RESUMO
In the frame of the EU Coordination Action CONRAD (coordinated network for radiation dosimetry), WP4 was dedicated to work on computational dosimetry with an action entitled 'Uncertainty assessment in computational dosimetry: an intercomparison of approaches'. Participants attempted one or more of eight problems. This paper presents the results from problems 4-8-dealing with the overall uncertainty budget estimate; a short overview of each problem is presented together with a discussion of the most significant results and conclusions. The scope of the problems discussed here are: the study of a (137)Cs calibration irradiator; the manganese bath technique; the iron sphere experiment using neutron time-of-flight technique; the energy response of a RADFET detector and finally the sensitivity and uncertainty analysis for the recoil-proton telescope discussed in the companion paper.
Assuntos
Elétrons , Nêutrons , Fótons , Dosagem Radioterapêutica , Radioterapia Assistida por Computador , Incerteza , Algoritmos , Radioisótopos de Césio/química , Humanos , Manganês/química , Radiometria/instrumentação , Radioterapia Assistida por Computador/instrumentaçãoRESUMO
Whole-body counters (WBCs) are used for the assessment of the internal contamination of actinides in the human body. WBCs require adequate calibration procedures that rely on the use of suitable calibration phantoms. A previous study carried out at the ENEA-Radiation Protection Institute was aimed at designing a head calibration phantom in which a heterogeneous distribution of 241Am point sources could satisfactorily approximate an assumed homogeneous contamination throughout the head bones. Suitable correction factors for the WBC detection efficiencies were evaluated with Monte Carlo. The present paper summarises the main aspects and implications of an advanced modelling technique based on a VOXEL approach. The methodology could be extended to other bone-seeker radionuclides.
Assuntos
Amerício/análise , Cabeça/fisiologia , Modelos Biológicos , Método de Monte Carlo , Proteção Radiológica/métodos , Radiometria/métodos , Crânio/fisiologia , Elementos da Série Actinoide/análise , Elementos da Série Actinoide/farmacocinética , Amerício/farmacocinética , Simulação por Computador , Cabeça/diagnóstico por imagem , Humanos , Modelos Estatísticos , Imagens de Fantasmas , Radiografia , Radioisótopos/análise , Radioisótopos/farmacocinética , Medição de Risco/métodos , Fatores de Risco , Espalhamento de Radiação , Crânio/diagnóstico por imagemRESUMO
The need of organ absorbed dose evaluation for radiation protection purposes stimulated, since the late 1960s, the development of anthropoid models to be used with radiation transport codes. Very significant improvements were introduced during the years, passing from stylised analytical human models to realistic voxel models based on computed tomography scans or MRI scans, and finally to advanced surface-geometry models. Besides illustrating the main contributions in this field from various international laboratories, this paper illustrates some applications of voxel models to internal (including in vivo monitoring) and external dosimetry for radiation protection.