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Sample records for biological dosimetry study

  1. Biological dosimetry of X-rays by micronuclei study

    International Nuclear Information System (INIS)

    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 D2 where. Y is the number micronuclei per cell and D the dose. the curve is compared with those produced elsewhere

  2. Biological Dosimetry of X-rays by micronuclei study

    International Nuclear Information System (INIS)

    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

  3. Biological dosimetry studies for boron neutron capture therapy at the RA-1 research reactor facility

    International Nuclear Information System (INIS)

    Initial physical dosimetry measurements have been completed using activation spectrometry and thermoluminescent dosimeters to characterize the BNCT facility developed at the RA-1 research reactor operated by the National Atomic Energy Commission in Buenos Aires. Biological dosimetry was performed employing the hamster cheek pouch oral cancer model previously validated for BNCT studies by our group. Results indicate that the RA-1 neutron source produces useful dose rates for BNCT studies but that some improvements in the initial configuration will be needed to optimize the spectrum for thermal-neutron BNCT research applications. (author)

  4. Biological dosimetry; Dosimetria biologica

    Energy Technology Data Exchange (ETDEWEB)

    Guerrero C, C.; Arceo M, C., E-mail: citlali.guerrero@inin.gob.m [ININ, Departamento de Biologia, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)

    2010-07-01

    In the Instituto Nacional de Investigaciones Nucleares (ININ) the works to establish a laboratory of biological dosimetry were initiated in 1998, with the purpose that could assist any situation with respect to the exposition to radiation, so much of the occupational exposed personnel as of individuals not related with the handling of radio-active material. The first activity that was realized was to develop the corresponding curves in vitro of dose response for different qualities and radiation types. In the year 2000 the curve corresponding to the gamma radiation of {sup 60}Co was published and up to 2002 the curve corresponding to the X rays of 58 KeV, 120 and 250 kVp. In all the cases, the curves contain the requirements to be used in the determination of the exposition dose. At the present time the curves dose-response are developing for neutrons take place in the reactor Triga Mark III of ININ. Additionally to these activities, cases of suspicion of accidental exposition to radiation have been assisted, using in a beginning the curves published by the IAEA and, from the year 2000, the curves developed in the ININ. (Author)

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

    International Nuclear Information System (INIS)

    Biological Dosimetry allows individual dose assessments based on the effect produced by ionizing radiation on a given biological parameter. The current biological endpoint being scored is chromosomal aberrations, relying on a lymphocytes culture from the patient's blood. The measured yield of chromosome aberrations is referred to a calibration curve obtaining the whole body dose. Different scenarios of overexposure can be taken into account by modifying the calculations leading to the dose estimate. Differentiated Thyroid Carcinoma patients undergo thyroidectomy followed by internal radiotherapy with 131I. The treatment's success entails the delivery of a lethal dose to the tumour within the maximum tolerable dose to a critical organ (blood doses over 2 Gy could lead to bone marrow depression). Currently, there is no established agreement for the selection of radioiodine dosage. Historically, the empiric approach, based on clinical and biochemical data, has been recommended. Nevertheless, this method may not be associated with optimal outcomes. On the other hand, the dosimetric approach attempts to determine the maximum allowable activity to be administered, establishing its biokinetics by a diagnostic 131I study. The methodology may be modified to further individualized treatment, however it requires validation. Biological dosimetry provides an independent measure of radiotherapy effect, as such it might aid in the validation process. Nonetheless, biological dosimetry has traditionally been applied in cases of external and accidental overexposure to ionizing radiation. Accordingly, it is mandatory to assess its value in medical internal incorporations (main objective of the present study). The applied treatment strategy comprises whole body dose assessment by biological and internal dosimetry in order to administer a personalized therapeutic activity. Overall, 20 patients with differentiated thyroid carcinoma were included in the study. For biological dosimetry

  6. Internal dosimetry for alpha emitters radiopharmaceuticals in biological tissue studied with the FLUKA code 10

    International Nuclear Information System (INIS)

    Clinical practices for neoplastic disease diagnose and treatment are based on the incorporation of α, β and γ radiotracers and radiopharmaceuticals, which might be associated with potential damage. Thus, being necessary accurate dosimetry strategies. In vivo absorbed dose appears as an ideal solution. However, its implementation in clinics does not attain enough reliability. On the other hand, different approaches were proposed for internal dosimetry calculations. Some special analytical methodologies were developed by the Committee on Medical Internal Radiation Dose (MIRD) to assess organ level dose values in nuclear medicine. Improvements in informatics achieve better computation performance, but Monte Carlo approaches for patient-specific dosimetry are sometimes high time-consuming l imitating its use in routine clinical practices. Analytical approaches introduce kernel convolution techniques aimed to patient spe ci dosimetry. Although scattering effects are not accurately handled, these methods are capable of fast dosimetry computation based on photon Energy Deposition Kernel (EDK and particle Dose Point Kernel (DPK) assessed for radionuclides in order to perform further dosimetry calculations. EDK and DPK are obtained according to specific source emission. It was considered a point source isotropically emitting within an homogeneous medium, so that radiation transport is accounted as uniformly distributed over concentric spherical regions by shell tally. Dedicated Monte Carlo simulations were performed by a subroutine adapted from the FLUKA co se. In water EDK were evaluated at different photon energies and some typical γ-emitters radiopharmaceuticals; whereas DPK were obtained for both α and β emitters. Additionally, EDK and DPK were calculated for several biological tissues. Obtained results agree with energy loss from stopping power calculated by Bethe-Bark as- Bloch theory in the continuous slowing down approximation

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

    International Nuclear Information System (INIS)

    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.)

  8. Biological dosimetry: biochemical and cellular parameters

    International Nuclear Information System (INIS)

    Early after the beginning of radiobiology studies, biochemistry has led to research of a biological dosimeter. From an extensive literature review, methods were selected that might be suitable for dose assessment via biochemical indicators. By now, research both in laboratory animals and in therapeutic or accidental human exposures, do not allow to retain a biochemical parameter alone for the purpose of diagnosis or prognosis. Several enzymatic activities have been precociously studied after irradiation: from these studies, it seems that analysis of four enzymatic activities in serum (serum glutamic oxaloacetic transaminase, amylase, lactic dehydrogenase, alkaline phosphatase) could be the most useful dosimetry system for mass sorting. Detection of DNA damage or methods for measuring somatic mutations are currently advancing and provide important new opportunities for biological dosimetry of low doses

  9. Potential Technology for Studying Dosimetry and Response to Airborne Chemical and Biological Pollutants

    Energy Technology Data Exchange (ETDEWEB)

    Timchalk, Chuck; Trease, Harold E.; Trease, Lynn L.; Minard, Kevin R.; Corley, Rick A.

    2001-06-01

    Advances in computational, and imaging techniques have enabled the rapid development of 3-dimensional (3-D) models of biological systems in unprecedented detail. Using these advances, 3-D models of the lungs and nasal passages of the rat and human are being developed to ultimately improve predictions of airborne pollutant dosimetry. Techniques for imaging the respiratory tract by magnetic resonance (MR) imaging were developed to improve the speed and accuracy of geometric data collection for mesh reconstruction. The MR imaging resolution is comparable to that obtained by manual measurements but at much greater speed and accuracy. Newly developed software (NWGrid) was utilized to translate imaging data from MR into 3-D mesh structures. Together, these approaches significantly reduced the time to develop a 3-D model. This more robust airway structure will ultimately facilitate modeling gas or vapor exchange between the respiratory tract and vasculature as well as enable linkages of dosimetry with cell response models. The 3-D, finite volume, visco-elastic mesh structures forms the geometric basis for computational fluid dynamics modeling of inhalation, exhalation and the delivery of individual particles (or concentrations of gas or vapors) to discrete regions of the respiratory tract. The ability of these 3-D models to resolve dosimetry at such a high level of detail will require new techniques to measure regional airflows and particulate deposition for model validation.

  10. Radio-analysis. Applications: biological dosimetry

    International Nuclear Information System (INIS)

    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.)

  11. Development of radiation biological dosimetry

    International Nuclear Information System (INIS)

    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

  12. 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.

  13. Cytogenetic biological dosimetry. Dose estimative in accidental exposure

    International Nuclear Information System (INIS)

    The methodology of cytogenetic biological dosimetry is studied. The application in estimation of dose in five cases of accidental exposure is reported. An hematological study and culture of lymphocytes is presented. (M.A.C.)

  14. Biological dosimetry - Dose estimation method using biomakers

    International Nuclear Information System (INIS)

    The individual radiation dose estimation is an important step in the radiation risk assessment. In case of radiation incident or radiation accident, sometime, physical dosimetry method can not be used for calculating the individual radiation dose, the other complement method such as biological dosimetry is very necessary. This method is based on the quantitative specific biomarkers induced by ionizing radiation, such as dicentric chromosomes, translocations, micronuclei... in human peripheral blood lymphocytes. The basis of the biological dosimetry method is the close relationship between the biomarkers and absorbed dose or dose rate; the effects of in vitro and in vivo are similar, so it is able to generate the calibration dose-effect curve in vitro for in vivo assessment. Possibilities and perspectives for performing biological dosimetry method in radiation protection area are presented in this report. (author)

  15. Dosimetry and biological effects of fast neutrons

    International Nuclear Information System (INIS)

    This thesis contains studies on two types of cellular damage: cell reproductive death and chromosome aberrations induced by irradiation with X rays, gamma rays and fast neutrons of different energies. A prerequisite for the performance of radiobiological experiments is the determination of the absorbed dose with a sufficient degree of accuracy and precision. Basic concepts of energy deposition by ionizing radiation and practical aspects of neutron dosimetry for biomedical purposes are discussed. Information on the relative neutron sensitivity of GM counters and on the effective point of measurement of ionization chambers for dosimetry of neutron and photon beams under free-in-air conditions and inside phantoms which are used to simulate the biological objects is presented. Different methods for neutron dosimetry are compared and the experimental techniques used for the investigations of cell reproductive death and chromosome aberrations induced by ionizing radiation of different qualities are presented. Dose-effect relations for induction cell inactivation and chromsome aberrations in three cultured cell lines for different radiation qualities are presented. (Auth.)

  16. 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.

  17. Biological dosimetry, scopes and limitations

    International Nuclear Information System (INIS)

    The analysis of the aberrations in chromosomes is an alternative to establish the exposure dose to the radiation, when the information provided by the traditional physical methods is insufficient. There are diverse causes by which it can reached to apply an alternative system, such is the case of exposures of another persons to the management of radiation sources, which not carry physical dosemeter. Contrary case is to the occupational exposure personnel (OEP), what must to utilize some system for determining the exposure dose, even so can be needed the case for more information. In any case, the cells from the affected person are the alternative without the biological system be overlap to the physical, it is complementary. (Author)

  18. DRDC Ottawa working standard for biological dosimetry

    International Nuclear Information System (INIS)

    This Standard provides quality assurance, quality control, and evaluation of the performance criteria for the purpose of accreditation of the Radiation Biology laboratory at Defence Research and Development Canada - Ottawa (DRDC Ottawa) using biological dosimetry to predict radiation exposure doses. The International Standard (ISO 19238) and the International Atomic Energy Association (IAEA) Technical Report Series No. 405 are used as guiding documents in preparation of this working document specific to the DRDC Ottawa Radiation Biology Laboratory. This Standard addresses: 1. The confidentiality of personal information, for the customer and the service laboratory; 2. The laboratory safety requirements; 3. The calibration sources and calibration dose ranges useful for establishing the reference dose-effect curves allowing the dose estimation from chromosome aberration frequency, and the minimum detection levels; 4. Transportation criteria for shipping of test samples to the laboratory; 5. Preparation of samples for analysis; 6. The scoring procedure for unstable chromosome aberrations used for biological dosimetry; 7. The criteria for converting a measured aberration frequency into an estimate of absorbed dose; 8. The reporting of results; 9. The quality assurance and quality control plan for the laboratory; and 10. Informative annexes containing examples of a questionnaire, instructions for customers, a data sheet for recording aberrations, a sample report and other supportive documents. (author)

  19. DRDC Ottawa working standard for biological dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Segura, T.M.; Prud' homme-Lalonde, L. [Defence Research and Development Canada, Ottawa, Ontario (Canada); Thorleifson, E. [Health Canada, Gatineau, Quebec (Canada); Lachapelle, S.; Mullins, D. [JERA Consulting (Canada); Qutob, S. [Health Canada, Gatineau, Quebec (Canada); Wilkinson, D.

    2005-07-15

    This Standard provides quality assurance, quality control, and evaluation of the performance criteria for the purpose of accreditation of the Radiation Biology laboratory at Defence Research and Development Canada - Ottawa (DRDC Ottawa) using biological dosimetry to predict radiation exposure doses. The International Standard (ISO 19238) and the International Atomic Energy Association (IAEA) Technical Report Series No. 405 are used as guiding documents in preparation of this working document specific to the DRDC Ottawa Radiation Biology Laboratory. This Standard addresses: 1. The confidentiality of personal information, for the customer and the service laboratory; 2. The laboratory safety requirements; 3. The calibration sources and calibration dose ranges useful for establishing the reference dose-effect curves allowing the dose estimation from chromosome aberration frequency, and the minimum detection levels; 4. Transportation criteria for shipping of test samples to the laboratory; 5. Preparation of samples for analysis; 6. The scoring procedure for unstable chromosome aberrations used for biological dosimetry; 7. The criteria for converting a measured aberration frequency into an estimate of absorbed dose; 8. The reporting of results; 9. The quality assurance and quality control plan for the laboratory; and 10. Informative annexes containing examples of a questionnaire, instructions for customers, a data sheet for recording aberrations, a sample report and other supportive documents. (author)

  20. Studying Biology to Understand Risk: Dosimetry Models and Quantitative Adverse Outcome Pathways

    Science.gov (United States)

    Confidence in the quantitative prediction of risk is increased when the prediction is based to as great an extent as possible on the relevant biological factors that constitute the pathway from exposure to adverse outcome. With the first examples now over 40 years old, physiologi...

  1. 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.

  2. 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.

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

    International Nuclear Information System (INIS)

    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 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. Therefore, a prospective study on the decline of unstable chromosome aberrations is being conducted, considering the damage induced

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

    International Nuclear Information System (INIS)

    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)

  5. Studies to validate the measurement of translocation frequency in peripheral blood lymphocytes by GTG-banding and chromosome painting for biological dosimetry

    International Nuclear Information System (INIS)

    The wide use of radiation sources for medical, industrial, agricultural, research and military purposes increases the public concern and associated risks of overexposure. Biological dosimeters plays a important role in circumstances where physical dosimetry either unavailable or gives ambiguous dose estimates based upon biological indicators. Among various biological indicators, cytogenetic indicators have become routine tools for dose assessment and its biological effect

  6. A Novel Biological Dosimetry Method for Monitoring Occupational Radiation Exposure in Diagnostic and Therapeutic Wards: From Radiation Dosimetry to Biological Effects

    OpenAIRE

    Heydarheydari, S.; Haghparast, A.; Eivazi, M.T.

    2016-01-01

    Background and Objective Professional radiation workers are occupationally exposed to long-term low levels of ionizing radiation. Occupational health hazards from radiation exposure, in a large occupational segment of the population, are of special concern. Biological dosimetry can be performed in addition to physical dosimetry with the aim of individual dose assessment and biological effects. Methods In this biodosimetry study, some hematological parameters have been examined in 40 exposed a...

  7. 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.)

  8. The micronucleus test in biological dosimetry

    International Nuclear Information System (INIS)

    The determination of micronuclei in lymphocytes on the basis of the Cytochalasine B method may already be regarded as a most useful tool following short-term wholebody exposure to doses in the range between approx. 0.3 and 7 Gy and thus offers a genuine alternative to the conventional analysis of chromosomes. Further efforts in the research on micronuclei as a biological system of dosimetry should primarily be made in the field of radiosensitive subpopulations and, additionally, the field of automated evaluation procedures. It is to be expected that this will permit the limit of detection to be lowered to doses of even less than approx. 0.2 - 0.3 Gy. (orig.)

  9. The status of the seventh report in the series Biological Effects of Ionizing Radiations and a revised dosimetry for the Radiation Effects Research Foundation's A-bomb studies

    International Nuclear Information System (INIS)

    Results of a National Academies workshop and feasibility study led US Governmental agencies to request the Board on Radiation Effects Research of the National Research Council to commence a risk assessment study in 1998 as the seventh report in the series Biological Effects of Ionizing Radiations (BEIR VII). Originally targeted for completion in the autumn of 2001, the study Potential Health Effects of Exposure to Low Dose, Low-LET Ionizing Radiation was extended until the autumn of 2003 at the request of the sponsors. Two factors contributing to this decision are discussed: a revised dosimetry to update DS86 for the Radiation Effects Research Foundation's A-bomb-survivor studies and the potential for new information to become available from low-dose studies that are under way. Epidemiological and biological data since BEIR V are being considered by a BEIR VII committee composed of 17 members. The committee's statement of task is reviewed along with the major recommendations of the recent National Research Council report on the status of DS86 - recommendations that are being implemented by US and Japan dosimetry working groups. (author)

  10. Dosimetry

    International Nuclear Information System (INIS)

    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

  11. Nuclear accident dosimetry intercomparison studies.

    Science.gov (United States)

    Sims, C S

    1989-09-01

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

  12. Premature chromosome condensation: A novel method for biological dosimetry

    International Nuclear Information System (INIS)

    In this study, we have investigated the utility of different test systems for biological dosimetry and possible their application for therapy regime. Human peripheral blood lymphocytes were X-irradiated and mixed in different proportions with unirradiated lymphocytes. The frequencies of chromosomal aberrations were determined by the formation of dicentrics, excess of premature chromosome condensation fragments and micronuclie in cytochalasin B-blocked binucleated cells. These responses were with regard to estimate the dose received and to determine the population of unexposed cells (useful for the purpose of therapy) are discussed. 6 refs, 3 figs, 3 tabs

  13. Biological dosimetry-knowing what happened

    International Nuclear Information System (INIS)

    Effective medical management of a suspected radiation overexposure incident necessitates recording dynamic medical data and measuring appropriate radiation bioassays in order to provide diagnostic information to the treating physician and dose assessment for the personnel radiation protection records. Biological Assessment Tool (BAT), a radiation casualty management software application available at the AFRRI's website (www.afrri.usuhs.mil), was developed to facilitate medical recording and to assist in bioassay dose predictions. Prodromal signs and symptoms as well as the body location and degree of transitory radiation-induced erythema should be recorded. Goans and colleagues have recently published dose prediction models for the prodromal symptom, time until onset of vomiting, following photon and criticality accident exposures. A complete blood cell count (CBC) with white cell differential should be obtained immediately after exposure, three times a day for the next 2-3 days, and then twice a day for the following 3- 6 days. Lymphocyte cell counts and lymphocyte depletion kinetics provide a dose assessment prediction between 1 and 10 Gy photon equivalent dose range. A blood sample should also be taken for dose assessment, following coordination with a qualified radiation cytogenetic biodosimetry laboratory, typically 24 hours after exposure using the 'gold standard' lymphocyte-dicentric radiation bioassay. Several of these cytogenetic biodosimetry laboratories use the premature chromosome condensation (PCC) bioassay, which permits dose assessment at higher doses (>5 Gy photon equivalent and acute high-dose rate exposures). Other opportunistic dosimetry approaches should be considered if available. Automated instrumentation to accomplish sample preparation and analysis for the conventional cytogenetic-based bioassays need to be integrated and beta tested in reference cytogenetic biodosimetry laboratories. Complimentary novel interphase-based cytological

  14. Trends in biological dosimetry: an overview

    Directory of Open Access Journals (Sweden)

    Ademir Amaral

    2002-09-01

    Full Text Available Biological dosimetry (biodosimetry is based on investigations of induced biological effects (biomarkers in order to correlate them with radiation dose. Among the indicators employed in biodosimetry, scoring of chromosome aberrations is the most reliable method to quantify individual exposure to ionizing radiation. The technique, applied to circulating lymphocytes, has been developed into a routine procedure to evaluate the dose in the case of real or suspected accidental exposure. Considering the radiosensitivity of lymphocytes in vitro and in vivo as being the same, the dose effect relationship obtained after in vitro irradiation of blood has been widely used, with medico-legal value, for evaluating individual radiation exposure. This report presents an overview of strengths, limitations and perspectives on biodosimetry.A dosimetria biológica (biodosimetria é baseada na investigação de efeitos biológicos induzidos (bioindicadores objetivando relacioná-los com dose absorvida pela exposição à radiação ionizante. Entre os indicadores empregados na biodosimetria, a quantificação de aberrações cromossômicas é o método mais confiável na avaliação de uma exposição à radiação ionizante. A técnica, aplicada para análises de linfócitos do sangue periférico, tem sido empregada em procedimentos de rotina para avaliação de dose em caso de acidentes ou de suspeita de exposição. Considerando a radiosensibilidade de linfócitos como sendo a mesma tanto in vivo quanto in vitro, a relação dose-efeito obtida após uma irradiação in vitro do sangue tem sido amplamente utilizada, com valor médico-legal, para avaliação de exposições de indivíduos à radiação. Neste contexto, este trabalho apresenta uma breve revisão das potencialidades, limitações e perspectivas da biodosimetria.

  15. Biological dosimetry of ionizing radiation by chromosomal aberration analysis

    International Nuclear Information System (INIS)

    Biological dosimetry consists of estimating absorbed doses for people exposed to radiation by mean biological methods. Several indicators used are based in haematological, biochemical, and cytogenetic data, although nowadays without doubt, the cytogenetic method is considered to be the most reliable. In this case, the study ol chromosomal aberrations, normally dicentric chromosomes, in peripheral lymphocytes can be related to absorbed dose through an experimental calibration curve. An experimental dose-response curve, using dicentric chromosomes analysis, X-rays at 300 kVp, 114 rad/min and temperature 37 degree celsius has been produced. Experimental data is fitted to model Y =α + β1D + β2D 2 , where Y is the number of dicentrics per cell and D the dose. The curve is compared with those produced elsewhere. (Author) 14 refs

  16. Dosimetry studies in Zaborie village

    Energy Technology Data Exchange (ETDEWEB)

    Takada, J. E-mail: jtakada@ipc.hiroshima-u.ac.jp; Hoshi, M.; Endo, S.; Stepanenko, V.F.; Kondrashov, A.E.; Petin, D.; Skvortsov, V.; Ivannikov, A.; Tikounov, D.; Gavrilin, Y.; Snykov, V.P

    2000-05-15

    Dosimetry studies in Zaborie, a territory in Russia highly contaminated by the Chernobyl accident, were carried out in July, 1997. Studies on dosimetry for people are important not only for epidemiology but also for recovery of local social activity. The local contamination of the soil was measured to be 1.5-6.3 MBq/m{sup 2} of Cs-137 with 0.7-4 {mu}Sv/h of dose rate. A case study for a villager presently 40 years old indicates estimations of 72 and 269 mSv as the expected internal and external doses during 50 years starting in 1997 based on data of a whole-body measurement of Cs-137 and environmental dose rates. Mean values of accumulated external and internal doses for the period from the year 1986 till 1996 are also estimated to be 130 mSv and 16 mSv for Zaborie. The estimation of the 1986-1996 accumulated dose on the basis of large scale ESR teeth enamel dosimetry provides for this village, the value of 180 mSv. For a short term visitor from Japan to this area, external and internal dose are estimated to be 0.13 mSv/9d (during visit in 1997) and 0.024 mSv/50y (during 50 years starting from 1997), respectively.

  17. New methodologies of biological dosimetry applied to human protection

    International Nuclear Information System (INIS)

    Biological dosimetry is a diagnostic methodology for the measurement of the individual dose absorbed in the case of accidental overexposition to ionizing radiation. It is demonstrated how in vitro radiobiological and chemobiological studies using cytogenetic methods (count of chromosomal aberrations and micronuclei) on human lymphocytes from healthy subjects and individuals undergoing radiotherapy or chemotherapy, as well as on lymphocytes of mammals other than man (comparative cytogenetics), can help to increase the basic radiobiological and chemobiological scientific information. Such information gives a valid contribution to understanding of the action of ionizing radiation or of pharmaceuticals on cells and, in return, can be of value to human radioprotection and chemoprotection. Cytogenetic studies can be summerized as follows: a) biodosimetry (estimate of dose received after accidental events); b) individual radiosensitivity (level of individual response); c) clinical radiobiology and chemobiology (individual response to radiopharmaceuticals, to radiotherapy and to chemopharmaceuticals); d) comparative radiobiology (cytogenetic studies on species other than man); e) animal model in the environmental surveillance

  18. Confocal microscopy, a tool for biological dosimetry in tissues

    International Nuclear Information System (INIS)

    Because standard histological methods and related observation are very time consuming, only a few studies have concerned biological dosimetry in tissues. This experimental approach is however the only one that could characterize a heterogeneous irradiation such as that induced after internal contamination with α and/or β emitters. The aim advantage of CM is to observe thin optical sections (50μm) which allows observation of many cells and to score events even those occurring at a low frequency if an appropriate staining has been performed. Two rat tissues have been studies, cerebellum during its histogenesis which was irradiated from bone after 90Sr contamination, and lungs from adults after radon daughter inhalation. In conclusion, our results demonstrate that CM might be an appropriate method to characterize the heterogeneous distribution of doses after internal contamination. (authors)

  19. Future development of biologically relevant dosimetry.

    Science.gov (United States)

    Palmans, H; Rabus, H; Belchior, A L; Bug, M U; Galer, S; Giesen, U; Gonon, G; Gruel, G; Hilgers, G; Moro, D; Nettelbeck, H; Pinto, M; Pola, A; Pszona, S; Schettino, G; Sharpe, P H G; Teles, P; Villagrasa, C; Wilkens, J J

    2015-01-01

    Proton and ion beams are radiotherapy modalities of increasing importance and interest. Because of the different biological dose response of these radiations as compared with high-energy photon beams, the current approach of treatment prescription is based on the product of the absorbed dose to water and a biological weighting factor, but this is found to be insufficient for providing a generic method to quantify the biological outcome of radiation. It is therefore suggested to define new dosimetric quantities that allow a transparent separation of the physical processes from the biological ones. Given the complexity of the initiation and occurrence of biological processes on various time and length scales, and given that neither microdosimetry nor nanodosimetry on their own can fully describe the biological effects as a function of the distribution of energy deposition or ionization, a multiscale approach is needed to lay the foundation for the aforementioned new physical quantities relating track structure to relative biological effectiveness in proton and ion beam therapy. This article reviews the state-of-the-art microdosimetry, nanodosimetry, track structure simulations, quantification of reactive species, reference radiobiological data, cross-section data and multiscale models of biological response in the context of realizing the new quantities. It also introduces the European metrology project, Biologically Weighted Quantities in Radiotherapy, which aims to investigate the feasibility of establishing a multiscale model as the basis of the new quantities. A tentative generic expression of how the weighting of physical quantities at different length scales could be carried out is presented. PMID:25257709

  20. Alternative statistical methods for cytogenetic radiation biological dosimetry

    CERN Document Server

    Fornalski, Krzysztof Wojciech

    2014-01-01

    The paper presents alternative statistical methods for biological dosimetry, such as the Bayesian and Monte Carlo method. The classical Gaussian and robust Bayesian fit algorithms for the linear, linear-quadratic as well as saturated and critical calibration curves are described. The Bayesian model selection algorithm for those curves is also presented. In addition, five methods of dose estimation for a mixed neutron and gamma irradiation field were described: two classical methods, two Bayesian methods and one Monte Carlo method. Bayesian methods were also enhanced and generalized for situations with many types of mixed radiation. All algorithms were presented in easy-to-use form, which can be applied to any computational programming language. The presented algorithm is universal, although it was originally dedicated to cytogenetic biological dosimetry of victims of a nuclear reactor accident.

  1. Study and development of radiothermoluminescent dosimetry

    International Nuclear Information System (INIS)

    After briefly reviewing bibliography concerning the mechanism of radiothermoluminescence and its use in dosimetry, we have concentrated on studies of three thermoluminescent products: magnesium activated lithium fluoride, alumina and calcium sulfate activated with either dysprosium or thulium. In particular, the preparation and singular properties of a new type of lithium fluoride stabilised with sodium, created especially for dosimetric purposes, is described. The physical characteristics of these three products, their emission spectra and their trap parameters, have been studied and we have analysed, both theoretically and experimentally, their dosimetric properties, paying particular attention to their relative chromatic sensitivity to photons and neutrons. It is shown that alumina exhibits an exceptional neutron thermoluminescent yield which points to a potential interest in this material which is little used to date. The deep trapping levels of these products have been studied and some levels found appearing at temperatures above 6000C: these can be used for radiation dosimetry in enclosures at temperatures between 400 and 4500C. Finally, a brief outline of radiothermoluminescent applications of these products in the radioprotection, medical, biological, archeological and industrial fields is presented

  2. Current research and service activities of AFRRI's biological dosimetry program

    International Nuclear Information System (INIS)

    Full text: The long-range goal of the Armed Forces Radiobiology Research Institute's (AFRRI) Biological Dosimetry Team is to develop validated radiation bio dosimeters. Our objectives are (1) to establish definitive clinical bioassays for rapid, high-throughput radiation exposure analyses and (2) to develop complimentary triage-type radiation exposure assessment bioassays to support medical treatment decisions. The experimental approach involves two steps. The first is to establish a reference laboratory that uses conventional bioassays for definitive analyses of biological samples. The second step is to develop a validated and forward deployable biological dosimetry capability for rapid radiation dose assessment with an emphasis on the use of molecular biology-based diagnostic platforms. The conventional lymphocyte metaphase-spread dicentric assay was established at AFRRI in accordance with international harmonized protocols and applied to estimate radiation exposure doses in several overexposure accidents. Currently, novel interphase cell-based cytological bioassay that detects cells with chromosomal type aberrations and radiation responsive molecular bio markers (i.e., gene expression, protein) are being validated and optimized for rapid radiation exposure assessment applications. In addition the Biological Assessment Tool (BAT), a radiation casualty management software application, was developed. Available at AFRRI's website (www.afrri.usuhs.mil), BAT permits the recording and communication of relevant radiological and medical information for radiation accidents. These research and service efforts contribute to an improved diagnostic response for accidental overexposures and also have applications in other research fields including radiation therapy and toxicology

  3. Dosimetry of biological irradiations using radiochromic films

    International Nuclear Information System (INIS)

    Delivering accurate radiation dose to blood specimens during biological irradiations is essential in quantifying damage of ionizing radiation. To estimate dose to blood samples as accurately as possible, pieces of EBT2 model GAFCHROMIC™ film were placed within an approximately 10 mm finely ground rice layer that was used to simulate test specimens inside 40 mL plastic flasks. Irradiations of flasks were carried out using an X-RAD 320 irradiator with a beam quality of 320 kVp and a measured half value layer of 1.12 mm Cu, in air and in a full scattering setup which consisted of either rice or Solid Water™ (SW) surrounding flasks, filled to the same level at top of the flasks, together with a 5 cm thick SW slab beneath them. Outputs, per cent depth doses and beam profiles at different depths were measured and compared between setups. For the same setting, the dose delivered to the middle flask under the full scattering setup is 22% larger than with the in-air setup at the depth of the specimen and 9.2% more homogeneous across the specimen thickness of 10 mm (2.3% variation in comparison to the surface). Rice showed a fairly similar performance to SW within 1% at the same depth of 10 mm. Experimental setup based on full scattering conditions was shown to provide faster, more homogenous and fairly uniform dose delivery to biological specimens in comparison to conventionally used in-air setups. (paper)

  4. Biological and clinical dosimetry, July 1, 1964 to December 31, 1984. Final report

    International Nuclear Information System (INIS)

    The goal was to develop systems for the determination of absorbed dose in biological research and clinical applications. The primary method under study is the local absorbed dose calorimeter. In addition, secondary dosimetric systems such as ionization chambers, chemical dosimeters and thermoluminescent dosimeters (TLD) are being developed and applied to provide an absolute basis for the evaluation and comparison of experiments, treatments and other procedures using radiation. In keeping with these objectives this project has accomplished significant advances in the following areas: (1) local absorbed dose calorimetry; (2) neutron dosimetry; (3) dosimetry of ultra-high intensity radiation sources; (4) solid state detector and germanium gamma camera program; (5) dosimetry for brachytherapy; and (6) ''non-isolated sensor'' calorimeters

  5. Sixth personnel dosimetry intercomparison study

    International Nuclear Information System (INIS)

    The Sixth Personnel Dosimetry Intercomparison Study was conducted March 25 to 27, 1980, at the Oak Ridge National Laboratory. Dosimeters from 28 participating agencies were mounted on anthropomorphic phantoms and exposed to a range of low-level dose equivalents (1.8 to 11.5 mSv neutron, 0.1 to 1.1 mSv gamma) which could be encountered during routine personnel monitoring in mixed radiation fields. The Health Physics Research Reactor (HPRR) operated in the steady-state mode served as the source of radiation for six separate exposures. Lucite and concrete shields along with the unshielded reactor were used to provide three different neutron and gamma spectra. Results reported by the participating agencies showed that TLD-albedo and TLD-700 dosimeters generally provided the most accurate measurements of neutron and gamma dose equivalents, respectively. Film was found to be unsatisfactory for measuring neutron doses produced by HPRR spectra in that measured dose equivalents were much lower than reference values. The TLD-100 dosimeters yielded gamma doses which were much too high indicating that this dosimeter type is generally unsuitable for use in mixed radiation fields similar to those encountered in this study without the use of large correction factors. Although the overall reported results exhibited improvement in performance relative to previous intercomparison studies, the composite measured data showed variations of more than a factor of 2 between measurements of the same exposure made by different agencies

  6. Chromosome aberration analysis for biological dosimetry: a review

    International Nuclear Information System (INIS)

    Among various biological dosimetry techniques, dicentric chromosome aberration method appears to be the method of choice in analysing accidental radiation exposure in most of the laboratories. The major advantage of this method is its sensitivity as the number of dicentric chromosomes present in control population is too small and more importantly radiation induces mainly dicentric chromosome aberration among unstable aberration. This report brings out the historical development of various cytogenetic methods, the basic structure of DNA, chromosomes and different forms of chromosome aberrations. It also highlights the construction of dose-response curve for dicentric chromosome and its use in the estimation of radiation dose. (author)

  7. Biological dosimetry: chromosomal aberration analysis for dose assessment

    International Nuclear Information System (INIS)

    In view of the growing importance of chromosomal aberration analysis as a biological dosimeter, the present report provides a concise summary of the scientific background of the subject and a comprehensive source of information at the technical level. After a review of the basic principles of radiation dosimetry and radiation biology basic information on the biology of lymphocytes, the structure of chromosomes and the classification of chromosomal aberrations are presented. This is followed by a presentation of techniques for collecting blood, storing, transporting, culturing, making chromosomal preparations and scaring of aberrations. The physical and statistical parameters involved in dose assessment are discussed and examples of actual dose assessments taken from the scientific literature are given

  8. Biological dosimetry of ionizing radiation in the high dose range

    International Nuclear Information System (INIS)

    The report reviews briefly methods of dose evaluation after exposure to high doses of ionizing radiation. Validation of two methods also is described: micronucleus (Mn) frequency estimation according Muller and Rode and premature chromosome condensation (PCC) combined with painting of 3 pairs of chromosomes in human lymphocytes. According to Muller and Rode, micronucleus frequency per binucleated cells with at least one Mn linearly increases with dose up to 15 Gy and is suitable end-point for biological dosimetry. These authors, however, examined cells from only one donor. The data reported below were obtained for 5 donors; they point to a considerable individual variation of thus measured response to irradiation. Due to the high degree of inter-donor variability, there is no possibility to apply this approach in biological dosimetry in the dose range 5 - 20 Gy gamma 60Co radiation. A linear response up to 10 Gy was observed only in the case of certain donors. In contrast, determination of the dose-effect relationship with the PCC method gave good results (small inter-individual variation, no plateau effect up to dose 10 Gy), so that with a calibration curve it could be used for dose estimation after exposure to doses up to 10 Gy of X or gamma 60Co radiation. (author)

  9. An improved in vitro micronucleus assay to biological dosimetry

    International Nuclear Information System (INIS)

    The biological dosimetry is widely used to estimate the absorbed dose in people occupationally or accidentally exposed to the radiation for a better medical treatment, minimizing the harmful effects. Many techniques and methods have been proposed to detect and quantify the radioinduced lesions in genetic material, among them, the micronucleus (MN) assay. In the present study, we proposed an improved in vitro micronucleus technique that is rapid, sensitive and with minor cell manipulations. Assays were carried out with human tumor cells (MCF-7) seeded (3x104 cells) in slides placed into Petri dishes. Adherent cells were maintained with RPMI medium, supplemented with fetal calf serum, 1 % antibiotics, cytochalasin B (2 μg/mL), and incubated at 37 deg C in the presence of 5% CO2 for 72h. Cells were pre-treated for 24h with aminoguanidine, a nitric oxide synthase inhibitor. Nitric oxide is an intracellular free-radical, involved in DNA double-strand break repair mechanisms. After incubation, adherent cells on slides were briefly fixed with paraformaldehyde and stained with acridine orange (100 μg/mL) for analysis through fluorescence microscopy. Dye fluorescence permitted accurate discrimination between nuclei and micronuclei (bright green) and cytoplasm (red), and made possible a faster counting of binucleated cells. Aminoguanidine (2 mM) induced significant increase (p< 0.05) in frequencies of binucleated cells with micronuclei and in the number of micronuclei per binucleated cell. Data showed that proposed modifications permit to understand an early aspect of NO inhibition and suggested an improved protocol to MN assays. (author)

  10. Biological dosimetry in case of combined radiation injuries

    International Nuclear Information System (INIS)

    The state of biological dosimetry methods and prospects for their development are considered. Attention is paid to biological indicators of radiation injuries caused by nuclear weapons. It is noted, that determination of the number of lymphocytes in the blood in case of combined radiation injuries should be concerned with great care and in each case the analysis results should reffered to critically and supported by the data from other investigations. Promissing are the methods related to dermination of reticulocyte number in the peripheral blood within the irradiation dose range, causing bone marrow form of radiation syndrome, method of leukocyte adhesion and some other methods based on the change of biophysical caracteristics of cell membranes. To increase the information efficiency it is necessary to combine these methods with the methods, based on genetic change registration, and to develop a combined method

  11. Dosimetry

    International Nuclear Information System (INIS)

    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. History, biological effects, and dosimetry of beta radiation

    International Nuclear Information System (INIS)

    There has been a renewed interest in the dosimetry of beta radiation, particularly in the nuclear power industry. This interest is fueled by the current regulatory concern over exposure to hot particles. Hot particles are small, usually microscopic particles of fuel material or activated products produced as a result of neutron activation in a nuclear reactor. In addition, these particles are characterized as having very high specific activity and being composed primarily of beta-emitting radionuclides. Of primary interest in the dosimetry of hot particles is the absorbed dose and/or dose equivalent to the basal layer of the skin. Current federal regulations, as well as international and national radiation protection standards, do not address adequately the exposure of small areas of the skin from a single point source. In this paper, the history of beta dosimetry is reviewed with an emphasis on early beta-radiation exposures, such as those associated with fallout from nuclear weapons. Beta burns due to the black rain associated with the Japanese bombings and fallout studies at the Nevada test site and in the Pacific testing area provided much of the earliest data. Many survivors of the Japanese bombings were exposed to high-intensity beta radiation when they were caught in a rainout of material that had been sucked up into the fireball of the weapon

  13. The method validation step of biological dosimetry accreditation process

    International Nuclear Information System (INIS)

    One of the missions of the Laboratory of Biological Dosimetry (L.D.B.) of the Institute for Radiation and Nuclear Safety (I.R.S.N.) is to assess the radiological dose after an accidental overexposure suspicion to ionising radiation, by using radio-induced changes of some biological parameters. The 'gold standard' is the yield of dicentrics observed in patients lymphocytes, and this yield is converted in dose using dose effect relationships. This method is complementary to clinical and physical dosimetry, for medical team in charge of the patients. To obtain a formal recognition of its operational activity, the laboratory decided three years ago, to require an accreditation, by following the recommendations of both 17025 General Requirements for the Competence of Testing and Calibration Laboratories and 19238 Performance criteria for service laboratories performing biological dosimetry by cyto-genetics. Diagnostics, risks analysis were realized to control the whole analysis process leading to documents writing. Purchases, personnel department, vocational training were also included in the quality system. Audits were very helpful to improve the quality system. One specificity of this technique is that it is not normalized therefore apart from quality management aspects, several technical points needed some validations. An inventory of potentially influent factors was carried out. To estimate their real effect on the yield of dicentrics, a Placket-Burman experimental design was conducted. The effect of seven parameters was tested: the BUdr (bromodeoxyuridine), PHA (phytohemagglutinin) and colcemid concentration, the culture duration, the incubator temperature, the blood volume and the medium volume. The chosen values were calculated according to the uncertainties on the way they were measured i.e. pipettes, thermometers, test tubes. None of the factors has a significant impact on the yield of dicentrics. Therefore the uncertainty linked to their use was considered as

  14. Biological dosimetry after total body irradiation (TBI) for hematologic malignancy patients

    International Nuclear Information System (INIS)

    Purpose: Biological dosimetry based on scoring chromosomal aberrations in peripheral lymphocytes was compared to physical dosimetry done for total body irradiation (TBI) before bone marrow transplantation (BMT) in patients with hematologic malignancies. Patients and Methods: Fifteen patients undergoing TBI were included in the study. A total dose of 12 Gy in 2.5 days was fractionated into 2 or 3 daily doses of 1.8 Gy delivered by a 18 MV linear accelerator (dose rate: 15.8 cGy · min-1). Blood samples were obtained from patients before irradiation and after the first fraction of 1.8 Gy. A standard dose-effect curve was established by in vitro irradiation of healthy volunteer lymphocytes. Chromosomal aberrations were scored by the conventional cytogenetics (CCG) method for unstable anomalies and by fluorescent in situ hybridization (FISH) for stable anomalies. Results: Healthy donor lymphocytes before irradiation yielded 0.1% dicentrics and 0.3% translocations of chromosome 4 (Chr. 4), that is 2.5% for the whole genome. Patients before irradiation had 2% of dicentrics and 1.1% of chromosome 4 translocations. The biologically estimated dose of the 15 patients after exposure to 1.8 Gy was 1.93 Gy (95% CI: 1.85-2.05) according to CCG, and 2.06 Gy (95% CI: 1.75-2.15) by FISH. Conclusion: The dose estimated by biological dosimetry, in this case of homogeneously distributed radiation of TBI, agrees well with the absorbed radiation dose calculated by physical dosimetry

  15. Use of Chromosome Aberration Frequencies for Biological Dosimetry in Man

    International Nuclear Information System (INIS)

    The vast amount of work on chromosome aberrations induced by radiation exposure under defined biological and physical conditions, has shown that there exist strict relationships between aberration frequencies, radiation quality and absorbed dose in a variety of cell systems. These relationships are such that in many irradiated plant and animal systems the frequency of induced chromosome aberrations has been used to give reliable estimates of the radiation dose to which the system was exposed. A similar extrapolation from induced aberration frequency to absorbed dose can be made with human peripheral blood lymphocytes, if such cells are exposed and cultured in vitro under well defined conditions. Moreover, since aberrations induced in lymphocytes following an in vivo exposure can be detected in the cells when subsequently cultured in vitro, the peripheral blood leucocyte system has been utilized for biological dosimetry in cases where individuals have been accidentally exposed to radiations. In the case of uniform whole-body exposure of an individual, and under defined conditions of in vitro culture, the system may be expected to fulfil most of the requirements for a sensitive and accurate biological measure of absorbed dose. In this context biological variations between individuals may be of importance and the influence of such factors as age and genotype on the radiation response are considered. In cases of partial body exposure, there are a variety of biological factors that may have a considerable influence on the yields of aberrations measured in cells removed from the body shortly after exposure. Factors that are important include: the proportions of lymphocytes located in or passing through the radiation field at the time of exposure; the distribution and mobility of lymphocytes between peripheral blood and the lymphoid systems; differences in the radiation response of lymphocytes of differing types, and differences in the capacities of irradiated and non

  16. Developments in biological dosimetry for the nuclear industry

    International Nuclear Information System (INIS)

    The purpose of this program is to develop methods for providing estimates of radiation exposure based on changes in the cells/tissues of exposed individuals. This work arises from the need for independent measures of exposure of workers when standard dose measurements are unavailable or questionable. The radiation-induced changes that we propose to measure have been correlated with carcinogenesis. It follows that the methods used should also provide indications of the likely biological consequences of radiation exposure for an individual. The consequences of radiation exposure lie in the resolution of the radiation effects at the cellular level. Accordingly, it is at the cellular level that our attention is directed. More precisely, since the consequences of most concern, cancer induction and the induction of inherited diseases, are the result of changes to the genetic material of cells (the DNA), it is the measurement of effects on DNA that are being investigated as possible dose meters. Individuals are unique in terms of their DNA and differ in their cellular capacities to repair the damage from an ionizing radiation dose. Because of these features, not only do biological dosimetry tools offer us a means of measuring a dose at the individual level but may also provide us with a measure of the ultimate risk associated with a given exposure. (author). 7 refs., 2 tabs., 4 figs

  17. Usefulness and limits of biological dosimetry based on cytogenetic methods

    International Nuclear Information System (INIS)

    Damage from occupational or accidental exposure to ionising radiation is often assessed by monitoring chromosome aberrations in peripheral blood lymphocytes, and these procedures have, in several cases, assisted physicians in the management of irradiated persons. Thereby, circulating lymphocytes, which are in the G0 stage of the cell cycle are stimulated with a mitogenic agent, usually phytohaemagglutinin, to replicate in vitro their DNA and enter cell division, and are then observed for abnormalities. Comparison with dose response relationships obtained in vitro allows an estimate of exposure based on scoring: - Unstable aberrations by the conventional, well-established analysis of metaphases for chromosome abnormalities or for micronuclei; - So-called stable aberrations by the classical G-banding (Giemsa-Stain-banding) technique or by the more recently developed fluorescent in situ hybridisation (FISH) method using fluorescent-labelled probes for centromeres and chromosomes. Three factors need to be considered in applying such biological dosimetry: (1) Radiation doses in the body are often inhomogeneous. A comparison of the distribution of the observed aberrations among with that expected from a normal poisson distribution can allow conclusions to be made with regard to the inhomogeneity of exposure by means of the so-called contaminated poisson distribution method; however, its application requires a sufficiently large number of aberrations, i.e. an exposure to a rather large dose at a high dose rate. (2) Exposure can occur at a low dose rate (e.g. from spread or lost radioactive sources) rendering a comparison with in vitro exposure hazardous. Dose-effect relationships of most aberrations that were scored, such as translocations, follow a square law. Repair intervening during exposure reduces the quadratic component with decreasing dose rate as exposure is spread over a longer period of time. No valid solution for this problem has yet been developed, although

  18. Usefulness and limits of biological dosimetry based on cytogenetic methods.

    Science.gov (United States)

    Léonard, A; Rueff, J; Gerber, G B; Léonard, E D

    2005-01-01

    Damage from occupational or accidental exposure to ionising radiation is often assessed by monitoring chromosome aberrations in peripheral blood lymphocytes, and these procedures have, in several cases, assisted physicians in the management of irradiated persons. Thereby, circulating lymphocytes, which are in the G0 stage of the cell cycle are stimulated with a mitogenic agent, usually phytohaemagglutinin, to replicate in vitro their DNA and enter cell division, and are then observed for abnormalities. Comparison with dose-response relationships obtained in vitro allows an estimate of exposure based on scoring: Unstable aberrations by the conventional, well-established analysis of metaphases for chromosome abnormalities or for micronuclei; So-called stable aberrations by the classical G-banding (Giemsa-Stain-banding) technique or by the more recently developed fluorescent in situ hybridisation (FISH) method using fluorescent-labelled probes for centromeres and chromosomes. Three factors need to be considered in applying such biological dosimetry: (1) Radiation doses in the body are often inhomogeneous. A comparison of the distribution of the observed aberrations among cells with that expected from a normal poisson distribution can allow conclusions to be made with regard to the inhomogeneity of exposure by means of the so-called contaminated poisson distribution method; however, its application requires a sufficiently large number of aberrations, i.e. an exposure to a rather large dose at a high dose rate. (2) Exposure can occur at a low dose rate (e.g. from spread or lost radioactive sources) rendering a comparison with in vitro exposure hazardous. Dose-effect relationships of most aberrations that were scored, such as translocations, follow a square law. Repair intervening during exposure reduces the quadratic component with decreasing dose rate as exposure is spread over a longer period of time. No valid solution for this problem has yet been developed, although

  19. Transient impedance changes in venous endothelial monolayers as a biological radiation dosimetry response

    Directory of Open Access Journals (Sweden)

    Erik Fossum Young

    2012-10-01

    Full Text Available In March of 2011, a magnitude 9.0 earthquake and subsequent 14 m-high tsunami caused major damage to the Fukushima Daiichi nuclear power plant in Japan.  While cancer incidence in the radiation-exposed population is a logical concern, the complex effects of radiation on the heart and cardiovascular system are also of interest.  Immediate and early vascular radiation effects could be exploited as a dosimetry modality.  To test whether non-coronary vasculature exhibited transient perturbation in barrier function, video microscopy studies and Electric Cell Substrate Impedance Sensing technology were used to probe very subtle changes in primary human vascular endothelium.  Human umbilical vein endothelial cell (HUVEC monolayers exhibit a transient, statistically significant decrease (P = 0.017 in monolayer resistance 3 h after irradiation with 5.0 Gy of g rays.  Radiation induced perturbations in HUVEC monolayer permeability are similar in magnitude and kinetics to those observed in coronary arterial endothelium.  Therefore, at least two types of vasculature respond to radiation on ECIS arrays with an early transient disruption in permeability.  The finding supports the use of early passage HUVECs for use in bioelectric dosimetry studies of vasculature and suggests that permeability of vessels could potentially serve as a biological dosimetry tool.

  20. Methods of biological dosimetry employing chromosome-specific staining

    Science.gov (United States)

    Gray, Joe W.; Pinkel, Daniel

    2000-01-01

    Methods and compositions for staining based upon nucleic acid sequence that employ nucleic acid probes are provided. Said methods produce staining patterns that can be tailored for specific cytogenetic analyses. Said probes are appropriate for in situ hybridization and stain both interphase and metaphase chromosomal material with reliable signals. The nucleic acid probes are typically of a complexity greater than 50 kb, the complexity depending upon the cytogenetic application. Methods are provided to disable the hybridization capacity of shared, high copy repetitive sequences and/or remove such sequences to provide for useful contrast. Still further methods are provided to produce chromosome-specific staining reagents which are made specific to the targeted chromosomal material, which can be one or more whole chromosomes, one or more regions on one or more chromosomes, subsets of chromosomes and/or the entire genome. Probes and test kits are provided for use in tumor cytogenetics, in the detection of disease related loci, in analysis of structural abnormalities, such as translocations, and for biological dosimetry. Further, methods and prenatal test kits are provided to stain targeted chromosomal material of fetal cells, including fetal cells obtained from maternal blood. Still further, the invention provides for automated means to detect and analyse chromosomal abnormalities.

  1. Present Status and Prospects for Biological Dosimetry using Chromosome Aberration Analysis (invited paper)

    Energy Technology Data Exchange (ETDEWEB)

    Jin, C.Z.; Liu, X.L.; Zhang, Z.Y.; Luo, Y.S

    1998-07-01

    Biological dosimetry of radiation exposures was performed in 21 persons who received an overexposure to radiation in several radiation accidents during 1980-1996 in China. Based on the frequencies of dicentrics and rings the individual dose was estimated. Long-term follow-up studies have been carried out on five of the moderate and high dose exposed victims. The automated karyotype analysis system and the FISH technique have been established. The application of FISH for a dose-response relationship for translocations after irradiation with {sup 60}Co {gamma} rays has been performed. (author)

  2. The FISH chromosome painting technique in Biological Dosimetry : Evolution and applicability

    International Nuclear Information System (INIS)

    The capacity of ionising radiation to induce chromosomal aberrations has been used during decades to assess doses in persons accidentally exposed, giving rise to the discipline Biological Dosimetry. the Biological Dosimetry is a complement to the physical methods of dosimetry and in the situations where those are not available represent the only way to asses the doses received. During decades biological dosimetry has used the dicentric score to determine doses, since a good correlation between in vitro and in vivo irradiation results exists and the background yields are low. However, dicentrics yields decrease with time after irradiation. The translocations and insertions represent stable aberrations what means that they do not decrease in further cell divisions. The development at the end of the 80s of the FISH technique (Fluorescence In Situ Hybridization), represented a great step for the applicability of translocations score for biological dosimetry. In this paper, a review of the FISH chromosome painting technique is presented, addressing the facts that have needed to be solve before its routine use in retrospective dosimetry, as well as the aspects that will need further research in the near future. (Author) 54 refs

  3. Physical and biological dosimetry for risk perception in radioprotection

    Directory of Open Access Journals (Sweden)

    Ademir Amaral

    2005-10-01

    Full Text Available The increase in ionizing radiation (IR applications, especially nuclear, has been followed by the growth of public concern for the potential associated risks. The public’s perception of such risks is often based on the philosophy that IR is harmful at any exposure level. On the other hand, although radiation workers have knowledge about the nature of IR and its potential health effects, the relationship between absorbed dose and risk is not well understood, principally for low doses. This report presents an overview of physical and biological dosimetry as complementary methodologies, as well as their possible contribution for improving risk perception in radioprotection.O crescente aumento das aplicações das radiações ionizantes, em particular as radiações de origem nuclear, tem sido acompanhado pelo aumento do interesse público em relação aos riscos associados a essas aplicações. A percepção de tais riscos por parte da população é freqüentemente baseada na filosofia que a radiação ionizante é perigosa independentemente dos níveis de exposição. Por outro lado, apesar dos trabalhadores ocupacionalmente expostos terem conhecimento da natureza da IR e seus possíveis efeitos á saúde, a relação entre dose absorvida e risco não é bem entendida por estes, em particular para baixos valores de dose. Este artigo resume aspectos da dosimetria física e biológica como metodologias complementares na melhoria da percepção dos riscos em radioproteção.

