Spatial Optimization of Fractionated Proton Therapy via Mathematical Modeling

One of the methods for increasing the radiotheraphy efficiency while retaining the probability of emergence of side effects at an acceptable level is optimization of the spatial distribution of irradiation. Proton therapy has a weighty advantage over photon therapy due to a distinct energy release peak before particle stop (Bragg peak). At that, the tumor volume itself in practice is irradiated uniformly. However, a growing tumor has a nonuniform volume distribution of tumor cells which also feature nonuniform radiosensitivity. These facts can be used to optimize the spatial distribution of irradiation within a tumor to increase the number of killed tumor cells, hence, to increase chances of tumor cure while retaining normal tissue damage at a set acceptable level. In this study, using numerical simulations, the potential of such spatial optimization is demonstrated and its practical application aspects are discussed.