Chef, I.

    2000-01-01

    Ionizing radiations are uncontested factors of cancer risk and the radioprotection standards are defined on the basis of epidemiological studies of persons exposed to high doses of radiations (atomic bombs and therapeutic medical exposures). An epidemiological study of cancer risk has been carried out on nuclear industry workers from 17 countries in order to check these standards and to directly evaluate the risk linked with long duration exposures to low doses. The techniques used to measure the workers' doses have changed with time and these evolutions have been different in the different countries considered. The study of dosimetry errors aims at estimating the compatibility of the doses with respect to the periods of time and to the countries, and at quantifying the errors that could have disturbed the dose measurements during the first years and their consideration in the risk estimation. A compilation of the information available about dosimetry in the participating countries has been performed and the main sources of errors have been identified. Experiments have been carried out to test the response of the dosimeters used and to evaluate the conditions of exposure inside the companies. The biases and uncertainties have been estimated per company and per period of time and the most important correspond to the oldest measurements performed. This study contributes also to improve the knowledge of the working conditions and of the preciseness of dose estimations. (J.S.)

  16. Dosimetry on the radiological risks prevention in radiotherapy; La dosimetria en la prevencion de riesgos radiologicos en radioterapia

    Energy Technology Data Exchange (ETDEWEB)

    Fornet R, O. M.; Perez G, F., E-mail: nuclear2@citmahlg.holguin.inf.cu [Delegacion Territorial del CITMA, Peralta 16 esq. P. Feria, Rpto. Peralta, 80400 Holguin (Cuba)

    2014-08-15

    Dosimetry in its various forms plays a determining role on the radiological risks prevention in radiotherapy. To prove this in this paper is shown an analysis based on the risk matrix method, how the dosimetry can influence in each stages of a radiotherapy service; installation and acceptance, operation, maintenance and calibration. For each one of these stages the role that can play is analyzed as either the initiating event of a radiological accident or limiting barrier of these events of the dosimetric processes used for the individual dosimetry, the area monitoring, fixed or portable, for radiation beam dosimetry and of the patients for a radiotherapy service with cobalt-therapy equipment. The result of the study shows that the application of a prospective approach in the role evaluation of dosimetry in the prevention and mitigation of the consequences of a radiological accident in radiotherapy is crucial and should be subject to permanent evaluation at each development stage of these services. (author)

  17. SU-F-T-17: A Feasibility Study for the Transit Dosimetry with a Glass Dosimeter in Brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Moon, S; Yoon, M [Korea University, Seoul (Korea, Republic of); Chung, W; Chung, M; Kim, D [Kyung Hee University Hospital at Gangdong, Gangdonggu, Seoul (Korea, Republic of)

    2016-06-15

    Purpose: Confirming the dose delivered to a patient is important to make sure the treatment quality and safety of the radiotherapy. Measuring a transit dose of the patient during the radiotherapy could be an interesting way to confirm the patient dose. In this study, we evaluated the feasibility of the transit dosimetry with a glass dosimeter in brachytherapy. Methods: We made a phantom that inserted the glass dosimeters and placed under patient lying on a couch for cervix cancer brachytherapy. The 18 glass dosimeters were placed in the phantom arranged 6 per row. A point putting 1cm vertically from the source was prescribed as 500.00 cGy. Solid phantoms of 0, 2, 4, 6, 8, 10 cm were placed between the source and the glass dosimeter. The transit dose was measured each thickness using the glass dosimeters and compared with a treatment planning system (TPS). Results: When the transit dose was smaller than 10 cGy, the average of the differences between measured values and calculated values by TPS was 0.50 cGy and the standard deviation was 0.69 cGy. If the transit dose was smaller than 100 cGy, the average of the error was 1.67 ± 4.01 cGy. The error to a point near the prescription point was −14.02 cGy per 500.00 cGy of the prescription dose. Conclusion: The distances from the sources to skin of the patient generally are within 10 cm for cervix cancer cases in brachytherapy. The results of this preliminary study showed the probability of the glass dosimeter as the transit dosimeter in brachytherapy.

  18. Topics in radiation dosimetry radiation dosimetry

    CERN Document Server

    1972-01-01

    Radiation Dosimetry, Supplement 1: Topics in Radiation Dosimetry covers instruments and techniques in dealing with special dosimetry problems. The book discusses thermoluminescence dosimetry in archeological dating; dosimetric applications of track etching; vacuum chambers of radiation measurement. The text also describes wall-less detectors in microdosimetry; dosimetry of low-energy X-rays; and the theory and general applicability of the gamma-ray theory of track effects to various systems. Dose equivalent determinations in neutron fields by means of moderator techniques; as well as developm

  19. Proton dosimetry intercomparison

    International Nuclear Information System (INIS)

    Vatnitsky, S.; Siebers, J.; Miller, D.; Moyers, M.; Schaefer, M.; Jones, D.; Vynckier, S.; Hayakawa, Y.; Delacroix, S.; Isacsson, U.; Medin, J.; Kacperek, A.; Lomax, A.; Coray, A.; Kluge, H.; Heese, J.; Verhey, L.; Daftari, I.; Gall, K.; Lam, G.; Beck, T.; Hartmann, G.

    1996-01-01

    Background and purpose: Methods for determining absorbed dose in clinical proton beams are based on dosimetry protocols provided by the AAPM and the ECHED. Both groups recommend the use of air-filled ionization chambers calibrated in terms of exposure or air kerma in a 60 Co beam when a calorimeter or Faraday cup dosimeter is not available. The set of input data used in the AAPM and the ECHED protocols, especially proton stopping powers and w-value is different. In order to verify inter-institutional uniformity of proton beam calibration, the AAPM and the ECHED recommend periodic dosimetry intercomparisons. In this paper we report the results of an international proton dosimetry intercomparison which was held at Loma Linda University Medical Center. The goal of the intercomparison was two-fold: first, to estimate the consistency of absorbed dose delivered to patients among the participating facilities, and second, to evaluate the differences in absorbed dose determination due to differences in 60 Co-based ionization chamber calibration protocols. Materials and methods: Thirteen institutions participated in an international proton dosimetry intercomparison. The measurements were performed in a 15-cm square field at a depth of 10 cm in both an unmodulated beam (nominal accelerator energy of 250 MeV) and a 6-cm modulated beam (nominal accelerator energy of 155 MeV), and also in a circular field of diameter 2.6 cm at a depth of 1.14 cm in a beam with 2.4 cm modulation (nominal accelerator energy of 100 MeV). Results: The results of the intercomparison have shown that using ionization chambers with 60 Co calibration factors traceable to standard laboratories, and institution-specific conversion factors and dose protocols, the absorbed dose specified to the patient would fall within 3% of the mean value. A single measurement using an ionization chamber with a proton chamber factor determined with a Faraday cup calibration differed from the mean by 8%. Conclusion: The

  20. Internal Dosimetry and the pharmacokinetic of the Cuban Kit of Methoxy-Isobutyl-Isonitrile (MIBI) marked with 99mTc

    International Nuclear Information System (INIS)

    Torres, L.A.; Pereztol, O.; Rodriguez, J.L.; Alvarez, I.; Fraxedas, R.; Mesa, G.; Rodriguez, R.

    1998-01-01

    The objective of the present work consisted on evaluating the Internal Dosimetry and the pharmacokinetic of the Cuban Kit of Methoxy-Isobutyl-Isonitrile (MIBI) marked with 99mTc. In the dosimetry studies and biodistribution five healthy volunteers were included and in the pharmacokinetic studies five patients were included with less than 5% of probability of suffering illness of artery coronary

  1. Evaluation of the UF/NCI hybrid computational phantoms for use in organ dosimetry of pediatric patients undergoing fluoroscopically guided cardiac procedures.

    Science.gov (United States)

    Marshall, Emily L; Borrego, David; Tran, Trung; Fudge, James C; Bolch, Wesley E

    2018-03-01

    Epidemiologic data demonstrate that pediatric patients face a higher relative risk of radiation induced cancers than their adult counterparts at equivalent exposures. Infants and children with congenital heart defects are a critical patient population exposed to ionizing radiation during life-saving procedures. These patients will likely incur numerous procedures throughout their lifespan, each time increasing their cumulative radiation absorbed dose. As continued improvements in long-term prognosis of congenital heart defect patients is achieved, a better understanding of organ radiation dose following treatment becomes increasingly vital. Dosimetry of these patients can be accomplished using Monte Carlo radiation transport simulations, coupled with modern anatomical patient models. The aim of this study was to evaluate the performance of the University of Florida/National Cancer Institute (UF/NCI) pediatric hybrid computational phantom library for organ dose assessment of patients that have undergone fluoroscopically guided cardiac catheterizations. In this study, two types of simulations were modeled. A dose assessment was performed on 29 patient-specific voxel phantoms (taken as representing the patient's true anatomy), height/weight-matched hybrid library phantoms, and age-matched reference phantoms. Two exposure studies were conducted for each phantom type. First, a parametric study was constructed by the attending pediatric interventional cardiologist at the University of Florida to model the range of parameters seen clinically. Second, four clinical cardiac procedures were simulated based upon internal logfiles captured by a Toshiba Infinix-i Cardiac Bi-Plane fluoroscopic unit. Performance of the phantom library was quantified by computing both the percent difference in individual organ doses, as well as the organ dose root mean square values for overall phantom assessment between the matched phantoms (UF/NCI library or reference) and the patient

  2. Long term nuclear data needs for internal radiation dosimetry

    International Nuclear Information System (INIS)

    Burrows, T.W.

    2001-01-01

    The Evaluated Nuclear Structure Data File (ENSDF) is the principle source of nuclear data for internal radiation dosimetry and is, therefore, described briefly. Nuclear data needs and accuracy requirements for internal radiation dosimetry are summarized. Currently available sources of internal radiation dosimetry data are outlined and the need for traceability and documentation of these data is discussed. (author)

  3. Dosimetry study of [I-131] and [I-125]- meta-iodobenz guanidine in a simulating model for neuroblastoma metastasis.

    Science.gov (United States)

    Roa, W H; Yaremko, B; McEwan, A; Amanie, J; Yee, D; Cho, J; McQuarrie, S; Riauka, T; Sloboda, R; Wiebe, L; Loebenberg, R; Janicki, C

    2013-02-01

    The physical properties of I-131 may be suboptimal for the delivery of therapeutic radiation to bone marrow metastases, which are common in the natural history of neuroblastoma. In vitro and preliminary clinical studies have implied improved efficacy of I-125 relative to I-131 in certain clinical situations, although areas of uncertainty remain regarding intratumoral dosimetry. This prompted our study using human neuroblastoma multicellular spheroids as a model of metastasis. 3D dose calculations were made using voxel-based Medical Internal Radiation Dosimetry (MIRD) and dose-point-kernel (DPK) techniques. Dose distributions for I-131 and I-125 labeled mIBG were calculated for spheroids (metastases) of various sizes from 0.01 cm to 3 cm diameter, and the relative dose delivered to the tumors was compared for the same limiting dose to the bone marrow. Based on the same data, arguments were advanced based upon the principles of tumor control probability (TCP) to emphasize the potential theoretical utility of I-125 over I-131 in specific clinical situations. I-125-mIBG can deliver a higher and more uniform dose to tumors compared to I-131 mIBG without increasing the dose to the bone marrow. Depending on the tumor size and biological half-life, the relative dose to tumors of less than 1 mm diameter can increase several-fold. TCP calculations indicate that tumor control increases with increasing administered activity, and that I-125 is more effective than I-131 for tumor diameters of 0.01 cm or less. This study suggests that I-125-mIBG is dosimetrically superior to I-131-mIBG therapy for small bone marrow metastases from neuroblastoma. It is logical to consider adding I-125-mIBG to I-131-mIBG in multi-modality therapy as these two isotopes could be complementary in terms of their cumulative dosimetry.

  4. Neutron beam measurement dosimetry

    International Nuclear Information System (INIS)

    Amaro, C.R.

    1995-01-01

    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

  5. Radiotherapy gel dosimetry: a review

    International Nuclear Information System (INIS)

    Baldock, C.

    2003-01-01

    Radiation therapy or radiotherapy is a common form of cancer treatment. Recent advances in radiotherapy such as intensity modulated radiation therapy indicate that treatment outcomes may be improved. The principle limitation of these more advanced techniques of radiation therapy is the ability to quantify the absorbed radiation dose to the tumour which is related to the 3- dimensional geometry of the tumour. The main advances in 3-dimensional radiation dosimetry are the development of radiation sensitive polymer gel dosimeters. The use of radiation sensitive gels for radiation dosimetry in cancer therapy was first suggested in the 1950s. It was subsequently shown in 1984 that radiation induced changes in nuclear magnetic resonance relaxation properties of gels infused with conventional Fricke dosimetry solutions could be measured. Due to diffusion-related limitations in the use of Fricke gels, alternative polymer gel dosimeters were subsequently suggested in 1992. Since then, both magnetic resonance and optical imaging techniques have been used to evaluate polymer gel dosimeters to produce three-dimensional radiation dose distributions. More recently the uses of x-ray computer tomography and vibrational spectroscopy have also been demonstrated as valuable techniques in the evaluation of these dosimetry gels. Although not yet used routinely clinically, applications of these radiologically soft-tissue equivalent gel dosimeters have been shown to have great potential in the evaluation of complex radiation dose distributions. A review of 3-dimensional radiotherapy gel dosimetry is presented

  6. Evaluation of 3D printing materials for fabrication of a novel multi-functional 3D thyroid phantom for medical dosimetry and image quality

    International Nuclear Information System (INIS)

    Alssabbagh, Moayyad; Tajuddin, Abd Aziz; Abdulmanap, Mahayuddin; Zainon, Rafidah

    2017-01-01

    Recently, the three-dimensional printer has started to be utilized strongly in medical industries. In the human body, many parts or organs can be printed from 3D images to meet accurate organ geometries. In this study, five common 3D printing materials were evaluated in terms of their elementary composition and the mass attenuation coefficients. The online version of XCOM photon cross-section database was used to obtain the attenuation values of each material. The results were compared with the attenuation values of the thyroid listed in the International Commission on Radiation Units and Measurements - ICRU 44. Two original thyroid models (hollow-inside and solid-inside) were designed from scratch to be used in nuclear medicine, diagnostic radiology and radiotherapy for dosimetry and image quality purposes. Both designs have three holes for installation of radiation dosimeters. The hollow-inside model has more two holes in the top for injection the radioactive materials. The attenuation properties of the Polylactic Acid (PLA) material showed a very good match with the thyroid tissue, which it was selected to 3D print the phantom using open source RepRap, Prusa i3 3D printer. The scintigraphy images show that the phantom simulates a real healthy thyroid gland and thus it can be used for image quality purposes. The measured CT numbers of the PA material after the 3D printing show a close match with the human thyroid CT numbers. Furthermore, the phantom shows a good accommodation of the TLD dosimeters inside the holes. The 3D fabricated thyroid phantom simulates the real shape of the human thyroid gland with a changeable geometrical shape-size feature to fit different age groups. By using 3D printing technology, the time required to fabricate the 3D phantom was considerably shortened compared to the longer conventional methods, where it took only 30 min to print out the model. The 3D printing material used in this study is commercially available and cost

  7. First Evaluation of PET-Based Human Biodistribution and Dosimetry of 18F-FAZA, a Tracer for Imaging Tumor Hypoxia.

    Science.gov (United States)

    Savi, Annarita; Incerti, Elena; Fallanca, Federico; Bettinardi, Valentino; Rossetti, Francesca; Monterisi, Cristina; Compierchio, Antonia; Negri, Giampiero; Zannini, Piero; Gianolli, Luigi; Picchio, Maria

    2017-08-01

    18 F-labeled fluoroazomycinarabinoside ( 18 F-FAZA) is a PET biomarker for noninvasive identification of regional tumor hypoxia. The aim of the present phase I study was to evaluate the biodistribution and dosimetry of 18 F-FAZA in non-small cell lung cancer patients. Methods: Five patients awaiting surgical resection of histologically proven or radiologically suspected non-small cell lung cancer were prospectively enrolled in the study. The patients underwent PET/CT after injection of 371 ± 32 MBq of 18 F-FAZA. The protocol consisted of a 10-min dynamic acquisition of the heart to calculate the activity in blood, followed by 4 whole-body PET/CT scans, from the vertex to the mid thigh, at 10, 60, 120, and 240 min after injection. Urine samples were collected after each imaging session and at 360 min after injection. Volumes of interest were drawn around visually identifiable source organs to generate time-activity curves. Residence times were determined from time-activity curves, and effective doses to individual organs and the whole body were calculated using OLINDA/EXM 1.2 for the standard male and female phantoms. Results: Blood clearance was characterized by a rapid distribution followed by first-order elimination. The highest uptake was in muscle and liver, with respective percentage injected activity (%IA) peaks of 42.7 ± 5.3 %IA and 5.5 ± 0.6 %IA. The total urinary excretion was 15 %IA. The critical organ, with the highest absorbed radiation doses, was the urinary bladder wall, at 0.047 ± 0.008 and 0.067 ± 0.007 mGy/MBq for the 2- and 4-h voiding intervals, respectively. The effective doses for the standard male and female phantoms were 0.013 ± 0.004 and 0.014 ± 0.004 mSv/MBq, respectively, depending on the voiding schedule. Conclusion: With respect to the available literature, the biodistribution of 18 F-FAZA in humans appeared to be slightly different from that in mice, with a low clearance in humans. Therefore, use of animal data may moderately

  8. Study of radiation-induced paramagnetic centers in quartz and its possible use in radiation dosimetry

    International Nuclear Information System (INIS)

    Mansour, A.M.E.

    2008-01-01

    A new EPR dosimetry system has been developed based on the radiation-formed stable paramagnetic centers in quartz. The first part of the thesis includes the preparation of quartz rods (diameter = 3 mm, length = 10 mm) where quartz powder was mixed with molten mixture of paraffin wax and ethylene vinyl acetate copolymer (EVA). The binding-mixture EVA / paraffin do not present interference or noise in the EPR signal before or after irradiation to high doses. The quartz rods were prepared by different concentrations (5, 10, 20, 30 and 50 %). The rods (30 %) show good mechanical properties for safe and multi-use handling. The second part is concerned with studying the dosimetric characteristics of gamma irradiation sensitive rods where the radiation-formed stable free radicals (E-center, peroxy radical and non-bridging oxygen hole center) which analyzed by using electron paramagnetic resonance (EPR) spectrometer. Unirradiated rods have no EPR signals. The useful dose range of these rods was found to range from 0.1 to 80 kGy depending on concentration of quartz powder, indicating their suitability for low and high dose gamma radiation applications. Also it was found that quartz rod exhibits a linear dose response in the dose regions 0.1-2.34 and 2.34-26 kGy at optimum EPR parameters. The dosimeter response was assessed using the peak-to-peak amplitude of the first-derivatives EPR spectrum. Its EPR signal was found unchanged in shape with different doses and different concentrations. A signal line spectrum attributed to the E-center was observed after irradiation, and this radical is insensitive to temperature, light independence as well as it have a very low decay (4.768 % per year). The overall uncertainty for quartz rod dosimeters at 2σ (σ is standard deviation) was found to be 3.8436 %. The dosimetric parameters, e. g. dose response, effect of temperature during irradiation on response as well as pre- and post-irradiation stability at different storage conditions

  9. Accuracy of helium accumulation fluence monitor for fast reactor dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Ito, Chikara; Aoyama, Takafumi [Power Reactor and Nuclear Fuel Development Corp., Oarai, Ibaraki (Japan). Oarai Engineering Center

    1998-03-01

    A helium (He) accumulation fluence monitor (HAFM) has been developed for fast reactor dosimetry. In order to evaluate the measurement accuracy of neutron fluence by the HAFM method, the HAFMs of enriched boron (B) and beryllium (Be) were irradiated in the Fast Neutron Source Reactor `YAYOI`. The number of He atoms produced in the HAFMs were measured and compared with the calculated values. As a result of this study, it was confirmed that the neutron fluence could be measured within 5 % by the HAFM method, and that met the required accuracy for fast reactor dosimetry. (author)

  10. Dosimetry in dentistry.

    Science.gov (United States)

    Asha, M L; Chatterjee, Ingita; Patil, Preeti; Naveen, S

    2015-01-01

    The purpose of this paper was to review various dosimeters used in dentistry and the cumulative results of various studies done with various dosimeters. Several relevant PubMed indexed articles from 1999 to 2013 were electronically searched by typing "dosimeters", "dosimeters in dentistry", "properties of dosimeters", "thermoluminescent and optically stimulated dosimeters", "recent advancements in dosimetry in dentistry." The searches were limited to articles in English to prepare a concise review on dental dosimetry. Titles and abstracts were screened, and articles that fulfilled the criteria of use of dosimeters in dental applications were selected for a full-text reading. Article was divided into four groups: (1) Biological effects of radiation, (2) properties of dosimeters, (3) types of dosimeters and (4) results of various studies using different dosimeters. The present review on dosimetry based on various studies done with dosimeters revealed that, with the advent of radiographic technique the effective dose delivered is low. Therefore, selection of radiological technique plays an important role in dental dose delivery.

  11. Evaluation of Usefulness on In-vivo Diode Dosimetry for Measuring the Tumor Dose of Oral Cancer Patient

    International Nuclear Information System (INIS)

    Na, Kyung Su; Lee, Je Hee; Park, Heung Deuk

    2005-01-01

    This test is designed to identify the validity of treatment plan by implementing real-time dosimetry by means of dose that is absorbed into PTV and OAR when preparing doses of 3D and POP plans. In treatment. error can be calculated be comparing Exp. Dose with the actual dose, which has been converted from 'the reading value obtained by placing diode detector on the area to be measured'. Same test can be repeated using Alderson-Rando phantom. Errors were found: A patient(POP plan): 197.6/199=-1.2%, B patient(3D-plan): 199.9/198.7=+0.6%, C patient: 196/200=-1.5%. In addition, considering the resulted value of measuring OAR besides target-dose for C patient showed 96/200, representing does of 47%, the purpose of protection was judged to be duly accomplished. Also it was acknowledged the resulted value of -3.7% met the targeted dose within the range of ±5%. Aimed for identifying the usefulness of pre-treatment dose measurement using diode detector, this test was useful to evaluate the validity of curing because it resulted in the identification of category to be protected as well as t dose. Moreover, it is thought to have great advantage in ascertaining the dose of target, dose of which is not calculated yet. Similar to L-gram before treatment, this test is thought to be very effective so that it can bring great advantages in the aspects such as validity of curing method and post-treatment plan as well.

  12. An innovative in vitro device providing continuous low doses of gamma-rays and altered gravity mimicking spatial exposure: dosimetry study

    Science.gov (United States)

    Collin, Laetitia; Courtade-Saidi, Monique; Pereda Loth, Veronica; Franceries, Xavier; Afonso, Anne Sophie; Ayala, Alicia; Bardies, Manuel

    Astronauts are exposed to microgravity and chronic irradiation. Experimental conditions combining these two factors are difficult to reproduce on earth. The aim of our study was to create an experimental device able to combine chronic irradiation and altered gravity that may be used for cell cultures or plant models. Irradiation was provided with Thorium nitrate powder, conditioned in several bags in order to obtain a sealed source. This source was placed in an incubator. Lead leafs covered the internal walls of the incubator in order to protect people outside from radiations. Cell plates or plants seeds could be placed on direct contact with the source or at different distances above the source. Moreover, a random positioning machine (RPM) was placed inside the incubator and positioned on the source. The dosimetry was performed for different experimental conditions. The activity of the source was established considering all the decay chain of thorium. The spectrum of the source calculated according to the natural decrease of radioactivity was compared with gamma spectrometry (InterceptorTM) and showed a very good adequacy. The fluence evaluated with a gamma detector was closed to the theoretical fluence evaluated with our model, attesting that the source was uniformly distributed. Dosimetry was performed with radiophotoluminescent dosimeters (RPL) placed for one month exposition in different locations (x and y axis) inside cell culture dishes. When the dishes were placed directly on the source, we obtained a dose rate from 660 to 983 mSv/year, while it was between 80 to 127 mSv/year at a distance of 14.5 cm above the source. Using the RPM placed on the source we reached median dose rate levels of 140 mSv/year. In conclusion, we have elaborated a new device allowing the combination of chronic radiation exposure and altered gravity. This device can be used by researchers interested in the field of space biology.

  13. Evaluation of the 115In(n,n)/sup 115m/In reaction for the ENDF/B-V dosimetry file

    International Nuclear Information System (INIS)

    Smith, D.L.

    1976-12-01

    An evaluation of the 115 In(n,n')/sup 115m/In reaction for the ENDF/B-V Dosimetry File is presented. This evaluation is based entirely on reported experimental differential data. Several data sets were renormalized prior to the evaluation in order to take into account recent adjustments in corresponding standard cross sections and in other nuclear parameters used for derivation of cross sections. The present evaluation is compared with the corresponding ENDF/B-IV evaluation. The value of the spectrum-average cross section for the standard neutron field resulting from thermal-neutron fission of 235 U has been computed for this reaction using cross section values from the present evaluation. This computed cross section compares favorably with the result of a recent evaluation of integral data

  14. Correlation between prostate brachytherapy-related urethral stricture and peri-apical urethral dosimetry: A matched case–control study

    International Nuclear Information System (INIS)

    Earley, James J.; Abdelbaky, Ather M.; Cunningham, Melanie J.; Chadwick, Eliot; Langley, Stephen E.M.; Laing, Robert W.

    2012-01-01

    Background and purpose: Radiation dose to the bulbomembranous urethra has been shown to correlate with urethral stricture formation. This retrospective case–control study was designed to explore the relationship between dose to the apical/peri-apical regions of the urethra and development of brachytherapy (BXT)-related urethral stricture. Materials and methods: Cases were patients who developed urethral stricture after treatment with BXT as monotherapy and who had urethral dosimetry post-implant. Each case was matched with a control that had not developed urethral stricture. Dosimetry was compared between cases and controls. Results: Twenty-three cases were pair matched with 23 controls. There were no significant differences between the two groups in terms of age, presenting Prostate Specific Antigen (PSA), International Prostate Symptom Score (IPSS) or Gleason score. The dose delivered to the peri-apical and apical urethra was significantly higher for cases when compared with controls (peri-apical urethra: mean V 150 1.1 Vs 0.8 cc [p = 0.02]; apical urethra: mean dose 200 Vs 174 Gy [p = 0.01]). The distance from the prostate apex to isodose lines was also found to be significant in predicting stricture formation. Conclusion: There was evidence to suggest that the development of BXT-related stricture was associated with radiation dose at the apical and peri-apical urethra. Attention to the dose delivered to those areas may minimise the risk of developing such morbidity.

  15. Technical requirements for implementation of an individual monitoring service for evaluation of operational quantity HP(10) using thermoluminescent dosimetry; Requisitos tecnicos para a implantacao de um servico de monitoracao individual externa de corpo inteiro para fotons utilizando dosimetria termoluminescente

    Energy Technology Data Exchange (ETDEWEB)

    Francisco, Adelaide Benedita Armando

    2016-11-01

    This work aims to establish technical requirements for the development of a TLDs system for the assessment of operational quantity H{sub P}(10), in order to implement an external individual monitoring service in countries who do not have. This allows a better understanding of the technic and the thermoluminescent dosimetry system, thus contributing to identify the technical criteria to be followed by a dosimetry laboratory and evaluation of the dosimetric system performance. For this, the review of the specific literature of the dosimetry field was conducted and later the type and performance tests that must be followed by a dosimetric system were reproduced in practice. In additional was made a analysis of internationals standards norms and the technical regulation used in Brazil, to define the essentials type testes to a dosimetric system. To check the performance of a dosimetry system, a performance analysis of the Brazilian TLDs system was carried out over the past 6 years using the trumpet curve, where it was observed that most of TLDs system, in this review period, were approved and have excellent performance. The technical requirements for the development of a thermoluminescent dosimetry system ensure that the system provides technically reliable results and allow demonstration of compliance with the standard criteria established by national and international standards, and the implementation of the dosimetry system, is verified the compliance of the annual doses limits set for occupationally exposed. (author)

  16. A thin alanine-polyethylene film dosimetry system with diffuse reflection spectrophotometric evaluation

    International Nuclear Information System (INIS)

    Zagorski, Z.P.; Rafalski, A.

    1995-01-01

    Characteristics of a new alanine dosimeter in the shape of a thin film, with the measurement of optical absorption of the CH 3 CHCOO - radical is described. That type of dosimeter, ALA/DRS (for diffuse reflection spectrophotometry) is compared, to an alanine dosimeter with EPR evaluation (ALA/EPR for short). In many respects the simple ALA/DRS version, as the alanine-polyethylene composite is superior. The paper shows the importance of the new experimental approach to free radical research in solid state radiation chemistry. (author). 7 refs., 3 figs

  17. Feasibility studies of using thin entrance window photodiodes for clinical electron beam dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Nascimento, Cristina R.; Asfora, Viviane K.; Barros, Vinicius S.M.; Gonçalves, Josemary A.C.; Andrade, Lucas F.R.; Khoury, Helen J.; Bueno, Carmen C., E-mail: vsmdbarros@gmail.com, E-mail: vikhoury@gmail.com, E-mail: hjkhoury@gmail.com, E-mail: cristinaramos@smartsat.com.br, E-mail: josemary@ipen.br, E-mail: ccbueno@ipen.br [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil); Instituto Federal de Educação, Ciência e Tecnologia de Pernambuco (IFPE), Recife-PE (Brazil). Departamento de Energia Nuclear; Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Santa Casa de Misericórdia de Itabuna, BA (Brazil)

    2017-11-01

    The response of the commercial XRA-24 PIN photodiode (5.76 mm{sup 2} active area) for clinical electron beam dosimetry covering the range of 8-12 MeV was investigated. Within this energy range, the charge generated in the diode's sensitive volume is linearly dependent on the absorbed dose up to 320 cGy. However, charge sensitivity coefficients evidenced that the dose response of the diode is slightly dependent on the electron beam energy. Indeed, the diode's energy dependence was within 8.5% for 8-12MeV electron beams. On the other hand, it was also observed an excellent repeatability of these results with a variation coefficient (VC) lower than 0.4%, which is within the 1% tolerance limit recommended by the AAPM TG-62. Furthermore, the agreement between the percentage depth dose profiles (PDD) gathered with the diode and the ionization chamber allowed achieving the electron beam quality within 1% of that obtained with the ionization chamber. Based on these results, the photodiode XRA-24 can be a reliable and inexpensive alternative for electron beams dosimetry. (author)

  18. Feasibility studies of using thin entrance window photodiodes for clinical electron beam dosimetry

    International Nuclear Information System (INIS)

    Nascimento, Cristina R.; Asfora, Viviane K.; Barros, Vinicius S.M.; Gonçalves, Josemary A.C.; Andrade, Lucas F.R.; Khoury, Helen J.; Bueno, Carmen C.

    2017-01-01

    The response of the commercial XRA-24 PIN photodiode (5.76 mm 2 active area) for clinical electron beam dosimetry covering the range of 8-12 MeV was investigated. Within this energy range, the charge generated in the diode's sensitive volume is linearly dependent on the absorbed dose up to 320 cGy. However, charge sensitivity coefficients evidenced that the dose response of the diode is slightly dependent on the electron beam energy. Indeed, the diode's energy dependence was within 8.5% for 8-12MeV electron beams. On the other hand, it was also observed an excellent repeatability of these results with a variation coefficient (VC) lower than 0.4%, which is within the 1% tolerance limit recommended by the AAPM TG-62. Furthermore, the agreement between the percentage depth dose profiles (PDD) gathered with the diode and the ionization chamber allowed achieving the electron beam quality within 1% of that obtained with the ionization chamber. Based on these results, the photodiode XRA-24 can be a reliable and inexpensive alternative for electron beams dosimetry. (author)

  19. Personnel neutron dosimetry

    International Nuclear Information System (INIS)

    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

  20. Evaluation of a liquid ionization chamber for relative dosimetry in small and large fields of radiotherapy photon beams

    International Nuclear Information System (INIS)

    Benítez, E.M.; Casado, F.J.; García-Pareja, S.; Martín-Viera, J.A.; Moreno, C.; Parra, V.

    2013-01-01

    Commissioning and quality assurance of radiotherapy linear accelerators require measurement of the absorbed dose to water, and a wide range of detectors are available for absolute and relative dosimetry in megavoltage beams. In this paper, the PTW microLion isooctane-filled ionization chamber has been tested to perform relative measurements in a 6 MV photon beam from a linear accelerator. Output factors, percent depth dose and dose profiles have been obtained for small and large fields. These quantities have been compared with those from usual detectors in the routine practice. In order to carry out a more realistic comparison, an uncertainty analysis has been developed, taking type A and B uncertainties into account. The results present microLion as a good option when high spatial resolution is needed, thanks to its reduced sensitive volume. The liquid filling also provides a high signal compared to other detectors, like that based on air filling. Furthermore, the relative response of microLion when field size is varied suggests that this detector has energy dependence, since it is appreciated an over-response for small fields and an under-response for the large ones. This effect is more obvious for field sizes wider than 20 × 20 cm 2 , where the differences in percent depth dose at great depths exceed the uncertainties estimated in this study. - Highlights: • When high spatial resolution is required the results confirm the suitability of the liquid chamber. • Some energy dependence of the liquid detector can be appreciated in OFs and PDDs for small and large fields. • For field sizes >20 × 20 cm 2 , the differences in PDDs at great depths exceed the uncertainties estimated. • Some drawbacks should be considered: the time to reach stability, the high voltage supply required and the acquiring cost

  1. Evaluation of the response of thermoluminescent detectors in clinical beams dosimetry using different phantoms; Avaliacao da resposta de detectores termoluminescentes na dosimetria de feixes clinicos utilizando diferentes objetos simuladores

    Energy Technology Data Exchange (ETDEWEB)

    Matsushima, Luciana Cardoso

    2010-07-01

    Radiotherapy is one of the three principal treatment modalities used in the treatment of malignant diseases such as cancer, the other two are chemotherapy and radiosurgery. In contrast to other medical specialties that rely mainly on the clinical knowledge and experience of medical specialists, radiotherapy, with its use of ionizing radiation in treatment of cancer, relies heavily on modern technology and the collaborative efforts of several professionals whose coordinated team approach greatly influences the outcome of the treatment. In the area of clinical dosimetry, an efficient and accurate calibration of the radiation beam ensures knowledge of the radiation dose delivered to the patient, allowing thus the success of radiotherapy. This study aims to compare the thermoluminescent response of calcium sulfate doped with dysprosium (CaSO{sub 4}:Dy) dosimeters produced by IPEN (6 mm in diameter and 0,8 mm tick) with the response of lithium fluoride (3,15 x 3,15 x 0,9 mm{sup 3}) doped with magnesium and titanium (LiF:Mg,Ti) in dosimetry of clinical photons (6 and 15 MV) and electrons beams (6 and 9 MeV) using solid water (RMI-457), water and PMMA phantoms. Initially, the dose-response curves were obtained for irradiation in cobalt-60 gamma radiation source in air (PMMA plates) and under electronic equilibrium conditions and for clinical electrons and photons beams at depth of maximum dose. The sensitivities of the thermoluminescent dosimeters were also evaluated and the values of their reproducibilities and intrinsic efficiency were determined for the response to different types of phantoms and radiation energy. The obtained results indicate that the main advantage of CaSO{sub 4}:Dy dosimeters is the enhanced sensitivity to radiation doses measured for {sup 60}Co, photons and electrons beams, thus representing a viable alternative for application in dosimetry in the radiotherapy area. (author)

  2. For information: Individual dosimetry service

    CERN Document Server

    2004-01-01

    The service has noticed that there are dosimeter holders who have changed their activities and thus have no longer need of dosimeter as a permanent basis in their work (persons who go rarely to the controlled areas). The reduction of persons in the regular distribution list of dosimeters will lighten the work of the service (distribution, evaluation and consolidation of doses) as well as the work of the distributors, needless to say the economical input this would have for CERN. For the persons who only need a dosimeter temporarily we would like to remind that there is a quick and simple procedure to have one immediately from the Individual Dosimetry Service. Please contact the service (dosimetry.service@cern.ch) if you do not need a dosimeter regularly. Thank you for your cooperation. http://cern.ch/rp-dosimetry

  3. Personnel neutron dosimetry at Department of Energy facilities

    International Nuclear Information System (INIS)

    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

  4. Radiation protection dosimetry in medicine - Report of the working group n.9 of the European radiation dosimetry group (EURADOS) - coordinated network for radiation dosimetry (CONRAD - contract EC N) fp6-12684

    International Nuclear Information System (INIS)

    2009-01-01

    This report present the results achieved within the frame of the work the WP 7 (Radiation Protection Dosimetry of Medical Staff) of the coordination action CONRAD (Coordinated Network for Radiation Dosimetry) funded through the 6. EU Framework Program. This action was coordinated by EURADOS (European Radiation Dosimetry Group). EURADOS is an organization founded in 1981 to advance the scientific understanding and the technical development of the dosimetry of ionising radiation in the fields of radiation protection, radiobiology, radiation therapy and medical diagnosis by promoting collaboration between European laboratories. WP7 coordinates and promotes European research for the assessment of occupational exposures to staff in therapeutic and diagnostic radiology workplaces. Research is coordinated through sub-groups covering three specific areas: 1. Extremity dosimetry in nuclear medicine and interventional radiology: this sub-group coordinates investigations in the specific fields of the hospitals and studies of doses to different parts of the hands, arms, legs and feet; 2. Practice of double dosimetry: this sub-group reviews and evaluates the different methods and algorithms for the use of dosemeters placed above and below lead aprons in large exposure during interventional radiology procedures, especially to determine effective doses to cardiologists during cardiac catheterization; and 3. Use of electronic personal dosemeters in interventional radiology: this sub-group coordinates investigations in laboratories and hospitals, and intercomparisons with passive dosemeters with the aim to enable the formulation of standards. (authors)

  5. Evaluation of personal dosimetry in abdominal aorta endo prosthesis procedures; Avaliacao da dosimetria pessoal em procedimentos de endoproteses de aorta abdominal

    Energy Technology Data Exchange (ETDEWEB)

    Bacchim Neto, Fernando A.; Alves, Allan F.F.; Freitas, Carlos C.M. de; Pina, Diana R. [Universidade Estadual Paulista Julio de Mesquita Filho (FMB/UNESP), Botucatu, SP (Brazil). Faculdade de Medicina

    2016-07-01

    The objective of this paper is to evaluate the currently dosimetry technique employed in the medical staff during interventional radiology procedures. Thermoluminescent dosimeters were positioned in different regions of the primary interventionist during procedures of stent graft in abdominal aortic aneurysms. The equivalent dose rate profile shows a tendency of difference between dose rate found in the chest in relation to the abdomen, hands and feet. Statistically, dose rates found in the hands differ from those found in the chest with p=0.05. These results suggest that only a dosimeter placed on the chest does not describe faithfully the radiation doses to which these professionals are occupationally exposed. (author)

  6. Dosimetry for radiation processing

    DEFF Research Database (Denmark)

    Miller, Arne

    1986-01-01

    During the past few years significant advances have taken place in the different areas of dosimetry for radiation processing, mainly stimulated by the increased interest in radiation for food preservation, plastic processing and sterilization of medical products. Reference services both...... and sterilization dosimetry, optichromic dosimeters in the shape of small tubes for food processing, and ESR spectroscopy of alanine for reference dosimetry. In this paper the special features of radiation processing dosimetry are discussed, several commonly used dosimeters are reviewed, and factors leading...