  4. Effect of contrast agent administration on consequences of dosimetry and biology in radiotherapy planning

    Energy Technology Data Exchange (ETDEWEB)

    Lo, Ching-Jung [Department of Medical Imaging and Radiological Sciences, College of Medicine, Chang Gung University, 259 Wen-Hua 1st Road, Kwei-Shan, Tao-Yuan 333 Taiwan (China); Department of Radiation Oncology, Chang Gung Memorial Hospital, Kwei-Shan, Tao-Yuan 333 Taiwan (China); Yang, Pei-Ying [Department of Medical Imaging and Radiological Sciences, College of Medicine, Chang Gung University, 259 Wen-Hua 1st Road, Kwei-Shan, Tao-Yuan 333 Taiwan (China); Chao, Tsi-Chian, E-mail: chaot@mail.cgu.edu.tw [Department of Medical Imaging and Radiological Sciences, College of Medicine, Chang Gung University, 259 Wen-Hua 1st Road, Kwei-Shan, Tao-Yuan 333 Taiwan (China); Tu, Shu-Ju, E-mail: sjtu@mail.cgu.edu.tw [Department of Medical Imaging and Radiological Sciences, College of Medicine, Chang Gung University, 259 Wen-Hua 1st Road, Kwei-Shan, Tao-Yuan 333 Taiwan (China)

    2015-06-01

    In the treatment planning of radiation therapy, patients may be administrated with contrast media in CT scanning to assist physicians for accurate delineation of the target or organs. However, contrast media are not used in patients during the treatment delivery. In particular, contrast media contain materials with high atomic numbers and dosimetric variations may occur between scenarios where contrast media are present in treatment planning and absent in treatment delivery. In this study we evaluate the effect of contrast media on the dosimetry and biological consequence. An analytical phantom based on AAPM TG 119 and five sets of CT images from clinical patients are included. Different techniques of treatment planning are considered, including 1-field AP, 2-field AP+PA, 4-field box, 7-field IMRT, and RapidArc. RapidArc is a recent technique of volumetric modulated arc therapy and is used in our study of contrast media in clinical scenarios. The effect of RapidArc on dosimetry and biological consequence for administration of contrast media in radiotherapy is not discussed previously in literature. It is shown that dose difference is reduced as the number of external beams is increased, suggesting RapidArc may be favored to be used in the treatment planning enhanced by contrast media. Linear trend lines are fitted for assessment of percent dose differences in the planning target volume versus concentrations of contrast media between plans where contrast media are present and absent, respectively.

  5. Effect of contrast agent administration on consequences of dosimetry and biology in radiotherapy planning

    International Nuclear Information System (INIS)

    In the treatment planning of radiation therapy, patients may be administrated with contrast media in CT scanning to assist physicians for accurate delineation of the target or organs. However, contrast media are not used in patients during the treatment delivery. In particular, contrast media contain materials with high atomic numbers and dosimetric variations may occur between scenarios where contrast media are present in treatment planning and absent in treatment delivery. In this study we evaluate the effect of contrast media on the dosimetry and biological consequence. An analytical phantom based on AAPM TG 119 and five sets of CT images from clinical patients are included. Different techniques of treatment planning are considered, including 1-field AP, 2-field AP+PA, 4-field box, 7-field IMRT, and RapidArc. RapidArc is a recent technique of volumetric modulated arc therapy and is used in our study of contrast media in clinical scenarios. The effect of RapidArc on dosimetry and biological consequence for administration of contrast media in radiotherapy is not discussed previously in literature. It is shown that dose difference is reduced as the number of external beams is increased, suggesting RapidArc may be favored to be used in the treatment planning enhanced by contrast media. Linear trend lines are fitted for assessment of percent dose differences in the planning target volume versus concentrations of contrast media between plans where contrast media are present and absent, respectively

  6. Advances in dosimetry and biological predictors of radiation-induced esophagitis

    Directory of Open Access Journals (Sweden)

    Yu Y

    2016-01-01

    Full Text Available Yang Yu,1 Hui Guan,1 Yuanli Dong,1 Ligang Xing,2 Xiaolin Li2 1School of Medicine and Life Sciences, Shandong Academy of Medical Sciences, University of Jinan, Jinan, 2Department of Radiation Oncology, Shandong Cancer Hospital, Jinan, Shandong Province, People’s Republic of China Objective: To summarize the research progress about the dosimetry and biological predictors of radiation-induced esophagitis.Methods: We performed a systematic literature review addressing radiation esophagitis in the treatment of lung cancer published between January 2009 and May 2015 in the PubMed full-text database index systems.Results: Twenty-eight eligible documents were included in the final analysis. Many clinical factors were related to the risk of radiation esophagitis, such as elder patients, concurrent chemoradiotherapy, and the intense radiotherapy regimen (hyperfractionated radiotherapy or stereotactic body radiotherapy. The parameters including Dmax, Dmean, V20, V30, V50, and V55 may be valuable in predicting the occurrence of radiation esophagitis in patients receiving concurrent chemoradiotherapy. Genetic variants in inflammation-related genes are also associated with radiation-induced toxicity.Conclusion: Dosimetry and biological factors of radiation-induced esophagitis provide clinical information to decrease its occurrence and grade during radiotherapy. More prospective studies are warranted to confirm their prediction efficacy. Keywords: lung cancer, esophagitis, radiation injuries, predictors

  7. Internal dosimetry for epidemiologic studies

    International Nuclear Information System (INIS)

    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

  8. Evaluation of the prematurely condensed chromosome technique for biological dosimetry purposes

    International Nuclear Information System (INIS)

    Unstable chromosome aberrations in mitogen-stimulated peripheral blood lymphocytes are usually scored in biological dosimetry following ionising radiation exposure. Prematurely Condensed Chromosome (PCC) technique, on the other hand, allows the direct observation of chromosomal damage so overcoming the problem of cell culture. Although most often used to study repair mechanisms, il appears a possible alternative for biological dosimetry purposes. This study presents an adaptation of the PCC technique, for the problem of radiological accident. Human blood samples were exposed in vitro to cobalt-60 (O.5 Gy.min-1) between 0 and 4 Gy and excess PCC fragments in lymphocytes were scored at different post-irradiation time of 0,4, and 24 h. As expected, linear dose-effect relationships were obtained for each experimental condition. The excess PCC fragments yield is progressively reduced up to 80 % after one day. These consequences of repair phenomena are crucial in biological expertise, because in our experience blood samples are received at least on day after suspicion of overexposure. As well as conventional cyto-genetics, technique precision depends on the number of scored cells and the range of dose irradiation: 95 % confidence limits interval varies from 0.58 Gy (for a dose assessment of 1 Gy) to 1.02 Gy (for a dose assessment of 4 Gy) when 150 cells are observed after 24 hours repair. Because the time delay needed to obtain preparations to analyse is shorter, PCC technique appears quicker than conventional cyto-genetics. So, we propose this adapted protocol to use PCC fragment yield as biological indicator for assessment of irradiation dose when the date of blood sampling is known and does not exceed 24 h. (authors)

  9. EPR Dosimetry: an update and prospective studies

    International Nuclear Information System (INIS)

    kGy for thermal neutron flux. The radiation induced radical signal was found to be stable over a period of 300 days with marginal fading of 2C2O4: Na2C2O4 mixture as the potential neutron dosimeter for high range dosimetry. The effect of gamma dose irradiation on sodium succinate was studied by EPR technique. It was observed that the radiation induced CO3- radical (g = 2.00357) as linear in signal - dose response, in 35 Gy - 4.4 kGy. Thus, sodium succinate powder samples could be used in EPR dosimetry, since CO3- radicals have been found stable for more than 6 months, post-irradiation. Solid State Nuclear Track Detector (SSNTD) material Tuffak polycarbonate film was studied for prospective EPR dosimetry, feasibility studies were carried out on gamma irradiated SSNTD film. The first derivative EPR spectra of irradiated Tuffak polycarbonate samples contained a singlet, signal at g = 2.00415. The signal was identified as CO33- from earlier reports. The EPR signal intensity of CO33- (g = 2.00415) was found linear in signal - dose response in 10 - 80 kGy. The present paper gives an update of newer EPR dosimetric materials that have been investigated, after a brief introduction to the basic principles of EPR. Further, prospective dosimetric materials with their suitability for applications in EPR dosimetry have been discussed. (author)

  10. Dosimetry using environmental and biological materials. Final report

    Energy Technology Data Exchange (ETDEWEB)

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

    1998-02-01

    This report summarizes a five year effort to improve the sensitivity and reliability of retrospective dosimetry methods, to collaborate with laboratories engaged in related research and to share the technology with startup laboratories seeking similar capabilities. This research program has focused on validation of electron paramagnetic resonance (EPR) as a dosimetry tool and on optimization of the technique by reducing the lower limits of detection, simplifying the process of sample preparation and analysis and speeding analysis to allow greater throughput in routine measurement situations. The authors have investigated the dosimetric signal of hard tissues in enamel, deorganified dentin, synthetic carbonated apatites and synthetic hydroxyapatite. This research has resulted in a total of 27 manuscripts which have been published, are in press, or have been submitted for publication. Of these manuscripts, 14 are included in this report and were indexed separately for inclusion in the data base.

  11. Dosimetry using environmental and biological materials. Final report

    International Nuclear Information System (INIS)

    This report summarizes a five year effort to improve the sensitivity and reliability of retrospective dosimetry methods, to collaborate with laboratories engaged in related research and to share the technology with startup laboratories seeking similar capabilities. This research program has focused on validation of electron paramagnetic resonance (EPR) as a dosimetry tool and on optimization of the technique by reducing the lower limits of detection, simplifying the process of sample preparation and analysis and speeding analysis to allow greater throughput in routine measurement situations. The authors have investigated the dosimetric signal of hard tissues in enamel, deorganified dentin, synthetic carbonated apatites and synthetic hydroxyapatite. This research has resulted in a total of 27 manuscripts which have been published, are in press, or have been submitted for publication. Of these manuscripts, 14 are included in this report and were indexed separately for inclusion in the data base

  12. Report of the workshop on biological dosimetry: Increasing capacity for emergency response

    International Nuclear Information System (INIS)

    Recent events have brought increased attention to the possibility and dangers of a radiological terrorist threat and its potential implication on the national capacity for radiation accident preparedness. In such an event, there is a pressing need to rapidly identify severely irradiated individuals who require prompt medical attention from those who have not been exposed or have been subject to low doses. Initial dose assessment is a key component in rapid triage and treatment, however, the development of accurate methods for rapid dose assessment remains a challenge. In this report, the authors describe a recent workshop supported by the Chemical, Biological, Radiological-Nuclear and Explosives Research and Technology Initiative regarding the international effort to increase biological dosimetry capacity to effectively mount an emergency response in a mass casualty situation. Specifically, the focus of the workshop was on the current state of biological dosimetry capabilities and capacities in North America, recent developments towards increasing throughput for biological dosimetry and to identify opportunities for developing a North American Biological Dosimetry Network and forming partnerships and collaborations within Canada and the USA. (authors)

  13. Physical and biological dosimetry at the RA-3 facility for small animal irradiation: preliminary BNCT studies in an experimental model of oral cancer

    International Nuclear Information System (INIS)

    Boron Neutron Capture Therapy (BNCT) is a binary treatment modality based on the capture reaction that occurs between thermal neutrons and boron-10 atoms that accumulate selectively in tumor tissue, emitting high linear energy transfer (LET), short range (5-9 microns) particles (alpha y 7Li). Thus, BNCT would potentially target tumor tissue selectively, sparing normal tissue. Herein we evaluated the feasibility of treating experimental oral mucosa tumors with BNCT at RA-3 (CAE) employing the hamster cheek pouch oral cancer model and characterized the irradiation field at the RA-3 facility. We evaluated the therapeutic effect on tumor of BNCT mediated by BPA in the hamster cheek pouch oral cancer model and the potential radio toxic effects in normal tissue. We evidenced a moderate biological response in tumor, with no radio toxic effects in normal tissue following irradiations with no shielding for the animal body. Given the sub-optimal therapeutic response, we designed and built a 6Li2CO3 shielding for the body of the animal to increase the irradiation dose to tumor, without exceeding normal tissue radio tolerance. The measured absolute magnitude of thermal neutron flux and the characterization of the beam with and without the shielding in place, suggest that the irradiation facility in the thermal column of RA-3 would afford an excellent platform to perform BNCT studies in vitro and in vivo in small experimental animals. The present findings must be confirmed and extended by performing in vivo BNCT radiobiological studies in small experimental animals, employing the shielding device for the animal body. (author)

  14. Biological dosimetry applied to treatment with 131 radio-iodine in thyroid cancers

    International Nuclear Information System (INIS)

    This study had 2 objectives: Firstly to compare the number of unstable chromosomal anomalies (dicentrics, rings and fragments) obtained by the method of conventional cytogenetics with the number of translocations revealed by in situ hybridization (FISH) and secondly to estimate the mean whole body dose after treatment with 3.7 GBq (100 mCi) of 131I. The estimated mean total body dose is 2 to 4 times higher than that based on MIRD calculations (0.13 Gy). In fact, MIRD calculations were derived from individuals with normal thyroid function and normal metabolic activity. Thyroid cancer patients are hypothyroid at the time of 131I administration. The hypothyroid status decreases the renal clearance of radioiodine and thus increases the whole body dose which can explain the discrepancy between the MIRD estimation and the values found by biological dosimetry. (author)

  15. Activation methods of retrospective dosimetry using biological samples

    International Nuclear Information System (INIS)

    23Na and 32S are stable isotopes which are present in humans - 23Na in blood and other tissues, 32S in hair. When human body is irradiated by neutrons, nuclear reactions 23Na(n,γ)24Na and 32S(n,p)32P occur, the products, 24Na and 32P, being radioactive. The induced activity can be used for retrospective assessment of the neutron dose. The principle of this dosimetry application is described. As a particular case, the relations between the activity and neutron dose were derived for irradiation of a human by the fission neutron spectrum. (orig.)

  16. From imaging to dosimetry: GEANT4-based study on the application of Medipix to neutron dosimetry

    International Nuclear Information System (INIS)

    An application of Medipix2 using a newly developed segmented multiple thickness polyethylene (PE) converter for fast neutron detection is presented. The system has the ability to provide an energy independent response for the dose equivalent for fast neutrons. The application of weighting factors to each defined thickness of PE allows for a flattening of the response of the detector system for dosimetry applications. Six PE converter segments were applied, and their thicknesses and weighting factors were optimised to obtain the required energy independent detector response. The study performed by means of GEANT4. Its suitability for neutron dosimetry was studied with respect to a previously published work.

  17. From imaging to dosimetry: GEANT4-based study on the application of Medipix to neutron dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Othman, M.A.R. [Centre for Medical Radiation Physics, University of Wollongong, Northfield Ave, Wollongong 2522, N.S.W. (Australia); Marinaro, D.G. [Defence Science and Technology Organisation, 506 Lorimer St, Fishermans Bend, VIC 3207 (Australia); Petasecca, M.; Guatelli, S.; Cutajar, D.L.; Lerch, M.L.F. [Centre for Medical Radiation Physics, University of Wollongong, Northfield Ave, Wollongong 2522, N.S.W. (Australia); Prokopovich, D.A.; Reinhard, M.I. [Centre for Medical Radiation Physics, University of Wollongong, Northfield Ave, Wollongong 2522, N.S.W. (Australia); ANSTO, New Illawarra Road, Lucas Heights, NSW (Australia); Uher, J. [CSIRO Process Science and Engineering, New Illawarra Road, Lucas Heights, NSW 2234 (Australia); Jakubek, J.; Pospisil, S. [Institute of Experimental and Applied Physics, Czech Technical University in Prague, 12800 Prague 2 (Czech Republic); Rosenfeld, A.B., E-mail: anatoly@uow.edu.a [Centre for Medical Radiation Physics, University of Wollongong, Northfield Ave, Wollongong 2522, N.S.W. (Australia)

    2010-12-15

    An application of Medipix2 using a newly developed segmented multiple thickness polyethylene (PE) converter for fast neutron detection is presented. The system has the ability to provide an energy independent response for the dose equivalent for fast neutrons. The application of weighting factors to each defined thickness of PE allows for a flattening of the response of the detector system for dosimetry applications. Six PE converter segments were applied, and their thicknesses and weighting factors were optimised to obtain the required energy independent detector response. The study performed by means of GEANT4. Its suitability for neutron dosimetry was studied with respect to a previously published work.

  18. Standards in biological dosimetry: A requirement to perform an appropriate dose assessment.

    Science.gov (United States)

    Voisin, Philippe

    2015-11-01

    Every year, many countries perform a significant number of investigations based on biological radiation dose assessment to check suspected or true overexposure by irradiation of radiation workers and individuals of the general population. The scoring of dicentrics in peripheral blood lymphocytes has gradually become the "gold standard" for the biodosimetry-based assessment of accidental situations. Nevertheless, other "classical" biodosimetric methods such as micronuclei, prematurely condensed chromosomes (PCC) and FISH translocations are relevant in some exposure situations, also for surveillance of groups of populations at risk. Historical international intercomparison studies have shown discrepancies among dose-effect curves used to estimate doses from blood samples irradiated between 0 and 4Gy. Recent experimental work performed by the biological dosimetry laboratory of the French Institute for Radiation Protection and Nuclear Safety (IRSN) has shown the impact of some blood harvesting parameters on the mitotic index, and consequently on the quality of dose assessment. Therefore, it was relevant to define the best Quality Assurance (QA) and Quality Control (QC) criteria to harmonize protocols among biodosimetry laboratories. Complementary with several editions of an IAEA technical manual, ISO standards were written with the view of considering the most used chromosome aberrations assays: dicentrics and micronuclei. An important feature of these standards is to address the organization of population triage and laboratories networking that would be required in case of a large nuclear event or malicious act involving radioactive material. These ISO standards are relevant and helpful to implement a coordinated response of several biodosimetry networks in Europe, Japan, Canada, and to support European programs such as MULTIBIODOSE and RENEB. A new important ISO standard on the use of FISH translocations in retrospective dosimetry is now being drafted. PMID:26520381

  19. Analysis and assessment of the detriment in interventional radiology using biological dosimetry methods

    Energy Technology Data Exchange (ETDEWEB)

    Montoro, A.; Almonacid, M.; Villaescusa, J.I. [Hospital Univ. la Fe de Valen cian, Servicio de Proteccion Radiologica, Valencia (Spain); Barquinero, J.F.; Rodriguez, P. [Universitat Autonom a de Barcelona, Servicio de Dosimetria Biologica, Unidad de Antropologia, Departamento de Biologia Animal, Vegetal y Ecologia., Barcelona (Spain); Barrios, L. [Universidad Autonoma de Barcelona, Dept. de Biologia Celular y Fisiologia. Unidad de Biologia Celular, Barcelona (Spain); Verdu, G.; Ramos, M. [Universidad Politecnica de Valencia, Dept. de Ingenieria Quimica y Nuclear, Valencia, (Spain)

    2006-07-01

    Interventional radiologist and staff members usually are exposed to high levels of scattered radiation. As a result, the exposition to radiation procedures can produce detrimental effects that we would have to know. Effective dose is the quantity that better estimates the radiation risk. For this study we have realized an estimation of the radiological detriment to exposed workers of the Hospital la Fe de Valencia. For it, have been used physical doses registered in detectors T.L.D., and doses estimated by biological dosimetry in lymphocytes of peripheral blood. There has been estimated for every case the probability of effect of skin cancer and of non-solid cancers (leukaemia, lymphoma and myeloma), being compared with the baseline probability of natural effect. Biological doses were obtained by extrapolating the yield of dicentrics and translocations to their respective dose -effect curves. The discrepancies observed between physically recorded doses and biological estimated doses indicate that workers did not always wear their dosimeters or the dosimeters were not always in the radiation field. Cytogenetic studies should be extended to more workers to assess the risk derived from their occupational exposure. (authors)

  20. Analysis and assessment of the detriment in interventional radiology using biological dosimetry methods

    International Nuclear Information System (INIS)

    Interventional radiologist and staff members usually are exposed to high levels of scattered radiation. As a result, the exposition to radiation procedures can produce detrimental effects that we would have to know. Effective dose is the quantity that better estimates the radiation risk. For this study we have realized an estimation of the radiological detriment to exposed workers of the Hospital la Fe de Valencia. For it, have been used physical doses registered in detectors T.L.D., and doses estimated by biological dosimetry in lymphocytes of peripheral blood. There has been estimated for every case the probability of effect of skin cancer and of non-solid cancers (leukaemia, lymphoma and myeloma), being compared with the baseline probability of natural effect. Biological doses were obtained by extrapolating the yield of dicentrics and translocations to their respective dose -effect curves. The discrepancies observed between physically recorded doses and biological estimated doses indicate that workers did not always wear their dosimeters or the dosimeters were not always in the radiation field. Cytogenetic studies should be extended to more workers to assess the risk derived from their occupational exposure. (authors)

  1. Latin-American Biological Dosimetry Network (LBDNET) Intercomparison Exercise. Evaluation through triage and conventional scoring criteria. Development of a new approach for statistical data analysis

    International Nuclear Information System (INIS)

    Biological Dosimetry is a necessary support for National Radiation Protection Programs and Emergency Response Schemes. A Latin-American Biological Dosimetry Network (LBDNET) has been constituted by the biological dosimetry laboratories from: Argentina, Brazil, Chile, Cuba, Mexico, Peru, and Uruguay (IAEA Regional Project RLA9/054, 2007). The biological dosimetry laboratory of Argentina organized an international biological dosimetry intercomparison for the analysis of some relevant parameters involved in dose assessment, to reinforce the response capability in accidental situations requiring the activation of mutual assistance mechanisms and thus, constituting the bases of the LBDNET organization. (authors)

  2. Beta-dosimetry studies at LLNL

    International Nuclear Information System (INIS)

    This paper summarizes three beta-dosimetry studies made recently at the Lawrence Livermore National Laboratory. The first study was to determine the beta-gamma exposure rates at the Los Alamos Godiva IV Critical Assembly. The beta spectra from the assembly were evaluated using absorption curves and the beta-gamma dose-rate ratios were determined at various distances from the assembly. A comparison was made of the doses determined using two types of TLD personnel dosimeters and a film badge. The readings of an Eberline RO-7 instrument and the dose rates determined by TLDs were compared. Shielding provided by various metals, gloves, and clothing were measured. The second study was to determine the beta energy response of the Eberline RO-7 instrument based on measurements made with the PTB beta sources. This study required additional calibration points for the PTB sources which were made using extrapolation chamber measurements. The third study resulted in two techniques to determine the beta energy (E/sub max/) from the readings of this-window portable survey instruments. Both techniques are based on the readings obtained using aluminium filters. One technique is for field application, requires one filter, and provides a quick estimate of the beta energy in three energy groups: 1.5 MeV. The second technique is more complex requiring measurements with two or three filters, but gives the beta energy and the approximate shape of the beta spectrum. 9 references, 6 figures

  3. 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;

    A comparison of dosimetry methods at different clinics can be used as a means to uncover systematic uncertainties in ra-diotherapy. To assess the current status of reference dosimetry and small-field dosimetry in clinical practice, a collaborative compari-son study involving several dosimetry...... methods was performed by DTU Nutech at six Danish clinics. The first part of the intercompa-rison regarded the consistency of reference dosimetry. Absorbed dose to water under reference conditions was measured using a Farmer ionization chamber, and was found to agree within 1 % with the daily dose checks...... obtained routinely at each clinic. The second part of the study concerned the accuracy of small-field dosimetry and dose calculations. The geometric size of small fields down to 1 cm x 1 cm was measured using radiochromic film. Minor discre-pancies were seen between the nominal field sizes set by the colli...

  4. 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,

  5. General guidelines for safe and expeditious international transport of samples subjected to biological dosimetry assessment

    International Nuclear Information System (INIS)

    It has been observed that victims of accidental overexposures show better chance of survival if they receive medical treatment early. The increased risk of scenarios involving mass casualties has stimulated the scientific community to develop tools that would help the medical doctors to treat victims. The biological dosimetry has become a routine test to estimate the dose, supplementing physical and clinical dosimetry. In case of radiation emergencies, in order to provide timely and effectively biological dosimetry assistance it is essential to guarantee an adequate transport of blood samples in principal, for providing support to countries that do not have bio-dosimetry laboratories. The objective of the present paper is to provide general guidelines, summarised in 10 points, for timely and proper receiving and sending of blood samples under National and International regulations, for safe and expeditious international transport. These guidelines cover the classification, packaging, marking, labelling, refrigeration and documentation requirements for the international shipping of blood samples and pellets, to provide assistance missions with a tool that would contribute with the preparedness for an effective bio-dosimetric response in cases of radiological or nuclear emergencies. (authors)

  6. Activities developed by the biological dosimetry laboratory of the Autoridad Regulatoria Nuclear - ARN of Argentina

    International Nuclear Information System (INIS)

    Biological dosimetry (DB) allows to estimate doses absorbed in individuals exposed to ionizing radiation through the quantification of stable and unstable chromosome aberrations (SCA and UCA). The frequency of these aberrations is referred to a calibration dose response curve (in vitro) to determine the doses of the individual to the whole body. The DB is a necessary support for programs of national radiation protection and response systems in nuclear or radiological emergencies in the event of accidental or incidental, single overexposure or large scale. In this context the Laboratory of Dosimetry Biological (LDB) of the Authority Regulatory Nuclear (ARN) Argentina develops and applies different dosimeters cytogenetic from four decades ago. These dosimeters provide a fact more within the whole of the information necessary for an accidental, complementing the physical and clinical dosimetry exposure assessment. The most widely used in the DB biodosimetric method is the quantification of SCA (dicentrics and rings Central) from a sample of venous blood. The LDB is accredited for the trial, under rules IRAM 301: 2005 (ISO / IEC 17025: 2005) and ISO 19238:2004. Test applies to the immediate dosimetry evaluation of acute exposures, all or a large part of the body in the range 0,1-5 Gy. In this context the LDB is part of the Latin American network of DB (LBDNet), BioDoseNet-who and response system in radiological emergencies and nuclear IAEA-RANET, being enabled to summon the LBDNet if necessary

  7. Radiation effects analysis in a group of interventional radiologists using biological and physical dosimetry methods

    Energy Technology Data Exchange (ETDEWEB)

    Ramos, M., E-mail: WEMLmirapas@iqn.upv.e [Department of Chemical and Nuclear Engineering, Polytechnic University of Valencia, Camino de Vera s/n, 46022 Valencia (Spain); Montoro, A.; Almonacid, M. [Radiation Protection Service, Hospital Universitario La Fe Valencia (Spain); Ferrer, S. [Department of Chemical and Nuclear Engineering, Polytechnic University of Valencia, Camino de Vera s/n, 46022 Valencia (Spain); Barquinero, J.F. [Biological Dosimetry Service, Unit of Anthropology, Department of Animal and Vegetable Biology and Ecology, Universitat Autonoma de Barcelona (UAB) (Spain); Tortosa, R. [Radiation Protection Service, Hospital Universitario La Fe Valencia (Spain); Verdu, G. [Department of Chemical and Nuclear Engineering, Polytechnic University of Valencia, Camino de Vera s/n, 46022 Valencia (Spain); Rodriguez, P. [Biological Dosimetry Service, Unit of Anthropology, Department of Animal and Vegetable Biology and Ecology, Universitat Autonoma de Barcelona (UAB) (Spain); Barrios, L.L. [Department of Physiology and Cellular Biology, Unit of Cellular Biology (UAB) (Spain); Villaescusa, J.I. [Radiation Protection Service, Hospital Universitario La Fe Valencia (Spain)

    2010-08-15

    excess radio-induced risk of leukemia in the group under study. Finally, the maximum radiological detriment in the group, evaluated as the total number of radio-induced cancers using physical dosimetry, has been of 2.18/1000 person-year (skin and leukemia), and using biological dosimetry of 9.20/1000 PY (leukemia). As a conclusion, this study has provided an assessment of the non-deterministic effects (rate of radio-induced cancer incidence) attributable to the group under study due to their professional activity.

  8. Biological dosimetry by the triage dicentric chromosome assay - Further validation of international networking

    Energy Technology Data Exchange (ETDEWEB)

    Wilkins, Ruth C., E-mail: Ruth.Wilkins@hc-sc.gc.ca [Health Canada, Ottawa, ON K1A 0K9 (Canada); Romm, Horst; Oestreicher, Ursula [Bundesamt fur Strahlenschutz, 38226 Salzgitter (Germany); Marro, Leonora [Health Canada, Ottawa, ON K1A 0K9 (Canada); Yoshida, Mitsuaki A. [Biological Dosimetry Section, Dept. of Dose Assessment, Research Center for Radiation Emergency Medicine, NIRS, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan); Department Radiation Biology, Institute of Radiation Emergency Medicine, Hirosaki University Graduate School of Health Sciences, 66-1 Hon-cho, Hirosaki, Aomori 036-8564 (Japan); Suto, Y. [Biological Dosimetry Section, Dept. of Dose Assessment, Research Center for Radiation Emergency Medicine, NIRS, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan); Prasanna, Pataje G.S. [National Cancer Institute, Division of Cancer Treatment and Diagnosis, Radiation Research Program, 6130 Executive Blvd., MSC 7440, Bethesda, MD 20892-7440 (United States)

    2011-09-15

    Biological dosimetry is an essential tool for estimating radiation doses received to personnel when physical dosimetry is not available or inadequate. The current preferred biodosimetry method is based on the measurement of radiation-specific dicentric chromosomes in exposed individuals' peripheral blood lymphocytes. However, this method is labor-, time- and expertise-demanding. Consequently, for mass casualty applications, strategies have been developed to increase its throughput. One such strategy is to develop validated cytogenetic biodosimetry laboratory networks, both national and international. In a previous study, the dicentric chromosome assay (DCA) was validated in our cytogenetic biodosimetry network involving five geographically dispersed laboratories. A complementary strategy to further enhance the throughput of the DCA among inter-laboratory networks is to use a triage DCA where dose assessments are made by truncating the labor-demanding and time-consuming metaphase spread analysis to 20 - 50 metaphase spreads instead of routine 500 - 1000 metaphase spread analysis. Our laboratory network also validated this triage DCA, however, these dose estimates were made using calibration curves generated in each laboratory from the blood samples irradiated in a single laboratory. In an emergency situation, dose estimates made using pre-existing calibration curves which may vary according to radiation type and dose rate and therefore influence the assessed dose. Here, we analyze the effect of using a pre-existing calibration curve on assessed dose among our network laboratories. The dose estimates were made by analyzing 1000 metaphase spreads as well as triage quality scoring and compared to actual physical doses applied to the samples for validation. The dose estimates in the laboratory partners were in good agreement with the applied physical doses and determined to be adequate for guidance in the treatment of acute radiation syndrome.

  9. Biological dosimetry in patients with differenced thyroid carcinoma treated with Iodine-131

    International Nuclear Information System (INIS)

    The differentiated thyroid carcinoma (DTC), constitutes the 90 % of the thyroid gland cancers. 80% of patients are cured after the initial therapy and 12% remained disease-free after successive treatments. The 24 patients included in this study represent a sample of the aforementioned 12% and 8%, with recurrence in the first decade post-treatment (local disease and/or recurrence at distance). The internal radiotherapy with 131I in patients with DTC is used within the therapeutic schema as a step post-thyroidectomy. The success of the therapy is to get a lethal dose in the tumor tissue, which depends on the therapeutic activity and the retention of 131I, without exceeding the dose of tolerance in healthy tissues. The most widespread way of administration is the empirical prescription which considers the clinical and laboratory parameters for its determination. In this work, the treatment protocol applied incorporates assessment by biological (DB) and internal (DI) dosimetry for estimating absorbed dose to the whole body and bone marrow to manage a personalized therapeutic dose for each patient. The biological dose estimation is based on the quantification of chromosomal aberrations, which is often referred to a dose-response curve in which lymphocytes are irradiated in vitro with 131I, allowing to determine the dose in vivo of circulating lymphocytes patients

  10. Use of FISH-translocations analyses for retrospective biological dosimetry: How stable are stable chromosome aberrations?

    International Nuclear Information System (INIS)

    Chromosome aberrations, in particular dicentrics, in peripheral blood lymphocytes are used to estimate the absorbed dose immediately following a radiation accident. However, difficulties for dose estimation arise with old exposures, due to a decline of cells containing unstable dicentric aberrations. The fluorescence in situ hybridisation (FISH) technique employing chromosome specific DNA libraries to 'paint' individual human chromosomes has opened new perspectives for rapid and reliable detection of stable chromosome aberrations such as translocations. The inherent stability of translocations over cell generations has enabled them to be used as a biodosemeter. However, due to the limited life of circulating T-lymphocytes, a level of uncertainty exists on the long-term persistence of stable translocations. The objectives of the present work are to present the current state of knowledge on the stability of translocations detected by FISH. The following aspects have been considered; (1) experience so far of retrospective biological dosimetry in humans following accidental and occupational over-exposure, (2) animal studies using mice and monkeys, (3) the influence of subsequent cell divisions on the yield and persistence of translocations following in vitro irradiation of human lymphocytes, and (4) the needs for further work to standardise and validate the use of FISH as a biological dosemeter, and to investigate the influence of various parameters such as radiation quality, dose rate and the discrimination of sub-types of translocations on persistence. (author)

  11. Main activities of the Latin American Network of Biological Dosimetry (LBDNet)

    International Nuclear Information System (INIS)

    The Latin American Biological Dosimetry Network (LBDNET) was constituted in 2007 for mutual assistance in case of a radiation emergency in the region supported by IAEA Technical Cooperation Projects RLA/9/054 and RLA/9/061. The main objectives are: a) to strengthen the technical capacities of Biological Dosimetry Services belonging to laboratories existing in the region (Argentine, Brazil, Chile, Cuba, Mexico, Peru and Uruguay) integrated in National Radiological Emergency Plans to provide a rapid biodosimetric response in a coordinated manner between countries and with RANET-IAEA/BioDoseNet-WHO, b) to provide support to other countries in the region lacking Biological Dosimetry laboratories, c) to consolidate the organization of the Latin American Biological Dosimetry Network for mutual assistance. The activities developed include technical meetings for protocols and chromosomal aberration scoring criteria unification, blood samples cultures exercises, chromosomal aberrations analysis at microscope, discussion of statistical methods and specialized software for dose calculation, the intercomparison between laboratory data after the analysis of slides with irradiated material and the intercomparison of the analysis of captured images distributed electronically in the WEB. The last exercise was the transportation of an irradiated human blood sample to countries inside and outside of the region. At the moment the exercises are concluded and they are pending to be published in reference journals. Results obtained show the capacity in the region for a biodosimetric response to a radiological accident. In the future the network will integrate techniques for high dose exposure evaluation and will enhance the interaction with other emergency systems in the region. (authors)

  12. The Latin American Biological Dosimetry Network (LBDNet): Argentina, Brazil, Chile, Cuba, Mexico, Peru, Uruguay

    International Nuclear Information System (INIS)

    Biological dosimetry is a necessary support for national radiation protection programs and emergency response schemes. The Latin American Biological Dosimetry Network (LBDNet) was formally founded in 2007 for mutual assistance in case of radiation emergencies and for providing support to other Latin American countries that do not have bio dosimetry laboratories. In the frame of the IAEA Technical Cooperation Projects RLA/9/54 and RLA/9/61 the following activities have been performed: a) An international intercomparison exercise organized during 2007-2008 included six European countries and LBDNet laboratories. Relevant parameters related with dose assessment were evaluated through triage and conventional scoring criteria. A new approach for statistical data analysis was developed including assessment of inter-laboratory reproducibility and intra-laboratory repeatability. Overall, the laboratory performance was satisfactory for mutual cooperation purposes. b) In 2009, LBDNet and two European countries carried out a digital image intercomparison exercise involving dose assessment from metaphase images distributed electronically through internet. The main objectives were to evaluate scoring feasibility on metaphase images and time response. In addition a re-examination phase was considered in which the most controversial images were discussed jointly, this allowed for the development of a homogeneous scoring criteria within the network. c) A further exercise was performed during 2009 involving the shipment of biological samples for biological dosimetry assessment. The aim of this exercise was to test the timely and properly sending and receiving blood samples under national and international regulations. A total of 14 laboratories participated in this joint IAEA, PAHO and WHO. (Author)

  13. The Latin American Biological Dosimetry Network (LBDNet): Argentina, Brazil, Chile, Cuba, Mexico, Peru, Uruguay

    Energy Technology Data Exchange (ETDEWEB)

    Guerrero C, C.; Arceo M, C. [ININ, Carretera Mexico-Toluca s/n, Ocoyoacac 52750, Estado de Mexico (Mexico); Di Giorgio, M.; Vallerga, M.; Radl, A. [Autoridad Regulatoria Nuclear, Av. del Libertador 8250, C1429 BNP CABA (Argentina); Taja, M.; Seoane, A.; De Luca, J. [Universidad Nacionald de La Plata, Av. 7 No. 1776, La Plata 1900, Buenos Aires (Argentina); Stuck O, M. [Instituto de Radioproteccion y Dosimetria, Av. Salvador Allende s/n, Recreio dos Bandeirantes, Rio de Janeiro (Brazil); Valdivia, P., E-mail: lbdnet@googlegroups.co [Comision Chilena de Energia, Amutanegui 95, Santiago Centro, Santiago (Chile)

    2010-10-15

    Biological dosimetry is a necessary support for national radiation protection programs and emergency response schemes. The Latin American Biological Dosimetry Network (LBDNet) was formally founded in 2007 for mutual assistance in case of radiation emergencies and for providing support to other Latin American countries that do not have bio dosimetry laboratories. In the frame of the IAEA Technical Cooperation Projects RLA/9/54 and RLA/9/61 the following activities have been performed: a) An international intercomparison exercise organized during 2007-2008 included six European countries and LBDNet laboratories. Relevant parameters related with dose assessment were evaluated through triage and conventional scoring criteria. A new approach for statistical data analysis was developed including assessment of inter-laboratory reproducibility and intra-laboratory repeatability. Overall, the laboratory performance was satisfactory for mutual cooperation purposes. b) In 2009, LBDNet and two European countries carried out a digital image intercomparison exercise involving dose assessment from metaphase images distributed electronically through internet. The main objectives were to evaluate scoring feasibility on metaphase images and time response. In addition a re-examination phase was considered in which the most controversial images were discussed jointly, this allowed for the development of a homogeneous scoring criteria within the network. c) A further exercise was performed during 2009 involving the shipment of biological samples for biological dosimetry assessment. The aim of this exercise was to test the timely and properly sending and receiving blood samples under national and international regulations. A total of 14 laboratories participated in this joint IAEA, PAHO and WHO. (Author)

  14. Tenth ORNL Personnel Dosimetry Intercomparison Study

    Energy Technology Data Exchange (ETDEWEB)

    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 /sup 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. Tenth ORNL Personnel Dosimetry Intercomparison Study

    International Nuclear Information System (INIS)

    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 137Cs 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

  16. Neutron and Gamma Dosimetry in the Biological Cavity of NRX

    International Nuclear Information System (INIS)

    The NRX reactor at Chalk River has been equipped with a biological cavity for the experimental irradiation of biological material with slow neutrons. The high intensity of gamma radiation in the thermal beam is sharply reduced by bismuth shielding (average thickness 18 cm) which entirely surrounds the biological cavity. The internal dimensions of the cavity are 18 cm in height and 10 cm in diameter. The neutrons in the biological cavity are predominantly thermal neutrons, as can be seen from the ratio of captures by gold with and without cadmium (>3000). When the reactor is operating at maximum power, the mean slow-neutron flux is 9 x 108 n/cm2s. The neutron-flux densities are obtained by activating calibrated gold or manganese detectors or else derived from the currents obtained by passing carbon dioxide and nitrogen in turn through a graphite ionization chamber. In the case of prolonged irradiation, the total neutron flux is obtained by measuring the activity of cobalt wires which are placed in the cavity along with the biological specimens that are being irradiated. The mean intensity of the gamma-radiation field in the biological cavity is 145 r/h. This can be further reduced to 95 r/h merely by placing a removable bismuth lining in the cavity, though this of course reduces the available space. The gamma-exposure doses are measured by means of a graphite-CO2 ionization chamber insensitive to thermal neutrons. The gamma radiation and the neutron-flux density vary considerably, depending on the position inside the cavity and inside the organisms that are being irradiated. The various factors which may lead to error when measuring the exposure dose and dose absorbed during irradiation are analysed. (author)

  17. Development of radiation biological dosimetry and treatment of radiation-induced damaged tissue

    International Nuclear Information System (INIS)

    Util 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 apoptotic fragment assay, PCC, comet assay, and micronucleus assay which was the significant relationship between dose and cell damages to evaluate the irradiated dose as correct and rapid as possible using lymphocytes and crypt cells, and compared with chromosome dosimetry and micronucleus assay

  18. Development of radiation biological dosimetry and treatment of radiation-induced damaged tissue

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Chul Koo; Kim, Tae Hwan; Lee, Yun Sil [and others

    2000-04-01

    Util 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 apoptotic fragment assay, PCC, comet assay, and micronucleus assay which was the significant relationship between dose and cell damages to evaluate the irradiated dose as correct and rapid as possible using lymphocytes and crypt cells, and compared with chromosome dosimetry and micronucleus assay.

  19. Development of radiological emergency preparedness and biological dosimetry technology

    Energy Technology Data Exchange (ETDEWEB)

    Han, Moon Hee; Kim, In Gyoo; Kim, Kook Chan; Kim, Eun Han; Suh, Kyung Suk; Hwang, Won Tae; Choi, Young Gil; Shim, Hae Won; Lee, Jeong Ho; Lee, Kang Suk

    1999-04-01

    Large-scale field tracer experiments have been conducted on Ulchin and Wolsung nuclear sites for the purpose of validating FADAS and of analyzing the environmental characteristics around the nuclear site. The most influential factor in atmospheric dispersion is the meteorological condition. During the experiment, meteorological data were measured on the release point and the selected positions among sampling points. Once radioactive materials are released to the atmosphere, members of public may be exposed through the environmental media such as air, soil and foods. Therefore, to protect the public, adequate countermeasures should be taken at due time for those exposure pathways. Both processes of justification and optimization are applied to a countermeasure simultaneously for decision-making. The work scope of biological research for the radiation protection had contained the search of biological microanalytic methods for the assessment of health effect by radiation and toxic agents, the standardization of human t-lymphocyte cell culture and polymerase chain reaction, T-cell clonal assay, and the quantification of mutation frequency in hypoxanthine (guanine) phosphoribosyl transferase (hprt) gene locus by single exposure or combined exposure. Especially, the polymerase chain reaction methods by usage of reverse transcriptase had been developed to analyze of gene product by {gamma} - radiation and chemical (pentachlorophenol) agent exposure, and investigate the point mutation in hprt gene locus of T-lymphocytes. (author)

  20. Development of radiological emergency preparedness and biological dosimetry technology

    International Nuclear Information System (INIS)

    Large-scale field tracer experiments have been conducted on Ulchin and Wolsung nuclear sites for the purpose of validating FADAS and of analyzing the environmental characteristics around the nuclear site. The most influential factor in atmospheric dispersion is the meteorological condition. During the experiment, meteorological data were measured on the release point and the selected positions among sampling points. Once radioactive materials are released to the atmosphere, members of public may be exposed through the environmental media such as air, soil and foods. Therefore, to protect the public, adequate countermeasures should be taken at due time for those exposure pathways. Both processes of justification and optimization are applied to a countermeasure simultaneously for decision-making. The work scope of biological research for the radiation protection had contained the search of biological microanalytic methods for the assessment of health effect by radiation and toxic agents, the standardization of human t-lymphocyte cell culture and polymerase chain reaction, T-cell clonal assay, and the quantification of mutation frequency in hypoxanthine (guanine) phosphoribosyl transferase (hprt) gene locus by single exposure or combined exposure. Especially, the polymerase chain reaction methods by usage of reverse transcriptase had been developed to analyze of gene product by γ - radiation and chemical (pentachlorophenol) agent exposure, and investigate the point mutation in hprt gene locus of T-lymphocytes. (author)

  1. Biological dosimetry, scopes and limitations; Dosimetria biologica, alcances y limitaciones

    Energy Technology Data Exchange (ETDEWEB)

    Guerrero C, C.; Brena V, M. [Departamento de Biologia, Instituto Nacional de Investigaciones Nucleares, C.P. 52045 Salazar, Estado de Mexico (Mexico)

    1999-07-01

    The analysis of the aberrations in chromosomes is an alternative to establish the exposure dose to the radiation, when the information provided by the traditional physical methods is insufficient. There are diverse causes by which it can reached to apply an alternative system, such is the case of exposures of another persons to the management of radiation sources, which not carry physical dosemeter. Contrary case is to the occupational exposure personnel (OEP), what must to utilize some system for determining the exposure dose, even so can be needed the case for more information. In any case, the cells from the affected person are the alternative without the biological system be overlap to the physical, it is complementary. (Author)

  2. Biological dosimetry after a single treatment with 131 radioiodine for differentiated thyroid carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    M`Kacher, R.; Legal, J.D.; Schlumberger, M.; Beron-Gaillard, N.; Gaussen, A.; Parmentier, C.; Aubert, B. [Institut Gustave Roussy, 94 - Villejuif (France)

    1997-03-01

    To determine the cytogenetic and genotoxic risk associated with therapeutic exposure to {sup 131}I (3.7 GBq) in 50 patients with differentiated thyroid carcinoma, we estimated the dosimetric index that reflects the dose to the bone marrow on day 4 and at several time intervals after exposure over a period of 2 years. The dosimetric index is 2 to 4 times higher for the dose to the bone marrow than the results based on MIRD calculations, which are derived from individuals with normal thyroid function and normal metabolic activity. This study shows that chromosomal anomalies induced by radiation persist over long periods of time (2 years) and that a retrospective biological dosimetry can be established in patients exposed to ionizing radiations. Blood samples taken at 3 and 6 months and 1 and 2 years after administration of {sup 131}I demonstrated more reciprocal translocations than those taken at 4 days and the presence of the dicentrics without the `accompagnateur` fragment. Stem cells produce new lymphocytes to make-up for the loss after {sup 131}I treatment. Direct estimation of the dose using our dosimetric index will provide a more accurate quantification of the risk incurred by exposure to {sup 131}I which until now, has been based exclusively on approximate statistical calculations of cumulative {sup 131}I doses. (authors)

  3. Biological dosimetry after a single treatment with 131 radioiodine for differentiated thyroid carcinoma

    International Nuclear Information System (INIS)

    To determine the cytogenetic and genotoxic risk associated with therapeutic exposure to 131I (3.7 GBq) in 50 patients with differentiated thyroid carcinoma, we estimated the dosimetric index that reflects the dose to the bone marrow on day 4 and at several time intervals after exposure over a period of 2 years. The dosimetric index is 2 to 4 times higher for the dose to the bone marrow than the results based on MIRD calculations, which are derived from individuals with normal thyroid function and normal metabolic activity. This study shows that chromosomal anomalies induced by radiation persist over long periods of time (2 years) and that a retrospective biological dosimetry can be established in patients exposed to ionizing radiations. Blood samples taken at 3 and 6 months and 1 and 2 years after administration of 131I demonstrated more reciprocal translocations than those taken at 4 days and the presence of the dicentrics without the 'accompagnateur' fragment. Stem cells produce new lymphocytes to make-up for the loss after 131I treatment. Direct estimation of the dose using our dosimetric index will provide a more accurate quantification of the risk incurred by exposure to 131I which until now, has been based exclusively on approximate statistical calculations of cumulative 131I doses. (authors)

  4. Biological dosimetry by the radiation effects on the skin

    International Nuclear Information System (INIS)

    In cases of partial body over-exposure, the dose estimation with personal monitors or with reconstruction of exposed conditions is often impossible without considerable error. Clinical signs of irradiated skin, such as epilation or moist desquamation have been used as the indicators of doses in the radiological accidents, because each sign has the threshold dose. As hair growth is known to be sensitive to radiation, the dose-effect relationship of the delay of hair regrowth and the reduction in hair length of mice after irradiation were examined to investigate if they can be used as biological dosimeters. Hairs on the dorsal skin of 290 ICR mice (8 weeks old) were shaved and irradiated with a Sr-90/Y-90 β-ray source in the early anagen and the midanagen stages of the hair cycle. Skin doses were from 0.5 to 10 Gy. The time of hair regrowth and the hair length were examined with the scaling loupe. Dose-effect relationship of the delay of hair regrowth and reduction in hair length were both clearly dose dependent, fitting the L-Q or L function depending on the stage. Dose estimation functions were derived from the dose-effect relationship curves. The histological observations suggested that hair growth retardation caused by irradiation in midanagen might be due to the cell death and the depression of mitosis in the hair matrix cells. This dose estimation method was applied to the case who was over-exposed to X-ray on his hand and fingers. The findings showed that hair regrowth delay was a sensitive biological dosimeter in the case of partial body over-exposure, which could be applied as early as a few days after over-exposure. The method was simple and non-invasive to the exposed patient. (author)

  5. Definition study of the project Dosimetry Brachytherapy

    International Nuclear Information System (INIS)

    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. Chromosomal analysis and application of biological dosimetry in two cases of apparent over exposure

    International Nuclear Information System (INIS)

    The gamma radiation calibration curve of 60 Co is used which was generated in the ININ Laboratory of Biology to calculate the exposure dose of two workers whose dosemeters marked values above of the limit allowed. The analysis indicates that in a first case, the aberrations frequency corresponded to the basal value, therefore there is not over exposure. The aberrations frequency of the second case is lightly above to the basal value and therefore the probability favors to what the physical dosimetry indicates. (Author)

  7. Bibliographical database of radiation biological dosimetry and risk assessment: Part 1, through June 1988

    Energy Technology Data Exchange (ETDEWEB)

    Straume, T.; Ricker, Y.; Thut, M.

    1988-08-29

    This database was constructed to support research in radiation biological dosimetry and risk assessment. Relevant publications were identified through detailed searches of national and international electronic databases and through our personal knowledge of the subject. Publications were numbered and key worded, and referenced in an electronic data-retrieval system that permits quick access through computerized searches on publication number, authors, key words, title, year, and journal name. Photocopies of all publications contained in the database are maintained in a file that is numerically arranged by citation number. This report of the database is provided as a useful reference and overview. It should be emphasized that the database will grow as new citations are added to it. With that in mind, we arranged this report in order of ascending citation number so that follow-up reports will simply extend this document. The database cite 1212 publications. Publications are from 119 different scientific journals, 27 of these journals are cited at least 5 times. It also contains reference to 42 books and published symposia, and 129 reports. Information relevant to radiation biological dosimetry and risk assessment is widely distributed among the scientific literature, although a few journals clearly dominate. The four journals publishing the largest number of relevant papers are Health Physics, Mutation Research, Radiation Research, and International Journal of Radiation Biology. Publications in Health Physics make up almost 10% of the current database.

  8. Bibliographical database of radiation biological dosimetry and risk assessment: Part 1, through June 1988

    International Nuclear Information System (INIS)

    This database was constructed to support research in radiation biological dosimetry and risk assessment. Relevant publications were identified through detailed searches of national and international electronic databases and through our personal knowledge of the subject. Publications were numbered and key worded, and referenced in an electronic data-retrieval system that permits quick access through computerized searches on publication number, authors, key words, title, year, and journal name. Photocopies of all publications contained in the database are maintained in a file that is numerically arranged by citation number. This report of the database is provided as a useful reference and overview. It should be emphasized that the database will grow as new citations are added to it. With that in mind, we arranged this report in order of ascending citation number so that follow-up reports will simply extend this document. The database cite 1212 publications. Publications are from 119 different scientific journals, 27 of these journals are cited at least 5 times. It also contains reference to 42 books and published symposia, and 129 reports. Information relevant to radiation biological dosimetry and risk assessment is widely distributed among the scientific literature, although a few journals clearly dominate. The four journals publishing the largest number of relevant papers are Health Physics, Mutation Research, Radiation Research, and International Journal of Radiation Biology. Publications in Health Physics make up almost 10% of the current database

  9. Cytogenetic effects of low ionising radiation doses and biological dosimetry

    OpenAIRE

    Gricienė, Birutė

    2010-01-01

    The intensive use of ionising radiation (IR) sources and development of IR technology is related to increased exposure and adverse health risk to workers and public. The unstable chromosome aberration analysis in the group of nuclear energy workers (N=84) has shown that doses below annual dose limit (50 mSv) can induce chromosome aberrations in human peripheral blood lymphocytes. Significantly higher frequencies of the total chromosome aberrations were determened in the study group when compa...

