Development of the mathematical phantom of the brazilian man for internal dosimetry calculations

This work covers the theory and construction of a Mathematical Phantom of the Brazilian, to be used in internal dosimetry. To obtain this it was necessary to develop antropometric data of mass and height for Brazilian man between 20 and 40 years old. Through Monte Carlo Method, and applying the Specific Absorbed Fraction (SAF) formalism, it was possible determine the fraction internal organs such as bones, skin and total body. The results obtained from SAF are primordial in nuclear medicine and great value in the calculation of the dose received by workers exposed and in accidental cases, to a rapid evaluation of the received by a simple person. Through SAF, the references obtained for the Brazilian man, can be noted when compared to the phantom calculated by Snyder, which proposed to represent the international reference man, showed by ICRP-23 publication, that the determined SAF of the whole body does not exceed 15% between the two phantoms, agreeing with the allowed international norms error margin permitted. The differences between the two models appear, when the numbers are presented for individual organs, where the emission origin are the lungs and taken as target, the red and yellow marrows, for an energy of 10 KeV. The result obtained is that these two marrows receive 64% more absorbed fractions in the Brazilian model than in the international model. These numbers are considered trustfully because the coefficient of variation does not exceed 7%, value that in under 50%, which makes the coefficient of variation not trustfully, this is considered out of the normal distribution. Facts like these and may others, showed in this work, determine the necessity to calculate a specific mathematical model for the Brazilian man. (author). 51 refs., 40 figs., 9 tabs