  7. Individual dosimetry in a radiotherapy department - evaluation between 1997 and 2004

    International Nuclear Information System (INIS)

    Macedo, S.C.; Jorge, L.; Alves, J.

    2005-01-01

    Full text: The occupational exposure is the exposure of workers due to their work. With the individual monitorization of the external radiation it is possible to get an approximated value of the effective dose and of the equivalent dose to the skin. The effective doses evaluation allows us to verify if these values are bellow the threshold established by law (a Portuguese law from 1990 established levels under 50 mSv/year for professionals and another law from 1997 established levels under 0,4 mSv/week, which is equivalent to 20 mSv/year, also for professionals). Methods and materials: we analyzed the values of the TLD dosimeters used by the workers during their professional activity between 1997 and 2004, in a Radiotherapy Department. Results: we separed the workers by professional groups and analyzed the equivalent dose in depth achieved (mSv/year). The workers were separed by physicians, medical physicists, technicians, nurses, helpers and secretaries. Conclusions: from the analysis of the results it is possible to demonstrate that the equivalent dose in depth achieved by the workers are under the threshold established and that we work under good conditions of radiation protection. (author)

  8. Dosimetry of internal emitting: principles and perspectives of the MIRD technology

    International Nuclear Information System (INIS)

    Ferro F, G.

    1999-01-01

    The development of the radiopharmaceutical technology have multiplied the number of radioisotopes with applications in therapeutical nuclear medicine so known as Directed radiotherapy. Assuming the radiation is capable to produce noxious effects in the biological systems, it is important to evaluate appropriately the risks and benefits of the administration of radioactive agents in the patient. The outstanding parameter in this evaluation is the absorbed dose, which is product of the radiation emitted by a radionuclide that is localized or distributed to the interior of the human body in study and whose its estimation helps to predict the efficacy of the treatment. The scheme generalized of MIRD, it was formulated from thirty years ago for evaluating the interior dosimetry at level of organs.The finality of this work is to show the basic principles of the MIRD methodology and its perspectives using innovator tools as the dosimetry for dynamic masses, in particular the personnel dosimetry for the organs of each patient, the dosimetry for the small structures inside the organs (sub organic dosimetry), the distributions of doses in three dimensions (S voxel), the dosimetry at cellular level and the quantitative acquisition of pharmaceutical data. (Author)

  9. Evaluation of DNA dosimetry to assess ozone-mediated variability of biologically harmful radiation in Antarctica

    NARCIS (Netherlands)

    George, AL; Peat, HJ; Buma, AGJ

    In this study we investigated the use of a DNA dosimeter to accurately measure changes in ultraviolet B radiation (UVBR; 280-315 nm) under Antarctic ozone hole conditions. Naked DNA solution in quartz tubes was exposed to ambient solar radiation at Rothera Research Station, Antarctica, between

  10. Evaluation of Deltamethrin Kinetics and Dosimetry in the Maturing Rat using a PBPK Model

    Science.gov (United States)

    Immature rats are more susceptible than adults to the acute neurotoxicity of pyrethroid insecticides like deltamethrin (DLM). A companion kinetics study revealed that blood and brain levels of the neuroactive parent compound were inversely related to age in rats 10, 21, 40 and 90...

  11. Clinical application of in vivo dosimetry for external telecobalt machine

    International Nuclear Information System (INIS)

    Mohammed, H. H. M.

    2011-01-01

    In external beam radiotherapy quality assurance is carried out on the individual components of treatment chain. The patient simulating device, planning system and treatment machine are tested regularly according to set protocols developed by national and international organizations. Even thought these individual systems are not tested for errors which can be made in the transfer between the systems. The best quality assurance for the treatment planning chain. In vivo dosimetry is used as a quality assurance tool for verifying dosimetry as either the entrance or exit surface of the patient undergoing external beam radiotherapy. It is a proven reliable method of checking overall treatment accuracy, allowing verification of dosimetry and dose calculation as well as patient treatment setup. Accurate in vivo dosimetry is carried out if diodes and thermoluminescence dosimeters (TLDs). the main detector types in use for in vivo dosimetry, are carefully calibrated and the factors influencing their sensitivity are taken into account. The aim of this study was to verify the response of TLDs type (LiF: Mg, Cu, p) use in radiotherapy, to establish calibration procedure for TLDs and to evaluate entrance dose obtained by the treatment planning system with measured dose using thermoluminescence detectors. Calibration of TLDs was done using Cobalt-60 teletherapy machine, linearity and calibration factors were determined. Measurements were performed in random phantom for breast irradiation (for the breast irradiation ( For the breast irradiation technique considered, wedge field was used). All TLDs were processed and analyzed at RICK. In vivo dosimetry represents a technique that has been widely employed to evaluate the dose to the patient mainly in radiotherapy. Thermoluminescent dosimeters are considered the gold stander for in vivo dosimetry and do not require cables for measurements which makes them ideal for mail based studies and have no dose rate or temperature dependence

  12. Criticality accidents in solution (CRAC and SILENE programmes) and complementary studies of accidents; radiation dosimetry in human organism during the CRAC programme

    International Nuclear Information System (INIS)

    Barbry, M.; Dousset, M.

    C.R.A.C. (CRiticality occurring ACcidentally) programme is intended to study experimentally the development of a criticality accident as it could occur when handling solutions of fissile material as well as the radiological consequences of such an accident. The fissile matter solutions have been chosen (a) for practical considerations of use and (b) because the probability of an accident occurring seems greater with this type of environment, as the known accidents have shown. The programme is twofold: study of accident physics: form of the evolution (peak, plateau, oscillations, boil up of solutions) the most probable maximum power, minimal power, flux and radiation spectra emitted, freed energy, associated effects, radiolysis, constraints, etc., study of radiological consequences: area dosimetry, individual dosimetry, radiobiological studies, etc. Additional criticality Accident experiments have been and continue to be made on the SILENE reactor in the following principal domains: determination of the emission rate of gaseous fission products and aerosols, area dosimetry and health dosimetry in the presence of shields around the core to vary the neutron and gamma components of the radiation field. Improvement in the knowledge of certain particular aspects of the power excursion, radiolysis gas and pressure wave, experiments of the ''boiling'' type [fr

  13. Internal dosimetry - its evolution and new trends

    International Nuclear Information System (INIS)

    Bertelli, Luiz

    1997-01-01

    This paper presents some discussions on the developments and trends of metabolic models and dosimetry and their associated parameters, which have been adopted by ICRP to evaluate intakes of radionuclides

  14. Dosimetry study of East Kazakhstan residents by tooth enamel EPR spectroscopy

    Science.gov (United States)

    Zhumadilov, Kassym; Ivannikov, Alexander; Skvortsov, Valeriy; Stepanenko, Valeriy; Rakhypbekov, Tolebay; Hoshi, Masaharu

    2017-11-01

    The tooth enamel electron paramagnetic resonance (EPR) dosimetry method was used to determine accidental doses of population of settlements in the vicinity of the Semipalatinsk Nuclear Test Site (SNTS), Kazakhstan. The influence of four explosions to the populations was included into this report. The distances between investigated settlements and Ground Zero (SNTS) are in the range of 70-200 km from SNTS. Most of settlements (Dolon, Mostik, Bodene, Cheremushki, Kanonerka) are located near the central axis of radioactive fallout trace from the most contaminating surface nuclear test, which was conducted in 29, August 1949. The other settlements located close to radioactive fallout trace result in a surface nuclear tests in 24, August 1956 (Ust-Kamenogorsk, Znamenka, Shemonaikha, Glubokoe, Tavriya, Gagarino), in 12 august 1953 (Sarzhal) and in 7, August 1962 (Akzhar, Kurchatov, Begen, Semenovka, Buras, Grachi). Tooth samples were extracted according to medical recommendations in a course of ordinary dental treatment.

  15. Evaluation of water-mimicking solid phantom materials for use in HDR and LDR brachytherapy dosimetry

    Science.gov (United States)

    Schoenfeld, Andreas A.; Thieben, Maike; Harder, Dietrich; Poppe, Björn; Chofor, Ndimofor

    2017-12-01

    In modern HDR or LDR brachytherapy with photon emitters, fast checks of the dose profiles generated in water or a water-equivalent phantom have to be available in the interest of patient safety. However, the commercially available brachytherapy photon sources cover a wide range of photon emission spectra, and the range of the in-phantom photon spectrum is further widened by Compton scattering, so that the achievement of water-mimicking properties of such phantoms involves high requirements on their atomic composition. In order to classify the degree of water equivalence of the numerous commercially available solid water-mimicking phantom materials and the energy ranges of their applicability, the radial profiles of the absorbed dose to water, D w, have been calculated using Monte Carlo simulations in these materials and in water phantoms of the same dimensions. This study includes the HDR therapy sources Nucletron Flexisource Co-60 HDR (60Co), Eckert und Ziegler BEBIG GmbH CSM-11 (137Cs), Implant Sciences Corporation HDR Yb-169 Source 4140 (169Yb) as well as the LDR therapy sources IsoRay Inc. Proxcelan CS-1 (131Cs), IsoAid Advantage I-125 IAI-125A (125I), and IsoAid Advantage Pd-103 IAPd-103A (103Pd). Thereby our previous comparison between phantom materials and water surrounding a Varian GammaMed Plus HDR therapy 192Ir source (Schoenfeld et al 2015) has been complemented. Simulations were performed in cylindrical phantoms consisting of either water or the materials RW1, RW3, Solid Water, HE Solid Water, Virtual Water, Plastic Water DT, Plastic Water LR, Original Plastic Water (2015), Plastic Water (1995), Blue Water, polyethylene, polystyrene and PMMA. While for 192Ir, 137Cs and 60Co most phantom materials can be regarded as water equivalent, for 169Yb the materials Plastic Water LR, Plastic Water DT and RW1 appear as water equivalent. For the low-energy sources 106Pd, 131Cs and 125I, only Plastic Water LR can be classified as water equivalent.

  16. Studies of P(VDF-HFP) copolymer applied to gamma dosimetry

    International Nuclear Information System (INIS)

    Liz, Otavio S.R.; Medeiros, Adriana S.

    2011-01-01

    When polymeric materials are irradiated by ionizing radiation, the effects are roughly divided into two types, degradation (chain scission) and chain link (crosslinking). These effects are normally identified by spectroscopic analysis in the UV-Vis and Infrared region. Recently, the intensities of optical absorption in the ultraviolet visible region (273 nm) due to radio-induction of conjugated C = C bonds in P(VDF-TrFE) copolymers have been successfully used for high dose gamma dosimetry, for doses ranging from 0.1 to 200 kGy. In this context, there is now an interest to conduct a similar systematic investigation of another fluorinated copolymer of PVDF, the poly(fluorovinylidene-co-hexafluoropropylene) [P(VDF-HFP)], not only in the UV-VIS region but also in the near and mid-infrared region. The copolymer used was obtained by randomly adding 10% molar of [CF2- CF-CF3] monomers in the [CH2-CF2]n main chain of PVDF homopolymer. Preliminary results have shown that the irradiated copolymer has characteristic absorption bands originated by irradiation in the FTIR spectrum. It was found that the 1852 cm -1 band, associated with C = O bonds, have a linear correlation with the absorbed dose for doses ranging from 10 to 750 kGy. The absorption band at 1729 cm -1 , associated to chain oxidation (C = O), has shown a similar behavior and can be used to measure doses from 100 to 1000 kGy. These results indicate that the FTIR absorption bands of gamma irradiated P (VDF-HFP) have great potential to be used in high dose dosimetry, without the addition of dyes. (author)

  17. Radiation fields, dosimetry, biokinetics and biophysical models for cancer induction by ionising radiation 1996-1999. Executive summary

    International Nuclear Information System (INIS)

    Jacob, P.; Paretzke, H.G.; Roth, P.

    2000-01-01

    The Association Contract covers a range of research domains that are important to the Radiation Protection Research Action, especially in the areas 'Evaluation of Radiation Risks' and 'Understanding Radiation Mechanisms and Epidemiology'. Three research projects concentrate on radiation dosimetry research and two projects on the modelling of radiation carcinogenesis. The following list gives an overview on the topics and responsible scientific project leaders of the Association Contract: Study of radiation fields and dosimetry at aviation altitudes. Biokinetics and dosimetry of incorporated radionuclides. Dose reconstruction. Biophysical models for the induction of cancer by radiation. Experimental data for the induction of cancer by radiation of different qualities. (orig.)

  18. High-resolution gel dosimetry using flat-panel detector cone-beam computed tomography: preliminary study.

    Science.gov (United States)

    Huang, Kuo-Ming; Huang, Tzung-Chi; Tsai, Chia-Jung; Lu, Kun-Mu; Chen, Liang-Kuang; Wu, Tung-Hsin

    2010-01-01

    This study compares the dose response of irradiated polymer gel with acrylic and styrofoam housing while applying multi-detector CT (MDCT) and cone-beam CT (CBCT). The dose response for MDCT and CBCT, while using an acrylic phantom is 1.34 and 0.67 DeltaHU Gy(-1), respectively, and becomes 1.54 and 0.84 DeltaHU Gy(-1) while using styrofoam, suggesting styrofoam is the better housing material. While the dose response of MDCT is better than that of CBCT, CBCT is yet a promising 3D dosimetry technique, given its potentially better spatial resolution and sensitive dose interpretation capability. Copyright 2009 Elsevier Ltd. All rights reserved.

  19. Biological Dosimetry of X-rays by micronuclei study; Dosimetria Biologica de rayos-X mediante el estudio de micronucleos

    Energy Technology Data Exchange (ETDEWEB)

    Gomez, E.; Silva, A.; Navlet, J.

    1991-07-01

    Biological dosimetry consists of estimating absorbed doses for people exposed to radiation by mean biological methods. Several indicators used are based in haematological, biochemical an cytogenetics data, although nowadays without doubt, the cytogenetic method is considered to be the most reliable, in this case, the study of micronuclei in peripheral blood lymphocytes citokinetics blocked can be related to absorbed dose through an experimental calibration curve. An experimental dose-response curve, using micronuclei assay for X-rays at 250 kVp, 43,79 rads/min and temperature 37 degree centigree has been produced. Experimental data is fitted to model Y=C+ {alpha}D+BD''2 where Y is the number of micronuclei per cell and D the dose. The curve is compared with those produced elsewhere. (Author) 24 refs.

  20. Evaluation of the thermoluminescent detector answers of CaSO4:Dy, LiF:Mg,Ti and micro LiF:Mg,Ti in photon clinical beams dosimetry using water simulator

    International Nuclear Information System (INIS)

    Matsushima, Luciana C.; Veneziani, Glauco R.; Campos, Leticia L.

    2011-01-01

    This paper perform the comparative study of thermoluminescent answer of calcium sulfate dosemeter doped with dysprosium (DaSO 4 :Dy) produced by the IPEN, Sao Paulo, with answer of lithium fluoride dosemeters doped with magnesium and titanium (LiF:Mg, Ti) in the dosimetry of clinical beams of photons (6 and 15 MV) by using water simulator object. Dose-answer curves were obtained for gamma radiation of cobalt-60 in the air and in conditions of electronic equilibrium (plate of PMMA), and clinical photons of CLINAC model 2100C accelerators of the two evaluated hospitals: Hospital das Clinicas of the Faculty of Medicine of Sao Paulo university and Hospital Albert Einstein. It was also evaluated the sensitivity and reproduction of the three dosemeters

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

    Directory of Open Access Journals (Sweden)

    Chechev Valery P.

    2016-01-01

    Full Text Available 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.

  2. 3D dosimetry estimation for selective internal radiation therapy (SIRT) using SPECT/CT images: a phantom study

    Science.gov (United States)

    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.

  3. Dosimeter with a photodiode base evaluation by IEC 731 standard and its application in X and gamma radiation field parameters determination and in vivo dosimetry

    International Nuclear Information System (INIS)

    Barbosa, Ricardo Amorim

    1998-03-01

    This work presents a dosimeter with a photodiode base, characterized as field class instrument, for determination of X and gamma radiation field parameters, which are specified in the ISO 4037-1 Standard, and for in vivo dosimetry. Three photodiode models performance, a commercially available (Siemens) and two special others (Hamamatsu), were compared with the ionization chamber's, using the limits established in the IEC 731 Standard as requirement. The long-term stability and the energy dependence tests have shown results higher than the limits but, in special situations, as X-ray beams monitoring, these deficiencies have no influence on the dosimeter performance. The photodiode Siemens has shown uncertainty of 7% for determination of the radiation field diameter, against 4% from the ionization chamber, 16% from the photographic emulsion and 18% from the TDL. At the rotation test, in a water phantom, none of the models has shown satisfactory results. However, using two photodiodes, it was obtained a dosimeter that overcomes these deficiencies, and it could be used for in vivo dosimetry. The relation between the output signal, from the proposed dosimeter, and the phantom depth, has shown agreement of 0,7% with the depth dose distribution curve. So, the dosimeter has shown its capability to evaluate the absorbed dose correctly. (author)

  4. Study of TSL and OSL properties of dental ceramics for accidental dosimetry applications

    Energy Technology Data Exchange (ETDEWEB)

    Veronese, Ivan, E-mail: ivan.veronese@unimi.i [Dipartimento di Fisica, Universita degli Studi di Milano and INFN Sezione di Milano, via Celoria 16, 20133 Milano (Italy); Galli, Anna [CNR-INFM, via Cozzi 53, 20125 Milano (Italy); Dipartimento di Scienza dei Materiali, Universita degli Studi di Milano Bicocca and INFN Sezione di Milano Bicocca, via Cozzi 53, 20125 Milano (Italy); Cantone, Marie Claire [Dipartimento di Fisica, Universita degli Studi di Milano and INFN Sezione di Milano, via Celoria 16, 20133 Milano (Italy); Martini, Marco [Dipartimento di Scienza dei Materiali, Universita degli Studi di Milano Bicocca and INFN Sezione di Milano Bicocca, via Cozzi 53, 20125 Milano (Italy); Vernizzi, Fabrizio; Guzzi, Gianpaolo [Italian Association for Metals and Biocompatibility Research - A.I.R.M.E.B., Milan (Italy)

    2010-01-15

    Interest is increasing in the development of new methodologies for accidental dose assessment, exploiting the luminescence and dosimetric properties of objects and materials which can be usually found directly on exposed subjects and/or in the contaminated area. In this work, several types of ceramics employed for dental prosthetics restoration, including both innovative materials used as sub-frames for the construction of the inner part of dental crowns (core), and conventional porcelains used for the fabrication of the external layer (veneer), were investigated with regard to their thermally and optically stimulated luminescence (TSL and OSL respectively) properties, in view of their potential application in accidental dosimetry. The sensitivity to ionizing radiation proved to strongly depend on the type and brand of ceramic, with minimum detectable dose ranging from few mGy up to several tens of mGy. A linear dose-response was observed for most of the samples. However, the luminescence signals were characterised by a significant fading, which has to be taken into account for a reliable accidental dose assessment after a radiation exposure event.

  5. Recent developments in neutron dosimetry and radiation damage calculations for fusion-materials studies

    International Nuclear Information System (INIS)

    Greenwood, L.R.

    1983-01-01

    This paper is intended as an overview of activities designed to characterize neutron irradiation facilities in terms of neutron flux and energy spectrum and to use these data to calculate atomic displacements, gas production, and transmutation during fusion materials irradiations. A new computerized data file, called DOSFILE, has recently been developed to record dosimetry and damage data from a wide variety of materials test facilities. At present data are included from 20 different irradiations at fast and mixed-spectrum reactors, T(d,n) 14 MeV neutron sources, Be(d,n) broad-spectrum sources, and spallation neutron sources. Each file entry includes activation data, adjusted neutron flux and spectral data, and calculated atomic displacements and gas production. Such data will be used by materials experimenters to determine the exposure of their samples during specific irradiations. This data base will play an important role in correlating property changes between different facilities and, eventually, in predicting materials performance in fusion reactors. All known uncertainties and covariances are listed for each data record and explicit references are given to nuclear decay data and cross sections

  6. Dosimetry study of split beam technique using megavoltage beams and its clinical implications. I

    International Nuclear Information System (INIS)

    Datta, R.; Mira, J.G.; Pomeroy, T.C.

    1979-01-01

    The problem of beam divergence and overlapping of adjacent fields in the treatment planning is well known. The use of split beam technique has been suggested as one way of addressing this problem. The present work reports a detailed dosimetry of this technique 60 Co beam (Theratron 780). The dose distributions at and near the junction plane between two adjacent fields were measured; they were compared with those for diverging fields (with and without gap on the skin). As an illustration, different treatment planning techniques for head and neck tumors and subsequent dose distributions are discussed. Our findings clearly indicate that the extension of penumbra near the geometrical edge of a split beam is considerably less than that of an open beam of the same field size. Consequently when two adjacent fields are used, the overdose at and near the junction plane is reduced greatly by the split beam. For head and neck tumors the split beam technique gives a much better dose distribution than any other conventional treatment techniques

  7. Quality assurance study for dosimetry of Radiation Therapy equipment in Saudi Arabia

    International Nuclear Information System (INIS)

    Al-Mokhlef, Jazi M.; Nabaz, Noori

    2003-01-01

    International standards address the accuracy of dose delivery for radiation therapy machines as well as quality assurance and staffing levels for radiation therapy centers. We performed absolute calibrations of gamma ,X-ray and electron radiotherapy beams in all radiation therapy centers in Saudi Arabia. We also assessed quality assurance and staffing levels Dosimetric measurements were made with a portable dosimetry system, which consisted of a calibrated Farmer ionization chamber and an electrometer, small water phantom, barometer and thermometer. Differences between the measured and the expected output (c Gy/MU or c Gy/min) were found to be in the range of -11%+5%. About 17% of radiotherapy beams were not within the acceptable tolerance level (+/-3%). Quality assurance in some radiation centers was poor and staffing levels were inadequate. We found poor compliance with internationally accepted tolerance levels for dose calibration of radiotherapy beams at radiation therapy centers in Saudi Arabia. Analysis of medical physics staffing revealed severe discrepancies from those recommended by international guidelines .We recommend that radiation therapy centers be adequately staffed with qualified medical physics personnel and that periodic audit programs be required a governmental body. (author)

  8. Dosimetry of inhaled plutonium-239 dioxide in rodent lung: a morphometric study

    Energy Technology Data Exchange (ETDEWEB)

    Rhoads, K.

    1979-06-01

    Morphometric analysis of rat and hamster lung did not demonstrate any extensive changes in lung composition or structure following inhalation exposure to /sup 239/Pu0/sub 2/ at levels near that for maximum tumor yield in rats. The problem of dosimetry for this compound thus appears to be relatively uncomplicated by any major radiation-induced pathological alterations in the lung. Rat and hamster lung were found to be similar in structure and composition, with few significant differences which could be directly related to the different tumor responses. The distribution of /sup 239/Pu0/sub 2/ particles was not uniform in all regions of the lung; thus estimation of the dose to specific tissues or regions within the lung requires a correction for this effect. Species differences were found for particle distribution in the subpleural region and major airways, and in the spatial association of particles, both of which may affect the tumor development process. These regions contain the principal target cells for tumor production and serve as foci for the origin of tumors. Different dose distributions within these regions may therefore explain, at least in part, the difference in tumor response to inhaled /sup 239/Pu0/sub 2/ for rats and hamsters.

  9. Preliminary study on biological dosimetry using alkaline single cell gel electrophoresis of human peripheral lymphocytes

    International Nuclear Information System (INIS)

    Liu Qingjie; Lu Xue; Feng Jiangbing; Chen Deqing; Chen Xiaosui

    2006-01-01

    Objective: To explore the feasibility of alkaline single cell gel electrophoresis (SCGE) in biological dosimetry of ionizing radiation. Methods: Normal peripheral blood samples from two healthy males were exposed to different doses coblat-60 gamma-rays, ranged from 0 to 5 Gy, and the tail length (TL) and Oliver tail moment (TM) of the lymphocytes were analyzed with SCGE. The dose-effect curves of TL and TM were fitted respectively. The TL and TM of lymphocytes for eight radiation workers were analyzed with SCGE, cumulative doses were estimated using the fitted TL and TM equations, and then compared with the recorded monitoring doses. Results: The TLs or TMs of normal human lymphocytes were increased with the irradiation doses, and its relationship can be fitted with a linear-quadratic equations: Y=13.59 + 20.87X - 2.27 X 2 for TL, and Y = 8.50 + 15.04X - 1.43X 2 for TM, respectively (Y denotes TL or TM value, X is radiation dose). The doses estimated with TM equation were closer to the recorded monitoring doses than that with TL equation. Conclusions: The TM in lymphocytes analyzed with SCGE is a promising radiation biological dosimeter. (authors)

  10. Use of electron paramagnetic resonance dosimetry with tooth enamel for retrospective dose assessment. Report of a co-ordinated research project

    CERN Document Server

    2002-01-01

    Electron paramagnetic resonance (EPR) dosimetry is a physical method for the assessment of absorbed dose from ionising radiation. It is based on the measurement of stable radiation induced radicals in human calcified tissues (primarily in tooth enamel). EPR dosimetry with teeth is now firmly established in retrospective dosimetry. It is a powerful method for providing information on exposure to ionising radiation many years after the event, since the 'signal' is 'stored' in the tooth or the bone. This technique is of particular relevance to relatively low dose exposures or when the results of conventional dosimetry are not available (e.g. in accidental circumstances). The use of EPR dosimetry, as an essential tool for retrospective assessment of radiation exposure is an important part of radioepidemiological studies and also provides data to select appropriate countermeasures based on retrospective evaluation of individual doses. Despite well established regulations and protocols for maintaining radiation pro...

  11. Reconstructive dosimetry of radiological accidents - study of a brazilian case of industrial gamma radiography; Dosimetria reconstrutiva de acidentes radiologicos - estudo de um caso brasileiro de gamagrafia industrial

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Francisco Cesar Augusto da; Hunt, John G.; Ramalho, Adriana [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil); Pinto, Livia M.F. Amalfi [ARCtest - Servicos Tecnicos de Inspecao e Manutencao Industrial Ltda., Paulinia, SP (Brazil)]. E-mail: protecao@arctest.com.br

    2002-07-01

    On May 2000, an industrial gamma radiography operator, during a maintenance work of a {sup 60}Co irradiator, has suffered a radiological accident with severe consequences to the left hand. The experts of the High Doses Analysis Group (GADE/IRD/CNEN) initiated the reconstructive dosimetry for the radiation dose estimation, in order to determine the real dose received by the operator, and to help the medical evaluation for prescribing the medical procedures for treatment of the involved victim. This paper presents the reconstructive dosimetry performed through the determination of the radiation doses of the operator, based on theoretical, experimental and computational methods. For the computer methods, a program for the calculation of external doses were used, based on the Monte Carlo method, and a human body simulator composed by voxels. The values of effective and equivalent doses are also presented which has caused severe lesions on the operator hand.

  12. Design and evaluation of a 1.1-GHz surface coil resonator for electron paramagnetic resonance-based tooth dosimetry.

    Science.gov (United States)

    Sugawara, Hirotaka; Hirata, Hiroshi; Petryakov, Sergey; Lesniewski, Piotr; Williams, Benjamin B; Flood, Ann Barry; Swartz, Harold M

    2014-06-01

    This paper describes an optimized design of a surface coil resonator for in vivo electron paramagnetic resonance (EPR)-based tooth dosimetry. Using the optimized resonator, dose estimates with the standard error of the mean of approximately 0.5 Gy were achieved with irradiated human teeth. The product of the quality factor and the filling factor of the resonator was computed as an index of relative signal intensity in EPR tooth dosimetry by the use of 3-D electromagnetic wave simulator and radio frequency circuit design environment (ANSYS HFSS and Designer). To verify the simulated results of the signal intensity in our numerical model of the resonator and a tooth sample, we experimentally measured the radiation-induced signals from an irradiated tooth with an optimally designed resonator. In addition to the optimization of the resonator design, we demonstrated the improvement of the stability of EPR spectra by decontamination of the surface coil resonator using an HCl solution, confirming that contamination of small magnetic particles on the silver wire of the surface coil had degraded the stability of the EPR spectral baseline.

  13. Thermoluminescence in medical dosimetry

    International Nuclear Information System (INIS)

    Rivera, T.

    2011-10-01

    The dosimetry by thermoluminescence (Tl) is applied in the entire world for the dosimetry of ionizing radiations specially to personal and medical dosimetry. This dosimetry method has been very interesting for measures in vivo because the Tl dosimeters have the advantage of being very sensitive in a very small volume and they are also equivalent to tissue and they do not need additional accessories (for example, cable, electrometer, etc.) The main characteristics of the diverse Tl materials to be used in the radiation measures and practical applications are: the Tl curve, the share homogeneity, the signal stability after the irradiation, precision and exactitude, the response in function with the dose and the energy influence. In this work a brief summary of the advances of the radiations dosimetry is presented by means of the thermally stimulated luminescence and its application to the dosimetry in radiotherapy. (Author)

  14. Radiation dosimetry by potassium feldspar

    Indian Academy of Sciences (India)

    Unknown

    Radiation dosimetry by potassium feldspar. ARUN PANDYA*, S G VAIJAPURKAR and P K BHATNAGAR. Defence Laboratory, Jodhpur 342 011, India. MS received 12 July 1999; revised 15 February 2000. Abstract. The thermoluminescence (TL) properties of raw and annealed feldspar have been studied for their.

  15. Radiation dosimetry by potassium feldspar

    Indian Academy of Sciences (India)

    The thermoluminescence (TL) properties of raw and annealed feldspar have been studied for their use in gamma dosimetry. The raw gamma exposed feldspar shows glow peaks at 120°C and 319°C. Gamma dose beyond 500 cGy can be measured without any significant fading even after 40 days of termination of ...

  16. Film dosimetry: a mathematical model

    International Nuclear Information System (INIS)

    Mafra Neto, F.

    1993-01-01

    A mathematical model for electromagnetic radiation dosimetry using photosensitive emulsions is presented. A Kodak odontological radiographic film was used for that purpose. Some properties such as energy dependence, reproductiveness and the characteristic curve were studied. A linear and energy-independent dosimeter for beams above 50 KeV was obtained by adding 1 mm lead filters. 4 refs, 8 figs, 2 tabs

  17. Calculation of the uncertainty of H{sub P} (10) evaluation for a thermoluminescent dosimetry system; Calculo da incerteza da avaliacao do H{sub P} (10) para um sistema de dosimetria termoluminescente

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, M.S.; Silva, E.R.; Mauricio, C.L.P., E-mail: max.das.ferreira@gmail.com [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2016-07-01

    Full interpretation of dose assessment only can be performed when the uncertainty of the measurement is known. The aim of this study is to calculate the uncertainty of the TL dosimetry system of the LDF/IRD for evaluation of H{sub P} (10) for photons. It has been done by experimental measurements, extraction of information from documents and calculation of uncertainties based on ISO GUM. Energy and angular dependence is the most important source to the combined u{sub c}(y) and expanded (U) uncertainty. For 10 mSv, it was obtained u{sub c}(y) = 1,99 mSv and U = 3,98 mSv for 95% of coverage interval. (author)

  18. Dosimetry of ionizing radiation

    International Nuclear Information System (INIS)

    Musilek, L.; Seda, J.; Trousil, J.

    1992-01-01

    The publication deals with a major field of ionizing radiation dosimetry, viz., integrating dosimetric methods, which are the basic means of operative dose determination. It is divided into the following sections: physical and chemical effects of ionizing radiation; integrating dosimetric methods for low radiation doses (film dosimetry, nuclear emulsions, thermoluminescence, radiophotoluminescence, solid-state track detectors, integrating ionization dosemeters); dosimetry of high ionizing radiation doses (chemical dosimetric methods, dosemeters based on the coloring effect, activation detectors); additional methods applicable to integrating dosimetry (exoelectron emission, electron spin resonance, lyoluminescence, etc.); and calibration techniques for dosimetric instrumentation. (Z.S.). 422 refs

  19. ESR dosimetry study on population of settlements nearby Ust-Kamenogorsk city, Kazakhstan.

    Science.gov (United States)

    Zhumadilov, Kassym; Ivannikov, Alexander; Zharlyganova, Dinara; Zhumadilov, Zhaxybay; Stepanenko, Valeriy; Apsalikov, Kazbek; Ali, Mohd Rodzi; Zhumadilova, Anara; Toyoda, Shin; Endo, Satoru; Tanaka, Kenichi; Okamoto, Tetsuji; Hoshi, Masaharu

    2009-11-01

    The method of electron spin resonance (ESR) dosimetry has been applied to human tooth enamel, to obtain individual absorbed doses of residents of settlements in vicinity of Ust-Kamenogorsk city, Kazakhstan (located about 400 km to the east from the epicenter of explosion at the Semipalatinsk Nuclear Test Site, SNTS). This region developed as a major mining and metallurgical center during the Soviet period (uranium production). Most of the investigated settlements (Ust-Kamenogorsk city, Glubokoe, Tavriya, Gagarino) are located near the central axis of the radioactive fallout trace that originated from the surface nuclear test on 24 August 1956, while the Kokpekty settlement (located 400 km to the Southeast from SNTS) was chosen as a control because it was not subjected to any radioactive contamination. In total, 44 samples were measured. It was found that the excess doses obtained after subtraction of natural background radiation ranged up to about 114 mGy for residents of Ust-Kamenogorsk city, whose tooth enamel was formed before 1956. For residents of Gagarino, excess doses did not exceed 47 mGy for all ages. For residents of Tavriya, the maximum excess dose was 54 mGy, while for residents of Glubokoe it was about 58 mGy. For the population of the Shemonaikha settlements located at a distance of about 70 km from the central axis of the radioactive fallout trace, highest excess doses were 110 mGy. These high doses may be due to the influence of uranium enterprises located in that region, but probably not due to dental X-ray irradiation. For a final conclusion on the radiological situation in this region, the number of samples was too small and, therefore, more work is required to obtain representative results.