  10. Emergency preparedness exercise for biological dosimetry - BIOPEX (2008)

    International Nuclear Information System (INIS)

    As a continuation to the NKS-funded BIODOS project, the BIOPEX project has aimed at testing and validation of the newly established dose calibration curve for PCC rings, a specific chromosome aberration for use in biodosimetry in large casualty emergency preparedness. The testing of the PCC ring technique was performed by direct comparison to the conventional dicentric assay, both conducted with a triage approach that gives a crude dose estimate through analysis of a relatively small number of cells. Altogether 62 blood samples were analysed, each irradiated with an individual dose using γ-rays, and representing casualties in a simulated radiation accident resulting in a broad spectrum of whole body and partial body doses, ranging from zero dose up to a lethal whole body dose of 13 Gy. The results indicated that both triage assays were capable of discerning non-exposed cases and that in the uniform irradiations, the dose estimates based on data from both assays were fairly consistent with the given dose. However, differences were observed depending on the dose level. At doses about 5 Gy and below, dicentric scoring resulted in more accurate whole-body dose estimates than PCC rings. At very high doses, PCC rings appeared to give more accurate dose estimates than dicentrics. The discrepancies are mainly caused by shortcomings in the respective dose calibration curves. In non-uniform irradiations, the PCC ring assay was slightly better in the approximation of the partial body dose than dicentrics, but neither assay enabled accurate estimation of either dose or fraction of cells irradiated. The irradiated fraction of cells for the casualties in this scenario was apparently too small (10-40%) to be distinguished with the triage approach applied in the current study. With respect to the technical aspects, scoring of the PCC rings is easier and therefore somewhat faster but may be more sensitive to quality aspects. In conclusion, the study demonstrated that the PCC ring

  11. Emergency preparedness exercise for biological dosimetry - BIOPEX (2008)

    Energy Technology Data Exchange (ETDEWEB)

    Lindholm, C.; Paile, W. (Radiation and Nuclear Safety Authority (STUK) (Finland)); Stricklin, D. (Swedish Defence Research Agency (FOI) (Sweden)); Jaworska, A. (Norwegian Radiation Protection Authority (NRPA) (Norway))

    2009-03-15

    As a continuation to the NKS-funded BIODOS project, the BIOPEX project has aimed at testing and validation of the newly established dose calibration curve for PCC rings, a specific chromosome aberration for use in biodosimetry in large casualty emergency preparedness. The testing of the PCC ring technique was performed by direct comparison to the conventional dicentric assay, both conducted with a triage approach that gives a crude dose estimate through analysis of a relatively small number of cells. Altogether 62 blood samples were analysed, each irradiated with an individual dose using gamma-rays, and representing casualties in a simulated radiation accident resulting in a broad spectrum of whole body and partial body doses, ranging from zero dose up to a lethal whole body dose of 13 Gy. The results indicated that both triage assays were capable of discerning non-exposed cases and that in the uniform irradiations, the dose estimates based on data from both assays were fairly consistent with the given dose. However, differences were observed depending on the dose level. At doses about 5 Gy and below, dicentric scoring resulted in more accurate whole-body dose estimates than PCC rings. At very high doses, PCC rings appeared to give more accurate dose estimates than dicentrics. The discrepancies are mainly caused by shortcomings in the respective dose calibration curves. In non-uniform irradiations, the PCC ring assay was slightly better in the approximation of the partial body dose than dicentrics, but neither assay enabled accurate estimation of either dose or fraction of cells irradiated. The irradiated fraction of cells for the casualties in this scenario was apparently too small (10-40%) to be distinguished with the triage approach applied in the current study. With respect to the technical aspects, scoring of the PCC rings is easier and therefore somewhat faster but may be more sensitive to quality aspects. In conclusion, the study demonstrated that the PCC

  12. Study and validation of dosimetry in no-reference condition

    International Nuclear Information System (INIS)

    With the technological equipment used in radiotherapy became possible use of some radiation fields named 'small fields' in some special forms of radiotherapy. Thus, the dosimetry of radiation fields also had to be revised, as with these new sizes of fields, there is no reference condition such as that expressed in dosimetry protocols and guidelines. This work represents a complete study of small fields and its dosimetry, showing the behavior of the detectors in this new condition of dosimetry through a comparison between the detectors used and data already published. Moreover, the experimental data can be validated by comparison with data published by others authors. In the characterization of the same diamond detector has been considered appropriate in all parameters measured with small fields. The analysis of the beam quality factor (Q) the experimental results obtained in this study showed differences in percentages of 1.8%, 4.0% and 4.9% for chamber-type CC01, CC13 and stereotactic diode respectively. In evaluating PDP and TMR was possible to observe the difficulty in measurements with small fields and the comparison of different detectors, the biggest difference for PDP was 2.6% and 2.7% for TMR. (author)

  13. Extension of the biological effective dose to the MIRD schema and possible implications in radionuclide therapy dosimetry

    International Nuclear Information System (INIS)

    In dosimetry-based treatment planning protocols, patients with rapid clearance of the radiopharmaceutical require a larger amount of initial activity than those with slow clearance to match the absorbed dose to the critical organ. As a result, the dose-rate to the critical organ is higher in patients with rapid clearance and may cause unexpected toxicity compared to patients with slow clearance. In order to account for the biological impact of different dose-rates, radiobiological modeling is beginning to be applied to the analysis of radionuclide therapy patient data. To date, the formalism used for these analyses is based on kinetics derived from activity in a single organ, the target. This does not include the influence of other source organs to the dose and dose-rate to the target organ. As a result, only self-dose irradiation in the target organ contributes to the dose-rate. In this work, the biological effective dose (BED) formalism has been extended to include the effect of multiple source organ contributions to the net dose-rate in a target organ. The generalized BED derivation has been based on the Medical Internal Radionuclide Dose Committee (MIRD) schema assuming multiple source organs following exponential effective clearance of the radionuclide. A BED-based approach to determine the largest safe dose to critical organs has also been developed. The extended BED formalism is applied to red marrow dosimetry, as well as kidney dosimetry considering the cortex and the medulla separately, since both those organs are commonly dose limiting in radionuclide therapy. The analysis shows that because the red marrow is an early responding tissue (high α/β), it is less susceptible to unexpected toxicity arising from rapid clearance of high levels of administered activity in the marrow or in the remainder of the body. In kidney dosimetry, the study demonstrates a complex interplay between clearance of activity in the cortex and the medulla, as well as the initial

  14. Light scattering by irradiated cells as a method of biological dosimetry

    International Nuclear Information System (INIS)

    Light scattering (LS) parameters between 350-500 nm wavelength have been studied for 2 groups of cells: 1) blood (BL) and thymus (TL) lymphocytes of rats and mice, and 2) Ehrlich ascite tumor (EAT) cells. LS measurements of freshly prepared cell suspensions have been made 24 hrs after x-ray irradiation of rodents (250 Kev, HVL = 2 mm Cu) at doses of 50-900 cGy. A steep (30% per Gy) linear (50-800 cGy for TL and 50-400 cGy for BL) dose-dependence was obtained for the increase in 900-angle LS intensity. Increase in absorption (low-angle LS) was also linear (50-800 cGy for TL and BL) but less steep (9% per Gy). Irradiated cells were the same size as unirradiated. Changes in LS for TL and BL appear to follow the appearance of additional vacuoles which may become new internal smaller-size centers of LS. This suggestion is supported by direct observations of cells with dark-field microscopy. For EAT cells, both 900 and low angle LS had the same slope. This slope (4% per Gy) is much shallower than that for BL and TL, and quantitatively coincides with enlargement of area of EAT cells, which could explain LS changes. The difference in LS behavior of the two cellular groups reflects a difference in their early response to irradiation: interphase death for TL and BL, vs division delay for EAT cells. The above data suggest the fast and simple method of biological dosimetry

  15. Dosimetry study on A p-n junction semiconductor detector

    International Nuclear Information System (INIS)

    A p-n junction semiconductor may be used as a radiation detector. Such a study is reported here. Its dosimetry specificities, include dose, dose rate, precision, stability, depth dose distribution and directional response, were studied in a 60Co field. It is shown that the detector performs well. It exhibited a precision of ±0.05% (std dev.) and a stability of ±0.16% (std dev.), respectively. (author)

  16. Assessment of internal dose from incorporated plutonium-239 by means of biological dosimetry

    International Nuclear Information System (INIS)

    Intra- and inter-chromosomal aberration frequency in Mayak P.A. nuclear workers was studied by mFISH and mBAND techniques. Intra-chromosomal aberrations in lymphocytes from the peripheral blood were found to be a bio marker of densely-ionizing radiation (alpha-particles) in workers exposed to radiation many years ago. A dependence of the frequency of intra-chromosomal aberrations in plutonium workers on absorbed dose to the red bone marrow from internal exposure to incorporated plutonium-239 was found. A preliminary 'bio dosimetry system' was developed. Its capability to estimate internal doses from incorporated plutonium-239 in plutonium production workers based on the frequency of intra-chromosomal aberrations detected in these workers was tested. Estimates of internal doses from incorporated plutonium - 239 obtained using the preliminary 'bio dosimetry system' were compared with doses calculated by a model based on measurements of plutonium excretion in urine ('Mayak Doses-2000'). Estimates of internal doses from incorporated plutonium-239 obtained using both independent techniques demonstrated a highly significant correlation (correlation coefficient, R2 = 74%). At the current research phase, the developed 'bio dosimetry system' is to be adjusted, which will allow to estimate plutonium-239 body burden with an uncertainty less than 30%. (authors)

  17. In-situ fluorescence hybridization applied to biological dosimetry: contribution of automation to the counting of radio-induced chromosome aberrations

    International Nuclear Information System (INIS)

    The frequency of chromosome aberrations on peripheral blood lymphocytes is a dose indicator in the case of ionizing radiations over-exposure. Stable chromosome aberrations (translocations, insertions) are visualized after labelling of some chromosomes using the fluorescence in-situ hybridization (FISH). The study of the use of the FISH technique in biological dosimetry is done with dose-effect curves. It seems that a bias is introduced during the observation of chromosome aberrations involving only 3 pairs of chromosomes. In order to avoid this bias, it would be useful to test the feasibility of using the multi-FISH technique in biological dosimetry. Moreover, this type of chromosome aberration changes with the type of irradiation. It is thus important to define the aberrations to be considered when the FISH technique is used. In order to reduce the time of image analysis, the CYTOGEN system, developed by IMSTAR company (Paris, France) has been adapted to the needs of biological dosimetry. This system allows to localize automatically the metaphases on the slide, which reduces the observation time by 2 or 4. An automatic detection protocol for chromosome aberrations has been implemented. It comprises the image capture, the contours detection and the classification of some chromosome aberrations. The different steps of this protocol have been tested in order to check that no bias is introduced by the automation. However, because radio-induced aberrations are rare events, it seems that a totally automatic system is not foreseeable. A semi-automatic analysis is more suitable. The use of the Slit-Scan technology (Laboratory of applied physics, Heidelberg, Germany) in biological dosimetry has been studied too. This technique allows to analyze rapidly a huge number of chromosomes. A good correlation has been observed between the dicentric frequency measured automatically and by manual counting. The system is under development and should be adapted to the detection of

  18. Bibliographical database of radiation biological dosimetry and risk assessment: Part 2

    International Nuclear Information System (INIS)

    This is part 11 of a database constructed to support research in radiation biological dosimetry and risk assessment. Relevant publications were identified through detailed searches of national and international electronic databases and through our personal knowledge of the subject. Publications were numbered and key worded, and referenced in an electronic data-retrieval system that permits quick access through computerized searches on authors, key words, title, year, journal name, or publication number. Photocopies of the publications contained in the database are maintained in a file that is numerically arranged by our publication acquisition numbers. This volume contains 1048 additional entries, which are listed in alphabetical order by author. The computer software used for the database is a simple but sophisticated relational database program that permits quick information access, high flexibility, and the creation of customized reports. This program is inexpensive and is commercially available for the Macintosh and the IBM PC. Although the database entries were made using a Macintosh computer, we have the capability to convert the files into the IBM PC version. As of this date, the database cites 2260 publications. Citations in the database are from 200 different scientific journals. There are also references to 80 books and published symposia, and 158 reports. Information relevant to radiation biological dosimetry and risk assessment is widely distributed within the scientific literature, although a few journals clearly predominate. The journals publishing the largest number of relevant papers are Health Physics, with a total of 242 citations in the database, and Mutation Research, with 185 citations. Other journals with over 100 citations in the database, are Radiation Research, with 136, and International Journal of Radiation Biology, with 132

  19. Biological dosimetry of patients with differenced carcinoma of thyroid treated with Iodine-131

    International Nuclear Information System (INIS)

    The administration of I-131 to patient with Differentiated Thyroid Carcinoma (CaDiT) it is used inside the therapeutic outline as later step to the thyroidectomy. However, the good activity to give is of difficult determination due to factors such as, the variability in the capacity of tumoral reception of the I-131, distribution of the pharmaceutical, physiologic status, other associate pathologies, grade of advance of the illness, and previous treatments. Additionally, the activity to administer is dependent of the dose of tolerance in the healthy tissues; superior dose to 2 Gy in bone marrow, its could drive to myelotoxicity. At the moment, the form more extended of administration it is the empiric prescription that considers clinical parameters and of laboratory for their determination. Presently work, the protocol of applied treatment incorporates the evaluation for internal dosimetry and biological dosimetry to estimate absorbed dose in bone marrow. The biological estimate of the dose of these patients is based on the quantification of chromosomal aberrations whose frequency is referred to a curve-dose response in which the lymphocytes is irradiated in vitro with I-131, allowing to determine the in vivo dose to the patient's circulating lymphocytes. The objective of the present work is to determine the applicability of different cytogenetic essays in the estimate of the absorbed dose to the whole body or specific organs. Three patients were evaluated with CaDiT. Their treatment protocol consisted on a tracer administration of radioactive iodine of 74 - 111 MBq (2 - 3 mCi) and a therapy 7,4 - 11,1 GBq (200 - 300 mCi). Previous to the tracer administration and 8 days post-therapeutic administration took samples of veined blood that were evaluated by biological dosimetry by means of the application of the techniques: conventional cytogenetic Micronucleus and FISH (Hybridization in situ by Fluorescence). Starting from the frequencies of observed chromosomal

  20. Study of a personal passive multielement dosimeter for neutron dosimetry

    International Nuclear Information System (INIS)

    Personal neutron dosimetry is presently carried out with unsatisfying methods, viz. the use of nuclear emulsions ''blind'' for energy below 1.5 MeV, or the operation of albedo detectors that must be calibrated at the various working places since their responses vary largely as a function of neutron energies. A progress report is presented on the DINEM project studies. The DINEM (personal multielement neutron dosimeter) is made of an albedo dosimeter ''PGP-DIN'' detecting neutrons with energies below 7 keV and a solid track detector detecting energies above 100 keV. The latest improvements on the use of CN 85 as a solid track detector announce that the difficult problem of personal dosimetry should be solved soon

  1. Chromosome painting and prematurely condensed chromosomes (PCC) - new methods of biological dosimetry

    International Nuclear Information System (INIS)

    Classic methods of biological dosimetry - micronucleus and dicentric assay pose several problems. In the case of micronucleus there is a wide range of spontaneous frequencies and smoking and age are powerfull contributing factors. In the case of dicentrics - low mitotic index in some individuals especially in the elderly or accidentally exposed to high radiation doses. So, there are 2 quite new molecular techniques which at least in part solve these problems: chromosome painting and PCC. Chromosome painting by employing chromosome-specific DNA probes allow easy identification and quantification of translocations. recently, it was shown that calyculin A or okadaic acid, inhibitors of 1 and 2A protein phosphatases, induce PCC in peripheral blood cells. This is an easy biodosimetric method with a high PCC index and independent of the ability of cells to divide e.g. after high (20 Gy) doses when the mitotic index is extremely low. (author)

  2. Calibration curves for biological dosimetry; Curvas de calibracion para dosimetria biologica

    Energy Technology Data Exchange (ETDEWEB)

    Guerrero C, C.; Brena V, M. [ININ, A.P. 18-1027, 11801 Mexico D.F. (Mexico)]. E-mail cgc@nuclear.inin.mx

    2004-07-01

    The generated information by the investigations in different laboratories of the world, included the ININ, in which settles down that certain class of chromosomal leisure it increases in function of the dose and radiation type, has given by result the obtaining of calibrated curves that are applied in the well-known technique as biological dosimetry. In this work is presented a summary of the work made in the laboratory that includes the calibrated curves for gamma radiation of {sup 60} Cobalt and X rays of 250 k Vp, examples of presumed exposure to ionizing radiation, resolved by means of aberration analysis and the corresponding dose estimate through the equations of the respective curves and finally a comparison among the dose calculations in those people affected by the accident of Ciudad Juarez, carried out by the group of Oak Ridge, USA and those obtained in this laboratory. (Author)

  3. Assessment of occupational exposure and individual radiosensitivity in people exposed to radiation using methods of physical and biological dosimetry

    International Nuclear Information System (INIS)

    This paper examined people professionally in contact with sources of ionizing radiation.The incidence of chromosomal aberrations, the radionuclide content in the urine of the radiochemical method and calculation of internal doses based on the results of direct measurement of the concentration of incorporated radionuclides 137Cs and 241Am using human radiation spectrometer (HRS). According to the results of physical and biological dosimetry identified individual cumulative doses and the ratio defined cohort surveyed by radiosensitivity Key words: chromosomal aberrations, physical methods of dosimetry, radiation sensitivity, ionizing radiation, biodosimetry

  4. Patient dosimetry study of a paediatric CT examination

    International Nuclear Information System (INIS)

    Dosimetry studies are of increasing interest in diagnostic high-dose applications such as computed tomography especially for examinations of children. A routine CT scan protocol for paediatric head and neck imaging was investigated at a new multi-detector CT scanner using LiF:Mg,Cu,P thermoluminescence dosemeters (TLDs) and a 0.125 cm3 thimble ionization chamber. Calibrations of the detectors in terms of absorbed dose to water were carried out at the Dosimetry Laboratory Seibersdorf in standard radiation fields. The dosimetry method was validated in the spiral CT X-ray field by comparing TLD and ionization chamber measurement results in cylindrical PMMA phantoms. Absorbed dose results were within stated uncertainties. An anthropomorphic phantom representing a child of about 5 years was loaded with TLD chips at various organ and tissue positions in the head and neck region as well as at some critical organ locations. Organ dose values were calculated from TLD based average absorbed dose with about 5% total uncertainty, e.g. 22 mGy (eyes), 21 mGy (thyroid), 19 mGy (brain), 3.4 mGy (thymus), and 0.03 mGy (testes). For comparison purposes an effective dose of 1.9 mSv was estimated for the investigated paediatric CT examination based on ICRP-103 age-independent tissue-weighting factors.

  5. Hybrid 3D pregnant woman and fetus modeling from medical imaging for dosimetry studies

    International Nuclear Information System (INIS)

    Numerical simulations studying the interactions between radiations and biological tissues require the use of three-dimensional models of the human anatomy at various ages and in various positions. Several detailed and flexible models exist for adults and children and have been extensively used for dosimetry. On the other hand, progress of simulation studies focusing on pregnant women and the fetus have been limited by the fact that only a small number of models exist with rather coarse anatomical details and a poor representation of the anatomical variability of the fetus shape and its position over the entire gestation. In this paper, we propose a new computational framework to generate 3D hybrid models of pregnant women, composed of fetus shapes segmented from medical images and a generic maternal body envelope representing a synthetic woman scaled to the dimension of the uterus. The computational framework includes the following tasks: image segmentation, contour regularization, mesh-based surface reconstruction, and model integration. A series of models was created to represent pregnant women at different gestational stages and with the fetus in different positions, all including detailed tissues of the fetus and the utero-fetal unit, which play an important role in dosimetry. These models were anatomically validated by clinical obstetricians and radiologists who verified the accuracy and representativeness of the anatomical details, and the positioning of the fetus inside the maternal body. The computational framework enables the creation of detailed, realistic, and representative fetus models from medical images, directly exploitable for dosimetry simulations. (orig.)

  6. Biological dosimetry of atomic bomb survivors exposed within 500 meters from the hypocenter and the health consequences.

    Science.gov (United States)

    Kamada, N

    1999-12-01

    Seventy-eight atomic bomb survivors were examined for biological dosimetry using chromosome abnormality. They had been exposed within 500 meters from the hypocenter in heavily shielded conditions and were found from NHK-RIRBM joint study carried out from 1966 to 1971. Estimation of the exposure doses for these survivors was made under the following steps; 1) calculation by DS86 system (physically estimated doses) in survivors who had been exposed within 1,500 meters and had precise records of exposure conditions. RBE for the neutron was defined as 10. 2) setting of exposure dose-chromosome aberration curve, and 3) observation of chromosome aberrations in the proximally exposed survivors, for whom biological doses were estimated. Estimation of the exposure doses were possible from the aberration rate of chromosome in the peripheral lymphocytes, even 25-40 years after the exposure. Of the 78 survivors, 96% were estimated to have exposed more than one Sv. Detection of transforming gene(s) of N and K RAS genes in DNAs from non-leukemic survivors was carried out as one of the biological investigations for these heavily exposed survivors. All four survivors examined showed N or K RAS gene mutation. Three of the four healthy survivors had cancer or leukemia 7-10 years after the examination. Further continuous follow-up study of these heavily exposed people will give us more information on the late effects of A-bomb radiation, which may arise in the future. PMID:10805004

  7. Biological dosimetry of atomic bomb survivors exposed within 500 meters from the hypocenter and the health consequences

    International Nuclear Information System (INIS)

    Seventy eight atomic bomb survivors were examined for biological dosimetry using chromosome abnormality. They had been exposed within 500 meters from the hypocenter in heavily shielded conditions and were found from NHK-RIRBM joint study carried out from 1966 to 1971. Estimation of the exposure doses for these survivors was made under the following steps: calculation by DS86 system (physically estimated doses) in survivors who had been exposed within 1,500 meters and had precise records of exposure conditions. RBE for the neutron was defined as 10; setting of exposure dose-chromosome aberration curve; and observation of chromosome aberrations in the proximally exposed survivors, for whom biological doses were estimated. Estimation of the exposure doses were possible from the aberration rate of chromosome in the peripheral lymphocytes, even 25-40 years after the exposure. Of the 78 survivors, 96% were estimated to have exposed more than one Sv. Detection of transforming gene(s) of N and K RAS genes in DNAs from non-leukemic survivors was carried out as one of the biological investigations for these heavily exposed survivors. All four survivors examined showed N or K RAS gene mutation. Three of the four healthy survivors had cancer or leukemia 7-10 years after the examination. Further continuous follow-up study of these heavily exposed people will give us more information on the late effects of A-bomb radiation, which may arise in the future. (author)

  8. Biological dosimetry intercomparison exercise: an evaluation of Triage and routine mode results by robust methods

    International Nuclear Information System (INIS)

    Well-defined protocols and quality management standards are indispensable for biological dosimetry laboratories. Participation in periodic proficiency testing by interlaboratory comparisons is also required. This harmonization is essential if a cooperative network is used to respond to a mass casualty event. Here we present an international intercomparison based on dicentric chromosome analysis for dose assessment performed in the framework of the IAEA Regional Latin American RLA/9/054 Project. The exercise involved 14 laboratories, 8 from Latin America and 6 from Europe. The performance of each laboratory and the reproducibility of the exercise were evaluated using robust methods described in ISO standards. The study was based on the analysis of slides from samples irradiated with 0.75 (DI) and 2.5 Gy (DII). Laboratories were required to score the frequency of dicentrics and convert them to estimated doses, using their own dose-effect curves, after the analysis of 50 or 100 cells (triage mode) and after conventional scoring of 500 cells or 100 dicentrics. In the conventional scoring, at both doses, all reported frequencies were considered as satisfactory, and two reported doses were considered as questionable. The analysis of the data dispersion among the dicentric frequencies and among doses indicated a better reproducibility for estimated doses (15.6% for DI and 8.8% for DII) than for frequencies (24.4% for DI and 11.4% for DII), expressed by the coefficient of variation. In the two triage modes, although robust analysis classified some reported frequencies or doses as unsatisfactory or questionable, all estimated doses were in agreement with the accepted error of ±0.5 Gy. However, at the DI dose and for 50 scored cells, 5 out of the 14 reported confidence intervals that included zero dose and could be interpreted as false negatives. This improved with 100 cells, where only one confidence interval included zero dose. At the DII dose, all estimations fell within

  9. Analysis of MIR-18 results for physical and biological dosimetry: radiation shielding effectiveness in LEO

    International Nuclear Information System (INIS)

    We compare models of radiation transport and biological response to physical and biological dosimetry results from astronauts on the Mir space station. Transport models are shown to be in good agreement with physical measurements and indicate that the ratio of equivalent dose from the Galactic Cosmic Rays (GCR) to protons is about 3/2:1 and that this ratio will increase for exposures to internal organs. Two biological response models are used to compare to the Mir biodosimetry for chromosome aberration in lymphocyte cells; a track-structure model and the linear-quadratic model with linear energy transfer (LET) dependent weighting coefficients. These models are fit to in vitro data for aberration formation in human lymphocytes by photons and charged particles. Both models are found to be in reasonable agreement with data for aberrations in lymphocytes of Mir crew members: however there are differences between the use of LET dependent weighting factors and track structure models for assigning radiation quality factors. The major difference in the models is the increased effectiveness predicted by the track model for low charge and energy ions with LET near 10 keV/μm. The results of our calculations indicate that aluminum shielding, although providing important mitigation of the effects of trapped radiation, provides no protective effect from the galactic cosmic rays (GCR) in low-earth orbit (LEO) using either equivalent dose or the number of chromosome aberrations as a measure until about 100 g/cm2 of material is used

  10. Biological dosimetry in radiological protection: dose response curves elaboration for 60Co and 137Cs

    International Nuclear Information System (INIS)

    Ionizing radiation sources for pacific uses are being extensively utilized by modern society and the applications of these sources have raised the probability of the occurrence of accidents. The accidental exposition to radiation creates a necessity of the development of methods to evaluate dose quantity. This data could be obtained by the measurement of damage caused by radiation in the exposed person. The radiation dose can be estimated in exposed persons through physical methods (physical dosimetry) but the biological methods can't be dispensed, and among them, the cytogenetic one that makes use of chromosome aberrations (dicentric and centric ring) formed in peripheral blood lymphocytes (PBL) exposed to ionizing radiation. This method correlates the frequency of radioinduced aberrations with the estimated absorbed dose, as in vitro as in vivo, which is called cytogenetic dosimetry. By the introduction of improved new techniques in culture, in the interpretation of aberrations in the different analysers of slides and by the adoption of different statistical programs to analyse the data, significant differences are observed among laboratories in dose-response curves (calibration curves). The estimation of absorbed dose utilizing other laboratory calibration curves may introduce some uncertainties, so the International Atomic Energy Agency (IAEA) advises that each laboratory elaborates your own dose-response curve for cytogenetic dosimetry. The results were obtained from peripheral blood lymphocytes of the healthy and no-smoking donors exposed to 60Co and 137Cs radiation, with dose rate of 5 cGy.min.-1. Six points of dose were determined 20,50,100,200,300,400 cGy and the control not irradiated. The analysed aberrations were of chromosomic type, dicentric and centric ring. The dose response curve for dicentrics were obtained by frequencies weighted in liner-quadratic mathematic model and the equation resulted were for 60Co: Y = (3 46 +- 2.14)10-4 cGy-1 + (3.45 +- 0

  11. Spectroscopic studies of irradiated glasses: Application in nuclear dosimetry

    International Nuclear Information System (INIS)

    The present work aims to study the effects of ionizing radiation on silicate glasses in order to develop a new dosimetry system simple, precise, stable and inexpensive. Indeed, changes in mechanical properties, optical and paramagnetic glasses when subjected to ionizing radiation. The prediction of long-term behavior, physical aging under irradiation, the glass is paramount. many studies have brought many ways to avoid obscuring glass windows used in nuclear reactors or hot cells and optical devices. Recently, much work has concentrated on the application of the color induced by irradiation for developing a recyclable glass in the glass industry is of great interest economically and environmentally.

  12. Biological dosimetry: the potential use of radiation-induced apoptosis in human T-lymphocytes

    International Nuclear Information System (INIS)

    An assay for biological dosimetry based on the induction of apoptosis in human T-lymphocytes is described. Radiation-induced apoptosis was assessed by flow cytometric identification of cells displaying apoptosis-associated DNA condensation. CD4 and CD8 T-lymphocytes were analysed. They were recognized on the basis of their cell-surface antigens. Four parameters were measured for both cell types: cell size, granularity, antigen immunofluorescence and DNA content. Apoptosis was quantified as the fraction of CD4-, or CD8-positive cells with a characteristic reduction of cell size and DNA content. At doses below 1 Gy, levels of radiation-induced apoptosis increased for up to 5 days after irradiation. Optimal dose discrimination was observed 4 days after irradiation, at which time the dose-response curves were linear, with a slope of 8% ± 0.5% per 0.1 Gy. In controlled, dose-response experiments the lowest dose level at which the radiation-induced apoptosis frequency was still significantly above control was 0.05 Gy. After 5 days post-irradiation incubation, intra- and interdonor variations were measured and found to be similar; thus, apoptotic levels depend more on the dose than on the donor. The results demonstrate the potential of this assay as a biological dosimeter. (orig.)

  13. Alanine-ESR in vivo dosimetry: a feasibility study and possible applications

    International Nuclear Information System (INIS)

    A new alanine-ESR dosimeter has been developed at AERIAL in order to study its potential use in radiotherapy. Alanine-ESR results are compared with ion chamber for depth-dose measurements. A good concordance has been found between provisional dosimetry and absorbed dose during high dose rate and intra operative treatments. The results of the experiments indicate that alanine-ESR dosimetry is suited to check dose optimisation routines and seems to be a promising in vivo dosimetry technique. (Author)

  14. Dosimetry, instrumentation and exposure chambers for dc magnetic field studies

    Energy Technology Data Exchange (ETDEWEB)

    Tenforde, T.S.

    1979-03-01

    The principal objective of this report is to describe in detail an exposure chamber that was developed at the Lawrence Berkeley Laboratory for automated, noninvasive studies of rodent physiology during exposure to high DC magnetic fields. A second objective is to discuss some of the unique instrumentation problems that must be overcome in order to record bioelectric signals from laboratory animals in the presence of a magnetic field. Finally, a description will be given of the various dosimetry techniques that can be employed for quantitation of magnetic field strength.

  15. Dosimetry, instrumentation and exposure chambers for dc magnetic field studies

    International Nuclear Information System (INIS)

    The principal objective of this report is to describe in detail an exposure chamber that was developed at the Lawrence Berkeley Laboratory for automated, noninvasive studies of rodent physiology during exposure to high DC magnetic fields. A second objective is to discuss some of the unique instrumentation problems that must be overcome in order to record bioelectric signals from laboratory animals in the presence of a magnetic field. Finally, a description will be given of the various dosimetry techniques that can be employed for quantitation of magnetic field strength

  16. Solid State and Chemical Radiation Dosimetry in Medicine and Biology. Proceedings of a Symposium

    International Nuclear Information System (INIS)

    Proceedings of a Symposium organized by the IAEA and held in Vienna, 3-7 October 1966. The meeting was attended by 104 participants from 21 countries and three international organizations. Contents: Solid state dosimetry (17 papers); Chemical dosimetry (10 papers); Invited lectures (2 papers); General aspects and other methods of dosimetry (6 papers); Panel discussion on research and development needed in dosimetry. Each paper is in its original language (32 English, 2 French and 1 Spanish) and is preceded by an abstract in English and one in the original language, if this is not English. Discussions are in English. (author)

  17. Radiation dosimetry for epidemiology lung cancer study

    International Nuclear Information System (INIS)

    Lung doses have been calculated for 999 workers whose primary exposure was to airborne uranium during the period 1943 to 1947. Internal dose calculations were needed because the major exposure potential was to airborne uranium and because no external monitoring data exists. The lung dose estimates process was divided into two phases: estimation of the uranium intake and calculation of the internal dose. The intake information required included the number of hours worked and the concentration, chemical and physical forms of uranium. These factors were determined through researching historical documents including plant process descriptions, personnel records, operations records, monitoring records, etc. Additional information was also gained through interviews of former plant workers. Job titles and department codes were used to relate uranium exposure conditions to a given individual. Lung doses were estimated using internal dose models developed by Oak Ridge National Laboratory. This system takes into account both particle size and solubility class. Results show that some workers may have received doses as high as 74 rads or 740 rems if a quality factor of 10 is used. The results of this study have been used in a lung cancer case control study to be reported at this conference

  18. Comparative study of Si diodes for gamma radiation dosimetry

    International Nuclear Information System (INIS)

    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 60Co 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)

  19. [Long-term follow-up cytogenetic survey and biological dosimetry in persons evacuated from 30-km Chernobyl NPP zone].

    Science.gov (United States)

    Maznik, N A

    2004-01-01

    The paper presents the results of the follow-up cytogenetic survey and biological dosimetry carried out in inhabitants of Pripiat' town and nearby villages, who were departured from the Chernobyl NPP 30-km exclusive zone during first days after the Chernobyl catastrophe. The unstable chromosome aberration level in inhabitants were significantly increased above control in terms up to 1 year after evacuation and declined gardually during next 14 years. In early period the cytogenetic damage frequency in evacuees showed no dependence on gender. The chromosome type aberration level appeared to be lower in young persons comparing with adults. The dicentrics plus centric rings yield had a positive correlation with duration of staying at Chernobyl zone. The average doses of protracted exposure were calculated from the dicentrics and centric rings yields; the dose estimations appeared to be 1.4 times higher in persons evacuated 3-11 days after the accident than that of in persons with shorter departure time. Uing the Bayesian analysis the probabilistic distribution of biological doses was constructed for the studied evacuees group. This distribution was characterized by a mean dose of 360 mGy, the modal doses of 200-450 mGy and 80% of probability density within the dose range 0-1000 mGy, that seems to be sufficient for considering the increased risk of late somatic radiation effects for this cohort. PMID:15571047

  20. The use of apoptosis in human lymphocytes peripheral as alternative methods in biological dosimetry of radiation effects from cobalt-60

    International Nuclear Information System (INIS)

    Gamma rays affect cells in dose-response manner, resulting in cell death, as in cancer radiotherapy. The ionizing radiation acts by transferring energy, mainly by free radicals from water radiolysis that result in nucleic acid damage and other effects in lipids and proteins, The level of exposure is indirectly estimated by physical dosimetry, but the biological dosimetry can measure the direct radiation effect, mainly in post-dividing cells by classical cytogenetic approach. Recently, it was reported that irradiated cells develop an induced programmed death or apoptosis. With a biological dosimetric technique, we measured apoptotic cell fraction in 60Co in vitro irradiated blood cells from voluntary healthy donors. The agarose gel electrophoresis showed a low sensitivity, because cell DNA presented the characteristic pattern only when the cells were exposed to 100 c Gy or more. Using a terminal DNA labeling technique we observed that the apoptotic cell fraction proportionally increases with irradiation. Similar sensitivity was observed when compared to classical cytogenetics (3 c Gy minimum detection level). These techniques are easier to perform, do not need cell culture and all cells, including interphase ones, can be analyzed, providing a good tool in biological dosimetry. (author)

  1. Review of translocations detected by fish for retrospective biological dosimetry applications

    International Nuclear Information System (INIS)

    Several European laboratories have combined their research efforts to arrive at a consensus view on using fluorescence in situ hybridisation (FISH) for retrospective dosimetry. The aim of this review is to report these views and to highlight some areas where further work is needed. Translocations in the stable cells should be measured only in the cells that contain the full complement of the painted material. Two-way and one-way translocations should be combined with equal weight. The control level of translocations has a strong dependence on age, which has now been measured and the system has been calibrated. In conclusion, the technique works and a lifetime dose to the bone marrow from low-linear energy transfer radiation of 0.5 Gy above normal background levels can be measured for any individual. The main application is considered to provide an independent verification of lifetime doses to individuals who might form a part of an epidemiological study. (authors)

  2. Neutron dosimetry - A review

    International Nuclear Information System (INIS)

    This review summarizes information on the following subjects: (1) physical processes of importance in neutron dosimetry; (2) biological effects of neutrons; (3) neutron sources; and (4) instruments and methods used in neutron dosimetry. Also, possible improvements in dosimetry instrumentation are outlined and discussed. (author)

  3. Problems in dosimetry study in the Hiroshima atomic bomb

    International Nuclear Information System (INIS)

    Dosimetry study 1986 (DS86) was constructed by the effort of US and Japanese groups and used afterward at Radiation Effects Research Foundation. The DS86 has been used to estimate radiation risks for cancer induction of radiation based on the epidemiological study of atomic bomb survivors. However, discrepancy between neutron-induced data and calculation based on DS86 has been observed. The discrepancy was found in the evaluated neutron dose in Hiroshima. To find the reason of the discrepancy, experimental study were continued for more than 10 years among Japanese and US groups. However there was no answer. In this review, the activities of the Japanese groups are explained and a model to explain the discrepancy is shown. The new US and Japan joint study is beginning and effort to evaluate atomic bomb dose for survivors are still continuing. (author)

  4. Dosimetry implications of BSH biodistribution study at OSU

    International Nuclear Information System (INIS)

    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)

  5. Nuclear accident dosimetry studies at Los Alamos National Laboratory

    International Nuclear Information System (INIS)

    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

  6. Thermoluminescence Dosimetry Studies at the Philippine Atomic Research Center

    International Nuclear Information System (INIS)

    Thermoluminescence dosimetry studies have been initiated at the Philippine Atomic Research Center of the Philippine Atomic Energy Commission. A recalibration of the equipment indicates a divergence from supplied calibration curves, especially with regard to the dark current. Operating currents and heating temperatures also show a statistical uncertainty of approximately 7%. Gamma-dose calibrations were undertaken using a 60Co gamma garden previously mapped with an R-meter and chemical dosimeters. Neutron dose calibrations have been attempted using the Philippine research reactor. Some isodose curves in a dry gamma room from a 20 000 Ci 60Co source inside the PRR-I reactor pool were presented. The values of parameters α, β, Np, N0 were obtained for both unannealed LiF and annealed LiF. The values fitted the model of thermoluminescence versus dose suggested by Cameron et al. Using the same model the values of these parameters were obtained for CaSO4 : Mn. (author)

  7. The FISH chromosome painting technique in Biological Dosimetry : Evolution and applicability; La Tecnica de Pintado Cromosomico mediante FISH en Dosimetria Biologica: Evolucion y Aplicabilidad

    Energy Technology Data Exchange (ETDEWEB)

    Oteo, M.; Real, A.

    2005-07-01

    The capacity of ionising radiation to induce chromosomal aberrations has been used during decades to assess doses in persons accidentally exposed, giving rise to the discipline Biological Dosimetry. the Biological Dosimetry is a complement to the physical methods of dosimetry and in the situations where those are not available represent the only way to asses the doses received. During decades biological dosimetry has used the dicentric score to determine doses, since a good correlation between in vitro and in vivo irradiation results exists and the background yields are low. However, dicentrics yields decrease with time after irradiation. The translocations and insertions represent stable aberrations what means that they do not decrease in further cell divisions. The development at the end of the 80s of the FISH technique (Fluorescence In Situ Hybridization), represented a great step for the applicability of translocations score for biological dosimetry. In this paper, a review of the FISH chromosome painting technique is presented, addressing the facts that have needed to be solve before its routine use in retrospective dosimetry, as well as the aspects that will need further research in the near future. (Author) 54 refs.

  8. 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

  9. Evaluation of the Biological Shields of the Secondary Standard Dosimetry Laboratory of Ghana Using MCNP5

    Directory of Open Access Journals (Sweden)

    P. Deatanyah

    2012-03-01

    Full Text Available The primary objective with radiation sources and facilities is the protection of both radiation workers and the general public. The biological shields of the Secondary Standard Dosimetry Laboratory of the Radiation Protection Institute (RPI Ghana had been evaluated for a collimated isotropic cesium-137 source for calibration purpose using MCNP5 code. The dose rate at supervised areas ranged from 0.57 to 8.35 :Sv/h and 0.26 to 10.22 :Sv/h at control areas when the source was panoramic. When the source was collimated, the dose rate ranged from 0.05 to 0.30 :Sv/h at supervised areas and 0.23 to 8.88 :Sv/h at control areas for 22.2 GBq of the cesium-137 source. The scatter contribution from the surfaces of the walls and roofs were also accounted for. The scatter radiation in the room decreased to 400 :Sv/h when the source was first collimated and to 3.5 :Sv/h when the source was further collimated. These results agreed quite well with experimental measurement. To effectively protect the staff, a narrow beam of 1.2 cm diameter which was defined at 1.0 m by the total surface of the ISO slab phantom was recommended to reduce the dose rate to less than 1.5 :Sv/h outside the calibration bunker even when the current activity is doubled. It was concluded that the 4.7 cm diameter of the existing narrow beam should be decreased to 1.2 cm by further collimation of the beam.

  10. Application of the alkaline comet assay to rat alveolar macrophages after homogeneous or heterogeneous irradiation: a biological dosimetry method

    International Nuclear Information System (INIS)

    The alkaline comet assay, also called alkaline single cell gel electrophoresis, is a simple technique to assess single strand breaks, double strand breaks and alkali sites. It is based on the ability of broken DNA to migrate more easily in an electric field than normal DNA. This method is well adapted for the assessment of the ionising radiations effects on single cells. The aim of this study is to develop a biological dosimetry method to estimate the dose delivered to the respiratory tract by an homogeneous (60Co) or an heterogeneous (radon) irradiation. The animal model chosen is the rat because it has been validated for the study of the carcinogenic role of radon in man. Alveolar macrophages have been selected for there homogeneous distribution in the deep lung. After an in vivo thoracic 60Co gamma irradiation or a radon inhalation, it can be considered that these cells received a dose which is representative from the whole dose received by the lung. The comet assay is performed on alveolar macrophages recovered by broncho-alveolar lavage, and comet moment is measured with an epi-fluorescence microscope coupled to an image acquisition and analysis computing system. The results show the residence of a dose - comet moment relationship after in vivo 60Co gamma and radon irradiations. The technique used enabled us to show differences between homogeneous and heterogeneous irradiations in term of comet moments distributions. Although these results are promising, this technique has to be improved for the detection of biological effects induced by low doses of irradiation in order to detect potential effects of indoor radon exposure. (authors)

  11. The biological response of plucked human hair to low-dose radiation: a measure of individual radiosensitivity and a technique for biological dosimetry

    International Nuclear Information System (INIS)

    It is often assumed that the effects of radiation are linear with dose and that high dose effects can be extrapolated to low dose levels. However, there are a variety of mechanisms which can alter the response at low doses. The most important of these relate to induced sensitivity or induced repair mechanisms. It is therefore important that this area is studied in more depth by looking at the molecular effects and damage to cells at low doses. It is well known that there are certain rare genetic syndromes which predispose individuals to cancer, e.g. ataxia telangiectasia. It is also probable that there is a large range of sensitivity in the natural variation of individuals to the risk of radiation-induced cancer. It is proposed that radiosensitivity is studied using stimulated lymphocytes from whole blood and the technique extended to look at the effects in cell cultures established from human hair. Radiation treatment of cell cultures established from plucked human hair has been previously advocated as a non-invasive technique for non-uniform biological dosimetry and it is proposed that these techniques are adapted to the use of hair to estimate individual radiosensitivity. The aim is to establish and optimize these techniques for culturing keratinocytes from plucked human hair follicles with a view to study biological markers for the subsequent assessment of radiosensitivity. Preliminary results are promising and suggest that the technique for culturing keratinocytes from hair presents a feasible approach. Results from this primary cell culture technique and results from the comparison of the micronuclei data obtained from the cell cultures and stimulated lymphocytes will be presented. (author)

  12. Thermoluminescent Dosimetry: A Preliminary Study for microCT Applications

    International Nuclear Information System (INIS)

    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

  13. Contribution of new cytogenetic techniques in the estimations of old irradiations in retrospective biological dosimetry

    International Nuclear Information System (INIS)

    The objective of this study was to answer three questions: if the translocations are steady: the results have shown that the translocations even if they are not obligatory steady can be used in retrospective dosimetry. Furthermore, it appeared important to consider the complex translocations in view of their relative stability and complementary information they bring ( quality of radiation, received dose). The second question is what contribution of the M-F.I.S.H. in the translocations analysis in comparison with the F.I.S.H.-3: we have shown that the M-F.I.S.H. would allow to raise the whole of doubt due to a partial genome observation. that has for effect to increase the precision of the analysis and that what ever be the received dose. The third question is if there are differences between the chromosomal aberrations generated by x radiation of 50 keV and by gamma radiation from cobalt-60: yes, the low energy photons generate more translocations than the photons coming from cobalt-60. But they generate less dicentrics. this difference comes from the way the energy is deposited that leads to a more important formation of complex and multiple translocations with the low energy photons. this could constitute a problem in the use of low energy photons in radiotherapy. it would seem that the simple translocations rate is not influenced by the photons energy. (N.C.)

  14. Dose intercomparison studies for standardization of high-dose dosimetry in Viet Nam

    International Nuclear Information System (INIS)

    The Irradiation Center of the Vietnam Atomic Energy Commission (IC-VAEC) is planning to establish a traceability system for high-dose dosimetry and to provide high-dose standards as a secondary standard dosimetry laboratory (SSDL) level in Vietnam. For countries which do not have a standard dosimetry laboratory, the participation in the International Dose Assurance Service (IDAS) operated by the International Atomic Energy Agency (IAEA) is the most common means to verify own dosimetry performance with a certain uncertainty. This is, however, only one-direction dose intercomparison with evaluation by IAEA including unknown parameter at participant laboratories. The SSDL level laboratory should have traceability as well as compatibility, ability to evaluate uncertainties of its own dosimetry performance by itself In the present paper, we reviewed our dosimetry performance through two-way dose intercomparison studies and self-evaluation of uncertainty in our dosimetry procedure. The performance of silver dichromate dosimeter as reference transfer dosimeter in IC-VAEC was studied through two-way blind dose intercomparison experiments between the IC-VAEC and JAERI. As another channel of dose intercomparison with IAEA, alanine dosimeters issued by IDAS were simultaneously irradiated with the IC-VAEC dichromate dosimeters at IC-VAEC and analyzed by IAEA. Dose intercomparison between IC-VAEC and JAERI results into a good agreement (better than ±2.5%), and IDAS results also show similar agreement within ±3.0%. The uncertainty was self-estimated on the basis of the JAERI alanine dosimetry, and a preliminary value of about 1.86% at a 68% confidence level is established. The results from these intercomparisons and our estimation of the uncertainty are consistent. We hope that our experience is valuable to other countries which do not have dosimetry standard laboratories and/or are planning to establish them. (author)

  15. Biological dosimetry of ionizing radiation by chromosomal aberration analysis; Dosimetria biologica de las radiaciones ionizantes mediante el analisis de aberraciones cromosomicas

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez-Castano, S.; Silva, A.; Navlet, J.

    1990-07-01

    Biological dosimetry consists of estimating absorbed doses for people exposed to radiation by mean biological methods. Several indicators used are based in haematological, biochemical, and cytogenetic data, although nowadays without doubt, the cytogenetic method is considered to be the most reliable. In this case, the study ol chromosomal aberrations, normally dicentric chromosomes, in peripheral lymphocytes can be related to absorbed dose through an experimental calibration curve. An experimental dose-response curve, using dicentric chromosomes analysis, X-rays at 300 kVp, 114 rad/min and temperature 37 degree celsius has been produced. Experimental data is fitted to model Y ={alpha} + {beta}{sub 1}D + {beta}{sub 2}D 2 , where Y is the number of dicentrics per cell and D the dose. The curve is compared with those produced elsewhere. (Author) 14 refs.

  16. On the biological basis for competing macroscopic dose descriptors for kilovoltage dosimetry: cellular dosimetry for brachytherapy and diagnostic radiology

    Science.gov (United States)

    Thomson, R. M.; Carlsson Tedgren, Å.; Williamson, J. F.

    2013-02-01

    The purpose of this work is to investigate how alternative macroscopic dose descriptors track absorbed dose to biologically relevant subcellular targets via Monte Carlo (MC) analysis of cellular models for a variety of cancerous and normal soft tissues for kilovoltage radiation. The relative mass distributions of water, light inorganic elements, and protein components of nuclear and cytoplasm compartments for various tissues are determined from a literature review. These data are used to develop representative cell models to demonstrate the range of mass elemental compositions of these subcellular structures encountered in the literature from which radiological quantities (energy absorption and attenuation coefficients; stopping powers) are computed. Using representative models of cell clusters, doses to subcellular targets are computed using MC simulation for photon sources of energies between 20 and 370 keV and are compared to bulk medium dose descriptors. It is found that cells contain significant and varying mass fractions of protein and inorganic elements, leading to variations in mass energy absorption coefficients for cytoplasm and nuclear media as large as 10% compared to water for sub-50 keV photons. Doses to subcellular structures vary by as much as 23% compared to doses to the corresponding average bulk medium or to small water cavities embedded in the bulk medium. Relationships between cellular target doses and doses to the bulk medium or to a small water cavity embedded in the bulk medium are sensitive to source energy and cell morphology, particularly for lower energy sources, e.g., low energy brachytherapy (water or the corresponding average bulk tissue. For kilovoltage photon sources, neither dose to bulk medium nor dose to water quantitatively tracks energy imparted to biologically relevant subcellular targets for the range of cellular morphologies and tissues considered.

  17. 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

  18. Radiochromic films for dental CT dosimetry: a feasibility study.

    Science.gov (United States)

    Rampado, O; Bianchi, S D; Peruzzo Cornetto, A; Rossetti, V; Ropolo, R

    2014-02-01

    Dental CT dose evaluations are commonly performed using thermoluminescent dosimeters (TLD) inside anthropomorphic phantoms. Radiochromic films with good sensitivity in the X-ray diagnostic field have recently been developed and are commercially available as GAFCHROMIC XR-QA. There are potential advantages in the use of radiochromic films such as a more comprehensive dosimetry thanks to the adjustable size of the film samples. The purpose of this study was to investigate the feasibility of using radiochromic films for dental CT dose evaluations. Film samples were cut with a width of 5mm and a length of 25 mm (strips), the same size as the Alderson Rando anthropomorphic phantom holes used in this study. Dental CT dose measurements were performed using simultaneously both TLD and radiochromic strips in the same phantom sites. Two equipment types were considered for dental CT examinations: a 16 slice CT and a cone beam CT. Organ equivalent doses were then obtained averaging the measurements from the sites of the same organ and effective doses were calculated using ICRP 103 weighting factors. The entire procedure was repeated four times for each CT in order to compare also the repeatability of the two dosimeter types. A linear correlation was found between the absorbed dose evaluated with radiochromic films and with TLD, with slopes of 0.930 and 0.944 (correlation r>0.99). The maximum difference between the two dosimeter's measurements was 25%, whereas the average difference was 7%. The measurement repeatability was comparable for the two dosimeters at cumulative doses above 15 mGy (estimated uncertainty at 1 sigma level of about 5%), whereas below this threshold radiochromic films show a greater dispersion of data, of about 10% at 1 sigma level. We obtained, using respectively Gafchromic and TLD measurements, effective dose values of 107 μSv and 117 μSv (i.e. difference of 8.6%) for the cone beam CT and of 523 μSv and 562 μSv (i.e. difference of 7%) for the

  19. 1982 US-CEC neutron personnel dosimetry intercomparison study

    International Nuclear Information System (INIS)

    A neutron personnel dosimetry intercomparison study was conducted during April 19-23, 1982, as a joint effort between the United States and the Commission of European Communities. Dosimeters from 48 participating agencies were mounted on cylindrical phantoms and exposed to a range of low-level dose equivalents (0.48-13.91 mSv neutron and 0.02-1.32 mSv gamma) in nine different radiation fields. Exposure conditions considered in this study included four mixed-field spectra produced using the Health Physics Research Reactor, four monoenergetic neutron fields generated by accelerators, and one 15-cm D2O-moderated californium source spectrum. In general, neutron results reported by the participating agencies were consistent with expected dosimeter performance based on energy response characteristics of the detection systems. Albedo dosimeters, which were the most popular neutron monitoring systems used in this study, provided the best overall accuracy for all exposure conditions. Film, Cr-39 recoil track, and Th-232 fission track systems generally underestimated dose equivalents relative to reference values. Associated gamma measurements showed that TLD monitors produced more accurate results than film dosimeters although both systems overestimated gamma dose equivalents in mixed radiation fields. 24 references, 10 figures, 19 tables

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

    International Nuclear Information System (INIS)

    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)

  1. 3D-personalized Monte Carlo dosimetry in 90Y-microspheres therapies of primary and secondary hepatic cancers: absorbed dose and biological effective dose considerations

    International Nuclear Information System (INIS)

    Full text of publication follows. Purpose: a 3D-Personalized Monte Carlo Dosimetry (PMCD) was developed for treatment planning in nuclear medicine. The method was applied to Selective Internal Radiation Therapy (SIRT) using 90Y-microspheres for unresectable hepatic cancers. Methods: The PMCD method was evaluated for 20 patients treated for hepatic metastases or hepatocellular carcinoma at the European Hospital Georges Pompidou (Paris). First, regions of interest were outlined on the patient CT images. Using the OEDIPE software, patient-specific voxel phantoms were created. 99mTc-MAA SPECT data were then used to generate 3D-matrices of cumulated activity. Absorbed doses and Biologically Effective Dose (BED) were calculated at the voxel scale using the MCNPX Monte Carlo transport code. Finally, OEDIPE was used to determine the maximum injectable activity (MIA) for tolerance criteria on organs at risk (OARs), i.e. the lungs and non tumoral liver (NTL). Tolerance criteria based on mean absorbed doses, mean BED, Dose-Volume Histograms (DVHs) or BED-Volume Histograms (BVHs) were considered. Those MIAs were compared to the Partition Model with tolerance criteria on mean absorbed doses, which is a conventional method applied in clinical practice. Results: compared to Partition Model recommendations, performing dosimetry using the PMCD method enables to increase the activity prescription while ensuring OARs' radiation protection. Moreover, tolerance criteria based on DVHs allow us to enhance treatment planning efficiency by taking advantage of the parallel characteristic of the liver and the lungs, whose functions are not impaired if the level of irradiation to a fraction of the organ is kept sufficiently low. Finally, multi-cycle treatments based on tolerance criteria on mean BED and BVHs, were considered to go further in the dose optimization, taking into account biological considerations such as cell repair or radiosensitivity. Conclusion: besides its feasibility

  2. Study on the development of a patient dosimetry gown for interventional cardiology procedures

    International Nuclear Information System (INIS)

    In recent years, dose justification and optimization have been attempted in percutaneous coronary intervention (PCI); however, deterministic effects have been reported. To prevent radiation skin injuries in PCI, it is necessary to measure the patient entrance skin dose (ESD), but an accurate dose measurement method has not yet been established. In this study, we developed a dosimetry gown that can measure the ESD during PCI using multiple radiophotoluminescence dosimeters (RPLDs). The RPLDs were placed into 84 pockets that were sewn into a dosimetry gown. Patients wear the original dosimetry gown during the procedures, after which we obtain accurate ESD measurements. We believe that this method using RPLDs and a newly-designed dosimetry gown provides accurate ESD measurements during PCI. We expect this system to become a standard method for measuring ESD during PCI. (author)

  3. Biological (DB) and internal dosimetry (DI) in patients with differentiated thyroid carcinoma (CaDT) treated with iodine 131

    International Nuclear Information System (INIS)

    The internal 131I radiotherapy in patients with CaDT is used within the therapeutic scheme as a step post-thyroidectomy. The success of therapy is to achieve a lethal dose in the tumor tissue without exceeding the dose of tolerance in healthy tissues (doses greater than 2 Gy in bone marrow could lead to myelotoxicity). In this work, the treatment protocol applied incorporates assessment by biological (DB) and internal dosimetry (DI) for estimating doses to the whole body and bone marrow to administer a therapeutic personalized for each patient. The estimate biological dose is based in the quantification of chromosomal aberrations, which is referred to a dose-response curve. Objectives: 1) To estimate the absorbed dose to the whole body and bone marrow due to the administration of 131I therapy in patients with CaDT, by applying three different cytogenetic tests: conventional cytogenetics, micronuclei (MN) and fluorescence in situ hybridization (FISH); 2) Assess the correlation of the results obtained by DB and DI for personalization of treatment. Materials and methods: We evaluated 24 patients with CaDiT by applying the cytogenetic tests mentioned and internal dosimetry (methodology Mird-Olinda). Internal dosimetry: We administered a tracer dose 74 to 111 MBq. Measurements were made of activity in whole body and blood. By adjusting the scheme was estimated MIRD dose in bone marrow and the maximum therapeutic activity to manage and secure. Through software Olinda was determined absorbed dose to the whole body for each patient. We considered patient-specific data (physical frame size, weight, hematocrit) to adjust the methodology in each particular case. It is assumed that the tracer activity administered has a kinetic in the body similar to the 131I to be administered in therapeutic amounts. Biology Dosimetry : We performed for each patient taking 2 sequential venous blood samples to estimate the dose due to therapeutic activity in review: the first shows, pre

  4. Retrospective dosimetry using unheated quartz: A feasibility study

    DEFF Research Database (Denmark)

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

    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...

  5. GEANT4 for breast dosimetry: parameters optimization study

    Science.gov (United States)

    Fedon, C.; Longo, F.; Mettivier, G.; Longo, R.

    2015-08-01

    Mean glandular dose (MGD) is the main dosimetric quantity in mammography. MGD evaluation is obtained by multiplying the entrance skin air kerma (ESAK) by normalized glandular dose (DgN) coefficients. While ESAK is an empirical quantity, DgN coefficients can only be estimated with Monte Carlo (MC) methods. Thus, a MC parameters benchmark is needed for effectively evaluating DgN coefficients. GEANT4 is a MC toolkit suitable for medical purposes that offers to the users several computational choices. In this work we investigate the GEANT4 performances testing the main PhysicsLists for medical applications. Four electromagnetic PhysicsLists were implemented: the linear attenuation coefficients were calculated for breast glandularity 0%, 50%, 100% in the energetic range 8-50 keV and DgN coefficients were evaluated. The results were compared with published data. Fit equations for the estimation of the G-factor parameter, introduced by the literature for converting the dose delivered in the heterogeneous medium to that in the glandular tissue, are proposed and the application of this parameter interaction-by-interaction or retrospectively is discussed. G4EmLivermorePhysicsList shows the best agreement for the linear attenuation coefficients both with theoretical values and published data. Moreover, excellent correlation factor ({{r}2}>0.99 ) is found for the DgN coefficients with the literature. The final goal of this study is to identify, for the first time, a benchmark of parameters that could be useful for future breast dosimetry studies with GEANT4.

  6. Radiation dosimetry.

    OpenAIRE

    Cameron, J.

    1991-01-01

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

  7. 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)

    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

  8. Biological effects of radiation and dosimetry in X-ray diagnostics of children

    International Nuclear Information System (INIS)

    The chest radiograms represent the basic radiological examinations of thorax. The basis for radiation protection especially in pediatrics is the exact determination of doses. The risk estimation of genome damages can be received in human peripheral blood lymphocytes using alkaline version of Comet Assay. The aim of this work was assessment and quantification of the level of DNA damage in peripheral blood lymphocytes of children during airways X-ray examinations of chest and to compare data to the dose of exposure. Doses were determined using thermoluminescence (TL) dosimetry and radiophotoluminescent (RPL) glass dosimetry system. Twenty children with pulmonary diseases, ages between 5 and 14 years were assessed. Dose measurements were conducted for poster-anterior (PA) projection on the forehead, thyroid gland, gonads, chest and back. We used a 150 kV Shimadzu CH-200 M X-ray unit. Peripheral blood samples were taken from children after and prior to X-ray exposure and were examined with the alkaline Comet Assay. Comet Assay is one of the standard techniques for assessing genome damage with variety applications in genotoxicity testing as well as fundamental research in DNA damage and repair. As a measure of DNA damage tail length was used, calculated from the centre of the head and presented in micrometers (μm). Mean value of group after irradiation was 14.04 ± 1.74 as opposed to mean value of group before irradiation that was 13.15 ± 1.33. Differences between mean tail lengths were statistically significant (P<0.05, ANOVA). In addition, correlation was found between doses in primary beam (measured on the back) and the ratio of tail length (DNA damage) before and after irradiation. Doses measured with TL and RPL dosimeters showed satisfactory agreement and both dosimetry methods are suitable for dosimetric measurements in X-ray diagnostics. (author)

  9. Transient impedance changes in venous endothelial monolayers as a biological radiation dosimetry response

    OpenAIRE

    Erik Fossum Young

    2012-01-01

    In March of 2011, a magnitude 9.0 earthquake and subsequent 14 m-high tsunami caused major damage to the Fukushima Daiichi nuclear power plant in Japan.  While cancer incidence in the radiation-exposed population is a logical concern, the complex effects of radiation on the heart and cardiovascular system are also of interest.  Immediate and early vascular radiation effects could be exploited as a dosimetry modality.  To test whether non-coronary vasculature exhibited transient perturbation i...

  10. A personal dosimetry intercomparison study in Asian and Pacific region

    International Nuclear Information System (INIS)

    Two personal dosimeter intercomparisons were conducted under International Atomic Energy Agency's RCA (Regional Cooperative Agreement) radiation protection project for Asian and Pacific region during 1990 - 1997. The first intercomparison program was carried out from 1990 to 1992. The main objective of that program was to obtain information on the technical status of basic radiation protection measurements in each participating member country and their ability to conduct monitoring for occupational protection. The dosimeters were irradiated free-in-air and the doses were expressed as exposure in R. The program was successfully completed and the results have been published. The second personal dosimeter intercomparison program was conducted from 1995 to 1997. A major objective of the second program was assess the ability of RCA member state personal dosimetry services to make measurements in terms of the operational quantity, personal dose equivalent, Hp(d), including suitable use of the associated calibration procedures. More than thirty dosimetry services from 16 RCA member countries participated in this program. The intercomparison was performed in two irradiation phases. Four calibration laboratories from three member countries provided X-ray and gamma ray irradiations for over a thousand dosimeters. The irradiations were conducted in 12 categories, defined by their photon energies and angles of incidence, using ISO water filled back-scatter phantom. All the results were expressed as the ratio of the dose value evaluated by each participant to the delivered dose. The deviations of these values from unity were used for analyzing the results. The performance of each dosimetry system was evaluated against draft recommendations of the International Atomic Energy Agency for personal dosimetry system accuracy. The results showed that the quality of individual monitoring in most of the RCA member countries was at an acceptable level with a few exceptions. They also

  11. Biological and clinical dosimetry. Progress report July 1, 1964-June 30, 1979

    International Nuclear Information System (INIS)

    The dosimetric studies at this laboratory were initiated with the primary goal of developing systems for the determination of absorbed dose in biological research and clinical applications. The primary method under study is the local absorbed dose calorimeter, a concept initiated and developed by J. S. Laughlin. In addition, secondary dosimetric systems such as ionization chambers, chemical dosimeters and thermoluminescent dosimeters (TLD) are being developed and applied to provide an absolute basis for the evaluation and comparison of experiments, treatments, and other procedures using radiation

  12. Study and characterization of dosimeter LiF:Mg,Cu,P for using in aeronautical dosimetry

    International Nuclear Information System (INIS)

    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

  13. Internal sources dosimetry

    International Nuclear Information System (INIS)

    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 .

  14. New tool for biological dosimetry: Reevaluation and automation of the gold standard method following telomere and centromere staining

    International Nuclear Information System (INIS)

    Graphical abstract: - Highlights: • We have applied telomere and centromere (TC) staining to the scoring of dicentrics. • TC staining renders the scoring of dicentrics more rapid and robust. • TC staining allows the scoring of not only dicentrics but all chromosomal anomalies. • TC staining has led to a reevaluation of the radiation dose–response curve. • TC staining allows automation of the scoring of chromosomal aberations. • Automated scoring of dicentrics after TC staining was as efficient as manual scoring. - Abstract: Purpose: The dicentric chromosome (dicentric) assay is the international gold-standard method for biological dosimetry and classification of genotoxic agents. The introduction of telomere and centromere (TC) staining offers the potential to render dicentric scoring more efficient and robust. In this study, we improved the detection of dicentrics and all unstable chromosomal aberrations (CA) leading to a significant reevaluation of the dose–effect curve and developed an automated approach following TC staining. Material and methods: Blood samples from 16 healthy donors were exposed to 137Cs at 8 doses from 0.1 to 6 Gy. CA were manually and automatically scored following uniform (Giemsa) or TC staining. The detection of centromeric regions and telomeric sequences using PNA probes allowed the detection of all unstable CA: dicentrics, centric and acentric rings, and all acentric fragments (with 2, 4 or no telomeres) leading to the precise quantification of estimated double strand breaks (DSB). Results: Manual scoring following TC staining revealed a significantly higher frequency of dicentrics (p < 10−3) (up to 30%) and estimated DSB (p < 10−4) compared to uniform staining due to improved detection of dicentrics with centromeres juxtaposed with other centromeres or telomeres. This improvement permitted the development of the software, TCScore, that detected 95% of manually scored dicentrics compared to 50% for the best currently

  15. Atomic bomb dosimetry systems for life span study in Hiroshima and Nagasaki

    International Nuclear Information System (INIS)

    The Life Span Study (LSS) of the atomic bomb survivors in Hiroshima and Nagasaki has provided invaluable qualitative data on the late effects of ionizing radiations to human beings. For the study, the best possible estimates of the atomic bomb radiations received by the organs or tissues of survivors were principally required. The first dose estimates for the survivors were designated as Tentative 1957 Doses (T57D). In 1965, a revised dosimetry system was constructed on the basis of experimental data from a field measurement with the Health Physics Research Reactor (HPRR) at Nevada and from the thermoluminescence measurements of ceramic material and the radioactivity measurements of iron materials in Japan. These dose estimates were designated as Tentative 1965 (T65D). The T65D system was used with a great deal of confidence for risk assessment throughout the 1970s. In 1980, however, two scientific groups in the United States challenged the validity of the T65D system. In the fall of 1981, a Working Group on Atomic Bomb Dosimetry Reassessment was organized both in the United States and in Japan. After four US-Japan Joint Workshops for Reassessment of Atomic Bomb Radiation Dosimetry, the new dosimetry system which is designated as Dosimetry System 1986 (DS86) was constructed. Recently, the Radiation Effects Research Foundation (RERF) has published the results of LSS which focussed on a comparison of the radiation-related risks of site-specific cancer mortality based on the DS86 and the T65D and deaths from cancer in the years 1950 to 1985. The International Commission on Radiological Protection (ICRP) has issued its basic recommendations as ICRP Publication 60 including the revised dose limits in occupational exposures. This paper reviews the dosimetry system of survivors for the LSS and discusses the physical basis for the DS86. (author)

  16. Field models and numerical dosimetry inside an extremely-low-frequency electromagnetic bioreactor: the theoretical link between the electromagnetically induced mechanical forces and the biological mechanisms of the cell tensegrity.

    Science.gov (United States)

    Mognaschi, Maria Evelina; Di Barba, Paolo; Magenes, Giovanni; Lenzi, Andrea; Naro, Fabio; Fassina, Lorenzo

    2014-01-01

    We have implemented field models and performed a detailed numerical dosimetry inside our extremely-low-frequency electromagnetic bioreactor which has been successfully used in in vitro Biotechnology and Tissue Engineering researches. The numerical dosimetry permitted to map the magnetic induction field (maximum module equal to about 3.3 mT) and to discuss its biological effects in terms of induced electric currents and induced mechanical forces (compression and traction). So, in the frame of the tensegrity-mechanotransduction theory of Ingber, the study of these electromagnetically induced mechanical forces could be, in our opinion, a powerful tool to understand some effects of the electromagnetic stimulation whose mechanisms remain still elusive. PMID:25202652

  17. Biological dosimetry of X-rays using in-Vitro micronucleus assay in human lymphocytes

    International Nuclear Information System (INIS)

    Micronuclei (Mn) are products of fragmented chromosomes which are recently being used as an alternative approach to the chromosome aberrations analysis for the estimation of biological absorbed dose in the case of occupationally exposed radiation workers including those working in industrial radiography, diagnostic radiology, nuclear medicine departments, as well as in nuclear installations. In the present work human blood samples were taken and after in- vitro irradiation with various doses of X-rays, in the dose range of 5-50 and 50-300 cgs were studied. Micronucleus test was performed using cytokinesis blocked cells. The best fit was obtained by linear quadratic model, Y=C +αD +βD2. Moreover we have observed X-ray induced micronucleus in lymphocytes from 7 exposed hospital X-ray workers. The micronucleus counts in these persons were 3-7 fold higher than those in control

  18. Perofrmance testing of personnel dosimetry services. Final report of a two-year pilot study, October 1977-September 1979

    International Nuclear Information System (INIS)

    A two-year pilot study was conducted of the Health Physics Society Standards Committee (HPSSC) Standard titled, Criteria for Testing Personnel Dosimetry Performance. The objectives of the pilot study were: to give processors an opportunity to correct any problems that are uncovered; to develop operational and administrative prodedures to be used later by a permanent testing laboratory; and to determine whether the proposed HPSSC Standard provides an adequate and practical test of dosimetry performance. Fifty-nine dosimetry processors volunteered to submit dosimeters for test irradiations according to the requirements of the HPSSC Standard. The feasibility of using the HPSSC Standard for a future mandatory testing program for personnel dosimetry processors is discussed. This report shows the results of the pilot study and contains recommendations for revisions in the Standard that will make a mandatory testing program useful to regulatory agencies, dosimetry processors, and radiation workers that use personnel dosimeters

  19. 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. PMID:22974332

  20. Preliminary study for dosimetry of toenail using Optically Stimulated Luminescence (OSL)

    Energy Technology Data Exchange (ETDEWEB)

    Nam, Hyun Il; Choi, Hoon; Park, Byeong Ryong; Lee, Byung Il [Radiation Health Research Institute, Seoul (Korea, Republic of)

    2012-10-15

    Optically Stimulated Luminescence(OSL) techniques similar to those used in dating have been adopted for retrospective dose assessment i.e. reconstruction of radiation doses received by the general population after nuclear accidents. Typically, radiation doses are determined using luminescence measurements carried out on quartz and feldspar samples extracted from bricks, tiles, pottery, or porcelain items collected in radiation contamination areas such as Hiroshima and Chernobyl (e.g. Godfrey Smith and Haskell, 1993; Haskell, 1993; Bailiff, 1995; B{phi}t ter Jensen, 1995; B{phi}t ter Jensen, 1996; B{phi}t ter Jensen et al. 1996). In the present study, OSL has been examined for its potential in emergency dosimetry using different materials as possible personal dosimeters. Radiation Health Research Institute has been conducting research on the physical, biological methods for the assessment of treatment and dose for radiation workers work accident. some other materials have been tested for possible use as personal emergency OSL dosimeters. materials examined included human nails (both from fingers and toes), we compare the OSL response of these materials with toenails on the existing tooth and nail for basic research and conduct research.

  1. Eighteenth nuclear accident dosimetry intercomparison study: August 10-14, 1981

    International Nuclear Information System (INIS)

    The Eighteenth Nuclear Accident Dosimetry Intercomparison Study was conducted August 10-14, 1981, 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 showed that about 56% of the reported neutron doses measured using foil activation, thermoluminescent, or sodium activation methods and about 53% of the gamma doses measured using thermoluminescent methods met nuclear accident dosimetry guidelines which suggest accuracies of +- 25% for neutron dose and +- 20% for gamma dose. The greatest difficulties in measuring accident doses occurred in radiation fields with large fractions of low energy neutrons and a high gamma component (> 40%). Results of this study indicate that continued accident dosimetry intercomparisons are necessary to test dosimetry systems and training programs are needed to improve the technical competence of evaluating personnel

  2. A study on the characteristics of enamel to electron spin resonance spectrum for retrospective dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Dae Seok; Lee, Kun Jai [Korea Advanced Institute of Science and Technology, Taejon (Korea, Republic of)

    2003-10-01

    Electron Spin Resonance (ESR) spectroscopy is one of the methods applicable to retrospective dosimetry. The retrospective dosimetry is a part of dose reconstruction for estimation of exposed dose occurred years before the estimation. A tooth can be separated as enamel, dentine and cementum. Among the three parts, enamel is known as to show the best sensitivity to the absorbed dose and is most widely used. Since the later 80s, ESR dosimetry with tooth enamel has been studied and applied for the retrospective dosimetry. There are some factors affecting the sensitivity of enamel to absorbed dose. One of the factors is a size of enamel. Grain size of the 1.0mm{approx}0.1mm range is commonly used and 0.6mm{approx}0.25mm is recommended in other study. But the sensitivity can be varied by the grain size. In this study, the granular effect of enamel to the sensitivity is examined for application to retrospective dosimetry. In the enamel separation, to minimize the physically induced ESR spectrum, only chemical separation method was used. Separated enamels were divided by their size. The sizes of each sample is 1.0mm{approx}0.71mm, 0.5mm{approx}0.3mm, and below 0.1mm, respectively. All enamel samples show ESR spectrum related to the absorbed dose and the ESR spectrum shows linearity to the absorbed dose. The sensitivities are similar for each sample. But the enamel of size below 0.1mm shows poor characteristics relative to other enamel size. So, it is not recommended to use enamel samples below 0.1mm.

  3. Preliminary Study on the Development of Extremity Dosimetry Program at Korean Nuclear Power Plants

    Energy Technology Data Exchange (ETDEWEB)

    Kong, Tae Young; Kim, Hee Geun [Korea Electric Power Research Institute, Daejeon (Korea, Republic of); Lee, Sang Gu; Jeong, Taek Min; Ah, Yong Min [Korea Hydro and Nuclear Power Co., Seoul (Korea, Republic of)

    2008-05-15

    The extremities are defined as the portions of the whole body from the upper elbow to the fingers and the knees to the toes including the knee. The extremity dosimetry system is the thermoluminescent dosimeter (TLD) used to assess dose equivalent resulting from external radiation to the extremities. In particular, these dosimeters were used in possible cases of high radiation exposure to extremities during radiation works to provide an estimate of shallow absorbed dose received when worn by an individual. From the mid 1990s, the standards to provide an estimate of whole body dose to radiation workers were established according to provisions of the atomic energy law and have been applied to Korean nuclear power plants (NPPs). However, there are no completed technical criteria to provide an estimate of extremity dose, so that the accuracy of dose assessment and the practical use of extremity dosimeter to Korean NPPs are relatively insufficient. Although several Korean NPPs are furnished with extremity dosimeters, they do not provide personnel extremity dosimetry service due to the insufficiency of standards for provision and dose calculation algorithm. In this study, to provide the technical background for the application of personnel extremity dosimetry service in Korean NPPs, the current status of technical standards and researches for extremity dosimetry was preliminarily investigated. In addition, this paper briefly described the extremity dose management at Korean NPPs.

  4. Preliminary Study on the Development of Extremity Dosimetry Program at Korean Nuclear Power Plants

    International Nuclear Information System (INIS)

    The extremities are defined as the portions of the whole body from the upper elbow to the fingers and the knees to the toes including the knee. The extremity dosimetry system is the thermoluminescent dosimeter (TLD) used to assess dose equivalent resulting from external radiation to the extremities. In particular, these dosimeters were used in possible cases of high radiation exposure to extremities during radiation works to provide an estimate of shallow absorbed dose received when worn by an individual. From the mid 1990s, the standards to provide an estimate of whole body dose to radiation workers were established according to provisions of the atomic energy law and have been applied to Korean nuclear power plants (NPPs). However, there are no completed technical criteria to provide an estimate of extremity dose, so that the accuracy of dose assessment and the practical use of extremity dosimeter to Korean NPPs are relatively insufficient. Although several Korean NPPs are furnished with extremity dosimeters, they do not provide personnel extremity dosimetry service due to the insufficiency of standards for provision and dose calculation algorithm. In this study, to provide the technical background for the application of personnel extremity dosimetry service in Korean NPPs, the current status of technical standards and researches for extremity dosimetry was preliminarily investigated. In addition, this paper briefly described the extremity dose management at Korean NPPs

  5. Activities of Project 'Cooperation and development with Latin America and Iberian in Biological Dosimetry of Iberian Group of Radiation Protection Societies

    International Nuclear Information System (INIS)

    In 1996 the GRIAPRA Group (Latin American and Iberian Group of Radiation Protection Societies) was established with the participation of Argentina, Brazil, Cuba, Mexico, Peru, Portugal and Spain. In 1998 began the biennial Collaborative Working Project 'Cooperation and Development with Latin America in Biological Dosimetry', partially supported by the Extremadura Government, Spain, initially involving five countries: Argentina, Cuba, Peru, Portugal and Spain. The general aim of the project is to create an Latin American and Iberian Biological Dosimetry Laboratories Coordinated Group in order to: give mutual cooperation and to other countries if required, in the case of radiological accident; contribute to enhance the technical capabilities of the participant laboratories; promote the installment of laboratories on this field in countries that does not have it yet through the training of human resources and providing the necessary equipment and, finally, perform jointly research activities in biological dosimetry. The activities designed in order to accomplish the project specific aims for the 1998-2000 period have been achieved. Description and results are presented. (author)

  6. The Utility of Lymphocyte Premature Chromosome Condensation Analysis for Biological Dosimetry Following Accidental Overexposure to Ionising Radiation

    International Nuclear Information System (INIS)

    Premature chromosome condensation (PCC) appears to have a possible utility for biological dosimetry purposes. The PCC technique may be adapted for cases of suspicion of overexposure where sampling is performed at least one day after an accident. For this purpose, human blood samples were exposed in vitro to 60Co (0.5 Gy.min-1) up to 4 Gy and the PCC technique was performed after 24 h, 48 h, and 72 h of DNA repair at 37 deg. C. Analysis of excess PCC fragments distribution showed an overdispersion and the dose-effect relationship was best characterised by linear regression. Radiation-induced damage was reduced to 32% between the first and the second day of repair and to 42% the following day. Statistical precision of the dose was found to be dependent on the irradiation dose and on the number of cells examined. The necessity to establish dose-response relationships after different periods of DNA repair is demonstrated, and the use of PCC excess fragments yield as a bioindicator should take this fact into account. (author)

  7. Concerted Uranium Research in Europe (CURE): toward a collaborative project integrating dosimetry, epidemiology and radiobiology to study the effects of occupational uranium exposure.

    Science.gov (United States)

    Laurent, Olivier; Gomolka, Maria; Haylock, Richard; Blanchardon, Eric; Giussani, Augusto; Atkinson, Will; Baatout, Sarah; Bingham, Derek; Cardis, Elisabeth; Hall, Janet; Tomasek, Ladislav; Ancelet, Sophie; Badie, Christophe; Bethel, Gary; Bertho, Jean-Marc; Bouet, Ségolène; Bull, Richard; Challeton-de Vathaire, Cécile; Cockerill, Rupert; Davesne, Estelle; Ebrahimian, Teni; Engels, Hilde; Gillies, Michael; Grellier, James; Grison, Stephane; Gueguen, Yann; Hornhardt, Sabine; Ibanez, Chrystelle; Kabacik, Sylwia; Kotik, Lukas; Kreuzer, Michaela; Lebacq, Anne Laure; Marsh, James; Nosske, Dietmar; O'Hagan, Jackie; Pernot, Eileen; Puncher, Matthew; Rage, Estelle; Riddell, Tony; Roy, Laurence; Samson, Eric; Souidi, Maamar; Turner, Michelle C; Zhivin, Sergey; Laurier, Dominique

    2016-06-01

    The potential health impacts of chronic exposures to uranium, as they occur in occupational settings, are not well characterized. Most epidemiological studies have been limited by small sample sizes, and a lack of harmonization of methods used to quantify radiation doses resulting from uranium exposure. Experimental studies have shown that uranium has biological effects, but their implications for human health are not clear. New studies that would combine the strengths of large, well-designed epidemiological datasets with those of state-of-the-art biological methods would help improve the characterization of the biological and health effects of occupational uranium exposure. The aim of the European Commission concerted action CURE (Concerted Uranium Research in Europe) was to develop protocols for such a future collaborative research project, in which dosimetry, epidemiology and biology would be integrated to better characterize the effects of occupational uranium exposure. These protocols were developed from existing European cohorts of workers exposed to uranium together with expertise in epidemiology, biology and dosimetry of CURE partner institutions. The preparatory work of CURE should allow a large scale collaborative project to be launched, in order to better characterize the effects of uranium exposure and more generally of alpha particles and low doses of ionizing radiation. PMID:27183135

  8. 2004 update of dosimetry for the Utah Thyroid Cohort Study.

    Science.gov (United States)

    Simon, Steven L; Anspaugh, Lynn R; Hoffman, F Owen; Scholl, Alan E; Stone, Mary B; Thomas, Brian A; Lyon, Joseph L

    2006-02-01

    In the 1980s, individual thyroid doses and uncertainties were estimated for members of a cohort of children identified in 1965 in Utah and Nevada who had potentially been exposed to fallout from the Nevada Test Site. That reconstruction represented the first comprehensive assessment of doses received by the cohort and was the first large effort to assess the uncertainty of dose on an individual person basis. The data on dose and thyroid disease prevalence during different periods were subsequently used in an analysis to determine risks of radiogenic thyroid disease. This cohort has received periodic medical follow-up to observe changes in disease frequency and to reassess the previously reported radiation-related risks, most recently after a Congressional mandate in 1998. In a recent effort to restore the databases and computer codes used to estimate doses in the 1980s, various deficiencies were found in the estimated doses due to improperly operating computer codes, corruption of secondary data files, and lack of quality control procedures. From 2001 through 2004, the dosimetry system was restored and corrected and all doses were recalculated. In addition, two parameter values were updated. While the mean of all doses has not changed significantly, many individual doses have changed by more than an order of magnitude. PMID:16435919

  9. Biological study in schizophrenia

    International Nuclear Information System (INIS)

    Schizophrenia is associated with enormous morbidity, mortality, personal disability, and social cost. Although considerable research on schizophrenia has been performed, the etiology of this disease has not been fully elucidated. In recent years, imaging and genetic technologies have been developed dramatically. Disturbances in glutamate and gamma-aminobutyric acid (GABA)ergic neurotransmission may underlie the pathophysiology of schizophrenia. We attempted an integrative review, of studies pertaining to recent advances of schizophrenia research with a focus on neuroimaging and genetic studies. Additionally, we present the preliminary findings of the clinical research in our outpatient unit, specialized for early intervention, at the University of Tokyo Hospital. (author)

  10. The impact of possible modifications to the DS86 dosimetry on neutron risk and relative biological effectiveness.

    Science.gov (United States)

    Hunter, Nezahat; Charles, Monty W

    2002-12-01

    The current DS86 dosimetry system for the Japanese bomb survivors indicates that neutron doses were so low that they prevent the direct derivation of any useful estimates of neutron risk. However, the large body of thermal neutron activation measurements carried out over many years in Hiroshima and Nagasaki appear to indicate that current DS86 neutron doses may have been significantly underestimated in Hiroshima. An earlier companion paper has provided an update of neutron activation measurements. While a large body of data appears to support a significant increase, there is ongoing debate and review regarding its validity. However, as yet, there are no detailed, peer-reviewed, published refutations of the neutron activation data which appear to support an increase in neutron doses. In this paper, we consider the impact of possible future revisions in the DS86 dosimetry on radiation risk estimates. We consider the extreme range of possibilities from maintaining the existing DS86 values, to changes in neutron doses in accord with the majority of existing neutron activation data. We have used the latest cancer incidence data and cancer mortality data for the A-bomb survivors, and neutron doses have been modified using a neutron revision factor (NRF) in line with the latest thermal neutron activation measurements in Hiroshima. In contrast to previous analyses, a nonlinear relationship between log(NRF) and slant range has been used which better represents the data beyond slant ranges of approximately 1 km. The impact on the evaluation of neutron relative biological effectiveness (RBE) and gamma radiation risk estimates has been assessed. While DS86 neutron doses are too low to allow any useful direct evaluation of neutron risk or neutron RBE, it becomes possible to derive more meaningful values if neutron doses are increased in Hiroshima in line with the broad range of thermal neutron activation measurements. The uncertainties are smallest for the cancer incidence data

  11. Four-dimensional dosimetry validation and study in lung radiotherapy using deformable image registration and Monte Carlo techniques

    International Nuclear Information System (INIS)

    Thoracic cancer treatment presents dosimetric difficulties due to respiratory motion and lung inhomogeneity. Monte Carlo and deformable image registration techniques have been proposed to be used in four-dimensional (4D) dose calculations to overcome the difficulties. This study validates the 4D Monte Carlo dosimetry with measurement, compares 4D dosimetry of different tumor sizes and tumor motion ranges, and demonstrates differences of dose-volume histograms (DVH) with the number of respiratory phases that are included in 4D dosimetry. BEAMnrc was used in dose calculations while an optical flow algorithm was used in deformable image registration and dose mapping. Calculated and measured doses of a moving phantom agreed within 3% at the center of the moving gross tumor volumes (GTV). 4D CT image sets of lung cancer cases were used in the analysis of 4D dosimetry. For a small tumor (12.5 cm3) with motion range of 1.5 cm, reduced tumor volume coverage was observed in the 4D dose with a beam margin of 1 cm. For large tumors and tumors with small motion range (around 1 cm), the 4D dosimetry did not differ appreciably from the static plans. The dose-volume histogram (DVH) analysis shows that the inclusion of only extreme respiratory phases in 4D dosimetry is a reasonable approximation of all-phase inclusion for lung cancer cases similar to the ones studied, which reduces the calculation in 4D dosimetry

  12. [Theoretical and experimental dosimetry in evaluation of biological effects of electromagnetic field for portable radio transmitters. Report 1. Flat phantoms].

    Science.gov (United States)

    Perov, S Iu; Bogacheva, E V

    2014-01-01

    Results of the theoretical (numerical) and experimental dosimetry approach for portable radio transmitters are considered. The simulation and measurement results are shown. A generic type of a portable radio transmitter operating in a very high frequency range was tested as an electromagnetic field source. The analysis of specific absorption rate distribution in the flat homogeneous phantom was carried out on the basis of a portable radio transmitter. The results have shown the admissible divergence between measurements and simulation. According to these results, the authors have come to the conclusion about using the complex dosimetry approach including experimental and numerical dosimetry. PMID:25764846

  13. Advances in biomedical dosimetry

    International Nuclear Information System (INIS)

    The symposium was organized in order to focus on the problems, developments and areas of further research in the life sciences. Forty-nine papers were presented dealing with instrumentation, techniques, experimental and theoretical studies. They included neutron sources and mixed-field dosimetry; developments (e.g. thermocurrent dosimetry) in dosimetry; physical aspects of radiation therapy, and treatment planning; international, national and regional radiation metrology programmes; diagnostic medical x-ray sources, imaging systems and patient doses; high-energy electron and γ-ray dosimetry; and doses determination for ingested or administered radionuclides

  14. Australasian brachytherapy audit: results of 'end-to-end' dosimetry pilot study

    International Nuclear Information System (INIS)

    We present the results of a pilot study to test the feasibility of a brachytherapy dosimetry audit. The feasibility study was conducted at seven sites from four Australian states in both public and private centres. A purpose-built cylindrical water phantom was imaged using the local imaging protocol and a treatment plan was generated to deliver 1Gy to the central (1 of 3) thermoluminescent dosimeter (TLD) from six dwell positions. All centres completed the audit, consisting of three consecutive irradiations, within a 2-h time period, with the exception of one centre that uses a pulsed dose rate brachytherapy unit. All TLD results were within 4.5% of the predicted value, with the exception of one subset where the dwell position step size was incorrectly applied. While the limited data collected in the study demonstrated considerable heterogeneity in clinical practice, the study proved a brachytherapy dosimetry audit to be feasible. Future studies should include verification of source strength using a Standard Dosimetry Laboratory calibrated chamber, a phantom that more closely mimics the clinical situation, a more comprehensive review of safety and quality assurance (QA) procedures including source dwell time and position accuracy, and a review of patient treatment QA procedures such as applicator position verification.

  15. X-ray imaging and the skin: Radiation biology, patient dosimetry and observed effects

    International Nuclear Information System (INIS)

    A wide variety of radiation-induced deterministic skin effects have been observed after X-ray guided interventions ranging from mild effects, such as transient erythema or temporary epilation, to severe effects, such as desquamation and necrosis. Radiation biologists have identified, in addition to absorbed dose to the skin, other factors that strongly influence the type and severity of a skin reaction, including exposure-related factors (dose rate, fractionation, the size of the exposed area and its site), biological factors (age, oxygen status, capillary density, hormonal status and genetic factors) and ethnic differences. A peak entrance skin dose of 2 Gy is an arbitrary, but pragmatic, threshold for radiation-induced skin effects after X-ray guided interventions. Transient skin injury originating in the epidermis is not expected in the average patient population at peak entrance skin doses up to 6 Gy. Serious skin effects are not likely to occur in clinical practice when optimised X-ray equipment is used in combination with good techniques for fluoroscopy and imaging. However, this might not be true for patients with biological factors that are associated with an increased sensitivity for radiation-induced skin reactions. (authors)

  16. Feasibility study on pinhole camera system for online dosimetry in boron neutron capture therapy

    International Nuclear Information System (INIS)

    The feasibility of a pinhole camera system for online dosimetry in boron neutron capture therapy (BNCT) was studied. A prototype system was designed and built. Prompt γ-rays from the 10B(n,α)7Li reaction from a phantom irradiated with neutrons were detected with the prototype system. An image was reconstructed from the experimental data. The reconstructed image showed a good separation of the two borated regions in the phantom. The counting rates and signal-to-noise ratio when using the system in actual BNCT applications are also discussed. - Author-Highlights: • The feasibility of a pinhole camera system for online dosimetry in BNCT was studied. • A prototype pinhole camera system for online dose imaging for BNCT was built. • Prompt γ-rays from a phantom irradiated with neutrons were detected. • The boron-10 reaction rate distribution was reconstructed from the experimental data

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

    OpenAIRE

    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...

  18. Cytogenetic biological dosimetry in radiological protection: chromosome aberration analysis in human lymphocyties

    International Nuclear Information System (INIS)

    The effects of ionizing radiation on chromosomes have been know for several decades and dose effect relationships are also fairly well established for several doses and dose rates. Apart from its biological significance, the interpretation of chromosome aberration frequency associated with human exposure to radiation plays an important role in dose assessment, particularly in cases where exposure is though to have occurred but no physical dose monitoring system was present. Based on the cytogenetic data obtained from seven cases of exposure to radiation the aberration frequency have been fitted to the quadratic function Y= αD + βD2 as the dose response curves from literature. The dose equivalent estimate by frequency of chromosomic aberration found here was compared with 60Co and 192Ir already published curves obtained at almost similar dose rate together with some hematological data. (author)

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

    Energy Technology Data Exchange (ETDEWEB)

    Nogueira, Luciana B.; Campos, Tarcisio P.R., E-mail: lucibn19@yahoo.com.br [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil)

    2013-07-01

    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)

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

    International Nuclear Information System (INIS)

    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)

  1. Nuclear accident dosimetry: Los Alamos measurements at the seventeenth nuclear accident dosimetry intercomparison study at the Oak Ridge National Lab., DOSAR Facility, August 1980

    International Nuclear Information System (INIS)

    Teams from various US and foreign organizations participated in the Seventeenth Nuclear Accident Dosimetry Study held at the Oak Ridge National Laboratory's (ORNL) Dosimetry Applications Research (DOSAR) facility August 11 to 15, 1980. Criticality dosimeters were simultaneously exposed to pulses of mixed neutron and gamma radiation from the Health Physics Research Reactor (HPRR). This report summarizes the experimental work conducted by the Los Alamos team. In-air and phantom measurements were conducted by the Los Alamos team using area and personnel dosimeters. Combined blood sodium and sulfur fluence measurements of absorbed dose were also made. In addition, indium foils placed on phantoms were evaluated for the purpose of screening personnel for radiation exposure. All measurements were conducted for unshielded, 5-cm steel and 20-cm concrete shielding configurations. All participant dosimeters were exposed at 3 m from the center of the HPRR core

  2. External audit of photon beams by mailed film dosimetry: feasibility study

    International Nuclear Information System (INIS)

    A feasibility study for mailed film dosimetry has been performed. The global reproducibility of the method is better than 2%. It is shown that the normalized sensitometric curve does not depend on photon beam quality in the range from Co-60 γ-rays to 18 MV x-rays, although the dose per optical density decreases when the energy increases. The fading of the latent image before film processing is only 3% per month and the normalized sensitometric curve is not modified after a period of 51 days between irradiation and processing. Sets of films were mailed to three different institutes for irradiation and returned for processing and evaluation after more than two months in order to verify that mailing of irradiated and unprocessed films does not produce unwanted artefacts. Finally the feasibility of external audits with mailed film dosimetry is illustrated by comparison of beam profiles measured with films and ionization chambers in a polystyrene phantom. (author)

  3. Advances in biomedical dosimetry

    International Nuclear Information System (INIS)

    Full text: Radiation dosimetry, the accurate determination of the absorbed dose within an irradiated body or a piece of material, is a prerequisite for all applications of ionizing radiation. This has been known since the very first radiation applications in medicine and biology, and increasing efforts are being made by radiation researchers to develop more reliable, effective and safe instruments, and to further improve dosimetric accuracy for all types of radiation used. Development of new techniques and instrumentation was particularly fast in the field of both medical diagnostic and therapeutic radiology. Thus, in Paris in October the IAEA held the latest symposium in its continuing series on dosimetry in medicine and biology. The last one was held in Vienna in 1975. High-quality dosimetry is obviously of great importance for human health, whether the objectives lie in the prevention and control of risks associated with the nuclear industry, in medical uses of radioactive substances or X-ray beams for diagnostic purposes, or in the application of photon, electron or neutron beams in radiotherapy. The symposium dealt with the following subjects: General aspects of dosimetry; Special physical and biomedical aspects; Determination of absorbed dose; Standardization and calibration of dosimetric systems; and Development of dosimetric systems. The forty or so papers presented and the discussions that followed them brought out a certain number of dominant themes, among which three deserve particular mention. - The recent generalization of the International System of Units having prompted a fundamental reassessment of the dosimetric quantities to be considered in calibrating measuring instruments, various proposals were advanced by the representatives of national metrology laboratories to replace the quantity 'exposure' (SI unit = coulomb/kg) by 'Kerma' or 'absorbed dose' (unit joule/kg, the special name of which is 'gray'), this latter being closer to the practical

  4. Study for applying microwave power saturation technique on fingernail/EPR dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Park, Byeong Ryong; Choi, Hoon; Nam, Hyun Ill; Lee, Byung Ill [Radiation Health Research Institute, Seoul (Korea, Republic of)

    2012-10-15

    There is growing recognition worldwide of the need to develop effective uses of dosimetry methods to assess unexpected exposure to radiation in the event of a large scale event. One of physically based dosimetry methods electron paramagnetic resonance (EPR) spectroscopy has been applied to perform retrospective radiation dosimetry using extracted samples of tooth enamel and nail(fingernail and toenail), following radiation accidents and exposures resulting from weapon use, testing, and production. Human fingernails are composed largely of a keratin, which consists of {alpha} helical peptide chains that are twisted into a left handed coil and strengthened by disulphide cross links. Ionizing radiation generates free radicals in the keratin matrix, and these radicals are stable over a relatively long period (days to weeks). Most importantly, the number of radicals is proportional to the magnitude of the dose over a wide dose range (0{approx}30 Gy). Also, dose can be estimated at four different locations on the human body, providing information on the homogeneity of the radiation exposure. And The results from EPR nail dosimetry are immediately available However, relatively large background signal (BKS) converted from mechanically induced signal (MIS) after cutting process of fingernail, normally overlaps with the radiation induced signal (RIS), make it difficult to estimate accurate dose accidental exposure. Therefore, estimation method using dose response curve was difficult to ensure reliability below 5 Gy. In this study, In order to overcome these disadvantages, we measured the reactions of RIS and BKS (MIS) according to the change of Microwave power level, and researched about the applicability of the Power saturation technique at low dose.

  5. From ``micro`` to ``macro`` internal dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Fisher, D.R.

    1994-06-01

    Radiation dose is the amount of radiation energy deposited per unit mass of absorbing tissue. Internal dosimetry applies to assessments of dose to internal organs from penetrating radiation sources outside the body and from radionuclides taken into the body. Dosimetry is essential for correlating energy deposition with biological effects that are observed when living tissues are irradiated. Dose-response information provides the basis for radiation protection standards and risk assessment. Radiation interactions with living matter takes place on a microscopic scale, and the manifestation of damage may be evident at the cellular, multi-cellular, and even organ levels of biological organization. The relative biological effectiveness of ionization radiation is largely determined by the spatial distribution of energy deposition events within microscopic as well as macroscopic biological targets of interest. The spatial distribution of energy imparted is determined by the spatial distribution of radionuclides and properties of the emitted charged-particle radiation involved. The nonuniformity of energy deposition events in microscopic volumes, particularly from high linear energy transfer (LET) radiation, results in large variations in the amount of energy imparted to very small volumes or targets. Microdosimetry is the study of energy deposition events at the cellular level. Macrodosimetry is a term for conventional dose averaging at the tissue or organ level. In between is a level of dosimetry sometimes referred to as multi-cellular dosimetry. The distinction between these terms and their applications in assessment of dose from internally deposited radionuclides is described.

  6. Dosimetry Service

    CERN Multimedia

    2004-01-01

    We wish to remind the people who are invited to the dosimetry service to exchange the new CERN dosimeter that the hours are from Monday to Friday 8.30 to 11.00 and 14.00 to 16.00. http://service-rp-dosimetry.web.cern.ch/service-rp-dosimetry/

  7. Dosimetry of neutron irradiations

    International Nuclear Information System (INIS)

    Biological dosimetry of neutron irradiation appears to be of great difficulty due to the multiparametric aspect of the relative biological effectiveness and the heterogeneity of the neutron dose distribution. Dosimetry by sodium 24 activation which can be performed by means of portable radiameters appears to be very useful for early triage within the 3 h following neutron irradiation, whereas hematological dosimetry by slope and level analysis of the lymphocyte drop cannot be used in this case. Chromosomic aberration analysis allows to evaluate the neutron dose heterogeneity by the frequency measurement of acentric fragments not originating from the formation of dicentrics or rings. Finally, recent experimental data on large primate models (baboons) have shown that some plasma hemostasia factors appear to be reliable biological indicators and noticeable markers of the prognosis of neutron irradiation

  8. Dosimetry Control: Technic and methods. Proceedings of the international workshop 'Actual problems of dosimetry'

    International Nuclear Information System (INIS)

    There is a number of unsolved problems of both dosimetric and radiometric control, questions of the biological dosimetry, reconstruction of dozes of irradiation of the population at radiation incidents, which require coordination of efforts of scientists in various areas of a science. The submitted materials are grouped on five units: dosimetry engineering, biological dosimetry and markers of radiation impact, dosimetry of a medical irradiation, normative and measurement assurance of the dosimetric control, monitoring and reconstruction of dozes at radiation incidents

  9. Dosimetry in radiotherapy. V.1

    International Nuclear Information System (INIS)

    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

  10. Dosimetry in radiotherapy. V.2

    International Nuclear Information System (INIS)

    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

  11. Hippocampal dosimetry correlates with the change in neurocognitive function after hippocampal sparing during whole brain radiotherapy: a prospective study

    International Nuclear Information System (INIS)

    Whole brain radiotherapy (WBRT) has been the treatment of choice for patients with brain metastases. However, change/decline of neurocognitive functions (NCFs) resulting from impaired hippocampal neurogenesis might occur after WBRT. It is reported that conformal hippocampal sparing would provide the preservation of NCFs. Our study aims to investigate the hippocampal dosimetry and to demonstrate the correlation between hippocampal dosimetry and neurocognitive outcomes in patients receiving hippocampal sparing during WBRT (HS-WBRT). Forty prospectively recruited cancer patients underwent HS-WBRT for therapeutic or prophylactic purposes. Before receiving HS-WBRT, all participants received a battery of baseline neurocognitive assessment, including memory, executive functions and psychomotor speed. The follow-up neurocognitive assessment at 4 months after HS-WBRT was also performed. For the delivery of HS-WBRT, Volumetric Modulated Arc Therapy (VMAT) with two full arcs and two non-coplanar partial arcs was employed. For each treatment planning, dose volume histograms were generated for left hippocampus, right hippocampus, and the composite hippocampal structure respectively. Biologically equivalent doses in 2-Gy fractions (EQD2) assuming an alpha/beta ratio of 2 Gy were computed. To perform analyses addressing the correlation between hippocampal dosimetry and the change in scores of NCFs, pre- and post-HS-WBRT neurocognitive assessments were available in 24 patients in this study. Scores of NCFs were quite stable before and after HS-WBRT in terms of hippocampus-dependent memory. Regarding verbal memory, the corresponding EQD2 values of 0, 10, 50, 80 % irradiating the composite hippocampal structure with <12.60 Gy, <8.81, <7.45 Gy and <5.83 Gy respectively were significantly associated with neurocognitive preservation indicated by the immediate recall of Word List Test of Wechsler Memory Scale-III. According to logistic regression analyses, it was noted that dosimetric

  12. Chromosomal analysis and application of biological dosimetry in two cases of apparent over exposure; Analisis cromosomico y aplicacion de la dosimetria biologica en dos casos de aparente sobreexposicion

    Energy Technology Data Exchange (ETDEWEB)

    Guerrero C, C.; Brena V, M. [Departamento de Biologia, ININ A.P. 18-1027, 11801 Mexico D.F. (Mexico)

    2002-07-01

    The gamma radiation calibration curve of {sup 60} Co is used which was generated in the ININ Laboratory of Biology to calculate the exposure dose of two workers whose dosemeters marked values above of the limit allowed. The analysis indicates that in a first case, the aberrations frequency corresponded to the basal value, therefore there is not over exposure. The aberrations frequency of the second case is lightly above to the basal value and therefore the probability favors to what the physical dosimetry indicates. (Author)

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

    NARCIS (Netherlands)

    George, AL; Peat, HJ; Buma, AGJ

    2002-01-01

    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 Octob

  14. Physical and biological dosimetry at the barium sulphate-culture medium interface

    International Nuclear Information System (INIS)

    The present study suggests that a thin layer of Barium sulphate suspension forms an interface with tissues which results in high dose regions on both sides of the BSS-tissue interface when irradiated with 250 kVp X rays. The magnitude of dose increase depends on the density of the BSS. (U.K.)

  15. Cytokines-block micronucleus assay and its use for biological dosimetry

    International Nuclear Information System (INIS)

    The micronucleus (MN) assay in lymphocytes has been a convenient tool for the assessment of genetic damage induced by irradiation or chemical agents. This method is proved to be simpler, cheaper and rapid than the classical chromosome aberration assay. In the present paper, the influence factors in MN assay and established MN dose-response curve for X rays and γ rays has been studied

  16. 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

  17. Radiation therapy dosimetry system

    International Nuclear Information System (INIS)

    New therapeutic treatments generally aim to increase therapeutic efficacy while minimizing toxicity. Many aspects of radiation dosimetry have been studied and developed particularly in the field of external radiation. The success of radiotherapy relies on monitoring the dose of radiation to which the tumor and the adjacent tissues are exposed. Radiotherapy techniques have evolved through a rapid transition from conventional three-dimensional (3D) conformal radiation therapy to intensity-modulated radiation therapy (IMRT) treatments or radiosurgery and robotic radiation therapy. These advances push the frontiers in our effort to provide better patient care by improving the precision of the absorbed dose delivered. This paper presents state-of-the art radiation therapy dosimetry techniques as well as the value of integral dosimetry (INDOS), which shows promise in the fulfillment of radiation therapy dosimetry requirements. - highlights: • Pre-treatment delivery and phantom dosimetry in brachytherapy treatments were analyzed. • Dose distribution in the head and neck was estimated by physical and mathematical dosimetry. • Electron beam flattening was acquired by means of mathematical, physical and “in vivo” dosimetry. • Integral dosimetry (INDOS) has been suggested as a routine dosimetric method in all radiation therapy treatments

  18. Development of the FISH technique for biological dosimetry applications in the Gregorio Maranon General University Hospital

    International Nuclear Information System (INIS)

    Since 1989 cytogenetic analysis for dose estimation has been regularly used In the Gregorio Maranon General University Hospital (HGUGM) of Madrid on individuals suspected of having accidentally been exposed to ionizing radiation. The method used is the study of chromosomal aberrations found in lymphocytes of peripheral blood. The technique recommended by the IAEA in 1986 permits to establish a dicentrics/dose ratio through an effective dose calibration curve prepared in-vitro. This methodology of dose estimation presents serious limitations which can partially be eliminated by means of new molecular cytogenetic techniques, such as chromosomal painting through in-situ hybridization with fluorescence (FISH). At HGUGM, research work has been finished for standardization of the above mentioned technique including effective dose calibration curves, the utilization of adequate aberrations and the intercomparision of the results with other centres

  19. Biological and clinical dosimetry. Comprehensive eighteen-year report, July 1, 1964-June 30, 1982

    International Nuclear Information System (INIS)

    The objectives are to develop and apply primary and secondary dosimetric systems for measurements in the complex radiation fields currently in use for radiobiological research and advanced radiation oncology. The concept of local absorbed dose calorimetry continues to be applied and further developed using tissue equivalent and other materials. Aspects of a simplified approach to calorimetry with thermistors used as non-isolated-sensors in polystyrene are described. This approach also has the potential of giving accurate absolute absorbed dose measurements in situations where the irradiation time can be limited to about 20 minutes. A non-isolated-sensor calorimeter has also been constructed of A-150 tissue equivalent (TE) plastic. Comparison of the absorbed dose measurements with these two calorimeters, after correction for the known mass energy absorption coefficients, gives a direct determination of the thermal defect of A-150 plastic at different levels of free O2 content in the material. This will permit a study of various approaches to excluding oxygen. This type of calorimeter is presently also being constructed with solid-water-equivalent plastic, i.e., the material designated WT/SRI by Constantinou. Our previously successful isolated sensor calorimeters are still in operation. With the availability of both isolated and non-isolated absorbed dose calorimeters, of our parallel plate ionization chambers in similar material and geometry, and of specific commercial ion chambers, we are in a unique position not only to compare all of these systems but to examine critically basic assumptions in absorbed dose concepts and the correction factors used in different methodologies

  20. Study of dosimetry CT in Skull for pediatric patients

    International Nuclear Information System (INIS)

    The dose that receiving the patients in CT studies is the highest that can be received in a study of Radiology. If patients are children and we do studies with the same parameters as adults, they will receive a higher dose of radiation. This work seeks to expose the result of a dosimetric study on CT for children aged 0-15, carried out at the Hospital General Universitario de Santa Lucia in Cartagena during the year 2012. (Author)

  1. Proceedings of the international workshop 'Actual problems of dosimetry'

    International Nuclear Information System (INIS)

    Materials grouped to six main issues: dosimetry and radiometry equipment, dosimetry of the medical irradiation, standard and metrology support of dosimetric and radiometric control, biological dosimetry and markers of radiation effects, monitoring and reconstruction of radiation doses at radiation accidents and dosimetry of unionizing radiations

  2. Biological Dosimetry in Astronauts

    Science.gov (United States)

    George, Kerry; Cucinotta, Francis A.

