Application of Monte Carlo calculations for validation of a treatment planning system in high dose rate brachytherapy

Abstract

Aim The accuracy of treatment planning systems is of vital importance in treatment outcomes in brachytherapy. In the current study the accuracy of dose calculations of a high dose rate (HDR) brachytherapy treatment planning system (TPS) was validated using the Monte Carlo method. Materials and methods Three 60Co sources of the GZP6 afterloading brachytherapy system were modelled using MCNP4C Monte Carlo (MC) code. The dose distribution around all the sources was calculated by MC and a dedicated treatment planning system. The results of both methods were compared. Results There was good agreement (<2%) between TPS and MC calculated dose distributions except at a point near the sources (<1 cm) and beyond the tip of the sources. Conclusions Our study confirmed the accuracy of TPS calculated dose distributions for clinical use in HDR brachytherapy.