  20. Evaluation of detectors for blood bioanalysis in Lu-177 and I-131 therapies for bone marrow dosimetry

    International Nuclear Information System (INIS)

    Degenhardt, Amilie Louize

    2016-01-01

    The measures traceability is mandatory for minimizing uncertainties in internal dosimetry for radiopharmaceuticals clinical studies and ensures the quality of the standard. Equipment should have resolution and efficiency compatible with radionuclides energies and, additionally, be able to quantify variations in human bodies' activities samples since the initial administration near the minimum residual activities. For testing three equipment (ionization chamber Capintec 25R, sodium iodine scintillator LTI Genesys Gamma-1 and high hyperpure germanium detector Canberra), they were prepared Lu-177 and I-131 radiation sources simulating patient's blood samples activities by adopting the following hypothesis: (1) initial activities according the Brazilian protocols; (2) blood volume in the whole body (5.3 L for adult men and 1.4 L for 5 years-old children); (3) effective half-lives (1.61 h and 42.9 h for Lu-177 bi-exponential adjustment and 15.7 h for I-131 mono-exponential adjustment); (4) sampling between 30 min and 168 h; (v) blood density adjustments. The standard sources were measured in the secondary standard ionization chamber Centronics IG11 at the Laboratorio Nacional de Metrologia das Radiacoes Ionizantes. The Capintec ionization chamber efficiencies ranged, respectively for I-131 and Lu-177, between (111.58±0.02)% and (102.27±0.01)% and HPGe semiconductor detector efficiencies ranged, respectively, between (89.40±0.03)% and (87.80±0.04)%. For the NaI detector, when the Lu-177 sources were positioned inside the detector the efficiencies ranged between (12.66±0.01)% and (11.54± 0.07)% and when the sources were positioned at 5 cm and 10 cm from the detector the efficiencies decreased to less than 5%. For I-131 sources positioned inside the detector, the efficiencies ranged between (29.76±0.21)% and (30.20±0.04)% and they decreased to less than 5% when they were positioned at 5 cm and 10 cm from the detector (deviation greater than 95

  1. The personal dosimetry in Mexico

    International Nuclear Information System (INIS)

    Salazar, M.A.

    2006-01-01

    The Personal Dosimetry in Mexico, has an approximately 30 year-old history; and it had been and it is at the moment, one of the more important resources with which the personnel that works with ionizing radiation sources counts for its protection. The Personal Dosimetry begins with the film dosimetry, technique that even continues being used at the present time by some users, and the main reason of its use is for economic reasons. At the moment this technique, it has been surpassed, by the Thermoluminescent dosimetry, which has taken a lot of peak, mainly by the technological development with which it is counted at the present time; what has given as a result that this technique becomes tip technology; that supported in the characteristic of the used materials, as the handling and processing of the information associated with the new PC, digitizer cards, software etc, what has allowed increases it potential. In this work the current necessities of the market are presented as well as an analysis of the future real necessities in Mexico, at national level, the companies that provide this service and that they spread to satisfy this necessity of the market, including the different used technologies are also mentioned. The application ranges, at the same time, of the advantages and disadvantages of the different systems of Personal Dosimetry in the market. The companies that at the moment provide the service of Personal Dosimetry, its use materials and equipment in indistinct form, for the monitoring of gamma radiation, beta particles, different qualities of x-ray radiation, and sometimes neutrons. The monitoring of the exposed personnel at the diverse sources of ionizing radiation mentioned is carried out in many occasions without having with the materials (detectors), neither the appropriate infrastructure and therefore without the quality control that guarantees a correct evaluation of the dose equivalent, as a result of the exposure to the ionizing radiations; it

  2. Cost-effective pediatric head and body phantoms for computed tomography dosimetry and its evaluation using pencil ion chamber and CT dose profiler

    Directory of Open Access Journals (Sweden)

    A Saravanakumar

    2015-01-01

    Full Text Available In the present work, a pediatric head and body phantom was fabricated using polymethyl methacrylate (PMMA at a low cost when compared to commercially available phantoms for the purpose of computed tomography (CT dosimetry. The dimensions of head and body phantoms were 10 cm diameter, 15 cm length and 16 cm diameter, 15 cm length, respectively. The dose from a 128-slice CT machine received by the head and body phantom at the center and periphery were measured using a 100 mm pencil ion chamber and 150 mm CT dose profiler (CTDP. Using these values, the weighted computed tomography dose index (CTDIw and in turn the volumetric CTDI (CTDIv were calculated for various combinations of tube voltage and current-time product. A similar study was carried out using standard calibrated phantom and the results have been compared with the fabricated ones to ascertain that the performance of the latter is equivalent to that of the former. Finally, CTDIv measured using fabricated and standard phantoms were compared with respective values displayed on the console. The difference between the values was well within the limits specified by Atomic Energy Regulatory Board (AERB, India. These results indicate that the cost-effective pediatric phantom can be employed for CT dosimetry.

  3. SU-F-T-395: Evaluation of Best Dosimetry Achievable with VMAT and IMRT Treatment Techniques Targeting Borderline Resectable Pancreatic Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Harpool, K; Schnell, E; Herman, T; Ahmad, S; De La Fuente Herman, T [University of Oklahoma Health Sciences Center, Oklahoma City, OK (United States)

    2016-06-15

    Purpose: To determine from retrospective study the most appropriate technique for targeting small borderline operable pancreatic cancer surrounding blood vessels by evaluating the dosimetry and normal tissue sparing achievable using Volumetric Modulated Arc Therapy (VMAT) and Intensity Modulated Radiation Therapy (IMRT). Methods: Treatment plans from ten patients who have undergone treatment with a prescribed dose of 4950 cGy, at 275 cGy per fraction, were analyzed. All plans were replanned using Eclipse TPS (Varian Medical Systems, Palo Alto, CA) with complementary VMAT or IMRT techniques to obtain paired data sets for comparison. The coverage to at least 95% of the planned target volume (PTV) was normalized to receive 100% of the prescription dose. The normal tissue constraints followed the quantitative analysis of normal tissue effects in the clinic (QUANTEC) guidelines and the organs at risks (OARs) were liver, kidneys, spinal cord and bowel. The plan evaluation was based on conformity index (CI), homogeneity index (HI), uniformity index (UI), DVH parameters, and student’s-t statistics (2 tails). Results: The VMAT technique delivered less maximum dose to the right kidney, left kidney, total kidney, liver, spinal cord, and bowel by 9.3%, 5.9%, 6.7%, 3.9%, 15.1%, 3.9%, and 4.3%, respectively. The averaged V15 for the total kidney was 10.21% for IMRT and 7.29% for VMAT. The averaged V20 for the bowel was 19.89% for IMRT and 14.06% for VMAT. On average, the CI for IMRT was 1.20 and 1.16 for VMAT (p = 0.20). The HI was 0.08 for both techniques (p = 0.91) and UI was 1.05 and 1.06 for IMRT and VMAT respectively (p = 0.59). Conclusion: Both techniques achieve adequate PTV coverage. Although VMAT techniques show better normal tissue sparing from excessive dose, no significant differences were observed. Slight discrepancies may rise from different versions of calculation algorithms.

  4. Pilot study: relative dose of the TLD, OSL and Radiochromic film applied in CT exams dosimetry

    International Nuclear Information System (INIS)

    Kikuti, C.F.; Maia, R.S.I.; Romano, R.F.T.; Daros, K. A.C.

    2015-01-01

    At DDI/UNIFESP, the abdomen and chest CT exams correspond to 38% of the exams, becoming the focus of studies. The aim of this study is to assess the relative dose using TLDs, OSLs and RF for the evaluation of the dose distribution in the skin in abdomen CT exams. The simulation of the CT exam was performed in an anthropomorphic phantom, using a CT scanner Philips, Brilliance/64 and TLDs, OSLs and RF fixed along the sagittal axis of the phantom. The OSLs showed similar performance to the TLDs and RF shows low accuracy, resulting in an average value (0.927±0.022). (author)

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

    International Nuclear Information System (INIS)

    Haskell, E.H.; Kenner, G.H.; Hayes, R.B.

    1996-01-01

    Electron paramagnetic resonance spectroscopy (EPR) of tooth enamel is a relatively new technique for retrospective dosimetry that in the past two years has seen increasing effort towards its development and evaluation. Efforts have centered on determining the accuracy which may be achieved with current measurement techniques as well as the minimum doses detectable. The study was focused on evaluating some factors which influence the accuracy of EPR dosimetry of enamel. Reported are studies on sample intercomparisions, instrumental considerations, and effects of dental x-rays, environmental sunlight and ultraviolet radiation

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

    Energy Technology Data Exchange (ETDEWEB)

    Haskell, E.H.; Kenner, G.H.; Hayes, R.B. [Utah Univ., Salt Lake City, UT (United States). Center for Applied Dosimetry; Chumak, V.; Shalom, S. [All-Union Scientific Centre of Radiation Medicine, Kiev (Ukraine)

    1996-01-01

    Electron paramagnetic resonance spectroscopy (EPR) of tooth enamel is a relatively new technique for retrospective dosimetry that in the past two years has seen increasing effort towards its development and evaluation. Efforts have centered on determining the accuracy which may be achieved with current measurement techniques as well as the minimum doses detectable. The study was focused on evaluating some factors which influence the accuracy of EPR dosimetry of enamel. Reported are studies on sample intercomparisions, instrumental considerations, and effects of dental x-rays, environmental sunlight and ultraviolet radiation.

  7. SU-E-T-507: Internal Dosimetry in Nuclear Medicine Using GATE and XCAT Phantom: A Simulation Study

    Energy Technology Data Exchange (ETDEWEB)

    Fallahpoor, M; Abbasi, M [Tehran University of Medical Sciences, Vali-Asr Hospital, Tehran, Tehran (Iran, Islamic Republic of); Sen, A [University of Houston, Houston, TX (United States); Parach, A [Shahid Sadoughi University of Medical Sciences, Yazd, Yazd (Iran, Islamic Republic of); Kalantari, F [UT Southwestern Medical Center, Dallas, TX (United States)

    2015-06-15

    Purpose Monte Carlo simulations are routinely used for internal dosimetry studies. These studies are conducted with humanoid phantoms such as the XCAT phantom. In this abstract we present the absorbed doses for various pairs of source and target organs using three common radiotracers in nuclear medicine. Methods The GATE software package is used for the Monte Carlo simulations. A typical female XCAT phantom is used as the input. Three radiotracers 153Sm, 131I and 99mTc are studied. The Specific Absorbed Fraction (SAF) for gamma rays (99mTc, 153Sm and 131I) and Specific Fraction (SF) for beta particles (153Sm and 131I) are calculated for all 100 pairs of source target organs including brain, liver, lung, pancreas, kidney, adrenal, spleen, rib bone, bladder and ovaries. Results The source organs themselves gain the highest absorbed dose as compared to other organs. The dose is found to be inversely proportional to distance from the source organ. In SAF results of 153Sm, when the source organ is lung, the rib bone, gain 0.0730 (Kg-1) that is more than lung itself. Conclusion The absorbed dose for various organs was studied in terms of SAF and SF. Such studies hold importance for future therapeutic procedures and optimization of induced radiotracer.

  8. Status of neutron cross sections for reactor dosimetry

    International Nuclear Information System (INIS)

    Vlasov, M.F.; Fabry, A.; McElroy, W.N.

    1977-03-01

    The status of current international efforts to develop standardized sets of evaluated energy-dependent (differential) neutron cross sections for reactor dosimetry is reviewed. The status and availability of differential data are considered, some recent results of the data testing of the ENDF/B-IV dosimetry file using 252 Cf and 235 U benchmark reference neutron fields are presented, and a brief review is given of the current efforts to characterize and identify dosimetry benchmark radiation fields

  9. On multichannel film dosimetry with channel-independent perturbations

    International Nuclear Information System (INIS)

    Méndez, I.; Peterlin, P.; Hudej, R.; Strojnik, A.; Casar, B.

    2014-01-01

    Purpose: Different multichannel methods for film dosimetry have been proposed in the literature. Two of them are the weighted mean method and the method put forth byMicke et al. [“Multichannel film dosimetry with nonuniformity correction,” Med. Phys. 38, 2523–2534 (2011)] and Mayer et al. [“Enhanced dosimetry procedures and assessment for EBT2 radiochromic film,” Med. Phys. 39, 2147–2155 (2012)]. The purpose of this work was to compare their results and to develop a generalized channel-independent perturbations framework in which both methods enter as special cases. Methods: Four models of channel-independent perturbations were compared: weighted mean, Micke–Mayer method, uniform distribution, and truncated normal distribution. A closed-form formula to calculate film doses and the associated type B uncertainty for all four models was deduced. To evaluate the models, film dose distributions were compared with planned and measured dose distributions. At the same time, several elements of the dosimetry process were compared: film type EBT2 versus EBT3, different waiting-time windows, reflection mode versus transmission mode scanning, and planned versus measured dose distribution for film calibration and for γ-index analysis. The methods and the models described in this study are publicly accessible through IRISEU. Alpha 1.1 ( http://www.iriseu.com ). IRISEU. is a cloud computing web application for calibration and dosimetry of radiochromic films. Results: The truncated normal distribution model provided the best agreement between film and reference doses, both for calibration and γ-index verification, and proved itself superior to both the weighted mean model, which neglects correlations between the channels, and the Micke–Mayer model, whose accuracy depends on the properties of the sensitometric curves. With respect to the selection of dosimetry protocol, no significant differences were found between transmission and reflection mode scanning

  10. On multichannel film dosimetry with channel-independent perturbations.

    Science.gov (United States)

    Méndez, I; Peterlin, P; Hudej, R; Strojnik, A; Casar, B

    2014-01-01

    Different multichannel methods for film dosimetry have been proposed in the literature. Two of them are the weighted mean method and the method put forth by Micke et al. ["Multichannel film dosimetry with nonuniformity correction," Med. Phys. 38, 2523-2534 (2011)] and Mayer et al. ["Enhanced dosimetry procedures and assessment for EBT2 radiochromic film," Med. Phys. 39, 2147-2155 (2012)]. The purpose of this work was to compare their results and to develop a generalized channel-independent perturbations framework in which both methods enter as special cases. Four models of channel-independent perturbations were compared: weighted mean, Micke-Mayer method, uniform distribution, and truncated normal distribution. A closed-form formula to calculate film doses and the associated type B uncertainty for all four models was deduced. To evaluate the models, film dose distributions were compared with planned and measured dose distributions. At the same time, several elements of the dosimetry process were compared: film type EBT2 versus EBT3, different waiting-time windows, reflection mode versus transmission mode scanning, and planned versus measured dose distribution for film calibration and for γ-index analysis. The methods and the models described in this study are publicly accessible through IRISEU. Alpha 1.1 (http://www.iriseu.com). IRISEU. is a cloud computing web application for calibration and dosimetry of radiochromic films. The truncated normal distribution model provided the best agreement between film and reference doses, both for calibration and γ-index verification, and proved itself superior to both the weighted mean model, which neglects correlations between the channels, and the Micke-Mayer model, whose accuracy depends on the properties of the sensitometric curves. With respect to the selection of dosimetry protocol, no significant differences were found between transmission and reflection mode scanning, between 75 ± 5 min and 20 ± 1 h waiting

  11. Optimization of the preparation method of LiF: Mg, Cu, P and study of its thermoluminescent properties to be used in ionizing radiation dosimetry

    International Nuclear Information System (INIS)

    Gonzalez M, P.R.

    1995-01-01

    In this thesis the preparation and dosimetric properties of the thermoluminescence phosphor LiF doped with magnesium, copper and phosphorus are studied. In chapter 1 luminescence phenomenon in solids is described, emphasizing the importance of thermally stimulated luminescence known as thermoluminescence (TL) as well as its application in ionizing radiation dosimetry. The models used to determine the kinetics parameters in the TL phenomenon are described in chapter 2. In chapter 3, the dosimetric characteristics of a TL materials and its requirements for dosimetry are analyzed. The preparation method of LiF: Mg, Cu, P is presented in chapter 4 studying its general characteristics for dosimetry. The concentrations of dopants, glow curve structure, TL response to gamma, beta and alpha exposures are studied along with those of LiF: Mg, Cu, P prepared for other authors and with those of LiF: Mg, Ti (TLD-100). The kinetic parameters of the phosphor were determined by the deconvolution method. Pellets of this new phosphor powder were made by pressing it at room temperature and sintering in inert atmosphere at 700 Centigrade degrees. Dosimetric characteristics of these pellets were also studied. Chapter 5 presents the results and conclusions of this study. The new dosimeter exhibited three peaks in its glow curve at 140, 180 and 220 Centigrade degrees respectively. Its TL response to gamma radiation was linear from 43.5 μ Gy to 100 Gy. This dosimeter is reusable and stable without significant loss of sensitivity. Its sensitivity was about 30 times higher than that of TLD-100. Fading of this dosimeter was negligible at room temperature as well as at body temperature (37 Centigrade degrees), and 65% at 60 Centigrade degrees. In conclusion, this dosimeter meets all the requirements of the ANSI standard. These and other characteristics render this dosimeter useful in diverse applications of radiation dosimetry. (Author)

  12. Considerations on the miniaturization of detectors for in vivo dosimetry in radiotherapy: A Monte Carlo study

    Energy Technology Data Exchange (ETDEWEB)

    Cunha, Micaela; Testa, Etienne [Université de Lyon, F-69622, Lyon (France); CNRS/IN2P3, Institut de Physique Nucléaire de Lyon (France); Beuve, Michael, E-mail: m.beuve@ipnl.in2p3.fr [Université de Lyon, F-69622, Lyon (France); CNRS/IN2P3, Institut de Physique Nucléaire de Lyon (France); Balosso, Jacques; Chaikh, Abdulhamid [Department of Radiation Oncology and Medical Physics, Grenoble Alpes University Hospital (CHUGA), Grenoble (France)

    2017-05-15

    The evolution of technology in radiotherapy nowadays allows us to deliver much higher doses to the target volumes, thanks to better absorbed dose distribution accuracy and conformation, while better sparing healthy tissues. In photon radiotherapy, higher precision usually entails employing small and moving beams. This emphasizes the role of in vivo dosimetry, which assesses internal absorbed dose rather than entrance dose. This, along with advances in materials science, results in a tendency towards the miniaturization of dosimeters. However, the stochastic nature of the radiation-matter interaction takes on greater importance at smaller scales, resulting in fluctuations in energy deposition whose effect may not be negligible. Miniaturization needs to take this into account. We estimated such fluctuations by Monte Carlo simulations considering energy deposition in cylindrical volumes of different sizes and for several absorbed dose values. We not only present and discuss the probability distributions of absorbed doses for a large range of target sizes (0.1–10 μm) and clinically relevant doses (0.1–10 Gy), but also derive an estimation of the risk of measuring an absorbed dose with a value outside a given interval of tolerance (3, 5 and 10%) around the expected dose. The distributions presented features consistent with the theory of microdosimetry. Those for dosimeter sizes smaller than 0.3 μm showed a very high dispersion in specific energy, while those for 10 μm dosimeters tended to become Gaussian and narrower with increasing absorbed dose. The probability of measuring an absorbed dose outside the defined interval of tolerance is close to 100% for the smallest size, regardless of the dose and the interval width considered. It decreases with increasing dose, dosimeter size and width of the interval of tolerance. The best results were obtained with 10 μm dosimeters, for which the probability of doses outside the tolerance range is always zero for absorbed

  13. Characterization and optimization of the RA-3 experimental dosimetry for normal sheep lung radio-tolerance study

    International Nuclear Information System (INIS)

    Soto, M.S.; Gonzalez, S.J.; Thorp, Silvia I.; Pozzi, Emiliano; Gadan, M.; Miller, Marcelo; Farias, R.

    2009-01-01

    In the spirit of the novel technique proposed by the University of Pavia group (Italy) to irradiate an isolated organ using BNCT, the Comision Nacional de Energia Atomica (CNEA) in collaboration with the Fundacion Favaloro has initiated a project that aims to investigate the feasibility of BNCT for ex-situ treatment of diffuse metastatic disease in the lungs. The present work was carried out in the framework of the undergoing experimental study of the radio tolerance of normal sheep lung. With the purpose of characterizing and optimizing the resulting experimental dosimetry in normal lung subjected to neutron irradiation in the BNCT facility of the RA-3 reactor (CNEA), we have performed a series of experiments to find the optimum configuration of the container-lung system deriving a dose distribution preferentially uniform throughout the organ. Once the optimal set-up was established, we measured the total gamma dose rate and estimated the irradiation time compatible with the maximum tolerable dose of normal lung resulting from previous studies in rats. This estimation was performed using RBE, CBE and tolerance dose values derived from radiobiological studies with BNCT. In parallel with the experimental characterization, we built two different computational models of the container-lung system to perform Monte Carlo simulation with MCNP and Treatment Planning System NCTPlan. (author)

  14. Evaluation of 3D printing materials for fabrication of a novel multi-functional 3D thyroid phantom for medical dosimetry and image quality

    Science.gov (United States)

    Alssabbagh, Moayyad; Tajuddin, Abd Aziz; Abdulmanap, Mahayuddin; Zainon, Rafidah

    2017-06-01

    Recently, the three-dimensional printer has started to be utilized strongly in medical industries. In the human body, many parts or organs can be printed from 3D images to meet accurate organ geometries. In this study, five common 3D printing materials were evaluated in terms of their elementary composition and the mass attenuation coefficients. The online version of XCOM photon cross-section database was used to obtain the attenuation values of each material. The results were compared with the attenuation values of the thyroid listed in the International Commission on Radiation Units and Measurements - ICRU 44. Two original thyroid models (hollow-inside and solid-inside) were designed from scratch to be used in nuclear medicine, diagnostic radiology and radiotherapy for dosimetry and image quality purposes. Both designs have three holes for installation of radiation dosimeters. The hollow-inside model has more two holes in the top for injection the radioactive materials. The attenuation properties of the Polylactic Acid (PLA) material showed a very good match with the thyroid tissue, which it was selected to 3D print the phantom using open source RepRap, Prusa i3 3D printer. The scintigraphy images show that the phantom simulates a real healthy thyroid gland and thus it can be used for image quality purposes. The measured CT numbers of the PA material after the 3D printing show a close match with the human thyroid CT numbers. Furthermore, the phantom shows a good accommodation of the TLD dosimeters inside the holes. The 3D fabricated thyroid phantom simulates the real shape of the human thyroid gland with a changeable geometrical shape-size feature to fit different age groups. By using 3D printing technology, the time required to fabricate the 3D phantom was considerably shortened compared to the longer conventional methods, where it took only 30 min to print out the model. The 3D printing material used in this study is commercially available and cost

  15. Radiochromic film dosimetry

    International Nuclear Information System (INIS)

    Xu Zhiyong

    2002-01-01

    Radiochromic film dosimetry was developed to measure ionization irradiation dose for industry and medicine. At this time, there are no comprehensive guideline on the medical application, calibration method and densitometer system for medicine. The review gives update on Radiochromic film dosimetry used for medicine, including principles, film model and material, characteristics, calibration method, scanning densitometer system and medical application

  16. Personal dosimetry in Kazakhstan

    International Nuclear Information System (INIS)

    Khvoshnyanskaya, I.R.; Vdovichenko, V.G.; Lozbin, A.Yu.

    2003-01-01

    KATEP-AE Radiation Laboratory is the first organization in Kazakhstan officially licensed by the Kazakhstan Atomic Energy Committee to provide individual dosimetry services. The Laboratory was established according to the international standards. Nowadays it is the largest company providing personal dosimetry services in the Republic of Kazakhstan. (author)

  17. Proceedings of the 5. symposium on neutron dosimetry. Beam dosimetry

    International Nuclear Information System (INIS)

    Schraube, H.; Burger, G.; Booz, J.

    1985-01-01

    Proceedings of the fifth symposium on neutron dosimetry, organized at Neuherberg, 17-21 September 1984, by the Commission of the European Communities and the GSF Neuherberg, with the co-sponsorship of the US Department of Energy, Office of Health and Environmental Research. The proceedings deal with research on concepts, instruments and methods in radiological protection for neutrons and mixed neutron-gamma fields, including the generation, collection and evaluation of new dosimetric data, the derivation of relevant radiation protection quantitites, and the harmonization of experimental methods and instrumentation by intercomparison programmes. Besides radiation protection monitoring, the proceedings also report on the improvement of neutron beam dosimetry in the fields of radiobiology and radiation therapy

  18. Dosimetry for radiation processing

    International Nuclear Information System (INIS)

    McLaughlin, W.L.; Boyd, A.W.; Chadwick, K.H.; McDonald, J.C.; Miller, A.

    1989-01-01

    Radiation processing is a relatively young industry with broad applications and considerable commercial success. Dosimetry provides an independent and effective way of developing and controlling many industrial processes. In the sterilization of medical devices and in food irradiation, where the radiation treatment impacts directly on public health, the measurements of dose provide the official means of regulating and approving its use. In this respect, dosimetry provides the operator with a means of characterizing the facility, of proving that products are treated within acceptable dose limits and of controlling the routine operation. This book presents an up-to-date review of the theory, data and measurement techniques for radiation processing dosimetry in a practical and useful way. It is hoped that this book will lead to improved measurement procedures, more accurate and precise dosimetry and a greater appreciation of the necessity of dosimetry for radiation processing. (author)

  19. Radio-analysis. Applications: biological dosimetry; Radioanalyse. Applications: dosage biologique

    Energy Technology Data Exchange (ETDEWEB)

    Bourrel, F. [CEA Saclay, INSTN, Institut National des Sciences et Techniques Nucleaires, 91 - Gif-sur-Yvette (France); Courriere, Ph. [UFR de Pharmacie, 31 - Toulouse (France)

    2003-06-01

    Radioisotopes have revolutionized the medical biology. Radio-immunology remains the reference measurement of the infinitely small in biology. Constant efforts have been performed to improve the simpleness, detectability and fastness of the method thanks to an increasing automation. This paper presents: 1 - the advantages of compounds labelling and the isotopic dilution; 2 - the antigen-antibody system: properties, determination of the affinity constant using the Scatchard method; 3 - radio-immunologic dosimetry: competitive dosimetry (radioimmunoassay), calibration curve and mathematical data processing, application to the free thyroxine dosimetry, immunoradiometric dosimetry (immunoradiometric assay), evaluation of the analytical efficiency of a radioimmunoassay; 4 - detection of the radioactive signal (solid and liquid scintillation). (J.S.)

  20. Update of the evaluation of the cross section of the neutron dosimetry reaction 103Rh(n,n')103mRh

    International Nuclear Information System (INIS)

    Pavlik, A.; Miah, M.M.H.; Strohmaier, B.; Vonach, H.

    1995-10-01

    On the occasion of a new measurement of the excitation function of the reaction 103 Rh(n,n') 103m Rh in the energy range between 5.69 and 12.0 MeV performed at the present institute in collaboration wit the PTB Braunschweig, the cross section of this reaction, which is part of the International Reactor Dosimetry Field (IRDF-90), was re-evaluated. Whereas the energy range of the evaluation, namely from threshold to 20 MeV, was kept unchanged with respect to IRDF-90, the underlying data base was extended by the experiment mentioned as well as by another measurement, and revised with regard to judgement and normalization of older data in the light of recent information. Based on the experimental data upgraded in this way, new model calculations were carried out, which in the energy region 14 - 20 MeV served to supplement the experimental cross sections for this evaluation. The cross sections and their uncertainties were evaluated in energy groups with widths of 0.2 to 1.0 MeV, and the relative correlation matrix of the evaluated cross sections at the different energies was calculated. The results presented here supersede the corresponding values published in Physics Data 13-5 and included to the IRDF-90. (author). 26 refs, 4 figs, 6 tabs

  1. Exposure Setup and Dosimetry for a Study on Effects of Mobile Communication Signals on Human Hematopoietic Stem Cells in vitro

    Science.gov (United States)

    Rohland, Martina; Baaske, Kai; Gläser, Katharina; Hintzsche, Henning; Stopper, Helga; Kleine-Ostmann, Thomas; Schrader, Thorsten

    2017-09-01

    In this paper we describe the design of an exposure setup used to study possible non-thermal effects due to the exposure of human hematopoietic stem cells to GSM, UMTS and LTE mobile communication signals. The experiments are performed under fully blinded conditions in a TEM waveguide located inside an incubator to achieve defined environmental conditions as required for the living cells. Chamber slides containing the cells in culture medium are placed on the septum of the waveguide. The environmental and exposure parameters such as signal power, temperatures, relative humidity and CO2 content of the surrounding atmosphere are monitored permanently during the exposure experiment. The power of the exposure signals required to achieve specific absorption rates of 0.5, 1, 2 and 4 W kg-1 are determined by numerical calculation of the field distribution inside the cell culture medium at 900 MHz (GSM), 1950 MHz (UMTS) and 2535 MHz (LTE). The dosimetry is verified both with scattering parameter measurements on the waveguide with and without containers filled with cell culture medium and with temperature measurements with non-metallic probes in separate heating experiments.

  2. Exposure Setup and Dosimetry for a Study on Effects of Mobile Communication Signals on Human Hematopoietic Stem Cells in vitro

    Directory of Open Access Journals (Sweden)

    M. Rohland

    2017-09-01

    Full Text Available In this paper we describe the design of an exposure setup used to study possible non-thermal effects due to the exposure of human hematopoietic stem cells to GSM, UMTS and LTE mobile communication signals. The experiments are performed under fully blinded conditions in a TEM waveguide located inside an incubator to achieve defined environmental conditions as required for the living cells. Chamber slides containing the cells in culture medium are placed on the septum of the waveguide. The environmental and exposure parameters such as signal power, temperatures, relative humidity and CO2 content of the surrounding atmosphere are monitored permanently during the exposure experiment. The power of the exposure signals required to achieve specific absorption rates of 0.5, 1, 2 and 4 W kg−1 are determined by numerical calculation of the field distribution inside the cell culture medium at 900 MHz (GSM, 1950 MHz (UMTS and 2535 MHz (LTE. The dosimetry is verified both with scattering parameter measurements on the waveguide with and without containers filled with cell culture medium and with temperature measurements with non-metallic probes in separate heating experiments.

  3. Safety, pharmacokinetic and dosimetry evaluation of the proposed thrombus imaging agent {sup 99m}Tc-DI-DD-3B6/22-80B3 Fab'

    Energy Technology Data Exchange (ETDEWEB)

    Macfarlane, David J. [Royal Brisbane and Women' s Hospital, Department of Nuclear Medicine, Brisbane (Australia); Smart, Richard C. [St George Hospital, Department of Nuclear Medicine, Sydney (Australia); Tsui, Wendy W. [St George Hospital, Department of Nuclear Medicine, Sydney (Australia); University of New South Wales, School of Medicine, Sydney (Australia); Gerometta, Michael [AGEN Biomedical Limited, Research and Development, Brisbane (Australia); Eisenberg, Paul R. [Eli Lilly Company, Lilly Research Laboratories, Indianapolis (United States); Scott, Andrew M. [Austin Health, Centre for PET, Melbourne (Australia); Ludwig Institute for Cancer Research, Melbourne (Australia)

    2006-06-15

    {sup 99m}Tc-DI-DD-3B6/22-80B3 (Thromboview, hereafter abbreviated to {sup 99m}Tc-DI-80B3 Fab') is a humanised, radiolabelled monoclonal antibody Fab' fragment with high affinity and specificity for the D-dimer domain of cross-linked fibrin. The purpose of this study was to evaluate the safety, pharmacokinetics and dosimetry of four increasing doses of {sup 99m}Tc-DI-80B3 Fab' in healthy volunteers. Thirty-two healthy volunteers (18-70 years; 16 male, 16 female) received a single intravenous injection of 0.5, 1.0, 2.0 or 4.0 mg of {sup 99m}Tc-DI-80B3 Fab'. Safety outcomes (vital signs, electrocardiography, haematology, biochemistry, adverse events and development of human anti-human antibodies) were assessed up to 30 days post injection. Blood and urine samples were collected up to 48 h post injection. Gamma camera images were acquired at 0.5, 1, 2, 4, 6 and 24 h post injection. Dosimetry was performed using standard MIRD methodology. No adverse events considered to be drug related were observed. Human anti-human antibody was not detectable in any subject during the follow-up period. {sup 99m}Tc-DI-80B3 Fab' had a rapid initial plasma clearance (t{sub 1/2}{alpha}=1 h). The pharmacokinetic profile of the Fab' fragment was generally linear across the four dose cohorts. By 24 h, 30-35% of the administered radioactivity appeared in the urine. There was marked renal accumulation with time, but no specific uptake was identified within other normal tissues. The effective dose was 9 mSv/750 MBq. (orig.)

  4. Validation and dosimetric evaluation employing the techniques of TL and OSL of thermoluminescent materials for application in the dosimetry of clinical beams of electrons used in total irradiation of the skin - TSI

    International Nuclear Information System (INIS)

    Almeida, Shirlane Barbosa de

    2017-01-01

    In vivo dosimetry has become an important role for the treatment of total skin irradiation within a rigorous quality assurance program that should be an integral part of the radiotherapy departments. TSI dosimetry is difficult because of the complexity of the treatment in assessing dose uniformity and measuring the dose absorbed at shallow depths throughout the skin surface extent, resulting in a wide variation in dose distribution. The TLDs have proven to be very useful for the distribution and verification of the dose prescribed for the patient as the dose may differ from place to place due to patient body geometry, overlapping of structures and asymmetries of the radiation field. The use of TLDs in vivo can identify variations in the prescribed dose because its measurement accuracy and great precision. Several types of dosimeters have been used in the radiotherapy sectors, the most commonly used are Lithium Fluride (TLD-100), where it obtains a long history in this type of application. New dosimetric materials have gained great importance in the dosimetry of clinical electron beams, such as Dysprosium-doped Calcium Sulphate (TL) and Carbon doped (OSL) based Aluminum Oxide, This work evaluates the performance of the respective thermoluminescent dosimeters and the optically stimulated luminescence in the dosimetry of clinical electron beams used in total irradiation of the skin. (author)

  5. Dosimetric evaluation of thermoluminescent LiF:Mg,Ti and CaSO4 :Dy dosimeters and LiF microdosimeters for application in in vivo dosimetry of clinical electron beams

    International Nuclear Information System (INIS)

    Bravim, Amanda; Campos, Leticia L.

    2009-01-01

    The verification of the patient dose has been recommended to improve the quality of radiotherapy treatment by various organizations such as AAPM (American Association of Physicists in Medicine) and ESTRO (European Society of Therapeutic Radiology and Oncology). The in vivo dosimetry has become an important part in the program of quality assurance (QA) in the departments of radiotherapy and has proved very useful in determining the dose applied to a particular patient, as well as detection of various types of errors in the dose process application. Thermoluminescent dosimeters (TLD) play an important role in radiation dosimetry and present advantages that make them useful for in vivo dosimetry in patients. This paper aims to evaluate the performance of LiF microdosimeters and LiF: Mg,Ti and CaSO 4 : Dy dosimeters in 60 Co gamma field and select the detectors groups which present TL response with sensitivity and reproducibility better than ± 5%. It is expected a standardized method of employing the thermoluminescent dosimetry technique and development of a dosimetric system in accordance with the international recommendations. (author)

  6. A Monte Carlo dosimetry study using Henschke applicator for cervical brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Pei-Chieh [Department of Biomedical Engineering and Environmental Sciences, National Tsing Hua University, 101 Sec. 2, Kung Fu Road, Hsinchu 30013, Taiwan (China); Department of Radiation Oncology, Cathay General Hospital, 280 Renai Rd. Sec.4, Taipei 106, Taiwan (China); Chao, Tsi-Chian [Department of Medical Imaging and Radiological Science, Chang Gung University, 259 Wen-Hwa 1st Road, Kwei-Shan, Tao-Yuan 333, Taiwan (China); Lee, Chung-Chi [Department of Medical Imaging and Radiological Science, Chang Gung University, 259 Wen-Hwa 1st Road, Kwei-Shan, Tao-Yuan 333, Taiwan (China); Department of Radiation Oncology, Chang Gung Memorial Hospital, 5 Fu-Hsin Street, Kwei-Shan, Tao-Yuan 333, Taiwan (China); Wu, Ching-Jung [Department of Radiation Oncology, Cathay General Hospital, 280 Renai Rd. Sec.4, Taipei 106, Taiwan (China); Tung, Chuan-Jong, E-mail: cjtung@mail.cgu.edu.t [Department of Medical Imaging and Radiological Science, Chang Gung University, 259 Wen-Hwa 1st Road, Kwei-Shan, Tao-Yuan 333, Taiwan (China)

    2010-07-21

    In recent years the Henschke applicator has been widely used for gynecologic patients treated by brachytherapy in Taiwan. However, the commercial brachytherapy planning system did not properly evaluate the dose perturbation caused by the Henschke applicator. Since the European Society for Therapeutic Radiology and Oncology advised that the effect of source shielding should be incorporated into the brachytherapy planning system, it required calculation and comparison of the dose distribution around the applicator. This study used the Monte Carlo MCNP code to simulate the dose distribution in a water phantom that contained the Henschke applicator with one tandem and two ovoids. Three dwell positions of a high dose rate {sup 192}Ir source were simulated by including and excluding the applicator. The mesh tally option of the MCNP was applied to facilitate the calculation of a large number of tallies in the phantom. The voxel size effect and the charge particle equilibrium were studied by comparing the results calculated with different tally options. The calculated results showed that the brachytherapy planning system overestimated the rectal dose and that the shielding material in the applicator contributed more than 40% to the rectal dose.

