A study on the derivation of specific absorbed fraction based on reference Korean organs

In case of internal radioactive contamination caused by the inhalation, ingestion, administration or percutaneous injection of radionuclides, it is necessary to evaluate adsorbed dose resulting from radiation exposure. The evaluation for internal absorbed dose and distribution of radio nuclides is defined depending on radioactive properties of source organ, quantity of radioisotope in the organ, physical disintegration, and type of radiation or energy emitted upon radioactive decay. These principles allow us to calculate specific absorbed fraction in each internal organ and evaluate internal absorbed dose in a little easier and more convenient manner. In this study, conventional specific absorbed fraction was derived using MIRD-type phantom as mathematical one based on reference western. The specific absorbed fraction derived with MIRD-type phantom is based on the reference western, so if it is blindly applied to Koreans who typically show difference in the weight, position and configuration of internal organs from western's ones, we may fall into the error of over- or underestimation upon deriving specific absorbed fraction. Thus, in this study, we determined specific absorbed fraction in total 9 internal organs on the basis of reference Korean using the reconstruction of mathematical MIRD-type phantom and Monte Carlo method, in the assumption that source region is identical with target region