Made available in DSpace on 2014-10-09T12:25:49Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:03:33Z (GMT). No. of bitstreams: 1 11316.pdf: 4559706 bytes, checksum: 49490bf32ac2f606f4a79e8d49abe990 (MD5) / Dissertacao (Mestrado) / IPEN/D / Intituto de Pesquisas Energeticas e Nucleares, IPEN/CNEN-SP

Made available in DSpace on 2014-10-09T12:45:54Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:05:35Z (GMT). No. of bitstreams: 1 07312.pdf: 3603508 bytes, checksum: 963e59f9eb3fb8b6959c554770d86544 (MD5) / Dissertacao (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP

Large-scale radiological accidents have resulted in intakes of radioactive materials by members of the public and occupational radiation workers. However, current methods to evaluate intakes are designed for small numbers of individuals and cannot be easily scaled for large populations as has occurred. A proposed method for high throughput volumes of people to identify and quantify intakes of radioactive material through urine radiobioassay is described. MATERIALS AND METHODS: The MCNP V6.0 software code was used to model the General Electric Hawkeye V3 Gamma Camera for gamma ray efficiency. Technitium-99m was used to validate the model. The model was used to calculate detection efficiencies and minimum detectable doses for Cobalt-60, Iodine-131, Cesium-137/Barium-137m and Iridium-192. RESULTS: Differences of 8% were observed between measurements of the detection efficiency for Technitium-99m and the MCNP modeled detection efficiency (11.1% vs. 12.0%, respectively). Calculations showed that a dose of 20 mSv could be detected using urine radiobioassay in 6, 3, 2, and 20 days post incident for Type F intakes of Cobalt-60, Iodine-131, Cesium-137/Barium-137m and Iridium-192 respectively. Approximately 1,152 urine samples could be analyzed in an eight-hour shift using a single gamma camera. CONCLUSIONS: The use of the gamma camera for urine radiobioassay allows for high throughput volumes of samples and has sufficient detection sensitivity to meet dose-based decision guidelines.

Made available in DSpace on 2014-10-09T12:43:21Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T13:58:04Z (GMT). No. of bitstreams: 1 06428.pdf: 6304808 bytes, checksum: 564076d766d1209b8ce5d2f96ff4876b (MD5) / Tese (Doutoramento) / IPEN/T / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP

Made available in DSpace on 2014-10-09T12:37:34Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:03:32Z (GMT). No. of bitstreams: 1 05177.pdf: 1071515 bytes, checksum: 549d323670762fe6597fcda6cf7ea4fc (MD5) / Tese (Doutoramento) / IPEN/T / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP

Made available in DSpace on 2014-10-09T12:43:21Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T13:58:04Z (GMT). No. of bitstreams: 1 06428.pdf: 6304808 bytes, checksum: 564076d766d1209b8ce5d2f96ff4876b (MD5) / Tese (Doutoramento) / IPEN/T / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP

Made available in DSpace on 2014-10-09T12:37:34Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:03:32Z (GMT). No. of bitstreams: 1 05177.pdf: 1071515 bytes, checksum: 549d323670762fe6597fcda6cf7ea4fc (MD5) / Tese (Doutoramento) / IPEN/T / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP

Made available in DSpace on 2014-10-09T12:49:19Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:01:17Z (GMT). No. of bitstreams: 1 09672.pdf: 6449551 bytes, checksum: fc741e642f1069dc9671f312a9c4532b (MD5) / Tese (Doutoramento) / IPEN/T / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP

Made available in DSpace on 2014-10-09T12:49:19Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:01:17Z (GMT). No. of bitstreams: 1 09672.pdf: 6449551 bytes, checksum: fc741e642f1069dc9671f312a9c4532b (MD5) / Tese (Doutoramento) / IPEN/T / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP

The aim of this work is to introduce a couple of new exposure scenariosof interest when personnel, family members and general public are externally irradiated from patients treated with Iodine-131. A series of modied ORNL matematical phantoms were used in Monte-Carlo simulations in PENELOPE-2011 to determine dose rates to: a cab driver where thepatient sits in the back seat at opposite side, a newborn child held by an adult patient, a doctor giving treatment to a patient while leaning over the hospital bed and collective effective dose to bus passengers if the patient travels home by bus. The cost to order taxi instead of a public transport ticket for the patient is put in relation to the lowered collective effective dose to general public and compared with other companies price per lowered manSv. Dose rate measurements and the effective half-life of I-131 are used to determine the retained whole body activity at different times post administration. This in combination with the simulations are used to estimate effective doses to the cab driver, bus passengers, newborn and personnel. Whole body-, abdominal- and thyroid source distributions were considered in the patients during simulations. Dose rates within 99.7 % condence intervals were up to: 23.7 ± 0.4, 62.7 ± 0.3, 530 ± 71, 96.8 ± 0.5 µSv/h/GBq, for the cab driver, closest bus passenger, newborn and physician respectively. Collective effective dose to bus passengers is estimated to 291 ± 2 µmanSv/h/GBq. A patient specic tool for estimating more reasonable restriction times on how long to avoid small children is developed, taking into account retained body activity and the home situation for the patient. Effective dose estimations suggest that dose constraints are very unlikely exceeded for the taxi driver, and public transport should be a considered option for thyrotoxicosis patients of lower administered activities and some cancer patients. It is also estimated that hospitals in Sweden are paying 7.6 - 31 MSEK per lowered collective effective dose of 1 manSv by sending patients by taxi instead of bus.