  7. A Monte Carlo dosimetry study using Henschke applicator for cervical brachytherapy

    International Nuclear Information System (INIS)

    Yu, Pei-Chieh; Chao, Tsi-Chian; Lee, Chung-Chi; Wu, Ching-Jung; Tung, Chuan-Jong

    2010-01-01

    In recent years the Henschke applicator has been widely used for gynecologic patients treated by brachytherapy in Taiwan. However, the commercial brachytherapy planning system did not properly evaluate the dose perturbation caused by the Henschke applicator. Since the European Society for Therapeutic Radiology and Oncology advised that the effect of source shielding should be incorporated into the brachytherapy planning system, it required calculation and comparison of the dose distribution around the applicator. This study used the Monte Carlo MCNP code to simulate the dose distribution in a water phantom that contained the Henschke applicator with one tandem and two ovoids. Three dwell positions of a high dose rate 192 Ir source were simulated by including and excluding the applicator. The mesh tally option of the MCNP was applied to facilitate the calculation of a large number of tallies in the phantom. The voxel size effect and the charge particle equilibrium were studied by comparing the results calculated with different tally options. The calculated results showed that the brachytherapy planning system overestimated the rectal dose and that the shielding material in the applicator contributed more than 40% to the rectal dose.

  8. Accuracy of dose planning for prostate radiotherapy in the presence of metallic implants evaluated by electron spin resonance dosimetry

    International Nuclear Information System (INIS)

    Alves, G.G.; Kinoshita, A.; Oliveira, H.F. de; Guimarães, F.S.; Amaral, L.L.; Baffa, O.

    2015-01-01

    Radiotherapy is one of the main approaches to cure prostate cancer, and its success depends on the accuracy of dose planning. A complicating factor is the presence of a metallic prosthesis in the femur and pelvis, which is becoming more common in elderly populations. The goal of this work was to perform dose measurements to check the accuracy of radiotherapy treatment planning under these complicated conditions. To accomplish this, a scale phantom of an adult pelvic region was used with alanine dosimeters inserted in the prostate region. This phantom was irradiated according to the planned treatment under the following three conditions: with two metallic prostheses in the region of the femur head, with only one prosthesis, and without any prostheses. The combined relative standard uncertainty of dose measurement by electron spin resonance (ESR)/alanine was 5.05%, whereas the combined relative standard uncertainty of the applied dose was 3.35%, resulting in a combined relative standard uncertainty of the whole process of 6.06%. The ESR dosimetry indicated that there was no difference (P>0.05, ANOVA) in dosage between the planned dose and treatments. The results are in the range of the planned dose, within the combined relative uncertainty, demonstrating that the treatment-planning system compensates for the effects caused by the presence of femur and hip metal prostheses

  9. Accuracy of dose planning for prostate radiotherapy in the presence of metallic implants evaluated by electron spin resonance dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Alves, G.G. [Departamento de Física, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP (Brazil); Kinoshita, A. [Departamento de Física, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP (Brazil); Universidade Sagrado Coração, Bauru, SP (Brazil); Oliveira, H.F. de; Guimarães, F.S.; Amaral, L.L. [Serviço de Radioterapia, Hospital das Clínicas, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP (Brazil); Baffa, O. [Departamento de Física, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP (Brazil)

    2015-05-26

    Radiotherapy is one of the main approaches to cure prostate cancer, and its success depends on the accuracy of dose planning. A complicating factor is the presence of a metallic prosthesis in the femur and pelvis, which is becoming more common in elderly populations. The goal of this work was to perform dose measurements to check the accuracy of radiotherapy treatment planning under these complicated conditions. To accomplish this, a scale phantom of an adult pelvic region was used with alanine dosimeters inserted in the prostate region. This phantom was irradiated according to the planned treatment under the following three conditions: with two metallic prostheses in the region of the femur head, with only one prosthesis, and without any prostheses. The combined relative standard uncertainty of dose measurement by electron spin resonance (ESR)/alanine was 5.05%, whereas the combined relative standard uncertainty of the applied dose was 3.35%, resulting in a combined relative standard uncertainty of the whole process of 6.06%. The ESR dosimetry indicated that there was no difference (P>0.05, ANOVA) in dosage between the planned dose and treatments. The results are in the range of the planned dose, within the combined relative uncertainty, demonstrating that the treatment-planning system compensates for the effects caused by the presence of femur and hip metal prostheses.

  10. Study of the suitability of Israeli household salt for retrospective dosimetry

    International Nuclear Information System (INIS)

    Datz, Hanan; Druzhyna, Sofia; Orion, Itzhak; Oster, Leonid; Horowitz, Yigal

    2016-01-01

    The first results of an in-depth evaluation of the practical potential of common household Israeli salt as a retrospective dosemeter in the event of a nuclear accident or terror attack are presented. Ten brands of salt were investigated with emphasis on four of the best-selling brands that constitute 76 % of the total consumer market. Eight of the ten brands show similar glow curves with two main glow peaks at maximum temperatures of ∼176 deg. C and ∼225 deg. C measured at a heating rate of 1 deg. C s -1 . Chemical analysis of three major brands indicates substantial impurity levels of 200-500 ppm of Ca, K, Mg and S and significant differences of additional ppm trace impurities, which lead to an ∼50 % difference in the TL response of the three major brands. Fading in the dark is in significant but under room light is of the order of 35 % per day. The dose response is linear/supralinear with the threshold of supralinearity at ∼0.01 Gy reaching maximum value of ∼4 at 0.5-1 Gy for two of the major brands. The precision of repeated measurements is ∼10 % (1 SD), but the accuracy of dose assessment under field conditions requires further study. (authors)

  11. Application of numerical analysis methods to thermoluminescence dosimetry

    International Nuclear Information System (INIS)

    Gomez Ros, J. M.; Delgado, A.

    1989-01-01

    This report presents the application of numerical methods to thermoluminescence dosimetry (TLD), showing the advantages obtained over conventional evaluation systems. Different configurations of the analysis method are presented to operate in specific dosimetric applications of TLD, such as environmental monitoring and mailed dosimetry systems for quality assurance in radiotherapy facilities. (Author) 10 refs

  12. The EURADOS/CONRAD activities on radiation protection dosimetry in medicine

    International Nuclear Information System (INIS)

    Vanhavere, F.; Struelens, L.; Bordy, J.M.; Daures, J.; Denozieres, M.; Buls, N.; Clerinx, P.; Carinou, E.; Clairand, I.; Debroas, J.; Donadille, L.; Itie, C.; Ginjaume, M.; Jansen, J.; Jaervinen, H.; Miljanic, S.; Ranogajec-Komor, M.; Nikodemova, D.; Rimpler, A.; Sans Merce, M.; D'Errico, F.

    2008-01-01

    Full text: This presentation gives an overview on the research activities that EURADOS coordinates in the field of radiation protection dosimetry in medicine. EURADOS is an organization founded in 1981 to advance the scientific understanding and the technical development of the dosimetry of ionising radiation in the fields of radiation protection, radiobiology, radiation therapy and medical diagnosis by promoting collaboration between European laboratories. EURADOS operates by setting up Working Groups dealing with particular topics. Currently funded through the CONRAD project of the 6th EU Framework Programme, EURADOS has working groups on Computational Dosimetry, Internal Dosimetry, Complex mixed radiation fields at workplaces, and Radiation protection dosimetry of medical staff. The latter working group coordinates and promotes European research for the assessment of occupational exposures to staff in therapeutic and diagnostic radiology workplaces. Research is coordinated by sub-groups covering three specific areas: 1: Extremity dosimetry in nuclear medicine and interventional radiology: this sub-group coordinates investigations in the specific fields of the hospitals and studies of doses to different parts of the hands, arms, legs and feet; 2: Practice of double dosimetry: this sub-group reviews and evaluates the different methods and algorithms for the use of dosemeters placed above and below lead aprons, especially to determine personal doses to cardiologists during cardiac catheterisation, but also in CT-fluoroscopy and some nuclear medicine developments (e.g. use of Re-188); and 3: Use of electronic personal dosemeters in interventional radiology: this sub-group coordinates investigations in laboratories and hospitals, and intercomparisons with passive dosemeters with the aim to enable the formulation of standards. (author)

  13. The Vinca dosimetry experiment

    International Nuclear Information System (INIS)

    1962-03-01

    On 15 October 1958 there occurred a very brief uncontrolled run of the zero-power reactor at the Boris Kidric Institute of Nuclear Science, Vinca, near Belgrade, Yugoslavia. During this run six persons received various doses of radiation. They were subsequently given medical treatment of a novel kind at the Curie Hospital, Paris. In atomic energy operations to date, very few accidents involving excessive radiation exposure to human beings have occurred. In fact, the cases of acute radiation injury are limited to about 30 known high exposures, few of which were in the lethal or near-lethal range. Since direct experiment to determine the effects of ionizing radiation on man is unacceptable, information on these effects has to be based on a consideration of data relating to accidental exposures, viewed in the light of the much more extensive data obtained from experiments on animals. Therefore, any direct information on the effects of radiation on humans is very valuable. The international dosimetry project described in this report was carried out at Vinca, Yugoslavia, under the auspices of the International Atomic Energy Agency to determine the precise amount of radiation to which the persons had been exposed during the accident. These dosimetry data, together with the record of the carefully observed clinical effects, are of importance both for the scientific study of radiation effects on man and for the development of methods of therapy. The experiment and measurements were carried out at the end of April 1960. The project formed part of the Agency's research programme in the field of health and safety. The results of the experiment are made available through this report to all Member States

  14. Dosimetry in intravascular brachytherapy

    International Nuclear Information System (INIS)

    Campos, Laelia Pumilla Botelho

    2000-03-01

    Among the cardiovascular diseases responsible for deaths in the adult population in almost all countries of the world, the most common is acute myocardial infarction, which generally occurs because of the occlusion of one or more coronary arteries. Several diagnostic techniques and therapies are being tested for the treatment of coronary artery disease. Balloon angioplasty has been a popular treatment which is less invasive than traditional surgeries involving revascularization of the myocardium, thus promising a better quality of life for patients. Unfortunately, the rate of restenosis (re-closing of the vessel) after balloon angioplasty is high (approximately 30-50% within the first year after treatment).Recently, the idea of delivering high radiation doses to coronary arteries to avoid or delay restenosis has been suggested. Known as intravascular brachytherapy, the technique has been used with several radiation sources, and researchers have obtained success in decreasing the rate of restenosis in some patient populations. In order to study the radiation dosimetry in the patient and radiological protection for the attending staff for this therapy, radiation dose distributions for monoenergetic electrons and photons (at nine discrete energies) were calculated for blood vessels of diameter 0.15, o,30 and 0.45 cm with balloon and wire sources using the radiation transport code MCNP4B. Specific calculations were carried out for several candidate radionuclides as well. Two s tent sources (metallic prosthesis that put inside of patient's artery through angioplasty) employing 32 P are also simulated. Advantages and disadvantages of the various radionuclides and source geometries are discussed. The dosimetry developed here will aid in the realization of the benefits obtained in patients for this promising new technology. (author)

  15. Effects of dose fractionation on the response of alanine dosimetry

    International Nuclear Information System (INIS)

    Lundahl, Brad; Logar, John; Desrosiers, Marc; Puhl, James

    2014-01-01

    Alanine dosimetry is well established as a transfer standard and is becoming more prevalently used in routine dosimetry systems for radiation processing. Many routine measurement applications in radiation processing involve absorbed dose measurements resulting from fractioned exposures to ionizing radiation. Fractioning of absorbed dose is identified as an influence quantity (ISO/ASTM, 2013). This paper reports on study results of absorbed dose fractioning characteristics of alanine for gamma and high energy electron beam radiation sources. The results of this study indicate a radiation response difference due to absorbed dose fractioning in response can be observed after four fractionations for high-energy electron beams and no difference up to seven fractions for gamma rays using an ANOVA evaluation method. - Highlights: • Fractioning effects signaled in electron beam using an ANOVA at 6 equal increments. • Fractioning effects not signaled in gamma using an ANOVA up to 7 equal increments. • Insensitivity of alanine to dose fractioning indicates nominal impact on calibration

  16. Reproductive function and biological dosimetry prospective study of young thyroid differentiated cancer patients treated with I-131

    International Nuclear Information System (INIS)

    Di Giorgio, Marina; Vallerga, Maria B.; Taja, Maria R.; Radl, Analia; Chebel, Graciela; Fadel, Ana M.; Gutierrez, Silvia; Normandi, Eduardo; Levalle, Oscar; Kundt, Miriam

    2008-01-01

    Full text: The administration of I-131 in the management of differentiated thyroid cancer (DTC) is a well established practice. As the spermatogonia is highly sensitive to radiation, large doses of internal radiation could result in adverse effects on reproductive function such as oligo/azoospermia and infertility. During spermiogenesis, mammalian chromatin undergoes replacement of nuclear histones by protamines, which yields a DNA sixfold more highly condensed in spermatozoa than in mitotic chromosomes. The structure of this highly packaged chromatin shows a low binding capacity for several fluoro chromes and dyes such as chromo mycin A 3 (CMA 3 ). The aim of this study is to assess the correlation between reproductive function (endocrine and exocrine testicular function, and levels of CMA 3 stainability) and biological dosimetry in a prospective study of 4 young DTC patients treated with I-131. In this context, a background level of CMA 3 binding in mature human sperm was established. It revealed a variable accessibility of CMA 3 to the DNA that is dependant on packaging quality and thus, indicative of protamine deficiency. The identification of altered stainability suggests DNA damage as well as epigenetic effects, which may be indicators of male infertility. Transient impairment of spermatogenesis associated with an increase in FSH, an altered spermiogram and even azoospermia was observed after the administration of cumulative activities. Overall, testosterone levels were preserved, except in one case, which presented a drastically diminished value associated with an increase in LH level. As peripheral blood lymphocytes and spermatogonia have equivalent radiosensitivity (interphase death) we hypothesize that the knowledge of DNA damage recovery in peripheral lymphocytes could correlate with spermatogonia recovery and with FSH evolution. Therefore, a prospective study on the decline of unstable chromosome aberrations is being conducted, considering the damage

  17. Effect of processor temperature on film dosimetry.

    Science.gov (United States)

    Srivastava, Shiv P; Das, Indra J

    2012-01-01

    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(max.), 10 × 10 cm(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°C (85-105°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. Copyright © 2012 American Association of Medical Dosimetrists. Published by Elsevier Inc. All rights reserved.

  18. Effect of processor temperature on film dosimetry

    International Nuclear Information System (INIS)

    Srivastava, Shiv P.; Das, Indra J.

    2012-01-01

    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 max. , 10 × 10 cm 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°C (85–105°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. Dosimetric evaluation of semiconductor detectors for application in neutron dosimetry and microdosimetry in nuclear reactor and radiosurgical facilities

    International Nuclear Information System (INIS)

    Cardenas, Jose Patricio Nahuel

    2010-01-01

    The main objective of this research is the dosimetric evaluation of semiconductor components (surface barrier detectors and PIN photodiodes) for applications in dose equivalent measurements on low dose fields (fast and thermal fluxes) using an AmBe neutron source, the IEA-R1 reactor neutrongraphy facility (epithermal and thermal fluxes) and the Critical Unit facility IPEN/MB-01 (fast fluxes). As moderator compound to fast neutrons flux from the AmBe source was used paraffin and boron and polyethylene as converter for thermal and fast neutrons measurements. The resulting fluxes were used to the irradiation of semiconductor components (SSB - Surface Barrier Detector and PIN photodiodes). A mixed converter made of a borated polyethylene foil (Kodak) was also used. Monte Carlo simulation methodology was employed to evaluate analytically the optimal paraffin thickness. The obtained results were similar to the experimental data and allowed the evaluation of emerging neutron flux from moderator, as well as the fast neutron flux reaching the polyethylene covering the semiconductor sensitive surface. Gamma radiation levels were evaluated covering the whole detector with cadmium foil 1 mm thick, allowing thermal neutrons blockage and gamma radiation measurements. The IPEN/MB-01 facility was employed to evaluate the detector response for high neutron flux. The results were in good agreement with other studies published. Using the obtained spectra an approach to dose equivalent calculation was established. (author)

  20. Dosimetry assessment of DNA damage by Auger-emitting radionuclides: Experimental and Monte Carlo studies

    Science.gov (United States)

    Di Maria, S.; Belchior, A.; Pereira, E.; Quental, L.; Oliveira, M. C.; Mendes, F.; Lavrado, J.; Paulo, A.; Vaz, P.

    2017-11-01

    Recently there has been considerable effort to investigate the potential use and efficacy of Auger-electron emitters in targeted radiotherapy. Auger electrons travel a short distance within human tissues (at nano-scale level) and, therefore, if an Auger-emitting radionuclide is transported to the cell nucleus it will cause enhanced DNA damage. Among the Auger-emitting radionuclides, 125I is of particular interest, as it emits about 25 electrons per decay. 99mTc only emits 5 electrons per decay, but presents some attractive characteristics such as a short half-life, easy procurement and availability and ideal imaging properties for therapy monitoring. In order to study the dosimetric behavior of these two radionuclides (125I and 99mTc) at nano-scale sizes and given the DNA-intercalation properties of Acridine Orange (AO), we have designed 99mTc (I)-tricarbonyl complexes and 125I-heteroaromatic compounds that contain AO derivatives, in order to promote a closer proximity between the radionuclides and the DNA structure. With the aim to have an insight on the relevance of these radiolabelled compounds for DNA-targeted Auger therapy, different aspects were investigated: i) their ability to cause DNA strand breaks; ii) the influence of the two different radionuclides in DNA damage; iii) the effect of the distance between the AO intercalating unit and the radioactive atom (99mTc or 125I). To address these issues several studies were carried out encompassing the evaluation of plasmid DNA damage, molecular docking and nanodosimetric Monte Carlo modelling and calculations. Results show that the two classes of compounds are able to induce DNA double strand breaks (dsb), but the number of DNA damages (e.g. dsb yield) is strongly dependent on the linker used to attach the Auger emitting radionuclide (125I or 99mTc) to the AO moiety. In addition, nanodosimetric calculations confirm a strong gradient of the absorbed energy with the DNA-radionuclide distance for the two

  1. Development and current state of dosimetry in Cuba

    International Nuclear Information System (INIS)

    Prieto Miranda, E.F.; Cuesta Fuente, G.; Chavez Ardanza, A.

    1999-01-01

    In Cuba, the application of the radiation technologies has been growing in the last years, and at present there are several dosimetry systems with different ranges of absorbed dose. Diverse researches were carried out on high dose dosimetry with the following dosimetry systems: Fricke, ceric-cerous sulfate, ethanol-chlorobenzene, cupric sulfate and Perspex (Red 4034 AE and Clear HX). In this paper the development achieved during the last 15 years in the high dose dosimetry for radiation processing in Cuba is presented, as well as, the current state of different dosimetry systems employed for standardization and for process control. The paper also reports the results of dosimetry intercomparison studies that were performed with the Ezeiza Atomic Center of Argentine and the International Dose Assurance Service (IDAS) of IAEA. (author)

  2. Neutron personal dosimetry: state-of-art

    International Nuclear Information System (INIS)

    Spurný, František

    2005-03-01

    State-of-art of the personal neutron dosimetry is presented, analysed and discussed. Particular attention is devoted to the problems of this type of the dosimetry of external exposure for radiation fields at nuclear power plants. A review of general problems of neutron dosimetry is given and the active individual dosimetry methods available and/or in the stage of development are briefly reviewed. Main attention is devoted to the analysis of the methods available for passive individual neutron dosimetry. The characteristics of these dosemeters were studied and are compared: their energy response functions, detection thresholds and the highest detection limits, the linearity of response, the influence of environmental factors, etc. Particular attention is devoted to their behavior in reactor neutron fields. It is concluded that the choice of the neutron personal dosemeter depends largely on the conditions in which the instrument should be used (neutron spectrum, the level of exposure and the exposure rate, etc.). The results obtained with some of these dosemeters during international intercomparisons are also presented. Particular attention is paid to the personal neutron dosimeter developed and routinely used by National Personal Dosimetry Service Ltd. in the Czech Republic. (author)

  3. Dosimetry quality audit of high energy photon beams in greek radiotherapy centers

    International Nuclear Information System (INIS)

    Hourdakis, Constantine J.; Boziari, A.

    2008-01-01

    Background and purpose: Dosimetry quality audits and intercomparisons in radiotherapy centers is a useful tool in order to enhance the confidence for an accurate therapy and to explore and dissolve discrepancies in dose delivery. This is the first national comprehensive study that has been carried out in Greece. During 2002 - 2006 the Greek Atomic Energy Commission performed a dosimetry quality audit of high energy external photon beams in all (23) Greek radiotherapy centers, where 31 linacs and 13 Co-60 teletherapy units were assessed in terms of their mechanical performance characteristics and relative and absolute dosimetry. Materials and Methods: The quality audit in dosimetry of external photon beams took place by means of on-site visits, where certain parameters of the photon beams were measured, calculated and assessed according to a specific protocol and the IAEA TRS 398 dosimetry code of practice. In each radiotherapy unit (Linac or Co-60), certain functional parameters were measured and the results were compared to tolerance values and limits. Doses in water under reference and non reference conditions were measured and compared to the stated values. Also, the treatment planning systems (TPS) were evaluated with respect to irradiation time calculations. Results: The results of the mechanical tests, dosimetry measurements and TPS evaluation have been presented in this work and discussed in detail. This study showed that Co-60 units had worse performance mechanical characteristics than linacs. 28% of all irradiation units (23% of linacs and 42% of Co-60 units) exceeded the acceptance limit at least in one mechanical parameter. Dosimetry accuracy was much worse in Co60 units than in linacs. 61% of the Co60 units exhibited deviations outside ±3% and 31% outside ±5%. The relevant percentages for the linacs were 24% and 7% respectively. The results were grouped for each hospital and the sources of errors (functional and human) have been investigated and

  4. Dosimetry quality audit of high energy photon beams in greek radiotherapy centers.

    Science.gov (United States)

    Hourdakis, Constantine J; Boziari, A

    2008-04-01

    Dosimetry quality audits and intercomparisons in radiotherapy centers is a useful tool in order to enhance the confidence for an accurate therapy and to explore and dissolve discrepancies in dose delivery. This is the first national comprehensive study that has been carried out in Greece. During 2002--2006 the Greek Atomic Energy Commission performed a dosimetry quality audit of high energy external photon beams in all (23) Greek radiotherapy centers, where 31 linacs and 13 Co-60 teletherapy units were assessed in terms of their mechanical performance characteristics and relative and absolute dosimetry. The quality audit in dosimetry of external photon beams took place by means of on-site visits, where certain parameters of the photon beams were measured, calculated and assessed according to a specific protocol and the IAEA TRS 398 dosimetry code of practice. In each radiotherapy unit (Linac or Co-60), certain functional parameters were measured and the results were compared to tolerance values and limits. Doses in water under reference and non reference conditions were measured and compared to the stated values. Also, the treatment planning systems (TPS) were evaluated with respect to irradiation time calculations. The results of the mechanical tests, dosimetry measurements and TPS evaluation have been presented in this work and discussed in detail. This study showed that Co-60 units had worse performance mechanical characteristics than linacs. 28% of all irradiation units (23% of linacs and 42% of Co-60 units) exceeded the acceptance limit at least in one mechanical parameter. Dosimetry accuracy was much worse in Co60 units than in linacs. 61% of the Co60 units exhibited deviations outside +/-3% and 31% outside +/-5%. The relevant percentages for the linacs were 24% and 7% respectively. The results were grouped for each hospital and the sources of errors (functional and human) have been investigated and discussed in details. This quality audit proved to be a

  5. Dosimetry in radiotherapy. V.1

    International Nuclear Information System (INIS)

    1988-01-01

    A series of symposia on dosimetry in medicine and biology have been held by the IAEA in co-operation with WHO. The present symposium was the first one focusing on ''Dosimetry in Radiotherapy''. The papers presented reflected the different steps in the calibration chain such as the calibration standards established by the National Standards Laboratories and the conversion of the reading of calibrated instruments to the desired quantity, i.e. absorbed dose to water at a reference point in the user's beam at the radiotherapy clinic. The programme further examined the procedures necessary for optimization of the treatment of the patient, such as treatment planning methods, dose distribution studies, new techniques of dose measurement, improvements in the physical dose distributions/conformation therapy and special problems involved in total body treatments. Results of quality assurance in radiotherapy were presented from local hospitals as well as from national and international studies. Refs, figs and tabs

  6. Dosimetry in radiotherapy. V.2

    International Nuclear Information System (INIS)

    1988-01-01

    A series of symposia on dosimetry in medicine and biology have been held by the IAEA in co-operation with WHO. The present symposium was the first one focusing on ''Dosimetry in Radiotherapy''. The papers presented reflected the different steps in the calibration chain such as the calibration standards established by the National Standards Laboratories and the conversion of the reading of calibrated instruments to the desired quantity, i.e. absorbed dose to water at a reference point in the user's beam at the radiotherapy clinic. The programme further examined the procedures necessary for optimization of the treatment of the patient, such as treatment planning methods, dose distribution studies, new techniques of dose measurement, improvements in the physical dose distributions/conformation therapy and special problems involved in total body treatments. Results of quality assurance in radiotherapy were presented from local hospitals as well as from national and international studies. Refs, figs and tabs

  7. Radiation risk assessment in neonatal radiographic examinations of the chest and abdomen: a clinical and Monte Carlo dosimetry study

    International Nuclear Information System (INIS)

    Makri, T; Yakoumakis, E; Papadopoulou, D; Gialousis, G; Theodoropoulos, V; Sandilos, P; Georgiou, E

    2006-01-01

    Seeking to assess the radiation risk associated with radiological examinations in neonatal intensive care units, thermo-luminescence dosimetry was used for the measurement of entrance surface dose (ESD) in 44 AP chest and 28 AP combined chest-abdominal exposures of a sample of 60 neonates. The mean values of ESD were found to be equal to 44 ± 16 μGy and 43 ± 19 μGy, respectively. The MCNP-4C2 code with a mathematical phantom simulating a neonate and appropriate x-ray energy spectra were employed for the simulation of the AP chest and AP combined chest-abdominal exposures. Equivalent organ dose per unit ESD and energy imparted per unit ESD calculations are presented in tabular form. Combined with ESD measurements, these calculations yield an effective dose of 10.2 ± 3.7 μSv, regardless of sex, and an imparted energy of 18.5 ± 6.7 μJ for the chest radiograph. The corresponding results for the combined chest-abdominal examination are 14.7 ± 7.6 μSv (males)/17.2 ± 7.6 μSv (females) and 29.7 ± 13.2 μJ. The calculated total risk per radiograph was low, ranging between 1.7 and 2.9 per million neonates, per film, and being slightly higher for females. Results of this study are in good agreement with previous studies, especially in view of the diversity met in the calculation methods

  8. Reproductive function and biological dosimetry prospective study of young thyroid differentiated cancer patients treated with I-131

    International Nuclear Information System (INIS)

    Di Giorgio, M.; Vallerga, M.B.; Taja, M.R.; Radl, A.; Chebel, Graciela; Fadel, Ana Maria; Gutierrez, Silvia; Normandi, Eduardo; Levalle, Oscar; Kundt, Miriam

    2011-01-01

    The administration of I-131 in the management of differentiated thyroid cancer (DTC) is a well established practice. As the spermatogonia is highly sensitive to radiation, large doses of internal radiation could result in adverse effects on reproductive function such as oligo/azoospermia and infertility. During spermiogenesis, mammalian chromatin undergoes replacement of nuclear histones by protamines, which yields a DNA sixfold more highly condensed in spermatozoa than in mitotic chromosomes. The structure of this highly packaged chromatin shows a low binding capacity for several fluorochromes and dyes such as chromomycin A3 (CMA3). The aim of this study is to assess the correlation between reproductive function (endocrine and exocrine testicular function, and levels of CMA3 stainability) and biological dosimetry in a prospective study of 4 young DTC patients treated with I-131. In this context, a background level of CMA3 binding in mature human sperm was established. It revealed a variable accessibility of CMA3 to the DNA that is dependant on packaging quality and thus, indicative of protamine deficiency. The identification of altered stainability suggests DNA damage as well as epigenetic effects, which may be indicators of male infertility. Transient impairment of spermatogenesis associated with an increase in FSH, an altered spermiogram and even azoospermia was observed after the administration of cumulative activities. Overall, testosterone levels were preserved, except in one case, which presented a drastically diminished value associated with an increase in LH level. As peripheral blood lymphocytes and spermatogonia have equivalent radiosensitivity (interphase death) we hypothesize that the knowledge of DNA damage recovery in peripheral lymphocytes could correlate with spermatogonia recovery and with FSH evolution. (authors)

  9. Modeling the dosimetry of organ-at-risk in head and neck IMRT planning: An intertechnique and interinstitutional study

    Energy Technology Data Exchange (ETDEWEB)

    Lian, Jun, E-mail: jun-lian@med.unc.edu; Chera, Bhishamjit S.; Chang, Sha [Department of Radiation Oncology, The University of North Carolina, Chapel Hill, North Carolina 27599 (United States); Yuan, Lulin, E-mail: lulin.yuan@duke.edu; Yoo, David P.; Yin, FangFang; Wu, Q. Jackie, E-mail: jackie.wu@duke.edu [Department of Radiation Oncology, Duke University, Durham, North Carolina 27710 (United States); Ge, Yaorong [Department of Software and Information Systems, The University of North Carolina, Charlotte, North Carolina 28223 (United States)

    2013-12-15

    Purpose: To build a statistical model to quantitatively correlate the anatomic features of structures and the corresponding dose-volume histogram (DVH) of head and neck (HN) Tomotherapy (Tomo) plans. To study if the model built upon one intensity modulated radiation therapy (IMRT) technique (such as conventional Linac) can be used to predict anticipated organs-at-risk (OAR) DVH of patients treated with a different IMRT technique (such as Tomo). To study if the model built upon the clinical experience of one institution can be used to aid IMRT planning for another institution. Methods: Forty-four Tomotherapy intensity modulate radiotherapy plans of HN cases (Tomo-IMRT) from Institution A were included in the study. A different patient group of 53 HN fixed gantry IMRT (FG-IMRT) plans was selected from Institution B. The analyzed OARs included the parotid, larynx, spinal cord, brainstem, and submandibular gland. Two major groups of anatomical features were considered: the volumetric information and the spatial information. The volume information includes the volume of target, OAR, and overlapped volume between target and OAR. The spatial information of OARs relative to PTVs was represented by the distance-to-target histogram (DTH). Important anatomical and dosimetric features were extracted from DTH and DVH by principal component analysis. Two regression models, one for Tomotherapy plan and one for IMRT plan, were built independently. The accuracy of intratreatment-modality model prediction was validated by a leave one out cross-validation method. The intertechnique and interinstitution validations were performed by using the FG-IMRT model to predict the OAR dosimetry of Tomo-IMRT plans. The dosimetry of OARs, under the same and different institutional preferences, was analyzed to examine the correlation between the model prediction and planning protocol. Results: Significant patient anatomical factors contributing to OAR dose sparing in HN Tomotherapy plans have been

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

    Energy Technology Data Exchange (ETDEWEB)

    Richley, L; John, A C; Coomber, H; Fletcher, S, E-mail: lucy.richley@uhbristol.nhs.u [Bristol Haematology and Oncology Centre, Bristol, BS2 8ED (United Kingdom)

    2010-05-07

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

  11. Reconstructive dosimetry and radiation doses evaluation of members of the public due to radiological accident in industrial radiography

    International Nuclear Information System (INIS)

    Lima, Camila Moreira Araujo de

    2016-01-01

    Radiological accidents have occurred mainly in the practices recognized as high risk radiological and classified by the IAEA as Categories 1 and 2, and highlighted the radiotherapy, industrial irradiators and industrial radiography. In Brazil, since there were five major cases in industrial radiography, which involved 7 radiation workers and 19 members of the public, causing localized radiation lesions on the hands and fingers. One of these accidents will be the focus of this work. In this accident, a 192 Ir radioactive source was exposed for more than 8 hours in the workplace inside a company, exposing radiation workers, individuals of the public and people from the surrounding facilities, including children of a school. The radioactive source was also handled by a security worker causing severe radiation injuries in the hand and fingers. In this paper, the most relevant and used techniques of reconstructive dosimetry internationally are presented. To estimate the radiation doses received by exposed individuals in various scenarios of radiological accident in focus, the following computer codes were used: Visual Monte Carlo Dose Calculation (VMC), Virtual Environment for Radiological and Nuclear Accidents Simulation (AVSAR) and RADPRO Calculator. Through these codes some radiation doses were estimated, such as, 33.90 Gy in security worker's finger, 4.47 mSv in children in the school and 55 to 160 mSv for workers in the company during the whole day work. It is intended that this work will contribute to the improvement of dose reconstruction methodology for radiological accidents, having then more realist radiation doses. (author)

  12. Introduction of a single chip TLD system for patient dosimetry

    International Nuclear Information System (INIS)

    Hranitzky, C.; Halda, M.; Mueller, G.; Stadtmann, H.; Obryk, B.

    2008-01-01

    A thermoluminescence dosimetry system with single detector chips was developed for patient dosimetry applications. LiF:Mg,Cu,P detector chips, dosimetry protocol, calibration, and dose calculation were prepared for measurements inside phantoms for determining organ and effective doses in medical diagnostic examinations. The first step was optimizing the readout time-temperature-profile for reaching a well resolved dosimetric peak and stability of the glow curves. A number of parameters was varied for the optimization process, e.g. preheating and heating rate. Individual chip sensitivities, residual dose and dose linearity were studied for establishing a reliable and accurate TL dosimetry system. (author)

  13. Dosimetry and Calibration Section

    International Nuclear Information System (INIS)

    Otto, T.

    1999-01-01

    The Dosimetry and Calibration Section fulfils two tasks within CERN's Radiation Protection Group: the Individual Dosimetry Service monitors more than 5000 persons potentially exposed to ionizing radiation on the CERN sites, and the Calibration Laboratory verifies throughout the year, at regular intervals, over 1000 instruments, monitors, and electronic dosimeters used by RP Group. The establishment of a Quality Assurance System for the Individual Dosimetry Service, a requirement of the new Swiss Ordinance for personal dosimetry, put a considerable workload on the section. Together with an external consultant it was decided to identify and then describe the different 'processes' of the routine work performed in the dosimetry service. The resulting Quality Manual was submitted to the Federal Office for Public Health in Bern in autumn. The CERN Individual Dosimetry Service will eventually be officially endorsed after a successful technical test in March 1999. On the technical side, the introduction of an automatic development machine for gamma films was very successful. It processes the dosimetric films without an operator being present, and its built-in regeneration mechanism keeps the concentration of the processing chemicals at a constant level

  14. WE-G-BRA-01: Development of a Web-Based Dosimetry Training Tool for Therapy and Dosimetry Education.

    Science.gov (United States)

    Schreiber, E; Hannum, W; Zeman, E; Kostich, M; Tracton, G; Church, J; Dean, R; Adams, R

    2012-06-01

    Training in clinical dosimetry is an important component of radiation therapy, dosimetry, and medical physics training programs. Based on our in-house treatment planning system, PLanUNC, we are developing and assessing a web-based dosimetry teaching tool to augment existing training programs. We surveyed radiation therapy program directors to assess the need for clinical dosimetry training tools. Based on survey results, we are developing a web-based dosimetry-training tool consisting of 10 modules containing didactic content based on the ASRT curriculum, student assessment, and hands-on treatment planning exercises. External content specialists reviewed the self-paced modules for accuracy and content validity. Two external dosimetry students were observed as they completed three sections, and were interviewed in-depth to evaluate the modules. This qualitative analysis combined features of usability testing with formative evaluation of instructional products. We revised the modules based on these data. Our next phase, quantitative evaluation, will assess the effectiveness of the modules, the quality of the interactivity and the degree of student engagement when completing the modules. Sixty-four percent of program directors indicated they had insufficient local resources for dosimetry training, and over 90% indicated interest in web-based training tools as teaching supplements. External evaluators indicated module content was appropriate and accurate. Students indicated the modules were easy to use with clear and understandable content. They were engaged when using the modules and motivated by the interactive components. They placed value on the exercises and the feedback they received. Inter-institutional evaluation improves the quality and generalizability of instructional modules. Carefully designed online learning modules are viewed as effective teaching tools by dosimetry students. The clinical dosimetry teaching tool will be made accessible to therapy and

  15. The importance of BMI in dosimetry of 153Sm-EDTMP bone pain palliation therapy: A Monte Carlo study

    International Nuclear Information System (INIS)

    Fallahpoor, Maryam; Abbasi, Mehrshad; Asghar Parach, Ali; Kalantari, Faraz

    2017-01-01

    Using digital phantoms as an atlas compared to acquiring CT data for internal radionuclide dosimetry decreases patient overall radiation dose and reduces the required analysis effort and time for organ segmentation. The drawback is that the phantom may not match exactly with the patient. We assessed the effect of varying BMIs on dosimetry results for a bone pain palliation agent, 153 Sm-EDTMP. The simulation was done using the GATE Monte Carlo code. Female XCAT phantoms with the following different BMIs were employed: 18.6, 20.8, 22.1, 26.8, 30.3 and 34.7 kg/m 2 . S-factors (mGy/MBq.s) and SAFs (kg −1 ) were calculated for the dosimetry of the radiation from major source organs including spine, ribs, kidney and bladder into different target organs as well as whole body dosimetry from spine. The differences in dose estimates from different phantoms compared to those from the phantom with BMI of 26.8 kg/m 2 as the reference, were calculated for both gamma and beta radiations. The relative differences (RD) of the S-factors or SAFs from the values of reference phantom were calculated. RDs greater than 10% and 100% were frequent in radiations to organs for photon and beta particles, respectively. The relative differences in whole body SAFs from the reference phantom were 15.4%, 7%, 4.2%, −9.8% and −1.4% for BMIs of 18.6, 20.8, 22.1, 30.3 and 34.7 kg/m 2 , respectively. The differences in whole body S-factors for the phantoms with BMIs of 18.6, 20.8, 22.1, 30.3 and 34.7 kg/m 2 were 39.5%, 19.4%, 8.8%, −7.9% and −4.3%, respectively. The dosimetry of the gamma photons and beta particles changes substantially with the use of phantoms with different BMIs. The change in S-factors is important for dose calculation and can change the prescribed therapeutic dose of 153 Sm-EDTMP. Thus a phantom with BMI better matched to the patient is suggested for therapeutic purposes where dose estimates closer to those in the actual patient are required. - Highlights: • Internal

  16. A study of the efficacy of radioiodine therapy with individualized dosimetry in Graves' disease: need to retarget the radiation committed dose to the thyroid.

