Determination of dosimetric characteristics of a new design 125I brachytherapy source with marker of Ag+Al2O3 using the monte carlo code MCNPX

The purpose of this study is to determine the dosimetric parameters of a new 125I brachytherapy seed model¡ using Monte Carlo (MC) simulations according to the TG-43U1 recommendation. The Monte Carlo simulated dosimetric parameters of this sourse have been provided with MCNPX v.2.6 code. The source contains a cylindrical Agɝ marker which is located at the center of the seed and onto which a thin layer of 125I has been uniformly adsorbed. The results of this evaluation indicate the value of the dose rate constant of 0.980 ± 0.12 cGyh−1U−1 in liquid water. The parameters of this source were determined and compared with other commercial sources models and there was an acceptable agreement between calculated dosimetric parameters of this new source and other commercial sources models and it indicates that this seed is an acceptable seed for clinical use.