Investigation of TG-43 Dosimetric Parameters for $^{192}Ir$ HDR Brachytherapy Source Using FLUKA

Abstract

Brachytherapy dose calculations have been based on the TG-43 formalism since 1995, which considers the irradiated medium to be homogeneous and made up of water. This study aims to determine the TG-43 dosimetry parameters recommended by the AAPM and the dose rate distribution for a GammaMed HDR $^{192}Ir$ source provided by Varian Medical Systems in water phantom with dimensions of $20\times 20\times 20 \;$cm$^{3}$ using the FLUKA Monte Carlo simulation. The resulting dose rate profiles were compared with data from the Eclipse TPS along the x-axis for $z = 0.5 \;$cm, $z = -0.5 \;$cm, $z = 0 \;$cm, also along the r-axis with $x = z$, Furthermore, the TG-43 dosimetric parameters were compared with the literature results, where the radial dose function was determined at radial distances ranging from 0.2 to $8 \;$cm, and the anisotropy function was determined From 0 to $10 \;$cm with a polar angle ranging from $0 {{}^{\circ }}$ to $180 {{}^{\circ }}$. Once and for all, our results show that we have a good agreement between simulation results obtained by using FLUKA and the TPS data with a small deviation observed when the radial distance decreases.