    Science.gov (United States)

    Schiavo, M; Bagnara, M C; Calamia, I; Bossert, I; Ceresola, E; Massaro, F; Giusti, M; Pilot, A; Pesce, G; Caputo, M; Bagnasco, M

    2011-03-01

    Although Iodine-131 (131I) therapy is fully validated for Graves' disease (GD), there is debate about radioiodine amount to be administered (prescribed activity), as well as the use of individualized dosimetry vs fixed 131I activity. The clinical outcome of 119 GD patients treated with 131I from 2003 to 2008 has been evaluated. The prescribed activity was calculated according to a dosimetric protocol taking into account several variables, including thyroid volume reduction during treatment. In addition, we performed a simulation according to other dosimetric protocols, by calculating the corresponding prescribed activities. The patients were followed up for at least 12 months after treatment. In the first period of observation (2003), a 120-200 Gray (Gy) radiation dose to the thyroid was prescribed, according to the guidelines published by the Italian Societies of Endocrinology, Nuclear Medicine and Medical Physics: hyperthyroidism cure with a single radioiodine administration was obtained in 53% of patients. This outcome raised up to 89% when a higher radiation dose to the target (200- 250 Gy) was prescribed, although the administered activities were still lower, as a rule, than the most commonly employed fixed activities (400-600 Mega-Becquerel--MBq). Our method showed a high level of individual dose optimisation, particularly when compared to simplified methods. In conclusion, the protocol adopted in this study ensures a satisfactory rate of hyperthyroidism cure, while administering quite low 131I activities, provided that an adequate committed radiation dose to the thyroid is prescribed. In this context, the dose indication given by the aforementioned guidelines should probably be revised.

  17. Study of new compounds for their application on free radicals EPR dosimetry

    International Nuclear Information System (INIS)

    Condes N, C.S.

    1996-01-01

    L- α alanine is an amino acid which has been used for electron and γ ray dosimetric purposes, when crystallites of L-α alanine are irradiated with ionizing radiation free radicals are produced. The yield of free radicals produced by irradiation of alanine crystals can be evaluated by EPR spectrometry, however when L- α alanine crystals are irradiated with thermal neutrons the yield of the free radicals produced is very low and in consequence it's EPR-signal response is poor. In this work we mixed L-α alanine together with some lithium compounds such as LiF, LiBO 2 , LiOH and Li 2 CO 3 . In this way when we irradiate the respective mixture of alanine-lithium with thermal neutrons, the nuclear reactions 6 Li (n,α)T and 10 B (n, α) 7 Li can be produced with a high probability. As a consequence α particles and recoil atoms emerging from the nuclear reactions can impinge on alanine molecules, producing extra free radicals. From the alanine-lithium mixtures obtained, we made dosemeters (30 mm long., 3.9 mm diameter) which were irradiated in the thermal column of the TRIGA Mark III Nuclear Reactor with a flux of thermal neutrons of 5 x 10 7 n/ cm 2 s. Irradiations were made at different periods. Experimental evaluations indicate that the mixtures can be used for dosimetric purposes. (Author)

  18. I-124 Imaging and Dosimetry

    Directory of Open Access Journals (Sweden)

    Russ Kuker

    2017-02-01

    Full Text Available Although radioactive iodine imaging and therapy are one of the earliest applications of theranostics, there still remain a number of unresolved clinical questions as to the optimization of diagnostic techniques and dosimetry protocols. I-124 as a positron emission tomography (PET radiotracer has the potential to improve the current clinical practice in the diagnosis and treatment of differentiated thyroid cancer. The higher sensitivity and spatial resolution of PET/computed tomography (CT compared to standard gamma scintigraphy can aid in the detection of recurrent or metastatic disease and provide more accurate measurements of metabolic tumor volumes. However the complex decay schema of I-124 poses challenges to quantitative PET imaging. More prospective studies are needed to define optimal dosimetry protocols and to improve patient-specific treatment planning strategies, taking into account not only the absorbed dose to tumors but also methods to avoid toxicity to normal organs. A historical perspective of I-124 imaging and dosimetry as well as future concepts are discussed.

  19. On-Board TL Dosimetry: Possibilities and Limitations

    International Nuclear Information System (INIS)

    Deme, S.; Apathy, I.; PAzmandi, T.

    2001-01-01

    Full text: The paper shortly deals with application of TLDs for dosimetry of ISS, e.g. personal dosimetry, phantom measurements, mapping, monitoring and neutron dosimetry. The main characteristics of the on-board and ground evaluation are compared. The main advantages and disadvantages of the on-board evaluation are summarised. Finally the planned future improvements of the Pille system are discussed like development of an RS485 interface for alternative data transfer, introduction of smaller dosimeters (capsules), use of a more use-friendly display (80 characters), application of internal memory instead of memory card and improvement of the dosimeter evaluation (glow curve fit, background subtraction). (author)

  20. Investigation of polymer composite for high dose dosimetry

    International Nuclear Information System (INIS)

    Pereira, E.L.M.; Batista, A.S.M.; Ribeiro, F.A.S.; Santos, A.P.; Faria, L.O.; Oliveira, A.H.

    2017-01-01

    Introduction: This paper presents the efficacy evaluation of PVDF and nanocomposites of the PVDF films for high gamma dosimetry. Our scope in this first part of our studies is the selection of the most promising film for future dosimetry trials, where the proportionality of response of the selected material will be investigated over a large range of doses and dose rates. Methods: Was prepared nanocomposites made by mixing Poly(vinylidene fluoride) (PVDF), zirconium oxide (ZrO 2 ) and multi-walled carbon nanotubes (MWCNTs) aiming to find dosimetric properties for applications in high dose dosimetry. The samples were irradiated with a Co-60 source at constant dose rate (16.7 kGy/h), with doses ranging from 100 to 2750 kGy. The UV-Vis and FTIR spectrophotometry have been used to monitor the appearing of C=C conjugated bonds and radio-oxidation of carbon (C=O). Results: FTIR spectrometry has that the absorbance intensities at 1715 cm -1 and 1730 cm -1 can be used for high dosimetry purposes for gamma doses ranging from 400 to 2750 kGy. In this range, it is possible to observe a linear relationship between Abs & Dose. Fading of signal was evaluated for one month and reproducibility in 2000 kGy dose. Conclusion: FTIR spectroscopic data revealed two optical absorption bands at 1715 cm -1 and 1730 cm -1 whose intensities are unambiguously related to gamma delivered dose ranging from 400 kGy to 2750 kGy. (author)

  1. A model for absorption determination of radioactive materials: application in the radio dosimetry and nutrition study

    International Nuclear Information System (INIS)

    Mesquita, C.H. de.

    1991-01-01

    A three-parameter model of the sigmoidal relationship is proposed to explain the food passage by intestinal tube. These parameters are: U = intestinal non-absorbed radioactivity; d parameter related to intestinal food dispersion; and t 50 = time to maximal appearance of material from the intestinal lumen. In order to illustrate the applications of this model and its validity, the absorption of 65 Zn from casein semi-purified diet was evaluated in rats. There was a good agreement between the predicted values and the experimental data when the sigmoidal component was added to the conventional multicompartimental equations. With this kind of model the time to maximal appearance (hours), the true absorption level, the fecal concentration and the intestinal dispersion of the ingested radioactivity material may be determined. (author)

  2. Study and characterization of dosimeter LiF:Mg,Cu,P for using in aeronautical dosimetry; Estudo e caracterizacao do dosimetro de LiF:Mg,Cu,P para utilizacao em dosimetria aeronautica

    Energy Technology Data Exchange (ETDEWEB)

    Flavia, Hanna, E-mail: hannasantana.f@gmail.com [Universidade Paulista (UNIP), Sao Jose dos Campos, SP (Brazil); Federico, Claudio; Lelis, Odair; Pereira, Heloisa; Pereira, Marlon, E-mail: claudiofederico@ieav.cta.br [Instituto de Estudos Avancados (EFA-A/IEAV), Sao Jose dos Campos, SP (Brazil). Div. de Fisica Aplicada

    2014-07-01

    The effects of cosmic ionizing radiation incidents in aircraft components and crews has been a source of concern and motivated increasingly studies and improvements in the area. The low dose rates involved in this radiation field in aircraft flight altitudes imply Dosimetric necessity of using materials with high efficiency of detection, to enable studies lower cumulative doses resulting in shorter routes or lower altitude. The choice of thermoluminescent dosimeters LiF: Mg, Cu, P was done by having a detection efficiency of about fifteen times higher than its predecessor (LiF: Mg, Ti), and therefore, applied in very low doses dosimetry, and environmental dosimetry . The implementation of the use of pair dosimetric TLD-600H and 700H-TLD will serve as support for testing and studies on the effects of low doses of cosmic radiation in environmental dosimetry applied in the aviation environment in the usual flight altitudes. In this paper are presented the results of development of a methodology for dosimetry low doses of gamma radiation and neutrons using the pair dosimetric TLD-600H and 700H-TLD. The results demonstrate a sensitivity of dosimeters well above the dosimeters LiF: Mg, Ti confirming its suitability for dosimetry of low doses.

  3. Influence of 320-detector-row volume scanning and AAPM report 111 CT dosimetry metrics on size-specific dose estimate: a Monte Carlo study.

    Science.gov (United States)

    Haba, Tomonobu; Koyama, Shuji; Kinomura, Yutaka; Ida, Yoshihiro; Kobayashi, Masanao

    2016-09-01

    The American Association of Physicists in Medicine (AAPM) task group 204 has recommended the use of size-dependent conversion factors to calculate size-specific dose estimate (SSDE) values from volume computed tomography dose index (CTDIvol) values. However, these conversion factors do not consider the effects of 320-detector-row volume computed tomography (CT) examinations or the new CT dosimetry metrics proposed by AAPM task group 111. This study aims to investigate the influence of these examinations and metrics on the conversion factors reported by AAPM task group 204, using Monte Carlo simulations. Simulations were performed modelling a Toshiba Aquilion ONE CT scanner, in order to compute dose values in water for cylindrical phantoms with 8-40-cm diameters at 2-cm intervals for each scanning parameter (tube voltage, bow-tie filter, longitudinal beam width). Then, the conversion factors were obtained by applying exponential regression analysis between the dose values for a given phantom diameter and the phantom diameter combined with various scanning parameters. The conversion factors for each scanning method (helical, axial, or volume scanning) and CT dosimetry method (i.e., the CTDI100 method or the AAPM task group 111 method) were in agreement with those reported by AAPM task group 204, within a percentage error of 14.2 % for phantom diameters ≥11.2 cm. The results obtained in this study indicate that the conversion factors previously presented by AAPM task group 204 can be used to provide appropriate SSDE values for 320-detector-row volume CT examinations and the CT dosimetry metrics proposed by the AAPM task group 111.

  4. Evaluation of Multiple-Sampling Function used with a Microtek flatbed scanner for Radiation Dosimetry Calibration of EBT2 Film

    International Nuclear Information System (INIS)

    Chang, Liyun; Ho, Sheng-Yow; Ding, Hueisch-Jy; Hwang, Ing-Ming; Chen, Pang-Yu; Lee, Tsair-Fwu

    2016-01-01

    The radiochromic EBT2 film is a widely used quality assurance device for radiation therapy. This study evaluated the film calibration performance of the multiple-sampling function, a function of the ScanWizard Pro scanning software provided by the manufacturer, when used with Microtek 9800XL plus (9800XL + ) flatbed scanner. By using the PDD method, each one of the eight EBT2 films, four delivered by 290 monitor unit (MU) and four by 88 MU via 6-MV photon beams, was tightly sandwiched in a 30 3 -cm 3 water equivalent polystyrene phantom prior to irradiation. Before and after irradiation, all films were scanned using the Microtek 9800XL + scanner with five different modes of the multiple-sampling function, which could generate the image with the averaged result of multiple-sampling. The net optical densities (netOD) on the beam central axis of film were assigned to corresponding depth doses for calibration. For each sampling mode with either delivered MU, the depth-dose uncertainty of a single film from repeated scans and that of a single scan of the four films were analyzed. Finally, the calibration error and the combined calibration uncertainty between film determined depth-doses and delivered depth-doses were calculated and evaluated for each sampling mode. All standard deviations and the calibration error were demonstrated to be unrelated to the number of sampling lines. The calibration error of the 2-line and 16-line mode was within 3 cGy and better than that of the other modes. The combined uncertainty of the 2-line mode was the lowest, which was generally less than 6 cGy except for the delivered dose around 100 cGy. The evaluation described herein revealed that the EBT2 film calibrated with the 2-line mode has relatively lower error, scanning time and combined uncertianty. Therefore, it is recommended for routine EBT2 film calibration and verification of treatment plans.

  5. Sandia National Laboratories Internal Dosimetry Technical Basis Manual (Rev 4)

    Energy Technology Data Exchange (ETDEWEB)

    Goke, Sarah Hayes [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Elliott, Nathan Ryan [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2014-09-01

    The Sandia National Laboratories’ Internal Dosimetry Technical Basis Manual is intended to provide extended technical discussion and justification of the internal dosimetry program at SNL. It serves to record the approach to evaluating internal doses from radiobioassay data, and where appropriate, from workplace monitoring data per the Department of Energy Internal Dosimetry Program Guide DOE G 441.1C. The discussion contained herein is directed primarily to current and future SNL internal dosimetrists. In an effort to conserve space in the TBM and avoid duplication, it contains numerous references providing an entry point into the internal dosimetry literature relevant to this program. The TBM is not intended to act as a policy or procedure statement, but will supplement the information normally found in procedures or policy documents. The internal dosimetry program outlined in this manual is intended to meet the requirements of Federal Rule 10CFR835 for monitoring the workplace and for assessing internal radiation doses to workers.

  6. Cell specific radiation dosimetry in skeleton from life-span carcinogenesis studies

    Energy Technology Data Exchange (ETDEWEB)

    Webster, S.S.J.

    1993-04-05

    The osteogenic sarcoma is the dominant life-threatening pathology in lifespan studies of beagles exposed to alpha-emitting bone-seeking radionuclides. It was deduced from these studies that certain skeletal sites are more prone to develop tumors. This project sought to determine the bone cells at risk and their cell-specific radiation dose. The cell-specific radiation dose values are related to loss and high Ra-226 and Pu-239 induced osteogenic sarcoma sites, to test different dose response hypothesis and predict the extent of effects in humans.

  7. Third conference on radiation protection and dosimetry

    International Nuclear Information System (INIS)

    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

  8. SNL RML recommended dosimetry cross section compendium

    Energy Technology Data Exchange (ETDEWEB)

    Griffin, P.J.; Kelly, J.G.; Luera, T.F. [Sandia National Labs., Albuquerque, NM (United States); VanDenburg, J. [Science and Engineering Associates, Inc., Albuquerque, NM (United States)

    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.

  9. Advances in electron dosimetry of irregular fields

    International Nuclear Information System (INIS)

    Mendez V, J.

    1998-01-01

    In this work it is presented an advance in Electron dosimetry of irregular fields for beams emitted by linear accelerators. At present diverse methods exist which are coming to apply in the Radiotherapy centers. In this work it is proposed a method for irregular fields dosimetry. It will be allow to calculate the dose rate absorbed required for evaluating the time for the treatment of cancer patients. Utilizing the results obtained by the dosimetric system, it has been possible to prove the validity of the method describe for 12 MeV energy and for square field 7.5 x 7.5 cm 2 with percentile error less than 1 % . (Author)

  10. TU-FG-201-06: Remote Dosimetric Auditing for Clinical Trials Using EPID Dosimetry: A Pilot Study

    Energy Technology Data Exchange (ETDEWEB)

    Miri, N; Legge, K; Greer, P [Newcastle University, Newcastle, NSW (Australia); Lehmann, J [Calvary Mater Newcastle, Newcastle, NSW (Australia); Vial, P [Liverpool Hospital, Sydney, NSW (Australia)

    2016-06-15

    Purpose: To perform a pilot study for remote dosimetric credentialing of intensity modulated radiation therapy (IMRT) based clinical trials. The study introduces a novel, time efficient and inexpensive dosimetry audit method for multi-center credentialing. The method employs electronic portal imaging device (EPID) to reconstruct delivered dose inside a virtual flat/cylindrical water phantom. Methods: Five centers, including different accelerator types and treatment planning systems (TPS), were asked to download two CT data sets of a Head and Neck (H&N) and Postprostatectomy (P-P) patients to produce benchmark plans. These were then transferred to virtual flat and cylindrical phantom data sets that were also provided. In-air EPID images of the plans were then acquired, and the data sent to the central site for analysis. At the central site, these were converted to DICOM format, all images were used to reconstruct 2D and 3D dose distributions inside respectively the flat and cylindrical phantoms using inhouse EPID to dose conversion software. 2D dose was calculated for individual fields and 3D dose for the combined fields. The results were compared to corresponding TPS doses. Three gamma criteria were used, 3%3mm-3%/2mm–2%/2mm with a 10% dose threshold, to compare the calculated and prescribed dose. Results: All centers had a high pass rate for the criteria of 3%/3 mm. For 2D dose, the average of centers mean pass rate was 99.6% (SD: 0.3%) and 99.8% (SD: 0.3%) for respectively H&N and PP patients. For 3D dose, 3D gamma was used to compare the model dose with TPS combined dose. The mean pass rate was 97.7% (SD: 2.8%) and 98.3% (SD: 1.6%). Conclusion: Successful performance of the method for the pilot centers establishes the method for dosimetric multi-center credentialing. The results are promising and show a high level of gamma agreement and, the procedure is efficient, consistent and inexpensive. Funding has been provided from Department of Radiation Oncology

  11. Feasibility and dosimetry studies for 18F-NOS as a potential PET radiopharmaceutical for inducible nitric oxide synthase in humans.

    Science.gov (United States)

    Herrero, Pilar; Laforest, Richard; Shoghi, Kooresh; Zhou, Dong; Ewald, Gregory; Pfeifer, John; Duncavage, Eric; Krupp, Kitty; Mach, Robert; Gropler, Robert

    2012-06-01

    Nitric oxide (NO), the end product of the inducible form of NO synthase (iNOS), is an important mediator of a variety of inflammatory diseases. Therefore, a radiolabeled iNOS radiopharmaceutical for assessing iNOS protein concentration as a marker for its activity would be of value to the study and treatment of NO-related diseases. We recently synthesized an (18)F-radiolabeled analog of the reversible NOS inhibitor, 2-amino-4-methylpyridine ((18)F-NOS), and confirmed its utility in a murine model of lung inflammation. To determine its potential for use in humans, we measured (18)F-NOS myocardial activity in patients after orthotopic heart transplantation (OHT) and correlated it with pathologic allograft rejection, tissue iNOS levels, and calculated human radiation dosimetry. Two groups were studied-a kinetic analysis group and a dosimetry group. In the kinetic analysis group, 10 OHT patients underwent dynamic myocardial (18)F-NOS PET/CT, followed by endomyocardial biopsy. Myocardial (18)F-NOS PET was assessed using volume of distribution; standardized uptake values at 10 min; area under the myocardial moment curve (AUMC); and mean resident time at 5, 10, and 30 min after tracer injection. Tissue iNOS levels were measured by immunohistochemistry. In the dosimetry group, the biodistribution and radiation dosimetry were calculated using whole-body PET/CT in 4 healthy volunteers and 12 OHT patients. The combined time-activity curves were used for residence time calculation, and organ doses were calculated with OLINDA. Both AUMC at 10 min (P < 0.05) and tissue iNOS (P < 0.0001) were higher in patients exhibiting rejection than in those without rejection. Moreover, the (18)F-NOS AUMC at 10 min correlated positively with tissue iNOS at 10 min (R(2) = 0.42, P < 0.05). (18)F-NOS activity was cleared by the hepatobiliary system. The critical organ was the bladder wall, with a dose of 95.3 μGy/MBq, and an effective dose of 15.9 μSv/MBq was calculated. Myocardial (18)F

  12. Study of the radiolysis of succinic acid - applications in the dosimetry of high doses

    International Nuclear Information System (INIS)

    Andrade e Silva, L.G.

    1978-01-01

    A study is made of the effect of the gama radiation dose and of particle size of succinic acid (fine powder of large crystals) in relation with the formation of CO 2 and CO + H 2 , which are the main gaseous products of radiolysis. A different yield of CO + H 2 is found when the succinic acid is used as powder compared to the material in the form of large crystals. The reason for this difference is searched, studying the influence of heating and sublimation of the succinic acid prior to irradiation. The influence, in the mentioned yield, of the surface area of succinic acid particles, of the presence of oxygen (air) and of the rapid recrystallization of the acid are also studied. The formation of intermediate species in the radiolysis of succinic acid is examined. The system used in ethanol-succinic acid at 77K. Analysis are made using an electronic paramagnetic resonance spectrometer. The possibility of using succinic acid as a dosimeter for high level gama radiation doses is discussed [pt

  13. Dosimetry of internal emitting: principles and perspectives of the MIRD technology; Dosimetria de emisores internos: principios y perspectivas de la metodologia MIRD

    Energy Technology Data Exchange (ETDEWEB)

    Ferro F, G. [Gerencia de Aplicaciones Nucleares en la Salud, Instituto Nacional de Investigaciones Nucleares, Salazar, Estado de Mexico C.P. 52045 (Mexico)

    1999-07-01

    The development of the radiopharmaceutical technology have multiplied the number of radioisotopes with applications in therapeutical nuclear medicine so known as Directed radiotherapy. Assuming the radiation is capable to produce noxious effects in the biological systems, it is important to evaluate appropriately the risks and benefits of the administration of radioactive agents in the patient. The outstanding parameter in this evaluation is the absorbed dose, which is product of the radiation emitted by a radionuclide that is localized or distributed to the interior of the human body in study and whose its estimation helps to predict the efficacy of the treatment. The scheme generalized of MIRD, it was formulated from thirty years ago for evaluating the interior dosimetry at level of organs.The finality of this work is to show the basic principles of the MIRD methodology and its perspectives using innovator tools as the dosimetry for dynamic masses, in particular the personnel dosimetry for the organs of each patient, the dosimetry for the small structures inside the organs (sub organic dosimetry), the distributions of doses in three dimensions (S voxel), the dosimetry at cellular level and the quantitative acquisition of pharmaceutical data. (Author)

  14. Dosimetry for radiation processing

    DEFF Research Database (Denmark)

    Miller, Arne

    1986-01-01

    During the past few years significant advances have taken place in the different areas of dosimetry for radiation processing, mainly stimulated by the increased interest in radiation for food preservation, plastic processing and sterilization of medical products. Reference services both by intern......During the past few years significant advances have taken place in the different areas of dosimetry for radiation processing, mainly stimulated by the increased interest in radiation for food preservation, plastic processing and sterilization of medical products. Reference services both...... by international organizations (IAEA) and national laboratories have helped to improve the reliability of dose measurements. Several dosimeter systems like calorimetry, perspex, and radiochromic dye films are being improved and new systems have emerged, e.g. spectrophotometry of dichromate solution for reference...... and sterilization dosimetry, optichromic dosimeters in the shape of small tubes for food processing, and ESR spectroscopy of alanine for reference dosimetry. In this paper the special features of radiation processing dosimetry are discussed, several commonly used dosimeters are reviewed, and factors leading...

  15. Recent progress in application of JAERI alanine/ESR dosimetry system

    International Nuclear Information System (INIS)

    Kojima, T.

    1995-01-01

    Feasibility studies of application of JAERI alanine/ESR dosimetry system were performed on radiotherapy level dosimetry, low dose-rate dosimetry for residual life estimation of cable insulators used in nuclear power facilities, and dose monitoring for electron processing. (author)

  16. An optically stimulated luminescence study of porcelain related to radiation dosimetry

    DEFF Research Database (Denmark)

    Poolton, N.R.J.; Bøtter-Jensen, L.; Jungner, H.

    1995-01-01

    Stokes and anti-Stokes shifted in energy. Glazing is shown in some cases to be considerably more sensitive as a radiation dosemeter than the main porcelain ceramic. By comparison with the properties of artifical phosphors, the principal luminescent matrix is identified as being Al2O3......This article describes the essential features regarding the photo-stimulated luminescence of porcelain: both the main ceramic and glazing materials are studied. In each case, radiation dose dependent signals are observed, superimposed on dose independent luminescence transitions that are both...

  17. Thermal dosimetry studies of ultrasonically induced hyperthermia in normal dog brain and in experimental brain tumors

    International Nuclear Information System (INIS)

    Britt, R.H.; Pounds, D.W.; Stuart, J.S.; Lyons, B.E.; Saxer, E.L.

    1984-01-01

    In a series of 16 acute experiments on pentobarbital anesthetized dogs, thermal distributions generated by ultrasonic heating using a 1 MHz PZT transducer were compared with intensity distributions mapped in a test tank. Relatively flat distributions from 1 to 3 cm have been mapped in normal dog brain using ''shaped'' intensity distributions generated from ultrasonic emission patterns which are formed by the interaction between compressional, transverse and flexural modes activated within the crystal. In contrast, these same intensity distributions generated marked temperature variations in 3 malignant brain tumors presumably due to variations in tumor blood flow. The results of this study suggest that a practical clinical system for uniform heating of large tumor volumes with varying volumes and geometries is not an achievable goal. The author's laboratory is developing a scanning ultrasonic rapid hyperthermia treatment system which will be able to sequentially heat small volume of tumor tissue either to temperatures which will sterilize tumor or to a more conventional thermal dose. Time-temperature studies of threshold for thermal damage in normal dog brain are currently in progress

  18. Personal dosimetry calculations by means of radio pharmacokinetic and gamma graphic studies

    International Nuclear Information System (INIS)

    Arteaga de Murphy, C.; Ferro F, G.; Pedraza L, M.; Montoya M, C.E.

    2000-01-01

    The determination of the absorbed radiation dose is an essential factor to assess the risk to patient with a diagnostic study of nuclear medicine but over all it is indispensable for predicting the efficiency of individualized radio pharmacotherapy and weighting up the risk/benefit of the treatment. In studies for diagnostic or/and treatment of nuclear medicine generally the absorbed radiation dose is not determined for each patient since the methods for estimating it are laborious and include complex models such biological as mathematical, therefore is very important to have a relatively easy method. The obtained data with 99m Tc-Abp., a new radiopharmaceutical for osseous gammagraphy, were used with the purpose of exemplifying a practical method. The radio pharmacokinetic parameters were determined during 24 hours in 10 health voluntaries and serial gamma grams were taken during two hours to another voluntaries. The obtained data were used to estimate, with the MIRDOSE3 computer program, the absorbed radiation dose in an osseous dragging with 99m Tc-Abp. is low: 0.00472 m Gy/MBq to osseous marrow, mainly to the vertebral column and femur, and 0.00169 m Gy/ MBq to whole body. These data are lower than those informed in the medical literature for other bis phosphonates. (Author)

  19. Radiation induced radical in barium sulphate for ESR dosimetry: a preliminary study

    Energy Technology Data Exchange (ETDEWEB)

    Sharaf, M.A.; Hassan, Gamal M. E-mail: gamalhassan65@hotmail.com

    2004-10-01

    Barium sulphate (BaSO{sub 4}) was irradiated by {gamma}-rays and analyzed with electron spin resonance (ESR) to study radiation induced radicals for materials as radiation dosimeter. The ESR spectrum for the radical species is characterized by a hole-type center with g factor of 2.019, 2.0127 and 2.0103 and electron-type center with g factor of 2.0039, 2.0025 and 2.0001. The dosimetric signal with splitting factors of g=2.0039 is ascribed to SO{sub 3}{sup -} radicals and 5G linewidth. The response to {gamma}-ray dose ranging from 5 to 10{sup 3} Gy, energy dependence calculation and the thermal stability have been studied. The number of free radicals per 100 eV (G-value) was obtained to be 0.25 {+-} 0.06 and 0.9 {+-} 0.18 for BaSO{sub 4} and alanine, respectively. The lifetime of radicals and the activation energy were estimated from Arrhenius plots to be approximately 325 {+-} 60 days, and 0.50 {+-} 0.09 eV respectively.

  20. Brachytherapy model with sodium pertechnetate-99mTc balloon (Na99mTcO4-) for breast cancer: evaluation of dosimetry and cell response

    International Nuclear Information System (INIS)

    Lima, Carla Flavia de

    2016-01-01

    Breast cancer is the most common type of cancer that affects more women worldwide. Among various treatment options, radiotherapy which is often used as a treatment for locoregional recurrences control or to decrease tumor size. In patients with breast cancer at an early stage, a booster dose (boost) in the primary tumor area can be applied after conventional radiation therapy. There are several drawbacks to applying this technique. In this work we aimed to perform a dosimetric analysis in a breast model, where it put a balloon filled with sodium pertechnetate- 99m Tc (Na 99m TcO 4 - ) which in future could be used in preference to other possible therapies. The methodology involved the development of dosimetry in water based on radiochromic films and in a computational voxel thorax model. Calibration protocol achieved a mathematical relation between absorbed dose versus optical density (OD) measured at a set of radiochromic sample films placed at the surface of the balloon plus 1 cm up to 10 cm far, in which theoretical dose values were provided by MCNP modeling, reproducing the water equivalent physical simulator. A voxel model of a female thorax, developed at the SISCODES/MCNP codes, received a filled balloon inside. Spatial dose distribution was generated, illustrating the dose received in the chest wall, glandular tissue, breast skin and lung. The dosimetric findings contribute to present the Na 99m TcO 4 - balloon modality which provides a suitable spatial dose distribution in the tumor bed preserving adjacent health tissues. We also studied the radiobiological response radio resistant mammary adenocarcinoma cells (MDAMB231) by exposure of these cells to Na 99m TcO 4 - balloon. The findings include the presence of apoptotic cells in the balloon around point out a favorable response. In conclusion, the balloon may represent a viable option in the supplementary therapy of breast cancer in patients who have appropriate indication. Irradiation with Na 99m TcO 4

  1. Secondary standard dosimetry laboratory (SSDL)

    International Nuclear Information System (INIS)

    Md Saion bin Salikin.

    1983-01-01

    A secondary Standard Dosimetry Laboratory has been established in the Tun Ismail Research Centre, Malaysia as a national laboratory for reference and standardization purposes in the field of radiation dosimetry. This article gives brief accounts on the general information, development of the facility, programmes to be carried out as well as other information on the relevant aspects of the secondary standard dosimetry laboratory. (author)

  2. Anthropometric approaches and their uncertainties to assigning computational phantoms to individual patients in pediatric dosimetry studies

    Science.gov (United States)

    Whalen, Scott; Lee, Choonsik; Williams, Jonathan L.; Bolch, Wesley E.

    2008-01-01

    Current efforts to reconstruct organ doses in children undergoing diagnostic imaging or therapeutic interventions using ionizing radiation typically rely upon the use of reference anthropomorphic computational phantoms coupled to Monte Carlo radiation transport codes. These phantoms are generally matched to individual patients based upon nearest age or sometimes total body mass. In this study, we explore alternative methods of phantom-to-patient matching with the goal of identifying those methods which yield the lowest residual errors in internal organ volumes. Various thoracic and abdominal organs were segmented and organ volumes obtained from chest-abdominal-pelvic (CAP) computed tomography (CT) image sets from 38 pediatric patients ranging in age from 2 months to 15 years. The organs segmented included the skeleton, heart, kidneys, liver, lungs and spleen. For each organ, least-squared regression lines, 95th percentile confidence intervals and 95th percentile prediction intervals were established as a function of patient age, trunk volume, estimated trunk mass, trunk height, and three estimates of the ventral body cavity volume based on trunk height alone, or in combination with circumferential, width and/or breadth measurements in the mid-chest of the patient. When matching phantom to patient based upon age, residual uncertainties in organ volumes ranged from 53% (lungs) to 33% (kidneys), and when trunk mass was used (surrogate for total body mass as we did not have images of patient head, arms or legs), these uncertainties ranged from 56% (spleen) to 32% (liver). When trunk height is used as the matching parameter, residual uncertainties in organ volumes were reduced to between 21 and 29% for all organs except the spleen (40%). In the case of the lungs and skeleton, the two-fold reduction in organ volume uncertainties was seen in moving from patient age to trunk height—a parameter easily measured in the clinic. When ventral body cavity volumes were used

  3. Application of HPLC to the isolation of molecular targets in dosimetry studies

    International Nuclear Information System (INIS)

    Balhorn, R.; Mazrimas, J.A.; Corzett, M.

    1985-01-01

    High-performance liquid chromatography (HPLC) methods are described which permit the rapid isolation of multiple target macromolecules from the tissues of animals exposed to chemical mutagens. DNA and selected chromosomal proteins are isolated in a simple two step separation scheme. The DNA peak is retained for analysis and the chromatin proteins are dialyzed, lyophylized, and rechromatographed on a PRP-1 column to separate individual histones. Using this approach the authors have monitored the kinetics and dose response of adduct formation (and repair) to DNA, histone, hemoglobin and albumin in mice exposed to 7-bromomethylbenzanthracene and benzo[a]pyrene. The results of these studies are described and briefly discussed. Experiments with other mutagens demonstrate the limits to which DNA adduct quantification may be pushed using radioisotopes. Exposures to very high specific activity (200 Ci/mmole) benzo(a)pyrene have allowed DNA adduct quantification down to a few adducts per cell

  4. Study on application of PTFE, FEP and PFA fluoropolymers on radiation dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Galante, A.M.S., E-mail: sgalante@ipen.b [Radiation Metrology Centre, Institute of Energetic and Nuclear Research, IPEN-CNEN/SP, Av. Prof. Lineu Prestes, 2242, Cidade Universitaria, 05508-000 Sao Paulo (Brazil); Galante, O.L. [Borrachas Vipal S/A-Divisao Plasticos, Av. Torres de Oliveira, 329, Bairro Jaguare, 05347-020 Sao Paulo (Brazil); Campos, L.L. [Radiation Metrology Centre, Institute of Energetic and Nuclear Research, IPEN-CNEN/SP, Av. Prof. Lineu Prestes, 2242, Cidade Universitaria, 05508-000 Sao Paulo (Brazil)

    2010-07-21

    Changes induced by radiation in the UV-vis and Infrared absorbance spectra of fluoropolymer films were investigated. Samples (3x1 cm{sup 2}) of commercially available fluoropolymers, tetrafluoropolymer homopolymer (PTFE-Tecnofluor/DuPont) and its copolymers with hexafluoropropylene (FEP 1000 C-DuPont) and perfluoroalkoxy (PFA 500 CLP-Dupont) were irradiated with {sup 60}Co gamma radiation in free air at electronic equilibrium conditions with absorbed doses between 1 and 150 kGy. Studies of environmental condition effects, such as temperature and light, pre- and post-irradiation stability and dose range useful response were carried out. Fluoropolymers are very stable when exposed to different ambient conditions; the dosimetric wavelength is characteristic for each type of fluoropolymer and a linear correlation was found between gamma radiation dose and optical response.

