Made available in DSpace on 2014-10-09T12:27:52Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:04:48Z (GMT). No. of bitstreams: 0 / Tese (Doutoramento) / IPEN/T / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP

Made available in DSpace on 2014-10-09T12:27:52Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:04:48Z (GMT). No. of bitstreams: 0 / Uma metodologia dosimétrica foi estabelecida, para determinação das doses recebidas em extremidades por indivíduos ocupacionalmente expostos à radiação beta, com detectores de Al2O3:C e sistema leitor microStar, da Landauer, associados à técnica de luminescência opticamente estimulada (OSL). As principais etapas do trabalho foram: caracterização do material dosimétrico Al2O3:C utilizando a técnica de OSL; estabelecimento de um método para avaliação de dose em extremidades; determinação de taxas de dose de fontes de radiação beta; aplicação do método estabelecido em um teste prático com indivíduos ocupacionalmente expostos à radiação beta durante uma simulação de procedimento de calibração de aplicadores clínicos; validação do método desenvolvido por meio de comparação das doses obtidas no teste prático pela técnica de OSL com doses obtidas pela técnica de TL. Os resultados mostram que os detectores de Al2O3:C e a técnica de OSL podem ser utilizados em monitoração individual de extremidades e radiação beta. / Tese (Doutoramento) / IPEN/T / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP

Orientador: Diana Rodrigues Pina / Resumo: A Radiologia Intervencionista (RI) é a área da medicina que proporciona as maiores exposições ocupacionais. Os valores de dose aos quais os intervencionistas são expostos são difíceis de padronizar. Nesta pesquisa apresentamos uma avaliação completa das exposições ocupacionais e determinamos a eficiência de distintos métodos de dosimetria pessoal utilizados na RI. Essa pesquisa foi abordada em 2 etapas, conforme descrito a seguir: A primeira etapa se baseou em caracterizar as exposições ocupacionais em diferentes modalidades de procedimentos de RI vascular para duas categorias de profissionais e estimar o número de procedimentos anuais que cada profissional pode realizar sem exceder os limites de dose. Foi avaliada a exposição ocupacional, através de dosimetria termoluminescente, em diferentes partes do corpo (cristalino, tireoide, tórax, abdômen, pés e mãos) de duas categorias de intervencionistas (principais e assistentes) em três modalidades diferentes de procedimentos de RI vascular. As maiores doses equivalentes foram encontradas para as mão de ambos os profissionais, podendo chegar a aproximadamente 9 mSv em um único procedimento. Algumas regiões dos profissionais em alguns procedimentos podem receber, durante o ano, níveis de doses perigosamente perto dos limites anuais. Dosímetros posicionados no tórax podem subestimar as doses para outras regiões do corpo, especialmente abdômen, extremidades e cristalinos. Na segunda etapa foram avaliadas as eficiências de 6 diferent... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Interventional Radiology (IR) is the area of medicine that provides the largest occupational exposures. The dose values to which interventionists are exposed are difficult to standardize. In this research we present a complete evaluation of occupational exposures and determine the efficiency of different personal dosimetry methods used in IR. This research was performed in 2 stages, as described below: The first step was to characterize the occupational exposures in different modalities of vascular IR procedures for two categories of professionals. We also estimated the number of annual procedures that each professional can perform without exceeding the dose limits. Occupational exposures were evaluated in different body parts (crystalline, thyroid, thorax, abdomen, feet and hands) by two interventional categories (primary and assistants) in three different modalities of vascular IR procedures. The highest equivalent doses were found for the hands of both professionals, reaching approximately 9 mSv in a single procedure. Some regions of professionals in some procedures may receive dose levels during the year dangerously close to annual limits. Dosimeters positioned in the chest may underestimate the doses to other regions of the body, especially the abdomen, extremities and crystalline. The second stage, we evaluated the efficiencies of 6 different personal dosimetry methodologies used internationally to estimate the effective dose received by interventional professionals. An... (Complete abstract click electronic access below) / Mestre

The diploma thesis on "Radiation exposure of persons working at risk of ionising radiation at the Pilsen University Hospital" is divided into two parts. The first analyses personal effective doses of the employees of the Pilsen University Hospital in 20092013, and the second focuses on measurements of secondary radiation created after the activation of collimator systems of linear accelerators. The introduction of the theoretical part discusses the history of radiology, followed by a summary of information on the sources of ionising radiation, its characteristics, properties, methods of interaction with the environment and biological effects on organisms. The chapter on radiation protection focuses on basic legislative regulations relevant to the topic. In the Czech Republic, radiation protection of people working with sources of ionising radiation is mostly based on Act No. 18/1997 Coll., on peaceful uses of nuclear energy, and Regulation of the State Office for Nuclear Safety No. 307/2002 Coll., on radiation protection. The thesis also lists dose limits and basic information about personal dosimetry, and the theoretical section is concluded with information on the methods of protecting personnel and on provided healthcare. The thesis uses as its sources primary literature, internet links, current legislation and data from the database of the State Office for Nuclear Safety on records from personal dosimeters in the analysed period. The thesis had two objectives. The first was to compare levels of exposure at the Pilsen University Hospital. The analysis involved 579 persons in total; after arranging the data into tables and dividing employees into groups by the type of tasks they perform and their job, it was possible to compare median value indicators, confirming the hypothesis that persons carrying out intervention tasks are exposed to more ionising radiation. In order to compare the development of doses over time, a double-selection t-test was performed on data from 2009 and 2013, confirming the effectiveness of anti-radiation measures adopted at the University Hospital and a reduction in the exposure of employees in this period. The second objective was to confirm or deny the hypothesis that secondary radiation created by collimator systems, while measurable, is not sufficiently large to be detected by personal dosimeters. In order to achieve this objective, measurements were carried out at the Oncology and Radiology Clinic of the Pilsen University Hospital. The first measurements tried to determine the relationship between dose and time at various levels of energy, the second compared the relationship between dose and distance from the collimator plane and the third monitored the number of exposures until the collimator plates are saturated and dose is no longer increased. All results were arranged in tables and projected in charts. The results of the research confirmed the hypothesis that secondary radiation created during the use of high-energy equipment is just below the detection limits of personal dosimeters. For this reason, it is recommended to frequently rotate personnel working with the equipment.