    2007-01-01

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

  3. Biological studies of radiation effects

    Energy Technology Data Exchange (ETDEWEB)

    Lawrence, J.H.

    1949-11-16

    This paper discusses procedures for research on biological effects of radiation, using mouse tissue: activation trace analysis including methods and proceedures for handling samples before during and after irradiation; methods and procedures for ion exchange study; method of separation and recovery of copper, iron, zinc, cobalt, pubidium and cesium. Also included are studies of trace elements with radioactive isotopes: the distribution of cobalt 60, zinc 65, and copper 64 in the cytoplasm and nuclei of normal mice and those with tumors. 16 figs., 2 tabs.

  4. Dicentric chromosome aberration analysis using giemsa and centromere specific fluorescence in-situ hybridization for biological dosimetry: An inter- and intra-laboratory comparison in Indian laboratories

    International Nuclear Information System (INIS)

    To facilitate efficient handling of large samples, an attempt towards networking of laboratories in India for biological dosimetry was carried out. Human peripheral blood samples were exposed to 60Co γ-radiation for ten different doses (0–5 Gy) at a dose rate of 0.7 and 2 Gy/min. The chromosomal aberrations (CA) were scored in Giemsa-stained and fluorescence in-situ hybridization with centromere-specific probes. No significant difference (p>0.05) was observed in the CA yield for given doses except 4 and 5 Gy, between the laboratories, among the scorers and also staining methods adapted suggest the reliability and validates the inter-lab comparisons exercise for triage applications. - Highlights: • This is the first report from India on Networking for Biological Dosimetry preparedness using dicentric chromosomal (DC) aberration assay. • There is no significant difference in the in vitro dose response curve (Slope, Intercept, Curvature) constructed among the two labs. • No significant variation in the scoring of DC aberrations between the scorers irrespective of labs. • The DC results obtained by the labs from the Giemsa stained metaphase preparations were confirmed with centromere specific-FISH for further reliability and validity

  5. Cellular dosimetry in nuclear medicine imaging: training

    International Nuclear Information System (INIS)

    The radionuclides used in nuclear medicine imaging emit not only diagnostically useful photons, but also energy electron emissions, responsible for dose heterogeneity at the cellular level. The mean dose delivered to the cell nucleus by electron emissions of 99mTc, 123I, 111In, 67Ga, and 201Tl, has been calculated, for the cell nucleus, a cytoplasmic and a cell membrane distribution of radioactivity. This model takes into account both the self-dose which results from the radionuclide located in the target cell, and the cross-dose, which comes from the surrounding cells. The results obtained by cellular dosimetry (Dcel) have been compared with those obtained with conventional dosimetry (Dconv), by assuming the same amount of radioactivity per cell. Cellular dosimetry shows, for a cytoplasmic and a cell membrane distributions of radioactivity, that the main contribution to the dose to the cell nucleus, comes from the surrounding cells. On the other hand, for a cell nucleus distribution of radioactivity, the self-dose is not negligible and may be the main contribution. The comparison between cellular and conventional dosimetry shows that Dcel/Dconv ratio ranges from 0.61 and O.89, in case of a cytoplasmic and a cell membrane distributions of radioactivity, depending on the radionuclide and cell dimensions. Thus, conventional dosimetry slightly overestimates the mean dose to the cell nucleus. On the other hand, Dcel/Dconv ranges from 1.1 to 75, in case of a cell nucleus distribution of radioactivity. Conventional dosimetry may strongly underestimates the absorbed dose to the nucleus, when radioactivity is located in the nucleus. The study indicates that in nuclear medicine imaging, cellular dosimetry may lead to a better understanding of biological effects of radiopharmaceuticals. (authors)

  6. Pilot study on the application of computerised glow curve analysis in TL based personal dosimetry services

    International Nuclear Information System (INIS)

    Preliminary results of an inter-laboratory collaborative work on the application of computerised glow curve analysis to TL personal dosimetry are presented. Very simple analysis methods have proved to be useful for the evaluation of glow curves similar to those encountered in the dosimetric control of radiation workers. A first result obtained in the study has been the possibility of simplifying the TL working procedures by eliminating pre-annealing or pre-heating steps employed in conventional systems to avoid low temperature peaks. The presence of these unwanted peaks can be detected by the computerised evaluation methods, discriminating their contribution to the dosimetric TL data. (author)

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

    DEFF Research Database (Denmark)

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

    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. Room for improvement: results of a pilot study into routine in vivo dosimetry

    International Nuclear Information System (INIS)

    Full text: Quality assurance (QA) is a necessary part of radiation therapy, ensuring that radiation doses are accurately delivered and allowing optimal use of the therapeutic dose-window. Routine QA at the actual time of treatment by direct patient dose measurement (in vivo dosimetry) is rare as it has looked as though it would be imprecise, cumbersome and slow. However with the advent of devices for direct patient measurement (e.g., diodes, MOSFETs), in vivo dosimetry has become more viable and is routinely used in many centres around the world. We performed a pilot study to establish the feasibility of routine in vivo dosimetry on all patients treated at our centre. This is also in preparation for QA procedures to be performed on patients enrolled in dose-escalation studies. Scanditronix EDP-10 diodes were used connected to a DPD-510 electrometer, operated remotely from a PC running in-house developed software. All diodes were initially calibrated on a single treatment machine (Clinac 600C, 6 MV) for variation in dose per pulse, SSD, field size, surface temperature, beam incidence direction and treatment accessory. Entrance dose measurements were then made on 62 patients, and compared with estimates of entrance dose obtained from the treatment planning system. The calibration values obtained were consistent with previously reported values for Scanditronix EDP-10 diodes. A broad range of measured relative to predicted entrance doses was obtained, with the most significant errors being obtained on measurements of breast patients. For other patients, most readings were within 5% action limits. The main reasons identified for inconsistency in results is placement of the diodes in wedged fields, the influence of angle of incidence for oblique fields (particularly important for breast fields), and the temperature dependence of the diodes. This study has highlighted several areas of in vivo dosimetry that require particular attention if it is to be used in the routine

  9. Receptor studies in biological psychiatry

    International Nuclear Information System (INIS)

    Recent advances in the pharmacological treatment of endogenous psychosis have led to the development of biological studies in psychiatry. Studies on neurotransmitter receptors were reviewed in order to apply positron-emission tomograph (PET) for biological psychiatry. The dopamine (DA) hypothesis for schizophrenia was advanced on the basis of the observed effects of neuroleptics and methamphetamine, and DA(D2) receptor supersensitivity measured by PET and receptor binding in the schizophrenic brain. The clinical potencies of neuroleptics for schizophrenia were correlated with their abilities to inhibit the D2 receptor, and not other receptors. The σ receptor was expected to be a site of antipsychotic action. However, the potency of drugs action on it was not correlated with clinical efficacy. Haloperidol binds with high affinity to the σ receptor, which may mediate acute dystonia, an extrapyramidal side effect of neuroleptics. Behavioral and neurochemical changes induced by methamphetamine treatment were studied as an animal model of schizophrenia, and both a decrease of D2 receptor density and an increase of DA release were detected. The monoamine hypothesis for manic-depressive psychosis was advanced on the basis of the effect of reserpine, monoamine oxidase inhibitor and antidepressants. 3H-clonidine binding sites were increased in platelet membranes of depressive patients, 3H-imipramine binding sites were decreased. The GABAA receptor is the target site for the action of anxiolytics and antiepileptics such as benzodiazepines and barbiturates. Recent developments in molecular biology techniques have revealed the structure of receptor proteins, which are classified into two receptor families, the G-protein coupled type (D2) and the ion-channel type (GABAA). (J.P.N.)

  10. Dosimetry and Risk Assessment: Fundamental Concepts

    International Nuclear Information System (INIS)

    Radiation dosimetry is important for characterizing radiation exposures and for risk assessment. In a medical setting, dosimetry is important for evaluating the safety of administered radiopharmaceuticals and for planning the safe administration of therapeutic radionuclides. Environmental dosimetry helps establish the safety of radionuclide releases from electric power production and other human activities. Internal and external dosimetry help us understand the consequences of radiation exposure. The absorbed dose is the fundamental quantity in radiation dosimetry from which all other operational values in radiation protection are obtained. Equivalent dose to tissue and effective dose to the whole body are derivatives of absorbed dose and constructs of risk. Mathematical systems supported by computer software facilitate dose calculations and make it possible to estimate internal dose based on bioassay or other biokinetic data. Risk coefficients for radiation-induced cancer rely primarily on data from animal studies and long-term observations of the Hiroshima and Nagasaki bomb survivors. Low-dose research shows that mechanisms of radiation interactions with tissue are dose-dependent, but the resulting biological effects are not necessarily linear with absorbed dose. Thus, the analysis of radiation effects and associated risks must account for the influences of microscopic energy distributions at the cellular level, dose-rate, cellular repair of sub-lethal radiation damage, and modifying factors such as bystander effects, adaptive response, and genomic instability.

  11. Use of thermoluminescent dosimetry in gamma radiation fields studies

    International Nuclear Information System (INIS)

    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)

  12. Quantitative autoradiography of radionuclides in biological tissues by high resolution nuclear analysis: application in radio-toxicology and dosimetry

    International Nuclear Information System (INIS)

    In the framework of radiation damage on cells in living organisms an auto-radiograph, based on the STIC method, has been developed for the particles detection. This apparatus associates a thin scintillator with a photosensitive detector (CCD). The design and the performance of this well adapted tool for low activity biological samples study, are described. (A.L.B.)

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

    International Nuclear Information System (INIS)

    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 104rad), while the lactose response extends to a higher range from 1 to 104 Gy (102-106 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 102-105 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)

  14. Several dosimetry studies in the fast neutron source reactor ''YAYOI''

    International Nuclear Information System (INIS)

    Neutron flux and spectra in the YAYOI core-center field have been well characterized through the detector intercomparison studies. Spectra are summarized in an efficient parameter representation form which is useful for neutron dose evaluation. An intermediate neutron field with near 1/E spectrum shape has been developed in the center of the octagonal lead pile driven by YAYOI core. Calculated neutron flux and spectra by two dimensional transport code have been in good agreement with the experimental results within +- 10% above 0.2 MeV and +- 20% below 0.2 MeV. Its usefulness as a standard neutron field is discussed. Absorbed dose measurements have been also carried out at the core-center field with three different techniques; calorimeter, Fricke-dosimeter and foil detector set used with a thermo-luminescent dosimeter, and a good agreement has been obtained especially about the neutron dose value

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

    International Nuclear Information System (INIS)

    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)

  16. A study on dosimetry for child in dentistry, 2

    International Nuclear Information System (INIS)

    Recently, we use X-ray inspection very frequently and take a X-ray picture by various technique 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. Though the exposure dose became to social problem, it is demanded to play consideration to X-ray technique for children because of higher sensitivity than adult. 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 first report is two dimension, 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 technique. 4. The exposure dose at child tended to higher than adult by all technique. (author)

  17. Inhomogeneity in optical properties of rat brain: a study for LLLT dosimetry

    Science.gov (United States)

    Sousa, Marcelo V. P.; Prates, Renato; Kato, Ilka T.; Sabino, Caetano P.; Yoshimura, Tania M.; Suzuki, Luis C.; Magalhães, Ana C.; Yoshimura, Elisabeth M.; Ribeiro, Martha S.

    2013-03-01

    Over the last few years, low-level light therapy (LLLT) has shown an incredible suitability for a wide range of applications for central nervous system (CNS) related diseases. In this therapeutic modality light dosimetry is extremely critical so the study of light propagation through the CNS organs is of great importance. To better understand how light intensity is delivered to the most relevant neural sites we evaluated optical transmission through slices of rat brain point by point. We experimented red (λ = 660 nm) and near infrared (λ = 808 nm) diode laser light analyzing the light penetration and distribution in the whole brain. A fresh Wistar rat (Rattus novergicus) brain was cut in sagittal slices and illuminated with a broad light beam. A high-resolution digital camera was employed to acquire data of transmitted light. Spatial profiles of the light transmitted through the sample were obtained from the images. Peaks and valleys in the profiles show sites where light was less or more attenuated. The peak intensities provide information about total attenuation and the peak widths are correlated to the scattering coefficient at that individual portion of the sample. The outcomes of this study provide remarkable information for LLLT dose-dependent studies involving CNS and highlight the importance of LLLT dosimetry in CNS organs for large range of applications in animal and human diseases.

  18. 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.

  19. Dosimetry study comparing NCS report-2 versus IAEA TRS-398 protocol for high energy photon beams

    International Nuclear Information System (INIS)

    In this work a dosimetry study is presented in which the results of absorbed dose determined at reference condition according to the IAEA TRS-398 protocol and the NCS report-2 are compared. The IAEA TRS-398 protocol for absorbed dose calibration is based on ionization chamber having absorbed dose to water calibration factor Ndw, while the NCS-2 dosimetry report for absorbed dose calibration is based on an ionization chamber having air- kerma calibration factor Nk. This study shows that the absorbed dose which is calculated with The IAEA TRS-398 formalisms is higher than that calculated with NCS report-2 formalisms within range from 0.4 to 0.9% in cobalt-60 beam as sensed by different ionization chambers, and from 0.2 to 1.1% for different higher energy photon beams of 6, 8 and 18 MV. The chambers used are PTW 30001, 30004, and NE-2571; which have calibration factors Nk and Ndw traceable to the BIPM (Bureau International des Poids et Mesures)

  20. Nineteenth nuclear accident dosimetry intercomparison study, August 9-13, 1982

    International Nuclear Information System (INIS)

    The Nineteenth Nuclear Accident Dosimetry Intercomparison Study was held August 9 to 13, 1982, at the Oak Ridge National Laboratory using the Health Physics Research Reactor operated in the pulse mode to simulate nuclear criticality accidents. Participants from eight organizations measured neutron and gamma doses at air stations and on phantoms for three different shielding conditions. Measured results were compared to nuclear industry guidelines for criticality accident dosimeters which suggest accuracies of +-25% for neutron dose and +-20% for gamma dose. Seventy-two percent of the neutron dose measurements using foil activation, sodium activation, hair sulfur activation, and thermoluminescent methods met the guidelines while less than 40% of the gamma dose measurements were within +-20% of reference values. The softest neutron energy spectrum (also lowest neutron/gamma dose ratio) provided the most difficulty in measuring neutron and gamma doses. Results of this study indicate the need for continued intercomparison and testing of nuclear accident dosimetry systems and for training of evaluating personnel. 14 references, 7 figures, 16 tables

  1. Dating by fission track method: study of neutron dosimetry with natural uranium thin films

    International Nuclear Information System (INIS)

    Fission track dating is described, focalizing the problem of the decay constant for spontaneous fission of 238 U and the use of neutron dosimetry in fission track analysis. Experimental procedures using thin films of natural uranium as neutron dosimeters and its results are presented. The author shows a intercomparison between different thin films and between the dosimetry with thin film and other dosimetries. (M.V.M.). 52 refs, 12 figs, 9 tabs

  2. Design, characterization and use of replicate human upper airways for radon dosimetry studies

    International Nuclear Information System (INIS)

    The size distribution of inhaled radon progeny aerosols is a significant factor in dosimetry. The role of the airways above the trachea is an important determinant of the respiratory distribution of both attached and unattached progeny aerosols. In order to provide information on the effect of particle size and breathing conditions on the overall and local deposition, we have developed a method to produce a replicate airway model from an in vivo magnetic resonance imaging coronal scan. The model consists of a sandwich of methacrylate elements, each element having the thickness of the scan interval. The transition between successive scan outlines traced on the front and back surfaces of each element is handsculpted in the plastic. The hollow model of the nasal passages thus produced has been characterized both morphologically and fluid-mechanically and has a flow resistance typical of a normal adult. The model has several distinct advantages for studies of radon progeny aerosol deposition. After exposure to a radioaerosol (or to an aerosol of an otherwise measurable substance) the individual elements can be separated to determine local deposition. The dimensions of specific upper-airway regions can be changed by replacing a small number of elements. The model has been incorporated in an exposure system for determining overall nandregional deposition of aerosols whose median diameter is approximately 1.7 nm. Measurements at several flow rates are presented to demonstrate use of the model in radon dosimetry. The model should also be useful for determining the airway deposition of other environmental aerosols

  3. Biological dosimetry of patients with differenced carcinoma of thyroid treated with Iodine-131; Dosimetria biologica de pacientes con carcinoma diferenciado de tiroides tratados con Iodo-131

    Energy Technology Data Exchange (ETDEWEB)

    Vallerga, M. B.; Rojo, A.M.; Taja, M.R.; Deluca, G.; Di Giorgio, M. [Autoridad Regulatoria Nuclear Av. Del Libertador 8250 (C1429BNP). Buenos Aires (Argentina); Fadel, A. [Hospital General de Agudos Dr. Carlos Durand Av. Diaz Velez 5044. Buenos Aires (Argentina); Cabrejas, M.; Valdivieso, C. [Hospital de Clfnicas Jose de San Martin Av. Cordoba 2351 (CP1120). Buenos Aires (Argentina)]. e-mail: mvallerg@cae.arn.gov.ar

    2006-07-01

    The administration of I-131 to patient with Differentiated Thyroid Carcinoma (CaDiT) it is used inside the therapeutic outline as later step to the thyroidectomy. However, the good activity to give is of difficult determination due to factors such as, the variability in the capacity of tumoral reception of the I-131, distribution of the pharmaceutical, physiologic status, other associate pathologies, grade of advance of the illness, and previous treatments. Additionally, the activity to administer is dependent of the dose of tolerance in the healthy tissues; superior dose to 2 Gy in bone marrow, its could drive to myelotoxicity. At the moment, the form more extended of administration it is the empiric prescription that considers clinical parameters and of laboratory for their determination. Presently work, the protocol of applied treatment incorporates the evaluation for internal dosimetry and biological dosimetry to estimate absorbed dose in bone marrow. The biological estimate of the dose of these patients is based on the quantification of chromosomal aberrations whose frequency is referred to a curve-dose response in which the lymphocytes is irradiated in vitro with I-131, allowing to determine the in vivo dose to the patient's circulating lymphocytes. The objective of the present work is to determine the applicability of different cytogenetic essays in the estimate of the absorbed dose to the whole body or specific organs. Three patients were evaluated with CaDiT. Their treatment protocol consisted on a tracer administration of radioactive iodine of 74 - 111 MBq (2 - 3 mCi) and a therapy 7,4 - 11,1 GBq (200 - 300 mCi). Previous to the tracer administration and 8 days post-therapeutic administration took samples of veined blood that were evaluated by biological dosimetry by means of the application of the techniques: conventional cytogenetic Micronucleus and FISH (Hybridization in situ by Fluorescence). Starting from the frequencies of observed chromosomal

  4. Dosimetry Service

    CERN Multimedia

    2005-01-01

    Please remember to read your dosimeter at least once a month. Regular read-outs are vital to ensure that your personal dose is periodically monitored. Dosimeters should be read even if you have not visited the controlled areas. Dosimetry Service - Tel. 72155 http://cern.ch/rp-dosimetry

  5. Dosimetry Service

    CERN Multimedia

    Dosimetry Service

    2005-01-01

    Please remember to read your dosimeter at least once a month. Regular read-outs are vital to ensure that your personal dose is periodically monitored. Dosimeters should be read even if you have not visited the controlled areas. Dosimetry Service Tel. 7 2155 http://cern.ch/rp-dosimetry

  6. Dosimetry Service

    CERN Multimedia

    2005-01-01

    Please remember to read your dosimeter at least once a month. Regular read-outs are vital to ensure that your personal dose is periodically monitored. Dosimeters should be read even if you have not visited the controlled areas. Dosimetry Service - Tel. 7 2155 http://cern.ch/rp-dosimetry

  7. ESR Dosimetry

    International Nuclear Information System (INIS)

    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

  8. Dosimetria esporular: Bacillus subtilis TKJ6312 como biossensor de radiação solar biologicamente ativa Spore dosimetry: Bacillus subtilis TKJ6312 as biosensor of biologically effective solar radiation

    Directory of Open Access Journals (Sweden)

    Marcelo Barcellos da Rosa

    2009-01-01

    Full Text Available Since 2000, spore dosimetry and spectral photometry have been performed in parallel at the Southern Space Observatory, São Martinho da Serra (Southern Brazil. A comparative study involving data from Punta Arenas - Chile (53.2º S, São Martinho da Serra (29.5º S, Padang - Indonesia (0.9ºS, Brussels - Belgium (50.9º N and Kiyotake - Japan (31.9º N from 2000 to 2006 is presented. The Spore Inactivation Doses presented the higher values in summer (973 ± 73 for Punta Arenas and 4,369 ± 202 for São Martinho da Serra, as well 1,402 ± 170 and 3,400 ± 1,674 for Brussels and Kiyotake, respectively. The simplicity, robustness and high resistance of bacterial spores makes the biosensor an potential biological tool for UV-B monitoring.

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

    International Nuclear Information System (INIS)

    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

  10. Dosimetry and dose planning in boron neutron capture therapy : Monte Carlo studies

    Energy Technology Data Exchange (ETDEWEB)

    Koivunoro, H.

    2012-07-01

    Boron neutron capture therapy (BNCT) is a biologically targeted radiotherapy modality. So far, 249 cancer patients have received BNCT at the Finnish Research Reactor 1 (FiR 1) in Finland. The effectiveness and safety of radiotherapy are dependent on the radiation dose delivered to the tumor and healthy tissues, and on the accuracy of the doses. At FiR 1, patient dose calculations are performed with the Monte Carlo (MC) -based treatmentplanning system (TPS), Simulation Environment for Radiotherapy Applications (SERA). Initially, BNCT was applied to head and neck cancer, brain tumors, and malignant melanoma. To evaluate the applicability of the new target tumors for BNCT, calculation dosimetry studies are needed. So far, clinical BNCT has been performed with the neutrons from a nuclear reactor, while an accelerator based neutron sources applicable for hospital operation would be preferable. In this thesis, BNCT patient dose calculation practice in Finland was evaluated against reference calculations and experimental data in several cases. Calculations with two TPSs applied in clinical BNCT were compared. The suitability of the deuterium-deuterium (DD) and deuterium-tritium (D-T) fusion reaction-based compact neutron sources for BNCT were evaluated. In addition, feasibility of BNCT for noninvasive liver tumor treatments was examined. The deviation between SERA and the reference calculations was within 4% in the phantoms studied and in a brain cancer patient model elsewhere, except on the phantom or skin surface, for the boron, nitrogen, and photon dose components. These dose components produce 99% of the tumor dose and > 90% of the healthy tissue dose at points of relevance for treatment at the FiR 1 facility. The reduced voxel cell size ({<=} 0.5 cm) in the SERA edit mesh improved calculation accuracy on the surface. The erratic biased fastneutron run option in SERA led to significant underestimation (up to 30-60%) of the fastneutron dose, while more accurate fast

  11. Radiation cytogenetic in vitro studies on human donors in the development of a suitable biological dosimeter

    International Nuclear Information System (INIS)

    The final report is on the work carried out under the Agency research contract 3173/RB entitled ''Radiation cytogenetic in vitro studies on human donors in the development of a suitable biological dosimeter'', at the Clinical Hospital Centre ''Zvezdara'' in Belgrade, Yugoslavia. In co-operation and co-ordination dissemination with an international team of cytogeneticists under the IAEA CRP, the development of a suitable biological dosimetry system has been accomplished at the national institute to assist reliably in the absorbed radiation-dose assessment of accidentally-over-exposed personnel. The quantitative yield of asymmetrical chromosomal aberrations, such as dicentrics, rings and fragments consequent to exposure(s) to radiation overdose, help in such estimation of vital prognostic and radiation protection significance. This biological dosimeter system is particularly essential where the exposed person was not wearing any physical dosemeter during the accident. Prerequisite for implementation of an effective biological dosimetry is the availability of a reliable standard dose-response curve and an adherence to a protocol for lymphocytic chromosome analysis in first division phase of lymphocytes. The validation of the reported biological dosimeter is established through its successful analysis of a simulated over-exposure incident, with the associated error of less than 10%. Analytical cytogenetic methods for whole- and part-body acute exposures have been discussed. Part of the results have been reported in the publications under the CRP concerned

  12. Summary and analsysis of the 1986 ORNL personnel dosimetry intercomparison study

    International Nuclear Information System (INIS)

    The Twelfth Personnel Dosimetry Intercomparison Study was conducted at the Oak Ridge National Laboratory (ORNL) during April 14 to 17, 1986. Objectives of this study were to determine neutron dosimeter performance characteristics at neutron dose equivalent levels near the minimum specified for accreditation testing programs and to provide several radiation fields different from those that have been considered in prior ORNL intercomparisons. Dosimeter badges from 49 participating organizations were mounted on Lucite block phantoms and exposed to six mixed-radiation fields (five using the Health Physics Research Reactor and one using a PuBe source) with neutron dose equivalents of about 1.5 mSv and gamma dose equivalents between 0.04 and 5.37 mSv. Results of this study indicated that participants had no difficulty obtaining measurable indication of neutron exposure at dose equivalent levels of about 1.5 mSv. Average neutron results for all dosimeter types were within approximately 60% of reference values with hard spectra being more accurately measured than soft spectra. Considering all irradiations, albedo and direct interaction TLD systems provided about the same performance characteristics. With regard to precision, about 58% of the reported neutron results had single standard deviations within 10% at the means which indicates that precision was not a problem relative to accuracy for over half of the participants. Average gamma results varied from 0.98 to 2.22 times reference values for all exposures with TLD systems being more accurate than film. Some participants, especially those using film, had difficulty obtaining measurable indication of gamma exposures at dose equivalent levels lower than 0.09 mSv. About 69% of all neutron results and 77% of all gamma results met regulatory standards for measurement accuracy and approximately 65% of all neutron data satisfied national dosimetry accreditation criteria for accuracy plus precision. 18 refs., 1 fig., 30 tabs

  13. Summary and analsysis of the 1986 ORNL personnel dosimetry intercomparison study

    Energy Technology Data Exchange (ETDEWEB)

    Swaja, R.E.; Weng, P.S.; Sims, C.S.; Yeh, S.H.

    1987-04-01

    The Twelfth Personnel Dosimetry Intercomparison Study was conducted at the Oak Ridge National Laboratory (ORNL) during April 14 to 17, 1986. Objectives of this study were to determine neutron dosimeter performance characteristics at neutron dose equivalent levels near the minimum specified for accreditation testing programs and to provide several radiation fields different from those that have been considered in prior ORNL intercomparisons. Dosimeter badges from 49 participating organizations were mounted on Lucite block phantoms and exposed to six mixed-radiation fields (five using the Health Physics Research Reactor and one using a PuBe source) with neutron dose equivalents of about 1.5 mSv and gamma dose equivalents between 0.04 and 5.37 mSv. Results of this study indicated that participants had no difficulty obtaining measurable indication of neutron exposure at dose equivalent levels of about 1.5 mSv. Average neutron results for all dosimeter types were within approximately 60% of reference values with hard spectra being more accurately measured than soft spectra. Considering all irradiations, albedo and direct interaction TLD systems provided about the same performance characteristics. With regard to precision, about 58% of the reported neutron results had single standard deviations within 10% at the means which indicates that precision was not a problem relative to accuracy for over half of the participants. Average gamma results varied from 0.98 to 2.22 times reference values for all exposures with TLD systems being more accurate than film. Some participants, especially those using film, had difficulty obtaining measurable indication of gamma exposures at dose equivalent levels lower than 0.09 mSv. About 69% of all neutron results and 77% of all gamma results met regulatory standards for measurement accuracy and approximately 65% of all neutron data satisfied national dosimetry accreditation criteria for accuracy plus precision. 18 refs., 1 fig., 30 tabs.

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

    International Nuclear Information System (INIS)

    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

  15. Personal dosimetry in terms of HP(3):Monte Carlo and experimental studies

    International Nuclear Information System (INIS)

    Hp(3) has been defined as the operational quantity for eye lens dosimetry. Hp(3)/ka conversion coefficients were evaluated at the GSF (Germany) in a 30 x 30 x 15 x cm3 4-elements ICRU slab phantom for various energies and incident angles through Monte Carlo. The ISO report 12,794 suggests to employ a PMMA water filled phantom, of the same dimensions, for dosemeter calibration in terms of Hp(3). The present paper briefly summarises the main aspects of a study carried out at ENEA-Radiation Protection Inst. (Bologna (Italy)) to provide practical procedures for the calibration of dosemeters in terms of Hp(3). Tabulations of a new set conversion coefficients and air kerma backscatter factors are provided as a function of energy and incident angle. The paper demonstrates that a more accurate approach to the dosimetric assessment in terms of Hp(3) could be rather simply introduced employing a reduced phantom. (authors)

  16. Extension of Radiochromic Film Dosimetry to Three Dimensions: A Feasibility Study

    International Nuclear Information System (INIS)

    The feasibility of measuring dose distributions in three-dimensions using Gafchromic EBT film was studied. A stack of film was used as tomographic dosimeter. The response of film (4x4 cm2) placed between a stack of Gafchromic EBT films and slabs of polystyrene phantom was tested. Differences in film response for two different photon beam qualities, 6 MV and 25 MV, were observed. Measurements with 6 MV beam quality revealed that for different field sizes and depths there were no changes in response of EBT Gafchromic film when placed between polystyrene plates or sandwiched between other films. However, in the case of 25 MV beam quality, a statistically significant over-response was found for film placed in stack. We conclude that stacked-film dosimetry is feasible at 6 MV. For 25 MV photon beam quality the stack of films showed different properties than the polystyrene slabs of the same height

  17. Dosimetry in radionuclide therapy

    International Nuclear Information System (INIS)

    While it is known that therapeutic effects of radionuclides are due to absorbed radiation dose and to radiosensitivity, individual dosimetry in 'Gy' is practiced rarely in clinical Nuclear Medicine but 'doses' are described in 'mCi' or 'MBq', which is only indirectly related to 'Gy' in the target. To estimate 'Gy', the volume of the target, maximum concentration of the radiopharmaceutical in it and residence time should be assessed individually. These parameters can be obtained usually only with difficulty, involving possibly also quantitative SPET or PET, modern imaging techniques (sonography, CT, MRT), substitution of y- or positron emitting radiotracers for β-emitting radiopharmaceuticals as well as whole-body distribution studies. Residence time can be estimated by obtaining data on biological half-life of a comparable tracer and transfer of these data in the physical characteristics of the therapeutic agent. With all these possibilities for gross dosimetry the establishment of a dose-response-relation should be possible. As distribution of the radiopharmaceutical in lesions is frequently inhomogenous and microdosimetric conditions are difficult to assess in vivo as yet, it could be observed since decades that empirically set, sometimes 'fixed' doses (mCi or MBq) can also be successful in many diseases. Detailed dosimetric studies, however, are work- and cost-intensive. Nevertheless, one should be aware at a time when more sophisticated therapeutic possibilities in Nuclear Medicine arise, that we should try to estimate radiation dose (Gy) in our new methods even as differences in individual radiosensitivity cannot be assessed yet and studies to define individual radiosensitivity in lesions should be encouraged. (author)

  18. Biological dosimetry: benefit of a serial biological profile in major radiation accidents; Dosimetrie biologique: interet de l`analyse d`un bilan biologique multiparametrique lors d`une surexposition accidentelle

    Energy Technology Data Exchange (ETDEWEB)

    Martin, S.; Denis, J.; Agay, D.; Abadie, B.; Serbat, A.; Fatome, M.

    1995-12-31

    Supposing there is, for each irradiated individual, a specific biological profile, the kinetics and multi-parametric statistical analysis of which allows to sort irradiated. The parameters of this serial biological profile were researched using a primate experimental model. A biological profile bas been defined which allows as soon as the 6. hour and during 72 hours, to point out doses > 4 Gy and/or prognosis. (author). 2 refs.

  19. 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.

  20. ISDD: A Computational Model of Particle Sedimentation, Diffusion and Target Cell Dosimetry for In Vitro Toxicity Studies

    Energy Technology Data Exchange (ETDEWEB)

    Hinderliter, Paul M.; Minard, Kevin R.; Orr, Galya; Chrisler, William B.; Thrall, Brian D.; Pounds, Joel G.; Teeguarden, Justin G.

    2010-11-30

    . 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.

  1. Dosimetry Service

    CERN Multimedia

    Dosimetry Service

    2004-01-01

    We wish to remind the people who are invited to the dosimetry service to exchange the new CERN dosimeter that the hours are from Monday to Friday 8:30 to 11:00 and 14:00 to 16:00. For all other services we are at your disposition from 8:30 to 12:00 and 14:00 to 17:00. Do not forget to read your dosimeter. A regular read-out is indispensable in order to ensure a periodic monitoring of personal dose. This read-out should be done during the first week of every month. Thank you for your cooperation. The personnel of the Dosimetry Service wish you a Merry Christmas and a Happy New Year. Dosimetry Service Tel. 767 21 55 http://cern.ch/rp-dosimetry

  2. Dosimetry methods

    DEFF Research Database (Denmark)

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

    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....

  3. Dosimetry Service

    CERN Multimedia

    Dosimetry Service

    2005-01-01

    Please remember to read your dosimeter at least once every month. A regular read-out is indispensable to ensure periodic monitoring of your personal dose. You must read your dosimeter even if you have not visited the controlled areas. Film badges are no longer valid at CERN and holders of film badges are no longer allowed to enter the controlled radiation areas or work with a source. Dosimetry Service Tel. 72155 http://cern.ch/rp-dosimetry

  4. Radiation dosimetry and radiation biophysics

    International Nuclear Information System (INIS)

    Radiation dosimetry and radiation biophysics are two closely integrated programs whose joint purpose is to explore the connections between the primary physical events produced by radiation and their biological consequences in cellular systems. The radiation dosimetry program includes the theoretical description of primary events and their connection with the observable biological effects. This program also is concerned with the design and measurement of physical parameters used in theory or to support biological experiments. The radiation biophysics program tests and uses the theoretical developments for experimental design, and provides information for further theoretical development through experiments on cellular systems

  5. Radiation dosimetry and radiation biophysics

    International Nuclear Information System (INIS)

    Radiation dosimetry and radiation biophysics are two closely integrated programs whose joint purpose is to explore the connections between the primary physical events produced by radiation and their biological consequences in cellular systems. The radiation dosimetry program includes the theoretical description of primary events and their connection with the observable biological effects. This program also is concerned with design and measurement of those physical parameters used in the theory or to support biological experiments. The radiation biophysics program tests and makes use of the theoretical developments for experimental design. Also, this program provides information for further theoretical development through experiments on cellular systems

  6. The sensitivity analysis of tooth enamel to the absorbed dose for the application to EPR dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Dae Seok; Lee, Kun Jai [Korea Advanced Institute of Science and Technology, Taejon (Korea, Republic of); Cho, Young Hwan [KAERI, Taejon (Korea, Republic of)

    2002-10-01

    Electron Paramagnetic Resonance (EPR) spectroscopy is one of the methods applicable to retrospective dosimetry. The retrospective dosimetry is a process that is a part of dose reconstruction for estimation of exposed dose occurred years before the estimation. Many techniques can be used to the retrospective dosimetry. As a physical method, EPR analysis of biological material measures the quantity of free radicals generated in the material from the interaction of radiation and material. Since the later 80s, in many countries, EPR dosimetry with tooth enamel has been studied and applied for the retrospective dosimetry. In the consideration of the biological materials for EPR dosimetry, human fingernail, hair, bone and tooth are generally considered. The tooth can be separated as enamel, dentine and cementum. Among the three parts, enamel shows the best sensitivity to the absorbed dose and is most widely used. In this study, the characteristics of tooth enamel for EPR dosimetry is examined and experimented. At the experiment, for easy separation, tooth was cut into 4 parts and then each part is treated by ultrasonic vibration in NaOH liquid to reduce mechanically induced noise in the corresponding signal. After the separation of the enamel from dentine, background EPR signal is measured and then radiation-induced EPR spectrum is estimated.

  7. Activities developed by the biological dosimetry laboratory of the Autoridad Regulatoria Nuclear - ARN of Argentina; Actividades desarrolladas por el laboratorio de dosimetria biologica de la Autoridad Regulatoria Nuclear de Argentina

    Energy Technology Data Exchange (ETDEWEB)

    Radl, A.; Sapienza, C.E.; Taja, M.R.; Bubniak, R.; Deminge, M.; Di Giorgio, M., E-mail: csapienza@arn.gob.ar [Autoridad Regulatoria Nuclear (ARN), Buenos Aires (Argentina)

    2013-07-01

    Biological dosimetry (DB) allows to estimate doses absorbed in individuals exposed to ionizing radiation through the quantification of stable and unstable chromosome aberrations (SCA and UCA). The frequency of these aberrations is referred to a calibration dose response curve (in vitro) to determine the doses of the individual to the whole body. The DB is a necessary support for programs of national radiation protection and response systems in nuclear or radiological emergencies in the event of accidental or incidental, single overexposure or large scale. In this context the Laboratory of Dosimetry Biological (LDB) of the Authority Regulatory Nuclear (ARN) Argentina develops and applies different dosimeters cytogenetic from four decades ago. These dosimeters provide a fact more within the whole of the information necessary for an accidental, complementing the physical and clinical dosimetry exposure assessment. The most widely used in the DB biodosimetric method is the quantification of SCA (dicentrics and rings Central) from a sample of venous blood. The LDB is accredited for the trial, under rules IRAM 301: 2005 (ISO / IEC 17025: 2005) and ISO 19238:2004. Test applies to the immediate dosimetry evaluation of acute exposures, all or a large part of the body in the range 0,1-5 Gy. In this context the LDB is part of the Latin American network of DB (LBDNet), BioDoseNet-who and response system in radiological emergencies and nuclear IAEA-RANET, being enabled to summon the LBDNet if necessary.

  8. Radiation dosimetry in radiotherapy with internal emitters

    Energy Technology Data Exchange (ETDEWEB)

    Stabin, Michael G. [Oak Ridge Inst. for Science and Education, TN (United States)

    1997-12-31

    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

  9. 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

  10. Nuclear biological studies in France

    International Nuclear Information System (INIS)

    On the occasion of a colloquium on radiobiological research programmes, a number of documents dealing with French accomplishments and projects in this field were collected together. We felt that it would be useful to assemble these papers in one report; although they are brief and leave gaps to be filled in, they provide certain data, give an overall view of the situation, and can also suggest a rough plan for the general policy to adopt in the field of 'nuclear' biological research; i.e. research based on the nuclear tracer method or devoted to the action of ionising radiations. (author)

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

    International Nuclear Information System (INIS)

    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 201Tl and 111In-antimyosin. Thus Nuclear Medicine studies do not bear a higher radiation risk than the often used X-ray studies in transplant patients

  12. 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.

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

    Science.gov (United States)

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

    2013-08-01

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

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

    International Nuclear Information System (INIS)

    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)

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

    International Nuclear Information System (INIS)

    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.)

  16. A review of contributions of human tissue studies to biokinetics, bio-effects and dosimetry of plutonium in man

    International Nuclear Information System (INIS)

    This paper briefly reviews the contributions made by human tissue studies to improved understanding of the biokinetics, dosimetry and potential bio-effects of plutonium in man. It includes consideration of tissue donations from both environmental and occupational populations, along with a brief history of human experience with plutonium and consideration of the bio-ethical aspects of post-mortem human tissue sampling. (authors)

  17. (41)Ca in Tooth Enamel. Part II: A means for retrospective biological neutron dosimetry in atomic bomb survivors.

    Science.gov (United States)

    Rühm, W; Wallner, A; Cullings, H; Egbert, S D; El-Faramawy, N; Faestermann, T; Kaul, D; Knie, K; Korschinek, G; Nakamura, N; Roberts, J; Rugel, G

    2010-08-01

    (41)Ca is produced mainly by absorption of low-energy neutrons on stable (40)Ca. We used accelerator mass spectrometry (AMS) to measure (41)Ca in enamel of 16 teeth from 13 atomic bomb survivors who were exposed to the bomb within 1.2 km from the hypocenter in Hiroshima. In our accompanying paper (Wallner et al., Radiat. Res. 174, 000-000, 2010), we reported that the background-corrected (41)Ca/Ca ratio decreased from 19.5 x 10(-15) to 2.8 x 10(-15) with increasing distance from the hypocenter. Here we show that the measured ratios are in good correlation with gamma-ray doses assessed by electron paramagnetic resonance (EPR) in the same enamel samples, and agree well with calculated ratios based on either the current Dosimetry System 2002 (DS02) or more customized dose estimates where the regression slope as obtained from an errors-in-variables linear model was about 0.85. The calculated DS02 neutron dose to the survivors was about 10 to 80 mGy. The low-energy neutrons responsible for (41)Ca activation contributed variably to the total neutron dose depending on the shielding conditions. Namely, the contribution was smaller (10%) when shielding conditions were lighter (e.g., outside far away from a single house) and was larger (26%) when they were heavier (e.g., in or close to several houses) because of local moderation of neutrons by shielding materials. We conclude that AMS is useful for verifying calculated neutron doses under mixed exposure conditions with gamma rays. PMID:20681781

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

    International Nuclear Information System (INIS)

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

  19. 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.

  20. 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)

  1. Dosimetry standards

    International Nuclear Information System (INIS)

    The following leaflets are contained in this folder concerning the National Physical Laboratory's measurement services available in relation to dosimetry standards: Primary standards of X-ray exposure and X-ray irradiation facilities, X-ray dosimetry at therapy levels, Protection-level X-ray calibrations, Therapy-level gamma-ray facility, Fricke dosemeter reference service, Low-dose-rate gamma-ray facility, Penetrameter and kV meter calibration, Measurement services for radiation processing, Dichromate dosemeter reference service, Electron linear accelerator. (U.K.)

  2. Online in vivo dosimetry in high dose rate prostate brchytherapy with MOSkin detectors: In phantom feasibility study

    International Nuclear Information System (INIS)

    MOSkin detectors were studied to perform real-time in vivo dose measurements in high dose rate prostate brachytherapy. Measurements were performed inside an urethral catheter in a gel phantom simulating a real prostate implant. Measured and expected doses were compared and the discrepancy was found to be within 8.9% and 3.8% for single MOSkin and dual-MOSkin configurations, respectively. Results show that dual-MOSkin detectors can be profitably adopted in prostate brachytherapy treatments to perform real-time in vivo dosimetry inside the urethra. - Highlights: • A needles implant was set-up in phantom to simulate prostate brachytherapy treatments. • In vivo dosimetry was performed in the urethral catheter with MOSkin dosimeters. • Dual-MOSkin detectors resulted to be accurate dosimeters to perform this task

  3. Contribution of new cytogenetic techniques in the estimations of old irradiations in retrospective biological dosimetry; Apport des nouvelles techniques de cytogenetiques dans l'estimation des irradiations anciennes en dosimetrie biologique retrospective

    Energy Technology Data Exchange (ETDEWEB)

    Pouzoulet, F

    2007-10-15

    The objective of this study was to answer three questions: if the translocations are steady: the results have shown that the translocations even if they are not obligatory steady can be used in retrospective dosimetry. Furthermore, it appeared important to consider the complex translocations in view of their relative stability and complementary information they bring ( quality of radiation, received dose). The second question is what contribution of the M-F.I.S.H. in the translocations analysis in comparison with the F.I.S.H.-3: we have shown that the M-F.I.S.H. would allow to raise the whole of doubt due to a partial genome observation. that has for effect to increase the precision of the analysis and that what ever be the received dose. The third question is if there are differences between the chromosomal aberrations generated by x radiation of 50 keV and by gamma radiation from cobalt-60: yes, the low energy photons generate more translocations than the photons coming from cobalt-60. But they generate less dicentrics. this difference comes from the way the energy is deposited that leads to a more important formation of complex and multiple translocations with the low energy photons. this could constitute a problem in the use of low energy photons in radiotherapy. it would seem that the simple translocations rate is not influenced by the photons energy. (N.C.)

  4. Dosimetry by ESR spectroscopy of alanine

    International Nuclear Information System (INIS)

    Dosimetry based on electron spin resonance analysis of radiation-induced free radicals in amino acids (e.g. L-alanine) is relevant to biological dosimetry applications. Typical features are a wide dose range covering more than 5 decades (1-105Gy), energy independent response for photons above 100 keV, long-term stability of the ESR signal, and fast straightforward readout technique. Typical dosimeter samples, consisting of small pellets of microcrystalline amino acids in paraffin, are rugged, non-toxic, and insensitive to surface contaminations. Moreover, they are prepared homogeneously and inexpensively in large batches and can be evaluated repeatedly and supply archival dosimetry data. They have proven to be highly useful in various applications of radiation processing and sterilization dosimetry, food irradiation, quality control, radiation dosimetry, radiation therapy measurements, and as a reference system for dosimetry mailing intercomparisons. (author)

  5. Clinical studies of optimised single crystal and polycrystalline diamonds for radiotherapy dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Descamps, C. [CEA-LIST (Recherche Technologique)/DETECS/SSTM/LCD, CEA/Saclay, Gif-sur-Yvette (France)], E-mail: cdescamps23@yahoo.fr; Tromson, D.; Tranchant, N. [CEA-LIST (Recherche Technologique)/DETECS/SSTM/LCD, CEA/Saclay, Gif-sur-Yvette (France); Isambert, A.; Bridier, A. [Institut Gustave Roussy, Villejuif (France); De Angelis, C.; Onori, S. [Dipartimento di Tecnologie e Salute, Istituto Superiore di Sanita, Roma (Italy); Bucciolini, M. [Dipartimento di Fisiopatologia dell' Universita, Firenze (Italy); Bergonzo, P. [CEA-LIST (Recherche Technologique)/DETECS/SSTM/LCD, CEA/Saclay, Gif-sur-Yvette (France)

    2008-02-15

    Natural diamond based ionisation chambers commercialised by PTW are used in several hospitals, and their dosimetric properties have been reported in many papers. Nevertheless their high costs and long delivery times are strong drawbacks. Advancements in the growth of synthetic diamonds offer new possibilities. This paper presents the dosimetric analysis in terms of stability and repeatability of the signal, background signal, detector response dynamics, linearity of the signal with the absorbed dose and dose rate dependence of synthetic optimised polycrystalline and single crystal diamonds. Both were elaborated at the CEA-LIST using the chemical vapour deposition (CVD) growth technique. The first dosimetric evaluation of single crystal diamond detector, reported here, shows a repeatability better than 0.1%, a good sensitivity around 70 nC/Gy compared to 3 nC/Gy for optimised polycrystalline diamond, very fast response with rise time around 1 s. Moreover, the signal linearity vs absorbed dose and energy dependence are very satisfactory. This preliminary dosimetric study with medical linear accelerators proves that diamond, and more precisely synthetic single crystal diamond, appears as a good alternative to air ionisation chambers for quality beam control and could be a good candidate for intensity modulated radiation therapy (IMRT) beams dosimetry.

  6. Thermoluminescence of kunzite: A study of kinetic processes and dosimetry characteristics

    Science.gov (United States)

    Ogundare, F. O.; Alatishe, M. A.; Chithambo, M. L.; Costin, G.

    2016-04-01

    Since the use of natural minerals for dating and dose reconstruction using luminescence techniques is well-established and always of interest, we present thermoluminescence characteristics of kunzite, a gem variety of spodumene. The chemical composition of the sample was determined using an Electron Probe MicroAnalyzer to be (Li0.996Na0.009Mn0.006)∑ = 1.016(Al0.981Cr0.003Fe2+0.001)∑ = 0.995[(Si1.993Al0.008)∑ = 2.000O6]. Thermoluminescence glow curves measured at 0.5 K/s after laboratory irradiation consist of three prominent peaks at 338 K (labelled as peak I), 454 K (peak II) and 681 K (peak III). The dose response of these three peaks is linear in the range 20-308 Gy studied. The position of each of the peaks is independent of dose, an archetypical feature of first order behaviour. However, detailed kinetic analyses showed that in fact, the peaks are not subject to first order kinetics. Each of the three peaks is affected by thermal quenching with an associated activation energy of thermal quenching estimated to be 0.70, 1.35 and 0.54 eV for peaks I, II and III respectively. In terms of dosimetry use, only peak III was found to be reliable for possible use in luminescence dating and dose reconstruction.

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

    International Nuclear Information System (INIS)

    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 CaF2 (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 CaSO4:Dy and CaSO4: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)

  8. Twelve years of neutron personnel dosimetry intercomparison studies at Oak Ridge National Laboratory: what have we learned?

    International Nuclear Information System (INIS)

    To provide an opportunity for dosimetrists to test and calibrate their personnel neutron monitoring systems in a variety of incident radiation fields, the staff of the Dosimetry Applications Research (DOSAR) Facility at the Oak Ridge National Laboratory (ORNL) has conducted personnel dosimetry intercomparison studies (PDIS) periodically since 1974 and annually since 1976 (Si82, Sw87). During these studies personnel dosimeters are mailed to ORNL, mounted on phantoms and exposed to low-level (less than 15 mSv) dose equivalents in mixed-radiation fields mainly produced using the Health Physics Research Reactor (HPRR) at ORNL (Au65), and then returned to the participants for evaluation. Reported dose equivalents are compared to reference values provided by the DOSAR staff and to results reported by individual organizations which made measurements under identical conditions. These intercomparisons, which require no fee and are open to any organization interested in external personnel dosimetry, have provided more data concerning neutron dosimeter performance characteristics in mixed-radiation fields than any other periodic open test program conducted to date. The following test presents a summary and analysis of neutron dose equivalent measurements reports for the Seventh through Twelfth inter-comparisons (1981-1986) using the HPRR as the source of radiation. Particular factors examined include low dose equivalent sensitivity and measurements accuracy for the basic types of neutron personnel dosimeters

  9. Biological dosimetry - a Bayesian approach in the presentation of the uncertainty of the estimated dose in cases of exposure to low dose radiation

    International Nuclear Information System (INIS)

    Biodosimetry laboratory experience has shown that there are limitations in the existing statistical methodology. Statistical difficulties generally occur due to the low number of aberrations leading to large uncertainties for dose estimation. Some problems derived from limitations of the classical statistical methodology, which requires that chromosome aberration yields be considered as something fixed and consequently provides a deterministic dose estimation and associated confidence limits. On the other hand, recipients of biological dosimetry reports, including medical doctors, regulators and the patients themselves may have a limited comprehension of statistics and of informed reports. Thus, the objective of the present paper is to use a Bayesian approach to present the uncertainty on the estimated dose to which a person could be exposed, in the case of low dose (occupational doses) radiation exposure. Such methodology will allow the biodosimetrists to adopt a probabilistic approach for the cytogenetic data analysis. At present, classical statistics allows to produce a confidence interval to report such dose, with a lower limit that could not detach from zero. In this situation it becomes difficult to make decisions as they could impact on the labor activities of the worker if an exposure exceeding the occupational dose limits is inferred. The proposed Bayesian approach is applied to occupational exposure scenario to contribute to take the appropriate radiation protection measures. (authors)

  10. Real-time optimized intraoperative dosimetry for prostate brachytherapy: A pilot study

    International Nuclear Information System (INIS)

    Purpose: To assess the feasibility of real-time intraoperative treatment planning for permanent prostate brachytherapy analyzing the impact on operative time and adequacy of postimplant dosimetry. Methods and Materials: Seventeen consecutive patients undergoing permanent brachytherapy for prostate cancer had real-time intraoperative computer-based and optimized treatment planning. The first 8 patients were implanted using a plan generated before the surgery and served to assure the team qualitatively that this could be performed without greatly increasing intraoperative time. They served as control group for expected achieved dosimetry results reviewing the D90, V100, V150 parameters from the dose-volume histograms. The next 9 patients were implanted according to the real-time plan. The times needed to carry out various steps of the procedure were recorded. The achieved dosimetry was then compared to the control group to assure that accuracy was unchanged. Results: The median operative time for patients undergoing intraoperative dosimetry was 57 min. Of this, 21 min were devoted to anesthesia and nursing functions. Postoperative dosimetry showed a median achieved V100 (volume of prostate receiving 100% of prescribed dose) of 97% for the control group. For the real-time dosimetry group, the median V100 was similar at 94%. The V150 (volume receiving 150%) is 49% for both groups. The D90 (dose received by 90% of the target) was normalized for easy comparison and was consistently slightly greater than the prescription dose. Conclusion: Treatment planning for permanent brachytherapy of prostate cancer has historically been performed as a computer-generated and optimized plan run weeks in advance of an implant, or according to a set pattern using an intraoperative nomogram. These data show that planning can now be optimized intraoperatively using widely available software without compromising the operative time or implant quality.

  11. Dosimetry Service

    CERN Multimedia

    2005-01-01

    The Dosimetry Service will be closed every afternoon the week of 21st to 25th February 2005. The opening hours will be from 8.30 am to 12.00 midday. Don't forget to read your dosimeter, as regular read-outs are indispensable to ensure periodic monitoring of personal doses. Thank you for you cooperation.