  5. Study of the Melting Latent Heat of Semicrystalline PVDF applied to High Gamma Dose Dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Batista, Adriana S.M. [Departamento de Anatomia e Imagem - IMA, Universidade Federal de Minas Gerais, Av. Prof. Alfredo Balena, 190, 30130-100, Belo Horizonte, MG (Brazil); Gual, Maritza R.; Faria, Luiz O. [Centro de Desenvolvimento da Tecnologia Nuclear - CDTN, Av. Antonio Carlos 6627, C.P. 941, 31270-901, Belo Horizonte, MG (Brazil); Lima, Claubia P.B. [Departamento de Engenharia Nuclear - DEN, Universidade Federal de Minas Gerais - UFMG, Av. Antonio Carlos 6627, 31270-970 Belo Horizonte, MG (Brazil)

    2015-07-01

    Poly(vinylidene fluoride) homopolymers [PVDF] homopolymers were irradiated with gamma doses ranging from 0.5 to 2.75 MGy. Differential scanning calorimetry (DSC) and FTIR spectrometry were used in order to study the effects of gamma radiation in the amorphous and crystalline polymer structures. The FTIR data revealed absorption bands at 1730 and 1853 cm{sup -1} which were attributed to the stretch of C=O bonds, at 1715 and 1754 cm{sup -1} which were attributed to the C=C stretching and at 3518, 3585 and 3673 cm{sup -1} which were associated with NH stretch of NH{sub 2} and OH. The melting latent heat (LM) measured by DSC was used to construct an unambiguous relationship with the delivered dose. Regression analyses revealed that the best mathematical function that fits the experimental calibration curve is a 4-degree polynomial function, with an adjusted Rsquare of 0.99817. (authors)

  6. Evaluation of Multiple-Sampling Function used with a Microtek flatbed scanner for Radiation Dosimetry Calibration of EBT2 Film

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Liyun [Department of Medical Imaging and Radiological Sciences, I-Shou University, Kaohsiung 82445, Taiwan (China); Ho, Sheng-Yow [Department of Nursing, Chang Jung Christian University, Tainan 71101, Taiwan (China); Department of Radiation Oncology, Chi Mei Medical Center, Liouying, Tainan 73657, Taiwan (China); Ding, Hueisch-Jy [Department of Medical Imaging and Radiological Sciences, I-Shou University, Kaohsiung 82445, Taiwan (China); Hwang, Ing-Ming [Department of Medical Imaging and Radiology, Shu Zen College of Medicine and Management, Kaohsiung 82144, Taiwan (China); Chen, Pang-Yu, E-mail: pangyuchen@yahoo.com.tw [Department of Radiation Oncology, Sinlau Christian Hospital, Tainan 70142, Taiwan (China); Lee, Tsair-Fwu, E-mail: tflee@kuas.edu.tw [Medical Physics and Informatics Laboratory, Department of Electronics Engineering, National Kaohsiung University of Applied Sciences, Kaohsiung 80778, Taiwan (China)

    2016-10-01

    The radiochromic EBT2 film is a widely used quality assurance device for radiation therapy. This study evaluated the film calibration performance of the multiple-sampling function, a function of the ScanWizard Pro scanning software provided by the manufacturer, when used with Microtek 9800XL plus (9800XL{sup +}) flatbed scanner. By using the PDD method, each one of the eight EBT2 films, four delivered by 290 monitor unit (MU) and four by 88 MU via 6-MV photon beams, was tightly sandwiched in a 30{sup 3}-cm{sup 3} water equivalent polystyrene phantom prior to irradiation. Before and after irradiation, all films were scanned using the Microtek 9800XL{sup +} scanner with five different modes of the multiple-sampling function, which could generate the image with the averaged result of multiple-sampling. The net optical densities (netOD) on the beam central axis of film were assigned to corresponding depth doses for calibration. For each sampling mode with either delivered MU, the depth-dose uncertainty of a single film from repeated scans and that of a single scan of the four films were analyzed. Finally, the calibration error and the combined calibration uncertainty between film determined depth-doses and delivered depth-doses were calculated and evaluated for each sampling mode. All standard deviations and the calibration error were demonstrated to be unrelated to the number of sampling lines. The calibration error of the 2-line and 16-line mode was within 3 cGy and better than that of the other modes. The combined uncertainty of the 2-line mode was the lowest, which was generally less than 6 cGy except for the delivered dose around 100 cGy. The evaluation described herein revealed that the EBT2 film calibrated with the 2-line mode has relatively lower error, scanning time and combined uncertianty. Therefore, it is recommended for routine EBT2 film calibration and verification of treatment plans.

  7. Radiation chemical dosimetry by means of nitrate-nitrite

    International Nuclear Information System (INIS)

    Tormo Ferrero, M. J.

    1977-01-01

    The different chemical systems used in dosimetry and the selection criteria for them are described. The general topics in dosimetry with alkali nitrates as well as the phenomena occurring in their radiolysis are also treated. The possibility of application in dosimetric areas useful in radiosterilization and industrial processes is studied too. (Author) 22 refs

  8. Field dosimetry on sterilization area of medical-hospitable materials

    International Nuclear Information System (INIS)

    Mariano, C.S.T.P.; Campos, L.L.

    1992-01-01

    The calcium sulfate doped with dysprosium, used in high dose dosimetry by electron paramagnetic resonance (EPR), is studied on field dosimetry for medical-hospitable materials sterilization. The calibration curves of EPR signal in function of absorbed dose in air and the thermal decay of EPR signal at room temperature are also presented. (C.G.C)

  9. Personnel radiation dosimetry symposium: program and abstracts

    International Nuclear Information System (INIS)

    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

  10. Study of radiation effects on some glasses and their applications in radiation dosimetry

    International Nuclear Information System (INIS)

    Mohammad, A.El.

    2008-01-01

    This thesis comprises a study of the X-ray diffraction, thermal, electrical, ESR and optical properties of lead lithium tetra borate glass. The objective of this thesis is to prepare glass dosimeter and study the effect of several gamma-irradiation doses on Lead lithium tetra borate glasses doped with Cu O. The two glasses were prepared from chemical reagents; Li 2 B 4 O 7 from ready package, lead and copper oxide were added in fixed Proportions. The glass melting was made in porcelain crucibles, using electrically heated furnace at temperature of 1000 -1100 degree C. The melts rapidly quenched in air by pressing between two stainless-steel plates mould kept at room temperature. The resultant glasses were colorless for LPTB and transparent greenish sheet of LPTB Cu glass about 0.8 mm thick and where polished to meet the requirements for optical and electrical measurements. The obtained results can be summarized as follows:- Density It is observed that, for unirradiated samples, the addition of copper to LPTB leads to the increase of the number of ions in the sample which decreases the inter-ionic distance. As a result, the molar volume of LPTB Cu decreased and consequently its density increased in the range of 10 ± 1 %. Irradiation with gamma rays is assumed to create displacements, electronic defects and /or breaks in the network bonds. Irradiation can cause the compaction of B 2 O 3 by breaking of the bonds between trigonal elements, allowing the formation of different configuration. Irradiating the LPTB glass with growing gamma doses up to 25 kGy decreased its molar volume with in 4.07 % and consequently increased the density with the same percentage. For the glass LPTB Cu, the effect of gamma rays appeared as a decrease in the molar volume and increase in density with the same percentage (12.9%). The addition traces of copper (0.01 weight %) to LPTB enhanced the effect of gamma radiation on it. Crystallization Behavior: - X-ray diffraction The results show

  11. Preliminary Study on Hybrid Computational Phantom for Radiation Dosimetry Based on Subdivision Surface

    International Nuclear Information System (INIS)

    Jeong, Jong Hwi; Choi, Sang Hyoun; Cho, Sung Koo; Kim, Chan Hyeong

    2007-01-01

    The anthropomorphic computational phantoms are classified into two groups. One group is the stylized phantoms, or MIRD phantoms, which are based on mathematical representations of the anatomical structures. The shapes and positions of the organs and tissues in these phantoms can be adjusted by changing the coefficients of the equations in use. The other group is the voxel phantoms, which are based on tomographic images of a real person such as CT, MR and serially sectioned color slice images from a cadaver. Obviously, the voxel phantoms represent the anatomical structures of a human body much more realistically than the stylized phantoms. A realistic representation of anatomical structure is very important for an accurate calculation of radiation dose in the human body. Consequently, the ICRP recently has decided to use the voxel phantoms for the forthcoming update of the dose conversion coefficients. However, the voxel phantoms also have some limitations: (1) The topology and dimensions of the organs and tissues in a voxel model are extremely difficult to change, and (2) The thin organs, such as oral mucosa and skin, cannot be realistically modeled unless the voxel resolution is prohibitively high. Recently, a new approach has been implemented by several investigators. The investigators converted their voxel phantoms to hybrid computational phantoms based on NURBS (Non-Uniform Rational B-Splines) surface, which is smooth and deformable. It is claimed that these new phantoms have the flexibility of the stylized phantom along with the realistic representations of the anatomical structures. The topology and dimensions of the anatomical structures can be easily changed as necessary. Thin organs can be modeled without affecting computational speed or memory requirement. The hybrid phantoms can be also used for 4-D Monte Carlo simulations. In this preliminary study, the external shape of a voxel phantom (i.e., skin), HDRK-Man, was converted to a hybrid computational

  12. A Dosimetry Study of Deuterium-Deuterium Neutron Generator-based In Vivo Neutron Activation Analysis.

    Science.gov (United States)

    Sowers, Daniel; Liu, Yingzi; Mostafaei, Farshad; Blake, Scott; Nie, Linda H

    2015-12-01

    A neutron irradiation cavity for in vivo neutron activation analysis (IVNAA) to detect manganese, aluminum, and other potentially toxic elements in human hand bone has been designed and its dosimetric specifications measured. The neutron source is a customized deuterium-deuterium neutron generator that produces neutrons at 2.45 MeV by the fusion reaction 2H(d, n)3He at a calculated flux of 7 × 10(8) ± 30% s(-1). A moderator/reflector/shielding [5 cm high density polyethylene (HDPE), 5.3 cm graphite and 5.7 cm borated (HDPE)] assembly has been designed and built to maximize the thermal neutron flux inside the hand irradiation cavity and to reduce the extremity dose and effective dose to the human subject. Lead sheets are used to attenuate bremsstrahlung x rays and activation gammas. A Monte Carlo simulation (MCNP6) was used to model the system and calculate extremity dose. The extremity dose was measured with neutron and photon sensitive film badges and Fuji electronic pocket dosimeters (EPD). The neutron ambient dose outside the shielding was measured by Fuji NSN3, and the photon dose was measured by a Bicron MicroREM scintillator. Neutron extremity dose was calculated to be 32.3 mSv using MCNP6 simulations given a 10-min IVNAA measurement of manganese. Measurements by EPD and film badge indicate hand dose to be 31.7 ± 0.8 mSv for neutrons and 4.2 ± 0.2 mSv for photons for 10 min; whole body effective dose was calculated conservatively to be 0.052 mSv. Experimental values closely match values obtained from MCNP6 simulations. These are acceptable doses to apply the technology for a manganese toxicity study in a human population.

  13. A dosimetry study of deuterium-deuterium neutron generator-based in vivo neutron activation analysis

    Science.gov (United States)

    Sowers, Daniel A.

    A neutron irradiation cavity for in vivo Neutron Activation Analysis (IVNAA) to detect manganese, aluminum, and other potentially toxic elements in human hand bone has been designed and its dosimetric specifications measured. The neutron source is a customized deuterium-deuterium neutron generator which produces neutrons at 2.45 MeV by the fusion reaction 2H(d, n)3He at a calculated flux of 7 x 108 +/-30% s-1. A moderator/reflector/shielding (5 cm high density polyethylene (HDPE), 5.3 cm graphite & 5.7 cm borated HDPE) assembly has been designed and built to maximize the thermal neutron flux inside the hand irradiation cavity and to reduce the extremity dose and effective dose to the human subject. Lead sheets are used to attenuate bremsstrahlung x rays and activation gammas. A Monte Carlo simulation (MCNP6) was used to model the system and calculate extremity dose. The extremity dose was measured with neutron and photon sensitive film badges and Fuji electronic pocket dosimeter (EPD). The neutron ambient dose outside the shielding was measured by Fuji NSN3, and photon dose by a Bicron MicroREM scintillator. Neutron extremity dose was calculated to be 32.3 mSv using MCNP6 simulations given a 10 min IVNAA measurement of manganese. Measurements by EPD and film badge indicate hand dose to be 31.7 +/- 0.8 mSv for neutron and 4.2 +/- 0.2 mSv for photon for 10 mins; whole body effective dose was calculated conservatively to be 0.052 mSv. Experimental values closely match values obtained from MCNP6 simulations. These are acceptable doses to apply the technology for a manganese toxicity study in a human population.

  14. Dosimetry study on the conventional and three dimensional conformal radiation treatment planning protocols for rectal cancer

    International Nuclear Information System (INIS)

    Cai Yong; He Yuxiang; Han Shukui; Wu Hao; Gong Jian; Xu Bo

    2007-01-01

    Objective: To compare the dose distribution of clinical target volume (CTV), in normal tissues and organs for patients with rectal cancer on the conventional radiotherapy (2D) and three dimension- al conformal radiation treatment (3DCRT). Methods: The CT image data of 36 rectal cancer patients treated with 3DCRT were studied. The CTV, small bowel, colon, bladder, pelvic bone marrow, and femoral head and neck were contoured on consecutive axial slices of CT images. Two 3DCRT and three conventional treatment planning protocols were simulated using three dimensional treatment planning system (CMS Focus 2.31), were defined as 3D-3, 3D-4, 2D-2, 2D-3, 2D-4. The difference of five treatment planning protocols on the CTV and normal structure by analysis of dose-volume histograms (DVHs) were compared. Results: The D 95 and V 95 of these five protocols all exceeded 97%. The conformity index(CI) of 3D was obviously larger than that of 2D protocol. The dose inhomogeneity(DI) in 4 DCRT was less than that of 3 DCRT. The 3D as compared with the 2D, significantly reduced the mean dose of 45 Gy to the small bowel and colon. The 3D-3 as compared with the 2D-3, the 3D-4 as compared with the 2D-4, the mean dose of small bowel and colon was reduced by 28.5% and 25.7%, respectively. The 3D-3 as compared with the 2D-2, the 3D-3 as compared with the 2D-3 and the 3D4 as compared with the 2D-4, the percentage volume of small bowel and colon which received 45 Gy was reduced by 80.8% , 51.1% and 54.7% , respectively. Either the mean dose, or the percentage volume receiving 35 Gy and 45 Gy to the pelvic bone and bladder, the 3D planning protocols had advanage over the 2D planning protocols. The V 45 of bladder in 2D-2 planning proto- col was the highest in all planning protocols, exceeding 98%, but the highest V 45 of bladder was only 50% in the other planning protocols. Conclusions: Even though the difference in pelvic CTV of rectal cancer patients between the conventional radiotherapy and 3

  15. Evaluation of radiochromic films EBT3 for in-vivo dosimetry in radiotherapy treatments with photons; Evaluacion de peliculas radiocromicas EBT3 para dosimetria in vivo en tratamientos de radioterapia con fotones

    Energy Technology Data Exchange (ETDEWEB)

    Galvan de la C, O. O.; Rivera M, T. [IPN, Centro de Investigacion en Ciencia Aplicada y Tecnologia Avanzada, Av. Legaria No. 694, Col. Irrigacion, 11500 Mexico D. F. (Mexico); Garcia G, O. A.; Larraga G, J. M., E-mail: olinca@ciencias.unam.mx [Instituto Nacional de Neurologia y Neurocirugia, Laboratorio de Fisica Medica, Insurgentes Sur 3877, Col. La Fama, 14269 Mexico D. F. (Mexico)

    2015-10-15

    Full text: In-vivo dosimetry is a challenge in radiotherapy due to the measures are carried out in reference conditions outside; there is no balance of charged particle and beam consists of photons own and contamination electrons. Detectors that are useful for such measures should be sufficiently small and thin so they do not disturb the beam and do not alter the dose on target. In this paper the radiochromic films Gafchromic model EBT3 are evaluated as potential detectors for in-vivo dosimetry; measurements were carried out in solid water phantom on the surface, with films of dimensions 3 x 3 cm{sup 2}. Irradiations were performed with a linear accelerator Novalis of 6 MV. Comparison between dose values found with a diode type Sfd detector (IBA dosimetry, Germany) and a diamond detector CVD (PTW-Freiburg) for 2 different sized of field (5 x 5 cm{sup 2} and 10 x 10 cm{sup 2}) on the surface of a water phantom scanning was realized. The total spreading factor (Tsf) measured on surface was of 0.831 ± 4.6%; which is greater 12.9% than Tsf measured at a depth of maximum dose. This difference may be due to the contribution of scattered electrons to the beam exit. The measures must be corroborated with Monte Carlo simulations, which they will be validated on surface by the Abdel-Rahman [et al.] method; this mechanism will determine if the films are useful detectors for in-vivo dosimetry clinically. (Author)

  16. Evaluation the implementation of volumetric modulated arc therapy QA in the radiation therapy treatment according to various factors by using the portal dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Kim, So Hyeon; Bae, Sun Myung; Seo, Dong Rin; Kang, Tae Young; Baek, Geum Mun [Dept. of Radiation Oncology, ASAN Medical Center, Seoul (Korea, Republic of)

    2015-12-15

    The pre-treatment QA using Portal dosimetry for Volumetric Arc Therapy To analyze whether maintaining the reproducibility depending on various factors. Test was used for TrueBeam STx{sup TM} (Ver.1.5, Varian, USA). Varian Eclipse Treatment planning system(TPS) was used for planning with total of seven patients include head and neck cancer, lung cancer, prostate cancer, and cervical cancer was established for a Portal dosimetry QA plan. In order to measure these plans, Portal Dosimetry application (Ver.10) (Varian) and Portal Vision aS1000 Imager was used. Each Points of QA was determined by dividing, before and after morning treatment, and the after afternoon treatment ended (after 4 hours). Calibration of EPID(Dark field correction, Flood field correction, Dose normalization) was implemented before Every QA measure points. MLC initialize was implemented after each QA points and QA was retried. Also before QA measurements, Beam Ouput at the each of QA points was measured using the Water Phantom and Ionization chamber(IBA dosimetry, Germany). The mean values of the Gamma pass rate(GPR, 3%, 3mm) for every patients between morning, afternoon and evening was 97.3%, 96.1%, 95.4% and the patient's showing maximum difference was 95.7%, 94.2% 93.7%. The mean value of GPR before and after EPID calibration were 95.94%, 96.01%. The mean value of Beam Output were 100.45%, 100.46%, 100.59% at each QA points. The mean value of GPR before and after MLC initialization were 95.83%, 96.40%. Maintain the reproducibility of the Portal Dosimetry as a VMAT QA tool required management of the various factors that can affect the dosimetry.

  17. Use of data libraries in dosimetry control systems

    International Nuclear Information System (INIS)

    Babenko, V.V.; Babenko, M.I.; Kazimirov, A.S.

    2002-01-01

    Analysis, prediction and planning of dose loads, adequacy in dose management of personnel, evaluation of expediency and sufficiency of existing radiation protection system can be realized with the help of database system of dosimetry control in 'Ukrytie'-shelter

  18. INDIVIDUAL DOSIMETRY SERVICE

    CERN Multimedia

    2000-01-01

    Personnel in the distribution groups Aleph, Delphi, L3, Opal who also work for other experiments than at LEP, should contact their dispatchers to explain their activities for the future, after LEP dismantling in order to be maintained on the regular distribution list at Individual DosimetryWe inform all staff and users under regular dosimetric control that the dosimeters for the monitoring period MAY/JUNE will be available from their usual dispatchers on Tuesday 2 May.Please have your films changed before the 12 May.The colour of the dosimeter valid in is MAY/JUNE is YELLOW.Individual Dosimetry Service will be closed on Friday 28 April.

  19. Collaborative Physical and Biological Dosimetry Studies for Neutron Capture Therapy at the RA-1 Research Reactor Facility

    Energy Technology Data Exchange (ETDEWEB)

    Nigg, D.W.; Schwint, A.E.; Hartwell, J.K.; Heber, E.M.; Trivillin, V.; Castillo, J.; Wentzeis, L.; Sloan, P.; Wemple, C.A.

    2004-10-04

    Initial physical dosimetry measurements have been completed using activation spectrometry and thermoluminiscent dosimeters to characterize the BNCT irradiation facility developed at the RA-1 research reactor operated by the Argentine National Atomic Energy Commission in Buenos Aires. Some biological scoping irradiations have also been completed using a small-animal (hamster) oral mucosa tumor model. Results indicate that the RA-1 neutron source produces useful dose rates but that some improvements in the initial configuration will be needed to optimize the spectrum for thermal-neutron BNCT research applications.

  20. Collaborative Physical and Biological Dosimetry Studies for Neutron Capture Therapy at the RA-1 Research Reactor Facility

    Energy Technology Data Exchange (ETDEWEB)

    David W. Nigg; Amanda E. Schwint; John K. Hartwell; Elisa M. Heber; Veronica Trivillin; Jorge Castillo; Luis Wentzeis; Patrick Sloan; Charles A. Wemple

    2004-10-01

    Initial physical dosimetry measurements have been completed using activation spectrometry and thermoluminiscent dosimeters to characterize the BNCT irradiation facility developed at the RA-1 research reactor operated by the Argentine National Atomic Energy Commission in Buenos Aires. Some biological scoping irradiations have also been completed using a small-animal (hamster) oral mucosa tumor model. Results indicate that the RA-1 neutron source produces useful dose rates but that some improvements in the initial configuration will be needed to optimize the spectrum for thermal-neutron BNCT research applications.

  1. Home Start Evaluation Study.

    Science.gov (United States)

    High/Scope Educational Research Foundation, Ypsilanti, MI.

    Case studies of eight Home Start programs are given as the third section of an evaluation study. Communities involved are Binghamton, New York; Franklin, North Carolina; Cleveland, Ohio; Harrogate, Tennessee; Houston, Texas; Weslaco, Texas; Millville, Utah; Parkersburg, West Virginia. Although each study varies in format, each describes in detail…

  2. 3D MR gel dosimetry with lung equivalent gel; 3D MR-Gel-Dosimetrie mit lungenaequivalentem Gel

    Energy Technology Data Exchange (ETDEWEB)

    Scherer, J.; Solleder, M.; Schiessl, I.; Bogner, L.; Herbst, M. [Klinik und Poliklinik fuer Strahlentherapie und Radioonkologie, Regensburg Univ. (Germany)

    1998-12-31

    The MR gel dosimetry is used to verify complex 3D treatment plans. Till now this method served only for dose evaluation in homogeneous phantoms. On the way to build a heterogeneous anthropomorphic gel phantom, a lung equivalent gel with the density 0.4 g/cm{sup 3} was developed. First experiments show a 1.55 times higher dose reponse in the low density gel (LD gel). The comparison of a dose distribution in a gel/LD gel/gel slab phantom with Monte Carlo calculations shows good agreement within 5%. More over the accuray of the measuring device magnetic resonance imager was studied in respect to the now exclusive digital image processing with the software MRD (MR dosimetry). Because of the dimensions of the Fricke gel phantom an artefact correction, based on the data from the unirradiated phantom proved to be essential. (orig.) [Deutsch] Die MR-Gel-Dosimetrie zur Verifikation komplexer 3D-Bestrahlungsplaene wurde bislang ausschliesslich in homogenen Phantomen durchgefuehrt. Auf dem Wege zum Bau eines inhomogenen Humanoid-Gel-Phantoms wurde ein lungenaequivalentes Gel mit der Dichte 0,4 g/cm{sup 3} entwickelt. Erste Messungen zeigen ein um den Faktor 1,55 hoeheres Ansprechvermoegen in dem low-density-Gel (LD-Gel). Der Vergleich einer gemessen Dosisverteilung in einem Gel/LD-Gel/Gel Schichtphantom als einfaches Thoraxmodell mit Monte-Carlo-Rechnungen zeigt eine gute Uebereinstimmung innerhalb 5%. Ausserdem wurden Untersuchungen zur Messgenauigkeit des Kernspintomographen im Rahmen der nun ausschliesslich digitalen Auswertung mit Hilfe des Programms MRD (MR-Dosimetrie) durchgefuehrt. Es zeigt sich, dass eine Artefaktkorrektur auf der Basis einer Messung des unbestrahlten Phantoms bei grossen Fricke-Gel-Phantomen notwendig ist. (orig.)

  3. SU-E-T-87: A TG-100 Approach for Quality Improvement of Associated Dosimetry Equipment

    Energy Technology Data Exchange (ETDEWEB)

    Manger, R; Pawlicki, T; Kim, G [UCSD Medical Center, La Jolla, CA (United States)

    2015-06-15

    Purpose: Dosimetry protocols devote so much time to the discussion of ionization chamber choice, use and performance that is easy to forget about the importance of the associated dosimetry equipment (ADE) in radiation dosimetry - barometer, thermometer, electrometer, phantoms, triaxial cables, etc. Improper use and inaccuracy of these devices may significantly affect the accuracy of radiation dosimetry. The purpose of this study is to evaluate the risk factors in the monthly output dosimetry procedure and recommend corrective actions using a TG-100 approach. Methods: A failure mode and effects analysis (FMEA) of the monthly linac output check procedure was performed to determine which steps and failure modes carried the greatest risk. In addition, a fault tree analysis (FTA) was performed to expand the initial list of failure modes making sure that none were overlooked. After determining the failure modes with the highest risk priority numbers (RPNs), 11 physicists were asked to score corrective actions based on their ease of implementation and potential impact. The results were aggregated into an impact map to determine the implementable corrective actions. Results: Three of the top five failure modes were related to the thermometer and barometer. The two highest RPN-ranked failure modes were related to barometric pressure inaccuracy due to their high lack-of-detectability scores. Six corrective actions were proposed to address barometric pressure inaccuracy, and the survey results found the following two corrective actions to be implementable: 1) send the barometer for recalibration at a calibration laboratory and 2) check the barometer accuracy against the local airport and correct for elevation. Conclusion: An FMEA on monthly output measurements displayed the importance of ADE for accurate radiation dosimetry. When brainstorming for corrective actions, an impact map is helpful for visualizing the overall impact versus the ease of implementation.

  4. High Throughput PBPK: Evaluating EPA's Open-Source Data and Tools for Dosimetry and Exposure Reconstruction (SOT)

    Science.gov (United States)

    To address this need, new tools have been created for characterizing, simulating, and evaluating chemical biokinetics. Physiologically-based pharmacokinetic (PBPK) models provide estimates of chemical exposures that produce potentially hazardous tissue concentrations, while tissu...

  5. Evaluation of linearity of response and angular dependence of an ionization chamber for dosimetry in computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Perini, Ana P.; Neves, Lucio P.; Xavier, Marcos; Caldas, Linda V.E., E-mail: mxavier@ipen.b, E-mail: lcaldas@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Khoury, Helen J., E-mail: khoury@ufpe.b [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Dept. de Energia Nuclear

    2011-07-01

    In this paper a pencil-type ionization chamber designed and manufactured at Instituto de Pesquisas Energeticas e Nucleares was evaluated for dosimetric applications in computed tomography beams. To evaluate the performance of this chamber two tests were undertaken: linearity of response and angular dependence. The results obtained in these tests showed good results, within the international recommendations. Moreover, this homemade ionization chamber is easy to manufacture, of low cost and efficient. (author)

  6. Standardized physics-dosimetry for US pressure vessel cavity surveillance programs

    International Nuclear Information System (INIS)

    Ruddy, F.H.; McElroy, W.N.; Lippincott, E.P.

    1984-01-01

    Standardized Physics-Dosimetry procedures and data are being developed and tested for monitoring the neutron doses accumulated by reactor pressure vessels (PV) and their support structures. These procedures and data are governed by a set of 21 ASTM standard practices, guides, and methods for the prediction of neutron-induced changes in light water reactor (LWR) PVs and support structure steels throughout the service life of the PV. This paper summarizes the applications of these standards to define the selection and deployment of recommended dosimetry sets, the selection of dosimetry capsules and thermal neutron shields, the placement of dosimetry, the methods of measurement of dosimetry sensor reaction products, data analysis procedures, and uncertainty evaluation procedures. It also describes the validation of these standards both by in-reactor testing of advanced PV cavity surveillance physics-dosimetry and by data development. The use of these standards to guide selection and deployment of advanced dosimetry sets for commercial reactors is also summarized

  7. A prospective study to assess the bladder distension effects on dosimetry in intracavitary brachytherapy of cervical cancer via computed tomography-assisted techniques

    International Nuclear Information System (INIS)

    Sun, L.-M.; Huang, H.-Y.; Huang, E.-Y.; Wang, C.-J.; Ko, S.-F.; Lin Hao; Song, J.-C.

    2005-01-01

    Background and purpose: Intracavitary brachytherapy (ICBT) is as important as external beam radiotherapy (EBRT) for the radical radiotherapy of uterine cervical cancer. The degree of urinary bladder distension during ICBT may affect the dose distribution in the bladder and rectum, to which an overdose may increase the chance of developing treatment-related complications. The purpose of this prospective study was to assess and quantify the impact of bladder distension on dosimetry in ICBT in patients with cervical cancer. Patients and methods: We recruited 20 patients with cervical cancer during a 12-month period. Inclusion criteria included pathological diagnosis of cervical cancer with IA to IIIB stages, and intact uterus. Patients were evaluated for brachytherapy after EBRT, and eligible individuals (cervical os could be identified clearly) were invited enter to this protocol to receive ICBT. In the first brachytherapy, bladder preparation (evacuation and distension by a Foley catheter) and CT scan were performed soon after the insertion of CT-compatible applicators. Then the bladder wall doses [median dose, maximum dose and dose-volume histograms (DVH)] were calculated via the PLATO computer planning system (Nucletron PLATO-RTS version 2.0). The individual data regarding doses and DVH were collected and compared. Bladder distension may shift the applicator position, and posterior displacement of the applicator system may increase the dose to the rectal wall, so this effect was also evaluated. Results: All the continuous variables of these 20 patients followed a normal distribution. By paired t-test and multiple linear regression analysis, we found that bladder distension statistically significantly decreased the median bladder wall dose with an average reduction of 48% of the dose of an empty bladder (P<0.001), and the maximum dose did not change; on the other hand, the bladder distension did not have any adverse effects on the rectal wall doses. Conclusions

  8. Status of radiation processing dosimetry

    DEFF Research Database (Denmark)

    Miller, A.

    1993-01-01

    Several milestones have marked the field of radiation processing dosimetry since IMRP 7. Among them are the IAEA symposium on High Dose Dosimetry for Radiation Processing and the international Workshops on Dosimetry for Radiation Processing organized by the ASTM. Several standards have been...... or are being published by the ASTM in this field, both on dosimetry procedures and on the proper use of specific dosimeter systems. Several individuals are involved in this international cooperation which contribute significantly to the broader understanding of the role of dosimetry in radiation processing....... The importance of dosimetry is emphasized in the standards on radiation sterilization which are currently drafted by the European standards organization CEN and by the international standards organization ISO. In both standards, dosimetry plays key roles in characterization of the facility, in qualification...

  9. Review on individual neutron dosimetry

    International Nuclear Information System (INIS)

    Portal, M.

    1983-01-01

    Up to now, nuclear energy workers in relation to neutron radiations were few. Fast development of nuclear energy lead us to study, for future, individual dosimetry techniques which are autonomous, more accurate and cheaper. The future dosemeter will be a couple: fast neutron dosemeter and slow neutron dosemeter. The different current studies concerning this ''composite'' dosemeter are described. In 1984-1985, operation of a ''non-homogeneous, composite'' dosemeter is foreseen; later on, an ''homogeneous composite'' dosemeter that is to say a dosemeter which needs same basis techniques [fr

  10. Gafchromic EBT2 film dosimetry in reflection mode with a novel plan-based calibration method.

    Science.gov (United States)

    Mendez, I; Hartman, V; Hudej, R; Strojnik, A; Casar, B

    2013-01-01

    A dosimetric system formed by Gafchromic EBT2 radiochromic film and Epson Expression 10000XL flatbed scanner was commissioned for dosimetry. In this paper, several open questions concerning the commissioning of radiochromic films for dosimetry were addressed: (a) is it possible to employ this dosimetric system in reflection mode; (b) if so, can the methods used in transmission mode also be used in reflection mode; (c) is it possible to obtain accurate absolute dose measurements with Gafchromic EBT2 films; (d) which calibration method should be followed; (e) which calibration models should be used; and (f) does three-color channel dosimetry offer a significant improvement over single channel dosimetry. The purpose of this paper is to help clarify these questions. In this study, films were scanned in reflection mode, the effect of surrounding film was evaluated and the feasibility of EBT2 film dosimetry in reflection mode was studied. EBT2's response homogeneity has been reported to lead to excessive dose uncertainties. To overcome this problem, a new plan-based calibration method was implemented. Plan-based calibration can use every pixel and each of the three color channels of the scanned film to obtain the parameters of the calibration model. A model selection analysis was conducted to select lateral correction and sensitometric curve models. The commonly used calibration with fragments was compared with red-channel plan-based calibration and with three-channel plan-based calibration. No effect of surrounding film was found in this study. The film response inhomogeneity in EBT2 films was found to be important not only due to differences in the fog but also due to differences in sensitivity. The best results for lateral corrections were obtained using absolute corrections independent of the dose. With respect to the sensitometric curves, an empirical polynomial fit of order 4 was found to obtain results equivalent to a gamma-distributed single hit model based on

  11. Dose Estimation from Daily and Weekly Dosimetry Data

    Energy Technology Data Exchange (ETDEWEB)

    Ostrouchov, G.

    2001-11-16

    Statistical analyses of data from epidemiologic studies of workers exposed to radiation have been based on recorded annual radiation doses (yearly dose of record). It is usually assumed that the dose values are known exactly, although it is generally recognized that the data contain uncertainty due to measurement error and bias. In our previous work with weekly data, a probability distribution was used to describe an individual's dose during a specific period of time and statistical methods were developed for estimating it from weekly film dosimetry data. This study showed that the yearly dose of record systematically underestimates doses for Oak Ridge National Laboratory (ORNL) workers. This could result in biased estimates of dose-response coefficients and their standard errors. The results of this evaluation raise serious questions about the suitability of the yearly dose of record for direct use in low-dose studies of nuclear industry workers. Here, we extend our previous work to use full information in Pocket meter data and develop the Data Synthesis for Individual Dose Estimation (DSIDE) methodology. Although the DSIDE methodology in this study is developed in the context of daily and weekly data to produce a cumulative yearly dose estimate, in principle it is completely general and can be extended to other time period and measurement combinations. The new methodology takes into account the ''measurement error'' that is produced by the film and pocket-meter dosimetry systems, the biases introduced by policies that lead to recording left-censored doses as zeros, and other measurement and recording practices. The DSIDE method is applied to a sample of dose histories obtained from hard copy dosimetry records at ORNL for the years 1945 to 1955. First, the rigorous addition of daily pocket-meter information shows that the negative bias is generally more severe than was reported in our work based on weekly film data only, however, the

  12. Chernobyl Experience in the Field of Retrospective Dosimetry

    International Nuclear Information System (INIS)

    Chumak, V.; Bakhanova, E.

    2011-01-01

    most cases, particular needs called for development of new techniques and approaches. These approaches were quite different, yet all were aimed at reconstruction of individual doses to the subjects exposed after Chernobyl accident and paid special attention to assessment of associated uncertainties. The dose estimates were used for evaluation of impact of the accident on evacuated population and residents of contaminated areas downwind Chernobyl as well as for analytical epidemiological studies and estimation of risk factors. Although these tasks constituted a challenge, most of the aims were achieved and now dose reconstruction approaches and techniques were brought to new qualitative level. Though each dose reconstruction effort is unique and is determined by the needs of a particular study, the accumulated experience could be applied for broad variety of retrospective and emergency dosimetry applications. (author)

  13. MATLAB platform for Monte Carlo planning and dosimetry experimental evaluation; Plataforma Matlab para planificacion Monte Carlo y evaluacion dosimetrica experimental

    Energy Technology Data Exchange (ETDEWEB)

    Baeza, J. A.; Ureba, A.; Jimenez-Ortega, E.; Pereira-Barbeiro, A. R.; Leal, A.

    2013-07-01

    A new platform for the full Monte Carlo planning and an independent experimental evaluation that it can be integrated into clinical practice. The tool has proved its usefulness and efficiency and now forms part of the flow of work of our research group, the tool used for the generation of results, which are to be suitably revised and are being published. This software is an effort of integration of numerous algorithms of image processing, along with planning optimization algorithms, allowing the process of MCTP planning from a single interface. In addition, becomes a flexible and accurate tool for the evaluation of experimental dosimetric data for the quality control of actual treatments. (Author)

  14. Dosimetry of low-energy beta radiation

    International Nuclear Information System (INIS)

    Borg, J.

