COMPARATIVE DOSIMETRIC ASSESSMENT OF AMBULATORY AND INPATIENT IODINE-131 THERAPY USING MONTE CARLO SIMULATIONS

This study presents a regulatory and dosimetric comparison of Three iodine 131 treatment scenarios, involving the administration of 200, 3700 and 7400 MBq for scenarios A, B, and C, respectively. Monte Carlo modeling using an ICRP male phantom was employed to assess dose distribution across tissues and organs. International radiation protection guidelines were applied according to the specific scenarios. Dose comparisons across the scenarios reveal a trend proportional to the administered activity. Occupational exposures and doses received by healthcare staff measured at a distance of 1 meter from the patient, were evaluated against ICRP and IAEA discharge criteria, resulting in dose rates of 7.64, 140, and 280 uSv/h for scenarios A, B, and C, respectively. The results confirm the safety and feasibility of outpatient treatment for activities of around 786 MBq corresponding to 30 uSv/h at 1 meter, under controlled exposure conditions, whereas the administration of higher activities necessitates hospitalization in isolation due to cumulative exposure considerations.