Determination of the Dosimetric Characteristics of BATAN’s 125/I Source for Brachytherapy: An Experimental Study

Abstract

I brachytherapy sources with low photon energies have been widely used in treating tumors. According to American Association of Physicists in Medicine Task Group No. 43 (AAPM TG-43) recommendations, dosimetric characteristic of the new brachytherapy sources should be determined before clinical use. In this study, dosimetric characteristic of 125 I manufactured by BATAN have been determined through measurement by using Thermoluminescent Dosemeter (TLD) and gafchromic XR-QA2 film. The radial dose function measurements were performed at distances ranging from 0.5 to 10 cm from the source center. The anisotropy functions were measured at distances of 2, 3, and 5 cm from the source center for angles ranging from 0 to 90 degree in all quadrants. The results indicated that a dose rate constants measured with TLD and film are 1.05  8 % cGy.h-1 .U-1 and 1.01  8 % cGy.h-1 .U-1 , respectively. The radial dose function decreases along with the increasing distance from source and meets the 5 th order polynomial equation. The anisotropy function result shows that the anisotropy in dose distribution increases along the source axis. This measurement data are in agreement with the previous study on EGSnrc Monte Carlo result and have a similar pattern with IsoAid and GMS BT-125 commercial 125 I source.