    1996-08-01

    Useful techniques and procedures for determination of absorbed doses from exposure in a low-energy β radiation field were studied and evaluated in this project. The four different techniques included were β spectrometry, extrapolation chamber dosimetry, Monte Carlo (MC) calculations, and exoelectron dosimetry. As a typical low-energy β radiation field a moderated spectrum from a 14 C source (E β , max =156 keV) was chosen for the study. The measured response of a Si(Li) detector to photons (bremsstrahlung) showed fine agreement with the MC calculated photon response, whereas the difference between measured and MC calculated responses to electrons indicates an additional dead layer thickness of about 12 μm in the Si(Li) detector. The depth-dose profiles measured with extrapolation chambers at two laboratories agreed very well, and it was confirmed that the fitting procedure previously reported for 147 Pm depth-dose profiles is also suitable for β radiation from 14 C. An increasing difference between measured and MC calculated dose rates for increasing absorber thickness was found, which is explained by limitations of the EGS4 code for transport of very low-energy electrons (below 10-20 keV). Finally a study of the thermally stimulated exoelectron emission (TSEE) response of BeO thin film dosemeters to β radiation for radiation fields with maximum β energies ranging from 67 keV to 2.27 MeV is reported. For maximum β energies below approximately 500 keV, a decrease in the response amounting to about 20% was observed. It is thus concluded that a β dose higher than about 10 μGy can be measured with these dosemeters to within 0 to -20% independently of the βenergy for E β , max values down to 67 keV. (au) 12 tabs., 38 ills., 71 refs

  15. Glucinium dosimetry in beryl

    International Nuclear Information System (INIS)

    Kremer, M.

    1949-05-01

    The application of the method developed by Kolthoff and Sandell (1928) for the dosimetry of glucinium (beryllium) in beryl gives non-reproducible results with up to 20% discrepancies. This method recommends to separate beryllium and aluminium using 8 hydroxyquinoline and then to directly precipitate glucinium in the filtrate using ammonia. One possible reason of the problems generated by this method should be the formation of a volatile complex between beryllium and the oxine. This work shows that when the oxine is eliminated before the precipitation with ammonia the dosimetry of beryllium becomes accurate. The destruction of the oxine requires the dry evaporation of the filtrate, which is a long process. Thus the search for a reagent allowing the quantitative precipitation of beryllium in its solutions and in presence of oxine has been made. It has been verified also that the quantitative precipitation of the double beryllium and ammonium phosphate is not disturbed by the oxine in acetic buffer. This method, which gives good results, has also the advantage to separate beryllium from the alkaline-earth compounds still present in the filtrate. The report details the operation mode of the method: beryllium dosimetry using ammonium phosphate, aluminium-beryllium separation, application to beryl dosimetry (ore processing, insolubilization of silica, precipitation with ammonia, precipitation with oxine, precipitation of PO 4 NH 4 Gl, preciseness). (J.S.)

  16. Group: radiation dosimetry

    International Nuclear Information System (INIS)

    Caldas, L.V.E.

    1990-01-01

    The main activities of the radiation dosimetry group is described, including the calibration of instruments, sources and radioactive solutions and the determination of neutron flux; development, production and market dosimetric materials; development radiation sensor make the control of radiation dose received by IPEN workers; development new techniques for monitoring, etc. (C.G.C.)

  17. Solid state radiation dosimetry

    International Nuclear Information System (INIS)

    Moran, P.R.

    1976-01-01

    Important recent developments provide accurate, sensitive, and reliable radiation measurements by using solid state radiation dosimetry methods. A review of the basic phenomena, devices, practical limitations, and categories of solid state methods is presented. The primary focus is upon the general physics underlying radiation measurements with solid state devices

  18. INDIVIDUAL DOSIMETRY SERVICE

    CERN Multimedia

    2002-01-01

    Deadline...Deadline...Deadline...Deadline...Deadline...Deadline...   Individual dosimetry service We inform all staffs and users under regular dosimetric control that the dosimeters for the monitoring period JANUARY/FEBRUARY 2002 are available from their usual dispatchers. Please have your films changed before the 15th of January. The color of the dosimeter valid in JANUARY/FEBRUARY is WHITE.

  19. High frequency electromagnetic dosimetry

    CERN Document Server

    Sánchez-Hernández, David A

    2009-01-01

    Along with the growth of RF and microwave technology applications, there is a mounting concern about the possible adverse effects over human health from electromagnetic radiation. Addressing this issue and putting it into perspective, this groundbreaking resource provides critical details on the latest advances in high frequency electromagnetic dosimetry.

  20. Dosimetry of pion beams

    International Nuclear Information System (INIS)

    Dicello, J.F.

    1975-01-01

    Negative pion beams are probably the most esoteric and most complicated type of radiation which has been suggested for use in clinical radiotherapy. Because of the limited availability of pion beams in the past, even to nuclear physicists, there exist relatively fewer basic data for this modality. Pion dosimetry is discussed

  1. Individual dosimetry service

    CERN Document Server

    2004-01-01

    We inform all staff and users under regular dosimetry control that the dosimeters for the monitoring period JULY-AUGUST 2004 are available from their usual dispatchers. Please have your films changed before the 15 JULY 2004. The color of the dosimeter valid in July-August 2004 is PINK.

  2. Application of gel dosimetry - A preliminary study on verification of uniformity of activity and length of source used in Beta-Cath system

    International Nuclear Information System (INIS)

    Subramaniam, S.; Rabi Raja Singh, I.; Visalatchi, S.; Paul Ravindran, B.

    2002-01-01

    Recently the intraluminal irradiation of coronary arteries following balloon angioplasty is found to reduce proliferation of smooth muscle cells and restenosis. Among the isotopes used for the intracoronary irradiation, 90 Sr/Y appears to be ideal (H I Almos et al, 1996). In 1984 Gore et al proposed that radiation induced changes in the well-established Fricke solution could be probed with Nuclear Magnetic Resonance (NMR) relaxation measurements rather than using conventional spectrophotometry measurements. This was a major step in the development of gel dosimetry and since then gel dosimetry has been one of the major advances in the dosimetry of complex radiation fields has been in the area of gel dosimetry. In this preliminary work on gel dosimetry we present the verification of uniformity of activity along the length of the source train and verification of the length of the source used in the Beta-Cath system used for intracoronary brachytherapy with ferrous gel dosimeter. The Beta-Cath system obtained from Novoste, Norcross, GA was used in this study. It consists of a source train of 16 90 Sr/Y sources each of length 2.5mm. The total length of the source train is 40mm. For preparation of the Ferrous-Gelatin Gel, the recipe provided by the London Regional Cancer Center, London Ontario, Canada was used. Stock solutions of 50mM H 2 SO 4 , 0.3 mM ferrous ammonium sulphate, 0.05mM Xylenol orange was first prepared. The gel was prepared by mixing 4% gelatin with distilled water while stirring in a water bath at 40-42 deg. C. Acid solution, Ferrous ammonium sulphate solution and Xylenol orange were added and stirred in the water bath for about an hour to allow aeration. The mixture was poured in to three 20ml syringes to form the gel and stored in the refrigerator at 5 deg. C. For irradiation with Beta-Cath, the gel was prepared in three cylindrical 20ml syringes. A nylon tube having the same dimension as that of the delivery catheter used in intra-coronary was placed

  3. Exposure to mobile telecommunication networks assessed using personal dosimetry and well-being in children and adolescents: the German MobilEe-study.

    Science.gov (United States)

    Thomas, Silke; Kühnlein, Anja; Heinrich, Sabine; Praml, Georg; von Kries, Rüdiger; Radon, Katja

    2008-11-04

    Despite the increase of mobile phone use in the last decade and the growing concern whether mobile telecommunication networks adversely affect health and well-being, only few studies have been published that focussed on children and adolescents. Especially children and adolescents are important in the discussion of adverse health effects because of their possibly higher vulnerability to radio frequency electromagnetic fields. We investigated a possible association between exposure to mobile telecommunication networks and well-being in children and adolescents using personal dosimetry. A population-based sample of 1.498 children and 1.524 adolescents was assembled for the study (response 52%). Participants were randomly selected from the population registries of four Bavarian (South of Germany) cities and towns with different population sizes. During a Computer Assisted Personal Interview data on participants' well-being, socio-demographic characteristics and potential confounder were collected. Acute symptoms were assessed three times during the study day (morning, noon, evening).Using a dosimeter (ESM-140 Maschek Electronics), we obtained an exposure profile over 24 hours for three mobile phone frequency ranges (measurement interval 1 second, limit of determination 0.05 V/m) for each of the participants. Exposure levels over waking hours were summed up and expressed as mean percentage of the ICNIRP (International Commission on Non-Ionizing Radiation Protection) reference level. In comparison to non-participants, parents and adolescents with a higher level of education who possessed a mobile phone and were interested in the topic of possible adverse health effects caused by mobile telecommunication network frequencies were more willing to participate in the study. The median exposure to radio frequency electromagnetic fields of children and adolescents was 0.18% and 0.19% of the ICNIRP reference level respectively. In comparison to previous studies this is one of

  4. Exposure to mobile telecommunication networks assessed using personal dosimetry and well-being in children and adolescents: the German MobilEe-study

    Directory of Open Access Journals (Sweden)

    von Kries Rüdiger

    2008-11-01

    Full Text Available Abstract Background Despite the increase of mobile phone use in the last decade and the growing concern whether mobile telecommunication networks adversely affect health and well-being, only few studies have been published that focussed on children and adolescents. Especially children and adolescents are important in the discussion of adverse health effects because of their possibly higher vulnerability to radio frequency electromagnetic fields. Methods We investigated a possible association between exposure to mobile telecommunication networks and well-being in children and adolescents using personal dosimetry. A population-based sample of 1.498 children and 1.524 adolescents was assembled for the study (response 52%. Participants were randomly selected from the population registries of four Bavarian (South of Germany cities and towns with different population sizes. During a Computer Assisted Personal Interview data on participants' well-being, socio-demographic characteristics and potential confounder were collected. Acute symptoms were assessed three times during the study day (morning, noon, evening. Using a dosimeter (ESM-140 Maschek Electronics, we obtained an exposure profile over 24 hours for three mobile phone frequency ranges (measurement interval 1 second, limit of determination 0.05 V/m for each of the participants. Exposure levels over waking hours were summed up and expressed as mean percentage of the ICNIRP (International Commission on Non-Ionizing Radiation Protection reference level. Results In comparison to non-participants, parents and adolescents with a higher level of education who possessed a mobile phone and were interested in the topic of possible adverse health effects caused by mobile telecommunication network frequencies were more willing to participate in the study. The median exposure to radio frequency electromagnetic fields of children and adolescents was 0.18% and 0.19% of the ICNIRP reference level respectively

  5. Dosimetric evaluation of the Fricke gel dosimeter using the spectrophotometric technique for application in electron and neutron dosimetry; Avaliacao dosimetrica da solucao Fricke gel usando a tecnica de espectrofotometria para aplicacao na dosimetria de eletrons e neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Mangueira, Thyago Fressatti [Instituto de Pesquisas Energeticas e Nucleares (GMR/IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Centro de Metrologia das Radiacoes

    2011-07-01

    The main dosimetric characteristics of the Fricke Xylenol Gel (FXG) solution were established for further application in the measurement of dose distribution of clinical electron fields. The dose-response curves of the FXG in a thermal neutron field were also evaluated for application in Boron Neutron Capture Therapy (BNCT) and industrial electron fields. The standard reading technique was the spectrophotometry. For clinical fields the intra and inter-batch reproducibility of FXG solution are better than 1.4% and 5.1%, respectively. The optical response presents a linear behavior for doses ranging from 0.2 to 40 Gy independently of the electron energy and the dose rate in the studied ranges. Due to the effects of the FXG natural oxidation, the optimum elapsed time between FXG preparation and irradiation was established as 24h. The behavior of the dose-response curve does not change the obtained absorbance values relative to the non-irradiated dosimeter response during the studied period. The dose-response curve to industrial electron beam presented an exponential decreasing behavior. The optical response to thermal neutrons beam presented a linear behavior for the studied dose range. According to the obtained results to the different radiation fields studied it was not observed changes in the wavelength of the typical bands of the absorption spectrum radiation induced. Additional tests were performed with FXG solution to verify the viability and application of FXG dosimetry on intracavitary brachytherapy using digital photographic imaging. The excellent performance of the FXG dosimeter indicates that this dosimeter may be applied to tri-dimensional dose evaluation in radiotherapy treatments using electrons and neutron beams. (author)

  6. Dosimetric evaluation of the Fricke gel dosimeter using the spectrophotometric technique for application in electron and neutron dosimetry; Avaliacao dosimetrica da solucao Fricke gel usando a tecnica de espectrofotometria para aplicacao na dosimentria de eletrons e neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Mangueira, Thyago Fressatti

    2009-07-01

    In this work the main dosimetric characteristics of the Fricke Xylenol Gel (FXG) solution were established for further application in the measurement of dose distribution of clinical electron fields. The dose-response curves of the FXG in a neutron field were also evaluated for the research in Boron Neutron Capture Therapy (BNCT) and industrial electron fields. The standard reading technique was the spectrophotometric. For the clinical field, the intra and inter-batch reproducibility are better than 1.4% and 5.1 %, respectively, the response presents a linear behavior for doses ranging from 0.2 to 40 Gy independently of the energy and the dose rate in the studied ranges. Due to the effects of the FXG natural oxidation, the optimum elapsed time between FXG preparation and irradiation was established as 24h period and the behavior of the dose-response curve of the FXG using the variation in the absorbance relative to the non-irradiated dosimeter as a basis during the whole studied period were not altered. The dose-response to the industrial electron beam presented an exponential decreasing behavior and the neutron beam for research in BNCT presented a linear behavior for the complete studied dose range. According to the obtained results for the different types of radiation studied for the FXG, there was no change in the position of the characteristic bands of the absorption spectrum due to the interaction of these radiation types. Additional tests were performed to determine the digital photographic imaging of FXG analyses viability and the application of FXG dosimetry on intracavitary brachytherapy. The good performance of the FXG dosimeter in the tests that were carried out indicates that this dosimeter may be applied to the tri-dimensional dose evaluation in radiotherapic treatments using electrons and neutron beams. (author)

  7. Implicit dosimetry of microorganism photodynamic inactivation

    Science.gov (United States)

    Tamošiūnas, Mindaugas; Kuliešienė, Neringa; Daugelavičius, Rimantas

    2017-12-01

    Photosensitization based antibacterial treatment is efficient against a broad range of pathogens but it utilizes suboptimal dosimetry with an explicit (and very broad range) determination of sensitizer concentration, light dose and fluence rates. In this study we verified the implicit dosimetry approach for pathogen photodynamic treatment, employing protoporphyrin IX (ppIX) photobleaching to assess the killing efficacy against Staphylococcus aureus and Candida albicans cells. The results show that there was an increased kill of S. aureus and C. albicans at higher degree of ppIX fluorescence decay. Therefore ppIX photobleaching can be incorporated into the PDI dose metric offering to predict the pathogen killing efficacy during photodynamic treatment.

  8. Performance testing of dosimetry processors, status of NRC rulemaking for improved personnel dosimetry processing, and some beta dosimetry and instrumentation problems observed by NRC regional inspectors

    International Nuclear Information System (INIS)

    Dennis, N.A.; Kinneman, J.D.; Costello, F.M.; White, J.R.; Nimitz, R.L.

    1983-01-01

    Early dosimetry processor performance studies conducted between 1967 and 1979 by several different investigators indicated that a significant percentage of personnel dosimetry processors may not be performing with a reasonable degree of accuracy. Results of voluntary performance testing of US personnel dosimetry processors against the final Health Physics Society Standard, Criteria for Testing Personnel Dosimetry Performance by the University of Michigan for the Nuclear Regulatory Commission (NRC) will be summarized with emphasis on processor performance in radiation categories involving beta particles and beta particles and photon mixtures. The current status of the NRC's regulatory program for improved personnel dosimetry processing will be reviewed. The NRC is proposing amendments to its regulations, 10 CFR Part 20, that would require its licensees to utilize specified personnel dosimetry services from processors accredited by the National Voluntary Laboratory Accreditation Program of the National Bureau of Standards. Details of the development and schedule for implementation of the program will be highlighted. Finally, selected beta dosimetry and beta instrumentation problems observed by NRC Regional Staff during inspections of NRC licensed facilities will be discussed

  9. Personal Dosimetry Enhancement for Underground Workplaces

    Directory of Open Access Journals (Sweden)

    L. Thinová

    2005-01-01

    Full Text Available Personal dosimetry for underground workers mainly concerns measurement of the concentration of radon (and its daughters and the correct application of the data in dose calculation, using a biokinetic model for lung dosimetry. A conservative approach for estimating the potential dose in caves (or underground is based on solid state alpha track detector measurements. The obtained dataset is converted into an annual effective dose in agreement with the ICRP recommendations using the “cave factor”, the value of which depends on the spectrum of aerosol particles, or on the proportional representation of the unattached and the attached fraction and on the equilibrium factor. The main difference between apartments and caves is the absence of aerosol sources, high humidity, low ventilation rate and the uneven surface in caves. A more precisely determined dose value would have a significant impact on radon remedies or on restricting the time workers stay underground. In order to determine  how the effective dose is calculated, it is necessary to divide these areas into distinct categories by the following measuring procedures: continual radon measurement (to capture the differences in EERC between working hours and night-time, and also between daily and seasonal radon concentration variations; regular measurements of radon and its daughters to estimate the equilibrium factor and the presence of 218Po; regular indoor air flow measurements to study the location of the radon supply and its transfer among individual areas of the cave; natural radioactive element content evaluation in subsoils and in water inside/outside, a study of the radon sources in the cave; aerosol particle-size spectrum measurements to determine the free fraction; monitoring the behaviour of guides and workers to record the actual time spent in the cave, in relation to the continuously monitored levels of Rn concentration. 

  10. Latest developments in silica fibre luminescence dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Bradley, D. A.; Abdul S, S. F.; Jafari, S. M.; Alanazi, A. [University of Surrey, Department of Physics, GU2 7XH Guildford, Surrey (United Kingdom); Amouzad M, G. [University of Malaya, Faculty of Engineering, Department of Electrical Engineering, Integrated Lightwave Research Group, 50603 Kuala Lumpur (Malaysia); Addul R, H. A.; Mizanur R, A. K. M.; Zubair, H. T.; Begum, M.; Yusoff, Z.; Omar, N. Y. M. [Multimedia University, Faculty of Engineering, 2010 Cyberjaya, Selangor (Malaysia); Maah, M. J. [University of Malaya, Department of Chemistry, 50603 Kuala Lumpur (Malaysia); Collin, S. [National Physical Laboratory, Hampton Road, Teddington, TW11 OLW Middlesex (United Kingdom); Mat-Sharif, K. A.; Muhd-Yassin, S. Z.; Zulkifli, M. I., E-mail: d.a.bradley@surrey.ac.uk [Telekom Malaysia Research and Development Sdn Bhd., 63000 Cyberjaya, Selangor (Malaysia)

    2015-10-15

    Full text: Using tailor made sub-mm diameter doped-silica fibres, we are carrying out luminescence dosimetry studies for a range of situations, including thermoluminescence (Tl)investigations on a liquid alpha source formed of {sup 223}RaCl (the basis of the Bayer Health care product Xofigo), the Tl response to a 62 MeV proton source and Tl response to irradiation from an {sup 241}Am-Be neutron source. In regard to the former, in accord with the intrinsic high linear energy transfer (Let) and short path length (<100 um) of the α-particles in calcified tissue, the product is in part intended as a bone-seeking radionuclide for treatment of metastatic cancer, offering high specificity and efficacy. The Tl yield of Ge-doped SiO{sub 2} fibres has been investigated including for photonic crystal fibre un collapsed, flat fibres and single mode fibres, these systems offering many advantages over conventional passive dosimetry types. In particular, one can mention comparable and even superior sensitivity, an effective atomic number Z{sub eff} of the silica dosimetric material close to that of bone, and the glassy nature of the fibres offering the additional advantage of being able to place such dosimeters directly into liquid environments. Finally we review the use of our tailor made fibres for on-line radioluminescence measurements of radiotherapy beams. The outcome from these various lines of research is expected to inform development of doped fiber radiation dosimeters of versatile utility, ranging from clinical applications through to industrial studies and environmental evaluations. (Author)

  11. Historical Evaluation of Film Badge Dosimetry Y-12 Plant: Part 2–Neutron Radiation ORAUT-OTIB-0045

    Energy Technology Data Exchange (ETDEWEB)

    Kerr GD, Frome EL, Watkins JP, Tankersley WG

    2009-12-14

    A summary of the major neutron sources involved in radiation exposures to Y-12 workers is presented in this TIB. Graphical methods are used to evaluate available neutron dose data from quarterly exposures to Y-12 workers and to determine how the data could be used to derive neutron-to-gamma dose ratios for dose reconstruction purposes. This TIB provides estimates of neutron-to-gamma dose ratios for specific departments and a default value for the neutron-to-gamma dose ratio based on the pooled neutron dose data for all Y-12 departments.

  12. Radiation Dosimetry Study of [89Zr]rituximab Tracer for Clinical Translation of B cell NHL Imaging using Positron Emission Tomography

    Science.gov (United States)

    Natarajan, Arutselvan; Gambhir, Sanjiv Sam

    2015-01-01

    Purpose We evaluated the dosimetry of [89Zr]rituximab, an anti-CD20 immunoPET tracer to image B cell non-Hodgkin’s lymphoma (NHL) using a humanized transgenic mouse model that expresses human CD20 transgenic mice (huCD20TM). Procedures Rituximab was conjugated to desferrioxamine (Df) for radiolabeling of Zirconium-89. [89Zr]rituximab (2.8±0.2 MBq) was tail vein-injected into huCD20T mice. Positron emission tomography (PET)/CT imaging was performed on the two groups of mice (blocking=2 mg/kg pre-dose of rituximab and non-blocking; n=5) at eight time points (1, 4, 24, 48, 72, 96, 120, and 168 h) post injection. Results The novel [89Zr]rituximab PET tracer had good immunoreactivity, was stable in human serum, and was able to specifically target human CD20 in mice. The human equivalents of highest dose (mean±SD) organs with and without pre-dose are liver (345±284 μSv/MBq) and spleen (1165±149 μSv/MBq), respectively. Conclusions Dosimetry of the human patient whole-body dose was found to be 145 MBq per annum, and the patient dose-limiting organ will be the liver (with rituximab pre-dose blocking) and spleen for non-blocking. The [89Zr]rituximab (t½=78.4 h) imaging of B cell NHL patients could permit the observation of targeting lesions in NHL patients over an extended period due to longer half-life as compared to the [64Cu] rituximab (t½=12.7 h). PMID:25500766

  13. Initial investigation of a novel light-scattering gel phantom for evaluation of optical CT scanners for radiotherapy gel dosimetry

    International Nuclear Information System (INIS)

    Bosi, Stephen; Naseri, Pourandokht; Puran, Alicia; Davies, Justin; Baldock, Clive

    2007-01-01

    There is a need for stable gel materials for phantoms used to validate optical computerized tomography (CT) scanners used in conjunction with radiation-induced polymerizing gel dosimeters. Phantoms based on addition of light-absorbing dyes to gelatine to simulate gel dosimeters have been employed. However, to more accurately simulate polymerizing gels one requires phantoms that employ light-scattering colloidal suspensions added to the gel. In this paper, we present the initial results of using an optical CT scanner to evaluate a novel phantom in which radiation-exposed polymer gels are simulated by the addition of colloidal suspensions of varying turbidity. The phantom may be useful as a calibration transfer standard for polymer gel dosimeters. The tests reveal some phenomena peculiar to light-scattering gels that need to be taken into account when calibrating polymer gel dosimeters

  14. Evaluation of GAFCHROMIC EBT2 dosimetry for the low dose range using a flat-bed scanner with the reflection mode

    International Nuclear Information System (INIS)

    Gotanda, Tatsuhiro; Katsuda, Toshizo; Akagawa, Takuya; Gotanda, Rumi; Tabuchi, Akihiko; Yamamoto, Kenyu; Kuwano, Tadao; Takedo, Yoshihiro; Yatake, Hidetoshi; Yabunaka, Koichi

    2013-01-01

    Recently developed radiochromic films can easily be used to measure absorbed doses because they do not need development processing and indicate a density change that depends on the absorbed dose. However, in GAFCHROMIC EBT2 dosimetry (GAF-EBT2) as a radiochromic film, the precision of the measurement was compromised, because of non-uniformity problems caused by image acquisition using a flat-bed scanner with a transmission mode. The purpose of this study was to improve the precision of the measurement using a flat-bed scanner with a reflection mode at the low absorbed dose dynamic range of GAF-EBT2. The calibration curves of the absorbed dose versus the film density for GAF-EBT2 were provided. X-rays were exposed in the range between ~0 and 120 mGy in increments of about 12 mGy. The results of the method using a flat-bed scanner with the transmission mode were compared with those of the method using the same scanner with the reflection mode. The results should that the determination coefficients (r 2 ) for the straight-line approximation of the calibration curve using the reflection mode were higher than 0.99, and the gradient using the reflection mode was about twice that of the one using the transmission mode. The non-uniformity error that is produced by a flat-bed scanner with the transmission mode setting could be almost eliminated by converting from the transmission mode to the reflection mode. In light of these findings, the method using a flat-bed scanner with the reflection mode (only using uniform white paper) improved the precision of the measurement for the low absorbed dose range.

  15. Evaluation of epidemiological studies

    International Nuclear Information System (INIS)

    Breckow, J.

    1995-01-01

    The publication is intended for readers with a professional background in radiation protection who are not experts in the field of epidemiology. The potentials and the limits of epidemiology are shown and concepts and terminology of radioepidemilogic studies as well as epidemiology in general are explained, in order to provide the necessary basis for understanding or performing evaluations of epidemiologic studies. (orig./VHE) [de

  16. Development of radiation biological dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Chul Koo; Kim, Tae Hwan; Lee, Yun Sil; Son, Young Sook; Kim, Soo Kwan; Jang, Won Suk; Le, Sun Joo; Jee, Young Heun; Jung, Woo Jung

    1999-04-01

    Up until now, only a few methods have been developed for radiation biological dosimetry such as conventional chromosome aberration and micronucleus in peripheral blood cell. However, because these methods not only can be estimated by the expert, but also have a little limitation due to need high technique and many times in the case of radiation accident, it is very difficult to evaluate the absorbed dose of victims. Therefore, we should develop effective, easy, simple and rapid biodosimetry and its guideline (triage) to be able to be treated the victims as fast as possible. We established the premature chromosome condensation assay and apoptotic fragment assay which was the significant relationship between dose and cell damages to evaluate the irradiation dose as correct and rapid as possible using lymphocytes and crypt cells, and compared with conventional chromosome aberration assay and micronuclei assay.

  17. Technical guidelines for personnel dosimetry calibrations

    International Nuclear Information System (INIS)

    Roberson, P.L.; Fox, R.A.; Hadley, R.T.; Holbrook, K.L.; Hooker, C.D.; McDonald, J.C.

    1983-01-01

    A base of technical information has been acquire and used to evaluate the calibration, design, and performance of selected personnel systems in use at Department of Energy (DOE) facilites. A technical document was prepared to guide DOE and DOE contractors in selecting and evaluating personnel dosimetry systems and calibration. A parallel effort was initiated to intercompare the adiological calibrations standards used to calibrate DOE personnel dosimeters

  18. Retrospective dosimetry of populations exposed to reactor accident: Chernobyl example, lesson for Fukushima

    International Nuclear Information System (INIS)

    Chumak, Vadim V.

    2013-01-01

    Follow-up of the Chernobyl accident had included a good deal of retrospective dosimetry and dose reconstruction. Comparison of Chernobyl and Fukushima shows that despite some differences in course and scale of the two accidents, main elements are present in both situations and Chernobyl experience could be quite educative for better understanding and more optimal handling of Fukushima Dai-ichi accident consequences. This paper contains review of dose reconstruction efforts done to date and extensively published in scientific journals and reports. Specifically the following cases are considered: (i) evaluation of individual doses to evacuees; (ii) validation of ecological dosimetric models and ruling out unconfirmed dose rate measurements; dosimetric support of (iii) case–control study of leukemia among Chernobyl clean-up workers (liquidators), and (iv) cohort study of cataracts among liquidators. Due to limited size of this paper the given application cases are rather outlined while more detailed descriptions could be found in relevant publications. Each considered Chernobyl case is commented with respect to possible application to Fukushima Dai-ichi situation. The presented methodological findings and approaches could be used for retrospective assessment of human exposures in Fukushima. -- Highlights: ► Retrospective dosimetry in Chernobyl was applied for evaluation of individual doses to evacuees. ► Retrospective dosimetry in Chernobyl was applied for validation of ecological dosimetric models, rejection dubious dose rate records. ► Retrospective dosimetry in Chernobyl was applied for risk assessment of leukemia among Chernobyl clean-up workers (liquidators). ► Retrospective dosimetry in Chernobyl was applied for study of cataracts among liquidators. ► Experience of dose reconstruction in Chernobyl could be used for retrospective assessment of exposures in Fukushima

  19. Quantities and concepts used in radiation dosimetry

    International Nuclear Information System (INIS)

    Carlsson, G.A.; Carlsson, C.A.

    1982-01-01

    Radiation dosimetry is a pure physical science, as fostered by the elegant work of the International Commission on Radiation Units and Measurements (ICRU), in defining the basic quantities and units of dosimetry. Nevertheless, questions concerning the interpretation and application of some quantities still remain. The present work focuses on some of these questions and in particular deals with the quantity fluence which is frequently misunderstood. Radiation dosimetry is closely related to radiation transport theory, and the usefulness of the vectorial quantities used extensively in transport theory is pointed out. It is proposed that vectorial quantities be included in the radiometry considerations of the ICRU. This would contribute to clarifying the basic concepts of dosimetry and promoting its establishment as a physical science. Equations are given for calculating the absorbed dose in various conditions of radiation equilibrium, along with discussions of the quantities needed for their evaluations. These equations are relevant to the important field of cavity theory. Refinements of existing cavity theories, in particular those for photon and electron irradiations, can benefit from a deeper understanding of these equations and the various conditions of equilibrium in which they are valid. (author)

  20. Verification of the pure alanine in PMMA tube dosimeter applicability for dosimetry of radiotherapy photon beams: a feasibility study.

    Science.gov (United States)

    Al-Karmi, Anan M; Ayaz, Ali Asghar H; Al-Enezi, Mamdouh S; Abdel-Rahman, Wamied; Dwaikat, Nidal

    2015-09-01

    Alanine dosimeters in the form of pure alanine powder in PMMA plastic tubes were investigated for dosimetry in a clinical application. Electron paramagnetic resonance (EPR) spectroscopy was used to measure absorbed radiation doses by detection of signals from radicals generated in irradiated alanine. The measurements were performed for low-dose ranges typical for single-fraction doses often used in external photon beam radiotherapy. First, the dosimeters were irradiated in a solid water phantom to establish calibration curves in the dose range from 0.3 to 3 Gy for 6 and 18 MV X-ray beams from a clinical linear accelerator. Next, the dosimeters were placed at various locations in an anthropomorphic pelvic phantom to measure the dose delivery of a conventional four-field box technique treatment plan to the pelvis. Finally, the doses measured with alanine dosimeters were compared against the doses calculated with a commercial treatment planning system (TPS). The results showed that the alanine dosimeters have a highly sensitive dose response with good linearity and no energy dependence in the dose range and photon beams used in this work. Also, a fairly good agreement was found between the in-phantom dose measurements with alanine dosimeters and the TPS dose calculations. The mean value of the ratios of measured to calculated dose values was found to be near unity. The measured points in the in-field region passed dose-difference acceptance criterion of 3% and those in the penumbral region passed distance-to-agreement acceptance criterion of 3 mm. These findings suggest that the pure alanine powder in PMMA tube dosimeter is a suitable option for dosimetry of radiotherapy photon beams.

  1. A comparative study on patient specific absolute dosimetry using slab phantom, acrylic body phantom and goat head phantom

    Directory of Open Access Journals (Sweden)

    Om Prakash Gurjar

    2015-01-01

    Full Text Available Purpose: To compare the results of patient specific absolute dosimetry using slab phantom, acrylic body phantom and goat head phantom. Methods: Fifteen intensity modulated radiotherapy (IMRT plans already planned on treatment planning system (TPS for head-and-neck cancer patients were exported on all three kinds of phantoms viz. slab phantom, acrylic body phantom and goat head phantom, and dose was calculated using anisotropic analytic algorithm (AAA. All the gantry angles were set to zero in case of slab phantom while set to as it is in actual plan in case of other two phantoms. All the plans were delivered by linear accelerator (LA and dose for each plan was measured by 0.13 cc ion chamber. The percentage (% variations between planned and measured doses were calculated and analyzed. Results: The mean % variations between planned and measured doses of all IMRT quality assurance (QA plans were as 0.65 (Standard deviation (SD: 0.38 with confidence limit (CL 1.39, 1.16 (SD: 0.61 with CL 2.36 and 2.40 (SD: 0.86 with CL 4.09 for slab phantom, acrylic head phantom and goat head phantom respectively. Conclusion: Higher dose variations found in case of real tissue phantom compare to results in case of slab and acrylic body phantoms. The algorithm AAA does not calculate doses in heterogeneous medium as accurate as it calculates in homogeneous medium. Therefore the patient specific absolute dosimetry should be done using heterogeneous phantom mimicking density wise as well as design wise to the actual human body.  

  2. Dosimetry for food irradiation

    International Nuclear Information System (INIS)

    2002-01-01

    A Manual of Food Irradiation Dosimetry was published in 1977 under the auspices of the IAEA as Technical Reports Series No. 178. It was the first monograph of its kind and served as a reference in the field of radiation processing and in the development of standards. While the essential information about radiation dosimetry in this publication has not become obsolete, other publications on radiation dosimetry have become available which have provided useful information for incorporation in this updated version. There is already a Codex General Standard for Irradiated Foods and an associated Code of Practice for Operation of Irradiation Facilities used for Treatment of Food, issued in 1984 by the Codex Alimentarius Commission of the FAO/WHO Food Standard Programme. The Codex Standard contains provisions on irradiation facilities and process control which include, among other requirements, that control of the processes within facilities shall include the keeping of adequate records including quantitative dosimetry. Appendix A of the Standard provides an explanation of process control and dosimetric requirements in compliance with the Codex Standard. By 1999, over 40 countries had implemented national regulations or issued specific approval for certain irradiated food items/classes of food based on the principles of the Codex Standard and its Code of Practice. Food irradiation is thus expanding, as over 30 countries are now actually applying this process for the treatment of one or more food products for commercial purposes. Irradiated foods are being marketed at retail level in several countries. With the increasing recognition and application of irradiation as a sanitary and phytosanitary treatment of food based on the provisions of the Agreement on the Application of Sanitary and Phytosanitary Measures of the World Trade Organization, international trade in irradiated food is expected to expand during the next decade. It is therefore essential that proper dosimetry

  3. Evaluation of singlet oxygen explicit dosimetry for predicting treatment outcomes of benzoporphyrin derivative monoacid ring A-mediated photodynamic therapy

    Science.gov (United States)

    Kim, Michele M.; Penjweini, Rozhin; Zhu, Timothy C.

    2017-02-01

    Existing dosimetric quantities do not fully account for the dynamic interactions between the key components of photodynamic therapy (PDT) or the varying PDT oxygen consumption rates for different fluence rates. Using a macroscopic model, reacted singlet oxygen ([) was calculated and evaluated for its effectiveness as a dosimetric metric for PDT outcome. Mice bearing radiation-induced fibrosarcoma tumors were treated with benzoporphyrin derivative monoacid ring A (BPD) at a drug-light interval of 3 h with various in-air fluences (30 to 350 J/cm2) and in-air fluence rates (50 to 150 mW/cm2). Explicit measurements of BPD concentration and tissue optical properties were performed and used to calculate [, photobleaching ratio, and PDT dose. For four mice, in situ measurements of O23 and BPD concentration were monitored in real time and used to validate the in-vivo photochemical parameters. Changes in tumor volume following treatment were used to determine the cure index, CI=1-k/kctr, where k and kctr are the tumor regrowth rates with PDT and without PDT, respectively. The correlation between CI and the dose metrics showed that the calculated [ at 3 mm is an effective dosimetric quantity for predicting treatment outcome and a clinically relevant tumor regrowth endpoint.

