Sci—Sat AM(1): Planning — 10: Evaluation of a New Commercial Monte‐Carlo Treatment Planning System for Electrons

It has long been understood that the Monte Carlo (MC) method is the most effective means for accurately computing the dose delivered by clinical electron beams. Every commercial implementation of the MC method involves design compromises and the possibility of error. It is important, therefore, that each implementation is independently validated under conditions similar to those found in the clinic. In this abstract, we present the initial stages of validation for the XiO electron Monte Carlo (XiO eMC) software, a new treatment planning system for electron beams developed and commercialized by CMS incorporated. In this abstract we present a limited set of comparisons of calculated and experimental data for homogeneous water phantoms and for a 3D heterogeneous phantom meant to approximate the geometry of a trachea and spine. All Monte Carlo calculated and measured output factors agree within the estimated standard error for standard and extended SSD for open applicators and cerrobend cutouts with the exception of the smallest cutout size (2×2cm2) for 17 MeV at extended SSD. We also found good agreement between calculated and experimental depth dose curves and dose profiles. Dose calculations in heterogeneous phantoms are also in a very good agreement with measurements, given an estimated positional uncertainty of ±0.1cm in the depth direction, and provided that appropriate calculation voxel sizes are used for a given geometry. Acknowledgment: The authors would like to acknowledge the excellent technical support provided by Dr. J C Satterthwaite of Elekta CMS Software.