New technique for effective dose estimation using Monte Carlo simulation for the patients undergoing radioiodine therapy

We presume that radioiodine capsule, used for therapy, stays in stomach for 15 min before the absorption starts when large amount of radioactivity needlessly expose a part of stomach and several surrounding organs. Investigations were performed at Institute of Pathophysiology and Nuclear Medicine, Faculty of Medicine, Ss. Cyril and Methodius University, Skopje, Macedonia. Eighty-seven patients were reviewed, age between 21 and 73. Patients were divided in 20 groups receiving average dose per group from 1813 MBq to 6105 MBq. We used Monte Carlo MCNP 4b code and gave the results only for administrated activity of 6105 MBq. Calculated results are given for imparted energy per transformation, dose equivalent and effective doses for different organs. The effective doses were between 9.17 nSv (for bone surface) to 122.4 mSv (for stomach). As the total dose is estimated to be 126.73 mSv it is obvious that the highest part is received by stomach. (C) 2012 Elsevier Ltd. All rights reserved.