  4. Scientific days on electromagnetic fields: from dosimetry to human health - Conference proceedings; Journees scientifiques - Champs electromagnetiques: de la dosimetrie a la sante humaine - Recueil des resumes et presentations

    Energy Technology Data Exchange (ETDEWEB)

    Wiart, J.; Ghanmi, A.; Picon, O.; Conil, E.; Varsier, N.; Hadjem, A.; Sudret, B.; Magne, I.; Souques, M.; Gaudaire, F.; De Seze, R.; Jawad, O.; Lautru, D.; Dricot, J.M.; Horlin, F.; De Doncker, P.; Drissaoui, A.; Musy, F.; Nicolas, L.; Perrussel, R.; Scorretti, R.; Voyer, D.; Jala, M.; Moulines, E.; Levy-Leduc, C.; Mahfouz, Z.; Gati, A.; Fouad Hanna, V.; Leveque, P.; Arnaud-Cormos, D.; Zhadobov, M.; Jarrige, P.; Gaborit, G.; Kohler, S.; Ticaud, N.; Duvillaret, L.; Guelilia, Z.; Loison, R.; Gillard, R.; Laisne, A.; Favet, D.; Benadhira, R.; Mir, L.; Nadi, M.; Kourtiche, D.; Gazeau, F.; Wilhelm, C.; Delemotte, L.; Breton, M.; Tarek, M.; Marc-Vergnes, J.P.; Yardin, C.; Perrin, A.; Le Drean, Y.; Sauleau, R.; Lambrozo, J.; Selmaoui, B.; Ghosn, R.; Thuroczy, G.; Villegier, A.S.; Loos, N.; Brenet-Dufour, V.; Liabeuf, S.; Bach, V.; Moretti, D.; Lewis, N.; Garenne, A.; Poulletier De Gannes, F.; Haro, E.; Lagroye, I.; Bornat, Y.; Boutaib, Y.; Saighi, S.; Renaud, S.; Veyre, B.; Schuz, J.; Deltour, I.; Van Deventer, E.; Vecchia, P.; Merckel, O.; Bellaouel, A.; Demaret, P.; Donati, P.; Jovanovic, D.; Chauvin, S.; Desreumaux, J.P.; Fouquet, L.; Picard, D.; Massardier-Pilonchery, A.; Hours, M.; Bergeret, A.; Person, C.; Toutain, Y.; Butet, R.; Berrahma, K.; Balderelli, I.; Stelmaszyk, V.; Cretallaz, C.; Lamproglou, I.; Amourette, C.; Diserbo, M.; Fauquette, W.; Martigne, P.; Collin, A.; Lagroye, I.; Ait Aissa, S.; Hurtier, A.; Taxile, M.; Le Montagner, L.; Athane, A.; Duleu, S.; Percherancier, Y.; Geffard, M.; Ruffie, G.; Billaudel, B.; Veyret, B.; Pelletier, A.; Delanaud, S.; Libert, J.P.; Schunck, T.; Bieth, F.; Soubere Mahamoud, Y.; Le Quement, C.; Ferrand, G.; Le Guevel, R.; Carton, P.H.; Luong, M.; Tanvir, S.; Selmaoui, B.; Silva Pires-Antonietti, V.; Sonnet, P.; Pulvin, S.; Kuster, O.; Tetelin, C.

    2012-04-15

    This document brings together the available presentations (articles and slides) given at the URSI scientific days on electromagnetic fields: dosimetry, peoples' exposure, biological and health risks, risk management, and medical uses. 48 presentations are compiled in this document and deal with: 1 - Stochastic dosimetry: variability challenge; 2 - How to estimate the exposure to 50/60 Hz magnetic field in an epidemiological study?; 3 - Joint analysis of population exposure and radio coverage of GSM and UMTS mobile phone networks; 4 - Study of the specific energy absorption rate (SAR) sensitiveness to phone positions near the head for 2 GSM mobile phones; 5 - Statistical Study of SAR under Wireless Channel - Exposure in Indoor Environment; 6 - Uncertainty propagation in numerical dosimetry: how to reduce calculation costs?; 7 - Use of a simplified pregnant woman model for foetus exposure analysis; 8 - SAR estimation using multi-exposure with a mobile phone; 9 - State-of-the-art in experimental dosimetry (RF and pulses); 10 - Mm-waves dosimetry: issues, stakes and actual solutions; 11 - Use of DG-FDTD for a dosimetry calculation in a strongly multi-scale problem: determination of the eye-SAR near a HF/VHF vehicle-borne source; 12 - Dosimetric measurements with a fiber-type electro-optical sensor; 13 - Partial experimental evaluation of basic restrictions in the HF/VHF range; 14 - Repetitive trans-cranial magnetic stimulation Stimulation (rTMS) in psychiatry: present day situation and perspectives; 15 - Medical applications of electric fields; 16 - Measurements for life: new perspectives? 17 - Nano-particles and magnetic stimuli for medical imaging and therapy; 18 - Molecular Insights into electroporation and siRNA electro-transfer through model cell membranes; 19 - State of knowledge on electromagnetic fields hypersensitivity (HS-CEM); 20 - Experimentation methodology: from results to interpretation; 22 - Mm waves - update on biological effects at 40-60 GHz; 23

  5. Thermoluminescence dosimetry of rare earth doped calcium ...

    Indian Academy of Sciences (India)

    Unknown

    CaAl2O4) doped with different rare earth ions have been studied and their suitability for radiation dosimetry applications is discussed. It is observed that monocalcium aluminate doped with cerium is a good dosimeter having linear response up to ...

  6. Thermoluminescence dosimetry of rare earth doped calcium ...

    Indian Academy of Sciences (India)

    The thermoluminescence (TL) properties of calcium aluminate (CaAl2O4) doped with different rare earth ions have been studied and their suitability for radiation dosimetry applications is discussed. It is observed that monocalcium aluminate doped with cerium is a good dosimeter having linear response up to about 4 kGy of ...

  7. Safeguards and Physics Measurements: Neutron Dosimetry

    International Nuclear Information System (INIS)

    Vanhavere, F.

    2000-01-01

    The objective of SCK-CEN's R and D programme on neutron dosimetry is to improve the determination of neutron doses by studying neutron spectra, neutron dosemeters and shielding adaptations as well as to investigate the charcteristics of bubble detectors in order to be able to use them as direct-readiong neutron dosemeters

  8. Modern methods of personnel dosimetry

    International Nuclear Information System (INIS)

    Kraus, W.; Herrmann, D.; Kiesewetter, W.

    The physical properties of radiation detectors for personnel dosimetry are described and compared. The suitability of different types of dosimeters for operational and central monitoring of normal occupational exposure, for accident and catastrophe dosimetry and for background and space-flight dosimetry is discussed. The difficulties in interpreting the dosimeter reading with respect to the dose in individual body organs are discussed briefly. 430 literature citations (up to Spring 1966) are given

  9. The dosimetry of ionizing radiation

    CERN Document Server

    1990-01-01

    A continuation of the treatise The Dosimetry of Ionizing Radiation, Volume III builds upon the foundations of Volumes I and II and the tradition of the preceeding treatise Radiation Dosimetry. Volume III contains three comprehensive chapters on the applications of radiation dosimetry in particular research and medical settings, a chapter on unique and useful detectors, and two chapters on Monte Carlo techniques and their applications.

  10. Statistical study of the activity developed in the Unit of Environmental Dosimetry and Personnel of the Radioprotection Service of the National Center of Environmental Health

    International Nuclear Information System (INIS)

    Ruiz Gimeno, G.; Moracho, J.; Sánchez, L.; Ballesteros, G.; Medina, P.; Castro, J.

    2016-01-01

    The service of radiation protection of the National Center for Environmental Health, which belongs to the Institute of Health Carlos III, began its activities in the 80’s. This study shows the dosimetry data of professionals working in the fields of health, research and/ or education, and the industry in radioactive installations controlled by the unit between 1992 and 2013. This work presents the different kinds of dosimeter and the evolution of the number of controlled people in the diverse activity fields during these 22 years, the trend of the average annual doses and the highest received doses, as well as the effect of the administrative doses. Finally a summary of the conclusions from these data is presented. [es

  11. Biological dosimetry of irradiation accidents; La dosimetrie biologique des accidents d`irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Durand, V.; Chambrette, V.; Le Roy, A.; Paillole, N.; Sorokine, I.; Voisin, P.

    1994-12-31

    The biological dosimetry in radiation protection allows to evaluate the received dose by a potentially irradiated person from biological markers such chromosomal abnormalities. The technologies of Hybridization In Situ by Fluorescence (F.I.S.H) allow the detection of steady chromosomal aberrations of translocation type.

  12. Interlaboratory niobium dosimetry comparison

    International Nuclear Information System (INIS)

    Wille, P.

    1980-01-01

    For an interlaboratory comparison of neutron dosimetry using niobium the 93 sup(m)Nb activities of irradiated niobium monitors were measured. This work was performed to compare the applied techniques of dosimetry with Nb in different laboratories. The niobium monitors were irradiated in the fast breeder EBRII, USA and the BR2, Belgium. The monitors were dissolved and several samples were prepared. Their niobium contents were determined by the 94 Nb-count rates. since the original specific count rate was known. The KX radiations of the 93 sup(m)Nb of the samples and of a calibrated Nb-foil were compared. This foil was measured by PTB, Braunschweig and CBNM, Geel, which we additionally compared with the KX radiation of 88 Sr produced by a thin 88 Y source from a 88 Y-standard solution (PTB). (orig.) [de

  13. Sixth symposium on neutron dosimetry

    International Nuclear Information System (INIS)

    1987-01-01

    This booklet contains all abstracts of papers presented in 13 sessions. Main topics: Cross sections and Kerma factors; analytical radiobiology; detectors for personnel monitoring; secondary charged particles and microdosimetric basis of q-value for neutrons; personnel dosimetry; concepts for radiation protection; ambient monitoring; TEPC and ion chambers in radiation protection; beam dosimetry; track detectors (CR-39); dosimetry at biomedical irradiation facilities; health physics at therapy facilities; calibration for radiation protection; devices for beam dosimetry (TLD and miscellaneous); therapy and biomedical irradiation facilities; treatment planning. (HP)

  14. Effect of different breathing patterns in the same patient on stereotactic ablative body radiotherapy dosimetry for primary renal cell carcinoma: A case study

    International Nuclear Information System (INIS)

    Pham, Daniel; Kron, Tomas; Foroudi, Farshad; Siva, Shankar

    2013-01-01

    Stereotactic ablative body radiotherapy (SABR) for primary renal cell carcinoma (RCC) targets requires motion management strategies to verify dose delivery. This case study highlights the effect of a change in patient breathing amplitude on the dosimetry to organs at risk and target structures. A 73-year-old male patient was planned for receiving 26 Gy of radiation in 1 fraction of SABR for a left primary RCC. The patient was simulated with four-dimensional computed tomography (4DCT) and the tumor internal target volume (ITV) was delineated using the 4DCT maximum intensity projection. However, the initially planned treatment was abandoned at the radiation oncologist's discretion after pretreatment cone-beam CT (CBCT) motion verification identified a greater than 50% reduction in superior to inferior diaphragm motion as compared with the planning 4DCT. This patient was resimulated with respiratory coaching instructions. To assess the effect of the change in breathing on the dosimetry to the target, each plan was recalculated on the data set representing the change in breathing condition. A change from smaller to larger breathing showed a 46% loss in planning target volume (PTV) coverage, whereas a change from larger breathing to smaller breathing resulted in an 8% decrease in PTV coverage. ITV coverage was similarly reduced by 8% in both scenarios. This case study highlights the importance of tools to verify breathing motion prior to treatment delivery. 4D image guided radiation therapy verification strategies should focus on not only verifying ITV margin coverage but also the effect on the surrounding organs at risk

  15. Comparison of organ dosimetry methods and effective dose calculation methods for paediatric CT.

    Science.gov (United States)

    Brady, Z; Cain, T M; Johnston, P N

    2012-06-01

    Computed tomography (CT) is the single biggest ionising radiation risk from anthropogenic exposure. Reducing unnecessary carcinogenic risks from this source requires the determination of organ and tissue absorbed doses to estimate detrimental stochastic effects. In addition, effective dose can be used to assess comparative risk between exposure situations and facilitate dose reduction through optimisation. Children are at the highest risk from radiation induced carcinogenesis and therefore dosimetry for paediatric CT recipients is essential in addressing the ionising radiation health risks of CT scanning. However, there is no well-defined method in the clinical environment for routinely and reliably performing paediatric CT organ dosimetry and there are numerous methods utilised for estimating paediatric CT effective dose. Therefore, in this study, eleven computational methods for organ dosimetry and/or effective dose calculation were investigated and compared with absorbed doses measured using thermoluminescent dosemeters placed in a physical anthropomorphic phantom representing a 10 year old child. Three common clinical paediatric CT protocols including brain, chest and abdomen/pelvis examinations were evaluated. Overall, computed absorbed doses to organs and tissues fully and directly irradiated demonstrated better agreement (within approximately 50 %) with the measured absorbed doses than absorbed doses to distributed organs or to those located on the periphery of the scan volume, which showed up to a 15-fold dose variation. The disparities predominantly arose from differences in the phantoms used. While the ability to estimate CT dose is essential for risk assessment and radiation protection, identifying a simple, practical dosimetry method remains challenging.

  16. Complete Biological Evaluation of Therapeutical Radiopharmaceuticals in Rodents, Laboratory Beagles and Veterinary Patients - Preclinical Distribution-, Kinetic-, Excretion-, Internal Dosimetry-, Radiotoxicological-, Radiation Safety- and Efficacy Data

    International Nuclear Information System (INIS)

    Balogh, L.; Domokos, M.; Polyak, A.; Thuroczy, J.; Janoki, G.

    2009-01-01

    The research and development of various novel therapeutical radiopharmaceuticals is a huge demand in many laboratories world-wide. Beside of multiple bone metastases pain-palliation and radiosynovectomy agents a number of specific radiopharmaceutical applicants mainly for oncological applications are in the pipeline. Numerous in vitro methods are available in the first line to test the radiolabelling efficiency, the possible radioactive and non-labelled impurities, the stability of the label at different conditions and mediums, and some specific characteristics of radiopharmaceutical applicants eg.: receptor binding assays, antigen-antibody assays. But, still before human clinical trials there are several questions to be solved in regards of toxicology, radiotoxicology, radiation safety and maybe most importantly the efficacy tasks. All these issues cannot be answered without animal tests. Several decades back animal tests in radiopharmacy meant only standard bioassays in a large number of healthy rodents. Later on pathological models eg.: human tumor xenografts in immunodeficient animals came-out and through them radiopharmaceutical tumor-uptake by the targets were available to evaluate in vivo as well. Xenografts are still popular and widely used models in the field but instead of wide-scaled bioassays nowadays repeated scintiscans or hybrid images (SPECT/CT, PET/CT) are more and more often used to answer kinetic-, excretion-, tumor uptake, internal dosimetry (Minimum Effective Dose, Maximum Tolerable Dose, critical organ doses, tumor doses) questions. Greater animals like laboratory Beagles are more closely in size, clinical and metabolic parameters to the human objects so playing a more perfect role of human medical doctor and especially veterinary patients. Easy to understand that many of the spontaneously occurring companion animal diseases are a good model of human pathological diseases. The need of a better diagnosis and treatment of that animals meets with

  17. Personnel radiation dosimetry

    International Nuclear Information System (INIS)

    1987-01-01

    The book contains the 21 technical papers presented at the Technical Committee Meeting to Elaborate Procedures and Data for the Intercomparison of Personnel Dosimeters organizaed by the IAEA on 22-26 April 1985. A separate abstract was prepared for each of these papers. A list of areas in which additional research and development work is needed and recommendations for an IAEA-sponsored intercomparison program on personnel dosimetry is also included

  18. Dosimetry for Crystals Irradiation

    CERN Document Server

    Lecomte, Pierre

    2005-01-01

    Before shipment to CMS, all PbWO4 crystals produced in China are irradiated there with 60 Co , in order to insure that the induced absorption coefficient is within specifications. Acceptance tests at CERNand at ENEA also include irradiation with gamma rays from 60 Co sources. There were initially discrepancies in quoted doses and doserates as well as in induced absorption coefficients. The present work resolves the discrepancies in irradiation measurements and defines common dosimetry methods for consistency checks between irradiation facilities.

  19. Dosimetry: an ARDENT topic

    CERN Multimedia

    CERN Bulletin

    2012-01-01

    The first annual ARDENT workshop took place in Vienna from 20 to 23 November. The workshop gathered together the Early-Stage Researchers (ESR) and their supervisors, plus other people involved from all the participating institutions.   “The meeting, which was organised with the local support of the Austrian Institute of Technology, was a nice opportunity for the ESRs to get together, meet each other, and present their research plans and some preliminary results of their work,” says Marco Silari, a member of CERN Radiation Protection Group and the scientist in charge of the programme. Two full days were devoted to a training course on radiation dosimetry, delivered by renowned experts. The workshop closed with a half-day visit to the MedAustron facility in Wiener Neustadt. ARDENT (Advanced Radiation Dosimetry European Network Training) is a Marie Curie ITN project funded under EU FP7 with €4 million. The project focuses on radiation dosimetry exploiting se...

  20. Dosimetry in life sciences

    International Nuclear Information System (INIS)

    1975-01-01

    The uses of radiation in medicine and biology have grown in scope and diversity to make the Radiological Sciences a significant factor in both research and medical practice. Of critical importance in the applications and development of biomedical and radiological techniques is the precision with which the dose may be determined at all points of interest in the absorbing medium. This has developed as a result of efficacy of investigations in clinical radiation therapy, concern for patient safety and diagnostic accuracy in diagnostic radiology and the advent of clinical trials and research into the use of heavily ionizing radiations in biology and medicine. Since the last IAEA Symposium on Dosimetry Techniques applied to Agriculture, Industry, Biology and Medicine, held in Vienna in 1972, it has become increasingly clear that advances in the techniques and hardware of biomedical dosimetry have been rapid. It is for these reasons that this symposium was organized in a concerted effort to focus on the problems, developments and areas of further research in dosimetry in the Life Sciences. (author)

  1. AN EXACT GOODNESS-OF-FIT TEST BASED ON THE OCCUPANCY PROBLEMS TO STUDY ZERO-INFLATION AND ZERO-DEFLATION IN BIOLOGICAL DOSIMETRY DATA.

    Science.gov (United States)

    Fernández-Fontelo, Amanda; Puig, Pedro; Ainsbury, Elizabeth A; Higueras, Manuel

    2018-01-12

    The goal in biological dosimetry is to estimate the dose of radiation that a suspected irradiated individual has received. For that, the analysis of aberrations (most commonly dicentric chromosome aberrations) in scored cells is performed and dose response calibration curves are built. In whole body irradiation (WBI) with X- and gamma-rays, the number of aberrations in samples is properly described by the Poisson distribution, although in partial body irradiation (PBI) the excess of zeros provided by the non-irradiated cells leads, for instance, to the Zero-Inflated Poisson distribution. Different methods are used to analyse the dosimetry data taking into account the distribution of the sample. In order to test the Poisson distribution against the Zero-Inflated Poisson distribution, several asymptotic and exact methods have been proposed which are focused on the dispersion of the data. In this work, we suggest an exact test for the Poisson distribution focused on the zero-inflation of the data developed by Rao and Chakravarti (Some small sample tests of significance for a Poisson distribution. Biometrics 1956; 12 : 264-82.), derived from the problems of occupancy. An approximation based on the standard Normal distribution is proposed in those cases where the computation of the exact test can be tedious. A Monte Carlo Simulation study was performed in order to estimate empirical confidence levels and powers of the exact test and other tests proposed in the literature. Different examples of applications based on in vitro data and also data recorded in several radiation accidents are presented and discussed. A Shiny application which computes the exact test and other interesting goodness-of-fit tests for the Poisson distribution is presented in order to provide them to all interested researchers. © The Author(s) 2018. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    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.

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

    International Nuclear Information System (INIS)

    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

  4. Research on the experimental verification of dosimetry calculations. Progress report

    International Nuclear Information System (INIS)

    Poston, J.W.

    1983-04-01

    This research has been directed toward the development of experimental techniques for the evaluation of internal-dosimetry calculations. There have been three major objectives. The first was the development and refinement of dosimetric techniques necessary to obtain absorbed doses averaged over the entire volume of particular organs. Other major objectives have included the utilization of these dosimetry systems to measure absorbed doses in anthropomorphic phantoms, and the comparison of these experimental results to absorbed dose estimates obtained from Monte Carlo computer calculations. At the present time, only limited data are available for direct comparison. However, more data should be available soon and comparisons will be made before the end of the present contract period. This proposal outlines the current status of our research toward that end. In addition, it is proposed that this contract be renewed to continue investigations into other aspects of dosimetry, for example, dosimetry for the survivors of the bombings of Hiroshima and Nagasaki

  5. Recommendations about criticality accident dosimetry

    International Nuclear Information System (INIS)

    1975-07-01

    The aims of criticality accident dosimetry and the characteristics peculiar to a critical burst being defined, the requirements to be fulfilled by a dosimetric system applied to this type of measurements are presented. The devices chosen by the C.E.A. Radiation Survey Divisions, simple and cheap, are described along with the main processes to be carried out in order to evaluate doses after an accident. The apparatus necessary for detector counting and the directions for use are presented in detail, allowing standardization of measurements. A set of linear formula enables to obtain, from these measurements, all required informations about neutron fluences and spectra, along with the suitable components of the dose at the irradiated people locations [fr

  6. Radiation dosimetry for radionuclide therapy

    International Nuclear Information System (INIS)

    Kim, Eun Hee

    2001-01-01

    The radionuclide therapy is a protocol for tumor control by administering radionuclides as the cytotoxic agents. Radionuclides concentrated at the site of cancerous lesion are expected to kill the cancerous cells with minimal injury to the normal tissue. The efficacy of every radionuclide treatment can be evaluated by examining the toxicity to the lesion differentiated from that to the normal tissue. Radiation dosimerty is the procedure of quantitating the energy absorbed by target volumes of interest. Dosimetric information plays an indicator of the expected radiation damage and thus the therapeutic efficacy. This paper summarizes the dosimetric aspects in radionuclide therapy in terms of radionuclides of use, radionuclides of use, radiation dosimetry methodology and considerations for each treatment in practical use

  7. Dosimetry for electron beam from Microtron accelerator using chemical dosimeters

    International Nuclear Information System (INIS)

    Joseph, Praveen; Nairy, Rajesha; Sanjeev, Ganesh; Narayana, Y.

    2014-01-01

    The Microtron is a simple, compact, low cost electron accelerator with excellent beam quality and it can accelerate electrons to relativistic energies. The variable energy Microtron at Mangalore University is used for R and D programmes in basic and applied areas of physics, chemistry, materials science, biological sciences, medical science and industry. While studying the effects of radiation, it is essential to have complete knowledge of absorbed dose. In the present study the absorbed dose and the uniformity of dose distribution at various points due to 8 MeV electron beam from Microtron accelerator has been calculated using different chemical dosimeters. From the dosimetry studies for Microtron accelerator, it is observed that the absorbed doses measured at various dose ranges from 2 Gy to 25 kGy using FBX dosimeters at very low doses, Fricke at intermediate doses and alanine and glutamine at higher doses, varied linearly with increasing electron counts. From the dosimetry studies it is observed that there is a linear relation between dose and electron numbers over a wide range of absorbed doses. It is evaluated that the electron counts of about 1.15 x 10 14 corresponds to an absorbed dose of 100 Gy. Fricke dosimetry was carried out to measure the uniformity in dose distribution at a distance of 30 cm from the beam exit window of the accelerator to ensure the availability of uniform irradiation field size. It is observed that a field size of about 4 x 4 cm is available at 30 cm distance from the beam exit window over which the dose distribution is uniform. The sample size during radiological studies using Microtron was restricted to less than 4 x 4 cm dimension at 30 cm distance from the beam exit window to ensure uniform dose distribution to the sample

  8. Development of A-bomb survivor dosimetry

    International Nuclear Information System (INIS)

    Kerr, G.D.

    1995-01-01

    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

  9. Accidental and retrospective dosimetry using TL method

    International Nuclear Information System (INIS)

    Mesterhazy, D.; Osvay, M.; Kovacs, A.; Kelemen, A.

    2011-01-01

    Complete text of publication follows. The possible risk of an unexpected nuclear accident or violent terror attack necessitates different methods and processes potentially applicable in emergency. After the event fast and reliable dose assessments should be given so that arrangements and intervention could start as soon as possible. Retrospective dosimetry is one of the most important tool of accidental dosimetry for dose estimation when dose measurement was not planned and there is no dose data available as a result of a nuclear accident. Luminescent materials are suitable for retrospective dosimetry using TL and/or OSL analysis. Several materials have luminescence properties in the environment, but in the situation mentioned it is suggested to use not just natural substances, but also personal belongings carried by victims, who received the dose. In our environment many objects can be applied as natural dosimeters, having suitable thermoluminescent (TL) and optically stimulated luminescent (OSL) properties. The paper discusses the recent developments, the analysis of luminescence and the dose response curves of various electronic components and the common (table) salt (NaCl) using Daybreak TL reader for retrospective dosimetry purposes. Basic TL properties of these materials (e.g. fading and reproducibility) have also been investigated and will be shown in this study.

  10. Radiation Protection and Dosimetry. Pt. E

    International Nuclear Information System (INIS)

    Tran Ha Anh

    1991-01-01

    Activities of radiation protection at Nuclear research Institute are performed in: a/personal dosimetry control of its staff and persons working with radiation in hospitals; b/environmental monitoring of radioactive level in Dalat region; c/low-activity waste management. To evaluate human radioactivity intake in Vietnam, we have determined the concentration of radionuclides in air, drinking water and foodstuffs. (author). 2 refs, 4 figs, 2 tabs

  11. EPR DOSIMETRY STUDY FOR POPULATION RESIDING IN THE VICINITY OF FALLOUT TRACE FOR NUCLEAR TEST ON 7 AUGUST 1962.

    Science.gov (United States)

    Zhumadilov, Kassym Sh; Ivannikov, Alexander I; Stepanenko, Valeriy F; Toyoda, Shin; Skvortsov, Valeriy G; Hoshi, Masaharu

    2016-12-01

    The method of electron paramagnetic resonance (EPR) dosimetry using extracted teeth has been applied to human tooth enamel to obtain individual absorbed doses of residents of settlements in the vicinity of the central axis of radioactive fallout trace from the contaminating surface nuclear test on 7 August 1962. Most of the settlements (Kurchatov, Akzhar, Begen, Buras, Grachi, Mayskoe, Semenovka) are located from 70 to 120 km to the North-East from the epicenter of the explosion at the Semipalatinsk Nuclear Test Site (SNTS). This region is basically an agricultural region. A total of 57 teeth samples were collected from these sites. Eight teeth from residents of the Kokpekty settlement, which was not subjected to any radioactive contamination and located 400 km to the Southeast from SNTS, were chosen as a control. The principal findings, using this method, were that the average excess dose obtained after subtraction of the natural background radiation was 13 mGy and ranged up to about 100 mGy all for residents in this region. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  12. EPR dosimetry study for population residing in the vicinity of fallout trace for nuclear test on 7 August 1962

    International Nuclear Information System (INIS)

    Zhumadilov, Kassym Sh.; Ivannikov, Alexander I.; Stepanenko, Valeriy F.; Skvortsov, Valeriy G.; Toyoda, Shin; Hoshi, Masaharu

    2016-01-01

    The method of electron paramagnetic resonance (EPR) dosimetry using extracted teeth has been applied to human tooth enamel to obtain individual absorbed doses of residents of settlements in the vicinity of the central axis of radioactive fallout trace from the contaminating surface nuclear test on 7 August 1962. Most of the settlements (Kurchatov, Akzhar, Begen, Buras, Grachi, Mayskoe, Semenovka) are located from 70 to 120 km to the North-East from the epicenter of the explosion at the Semipalatinsk Nuclear Test Site (SNTS). This region is basically an agricultural region. A total of 57 teeth samples were collected from these sites. Eight teeth from residents of the Kokpekty settlement, which was not subjected to any radioactive contamination and located 400 km to the Southeast from SNTS, were chosen as a control. The principal findings, using this method, were that the average excess dose obtained after subtraction of the natural background radiation was 13 mGy and ranged up to about 100 mGy all for residents in this region. (authors)

  13. Dosimetry and stability studies of the boron neutron capture therapy agent F-BPA-Fr using PET and MRI

    Science.gov (United States)

    Dyke, Jonathan Paul

    The treatment of deep seated brain tumors such as glioblastoma Multiforme has been unsuccessful for many patients. Surgical debulking, chemotherapy and standard radiotherapy have met with limited success. Boron neutron capture therapy offers a binary mode brachytherapy based on the following capture reaction that may provide an innovative alternative to standard forms of treatment:10B + n /to/ 11B /to 7Li + 4He + 2.31 MeVBoron is chemically attached to a tumor binding compound creating a non-toxic neutron absorber. A dose of epithermal neutrons provides the catalyst to produce the lithium and alpha particles which destroy any tissue within a length of one cell diameter from the boron compound. This dissertation uses 19F-MRI and 18F-PET to provide answers to the localization and biodistribution questions that arise in such a treatment modality. Practical patient dosimetry and actual treatment planning using the PET data is also examined. Finally, theoretical work done in the areas of compartmental modelling dealing with pharmacokinetic uptake of the PET radiotracer and dose analysis in microdosimetry is also presented.

  14. Neutron spectrometry and dosimetry with neural networks and Bonner spheres: a study to reduce the spheres number

    International Nuclear Information System (INIS)

    Espinoza G, J. G.; Martinez B, M. R.; Leon P, A. A.; Hernandez P, C. F.; Castaneda M, V. H.; Solis S, L. O.; Castaneda M, R.; Ortiz R, J. M.; Vega C, H. R.; Mendez, R.; Gallego, E.; De Sousa L, M. A.

    2016-10-01

    For neutron spectrometry and neutron dosimetry, the Bonner spheres spectrometric system has been the most widely used system, however, the number, size and weight of the spheres composing the system, as well as the need to use a reconstruction code and the long periods of time used to carry out the measurements are some of the disadvantages of this system. For the reconstruction of the spectra, different techniques such as artificial neural networks of reverse propagation have been used. The objective of this work was to reduce the number of Bonner spheres and to use counting speeds in a reverse propagation neural network, optimized by means of the robust design methodology, to reconstruct the neutron spectra. For the design of the neural network we used the neutron spectra of the IAEA and the response matrix of the Bonner spheres with 6 LiI(Eu) detector. The performance of the network was compared; using 7 Bonner spheres against other cases where only 2 and one sphere are used. The network topologies were trained 36 times for each case keeping constant the objective error (1E(-3)), the training algorithm was trains cg and the robust design methodology to determine the best network architectures. With these, the best and worst results were compared. The results obtained using 7 spheres were similar to those with the 5-in sphere, however is still in an information analysis stage. (Author)

  15. Evaluation of Alpha-Therapy with Radium-223-Dichloride in Castration Resistant Metastatic Prostate Cancer-the Role of Gamma Scintigraphy in Dosimetry and Pharmacokinetics.

    Science.gov (United States)

    Kairemo, Kalevi; Joensuu, Timo; Rasulova, Nigora; Kiljunen, Timo; Kangasmäki, Aki

    2015-07-30

    Radium-223-dichloride ((223)RaCl₂) is a new bone-seeking calcium analogue alpha-emitter, which has obtained marketing authorization for the treatment skeletal metastases of hormone-refractory prostate cancer. The current treatment regimen is based on six consecutive doses of (223)RaCl₂ at 4 week intervals and the administered activity dose, 50 kBq/kg per cycle is based on patient weight. We analyzed two patients using quantitative serial gamma imaging to estimate dosimetry in tumors and see possible pharmacokinetic differences in the treatment cycles. The lesions were rather well visualized in gamma scintigraphy in spite of low gamma activity (2.0-fold (1.8 vs. 3.6). Of these patients, patient 1 demonstrated a serum PSA response, whereas there was no PSA response in patient 2. From our data, there were maximally up to 4.0-fold differences (62.1 vs. 246.6 ) between the relative absorbed radiation doses between patients as calculated from the quantitative standardized imaging to be delivered in only two lesions, and in the same lesion the maximum difference in the cycles was up to 2.3-fold (107.4 vs. 246.6). Our recommendation based on statistical simulation analysis, is serial measurement at days 0-8 at least 3 times, this improve the accuracy significantly to study the lesion activities, half-lives or calculated relative absorbed radiation doses as calculated from the imaging. Both our patients had originally two metastatic sites in the imaging field; the former patient demonstrated a serum PSA response and the latter demonstrated no PSA response. In these two patients there was no significant difference in the lesion activities, half-lives or calculated relative absorbed radiation doses as calculated from the quantitative imaging. Our results, although preliminary, suggest that dose monitoring can be included as a part of this treatment modality. On the other hand, from the absorbed radiation doses, the response cannot be predicted because with very similar

  16. Dosimetry of 64Cu-DOTA-AE105, a PET tracer for uPAR imaging

    International Nuclear Information System (INIS)

    Persson, Morten; El Ali, Henrik H.; Binderup, Tina; Pfeifer, Andreas; Madsen, Jacob; Rasmussen, Palle; Kjaer, Andreas

    2014-01-01

    64 Cu-DOTA-AE105 is a novel positron emission tomography (PET) tracer specific to the human urokinase-type plasminogen activator receptor (uPAR). In preparation of using this tracer in humans, as a new promising method to distinguish between indolent and aggressive cancers, we have performed PET studies in mice to evaluate the in vivo biodistribution and estimate human dosimetry of 64 Cu-DOTA-AE105. Methods: Five mice received iv tail injection of 64 Cu-DOTA-AE105 and were PET/CT scanned 1, 4.5 and 22 h post injection. Volume-of-interest (VOI) were manually drawn on the following organs: heart, lung, liver, kidney, spleen, intestine, muscle, bone and bladder. The activity concentrations in the mentioned organs [%ID/g] were used for the dosimetry calculation. The %ID/g of each organ at 1, 4.5 and 22 h was scaled to human value based on a difference between organ and body weights. The scaled values were then exported to OLINDA software for computation of the human absorbed doses. The residence times as well as effective dose equivalent for male and female could be obtained for each organ. To validate this approach, of human projection using mouse data, five mice received iv tail injection of another 64 Cu-DOTA peptide-based tracer, 64 Cu-DOTA-TATE, and underwent same procedure as just described. The human dosimetry estimates were then compared with observed human dosimetry estimate recently found in a first-in-man study using 64 Cu-DOTA-TATE. Results: Human estimates of 64 Cu-DOTA-AE105 revealed the heart wall to receive the highest dose (0.0918 mSv/MBq) followed by the liver (0.0815 mSv/MBq), All other organs/tissue were estimated to receive doses in the range of 0.02–0.04 mSv/MBq. The mean effective whole-body dose of 64 Cu-DOTA-AE105 was estimated to be 0.0317 mSv/MBq. Relatively good correlation between human predicted and observed dosimetry estimates for 64 Cu-DOTA-TATE was found. Importantly, the effective whole body dose was predicted with very high

  17. Report of results of the tests of evaluation of the operation of service of personal dosimetry of the CNLV; Informe de resultados de las pruebas de evaluacion del funcionamiento de servicio de dosimetria personal de la CNLV

    Energy Technology Data Exchange (ETDEWEB)

    Alvarez R, J.T.; Tovar M, V.M. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)

    2005-11-15

    The ININ realized the evaluation of the service of personal dosimetry in the CNLV, in the categories: IV.- (Photons of high energy of {sup 137}Cs) and the VA.- (Particles beta of {sup 90}Sr/{sup 90}Y); in the category IV the test was satisfactory, however in the chart 1 has an underestimation a the American Standard HP over the value true conventional of a 9%; for this irregularity it is recommended to revise the procedures of evaluation of the process and the determination of the chart 1 of the HP. In the category VA, the test is also satisfactory, however the results contrasted with the chart 2 and the HP, the values were overestimated in 29% of the true conventional value, and for that problem is recommended to revise the evaluation procedures in contrast with the values determined by the standard HP. (Author)

  18. A dosimetry study comparing NCS report-5, IAEA TRS-381, AAPM TG-51 and IAEA TRS-398 in three clinical electron beam energies

    International Nuclear Information System (INIS)

    Palmans, Hugo; Nafaa, Laila; Patoul, Nathalie de; Denis, Jean-Marc; Tomsej, Milan; Vynckier, Stefaan

    2003-01-01

    New codes of practice for reference dosimetry in clinical high-energy photon and electron beams have been published recently, to replace the air kerma based codes of practice that have determined the dosimetry of these beams for the past twenty years. In the present work, we compared dosimetry based on the two most widespread absorbed dose based recommendations (AAPM TG-51 and IAEA TRS-398) with two air kerma based recommendations (NCS report-5 and IAEA TRS-381). Measurements were performed in three clinical electron beam energies using two NE2571-type cylindrical chambers, two Markus-type plane-parallel chambers and two NACP-02-type plane-parallel chambers. Dosimetry based on direct calibrations of all chambers in 60 Co was investigated, as well as dosimetry based on cross-calibrations of plane-parallel chambers against a cylindrical chamber in a high-energy el