Developing a new Monte Carlo algorithm as an alternative tool to simulate virtual source model on an Elekta Versa HD Linac

The aim of this study is to develop in-house Monte Carlo (MC) algorithm as an alternative tool to simulate all mechanisms of interactions for dose calculation in radiation therapy. Additionally, evaluating the MC-SCAN algorithm with beam modeling of Elekta VersaHD Linac was aimed. Mohan 6 MV photon spectrum was used and the source was modeled as a point source. The absorbed dose is calculated via modeling all interaction mechanisms to gain energy deposition. TPR20/10, PDD, photon profile of different field sizes as well as point dose was calculated after that, a comparison of all the achieved results with experimental measurements went through. The difference between calculated mean energy and theoretical one was obtained <1%. The calculated TPR20/10 value was (0.685 ± 0.03). The difference between experimental PDD and photon profile, and the calculated ones by new model was <3% for all field sizes. A new MC algorithm can be used as an alternative tool to simulate virtual source model on an Elekta VersaHD Linac. All calculated values turned out to present the difference between experimental measurements to be <3% for homogeneous mediums. Nonetheless, further research was needed to be done for the better improvement.