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

    International Nuclear Information System (INIS)

    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 CTDIvol is proportional to the dose to organ. In the case of the skull three-dimensional reconstruction tomography the CTDIvol was practically the same one that for simple tomography was practically; however, the doses to organs differed significantly. When comparing the TDIvol 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 CTDIvol 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)

  13. Potential of Hybrid Computational Phantoms for Retrospective Heart Dosimetry After Breast Radiation Therapy: A Feasibility Study

    Energy Technology Data Exchange (ETDEWEB)

    Moignier, Alexandra, E-mail: alexandra.moignier@irsn.fr [Institut de Radioprotection et de Surete Nucleaire, Fontenay-aux-Roses (France); Derreumaux, Sylvie; Broggio, David; Beurrier, Julien [Institut de Radioprotection et de Surete Nucleaire, Fontenay-aux-Roses (France); Chea, Michel; Boisserie, Gilbert [Groupe Hospitalier Pitie Salpetriere, Service de Radiotherapie, Paris (France); Franck, Didier; Aubert, Bernard [Institut de Radioprotection et de Surete Nucleaire, Fontenay-aux-Roses (France); Mazeron, Jean-Jacques [Groupe Hospitalier Pitie Salpetriere, Service de Radiotherapie, Paris (France)

    2013-02-01

    Purpose: Current retrospective cardiovascular dosimetry studies are based on a representative patient or simple mathematic phantoms. Here, a process of patient modeling was developed to personalize the anatomy of the thorax and to include a heart model with coronary arteries. Methods and Materials: The patient models were hybrid computational phantoms (HCPs) with an inserted detailed heart model. A computed tomography (CT) acquisition (pseudo-CT) was derived from HCP and imported into a treatment planning system where treatment conditions were reproduced. Six current patients were selected: 3 were modeled from their CT images (A patients) and the others were modelled from 2 orthogonal radiographs (B patients). The method performance and limitation were investigated by quantitative comparison between the initial CT and the pseudo-CT, namely, the morphology and the dose calculation were compared. For the B patients, a comparison with 2 kinds of representative patients was also conducted. Finally, dose assessment was focused on the whole coronary artery tree and the left anterior descending coronary. Results: When 3-dimensional anatomic information was available, the dose calculations performed on the initial CT and the pseudo-CT were in good agreement. For the B patients, comparison of doses derived from HCP and representative patients showed that the HCP doses were either better or equivalent. In the left breast radiation therapy context and for the studied cases, coronary mean doses were at least 5-fold higher than heart mean doses. Conclusions: For retrospective dose studies, it is suggested that HCP offers a better surrogate, in terms of dose accuracy, than representative patients. The use of a detailed heart model eliminates the problem of identifying the coronaries on the patient's CT.

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

    International Nuclear Information System (INIS)

    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)

  15. Study of some thermoluminescent phosphors for the dosimetry of ionizing radiations

    International Nuclear Information System (INIS)

    Thermoluminescence dosimetry techniques are reviewed and interactions radiation matter are recalled. The need for new phosphors is evidenced. Numerous phosphors are examined and calcium, strontium and barium sulfides are synthetized and deposited on glass supports. The thermoluminescence of the dosimeters obtained with these materials is analyzed

  16. A human head phantom for experimental dosimetry

    International Nuclear Information System (INIS)

    In order to achieve a better understanding of the behavior of nuclear particles in a human head experiment a phantom preserving similar tissues as well as similar anthropomorphic characteristics was used. In this work a biologic equivalent tissue material was developed, maintaining the chemical composition and tissue density, based on enriched PMMA. A humanoid head phantom was built using a human skull as a base, donated by the Morphology Department of the Institute for Biologic Sciences-ICB/UFMG. Muscles were replaced with biologic equivalent tissue material following anatomic precepts. The phantom presents: formalized animal salivary glands, brain and submandibular lymph nodes; human teeth; hair; prosthetic eyes and nose as well as human equivalent skin containing silicone and animal collagen. This phantom present several important conditions as human morphological characteristics, equivalent biological tissue and the head bone structure. It will be used in radiotherapy and brachytherapy studies, dosimetry and quality control of medical diagnostic image. (author)

  17. 1989 neutron and gamma personnel dosimetry intercomparison study using RADCAL [Radiation Calibration Laboratory] sources

    International Nuclear Information System (INIS)

    The fourteenth Personnel Dosimetry Intercomparison Study (i.e., PDIS 14) was conducted during May 1-5, 1989. A total of 48 organizations (33 from the US and 15 from abroad) participated in PDIS 14. Participants submitted by mail a total of 1,302 neutron and gamma dosimeters for this mixed field study. The type of neutron dosimeter and the percentage of participants submitting that type are as follows: TLD-albedo (40%), direct interaction TLD (22%), track (20%), film (7%), combination (7%), and bubble detectors (4%). The type of gamma dosimeter and the percentage of participants submitting that type are as follows: TLD (84%) and film (16%). Radiation sources used in the six PDIS 14 exposures included 252Cf moderated by 15-cm D2O, 252Cf moderated by 15-cm polyethylene (gamma-enhanced with 137Cs), and 238PuBe. Neutron dose equivalents ranged from 0.44--2.63 mSv and gamma doses ranged from 0. 01-1.85 mSv. One 252Cf(D2O) exposure was performed at a 60 degree angle of incidence (most performance tests are at perpendicular incidence). The average neutron dosimeter response for this exposure was 70% of that at normal incidence. The average gamma dosimeter response was 96% of that at normal incidence. A total of 70% of individual reported neutron dosimeter measurements were within ±50% of reference values. If the 0.01 mSv data are omitted, approximately 90% of the individual reported gamma measurements were within ±50% of reference values. 33 refs., 9 figs., 27 tabs

  18. Neutron personnel dosimetry

    International Nuclear Information System (INIS)

    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

  19. Study and parameters survey for iodine-125 source dosimetry to be applied in brachytherapy

    International Nuclear Information System (INIS)

    The use of brachytherapy technique with iodine-125 seeds to prostate cancer treatment has been used for decades with good clinical outcomes. To aim the Brazilian population necessities, IPEN-CNEN/SP developed the iodine-125 seed prototype with national technology. The objectives of this work are the development and the study of dosimetric procedures associates with the experimental acquisition of the useful parameters for the iodine-125 dosimetric characterization and to evaluate if the developed procedures, in this work, have the basic conditions to determinate the dosimetric analysis, that are fundamental for clinical procedures. The dosimeters selected for the analysis are the TLD-100 (LiF:Mg,Ti), initially these dosimeters were submitted for two selection steps to choose the dosimeters more reproducible for the dosimetric analysis. The two steps were the selection by the mass of the dosimeters and the reproducibility after four irradiation series in a Cobalt-60 irradiator (CTR-IPEN). Afterwards these steps, the dosimeters were irradiated in linear accelerator with 6 MV energy (Service of Radiotherapy - Hospital Israelita Albert Einstein) to yield the individual calibration factors to each dosimeter. After, the dosimeters were used to the irradiations with iodine-125 seed, 6711 model, (GE-Healthcare). The irradiations and others analysis with iodine-125 seeds yield the useful values for the determination of the parameters suggested by the AAPM (American Association of Physicists in Medicine): constant of dose rate, geometry function, dose radial function and anisotropy function. The results showed good agreement with the values published by the literature, for the same iodine- 125 model, this fact confirms that the realized parameters will be able to be used for the IPEN-CNEN iodine-125 seeds dosimetry and quality control. (author)

  20. Biological dosimetry to determine the UV radiation climate inside the MIR station and its role in vitamin D biosynthesis

    Science.gov (United States)

    Rettberg, P.; Horneck, G.; Zittermann, A.; Heer, M.

    1998-11-01

    The vitamin D synthesis in the human skin, is absolutely dependent on UVB radiation. Natural UVB from sunlight is normally absent in the closed environment of a space station like MIR. Therefore it was necessary to investigate the UV radiation climate inside the station resulting from different lamps as well as from occasional solar irradiation behind a UV-transparent quartz window. Biofilms, biologically weighting and integrating UV dosimeters successfully applied on Earth (e.g. in Antarctica) and in space (D-2, Biopan I) were used to determine the biological effectiveness of the UV radiation climate at different locations in the space station. Biofilms were also used to determine the personal UV dose of an individual cosmonaut. These UV data were correlated with the concentration of vitamin D in the cosmonaut's blood and the dietary vitamin D intake. The results showed that the UV radiation climate inside the Mir station is not sufficient for an adequate supply of vitamin D, which should therefore be secured either by vitamin D supplementat and/or by the regular exposure to special UV lamps like those in sun-beds. The use of natural solar UV radiation through the quartz window for `sunbathing' is dangerous and should be avoided even for short exposure periods.

  1. Photonic engineering for biological study

    Science.gov (United States)

    Wu, Fei

    My dissertation focuses on designing and developing prototypes of optical tools in the laboratory that can facilitate practical medical therapies. More specifically, this dissertation examines two novel biophotonic techniques: (1) a frequency multiplexed confocal microscope with the potential to provide rational therapy of congestive heart failure (CHF), and (2) the "optical comb" with the potential to improve results of retina reattachment surgery and accelerate post surgical recovery. Next, I will discuss the background, design and initial experimental results of each study individually. Part I: The Frequency Multiplexed Confocal Microscope. To overcome the limitations of existing confocal microscope technology, this dissertation proposes a non-scanning, real-time, high resolution technique (a multi-point frequency multiplexed confocal microscope) to measure 3-D intracellular calcium ion concentration in a living cardiac myocyte. This method can be also applied to measure the intracellular sodium ion concentration, or other ions in which high quantum-yield fluorescent probes are available. The novelty of the proposed research lies in the introduction of carrier frequency multiplexing techniques which can differentiate fluorescence emitted at different spatial locations in cardiac myocyte by their modulated frequency. It therefore opens the possibility to visualize the transient dynamics of intracellular dynamics at multiple locations in cells simultaneously, which will shine a new light on our understanding of CHF. The procedure for frequency multiplexing proposed is described below. Multiple incident laser beams are focused onto different locations in an isolated rat cardiac myocyte with each beam modulated at a different carrier frequency. The fluorescence emission at each location therefore bears the same modulated frequency as the stimulation laser beam. Each fluorescence signal is sent to the photo multiplier tube (PMT) after being spatially filtered by a

  2. Dosimetry Service

    CERN Multimedia

    Dosimetry Service

    2005-01-01

    Please remember to read your dosimeter every month at least once and preferably during the first week. A regular read-out is indispensable in order to ensure a periodic monitoring of the personal dose. You should read your dosimeter even if you have not visited the controlled areas. If you still have the old dosimeter (film badge), please send it immediately for evaluation to us (Bdg 24 E-011). After January 2005 there will be no developing process for the old film system. Information for Contractors: Please remember also to bring the form ‘Confirm Reception of a CERN Dosimeter' signed with ‘Feuille d'enregistrement du CERN'. Without these forms the dosimeter cannot be assigned. Thank you for your cooperation. Dosimetry Service Tel 767 2155 http://cern.ch/rp-dosimetry

  3. Hematological dosimetry

    International Nuclear Information System (INIS)

    The principles of hematological dosimetry after acute or protracted whole-body irradiation are reviewed. In both cases, over-exposure is never homogeneous and the clinical consequences, viz medullary aplasia, are directly associated with the mean absorbed dose and the seriousness and location of the overexposure. The main hematological data required to assess the seriousness of exposure are the following: repeated blood analysis, blood precursor cultures, as indicators of whole-body exposure; bone marrow puncture, medullary precursor cultures and medullary scintigraphy as indicators of the importance of a local over-exposure and capacity for spontaneous repair. These paraclinical investigations, which are essential for diagnosis and dosimetry, are also used for surveillance and for the main therapeutic issues

  4. Dosimetry Service

    CERN Multimedia

    2004-01-01

    We wish to remind the people who are invited to the Dosimetry Service to exchange the new CERN dosimeter that the hours are from Monday to Friday 8.30 to 11.00 and 14.00 to 16.00. Do not forget to read your dosimeter. The reading should be done during the first week of every month. Thank you for your cooperation.

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

    International Nuclear Information System (INIS)

    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)

  6. Amylase and blood cell-count hematological radiation-injury biomarkers in a rhesus monkey radiation model-use of multiparameter and integrated biological dosimetry

    International Nuclear Information System (INIS)

    Effective medical management of suspected radiation exposure incidents requires the recording of dynamic medical data (clinical signs and symptoms), biological assessments of radiation exposure, and physical dosimetry in order to provide diagnostic information to the treating physician and dose assessment for personnel radiation protection records. The need to rapidly assess radiation dose in mass-casualty and population-monitoring scenarios prompted an evaluation of suitable biomarkers that can provide early diagnostic information after exposure. We investigated the utility of serum amylase and hematological blood-cell count biomarkers to provide early assessment of severe radiation exposures in a non-human primate model (i.e., rhesus macaques; n=8) exposed to whole-body radiation of 60Co-gamma rays (6.5 Gy, 40cGymin-1). Serum amylase activity was significantly elevated (12.3±3.27- and 2.6±0.058-fold of day zero samples) at 1 and 2-days, respectively, after radiation. Lymphocyte cell counts decreased (≤15% of day zero samples) 1 and 2 days after radiation exposure. Neutrophil cell counts increased at day one by 1.9(±0.38)-fold compared with levels before irradiation. The ratios of neutrophil to lymphocyte cell counts increased by 13(±2.66)- and 4.23(±0.95)-fold at 1 and 2 days, respectively, after irradiation. These results demonstrate that increases in serum amylase activity along with decreases of lymphocyte counts, increases in neutrophil cell counts, and increases in the ratio of neutrophil to lymphocyte counts 1 day after irradiation can provide enhanced early triage discrimination of individuals with severe radiation exposure and injury. Use of the biodosimetry assessment tool (BAT) application is encouraged to permit dynamic recording of medical data in the management of a suspected radiological casualty

  7. 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” dose recovery experiments. The minimum detection limit (MDL) dose was about 0.1Gy. The dose dependence was measured using both the above SAR OSL protocol as well as a SAR thermoluminescence (TL, violet emission) protocol. The background doses were generally in the range of the MDL to several Gy......, and no clear trend in dose depth profile was observed. From these results, we conclude that SAR OSL dosimetry using natural quartz extracted from soil could be used to evaluate the dose of an accident....

  8. Analysis of patient specific dosimetry quality assurance measurements in intensity modulated radiotherapy: A multi centre study

    Directory of Open Access Journals (Sweden)

    Rajesh Kumar

    2014-01-01

    Conclusion: IMRT centers are having random and biased (skewed towards over or under dose distribution of the percentage variation in difference between measured and planned doses. The analysis of results of the IMRT pre-treatment dose verification reveals that there are systematic errors in the chain of IMRT treatment process at a few centers. The dosimetry quality audit prior to commissioning of IMRT may play an important role in avoiding such discrepancies.

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

    OpenAIRE

    Zhumadilov, Kassym; Ivannikov, Alexander; Stepanenko, Valeriy; Zharlyganova, Dinara; Zhumadilov, Zhaxybay; Apsalikov, Kazbek; Toyoda, Shin; Zhumadilova, Anara; Endo, Satoru; Tanaka, Kenichi; Miyazawa, Chuzou; Yamamoto, Masayoshi; Okamoto, Tetsuji; Hoshi, Masaharu

    2012-01-01

    The method of electron spin resonance (ESR) dosimetry was used to human tooth enamel to obtain individual absorbed doses of population of settlements in the vicinity of the Semipalatinsk Nuclear Test Site (SNTS), Kazakhstan. The distances between investigated settlements and Ground Zero (SNTS) are in the range 70 - 200 km from SNTS. Most of settlements (Dolon, Mostik, Bodene) are located near the central axis of radioactive fallout trace from the most contaminating surface nuclear test, which...

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

    International Nuclear Information System (INIS)

    We investigated the whole-body biodistributions and radiation dosimetry of five 11C-labeled and one 18F-labeled radiotracers in human subjects, and compared the results to those obtained from murine biodistribution studies. The radiotracers investigated were 11C-SA4503, 11C-MPDX, 11C-TMSX, 11C-CHIBA-1001, 11C-4DST, and 18F-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. Pharmacokinetic, Dosimetry and Toxicity Study of ¹⁷⁷Lu-EDTMP in Patients: Phase 0/I study.

    Science.gov (United States)

    Bal, Chandrasekhar; Arora, Geetanjali; Kumar, Praveen; Damle, Nishikant; Das, Tapas; Chakraborty, Sudipta; Banerjee, Sharmila; Venkatesh, Meera; Zaknun, John J; Pillai, M R A

    2016-01-01

    177Lu-EDTMP has been proposed as a potent bone pain palliation agent owing to theoretical advantage of reduced bone marrow suppression resulting from the low β(-) energy and a suitably long half-life facilitating its wider distribution with less loss from radioactive decay. Herein, we report the pharmacokinetics, dosimetry and toxicity analysis of 177Lu-EDTMP in patients (phase-0/I study). In a phase-0 study, the biokinetics of skeletal and non-skeletal uptake of 177Lu-EDTMP was assessed in 6 patients with metastatic prostate cancer using tracer doses (172.7-206.9MBq). Data of whole skeletal uptake, blood and fractionated urine samples were obtained and dosimetric calculations were performed using the OLINDA/EXM 1.0 software. Prolonged bone retention was observed in all patients. Excretion was mainly via the renal route and blood clearance was rapid and biphasic. Mean estimated red marrow dose was 0.80±0.15mGy/MBq while mean total-body dose was 0.16±0.04mGy/MBq. A maximum tolerated dose (MTD) of 2000-3250MBqfor 177Lu-EDTMP was calculated. For the phase-I study, 21 patients with metastatic prostate cancer were given a therapeutic dose of 177Lu- EDTMP (692-5550MBq). Toxiciy (WHO), evaluated by assessment of hemoglobin levels, platelet and leukocyte counts over 12 weeks, was mainly limited to anemia or thrombocytopenia. Only transient toxicity was observed in 14/21 patients, of which 6 had baseline toxicity. Beyond the MTD, a significantly higher number of patients displayed grade 3-4 toxicity. Pain relief, assessed by VAS pain score, was observed in 86% patients with median relief duration of 7 weeks. The results demonstrate that 177Lu-EDTMP has excellent pharmacokinetic and dosimetric properties, besides being safe and effective. Along with estimating radiation dose values to certain critical organs, we have also proposed an MTD for 177Lu-EDTMP that correlated well with toxicity data. The encouraging dosimetry and toxicity data of 177Lu-EDTMP reported provide the

  12. Radioembolization Dosimetry: The Road Ahead

    Energy Technology Data Exchange (ETDEWEB)

    Smits, Maarten L. J., E-mail: m.l.j.smits-3@umcutrecht.nl; Elschot, Mattijs [University Medical Center Utrecht, Department of Radiology and Nuclear Medicine (Netherlands); Sze, Daniel Y. [Stanford University School of Medicine, Division of Interventional Radiology (United States); Kao, Yung H. [Austin Hospital, Department of Nuclear Medicine (Australia); Nijsen, Johannes F. W. [University Medical Center Utrecht, Department of Radiology and Nuclear Medicine (Netherlands); Iagaru, Andre H. [Stanford University School of Medicine, Division of Nuclear Medicine and Molecular Imaging (United States); Jong, Hugo W. A. M. de; Bosch, Maurice A. A. J. van den; Lam, Marnix G. E. H. [University Medical Center Utrecht, Department of Radiology and Nuclear Medicine (Netherlands)

    2015-04-15

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

  13. Studies on Semantic Systems Chemical Biology

    Science.gov (United States)

    Chen, Bin

    2012-01-01

    Current "one disease, one target and one drug" drug development paradigm is under question as relatively few drugs have reached the market in the last two decades. Increasingly research focus is being placed on the study of drug action against biological systems as a whole rather than against a single component (called "Systems…

  14. Recent developments in the dosimetry of superficial tissues

    International Nuclear Information System (INIS)

    The biological basis of current dosimetry techniques for superficial tissues is presented and the areas of biological uncertainty which need to be clarified are identified. Examples are provided of practical situations in which potential skin exposure is of concern and recent developments of dosimetry techniques for superficial exposures are reviewed with particular reference to Beta particles and low energy x-rays. (author)

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

    International Nuclear Information System (INIS)

    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

  16. II. Biological studies of radiation effects

    Energy Technology Data Exchange (ETDEWEB)

    Lawrence, J.H.

    1948-05-24

    With the completion of the 184 inch cyclotron in Berkeley and the successful construction of a deflector system, it was possible to bring the 190 Mev deuteron and the 380 Mev alpha beams out into the air and to begin a study of the effects of high-energy deuteron beams by direct irradiation of biological specimens. The direct biological use of deuteron beams was attempted earlier in Berkeley by Marshak, MacLeish, and Walker in 1940. These and other investigators have been aware for some time of the potential usefulness of high energy particle beams for radio-biological studies and their suitability for biological investigations. R.R. Wilson advanced the idea of using fast proton beams to deliver radiation and intervening tissues. R.E. Zirkle pointed out that such particle beams may be focused or screened until a cross-section of the beam is small enough to study effects of irradiation under the microscope on single cells or on parts of single cells. This article gives an overview of the radiological use of high energy deuteron beams, including the following topics: potential uses of high energy particle beams; experiments on the physical properties of the beam; lethal effect of the deuteron beam on mice.

  17. Biological dosimetry of low doses (0.05 - 0.4 Gy) with micronucleus dicentrics and chromosome fragments

    International Nuclear Information System (INIS)

    This study was carried out within the framework of the agreement between the National Nuclear Safety Council and the University of Alcala of Hernares and in co-operation with the Radiological Service and the Radiation Protection Unit of the Gregorio Maranon General Hospital of Madrid, where irradiations were performed. Blood samples were taken of 4 individuals irradiated with 6 doses of gamma rays between 0.05 Gy and 0.40 Gy, leaving an aliquot dose of 0 Gy. Cultures of lymphocytes for the study of dicentric chromosomes (DC) and chromosomal fragments (fr), stopping the first mitosis after postirradiation with Colcemid. A study of micronuclei (MN) in binuclear cells was also performed, interrupting the first cytokinesis after postirradiation with citocalasina B. After the corresponding studies with optical microscope, statistical analysis was made on the observed data on DC, fr and MN. We made a multiple linear regression analysis of the data of the 4 individuals. We obtained the average of the 4 individuals for each variable and dose and performed the variance analysis. According to our study, neither the DC nor the MN are valid dosemeters for lower doses up to 0.4 Gy. Nevertheless there are indications that the fragments are correlated with the dose to these levels. By increasing both the points of dose and the number of metaphases studied, we believe that a dose curve can be done that would allow to estimate with a reasonable degree of confidence the dose received by a sample irradiated

  18. SU-E-T-120: Dosimetric Characteristics Study of NanoDotâ,,¢ for In-Vivo Dosimetry

    International Nuclear Information System (INIS)

    Purpose: The purpose of the study was to analyze the dosimetric characteristics (energy dependence, reproducibility and dose linearity) of nanoDot™ optically stimulated luminescence dosimeters (OSLDs) and validate their potential use during in-vivo dosimetry, specifically TBI. The manufacturer stated accuracy is ±10% for standard nanoDot™. Methods: At AKUH, the InLight microStar OSL dosimetry system for patient in-vivo dosimetry is in use since 2012. Twenty-five standard nanoDot™ were used in the analysis. Sensitivity and reproducibility was tested in the first part with 6MV and 18 MV Varian x-ray beams. Each OSLD was irradiated to 100cGy dose at nominal SSD (100 cm). All the OSLDs were read 3 times for average reading. Dose linearity and calibration were also performed with same beams in common clinical dose range of 0 - 500 cGy. In addition, verification of TBI absolute dose at extended SSD (500cm) was also performed. Results: The reproducibility observed with the OSLD was better than the manufacturer stated limits. Measured doses vary less than ±2% in 19(76%) OSLDs, whereas less than ±3% in 6(24%) OSLDs. Their sensitivity was approximately 525 counts per cGy. Better agreement was observed between measurements, with a standard deviation of 1.8%. A linear dose response was observed with OSLDs for both 6 and 18MV beams in 0 - 500 cGy dose range. TBI measured doses at 500 cm SSD were also confirmed to be within ±0.5% and ±1.3% of the ion chamber measured doses for 6 and 18MV beams respectively. Conclusion: The dosimetric results demonstrate that nanoDot™ can be potentially used for in-vivo dosimetry verification in various clinical situations, with a high degree of accuracy and precision. In addition OSLDs exhibit better dose reproducibility with standard deviation of 1.8%. There was no significant difference in their response to 6 and 18MV beams. The dose response was also linear

  19. Internal dosimetry, past and future

    International Nuclear Information System (INIS)

    This paper is a review of the progress in the dosimetry of internally deposited radionuclides (internal dosimetry) since World War II. Previous to that, only naturally occurring radionuclides were available and only a limited number of studies of biokinetics and dosimetry were done. The main radionuclides studied were 226Ra, 228Ra, and 224Ra but natural uranium was also studied mainly because of its toxic effect as a heavy metal, and not because it was radioactive. The effects of 226Ra in bone, mainly from the radium dial painters, also formed the only bases for the radiotoxicity of radionuclides in bone for many years, and it is still, along with 224Ra, the main source of information on the effects of alpha emitters in bone. The publications of the International Commission on Radiological Protection that have an impact on internal dosimetry are used as mileposts for this review. These series of publications, more than any other, represent a broad consensus of opinion within the radiation protection community at the time of their publication, and have formed the bases for radiation protection practice throughout the world. This review is not meant to be exhaustive; it is meant to be a personnel view of the evolution of internal dosimetry, and to present the author's opinion of what the future directions in internal dosimetry will be. 39 refs., 2 tabs

  20. 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

  1. NMR Studies on Organic and Biological Solids

    OpenAIRE

    Yang, Chen

    2015-01-01

    Solid-state NMR (SSNMR) studies on biomolecules and organic molecular crystals are presented here. The biological part of the work is focused on improving resolution and sensitivity of SSNMR techniques for larger protein systems, while the studies on organic molecular crystals extend the application of SSNMR to determining the crystal structure of a photoreaction intermediate. First, a long-observation-window band-selective homonuclear decoupling scheme is introduced. The homonuclear decoupli...

  2. Neutron beam measurement dosimetry

    International Nuclear Information System (INIS)

    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

  3. Neutron beam measurement dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Amaro, C.R. [Idaho National Engineering Lab., Idaho Falls, ID (United States)

    1995-11-01

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

  4. Study of the positioning of the films of the MLC by a Test of bands and your influence in the clinic dosimetry in IMRT

    International Nuclear Information System (INIS)

    We performed a test of adjacent bands inspired by the proposed in AAPM Report No. 72, we provides a parameter characterizing the state of the MLC as to the actual position of its blades. This test has been validated by studying repeatability and reproducibility and has found the correlation between the parameter and creep detected by the ILD. Subsequently it has studied the impact of changes in the positioning of the blades on clinical dosimetry in IMRT patients, reconstructing the patient dose by Matrix Evolution team and Compass software, IBA Dosimetry. (Author)

  5. Progress report, Biology and Health Physics Division, April 1 to June 30, 1975

    International Nuclear Information System (INIS)

    Interim results are reported on research at CRNL in health physics (dosimetry, instrumentation, monitoring); environmental research (limnology, radionuclide migration and kinetics); populaton research (tumor induction in mammals, human health records); and biology (radiobiology, genetic studies). (E.C.B.)

  6. Study of the secondary neutral radiation in proton therapy: Toward an indirect in vivo dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Carnicer, A.; Letellier, V.; Rucka, G.; Angellier, G.; Sauerwein, W.; Herault, J. [Centre Antoine Lacassagne, Cyclotron Biomedical, 227 Avenue de la Lanterne, 06200 Nice (France); Institut Curie, Centre de Protontherapie, Campus Universitaire d' Orsay, Batiment 101, 91898 Orsay Cedex (France); Hopital de la Croix Rouge, Centre de radiotherapie St Louis, Rue Andre Blondel, 83100 Toulon (France); Centre Antoine Lacassagne, Cyclotron Biomedical, 227 Avenue de la Lanterne, 06200 Nice (France); Universitaet Duisburg-Essen, Universitaetsklinikum Essen, Strahlenklinik, 45122 Essen (Germany); Centre Antoine Lacassagne, Cyclotron Biomedical, 227 Avenue de la Lanterne, 06200 Nice (France)

    2012-12-15

    between calculations and measurements were 2.3 and 0.5 for neutrons and photons, respectively, and remained constant for all the range of SOBPs studied, which provided validation for the Monte Carlo calculations. H*(10)/D values were found to correlate to the proton dose rate D/MU with a power fit, both for neutrons and photons. This result was exploited to implement a system to obtain D/MU values from the measurement of the integrated photon ambient dose equivalent H*(10) during treatment, which provides a method to control the dosimetric parameters D/MU and D. Conclusions: The treatment room at CAL is moderately polluted by secondary particles. The constant ratio between measurements and calculations for all SOBPs showed that simulations correctly predict the dosimetric parameters and the dependence of the production of secondary particles on the modulation. The correlation between H*(10)/D and D/MU is a useful tool for quality control and is currently used at CAL. This system works as an indirect in vivo dosimetry method, which is so far not feasible in proton therapy. This tool requires very simple instrumentation and can be implemented from the measurement of either photons or neutrons.

  7. Study of the response of phenol compounds exposed to thermal neutrons beams for Electron Paramagnetic Resonance dosimetry

    International Nuclear Information System (INIS)

    This paper reports the results regarding a new organic compound (IRGANOX® 1076 phenols) with and without low content (5% by weight) of gadolinium oxide (Gd2O3) for Electron Paramagnetic Resonance (EPR) dosimetry of neutron beams. The dependence of EPR signal as function of neutron dose was investigated in the fluence range studied between 1011 cm−2 to 1014 cm−2. We evaluated also the effect of gadolinium on 60Co gamma photon sensitivity of this organic compound. Our analysis showed that a low concentration of gadolinium oxide (of the order of 5% of the total mass of the dosimeter) can enhance the thermal neutron sensitivity more than 10 times with a small reduction of photon tissue equivalence. The free radicals produced after irradiation of photons and neutrons are stable for more than first 300 h after irradiation. The presence of additives does not substantially modify the fading of the EPR signal induced by photons and neutrons in the first 15 days after exposure. - Highlights: • Linearity of the EPR response of phenol compound with gadolinium exposed to photons. • Linearity of the EPR response of phenol compound with and without gadolinium exposed to neutrons. • Stability of the signal in the first 300 h after irradiations. • Possibility of using this material for EPR dosimetry

  8. Joint USNRC/EC consequence uncertainty study: The ingestion pathway, dosimetry and health effects expert judgment elicitations and results

    Energy Technology Data Exchange (ETDEWEB)

    Harper, F. [Sandia National Labs., Albuquerque, NM (United States); Goossens, L. [Delft Univ. of Technology (Netherlands); Abbott, M. [Lockheed Idaho Technologies Co., Idaho Falls, ID (United States)] [and others

    1996-08-01

    The US Nuclear Regulatory Commission (USNRC) and the European Commission (EC) have conducted a formal expert judgment elicitation jointly to systematically collect the quantitative information needed to perform consequence uncertainty analyses on a broad set of commercial nuclear power plants. Information from three sets of joint US/European expert panels was collected and processed. Information from the three sets of panels was collected in the following areas: in the phenomenological areas of atmospheric dispersion and deposition, in the areas of ingestion pathways and external dosimetry, and in the areas of health effects and internal dosimetry. This exercise has demonstrated that the uncertainty for particular issues as measured by the ratio of the 95th percentile to the 5th percentile can be extremely large (orders of magnitude), or rather small (factor of two). This information has already been used by many of the experts that were involved in this process in areas other than the consequence uncertainty field. The benefit to the field of radiological consequences is just beginning as the results of this study are published and made available to the consequence community.

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

    International Nuclear Information System (INIS)

    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)

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

    Energy Technology Data Exchange (ETDEWEB)

    Fujita, H. [Japan Atomic Energy Agency, Ibaraki (Japan). Nuclear Fuel Cycle Engineering Labs.; Risoe National Laboratory for Sustainable Energy, Technical Univ. of Denmark, Roskilde (Denmark). Radiation Research Div.; Jain, M. [Risoe National Laboratory for Sustainable Energy, Technical Univ. of Denmark, Roskilde (Denmark). Radiation Research Div.; Murray, A.S. [Aarhus Univ., Risoe DTU, Roskilde (Denmark). Nordic Lab. for Luminescence Dating

    2011-07-01

    The optimum conditions of preheat temperature, stimulation temperature, etc. in the single-aliquot regenerative optically stimulated luminescence (SAR OSL) method were examined specifically for measuring background dose in natural quartz extracted from soils collected around Tokai-mura in Japan. 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'' dose recovery experiments. The minimum detection limit (MDL) dose was about 0.1 Gy. The dose dependence was measured using both the above SAR OSL protocol as well as a SAR thermoluminescence (TL, violet emission) protocol. The background doses were generally in the range of the MDL to several Gy, and no clear trend in dose depth profile was observed. From these results, we conclude that SAR OSL dosimetry using natural quartz extracted from soil could be used to evaluate the dose of an accident. (orig.)

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

    International Nuclear Information System (INIS)

    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)

  12. Preliminary study of MAGAT polymer gel dosimetry for boron-neutron capture therapy

    International Nuclear Information System (INIS)

    MAGAT gel dosimeter with boron is irradiated in Heavy Water Neutron Irradiation Facility (HWNIF) of Kyoto University Research Reactor (KUR). The cylindrical gel phantoms are exposed to neutron beams of three different energy spectra (thermal neutron rich, epithermal and fast neutron rich and the mixed modes) in air. Preliminary results corresponding to depth-dose responses are obtained as the transverse relaxation rate (R2=1/T2) from magnetic resonance imaging data. As the results MAGAT gel dosimeter has the higher sensitivity on thermal neutron than on epi-thermal and fast neutron, and the gel with boron showed an enhancement and a change in the depth-R2 response explicitly. From these results, it is suggested that MAGAT gel dosimeter can be an effective tool in BNCT dosimetry

  13. Preliminary study of MAGAT polymer gel dosimetry for boron-neutron capture therapy

    Science.gov (United States)

    Hayashi, Shin-ichiro; Sakurai, Yoshinori; Uchida, Ryohei; Suzuki, Minoru; Usui, Shuji; Tominaga, Takahiro

    2015-01-01

    MAGAT gel dosimeter with boron is irradiated in Heavy Water Neutron Irradiation Facility (HWNIF) of Kyoto University Research Reactor (KUR). The cylindrical gel phantoms are exposed to neutron beams of three different energy spectra (thermal neutron rich, epithermal and fast neutron rich and the mixed modes) in air. Preliminary results corresponding to depth-dose responses are obtained as the transverse relaxation rate (R2=1/T2) from magnetic resonance imaging data. As the results MAGAT gel dosimeter has the higher sensitivity on thermal neutron than on epi-thermal and fast neutron, and the gel with boron showed an enhancement and a change in the depth-R2 response explicitly. From these results, it is suggested that MAGAT gel dosimeter can be an effective tool in BNCT dosimetry.

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

    Energy Technology Data Exchange (ETDEWEB)

    Liz, Otavio S.R.; Medeiros, Adriana S. [Universidade Federal de Minas Gerais (DEN/UFMG), Belo Horizonte, MG (Brazil). Dept. de Engenharia Nuclear; Faria, Luiz O., E-mail: farialo@cdtn.b [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2011-07-01

    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{sup -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{sup -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)

  15. A study on the radiation and environment safety -Development of technology for biological dosimetry-

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Kang Suk; Kim, Kook Chan; Kim, In Kyoo; Kim, Jin Kyoo; Chun Kee Jung; Park, Hyo Kook; Kim, Sang Bok; Park Sun Yung [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1995-07-01

    Adult rats were treated a single, whole body exposure to a dose of 0.1, 0.5, 1.0, 2.0, 3.0 Gy. The animals were sacrificed 6, 24, 48, 72, 96 hours following exposure. The amount of serum acute phase proteins(haptoglobin, ceruloplasmin, C-reactive protein, alpha-1 antitrypsin, alpha-1 acid glycoprotein, transferrin) were measured by competitive ELISA. In the 0.1 Gy irradiated rats, serum haptoglobin, C-reactive protein and alpha-1 antitrypsin were 400% higher and serum transferrin was 50% lower as compared to controls, 96 hours after irradiation. Ceruloplasmin increased by 400%, 24 hours after irradiation, but 96 hours after irradiation, the concentration of this protein in rat returned to normal level. On the other hand, no changes were observed in the case of alpha-1 acid glycoprotein. In the group of the 3.0 Gy irradiated rats, transferrin increased by 200%, 96 hours after irradiation. These biochemical responses to radiation did not show dose-dependent relation, but the sensitivity of the indicators was high enough to detect absorbed dose of 0.1 Gy. The above results can be applied to the measurements of acute phase reactants in human serum for the assessment of exposure doses in radiation workers and patients under radiation therapy. 39 figs, 72 refs. (Author).

  16. Personnel neutron dosimetry at Department of Energy facilities

    Energy Technology Data Exchange (ETDEWEB)

    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.

  17. Personnel neutron dosimetry at Department of Energy facilities

    International Nuclear Information System (INIS)

    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

  18. Feasibility study on the verification of actual beam delivery in a treatment room using EPID transit dosimetry

    International Nuclear Information System (INIS)

    The aim of this study is to evaluate the ability of transit dosimetry using commercial treatment planning system (TPS) and an electronic portal imaging device (EPID) with simple calibration method to verify the beam delivery based on detection of large errors in treatment room. Twenty four fields of intensity modulated radiotherapy (IMRT) plans were selected from four lung cancer patients and used in the irradiation of an anthropomorphic phantom. The proposed method was evaluated by comparing the calculated dose map from TPS and EPID measurement on the same plane using a gamma index method with a 3% dose and 3 mm distance-to-dose agreement tolerance limit. In a simulation using a homogeneous plastic water phantom, performed to verify the effectiveness of the proposed method, the average passing rate of the transit dose based on gamma index was high enough, averaging 94.2% when there was no error during beam delivery. The passing rate of the transit dose for 24 IMRT fields was lower with the anthropomorphic phantom, averaging 86.8% ± 3.8%, a reduction partially due to the inaccuracy of TPS calculations for inhomogeneity. Compared with the TPS, the absolute value of the transit dose at the beam center differed by −0.38% ± 2.1%. The simulation study indicated that the passing rate of the gamma index was significantly reduced, to less than 40%, when a wrong field was erroneously irradiated to patient in the treatment room. This feasibility study suggested that transit dosimetry based on the calculation with commercial TPS and EPID measurement with simple calibration can provide information about large errors for treatment beam delivery

  19. Long term stability studies of the Harshaw Tld 6600 system used for personal dosimetry monitoring in Ghana

    International Nuclear Information System (INIS)

    A dosimetry system made up of the Harshaw TLD 6600 has been used in the monitoring of occupationally exposed workers and for research purposes in Ghana since 1998. Continuous use, calibration and maintenance have been done periodically on the equipment at the Personal Monitoring Service (PMS) laboratory since its installation at the PMS laboratory of the Radiation Protection Institute in Ghana. The Daily Electronics Quality Control (DEQC) test carried out to ensure that the Harshaw 6600 TLD Reader was in good working condition prior to the reading of TLD cards. The present work was done to assess the long term stability of the system with respect to the DEQC parameter in order to ensure quality control and accurate measurements for personal dosimetry in Ghana. The parameters under investigation included the high voltage, temperature, reference light, plus and minus 15 volts, ground, digital to analog conversion and the photomultiplier tube noise. WINREMS software is incorporated into a computer to monitor these parameters in order to verify whether they conform to performance standards. The annual mean reference light values in nano coulomb for chip (ii) were 471.0±49.5, 77.0±109.2, 18.5±7.9, 31.0±81.1 and 18.7±3.2; for chip (iii) were 475.1±45.7, 102.4±132.8, 74.3±107.4, 83.7±125.3 and 8.6±3.1 respectively. These values are outside the reference ranges indicating instability for the period of five (5) years (2008 to 2012). Measurement of exposed TLDs to known doses at the SSDL confirmed the PMT gain stability of system. The instability in the reference light readings was due to ageing and yellowing of the optical portion of the reference light. The high voltage and the reference light were unstable. The temperature, plus and minus 15 volts, ground and digital to analog conversion and PMT noise were all stable. The study indicates the PMS therefore provides a reliable and accurate dosimetry in the long term. (au)

  20. Studying dosimetric parameters of thermoluminescent dosemeter of CaSO4:Dy powder made in the Nuclear Research Institute for personal radiation dosimetry

    International Nuclear Information System (INIS)

    The research group of the Nuclear Research Institute (NRI) itself studied and successfully made thermoluminescent dosemeters (TLDs) using powder material of CaSO4:Dy in 2014. For external personal dosimetry, dosimetric parameters of the TLDs were surveyed by radiating with various gamma doses of 137Cs source and measured by Rexon-320 Reader such as glow curve with temperature, calibration factor (or response value), homogeneity of the batch, reproducibility of measurement, linearity of dose response, limit of detection, fading, light sensitivity, dose-rate dependence, and energy dependence of the response, etc. The studied results were shown that the dosemeters were ensured for personal dosimetry according to the standards of IEC-61066:2006. Besides, the TLDs were also radiated with standard doses of gamma (137Cs) and X-rays at the Secondary Standards Dosimetry Laboratory (SSDL) of the Institute for Nuclear Science and Technology in Hanoi. Comparison results on dose were shown that the TLDs have been confident. Therefore, they have been used for routinely external personal dosimetry for radiation workers in the NRI and other radiation installations from the beginning of 2015. (author)

  1. 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...

  2. Heavy construction equipment noise study using dosimetry and time-motion studies

    Science.gov (United States)

    Spencer, Ellsworth R.; Yantek, David S.

    2005-09-01

    Noise-induced hearing loss continues to afflict workers in many occupational settings despite longstanding recognition of the problems and well-known methods of prevention and regulations. Sound levels associated with heavy construction equipment range from 80 to 120 dB(A) and power tools commonly used in construction produce sound levels up to 115 dB(A). The focus of the research was to determine the noise exposures of heavy construction equipment operators while documenting the workers' tasks, (i.e., hauling, moving, and/or pushing construction material). Time-motion studies were performed at the construction sites and were used to correlate the noise dosage with the work performed by equipment operators. The cumulative dose for the operator was then plotted with references to work tasks, to identify the tasks that caused the greatest noise exposure. Three construction sites were examined and located in the western Pennsylvania and eastern Ohio areas. The types of construction equipment studied included asphalt pavers, backhoes, bulldozers, compaction equipment, excavators, haul trucks, telehandlers, and wheeled loaders. The results showed that bulldozer operators consistently had the highest noise exposures, ranging from a NIOSH REL (Recommended Exposure Limit) dose of 844% to 25836% and an OSHA PEL (Permissible Exposure Limit) dose of 139% to 1397%.

  3. Breast dosimetry

    International Nuclear Information System (INIS)

    The estimation of the absorbed dose to the breast is an important part of the quality control of the mammographic examination. Knowledge of breast dose is essential for the design and performance assessment of mammographic imaging systems. This review gives a historical introduction to the measurement of breast dose. The mean glandular dose (MGD) is introduced as an appropriate measure of breast dose. MGD can be estimated from measurements of the incident air kerma at the surface of the breast and the application of an appropriate conversion factor. Methods of calculating and measuring this conversion factor are described and the results discussed. The incident air kerma itself may be measured for patients or for a test phantom simulating the breast. In each case the dose may be determined using TLD measurements, or known exposure parameters and measurements of tube output. The methodology appropriate to each case is considered and the results from sample surveys of breast dose are presented. Finally the various national protocols for breast dosimetry are compared

  4. Absorbed dose in molecular radiotherapy: a comparison study of Monte Carlo, dose voxel kernels and phantom based dosimetry

    International Nuclear Information System (INIS)

    Full text of publication follows. Aim: the aim of this study was to perform a critical comparison of 3 dosimetric approaches in Molecular Radiotherapy: phantom based dosimetry, Dose Voxel Kernels (DVKs) and full Monte Carlo (MC) dosimetry. The objective was to establish the impact of the absorbed dose calculation algorithm on the final result. Materials and Methods: we calculated the absorbed dose to various organs in six healthy volunteers injected with a novel 18F-labelled PET radiotracer from GE Healthcare. Each patient underwent from 8 to 10 whole body 3D PET/CT scans. The first 8 scans were acquired dynamically in order to limit co-registration issues. Eleven organs were segmented on the first PET/CT scan by a physician. We analysed this dataset using the OLINDA/EXM software taking into account actual patient's organ masses; the commercial software Stratos by Philips implementing a DVK approach; and performing full MC dosimetry on the basis of a custom application developed with Gate. The calculations performed with these three techniques were based on the cumulated activities calculated at the voxel level by Stratos. Results: all the absorbed doses calculated with Gate were higher than those calculated with OLINDA. The average ratios between the Gate absorbed dose and OLINDA's was 1.38±0.34 σ (from 0.93 to 2.23) considering all patients. The discrepancy was particularly high for the thyroid, with an average Gate/OLINDA ratio of 1.97±0.83 σ for the 6 patients. The lower absorbed doses in OLINDA may be explained considering the inter-organ distances in the MIRD phantom. These are in general overestimated, leading to lower absorbed doses in target organs. The differences between Stratos and Gate resulted to be the highest. The average ratios between Gate and Stratos absorbed doses were 2.51±1.21 σ (from 1.09 to 6.06). The highest differences were found for lungs (average ratio 4.76±2.13 σ), as expected, since Stratos considers unit density

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

    International Nuclear Information System (INIS)

    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

  6. Dosimetry of iodoantipyrine

    International Nuclear Information System (INIS)

    Dosimetry of iodoantipyrine labeled with radioactive iodine was determined by measuring the biodistribution of 131I-iodoantipyrine in 41 female rabbits. Following administration of the radiopharmaceutical, subjects were killed at 0.5, 6, 12, 17, 24, 36, and 48 h. Organs and samples of tissues and body fluids were assayed. Results were corrected for physical decay. Exponential functions were employed to describe the time-concentration curves; representative value would be the biological half life of 9.96±0.55 h for blood. Cumulated activity estimates for 123I, 125I and 131I were then computed. Extrapolation to absorbed dose in humans followed the formulation of the Medical International Radiation Dose (MIRD) Committee of the Society of Nuclear Medicine. The whole body absorbed doses are 0.7 μGray, 0.5 μGray and 2.9 μGray per MBq of 123I, 123I, and 131I administered respectively. (orig.)

  7. Spectroscopic study of biologically active glasses

    Science.gov (United States)

    Szumera, M.; Wacławska, I.; Mozgawa, W.; Sitarz, M.

    2005-06-01

    It is known that the chemical activity phenomenon is characteristic for some inorganic glasses and they are able to participate in biological processes of living organisms (plants, animals and human bodies). An example here is the selective removal of silicate-phosphate glass components under the influence of biological solutions, which has been applied in designing glasses acting as ecological fertilizers of controlled release rate of the nutrients for plants. The structure of model silicate-phosphate glasses containing the different amounts of the glass network formers, i.e. Ca 2+ and Mg 2+, as a binding components were studied. These elements besides other are indispensable of the normal growth of plants. In order to establish the function and position occupied by the particular components in the glass structure, the glasses were examined by FTIR spectroscopy (with spectra decomposition) and XRD methods. It has been found that the increasing amount of MgO in the structure of silicate-phosphate glasses causes the formation of domains the structure of which changes systematically from a structure of the cristobalite type to a structure corresponding to forsterite type. Whilst the increasing content of CaO in the structure of silicate-phosphate glasses causes the formation of domains the structure of which changes from a structure typical for cristobalite through one similar to the structure of calcium orthophosphate, to a structure corresponding to calcium silicates. The changing character of domains structure is the reason of different chemical activity of glasses.

  8. Experimental models to study cholangiocyte biology

    Institute of Scientific and Technical Information of China (English)

    Pamela S. Tietz; Xian-Ming Chen; Ai-Yu Gong; Robert C. Huebert; Anatoliy Masyuk; Tatyana Masyuk; Patrick L. Splinter; Nicholas F. LaRusso

    2002-01-01

    Cholangiocytes-the epithelial cells which line the bileducts-are increasingly recognized as importanttransporting epithelia actively involved in the absorptionand secretion of water, ions, and solutes. Thisrecognition is due in part to the recent development ofnew experimental models. New biologic concepts haveemerged including the identification and topography ofreceptors and flux proteins on the apical and/orbasolateral membrane which are involved in the molecularmechanisms of ductal bile secretion. Individually isolatedand/or perfused bile duct units from livers of rats andmice serve as new, physiologically relevant in vitromodels to study cholangiocyte transport. Biliary treedimensions and novel insights into anatomic remodeling ofproliferating bile ducts have emerged from three-dimensional reconstruction using CT scanning andsophisticated software. Moreover, new pathologicconcepts have arisen regarding the interaction ofcholangiocytes with pathogens such as Cryptosporidiumparvum. These concepts and associated methodologiesmay provide the framework to develop new therapies for the cholangiopathies, a group of important hepatobiliarydiseases in which cholangiocytes are the target cell.Tietz PS, Chen XM, Gong AY, Huebert RC, Masyuk A, MasyukT, Splinter PL, LaRusso NF. Experimental models to studycoholangiocyte biology.

  9. Cadmium silicate nanopowders for radiation dosimetry application: Luminescence and dielectric studies

    Directory of Open Access Journals (Sweden)

    B.M. Manohara

    2015-06-01

    Full Text Available Pure cadmium silicate (CdSiO3 nanophosphor was prepared by a low temperature solution combustion technique. In this technique, meso-structured silica was used as silica source. The prepared compounds were well characterized by powder X-ray diffraction (PXRD, scanning electron microscopy, high resolution transmission electron microscopy, Fourier transform infrared and UV–vis spectroscopic techniques. The PXRD peaks of as-formed sample are broad and amorphous in nature. The compound calcined at 800 °C shows pure monoclinic phase, which is the lowest temperature reported so far to obtain in this phase. The average crystallite size for phase pure compound was found to be ∼31 nm. The optical energy band gap of ∼5.6 eV was observed for the compound. Raman spectrum of the sample showed the all possible states of vibrational motions of the prepared samples. The UV irradiated samples with different dose and time with constant heating rate exhibit the thermoluminescence (TL with a well resolved glow peak at ∼160 °C. The variation of TL intensity with dosage time results that the material was found to be quite useful in radiation dosimetry. The frequency dependent dielectric constant of the prepared sample exhibits high value at low frequency and vice versa.

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

    International Nuclear Information System (INIS)

    Morphometric analysis of rat and hamster lung did not demonstrate any extensive changes in lung composition or structure following inhalation exposure to 239Pu02 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 239Pu02 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 239Pu02 for rats and hamsters

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

    International Nuclear Information System (INIS)

    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.

  12. Feasibility Study of Using PAGAT Polymer Gel Dosimeter for 3D Dosimetry Around the Reactor Core

    International Nuclear Information System (INIS)

    An important problem for samples irradiation in research reactors is determination of three dimensional dose distributions in the vicinity of reactor core. Polymer gel dosimeters can be used to measure complex three dimensional dose distributions as well as the integrated dose accurately with no dependency on the dose rate. Furthermore, as they are tissue-equivalent, they may be used as a phantom. So far, polymer gel dosimeters have been used for photon, electron, proton, neutron and heavy ions, but there is a lack of application of polymer gel dosimeters for dosimetry of the mixed field of radiation of different linear ionization concentration. In this research, PAGAT polymer gel dosimeters are fabricated in the laboratory and then were irradiated with the mixed neutron gamma field from the fission process of the Tehran Research Reactor. The gel response was determined by the nuclear magnetic resonance imaging technique as a change in the relaxation rate (R2) of the gel dosimeters. The gel response as a function of normalized dose was investigated and a bi-exponential fitting was adjusted to the dose-R2 data. The region with a linear response, is called dynamic range. The slope of the region as the sensitivity of PAGAT gels to the normalized dose resulted from the neutron-gamma mixed field, was estimated to be 1.695 s-1. The results of this research showed that PAGAT polymer gel dosimeter is a useful tool for 3D dose distribution to determine the neutron gamma mixed field.

  13. 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.

  14. Study of the improvement of TLD cards for personal neutron dosimetry

    Science.gov (United States)

    Rabie, N.; Hassan, G. M.; El-Sersy, A. R.; Ezzat, M.

    In this work, personal thermoluminescence dosimeter (TLD) cards type of GN-6770 (holder type 8806) from Harshaw were used for personal neutron dosimetry. The response of the dosimeters has been determined in terms of the personal absorbed dose and personal dose equivalent for different neutron energy components, based on the recommendations of ICRP-60 and ICRU-49. Neutron irradiation was performed using a 5 mCi Am-Be neutron source. The TLD reader, type Harshaw 6600, was installed and calibrated for accurate neutron doses equivalent to gamma-ray doses. It was found that fast neutron doses measured by TLD (badges or cards) are in agreement with those measured by neutron TE (tissue equivalent gas) ionization chambers and neutron monitors. Thermal neutron doses measured by TLD cards were overestimated when compared with those measured by neutron monitors. Additional Cd was used to reduce thermal neutron doses to be in agreement with actual thermal doses. Other configurations for TLD crystals are also suggested for accurate thermal neutron dose measurements.

