Simulation of silver nanoparticle radio-sensitized tumor and evaluation of dose enhancement in photon therapy

Treatment of radio-sensitized tumor is one of the promising modalities in radiotherapy. Since the different parameters and physical conditions vary in the treatments, the use of simulation models is easier, less costly and faster than practical methods for forecasting the solutions designed to optimize treatment. Therefore in this study, Monte Carlo simulations are applied to investigate the dose enhancement and the influential factors in photon therapy of silver nanoparticle radio-sensitized tumor. Consideration of the exact composition and sequence of the different tissues is the main task of this article. Head phantom with its actual composition was modeled by MCNPX code. Common tumor and silver nanoparticle radio-sensitized tumor are simulated. In this study, it was assumed that nanoparticles in the tumor are distributed homogeneously. Dose Calculation and its enhancement in photon therapy were calculated. The results show improved dose in the silver nanoparticles radio-sensitized tumor. This parameter is a linear function of concentration. