محاسبات دزیمتری و مقایسه توزیع دز در اطراف دو مدل چشمه ید 125 در براکی تراپی

Brachytherapy is a therapeutic approach in which radioactive sources are used to irradiate malignant tumors from near distance. In this study, the comparison of dose distribution in iodine-125 source, STM 1251 and Oncoseed 6711 models was performed using the Monte Carlo Geant4 code. The results obtained from the Monte Carlo calculations have been compared with the TG43U1 formulation and also with the available experimental results. According to the TG43U1 formula, the dose distribution of the STM 1251 has a greater influence than Oncoseed 6711. Also, this trend was observed in the region near the phantom surface that was not balanced with radiation distribution conditions. In this region, there was no significant difference between TG43U1 protocol and experimental values ​​and calculated results in this study. Therefore, the selection of the source model can be done based on the results of the Geant4 code.