  15. Design and characteristic studies on new personal Radon dosimetry bu using polycarbonate detectors

    International Nuclear Information System (INIS)

    Passive radon dosimeters, based on alpha particle etched track detectors, are widely used for the assessment of radon exposure. These methods, are often applied in environmental monitoring for a long period of time. At this research, we have developed a new method for personal radon dosimetry, with high efficiency that is based upon detection of alpha particles from 218Po and 214Po collected on the fiber glass filter, which affect the polycarbonate detector surface. The radon daughter were collected on the filter surface by passing a fixed air flow through and the polycarbonate detector is exposed by their alpha particles simultaneously. After exposure, the latent tracks on the detector will be appeared by means of electrochemical etching process which is proportional to radon dose. The air flow rate and distance between the detector and the filter are the major factors that can effect the performance of the dosimeter. The relevant experimental investigations have shown that 4cm distance between the detector and the filter and 4 lit/min air flow rate through the filter are the best conditions for design of high efficient personal radon dosimeter. The most important advantages of this method are exact, fast and convenient in application and individual dose assessment. In this paper, the optimized parameters of design are presented and discussed

  16. Personal dosimetry calculations by means of radio pharmacokinetic and gamma graphic studies

    International Nuclear Information System (INIS)

    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)

  17. Dosimetry and process control for food irradiation

    International Nuclear Information System (INIS)

    Whatever a radiation process is designed to achieve, dosimetry is fundamental to it, either as a necessary control, or to establish the process, or for research and development studies. Dosimetry provides the quantitative baseline against which the biological or chemical changes induced by radiation can be measured. In the case of irradiation of food, a minimum dose will be required to achieve the technological objective. A maximum dose will be defined by the onset of the loss of acceptable quality of the food, but upper dose limits will usually be prescribed by regulatory bodies. There is no accurate way of assessing the dose once the food has left the irradiation plant. Therefore the dose must be properly applied and verified during processing. The dose is measured using dosimeters. There are many different types of dosimeters for different applications, dose ranges and conditions of use. All dosimeters must be calibrated, with a measurement traceability chain to a national or international primary standard. This paper describes the classification of dosimeters and gives examples and their applications. Calibration and use of a typical dosimetry system used for food irradiation is then discussed, including the effects of environmental influence factors such as dose rate and temperature, and how measurement traceability can be established. Before routine processing of a product can occur, process qualification must be carried out to ensure the irradiation process produces acceptable results. An example of a dose mapping study is given, followed by discussion of some practical considerations of process control, including measurement uncertainty and how this relates to the setting of process limits

  18. Dosimetry Termoluminiscent a new personal dosimetry concept in Nicaragua

    International Nuclear Information System (INIS)

    The present work is based on to study carried out along one year April 1996 until April 1997 at a hospital that located in Managua, here to control of personal dosimetric has been taken in 20 of people that work in the same one, this has been using jointly so much pocket dosemeters (ionization chambers) and thermoluminiscent dosemeters (TLD). To comparison was made among the two systems of personal dosimetry and the varying b was shown among the same ones, considering the fact that the pocket dosemeters to be able to carry out such to delicate company ace it is it the personal dosimetry inside the radiological protection

  19. Biologic

    CERN Document Server

    Kauffman, L H

    2002-01-01

    In this paper we explore the boundary between biology and the study of formal systems (logic). In the end, we arrive at a summary formalism, a chapter in "boundary mathematics" where there are not only containers but also extainers ><, entities open to interaction and distinguishing the space that they are not. The boundary algebra of containers and extainers is to biologic what boolean algebra is to classical logic. We show how this formalism encompasses significant parts of the logic of DNA replication, the Dirac formalism for quantum mechanics, formalisms for protein folding and the basic structure of the Temperley Lieb algebra at the foundations of topological invariants of knots and links.

  20. [Theoretical and Experimental Dosimetry in Evaluation of Biological Effects of Electromagnetic Field for Portable Radio Transmitters. Report 2. Homogeneous Human Head Phantom].

    Science.gov (United States)

    Perov, S Yu; Bogacheva, E V

    2015-01-01

    Results of theoretical (numerical) and experimental electromagnetic field dosimetry for homogeneous human head phantoms are considered. The simulation and measurement results are shown. This paper presents the results of Specific Absorption Rate (SAR) evaluation in the "special anthropomorphic model" of human head, when a source of electromagnetic radio frequency field is placed in front of the face. The minimal difference is shown between measurements and simulation results in Head Simulating Liquid, which makes it possible to conduct further brain tissue simulations. The investigations show that the type of electromagnetic field source and phantom form play an important part for SAR distribution. PMID:26601543

  1. Medical radiation dosimetry theory of charged particle collision energy loss

    CERN Document Server

    McParland, Brian J

    2014-01-01

    Accurate radiation dosimetry is a requirement of radiation oncology, diagnostic radiology and nuclear medicine. It is necessary so as to satisfy the needs of patient safety, therapeutic and diagnostic optimisation, and retrospective epidemiological studies of the biological effects resulting from low absorbed doses of ionising radiation. The radiation absorbed dose received by the patient is the ultimate consequence of the transfer of kinetic energy through collisions between energetic charged particles and atoms of the tissue being traversed. Thus, the ability of the medical physicist to both measure and calculate accurately patient dosimetry demands a deep understanding of the physics of charged particle interactions with matter. Interestingly, the physics of charged particle energy loss has an almost exclusively theoretical basis, thus necessitating an advanced theoretical understanding of the subject in order to apply it appropriately to the clinical regime. ​ Each year, about one-third of the worl...

  2. Spanish National Dosimetry Bank

    International Nuclear Information System (INIS)

    The National Dosimetry Bank (BDN) was designed to be a useful instrument for the protection of exposed workers. On the basis of individual doses, in conjunction with the type of facility where they were received and the type of work involved, it is possible to monitor and control the individual conditions of an exposed worker. In addition to this primary objective, the BDN's structure and utilities are such that it can be used for applications such as determining the suitability of the working conditions in various areas of ionizing radiation applications, evaluating exposure trends and the most affected areas, and supplying statistical data that can be used for legal studies

  3. Neutron dosimetry

    International Nuclear Information System (INIS)

    A neutron irradiation facility was designed and built in order to establish a procedure for calibrating neutron monitors and dosemeters. A 185 GBq 241 Am Be source of known is used as a reference source. The irradiation facility using this source in the air provides neutron dose rates between 9 nSv s-1 and 0,5 μSv s-1. A calibrated 50 nSv s-1 thermal neutron field is obtained by using a specially designed paraffin block in conjunction with the 241 Am Be source. A Bonner multisphere spectrometer was calibrated, using a procedure based on three methods proposed by international standards. The unfold 241 Am Be neutron spectrum was determined from the Bonner spheres data and resulted in a good agreement with expected values for fluence rate, dose rate and mean energy. A dosimetric system based on the electrochemical etching of CR-39 was developed for personal dosimetry. The dosemeter badge using a (n,α) converter, the etching chamber and high frequency power supply were designed and built specially for this project. The electrochemical etching (ECE) parameters used were: a 6N KOH solution, 59 deg C, 20 kVpp cm-1, 2,0 kHz, 3 hours of ECE for thermal and intermediate neutrons and 6 hours for fast neutrons. The calibration factors for thermal, intermediate and fast neutrons were determined for this personal dosemeter. The sensitivities determined for the developed dosimetric system were (1,46± 0,09) 104 tracks cm-2 mSv-1 for thermal neutrons, (9±3) 102 tracks cm-2 mSV-1 for intermediate neutrons and (26±4) tracks cm-2 mSv-1 for fast neutrons. The lower and upper limits of detection were respectively 0,002 mSv and 0,6 mSv for thermal neutrons, 0,04 mSv and 8 mSv for intermediate neutrons and 1 mSv and 12 mSv for fast neutrons. In view of the 1990's ICRP recommendations, it is possible to conclude that the personal dosemeter described in this work is sufficiently sensitive to thermal and intermediate neutrons but fast neutron monitoring ar radiological protection level

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

    International Nuclear Information System (INIS)

    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)

  5. 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)

    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)

  6. High level radiation dosimetry in biomedical research

    International Nuclear Information System (INIS)

    The physical and biological dosimetries relating to cancer therapy with radiation were taken up at the first place in the late intercomparison on high LET radiation therapy in Japan-US cancer research cooperative study. The biological dosimetry, the large dose in biomedical research, the high dose rate in biomedical research and the practical dosimeters for pulsed neutrons or protons are outlined with the main development history and the characteristics which were obtained in the relating experiments. The clinical neutron facilities in the US and Japan involved in the intercomparison are presented. Concerning the experimental results of dosimeters, the relation between the R.B.E. compared with Chiba (Cyclotron in National Institute of Radiological Sciences) and the energy of deuterons or protons used for neutron production, the survival curves of three cultured cell lines derived from human cancers, after the irradiation of 250 keV X-ray, cyclotron neutrons of about 13 MeV and Van de Graaff neutrons of about 2 MeV, the hatchability of dry Artemia eggs at the several depths in an absorber stack irradiated by 60 MeV proton beam of 40, 120 and 200 krad, the peak skin reaction of mouse legs observed at various sets of average and instantaneous dose rates, and the peak skin reaction versus three instantaneous dose rates at fixed average dose rate of 7,300 rad/min are shown. These actual data were evaluated numerically and in relation to the physical meaning from the viewpoint of the fundamental aspect of cancer therapy, comparing the Japanese measured values to the US data. The discussion record on the high dose rate effect of low LET particles on biological substances and others is added. (Nakai, Y.)

  7. Proceedings of the V. international symposium 'Actual problems of dosimetry'

    International Nuclear Information System (INIS)

    The main topics of the workshop were: monitoring and reconstruction of radiation doses at radiation accidents, biological dosimetry and markers of radiation effects as well as normative, metrological and technical aspects of dosimetric and radiometric monitoring

  8. Proceedings of the IV International Symposium 'Actual Problems of Dosimetry'

    International Nuclear Information System (INIS)

    The main topic of the workshop were: monitoring and reconstruction of radiation doses at radiation accidents, biological dosimetry and markers of radiation effects as well as normative, metrological and technical aspects of dosimetric and radiometric monitoring

  9. 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)

    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 1650 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)

  10. Silicon diode dosimetry

    International Nuclear Information System (INIS)

    The theory of silicon dosimetry is briefly reviewed with respect to operation of these diodes without reverse bias in the short-circuit current mode. The problems of temperature dependence, radiation damage, and the dependence on photon energy are discussed. Various applications of the diodes to practical radiation dosimetry are then described with a view toward pointing out the pitfalls as well as the advantages of using these diodes for dosimetry. (author)

  11. Silicon diode dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Dixon, R.L.; Ekstrand, K.E. (Wake Forest Univ., Winston-Salem, NC (USA). Bowman Gray School of Medicine)

    1982-11-01

    The theory of silicon dosimetry is briefly reviewed with respect to operation of these diodes without reverse bias in the short-circuit current mode. The problems of temperature dependence, radiation damage, and the dependence on photon energy are discussed. Various applications of the diodes to practical radiation dosimetry are then described with a view toward pointing out the pitfalls as well as the advantages of using these diodes for dosimetry.

  12. Energy and entropy in radiation dosimetry and protection

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, A.D. [Instituto Tecnologico e Nuclear, Dept. de Proteccao Radiologica e Seguranca Nuclear (Portugal)

    2006-07-01

    In this work we present and discuss a proposal to describe the degradation of the energy of photons when they interact with matter, which can be applied in radiation dosimetry and protection. Radiation dosimetry is founded in the well known physical approach of field theory as showed by Roesch and Rossi. Fluence and energy deposited are the most fundamental quantities in radiation dosimetry allowing us to calculate absorbed dose. One of the main characteristics of absorbed dose, sometimes ignored, is that it is an intensive quantity pushing radiation dosimetry into the field of statistical physics. In radiation dosimetry it is often used what we can call collective or macroscopic concepts, such as, for example, effective energy, beam quality or beam hardening and absorbed dose. Some of these concepts are trials to describe macroscopically and with simplicity what happens microscopically with a rather higher degree of complexity. In other words, is a tentative to make a bridge between the non continuous world of atoms and photons to the continuous world of radiation protection dosimetry. In computer simulations, that allow to known accurately the energy deposited in matter, absorbed dose (or fluence) is still a very useful and used quantity; however, some issues are still open problems, source of many discussions in conferences and journals in spite of the development of microdosimetry and nano-dosimetry. In spite of that, macroscopic quantities like absorbed dose are still important quantities. One of the important and controversial open question in biological effects at low doses is the linear no threshold concept (L.N.T.). In our opinion this problem is directly related with the problem mentioned above of the bridge between microscopic and macroscopic concepts. Actually, the extrapolation to low dose region is a good expression of the challenge we have to deal in order to make the connections between both worlds, the discrete micro-world to the continuous macro

  13. Energy and entropy in radiation dosimetry and protection

    International Nuclear Information System (INIS)

    In this work we present and discuss a proposal to describe the degradation of the energy of photons when they interact with matter, which can be applied in radiation dosimetry and protection. Radiation dosimetry is founded in the well known physical approach of field theory as showed by Roesch and Rossi. Fluence and energy deposited are the most fundamental quantities in radiation dosimetry allowing us to calculate absorbed dose. One of the main characteristics of absorbed dose, sometimes ignored, is that it is an intensive quantity pushing radiation dosimetry into the field of statistical physics. In radiation dosimetry it is often used what we can call collective or macroscopic concepts, such as, for example, effective energy, beam quality or beam hardening and absorbed dose. Some of these concepts are trials to describe macroscopically and with simplicity what happens microscopically with a rather higher degree of complexity. In other words, is a tentative to make a bridge between the non continuous world of atoms and photons to the continuous world of radiation protection dosimetry. In computer simulations, that allow to known accurately the energy deposited in matter, absorbed dose (or fluence) is still a very useful and used quantity; however, some issues are still open problems, source of many discussions in conferences and journals in spite of the development of microdosimetry and nano-dosimetry. In spite of that, macroscopic quantities like absorbed dose are still important quantities. One of the important and controversial open question in biological effects at low doses is the linear no threshold concept (L.N.T.). In our opinion this problem is directly related with the problem mentioned above of the bridge between microscopic and macroscopic concepts. Actually, the extrapolation to low dose region is a good expression of the challenge we have to deal in order to make the connections between both worlds, the discrete micro-world to the continuous macro

  14. Thermo-luminescent dosimetry

    International Nuclear Information System (INIS)

    The development of paediatric radiology which began in the late 195O's has been characterised by the need to limit the dose of ionising radiation to which the child is subjected. The aim has been to keep radiation exposure as low as possible by the introduction of suitable techniques and by the development of new methods. It is therefore surprising that studies in dosimetry in the paediaytric age range have only been carried out in recent years. One reason for this may have been the fact that a suitable technique of measurement was not available at the time. The introduction of solid state dosimetry based on thermo-luminescence, first into radiotherapy (1968) and subsequently into radiodiagnosis, has made it possible to abandon the previously widely used ionisation chamber (1, 2, 3, 4, 6, 7, 10, 11, 12, 14, and 14). The purpose of the present paper is to indicate the suitability of this form of dose measurement for paediatric radiological purposes and to stimulate its application in this field. (orig.)

  15. Measurement assurance in dosimetry

    International Nuclear Information System (INIS)

    The uses of radiation in medicine and industry are today wide in scope and diversity and there is a need for reliable dosimetry in most applications. In particular, high accuracy in dosimetry is required in the therapeutic use of radiation. Consequently, calibration procedures for radiotherapy generally meet also the accuracy requirements for applications in other fields, such as diagnostic radiology, radiation protection and industrial radiation processing. The emphasis at this symposium was therefore mainly or radiotherapy dosimetry, but the meeting also included one session devoted to dosimetry in diagnostic radiology. Refs, fig and tabs

  16. Dosimetry of ionizing radiation

    International Nuclear Information System (INIS)

    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

  17. EPR Dosimetry - Present and Future

    International Nuclear Information System (INIS)

    In the past, IAEA has played a central role in stipulating research and development in EPR high-dose standardisation as well as in coordinating and organising international dose intercomparison programs, within the Member States of the United Nations from the mid-seventies till today. The future tasks of EPR dosimetry seem to tend towards different subjects such as bio markers, biological radiation effects, post-accident dose reconstruction in the environment, and retrospective human dosimetry. The latter may be considered a promising tool for epidemiology on the way to re-define radiation risk of man for chronicle radiation exposures, based on e.g. South Ural civil population and radiation workers. There are on-going international activities in the field of standardising high-level dosimetry by the American Standards on Testing and Materials (Astm), and by the International Organisation of Standards (ISO). The International Commission on Radiation Units and Measurements (ICRU) is considering the establishment of relevant recommendations concerning industrial radiation processing, but also human dose reconstruction. (Author)

  18. EPR Dosimetry - Present and Future

    Energy Technology Data Exchange (ETDEWEB)

    Regulla, D.F. [GSF - National Research Centre for Environment and Health, Institute of Radiation Protection, 85764 Neuherberg (Germany)

    1999-07-01

    In the past, IAEA has played a central role in stipulating research and development in EPR high-dose standardisation as well as in coordinating and organising international dose intercomparison programs, within the Member States of the United Nations from the mid-seventies till today. The future tasks of EPR dosimetry seem to tend towards different subjects such as bio markers, biological radiation effects, post-accident dose reconstruction in the environment, and retrospective human dosimetry. The latter may be considered a promising tool for epidemiology on the way to re-define radiation risk of man for chronicle radiation exposures, based on e.g. South Ural civil population and radiation workers. There are on-going international activities in the field of standardising high-level dosimetry by the American Standards on Testing and Materials (Astm), and by the International Organisation of Standards (ISO). The International Commission on Radiation Units and Measurements (ICRU) is considering the establishment of relevant recommendations concerning industrial radiation processing, but also human dose reconstruction. (Author)

  19. EPR dosimetry - present and future

    International Nuclear Information System (INIS)

    In the past, IAEA has played a central role in stipulating research and development in EPR high-dose standardisation as well as co-ordinating and organising international dose intercomparison programs, within the Member States of the United Nations from the mid-seventies till today. The future tasks of EPR dosimetry seem to tend towards different subjects such as biomarkers, biological radiation effects, post-accident dose reconstruction in the environment, and retrospective human dosimetry. The latter may be considered a promising tool for epidemiology on the way to re-define radiation risk of man for chronicle radiation exposures, based on e.g. South Ural civil population and radiation workers. There are on-going international activities in the field of standardising high-level dosimetry by the American Standards on Testing and Materials (ASTM), and the International Organisation of Standards (ISO) as well as those of the International Commission on Radiation Units and Measurements (ICRU) considering the establishment of relevant recommendations concerning industrial radiation processing, but also human dose reconstruction. (author)

  20. Performance studies of an optical fiber OSL/RL dosimetry system in pulsed high-intensity radiation beams

    CERN Document Server

    Ravotti, F; Dusseau, Laurent; Mukherjee, Bhaskar; Glaser, Maurice; Ravotti, Federico

    2010-01-01

    The SrS:Ce,Sm phosphor is suitable for operation in harsh radiation environments where real-time dosimetry measurements are needed to survey the Total Ionizing Dose (TID) damage in electronic components. For these applications, the OSL and RL emissions from this phosphor can be exploited by mounting the SrS crystal at the edge of a single, radiation-hard, optical fiber. In this work we present an exhaustive characterization of this real-time OSL/RL probe including stability, repeatability of the measured signals, dosimetry performance and measurements of the temporal behavior of the RI signal in pulsed particle beams. (C) 2009 Elsevier Ltd. All rights reserved.

  1. 15N in biological nitrogen fixation studies

    International Nuclear Information System (INIS)

    A bibliography with 298 references on the use of the stable nitrogen isotope 15N in the research on the biological fixation of dinitrogen is presented. The literature pertaining to this bibliography covers the period from 1975 to the middle of 1985. (author)

  2. Chemical approaches to studying stem cell biology

    Institute of Scientific and Technical Information of China (English)

    Wenlin Li; Kai Jiang; Wanguo Wei; Yan Shi; Sheng Ding

    2013-01-01

    Stem cells,including both pluripotent stem cells and multipotent somatic stem cells,hold great potential for interrogating the mechanisms of tissue development,homeostasis and pathology,and for treating numerous devastating diseases.Establishment of in vitro platforms to faithfully maintain and precisely manipulate stem cell fates is essential to understand the basic mechanisms of stem cell biology,and to translate stem cells into regenerative medicine.Chemical approaches have recently provided a number of small molecules that can be used to control cell selfrenewal,lineage differentiation,reprogramming and regeneration.These chemical modulators have been proven to be versatile tools for probing stem cell biology and manipulating cell fates toward desired outcomes.Ultimately,this strategy is promising to be a new frontier for drug development aimed at endogenous stem cell modulation.

  3. Skeletal dosimetry models for alpha-particles for use in molecular radiotherapy

    Science.gov (United States)

    Watchman, Christopher J.

    Molecular radiotherapy is a cancer treatment methodology whereby a radionuclide is combined with a biologically active molecule to preferentially target cancer cells. Alpha-particle emitting radionuclides show significant potential for use in molecular radiotherapy due to the short range of the alpha-particles in tissue and their high rates of energy deposition. Current radiation dosimetry models used to assess alpha emitter dose in the skeleton were developed originally for occupational applications. In medical dosimetry, individual variability in uptake, translocation and other biological factors can result in poor correlation of clinical outcome with marrow dose estimates determined using existing skeletal models. Methods presented in this work were developed in response to the need for dosimetry models which account for these biological and patient-specific factors. Dosimetry models are presented for trabecular bone alpha particle dosimetry as well as a model for cortical bone dosimetry. These radiation transport models are the 3D chord-based infinite spongiosa transport model (3D-CBIST) and the chord-based infinite cortical transport model (CBICT), respectively. Absorbed fraction data for several skeletal tissues for several subjects are presented. Each modeling strategy accounts for biological parameters, such as bone marrow cellularity, not previously incorporated into alpha-particle skeletal dosimetry models used in radiation protection. Using these data a study investigating the variability in alpha-particle absorbed fractions in the human skeleton is also presented. Data is also offered relating skeletal tissue masses in individual bone sites for a range of ages. These data are necessary for dose calculations and have previously only been available as whole body tissue masses. A revised 3D-CBIST model is also presented which allows for changes in endosteum thickness to account for revised target cell location of tissues involved in the radiological

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

    International Nuclear Information System (INIS)

    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

  5. Studies of whole-body retention for incorporation dosimetry in case of renal insufficiency

    International Nuclear Information System (INIS)

    Following intravenous injection of 131I hippurate, whole-body retention measurements were carried out in normal subjects and patients with pyelonephritis and varying degrees of renal insufficiency for a period of up to 74 days. The retention curves for normal subjects could be divided up into two components, one with a biological half-life of about 20 minutes (Tsub(B1)) and a zero intercept of 85-95% of total activity and a second one with a Tsub(B2) of 0.3 days and 5-15%. In diseased patients Tsub(B1) was prolonged to 2-3.6 hours, Tsub(B2) to 0.5-1.25 days. Furthermore, a third component (representing 1.4 to 10% of total activity) with a biological half-life of 35 days (Tsub(B3)) was also demonstrated: this result can be explained by the splitting off of the 131I label. Incorporation dosimetric calculations according to the MIRD conception permitted the determination of a whole-body dose increased by a factor of 2.5 to 40 for patients with renal insufficiency compared to those with healthy kidneys. In our patient material it can amount to 6,0 to 116,0 mrad in a renal sequence scintigraphy with 300 μCi 131I-hippurate. By in vivo splitting-off of 131iodine in long-time retention due to excretion insufficiency radiation doses to the unblocked thyroid between 36 and 120 rad were determined. (author)

  6. Dosimetry service removal

    CERN Multimedia

    Safety Commission

    2010-01-01

    Dear personal dosimeter user, Please note that the Dosimetry service has moved in building 55, the service is now located in the main floor: 55-R-004. Main floor instead of second floor. On your right hand when accessing in the building. Thank you Dosimetry Service

  7. Dosimetry in process control

    International Nuclear Information System (INIS)

    Measurement of absorbed dose and dose distribution in irradiated medical products relies on the use of quality dosimetry systems, trained personnel and a thorough understanding of the energy deposition process. The interrelationship of these factors will be discussed with emphasis on the current and future practices of process control dosimetry. (author)

  8. ESR dosimetry: achievements and challenges

    Energy Technology Data Exchange (ETDEWEB)

    Baffa, O., E-mail: baffa@usp.br [Universidade de Sao Paulo, Departamento de Fisica, Av. Bandeirantes 3900, 14040-901 Ribeirao Preto, Sao Paulo (Brazil)

    2015-10-15

    Full text: Electron Spin Resonance (ESR), also known as Electron Paramagnetic Resonance (EPR) and more recently as Electron Magnetic Resonance (Emr), is a spectroscopy technique able to detect unpaired electrons such as those created by the interaction ionizing radiation with matter. When the unpaired electrons created by ionizing radiation are stable over some reasonable time, ESR can be used to measure the radiation dose deposited in the material under study. In principle, any insulating material that satisfies this requisite can be used as a dosimeter. ESR has been used in retrospective dosimetry in case of radiological accidents using natural constituents of human body such as teeth, bones and nails as well as fortuitous materials as sugar, sweeteners and plastics. When using teeth the typical detected dose is 0.5 Gy for, for X-Band spectrometers (9 GHz) and even lower doses if higher frequency spectrometers are used. Clinical dosimetry is another area of potential use of this dosimetric modality. In this application the amino acid alanine has been proposed and being used. Alanine dosimeters are very easy to prepare and require no complicated treatments for use. Alanine/ESR dosimetry satisfies many of the required properties for clinical applications such as water equivalent composition, independence of response for the energy range used in therapy and high precision. Other organic materials such as ammonium tartrate are being investigated to increase the sensitivity of ESR for clinical applications. Finally, industrial applications can also benefit from this dosimetry. The challenges to expand applications, the number of users and research groups of ESR dosimetry will be discussed. (Author)

  9. ESR dosimetry: achievements and challenges

    International Nuclear Information System (INIS)

    Full text: Electron Spin Resonance (ESR), also known as Electron Paramagnetic Resonance (EPR) and more recently as Electron Magnetic Resonance (Emr), is a spectroscopy technique able to detect unpaired electrons such as those created by the interaction ionizing radiation with matter. When the unpaired electrons created by ionizing radiation are stable over some reasonable time, ESR can be used to measure the radiation dose deposited in the material under study. In principle, any insulating material that satisfies this requisite can be used as a dosimeter. ESR has been used in retrospective dosimetry in case of radiological accidents using natural constituents of human body such as teeth, bones and nails as well as fortuitous materials as sugar, sweeteners and plastics. When using teeth the typical detected dose is 0.5 Gy for, for X-Band spectrometers (9 GHz) and even lower doses if higher frequency spectrometers are used. Clinical dosimetry is another area of potential use of this dosimetric modality. In this application the amino acid alanine has been proposed and being used. Alanine dosimeters are very easy to prepare and require no complicated treatments for use. Alanine/ESR dosimetry satisfies many of the required properties for clinical applications such as water equivalent composition, independence of response for the energy range used in therapy and high precision. Other organic materials such as ammonium tartrate are being investigated to increase the sensitivity of ESR for clinical applications. Finally, industrial applications can also benefit from this dosimetry. The challenges to expand applications, the number of users and research groups of ESR dosimetry will be discussed. (Author)

  10. Usage of JENDL dosimetry file for material dosimetry in JOYO

    International Nuclear Information System (INIS)

    A cross section set with covariance error matrix for neutron spectrum unfolding has been newly prepared from JENDL-3 dosimetry file and was applied to the dosimetry test in the MK-II core (the irradiation core) of Experimental Fast Reactor 'JOYO'. The dosimetry results by the new cross section set were compared with the previous ones by ENDF/B-V dosimetry file to evaluate the applicability and accuracy for the fast reactor dosimetry. In this work, it has been concluded that more improvement can be expected for the JOYO dosimetry test by employing JENDL-3 dosimetry file. (author)

  11. Ocular brachytherapy dosimetry for 103Pd and 125I in the presence of gold nanoparticles: a Monte Carlo study.

    Science.gov (United States)

    Asadi, Somayeh; Vaez-Zadeh, Mehdi; Vahidian, Mohammad; Marghchouei, Mahdieh; Masoudi, S Farhad

    2016-01-01

    The aim of the present Monte Carlo study is to evaluate the variation of energy deposition in healthy tissues in the human eye which is irradiated by brachytherapy sources in comparison with the resultant dose increase in the gold nanoparticle (GNP)-loaded choroidal melanoma. The effects of these nanoparticles on normal tissues are compared between 103Pd and 125I as two ophthalmic brachytherapy sources. Dose distribution in the tumor and healthy tissues has been taken into account for both brachytherapy sources. Also, in certain points of the eye, the ratio of the absorbed dose by the normal tissue in the presence of GNPs to the absorbed dose by the same point in the absence of GNPs has been calculated. In addition, differences of the absorbed dose in the tumor observed in the comparison of simple water phantom and actual simulated human eye in presence of GNPs are also a matter of interest that have been considered in the present work. The difference between the eye globe and the water phantom is more obvious for 125I than that of the 103Pd when the ophthalmic dosimetry is done in the presence of GNPs. Whenever these nanoparticles are utilized in enhancing the absorbed dose by the tumor, the use of 125I brachytherapy source will greatly amplify the amount of dose enhancement factor (DEF) in the tumor site without inflicting much dam-age to healthy organs, when compared to the 103Pd source. For instance, in the concentration of 30 mg GNPs, the difference amongst the calculated DEF for 125I between these phantoms is 5.3%, while it is 2.45% for 103Pd. Furthermore, in Monte Carlo studies of eye brachytherapy, more precise definition of the eye phantom instead of a water phantom will become increasingly important when we use 125I as opposed to 103Pd. PMID:27167265

  12. New advances in pollination biology and the studies in China

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Pollination biology is the study of the various biological features in relation to the event of pollen transfer. It is one of the central concerns of plant reproductive ecology and evolutionary biology. In this paper, we attempt to introduce the main advances and some new interests in pollination biology and make a brief review of the research work that has been done in China in recent years. We also give some insights into the study that we intend to carry out in this field in the future.

  13. System chemical biology studies of endocrine disruptors

    DEFF Research Database (Denmark)

    Taboureau, Olivier; Oprea, Tudor I.

    Endocrine disrupting chemicals (EDCs) alter hormonal balance and other physiological systems through inappropriate developmental or adult exposure, perturbing the reproductive function of further generations. While disruption of key receptors (e.g., estrogen, androgen, and thyroid) at the ligand...... binding domain (LBD) has been associated with EDCs, a significant number of EDCs do not appear to influence the LBDs of these receptors. Therefore, we evaluated the potential biological effects of EDCs in humans with the aim to rationalize the etiology of certain disorders associated with the reproductive...

  14. Dosimetry of iodoantipyrine

    Energy Technology Data Exchange (ETDEWEB)

    Chu, R.Y.L.; Ekeh, S. (Oklahoma Univ., Oklahoma City, OK (USA). Dept. of Radiological Sciences; Veterans Administration Medical Center, Oklahoma City, OK (USA)); Basmadjian, G. (Oklahoma Univ., Oklahoma City, OK (USA). Dept. of Pharmaceutical Sciences)

    1989-12-01

    Dosimetry of iodoantipyrine labeled with radioactive iodine was determined by measuring the biodistribution of {sup 131}I-iodoantipyrine in 41 female rabbits. Following administration of the radiopharmaceutical, subjects were killed at 0.5, 6, 12, 17, 24, 36, and 48 h. Organs and samples of tissues and body fluids were assayed. Results were corrected for physical decay. Exponential functions were employed to describe the time-concentration curves; representative value would be the biological half life of 9.96+-0.55 h for blood. Cumulated activity estimates for {sup 123}I, {sup 125}I and {sup 131}I were then computed. Extrapolation to absorbed dose in humans followed the formulation of the Medical International Radiation Dose (MIRD) Committee of the Society of Nuclear Medicine. The whole body absorbed doses are 0.7 {mu}Gray, 0.5 {mu}Gray and 2.9 {mu}Gray per MBq of {sup 123}I, {sup 123}I, and {sup 131}I administered respectively. (orig.).

  15. Dosimetry of ionizing radiation

    International Nuclear Information System (INIS)

    The book informs of the whole range of the physical foundations of dosimetry. In the chapter dealing with the interaction of ionizing radiation with matter the processes are described of the interaction between the individual types of ionizing radiation and matter and the effects of ionizing radiation on matter. The chapter dealing with dosimetric quantities and units gives a survey and definitions of quantities and their inter-relations. The chapters relating to the determination of basic dosimetric quantities and to integral dosimetric methods give a detailed description of the individual methods. The chapter relating to radionuclides in the environment concerns the occurrence of natural radionuclides in the environment and in the human organism, cosmic radiation and artificial sources of radioactivity connected with the development of civilisation and technology. The chapter related to radiation protection gives guidelines for the calculation of shielding for individual types of radiation. The supplement contains a list of the properties of certain radionuclides widespread in the environment, their basic physico-chemical and biological characteristics, parameters of metabolism and values of maximum permissible concentrations. (M.D.)

  16. Alanine - ESR dosimetry, feasibility and possible applications

    International Nuclear Information System (INIS)

    Alanine ESR dosimetry presents a great interest for quality controls in radiotherapy. This new developed water equivalent alanine dosimeter allows a reproducible dose measurement, by a non-destructive readout technique in a large dose range. In this paper the stability of the dosimeter response has been shown but also its independence with the energy or the dose rate of the absorbed radiation. Through this different studies, one can broaden the application field of alanine / ESR dosimetry especially for in-vivo dosimetry. The results of the experiments and the intra operative treatment, indicate that this kind of dosimetry seems to be a promising technique for in-vivo quality controls in electron beam, γ ray or X ray radiotherapy. (authors)

  17. Medical dosimetry in Hungary

    Science.gov (United States)

    Turák, O.; Osvay, M.; Ballay, L.

    2012-09-01

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

  18. Dosimetry of breast cancer

    International Nuclear Information System (INIS)

    The systemic therapy of breast cancer has also changed profoundly during the last 60 years, and in this time the integration of treatment modalities involve a major area of investigation. The dosimetry of breast cancer presents different complications which can range from the Physician's handling of the neoplasia up to the simple aspects of physical simulation, contour design, radiation fields, irregular surfaces and computer programs containing mathematical equations which differ little or largely with the reality of the radiation distribution into the volume to be irradiated. We have studied the problem using two types of measurements to determine how the radiation distribution is in irregular surfaces, and designing an easier skill to be used with each patient, in order to optimize the treatment with respect to the simulation and verification process. (author). 7 refs

  19. 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

  20. PENGEMBANGAN BAHAN AJAR BIOLOGI SEL PADA PROGRAM STUDI PENDIDIKAN BIOLOGI UIN ALAUDDIN MAKASSAR

    OpenAIRE

    Muriati, St

    2015-01-01

    Learning in UIN Alauddin is still limited knowledge to students, while, one mission to improve the quality of educators Biology in terms of belief, moral and scientific attitudes have not been implemented. This is caused by a lack of learning resources that connects Biology Science and its relation to scientific Qur'an. Cell Biology as subjects that reveal about the phenomenon of the smallest unit of life, it can be studied with scientific Qur'an. Therefore, it is necessary to develop teachin...

  1. Light and drug dosimetry considerations in porphyrin precursor–based photodynamic therapy

    OpenAIRE

    2007-01-01

    This thesis concerns light and drug dosimetry for photodynamic cancer treatment – a treatment modality where a photosensitizer uses the energy of light to damage biological matter. Porphyrin precursors were used as prodrugs which are synthesized into photosensitizers inside cells. Human subjects were studied as a part of developing a treatment for non-melanotic skin cancer. A 3-hour application of a topical cream photosensitized the tumor tissue with good selectivity versus normal skin, wh...

  2. Human radiation dosimetry of 6-[{sup 18}F]FDG predicted from preclinical studies

    Energy Technology Data Exchange (ETDEWEB)

    Muzic, Raymond F., E-mail: raymond.muzic@case.edu [Department of Radiology, University Hospitals Case Medical Center, Case Western Reserve University, Cleveland, Ohio 44106 (United States); Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio 44106 (United States); Case Center for Imaging Research, University Hospitals Case Medical Center, Case Western Reserve University, Cleveland, Ohio 44106 (United States); Chandramouli, Visvanathan; Hatami, Ahmad [Department of Radiology, University Hospitals Case Medical Center, Case Western Reserve University, Cleveland, Ohio 44106 (United States); Huang, Hsuan-Ming; Wu, Chunying [Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio 44106 and Case Center for Imaging Research, University Hospitals Case Medical Center, Case Western Reserve University, Cleveland, Ohio 44106 (United States); Ismail-Beigi, Faramarz [Department of Medicine, University Hospitals Case Medical Center, Case Western Reserve University, Cleveland, Ohio 44106 (United States)

    2014-03-15

    Purpose: The authors are developing 6-[{sup 18}F]fluoro-6-deoxy-D-glucose (6-[{sup 18}F]FDG) as an in vivo tracer of glucose transport. While 6-[{sup 18}F]FDG has the same radionuclide half-life as 2-[{sup 18}F]fluoro-2-deoxy-D-glucose (2-[{sup 18}F]FDG) which is ubiquitously used for PET imaging, 6-[{sup 18}F]FDG has special biologic properties and different biodistributions that make it preferable to 2-[{sup 18}F]FDG for assessing glucose transport. In preparation for 6-[{sup 18}F]FDG use in human PET scanning, the authors would like to determine the amount of 6-[{sup 18}F]FDG to inject while maintaining radiation doses in a safe range. Methods: Rats were injected with 6-[{sup 18}F]FDG, euthanized at specified times, and tissues were collected and assayed for activity content. For each tissue sample, the percent of injected dose per gram was calculated and extrapolated to that for humans in order to construct predicted time-courses. Residence times were calculated as areas under the curves and were used as inputs to OLINDA/EXM in order to calculate the radiation doses. Results: Unlike with 2-[{sup 18}F]FDG for which the urinary bladder wall receives the highest absorbed dose due to urinary excretion, with 6-[{sup 18}F]FDG there is little urinary excretion and osteogenic cells and the liver are predicted to receive the highest absorbed doses: 0.027 mGy/MBq (0.100 rad/mCi) and 0.018 mGy/MBq (0.066 rad/mCi), respectively. Also, the effective dose from 6-[{sup 18}F]FDG, i.e., 0.013 mSv/MBq (0.046 rem/mCi), is predicted to be approximately 30% lower than that from 2-[{sup 18}F]FDG. Conclusions: 6-[{sup 18}F]FDG will be safe for use in the PET scanning of humans.

  3. Precision and accuracy of neutron dosimetry with TEP ionization chamber

    International Nuclear Information System (INIS)

    Precision of neutron dosimetry for medical irradiation could be maintained within a few percent over a year. However, accuracy or absolute dose is not well established yet. The results of neutron dosimetry intercomparison between Japan and USA showed that the agreement in both stated absolute dose was as good as 5 percents. Further studies should be made for the better establishment of neutron dosimetry both experimentally and theoretically. (author)

  4. Activities of Project 'Cooperation and development with Latin America and Iberian in Biological Dosimetry of Iberian Group of Radiation Protection Societies; Actividades del proyecto 'Cooperacion y desarrollo con Iberoamerica en dosimetria biologica' del Grupo Iberoamericano de Sociedades de Proteccion Radiologica (GRIAPRA)

    Energy Technology Data Exchange (ETDEWEB)

    Nasazzi, Nora B.; Taja, Maria R.; Giorgio, Marina di [Autoridad Regulatoria Nuclear, Buenos Aires (Argentina)]. E-mail: nnasazzi@cae.arn.gov.ar; Garcia Lima, Omar; Lamadrid, Ana I. [Centro de Proteccion y Higiene de las Radiaciones, La Habana (Cuba)]. E-mail: omar@cprh.edu.cu; Olivares, Pilar; Moreno, Mercedes; Prieto, Maria J. [Hospital General Universitario Gregorio Maranon, Madrid (Spain)]. E-mail: polivares@radonc.hggm.es; Espinosa, Marco [Instituto Peruano de Energia Nuclear, Lima (Peru)]. E-mail: mespinoza@ipen.gob.pe

    2001-07-01

    In 1996 the GRIAPRA Group (Latin American and Iberian Group of Radiation Protection Societies) was established with the participation of Argentina, Brazil, Cuba, Mexico, Peru, Portugal and Spain. In 1998 began the biennial Collaborative Working Project 'Cooperation and Development with Latin America in Biological Dosimetry', partially supported by the Extremadura Government, Spain, initially involving five countries: Argentina, Cuba, Peru, Portugal and Spain. The general aim of the project is to create an Latin American and Iberian Biological Dosimetry Laboratories Coordinated Group in order to: give mutual cooperation and to other countries if required, in the case of radiological accident; contribute to enhance the technical capabilities of the participant laboratories; promote the installment of laboratories on this field in countries that does not have it yet through the training of human resources and providing the necessary equipment and, finally, perform jointly research activities in biological dosimetry. The activities designed in order to accomplish the project specific aims for the 1998-2000 period have been achieved. Description and results are presented. (author)

  5. Dosimetry in intravascular brachytherapy

    International Nuclear Information System (INIS)

    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)

  6. The Vinca dosimetry experiment

    International Nuclear Information System (INIS)

    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

  7. Development and current state of dosimetry in Cuba

    International Nuclear Information System (INIS)

    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)

  8. Study on optical radiation of a relativistic electron beam for giving reasons for the impulse-dosimetry absolute method

    International Nuclear Information System (INIS)

    Spectral and amplitude-time characteristics of optical emission of a relativistic electron beam in air is stidied by the photoelectron method. Application of the optical method for absolute measurements of characteristics of the dose field of an impulse relativistic electron beam is considered. The distribution of the energy absorbed along the 1 MeV electron beam axis is experimentally investigated. The absolute method of impulse dosimetry of heightened accuracy is substantiated on the basis of the results obtained

  9. A comparative study on patient specific absolute dosimetry using slab phantom, acrylic body phantom and goat head phantom

    OpenAIRE

    Om Prakash Gurjar; Surendra Prasad Mishra

    2015-01-01

    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...

  10. Dosimetry of β extensive sources

    International Nuclear Information System (INIS)

    In this work, we have been studied, making use of the Penelope Monte Carlo simulation code, the dosimetry of β extensive sources in situations of spherical geometry including interfaces. These configurations are of interest in the treatment of the called cranealfaringyomes of some synovia leisure of knee and other problems of interest in medical physics. Therefore, its application can be extended toward problems of another areas with similar geometric situation and beta sources. (Author)

  11. Microbubble generation by piezotransducer for biological studies

    Science.gov (United States)

    Zhu, W.; Alkhazal, M.; Cho, M.; Xiao, S.

    2015-12-01

    Bubbles induced by blast waves or shocks are speculated to be the major cause of damages in biological cells in mild traumatic brain injuries. Microbubble collapse was found to induce noticeable cell detachment from the cell substrate, changes in focal adhesion and biomechanics. To better understand the bubble mechanism, we would like to construct a system, which allows us to clearly differentiate the impact of bubbles from that of shocks. Such a generator needs to be low profile in order to place under a microscope. A piezoelectric transducer system was designed to meet the need. The system uses either a flat or a spherical focusing piezoelectric transducer to produce microbubbles in a cuvette loaded with cell-culture medium. The transducer is placed on the side of the cuvette with its axis lining horizontally. A cover slip is placed on the top of the cuvette. The impact of the waves to the cells is minimized as the cover slip is parallel to the direction of the wave. Only bubbles from the medium reach the cover slip and interact with cells. The effect of bubbles therefore can be separated that of pressure waves. The bubbles collected on a cover slip range in size from 100 μm to 10 μm in radius, but the dominant size is 20-30 μm.

  12. Study-parameter impact in quantitative Yttrium-90 PET imaging for Radioembolization Treatment Monitoring and Dosimetry

    NARCIS (Netherlands)

    Goedicke, A.; Berker, Y.; Verburg, F. A.; Behrendt, F.F.; Winz, O.; Mottaghy, F.M.

    2013-01-01

    A small positron-generating branch in 90-Yttrium (90Y) decay enablespost-therapy dose assessment in liver cancer radioembolization treatment. The aim of this study was to validate clinical 90Y PET quantification, focusing on scanner linearity as well as acquisition and reconstruction parameter impac

  13. 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)

    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

  14. A dosimetry study comparing NCS report-2, IAEA TRS-381, AAPM TG-51 and IAEA TRS-398 for high energy photon beams

    International Nuclear Information System (INIS)

    In the last 5 years the American Association of Physicists in Medicine Task group 51 (AAPM TG-51) and the International Atomic Energy Agency (IAEA) published a new high-energy photon and electron dosimetry protocol. These protocols are based on the use of an ion chamber having an absorbed-dose to water calibration factor. These are different from the previous NCS report-2 and IAEA TRS-277 protocols, which require air kerma calibration factor, the aim of this study is to present the dose comparison between various dosimetry protocols and the IAEA TRS-398 protocol for clinical reference dosimetry of high energy photon beams. The absorbed-dose to water measured according to the NCS Report-2, International Atomic Energy Agency technical Report Series No. 277 (IAEA TRS-277) and, TG-51 are compared to that measured using the TRS-398 protocol. This study shows that the absorbed dose which is measured with The IAEA TRS-398 formalisms is higher than that calculated with NCS Report-2 and IAEA TRS-277 formalisms within range from 0.4 to 1.3% and from 0.7 to 2.1% respectively for different higher energy photon beams of Co-60, 6, 8 and 18 MV. as sensed by different ionization chambers, The chambers used are PTW 30001, 30004, and NE-2571; which have calibration factors NK and ND,W traceable to the Bureau International des Poids et Measures (BIPM). In contrast, the absorbed-dose to water measured according to TG-51 is in good agreement with TRS-398 within about 0.3% for photon beams

  15. Basic Studies on Radiation-Induced Luminescence from Natural Quartz and Its Application to Retrospective Dosimetry

    OpenAIRE

    Fujita, Hiroki; 藤田, 博喜

    2006-01-01

    It is very important to have a method of estimating radiation-dose received by people or irradiated in environmental space, without having or setting conventional dosemeters. However, dose evaluation method is not always established in the case of emergency situation. The purpose of this study was to confirm whether thermoluminescence (TL) and optically stimulated luminescence (OSL) from naturally occurring quartz could be used to estimate such accidental radiation doses or not. When ionizing...

  16. Medical staff extremity dosimetry in CT fluoroscopy: an anthropomorphic hand voxel phantom study

    Science.gov (United States)

    Figueira, C.; Becker, F.; Blunck, C.; DiMaria, S.; Baptista, M.; Esteves, B.; Paulo, G.; Santos, J.; Teles, P.; Vaz, P.

    2013-08-01

    This work aims to contribute to the study of the radiation dose distribution delivered to the hands of medical staff members during a general computed tomographic (CT) fluoroscopic guided procedure. In this study, both Monte Carlo simulations and measurements were performed. For free-in-air and computed tomography dose index (CTDI) body phantom measurements, a standard pencil ionization chamber (IC) 100 mm long was used. The CT scanner model was implemented using MCNPX (Monte Carlo N-Particle eXtended) and was successfully validated by comparing the simulated results with measurements. Subsequently, CT images of a hand, together with an anthropomorphic phantom, were voxelized and used with the MCNPX code for dose calculations. The hand dose distribution study was performed both by using thermo-luminescent detector measurements and Monte Carlo simulations. The validated simulation tool provides a new perspective for detailed investigations of CT-irradiation scenarios. Simulations show that there is a strong dose gradient, namely the even zones of the hand that are in precise vicinity to the x-ray beam only receive about 4% of the maximum dose delivered to adjacent areas which are directly exposed to the primary x-ray beam. Finally, the scatter contribution of the patient was also studied through MC simulations. The results show that for directly exposed parts of the hand surface, the dose is reduced by the body of the patient (due to the shielding), whereas the dose is increased by scattered radiation from the patient for parts of the skin that receive scattered radiation only.

  17. A study on the development of personal radiation dosimetry system based on the pulsed optically stimulated luminescence of α-Al2O3:C

    International Nuclear Information System (INIS)

    High quality radiation dosimetry is for workers who rely upon personal dosimeters to record the amount of radiation to which they are exposed. Radiation physicists have been exploring thermoluminescence dosimeter (TLD) for personal monitoring since the mid 1960s, although, widespread use has only occurred in the last 20 years as automated analytical systems and high quality TLD crystals became commercially available. nowadays, multiple TLD (thermoluminescence dosimeter) chips with appropriate physical filters are generally used for measurements of the personal dose equivalent quantities, Hp(d). Though the TLD offers several advantages not possessed by radiological film, it does not offer the some type of advantages as films: re-analysis of an exposure situation is prohibited because the analysis process clears all of the useful dosimetric traps and a record of the luminescence intensity in the form of a glow curve is all that is available after analysis. In addition, the high heating temperatures restrict packaging methods and prevent competitively priced thin films of TLD crystal powders. Optically stimulated luminescence (OSL) technology avoids many engineering limitations imposed by the high heating temperatures used for TLD technology. OSL crystalline powders can be dispersed in various plastics unable to withstand the TLD heating regimen. With uniform dispersion in the plastic, mass-manufacturing techniques can produce large quantities of identically performing detectors. The first proposal conducted by Markey et al. for applications and potentials of α-AI2O3:C for OSL dosimetry opened a new era for this phosphor. Pulsed and continuous wave OSL studies carried out on α-AI2O3:C have shown that the material seems to be the most promising for routine application of OSL for dosimetric purposes. The main objective of this study is to develop a multi-area personal OSL dosimetry system using α-AI2O3:C by taking advantage of its optical properties and energy

  18. Relative dosimetry by Ebt-3

    International Nuclear Information System (INIS)

    In the present work relative dosimetry in two linear accelerator for radiation therapy was studied. Both Varian Oncology systems named Varian Clinac 2100-Cd and MLC Varian Clinac i X were used. Gaf Chromic Ebt-3 film was used. Measurements have been performed in a water equivalent phantom, using 6 MV and 18 MV photon beams on both Linacs. Both calibration and Electron irradiations were carried out with the ionization chamber placed at the isocenter, below a stack of solid water slabs, at the depth of dose maximum (D max), with a Source-to-Surface Distance (SSD) of 100 cm and a field size of 10 cm x 10 cm. Calibration and dosimetric measurements photons were carried out under IAEA-TRS 398 protocol. Results of relative dosimetry in the present work are discussed. (Author)

  19. Dosimetry study of diagnostic X-ray using doped iodide normoxic polymer gels

    International Nuclear Information System (INIS)

    In radiotherapy, polymer gel dosimeters are used for three-dimensional (3D) dose distribution. However, the doses are within the Gy range. In this study, we attempted to develop a low-dose 3D dosimeter within the mGy range for diagnostic radiology. The effect of the iodinated compound was used as a dose enhancement sensitizer to enhance the dose sensitivity of normoxic polymer gel dosimeters. This study aims to use N-isopropylacrylamide(NIPAM)-based and methacrylic acid (MAGAT)-based gels to evaluate the potential dose enhancement sensitizer, as well as to compare two gels that may be suitable for measuring diagnostic radiation doses. The suitable formulation of NIPAM gel [5% (w/w) gelatin, 5% (w/w) NIPAM, 3% (w/w) N,N′-methylenebisacrylamide (BIS), 5 mM tetrakis (hydroxymethyl) phosphonium chloride (THPC), and 87% (w/w) deionized distilled water] and MAGAT gel (4% MAA, 9% gelatin, 87% deionized water, and 10 mM THPC) were used and loaded with clinical iodinated contrast medium agent (Iobitridol, Xenetix® 350). Irradiation was conducted using X-ray computed tomography. The irradiation doses ranged from 0 mGy to 80 mGy. Optical computed tomography was the employed gel measurement system. The results indicate that the iodinated contrast agent yields a quantifiable dose enhancement ratio. The dose enhancement ratios of NIPAM and MAGAT gels are 3.35±0.6 and 1.36±0.3, respectively. The developed NIPAM gel in this study could be suitable for measuring diagnostic radiation doses. - Highlights: • mGy range for diagnostic radiology was developed using gel dosimeter. • NIPAM and MAGAT based gels were used to evaluate diagnostic X-ray CT radiation dose. • NIPAM doped iodide gel was verified for diagnostic radiation doses measurement

  20. 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

    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...... 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, and the...

  1. 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

    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...... 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, and the...... recombination centres in one glazing type are shown to be F-centres, Cr3+ and Dy3+....

  2. A Compton imager for in-vivo dosimetry of proton beams-A design study

    International Nuclear Information System (INIS)

    In-beam SPECT during therapeutic proton beam irradiation is a novel method for three dimensional in-vivo dose verification. For this purpose a Compton camera design is evaluated with respect to the special requirements and conditions that arise from this application. Different concepts are studied by means of simulation concerning the angular resolution and efficiency. It was found that a cadmium zinc telluride system can perform sufficiently well. For further evaluation the construction of a semiconductor scintillator hybrid system is under way.

  3. A Compton imager for in-vivo dosimetry of proton beams-A design study

    Energy Technology Data Exchange (ETDEWEB)

    Kormoll, T., E-mail: thomas.kormoll@physik.tu-dresden.d [Technische Universitaet Dresden, OncoRay-Center for Radiation Research in Oncology, Fetscherstr. 74, 01307 Dresden (Germany); Fiedler, F.; Schoene, S. [Forschungszentrum Dresden-Rossendorf, Institute for Radiation Research, Bautzner Landstr. 400, 01328 Dresden (Germany); Wuestemann, J. [Technische Universitaet Dresden, OncoRay-Center for Radiation Research in Oncology, Fetscherstr. 74, 01307 Dresden (Germany); Zuber, K. [Technische Universitaet Dresden, Institute for Nuclear and Particle Physics, Zellescher Weg 19, 01069 Dresden (Germany); Enghardt, W. [Technische Universitaet Dresden, OncoRay-Center for Radiation Research in Oncology, Fetscherstr. 74, 01307 Dresden (Germany); Forschungszentrum Dresden-Rossendorf, Institute for Radiation Research, Bautzner Landstr. 400, 01328 Dresden (Germany)

    2011-01-21

    In-beam SPECT during therapeutic proton beam irradiation is a novel method for three dimensional in-vivo dose verification. For this purpose a Compton camera design is evaluated with respect to the special requirements and conditions that arise from this application. Different concepts are studied by means of simulation concerning the angular resolution and efficiency. It was found that a cadmium zinc telluride system can perform sufficiently well. For further evaluation the construction of a semiconductor scintillator hybrid system is under way.

  4. 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)

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

    International Nuclear Information System (INIS)

    The Radiation Effects Research Foundation succeeded 28 years' worth of activities of the Atomic Bomb Casualty Commission on long-term epidemiological studies in Hiroshima and Nagasaki. It has three major cohorts of atomic bomb survivors, i.e. the Life Span Study (LSS) of 120.000 people, the In Utero Cohort of 3600 and the Second Generation Study (F1) of 77 000. The LSS and F1 studies include a periodic health examination for each sub-cohort, i.e. the Adult Health Study and the F1 Clinical Study, respectively. An extensive individual dose estimation was conducted and the system was published as the Dosimetry System established in 2002 (DS02). As results of these studies, increases of cancers in relation to dose were clearly shown. Increases of other mortality causes were also observed, including heart and respiratory diseases. There has been no evidence of genetic effects in the survivors' children, including cancer and other multi-factorial diseases. The increase in the expected mortality number in the next 10 y would allow the analyses of further details of the observed effects related to atomic bomb exposures. (authors)

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

    Science.gov (United States)

    Okubo, Toshiteru

    2012-10-01

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

  7. Fricke dosimetry analysis by nuclear magnetic resonance: a comparative study with traditional methods

    International Nuclear Information System (INIS)

    Dosimetric systems are chosen according to its particular characteristics, monitoring interval and dose detection threshold. This present work proposed comparative study between Fricke dosimeter traditional with the system using polyethylene oxide (PEO) polymer instead the animal gelatin, and Nuclear Magnetic Resonance spin echo experiments. The interaction between ferrous and ferric ions with hydrogen contained in the base polymer will be investigated through the proton relaxation time distribution, T2, and the PEO as well as having a low commercial value, has a cleaner matrix, which will provide a more informative spectra. The ultraviolet spectra were also analyzed to compare the results. The process of obtaining the microscopic property T2 from the macroscopic spin echo NMR experiments is a problem classified as an ill-conditioned inverse problem. Usually, robust techniques are required to solve this kind of problem and the Hopfield neural network was chosen in this work. The T2 showed a correlation with the applied dose. As the dose is increased, the polymer protons interact more strongly with ferric ion and consequently its relaxation time decreases. The T2 distribution curve modeling assumes a multi-exponential decay in the problem, which represents a more precise theory compared with a T2 average value determination. The neural network approach was numerically stable and robust with respect to deviations in the initial conditions or experimental noises in the echo spin data and a numeric analysis was also performed. The obtained results stated this methodology as a promising tool in dosimetric systems studies. (author)

  8. Study of nuclear medicine practices in Portugal from an internal dosimetry perspective

    International Nuclear Information System (INIS)

    Nuclear medicine practices involve the handling of a wide range of pharmaceuticals labelled with different radionuclides, for diagnostic and therapeutic purposes. This work intends to evaluate the potential risks of internal contamination of nuclear medicine staff in several Portuguese nuclear medicine services and to conclude about the requirement of a routine internal monitoring. A methodology proposed by the International Atomic Energy Agency (IAEA), providing a set of criteria to determine the need, or not, for an internal monitoring programme, was applied. The evaluation of the risk of internal contaminations in a given set of working conditions is based on the type and amount of radionuclides being handled, as well as the safety conditions with which they are manipulated. The application of the IAEA criteria showed that 73.1 % of all the workers included in this study should be integrated in a routine monitoring programme for internal contaminations; more specifically, 100 % of workers performing radioimmunoassay techniques should be monitored. This study suggests that a routine monitoring programme for internal exposures should be implemented in Portugal for most nuclear medicine workers. (authors)

  9. Image guidance during breast radiotherapy: a phantom dosimetry and radiation-induced second cancer risk study

    Science.gov (United States)

    Quinn, A.; Holloway, L.; Metcalfe, P.

    2013-06-01

    Imaging procedures utilised for patient position verification during breast radiotherapy can add a considerable dose to organs surrounding the target volume on top of therapeutic scatter dose. This study investigated the dose from a breast kilovoltage cone-beam CT (kV-CBCT), a breast megavoltage fan-beam CT (MV-FBCT), and a TomoDirectTM breast treatment. Thermoluminescent dosimeters placed within a female anthropomorphic phantom were utilised to measure the dose to various organs and tissues. The contralateral breast, lungs and heart received 0.40 cGy, 0.45 cGy and 0.40 cGy from the kV-CBCT and 1.74 cGy, 1.39 cGy and 1.73 cGy from the MV-FBCT. In comparison to treatment alone, daily imaging would increase the contralateral breast, contralateral lung and heart dose by a relative 12%, 24% and 13% for the kV-CBCT, and 52%, 101% and 58% for the MV-FBCT. The impact of the imaging dose relative to the treatment dose was assessed with linear and linear-quadratic radiation-induced secondary cancer risk models for the contralateral breast. The additional imaging dose and risk estimates presented in this study should be taken into account when considering an image modality and frequency for patient position verification protocols in breast radiotherapy.

  10. Radiation induced radical in barium sulphate for ESR dosimetry: a preliminary study

    International Nuclear Information System (INIS)

    Barium sulphate (BaSO4) was irradiated by γ-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 SO3- radicals and 5G linewidth. The response to γ-ray dose ranging from 5 to 103 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 BaSO4 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

  11. Thermal dosimetry studies of ultrasonically induced hyperthermia in normal dog brain and in experimental brain tumors

    International Nuclear Information System (INIS)

    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

  12. INFORMATION: INDIVIDUAL DOSIMETRY SERVICE

    CERN Multimedia

    2004-01-01

    We inform you that the Individual Dosimetry Service will be exceptionally closed on April 13 and 14 (Tuesday and Wednesday). Only the very urgent cases will be handled during the days mentioned above.

  13. 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...... 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...... 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...

  14. Anthropometric approaches and their uncertainties to assigning computational phantoms to individual patients in pediatric dosimetry studies

    Energy Technology Data Exchange (ETDEWEB)

    Whalen, Scott [Department of Nuclear and Radiological Engineering, University of Florida, Gainesville, FL 32611 (United States); Lee, Choonsik [Department of Nuclear and Radiological Engineering, University of Florida, Gainesville, FL 32611 (United States); Williams, Jonathan L [Department of Radiology, University of Florida, Gainesville, FL 32611 (United States); Bolch, Wesley E [Departments of Nuclear and Radiological and Biomedical Engineering, University of Florida, Gainesville, FL 32611 (United States)

    2008-01-21

    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

  15. Anthropometric approaches and their uncertainties to assigning computational phantoms to individual patients in pediatric dosimetry studies

    International Nuclear Information System (INIS)

    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

  16. 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

  17. Long-term intercomparison of Spanish environmental dosimetry services. Study of transit dose estimations

    International Nuclear Information System (INIS)

    This paper presents the layout and results of a three-year follow-up of a national intercomparison campaign organized on a voluntary basis among the Spanish Laboratories in charge of environmental monitoring at and in the vicinity of Spanish nuclear installations. The dosemeters were exposed in the field at an environmental reference station with a known ambient dose equivalent, and controlled meteorological parameters. The study aimed at verifying the consistency of the different laboratories in estimating the ambient dose equivalent in realistic fields and to evaluate the influence of two different procedures to estimate the transit dose during the transfer of the dosemeters both from and to the dosimetric laboratory and the monitored site. All the results were within 20% of the reference doses for all the dosemeters tested, and in most cases they were within 10%

  18. Direct tumor in vivo dosimetry in highly-conformal radiotherapy: A feasibility study of implantable MOSFETs for hypofractionated extracranial treatments using the Cyberknife system

    Energy Technology Data Exchange (ETDEWEB)

    Scalchi, Paolo; Righetto, Roberto; Cavedon, Carlo; Francescon, Paolo; Colombo, Federico [Department of Medical Physics, San Bortolo City Hospital, Vicenza 36100 (Italy); Stereotactic Radiosurgery Center, San Bortolo City Hospital, Vicenza 36100 (Italy)

    2010-04-15

    Purpose: In highly-conformal radiotherapy, due to the complexity of both beam configurations and dose distributions, traditional in vivo dosimetry is unpractical or even impossible. The ideal dosimeter would be implanted inside the planning treatment volume so that it can directly measure the total delivered dose during each fraction with no additional uncertainty due to calculation models. The aim of this work is to verify if implantable metal oxide semiconductors field effect transistors (MOSFETs) can achieve a sufficient degree of dosimetric accuracy when used inside extracranial targets undergoing radiotherapy treatments using the Cyberknife system. Methods: Based on the preliminary findings of this study, new prototypes for high dose fractionations were developed to reduce the time dependence for long treatment delivery times. These dosimeters were recently cleared and are marketed as DVS-HFT. Multiple measurements were performed using both Virtual Water and water phantoms to characterize implantable MOSFETs under the Cyberknife beams, and included the reference-dosimetry consistency, the dependence of the response on the collimator size, on the daily delivered dose, and the time irradiation modality. Finally a Cyberknife prostate treatment simulation using a body phantom was conducted, and both MOSFET and ionization readings were compared to Monte Carlo calculations. The feasibility analysis was conducted based on the ratios of the absorbed dose divided by the dose reading, named as ''further calibration factor'' (FCF). Results: The average FCFs resulted to be 0.98 for the collimator dependence test, and about 1.00 for the reference-dosimetry test, the dose-dependence test, and the time-dependence test. The average FCF of the prostate treatment simulation test was 0.99. Conclusions: The obtained results are well within DVS specifications, that is, the factory calibration is still valid for such kind of treatments using the Cyberknife

  19. Direct tumor in vivo dosimetry in highly-conformal radiotherapy: A feasibility study of implantable MOSFETs for hypofractionated extracranial treatments using the Cyberknife system

    International Nuclear Information System (INIS)

    Purpose: In highly-conformal radiotherapy, due to the complexity of both beam configurations and dose distributions, traditional in vivo dosimetry is unpractical or even impossible. The ideal dosimeter would be implanted inside the planning treatment volume so that it can directly measure the total delivered dose during each fraction with no additional uncertainty due to calculation models. The aim of this work is to verify if implantable metal oxide semiconductors field effect transistors (MOSFETs) can achieve a sufficient degree of dosimetric accuracy when used inside extracranial targets undergoing radiotherapy treatments using the Cyberknife system. Methods: Based on the preliminary findings of this study, new prototypes for high dose fractionations were developed to reduce the time dependence for long treatment delivery times. These dosimeters were recently cleared and are marketed as DVS-HFT. Multiple measurements were performed using both Virtual Water and water phantoms to characterize implantable MOSFETs under the Cyberknife beams, and included the reference-dosimetry consistency, the dependence of the response on the collimator size, on the daily delivered dose, and the time irradiation modality. Finally a Cyberknife prostate treatment simulation using a body phantom was conducted, and both MOSFET and ionization readings were compared to Monte Carlo calculations. The feasibility analysis was conducted based on the ratios of the absorbed dose divided by the dose reading, named as ''further calibration factor'' (FCF). Results: The average FCFs resulted to be 0.98 for the collimator dependence test, and about 1.00 for the reference-dosimetry test, the dose-dependence test, and the time-dependence test. The average FCF of the prostate treatment simulation test was 0.99. Conclusions: The obtained results are well within DVS specifications, that is, the factory calibration is still valid for such kind of treatments using the Cyberknife system, with no need of

  20. Individual Dosimetry Service

    CERN Multimedia

    2004-01-01

    Individual Dosimetry Service will be closed on Thursday 9 September (Jeûne genevois) and on Friday 10 September. We inform all staffs and users under regular dosimetry control that the dosimeters for the monitoring period SEPTEMBER-OCTOBER 2004 are available from their usual dispatchers. Please have your films changed before the 13 SEPTEMBER 2004. The color of the dosimeter valid in SEPTEMBER-OCTOBER 2004 is RED.

  1. News on personal dosimetry

    International Nuclear Information System (INIS)

    What is going on in personal monitoring? The DIS-1 dosimeter (Rados/Mirion Technologies), on the market since 2000, is being introduced in the 4th dosimetry service in Switzerland. In Germany, dosimetry services are looking for alternatives to the film dosimeter. They have recently taken the decision for two technical solutions. IEC has published a standard which shall regulate technical requirements for dosimeters world-wide. (orig.)

  2. Depth dependence of electron backscatter: An energy spectral and dosimetry study using Monte Carlo simulation

    Energy Technology Data Exchange (ETDEWEB)

    Chow, James C. L.; Owrangi, Amir M. [Department of Radiation Physics, Princess Margaret Hospital and Department of Radiation Oncology, University of Toronto, Toronto, Ontario M5G 2M9 (Canada); Department of Physics, University of Waterloo, Waterloo, Ontario N2L 3G1 (Canada) and Department of Physics, Ryerson University, Toronto, Ontario M5B 2K3 (Canada); Department of Radiation Physics, Princess Margaret Hospital, Toronto, Ontario M5G 2M9 (Canada)

    2009-02-15

    This study investigated the depth dependence of electron backscatter from a layer of lead (Pb) for clinical electron beams. The change in the electron backscatter with variation in the water depth above the Pb was determined. Electron energy spectra and relative depth doses as a function of depth in water over the Pb layer were calculated using a Monte Carlo simulation and studied. Phase-space files for 4 and 9 MeV electron beams (10x10 cm{sup 2} applicator and cutout) based on the Varian 21 EX linear accelerator were generated using the EGSnrc-based BEAMNRC code. 3 mm of Pb, at depths of 0.5 and 1 cm in water, was irradiated with electrons. The source-to-surface distance is equal to 100 cm. Electron energy spectra and relative depth doses with and without the presence of the Pb layer at different depths in water were determined using the BEAMNRC code. For the 4 MeV electron energy spectra at a depth of 0.5 cm in water, electron backscatter was found to originate at the Pb-water interface and extend to 0.5 cm above the Pb insert. However, at a depth of 1 cm in water, electron backscatter almost disappeared at 0.5 and 1 cm above th ePb insert. This is due to the increased attenuation of the incident 4 MeV electron beam in a thicker layer of water as well as increased attenuation of the electron backscatter above the Pb. This resulted in a 23% decrease in relative dose at a measurement point of 0.5 cm depth, when the depth of the Pb insert was changed from 1 to 0.5 cm. For the electron energy spectra of the 9 MeV beams with a 0.5 cm depth of water, only a small amount of electron backscatter was observed. However, more electron backscatter was found when the water depth was increased to 1 cm. This is because the electron beam energy was decreased more due to the increase in attenuation from the increased depth of water compared to 0.5 cm. Since the electron energy spectrum and relative depth dose above the Pb layer vary with depth of water on top of the Pb, the

  3. Depth dependence of electron backscatter: An energy spectral and dosimetry study using Monte Carlo simulation

    International Nuclear Information System (INIS)

    This study investigated the depth dependence of electron backscatter from a layer of lead (Pb) for clinical electron beams. The change in the electron backscatter with variation in the water depth above the Pb was determined. Electron energy spectra and relative depth doses as a function of depth in water over the Pb layer were calculated using a Monte Carlo simulation and studied. Phase-space files for 4 and 9 MeV electron beams (10x10 cm2 applicator and cutout) based on the Varian 21 EX linear accelerator were generated using the EGSnrc-based BEAMNRC code. 3 mm of Pb, at depths of 0.5 and 1 cm in water, was irradiated with electrons. The source-to-surface distance is equal to 100 cm. Electron energy spectra and relative depth doses with and without the presence of the Pb layer at different depths in water were determined using the BEAMNRC code. For the 4 MeV electron energy spectra at a depth of 0.5 cm in water, electron backscatter was found to originate at the Pb-water interface and extend to 0.5 cm above the Pb insert. However, at a depth of 1 cm in water, electron backscatter almost disappeared at 0.5 and 1 cm above th ePb insert. This is due to the increased attenuation of the incident 4 MeV electron beam in a thicker layer of water as well as increased attenuation of the electron backscatter above the Pb. This resulted in a 23% decrease in relative dose at a measurement point of 0.5 cm depth, when the depth of the Pb insert was changed from 1 to 0.5 cm. For the electron energy spectra of the 9 MeV beams with a 0.5 cm depth of water, only a small amount of electron backscatter was observed. However, more electron backscatter was found when the water depth was increased to 1 cm. This is because the electron beam energy was decreased more due to the increase in attenuation from the increased depth of water compared to 0.5 cm. Since the electron energy spectrum and relative depth dose above the Pb layer vary with depth of water on top of the Pb, the electron

  4. Depth dependence of electron backscatter: an energy spectral and dosimetry study using Monte Carlo simulation.

    Science.gov (United States)

    Chow, James C L; Owrangi, Amir M

    2009-02-01

    This study investigated the depth dependence of electron backscatter from a layer of lead (Pb) for clinical electron beams. The change in the electron backscatter with variation in the water depth above the Pb was determined. Electron energy spectra and relative depth doses as a function of depth in water over the Pb layer were calculated using a Monte Carlo simulation and studied. Phase-space files for 4 and 9 MeV electron beams (10 x 10 cm2 applicator and cutout) based on the Varian 21 EX linear accelerator were generated using the EGSnrc-based BEAMNRC code. 3 mm of Pb, at depths of 0.5 and 1 cm in water, was irradiated with electrons. The source-to-surface distance is equal to 100 cm. Electron energy spectra and relative depth doses with and without the presence of the Pb layer at different depths in water were determined using the BEAMNRC code. For the 4 MeV electron energy spectra at a depth of 0.5 cm in water, electron backscatter was found to originate at the Pb-water interface and extend to 0.5 cm above the Pb insert. However, at a depth of 1 cm in water, electron backscatter almost disappeared at 0.5 and 1 cm above th ePb insert. This is due to the increased attenuation of the incident 4 MeV electron beam in a thicker layer of water as well as increased attenuation of the electron backscatter above the Pb. This resulted in a 23% decrease in relative dose at a measurement point of 0.5 cm depth, when the depth of the Pb insert was changed from 1 to 0.5 cm. For the electron energy spectra of the 9 MeV beams with a 0.5 cm depth of water, only a small amount of electron backscatter was observed. However, more electron backscatter was found when the water depth was increased to 1 cm. This is because the electron beam energy was decreased more due to the increase in attenuation from the increased depth of water compared to 0.5 cm. Since the electron energy spectrum and relative depth dose above the Pb layer vary with depth of water on top of the Pb, the electron

  5. SU-E-J-156: Preclinical Inverstigation of Dynamic Tumor Tracking Using Vero SBRT Linear Accelerator: Motion Phantom Dosimetry Study

    Energy Technology Data Exchange (ETDEWEB)

    Mamalui-Hunter, M; Wu, J; Li, Z; Su, Z [University of Florida/Radiation Oncology, Jacksonville, FL (United States)

    2014-06-01

    Purpose: Following the ‘end-to-end testing’ paradigm of Dynamic Target Tracking option in our Image-Guided dedicated SBRT VeroTM linac, we verify the capability of the system to deliver planned dose to moving targets in the heterogeneous thorax phantom (CIRSTM). The system includes gimbaled C-band linac head, robotic 6 degree of freedom couch and a tumor tracking method based on predictive modeling of target position using fluoroscopically tracked implanted markers and optically tracked infrared reflecting external markers. Methods: 4DCT scan of the motion phantom with the VisicoilTM implanted marker in the close vicinity of the target was acquired, the ‘exhale’=most prevalent phase was used for planning (iPlan by BrainLabTM). Typical 3D conformal SBRT treatment plans aimed to deliver 6-8Gy/fx to two types of targets: a)solid water-equivalent target 3cm in diameter; b)single VisicoilTM marker inserted within lung equivalent material. The planning GTV/CTV-to-PTV margins were 2mm, the block margins were 3 mm. The dose calculated by MonteCarlo algorithm with 1% variance using option Dose-to-water was compared to the ion chamber (CC01 by IBA Dosimetry) measurements in case (a) and GafchromicTM EBT3 film measurements in case (b). During delivery, the target 6 motion patterns available as a standard on CIRSTM motion phantom were investigated: in case (a), the target was moving along the designated sine or cosine4 3D trajectory; in case (b), the inserted marker was moving sinusoidally in 1D. Results: The ion chamber measurements have shown the agreement with the planned dose within 1% under all the studied motion conditions. The film measurements show 98.1% agreement with the planar calculated dose (gamma criteria: 3%/3mm). Conclusion: We successfully verified the capability of the SBRT VeroTM linac to perform real-time tumor tracking and accurate dose delivery to the target, based on predictive modeling of the correlation between implanted marker motion and

  6. Study of a method based on TLD detectors for in-phantom dosimetry in BNCT

    International Nuclear Information System (INIS)

    A method has been developed, based on thermoluminescent dosemeters (TLD), aimed at measuring the absorbed dose in tissue-equivalent phantoms exposed to thermal or epithermal neutrons, separating the contributions of various secondary radiation generated by neutrons. The proposed method takes advantage of the very low sensitivity of CaF2:Tm (TLD-300) to low energy neutrons and to the different responses to thermal neutrons of LiF:Mg,Ti dosemeters with different 6Li percentage (TLD-100, TLD-700, TLD-600). The comparison of the results with those obtained by means of gel dosemeters and activation foils has confirmed the reliability of the method. The experimental modalities allowing reliable results have been studied. The glow curves of TLD-300 after gamma or neutron irradiation have been compared; moreover, both internal irradiation effect and energy dependence have been investigated. For TLD-600, TLD-100 and TLD-700, the suitable fluence limits have been determined in order to avoid radiation damage and loss of linearity. (authors)

  7. Study of the luminescence properties of dental materials for their use in accidental dosimetry

    International Nuclear Information System (INIS)

    Full text: The current social and political situation in many world areas and the increasing hostilities between countries and cultures have accentuated the risk of a malicious use of ionising radiations. Terrorist attacks with the intentional disseminations of radioactive materials in urban settlements may involve a large number of persons, and a rapid estimation of the severity of the exposure is required for undertaking suitable protective actions and supporting decision making. Promising methodologies for a prompt dose evaluation, are those exploiting the luminescence and dosimetric properties of objects and materials which can be easily found in the contaminated area. Among these objects, dental materials have the advantage to be on contact with human body and they could therefore represent individual dosimeters in case of accidental exposure to ionising radiation. The interest in the use of dental ceramics for dosimetric purposes dates back to late 1970, however, it is only through the use of high-sensitive experimental techniques and instrumentation today available, that the potentiality of such materials as accidental dosimeters can be exploited. Moreover, innovative materials are being continuously introduced into the market, containing new additives and pigments with peculiar optical properties. In this study, Thermally Stimulated Luminescence (TSL) and Optically Stimulated Luminescence (OSL) techniques are applied to investigate the luminescence and dosimetric properties of several dental materials, including resins, glass and feldspatic ceramics, and also zirconia and alumina based ceramics, being their use widely increased in the recent years in substitution of metal cores. (author)

  8. Systems biology studies of Aspergilli - from sequence to science

    DEFF Research Database (Denmark)

    Andersen, Mikael Rørdam

    2008-01-01

    The recent dawn of the new biological mindset called systems biology has put forth a new way of analyzing and understanding biology. Carried by the notion that no element of a cell is an island, systems biology takes a holistic approach, and attempts to understand life as systems that have co...... transcriptomic to mention a few. The recent publication of the genome sequences of several filamentous fungi of the Aspergillus species (Aspergilli), has, along with the accumulation of years of reductionist studies, been a catalyst for the application of systems biology to this interesting group of fungi. Among...... the genome sequenced Aspergilli are a known human pathogen (Aspergillus fumigatus), a model organism for cellular mechanisms (Aspergillus nidulans) and two industrial workhorses (Aspergillus niger and Aspergillus oryzae). In the presented work, new analytical and computational tools have been designed...

  9. Study of radiation effects on some glasses and their applications in radiation dosimetry

    International Nuclear Information System (INIS)

    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; Li2B4O7 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 B2O3 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 that the

  10. 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.

  11. Study on Dosimetry Used TLD Dosimeter and Body Mass Index at Total Body Irradiation

    International Nuclear Information System (INIS)

    The aim of study is to expose a more uniform dose depending on the relationship between a body mass index in patients who underwent radiation therapy and an acquired dosimetric information by using a thermoluminescent dosimeter. Since 2006 to August 2011 we investigated 28 people who underwent radiation therapy were enrolled in AMC. Each patient was measured on the head, neck, chest, abdomen, pelvis, thigh, knee joint, and ankle joint using the thermoluminescent dosimeter. The measurement value of each points compared with the prescribed center point, abdominal point, and dose measurements of points on which to base the abdomen and the patient's body mass index (BMI) were compared with reference point, abdomen dose. 28 patients on prescribed dose in the abdomen by which the center point, an average dose was 100.6±5.5, and the other seven measuring points with the average maximum difference among the head, neck, chest, pelvic, thigh, knee, and ankle were 92.8±4.2%, 97.6±6.2%, 96.4±5.5%, 102.6±5.3%, 103.4±7.9%, 95.8±5.9%, 96.1±5.5%. The relationship of abdominal point dose and the patient's body mass index (BMI) was analyzed a scatter plot, and the result of linear relationship analysis by regression method, the regression of the dose (y) was -1.009 BMI (x) plus 123.3 and coefficient of determination (R2) was represented 0.697. The total body irradiation treatment process was evaluated the dose deviation and then the prescribed dose by which the average abdominal dose was satisfied with 100.6±5.5%. Results of the relationship analysis between BMI and dose, if we apply the correction value for each patients, it can be achieved more uniform dose delivery.

  12. Dosimetry and Calibration Section

    International Nuclear Information System (INIS)

    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

  13. TRUS-probe integrated MOSkin detectors for rectal wall in vivo dosimetry in HDR brachytherapy: In phantom feasibility study

    International Nuclear Information System (INIS)

    The increasing complexity and high amount of dose per fraction delivered in prostate high dose rate (HDR) brachytherapy treatments call for the implementation of accurate and effective methods for the systematic and independent quality control of the overall treatment procedure. In this study, MOSkin detectors were placed on a trans-rectal ultrasound (TRUS) probe with the aim of performing both imaging and real time rectal wall in vivo dosimetry with the use of just one single instrument. After an adequate calibration of the detectors, which was carried out in a solid water phantom, the use of MOSkins integrated to the TRUS probe was studied in a gel phantom with a typical (simplified) prostate implant. Measured and calculated doses from the treatment planning system were compared, with a resulting very low average discrepancy of −0.6 ± 2.6%. The results are very promising and of particular clinical importance, however, further in vivo investigation is planned to validate the proposed method. - Highlights: • MOSkins were placed on a TRUS probe to perform rectal wall in vivo dosimetry. • Their response was studied in a gel phantom including a typical prostate implant. • The average discrepancy between calculated and measured dose was −0.6 ± 2.6%

  14. Biological - Elwha River Dam Removal Study

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This study examines the ecosystem response of the Elwha River to the removal of the Elwha River dams. We will measure the following attributes of ecosystem...

  15. Scientific days on electromagnetic fields: from dosimetry to human health - Conference proceedings

    International Nuclear Information System (INIS)

    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

  16. Development of 111In DOTMP for dosimetry of bone pain palliation agents

    International Nuclear Information System (INIS)

    Particle emitter 1,4,7,10-tetraazacyclododecane-1,4,7,10 tetraethylene phosphonic acid complexes (DOTMP) are used for delivering high doses to bone marrow as well as palliative therapy. In this research production, quality control and biodistribution studies of [111In]-DOTMP with respect to its radiochemical and in vivo biological characteristics have been presented for imaging as well as dosimetry studies of therapeutic analogs. [111In]-DOTMP complex was obtained in high radiochemical purity (>99 %, ITLC) under at optimized conditions. This complex exhibited excellent in vitro stability at room temperature and human serum. Biodistribution studies in rats showed favorable selective skeletal uptake with rapid clearance from blood along with insignificant accumulation of activity in other non-target organs using tissue dissection and single-photon emission computed tomography (SPECT). This tracer can be used in the long term skeletal studies in SPECT procedures as well as presenting a dosimetry probe for therapeutic DOTMP analogs. (author)

  17. Radon progeny as an experimental tool for dosimetry of nanoaerosols

    International Nuclear Information System (INIS)

    The study of aerosol exposure and dosimetry measurements and related quantitation of health effects are important to the understanding of the consequences of air pollution, and are discussed widely in the scientific literature. During the last 10 years the need to correlate aerosol exposure and biological effects has become especially important due to rapid development of a new, revolutionary industry — nano technology. Nano product commerce is predicted to top $1 trillion by 2015. Quantitative assessment of aerosol particle behavior in air and in lung deposition, and dosimetry in different parts of the lung, particularly for nano aerosols, remains poor despite several decades of study. Direct measurements on humans are still needed in order to validate the hollow cast, animal studies, and lung deposition modeling. We discuss here the use of nano scale radon decay products as an experimental tool in the study of local deposition and lung dosimetry for nano aerosols. The issue of the safe use of radon progeny in such measurements is discussed based on a comparison of measured exposure in 3 settings: general population, miners, and in a human experiment conducted at the Paul Scherer Institute (PSI) in Switzerland One of the properties of radon progeny is that they consist partly of 1 nm radioactive particles called unattached activity; having extremely small size and high diffusion coefficients, these particles can be potentially useful as radioactive tracers in the study of nanometer-sized aerosols. We present a theoretical and experimental study of the correlation between the unattached activity and aerosol particle surface area, together with a description of its calibration and method for measurement of the unattached fraction. (author)

  18. RADON PROGENY AS AN EXPERIMENTAL TOOL FOR DOSIMETRY OF NANOAEROSOLS

    Energy Technology Data Exchange (ETDEWEB)

    Ruzer, Lev; Ruzer, Lev S.; Apte, Michael G.

    2008-02-25

    The study of aerosol exposure and dosimetry measurements and related quantitation of health effects are important to the understanding of the consequences of air pollution, and are discussed widely in the scientific literature. During the last 10 years the need to correlate aerosol exposure and biological effects has become especially important due to rapid development of a new, revolutionary industry ?-- nanotechnology. Nanoproduct commerce is predicted to top $1 trillion by 2015. Quantitative assessment of aerosol particle behavior in air and in lung deposition, and dosimetry in different parts of the lung, particularly for nanoaerosols, remains poor despite several decades of study. Direct measurements on humans are still needed in order to validate the hollow cast, animal studies, and lung deposition modeling. We discuss here the use of nanoscale radon decay products as an experimental tool in the study of local deposition and lung dosimetry for nanoaerosols. The issue of the safe use of radon progeny in such measurements is discussed based on a comparison of measured exposure in 3 settings: general population, miners, and in a human experiment conducted at the Paul Scherer Institute (PSI) in Switzerland. One of the properties of radon progeny is that they consist partly of 1 nm radioactive particles called unattached activity; having extremely small size and high diffusion coefficients, these particles can be potentially useful as radioactive tracers in the study of nanometer-sized aerosols. We present a theoretical and experimental study of the correlation between the unattached activity and aerosol particle surface area, together with a description of its calibration and method for measurement of the unattached fraction.

  19. Fast neutron dosimetry: Progress summary

    International Nuclear Information System (INIS)

    The purpose was to investigate the radiological physics and biology of very low energy photons derived from a 1-GeV electron synchrotron storage ring. An extensive beam line and irradiation apparatus was designed, developed, and constructed. Dosimetry measurements required invention and testing of a miniature absolute calorimeter and a cell irradiation fixture suitable for scanning exposures under computer control. Measurements of the kerma factors of oxygen, aluminum and silicon for 14-20 MeV neutrons. Custom designed miniature proportional counters of cylindrical symmetry were employed in these determinations. The oxygen kerma factor was found significantly lower than values calculated from microscopic cross sections. We also tested Mg and Fe walled conventional spherical counters. The direct neutron-counting gas interaction is significant enough for these counters that a correction is needed. We also investigated the application of Nuclear Magnetic Resonance spectroscopy to radiation dosimetry. Our purpose was to take advantage of recent development of very high-field magnets, complex RF-pulse techniques for solvent suppression, and improved spectral analysis techniques

  20. Feasibility study on the investigation of age-dependent effects of high-fre quency electromagnetic fields based on relevant biophysical and biological parameters. Final report

    International Nuclear Information System (INIS)

    Based on a comprehensive literature study on the potential health hazard for children due to high frequency electromagnetic fields compared to adults the actual status of scientific knowledge is compiled and documented. The analysis of the available scientific literature can neither divert nor confirm indications on age dependent effects of electromagnetic fields. Concerning dosimetry the open questions result mainly from the missing representative detailed anatomic body or head models for children and missing data on possible age dependent dielectric tissue properties. There is also missing information on the maximum transmission power fluctuation range and the maximum antenna current close to the head of children using the mobile telephone which is dependent on the telephone type. The dosimetry related open questions can be defined and categorized, - the questions concerning the biological effects are more complicated, since up to now no assured low-dose mechanism is available. The so far published papers are controversial and were performed mostly with small animals and whole-body exposure. Due to the multitude of open questions concerning doses and biological effects it is not yet clear whether the health hazards for children due to HF fields are higher compared to adults or not. The study recommends the main research fields to be treated in the next future

  1. Nuclear magnetic resonance studies of biological systems

    International Nuclear Information System (INIS)

    The difference between intracellular and extracellular proton relaxation rates provides the basis for the determination of the mean hemoglobin concentration (MHC) in red blood cells. The observed water T1 relaxation data from red blood cell samples under various conditions were fit to the complete equation for the time-dependent decay of magnetization for a two-compartment system including chemical exchange. The MHC for each sample was calculated from the hematocrit and the intracellular water fraction as determined by NMR. The binding of the phosphorylcholine (PC) analogue, 2-(trimethylphosphonio)-ethylphosphate (phosphoryl-phosphocholine, PPC) to the PC binding myeloma proteins TEPC-15, McPC 603, and MOPC 167 was studied by 31P NMR

  2. Dosimetry of ionising radiation in modern radiation oncology.

    Science.gov (United States)

    Kron, Tomas; Lehmann, Joerg; Greer, Peter B

    2016-07-21

    Dosimetry of ionising radiation is a well-established and mature branch of physical sciences with many applications in medicine and biology. In particular radiotherapy relies on dosimetry for optimisation of cancer treatment and avoidance of severe toxicity for patients. Several novel developments in radiotherapy have introduced new challenges for dosimetry with small and dynamically changing radiation fields being central to many of these applications such as stereotactic ablative body radiotherapy and intensity modulated radiation therapy. There is also an increasing awareness of low doses given to structures not in the target region and the associated risk of secondary cancer induction. Here accurate dosimetry is important not only for treatment optimisation but also for the generation of data that can inform radiation protection approaches in the future. The article introduces some of the challenges and highlights the interdependence of dosimetric calculations and measurements. Dosimetric concepts are explored in the context of six application fields: reference dosimetry, small fields, low dose out of field, in vivo dosimetry, brachytherapy and auditing of radiotherapy practice. Recent developments of dosimeters that can be used for these purposes are discussed using spatial resolution and number of dimensions for measurement as sorting criteria. While dosimetry is ever evolving to address the needs of advancing applications of radiation in medicine two fundamental issues remain: the accuracy of the measurement from a scientific perspective and the importance to link the measurement to a clinically relevant question. This review aims to provide an update on both of these. PMID:27351409

  3. Dosimetry of ionising radiation in modern radiation oncology

    Science.gov (United States)

    Kron, Tomas; Lehmann, Joerg; Greer, Peter B.

    2016-07-01

    Dosimetry of ionising radiation is a well-established and mature branch of physical sciences with many applications in medicine and biology. In particular radiotherapy relies on dosimetry for optimisation of cancer treatment and avoidance of severe toxicity for patients. Several novel developments in radiotherapy have introduced new challenges for dosimetry with small and dynamically changing radiation fields being central to many of these applications such as stereotactic ablative body radiotherapy and intensity modulated radiation therapy. There is also an increasing awareness of low doses given to structures not in the target region and the associated risk of secondary cancer induction. Here accurate dosimetry is important not only for treatment optimisation but also for the generation of data that can inform radiation protection approaches in the future. The article introduces some of the challenges and highlights the interdependence of dosimetric calculations and measurements. Dosimetric concepts are explored in the context of six application fields: reference dosimetry, small fields, low dose out of field, in vivo dosimetry, brachytherapy and auditing of radiotherapy practice. Recent developments of dosimeters that can be used for these purposes are discussed using spatial resolution and number of dimensions for measurement as sorting criteria. While dosimetry is ever evolving to address the needs of advancing applications of radiation in medicine two fundamental issues remain: the accuracy of the measurement from a scientific perspective and the importance to link the measurement to a clinically relevant question. This review aims to provide an update on both of these.

  4. Radiation chemical dosimetry by means of nitrate-nitrite

    International Nuclear Information System (INIS)

    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

  5. Radiation chemical dosimetry by means of nitrate-nitrite

    International Nuclear Information System (INIS)

    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 radiolisis are also treated. The possibility of application in dosimetric areas useful in radiosterilization and industrial processes is studied too. (author)

  6. New dosimetry of atomic bomb radiations.

    Science.gov (United States)

    Fry, R J; Sinclair, W K

    1987-10-10

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

  7. 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

  8. Secondary standard dosimetry laboratory (SSDL)

    International Nuclear Information System (INIS)

    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)

  9. 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)

    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, 90Sr/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 90Sr/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 H2SO4, 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 at

  10. Topics in radiation dosimetry radiation dosimetry, v.1

    CERN Document Server

    Attix, Frank H

    2013-01-01

    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

  11. Review of retrospective dosimetry techniques for external ionising radiation exposures

    International Nuclear Information System (INIS)

    The current focus on networking and mutual assistance in the management of radiation accidents or incidents has demonstrated the importance of a joined-up approach in physical and biological dosimetry. To this end, the European Radiation Dosimetry Working Group 10 on 'Retrospective Dosimetry' has been set up by individuals from a wide range of disciplines across Europe. Here, established and emerging dosimetry methods are reviewed, which can be used immediately and retrospectively following external ionising radiation exposure. Endpoints and assays include dicentrics, translocations, premature chromosome condensation, micronuclei, somatic mutations, gene expression, electron paramagnetic resonance, thermoluminescence, optically stimulated luminescence, neutron activation, haematology, protein biomarkers and analytical dose reconstruction. Individual characteristics of these techniques, their limitations and potential for further development are reviewed, and their usefulness in specific exposure scenarios is discussed. Whilst no single technique fulfils the criteria of an ideal dosemeter, an integrated approach using multiple techniques tailored to the exposure scenario can cover most requirements. (authors)

  12. Interstitial brachytherapy dosimetry update

    International Nuclear Information System (INIS)

    In March 2004, the American Association of Physicists in Medicine (AAPM) published an update to the AAPM Task Group No. 43 Report (TG-43) which was initially published in 1995. This update was pursued primarily due to the marked increase in permanent implantation of low-energy photon-emitting brachytherapy sources in the United States over the past decade, and clinical rationale for the need of accurate dosimetry in the implementation of interstitial brachytherapy. Additionally, there were substantial improvements in the brachytherapy dosimetry formalism, accuracy of related parameters and methods for determining these parameters. With salient background, these improvements are discussed in the context of radiation dosimetry. As an example, the impact of this update on the administered dose is assessed for the model 200 103Pd brachytherapy source. (authors)

  13. Secondary standards dosimetry laboratories

    International Nuclear Information System (INIS)

    The Secondary Standards Dosimetry Laboratory (SSDL) is part of an international network of dosimetry laboratories established by the IAEA and WHO. The network services maintain the consistency and accuracy of the therapeutic dose by exercising a national and international intercomparison program as well as providing calibration services to the end users, mainly radiotherapy departments in hospitals. The SSDL's are designated by national laboratories (such as Primary Standards Dosimetry Laboratories, PSDL's) to provide national and international absorbed dose traceability for users in that country. The advantage of the SSDL is that the absorbed dose measurements are consistent among the stakeholder countries.The Physics and Safety divisions have recently re-established an SSDL at ANSTO. The SSDL utilises a collimated cobalt-60 source of activity 170 TBq and dose rate of SmGy/sec at 1 metre (within ±2%), and provides a service to calibrate therapy level thimble ionisation chambers and electrometers

  14. Survey of international personnel radiation dosimetry programs

    International Nuclear Information System (INIS)

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

  15. Directing experimental biology: a case study in mitochondrial biogenesis.

    Directory of Open Access Journals (Sweden)

    Matthew A Hibbs

    2009-03-01

    Full Text Available Computational approaches have promised to organize collections of functional genomics data into testable predictions of gene and protein involvement in biological processes and pathways. However, few such predictions have been experimentally validated on a large scale, leaving many bioinformatic methods unproven and underutilized in the biology community. Further, it remains unclear what biological concerns should be taken into account when using computational methods to drive real-world experimental efforts. To investigate these concerns and to establish the utility of computational predictions of gene function, we experimentally tested hundreds of predictions generated from an ensemble of three complementary methods for the process of mitochondrial organization and biogenesis in Saccharomyces cerevisiae. The biological data with respect to the mitochondria are presented in a companion manuscript published in PLoS Genetics (doi:10.1371/journal.pgen.1000407. Here we analyze and explore the results of this study that are broadly applicable for computationalists applying gene function prediction techniques, including a new experimental comparison with 48 genes representing the genomic background. Our study leads to several conclusions that are important to consider when driving laboratory investigations using computational prediction approaches. While most genes in yeast are already known to participate in at least one biological process, we confirm that genes with known functions can still be strong candidates for annotation of additional gene functions. We find that different analysis techniques and different underlying data can both greatly affect the types of functional predictions produced by computational methods. This diversity allows an ensemble of techniques to substantially broaden the biological scope and breadth of predictions. We also find that performing prediction and validation steps iteratively allows us to more completely

  16. What Trends Do Turkish Biology Education Studies Indicate?

    Science.gov (United States)

    Topsakal, Unsal Umdu; Calik, Muammer; Cavus, Ragip

    2012-01-01

    The aim of this study is to determine what trends Turkish biology education studies indicate. To achieve this aim, the researchers examined online databases of the Higher Education Council and open access archives of graduate theses in web sites of Turkish universities. Finally, totally 138 graduate theses were elicited to analyze in regard to…

  17. Impact of Radiation Biology on Fundamental Insights in Biology

    Science.gov (United States)

    Setlow, Richard B.

    1982-07-27

    Research supported by OHER [Office of Health and Environmental Research] and its predecessors has as one of its major goals an understanding of the effects of radiation at low doses and dose rates on biological systems, so as to predict their effects on humans. It is not possible to measure such effects directly. They must be predicted from basic knowledge on how radiation affects cellular components such as DNA and membranes and how cells react to such changes. What is the probability of radiation producing human mutations and what are the probabilities of radiation producing cancer? The end results of such studies are radiation exposure standards for workers and for the general population. An extension of these goals is setting standards for exposure to chemicals involved in various energy technologies. This latter problem is much more difficult because chemical dosimetry is a primitive state compared to radiation dosimetry.

  18. 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

  19. Psychological and biological foundations of time preference : evidence from a day reconstruction study with biological tracking

    OpenAIRE

    Daly, Michael; Delaney, Liam; Harmon, Colm

    2008-01-01

    This paper considers the relationship between the economic concept of time preference and relevant concepts from psychology and biology. Using novel data from a time diary study conducted in Ireland that combined detailed psychometric testing with medical testing and real-time bio-tracking, we examine the distribution of a number of psychometric measures linked to the economic concept of time preferences and test the extent to which these measures form coherent clusters and the degree to whic...

  20. Status of the personnel dosimetry service of the National Institute of Radiation Hygiene in Norway, including practical experience from a Scandinavian intercomparison study

    International Nuclear Information System (INIS)

    A status report of the nationwide personnel monitoring service at the National Institute of Radiation Hygiene (SIS) in Norway is presented, together with the results from a Scandinavian intercomparison study. The personnel dosimetry service at SIS covered approx. 5,200 workers in 1983, corresponding to 70% of all occupational exposed individuals being monitored. The service covers mainly medical and industrial radiography, but also various other applications within medicine and industry. Nuclear installations are not included. The collective doses for 1983 amount to 4.7 manSv for medical occupations, and 1.1. manSv for industrial radiography. These figures include estimates of the unrecorded collective doses below the detection limit, calculated on the basis of log-probability distributions. A Scandinavian filmbadge intercomparison study was performed in spring 1984. The random uncertainty of the filmbadge measurements was below 20% for all countries, and the total uncertainty was within the factor of 2 as recommended by the ICRP. (author)

  1. Dosimetry on the radiological risks prevention in radiotherapy

    International Nuclear Information System (INIS)

    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)

  2. Neutron dosimetry characteristics of PADC manufactured by Instrument Plastics Ltd

    International Nuclear Information System (INIS)

    PADC from a UK manufacturer with no history of producing dosimetry grade material has been obtained with a view to assessing the potential for this new material being used in the HPA neutron personal dosimetry service. The HPA is always looking for alternative suppliers, both to seek out better dosimetry grade PADC, but also to secure long-term supplies for the dosimetry service. This new material has been tested in terms of its mean background, background variability and response to ascertain its dosimetric potential. The stopping of high-energy α-particles has also been studied in a stack of dosemeters to compare the LET threshold of the new material with that currently used in the personal neutron dosimetry service.

  3. 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.  

  4. Bayesian Methods for Radiation Detection and Dosimetry

    CERN Document Server

    Groer, Peter G

    2002-01-01

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

  5. Model selection for radiochromic film dosimetry

    CERN Document Server

    Méndez, Ignasi

    2015-01-01

    The purpose of this study was to find the most accurate model for radiochromic film dosimetry by comparing different channel independent perturbation models. A model selection approach based on (algorithmic) information theory was followed, and the results were validated using gamma-index analysis on a set of benchmark test cases. Several questions were addressed: (a) whether incorporating the information of the non-irradiated film, by scanning prior to irradiation, improves the results; (b) whether lateral corrections are necessary when using multichannel models; (c) whether multichannel dosimetry produces better results than single-channel dosimetry; (d) which multichannel perturbation model provides more accurate film doses. It was found that scanning prior to irradiation and applying lateral corrections improved the accuracy of the results. For some perturbation models, increasing the number of color channels did not result in more accurate film doses. Employing Truncated Normal perturbations was found to...

  6. Status of radiation processing dosimetry

    DEFF Research Database (Denmark)

    Miller, A.

    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...

  7. Report of the panel on practical problems in actinide biology

    International Nuclear Information System (INIS)

    Practical problems are classified as the need to make operational decisions, the need for regulatory assessment either of individual facilities or of generic actions, and the overt appearance of radiobiological effects in man or radioactivity in man or the environment. Topics discussed are as follows: simulated reactor accident; long term effects of low doses; effects of repeated exposures to actinides; inhaled uranium mine air contaminants; metabolism and dosimetry; environmental equilibrium models; patterns of alpha dosimetry; internal dose calculations; interfaces between actinide biology and environmental studies; removal of actinides deposited in the body; and research needs related to uranium isotopes

  8. Contribution of customised dosimetry for small animal to the treatments of cancers by metabolic radiotherapy

    International Nuclear Information System (INIS)

    This research thesis first reports a bibliographical study which addressed the use of ionizing radiations in cancer therapy (evolution from ionizing radiation to metabolic radiotherapy, biological and physical parameters, and absorbed dose in metabolic radiotherapy) and the role imagery has in customised dosimetry (absorbed dose calculation methods, determination of cumulative activity, dosimetric models for S factor calculation). Then, the author presents a software which has been specifically developed for the creation of dosimetric models, and reports its validation. He reports the comparison between different dosimetric models in the case of mice. He highlights two applications of the developed tool: radio-immunotherapy and metabolic radiotherapy. He finally proposes a general discussion on the impact of small animal dosimetry on metabolic radiotherapy

  9. Radiation dosimetry by potassium feldspar

    Indian Academy of Sciences (India)

    Arun Pandya; S G Vaijapurkar; P K Bhatnagar

    2000-04-01

    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 exposure. The annealed feldspar shows a glow peak at 120°C after gamma exposure. This peak can be used to measure gamma doses beyond 25 cGy when the TL is measured after 24 h from termination of exposure.

  10. Use of semiconductor devices in integrating dosimetry

    International Nuclear Information System (INIS)

    Radiation effects in semiconductors have been investigated with a big effort during the last years and some results of these studies are also usable for dosimetric purposes. Silicon diodes for neutron dosimetry are the best known example of such application. Nevertheless, some other devices show measurable radiation-induced changes of parameters as well and can work as integrating dosemeters. The review of potential possibilities of using such effects in dosimetry is given in the first part of this paper. Dosimetric properties of one type of optoelectronic devices, namely photo-couplers of Czechoslovak make, are discussed in the other part. (author)

  11. Practical neutron dosimetry at high energies

    International Nuclear Information System (INIS)

    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

  12. Stable isotope methods in biological and ecological studies of arthropods

    NARCIS (Netherlands)

    Hood-Nowotny, R.C.; Knols, B.G.J.

    2007-01-01

    This is an eclectic review and analysis of contemporary and promising stable isotope methodologies to study the biology and ecology of arthropods. It is augmented with literature from other disciplines, indicative of the potential for knowledge transfer. It is demonstrated that stable isotopes can b

  13. Learning Experiences of University Biology Faculty: A Qualitative Pilot Study

    Science.gov (United States)

    Kusch, Jennifer

    2016-01-01

    The study described in this article incorporates qualitative research through in-depth, individual, structured interviews with 12 biology faculty from two Midwestern universities to explore perceptions about how they have learned to teach and how they work to improve their skills.

  14. Vitamin D biology and heart failure : Clinical and experimental studies

    NARCIS (Netherlands)

    Meems, Laura

    2015-01-01

    In the last decade, vitamin D biology has been studied more extensively than ever before.. The use of vitamin D supplements is common, and so is determination of plasma vitamin D status. Besides its role in bone homeostasis, vitamin D is thought to be an important player in the development and treat

  15. Subject Didactic Studies of Research Training in Biology and Physics.

    Science.gov (United States)

    Lybeck, Leif

    1984-01-01

    The objectives and design of a 3-year study of research training and supervision in biology and physics are discussed. Scientific problems arising from work on the thesis will be a focus for the postgraduate students and their supervisors. Attention will be focused on supervisors' and students' conceptions of science, subject range, research,…

  16. Considerations for clinical pharmacology studies for biologics in emerging markets.

    Science.gov (United States)

    Damle, Bharat; White, Robert; Wang, Huifen Faye

    2015-03-01

    Registration of innovative biologics in Emerging Markets (EMs) poses many opportunities and challenges. The BRIC-MT countries (Brazil, Russia, India, China, Mexico, and Turkey) that are the fastest growing markets and regulators in these countries have imposed certain requirements, including the need for local clinical studies, for registration of biologics. The regulatory landscape in these countries is rapidly evolving, which necessitates an up-to-date understanding of such requirements. There is growing evidence which suggests that race, after accounting for body weight differences, may not influence the pharmacokinetics of biologics to the same extent that it does for small molecules. Thus, the requirements for clinical pharmacology trials in EMs are driven mainly by regulatory needs set forth by local Ministry of Health. In addition to the clinical Phase I to III studies done in the global program that supports registration in large geographies, countries such as China require local single and multiple dose Phase I studies. Participating in global studies with clinical sites within their country may be sufficient for some markets, while other regulators may be satisfied with a Certificate of Pharmaceutical Product. This paper discusses the current requirements for registration of innovative biologics in key EMs. PMID:25707959

  17. Systems Biology Approaches to Epidemiological Studies of Complex Diseases

    OpenAIRE

    Li, Hongzhe

    2013-01-01

    Systems biology approaches to epidemiological studies of complex diseases include collection of genetic, genomic, epigenomic and metagenomic data in large-scale epidemiological studies of complex phenotypes. Designs and analyses of such studies raise many statistical challenges. This paper reviews some issues related to integrative analysis of such high dimensional and inter-related data sets and outline some possible solutions. I focus my review on integrative approaches for genome-wide gene...

  18. Structural and Computational Studies of Small Organic and Biological Molecules

    OpenAIRE

    Lozano-Casal, Patricia

    2006-01-01

    Over the last three decades high-pressure X-ray diffraction techniques have been widely utilised to perform structural studies in many areas of research. For example, physicists make use of these experimental techniques to investigate metals, conductor and semi-conductor compounds among others, whereas geochemists apply them to study the conditions deep within the Earth’s interior. Furthermore, pressure studies have reached an important status in chemistry, biology and planetary science, and ...

  19. Ion storage dosimetry

    Science.gov (United States)

    Mathur, V. K.

    2001-09-01

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

  20. Individual Dosimetry Service

    CERN Multimedia

    2004-01-01

    We inform all staffs and users under regular dosimetry control that the dosimeters for the monitoring period MAY-JUNE 2004 are available from their usual dispatchers. Please have your films changed before the 11th MAY 2004. The color of the dosimeter valid in MAY-JUNE 2004 is YELLOW.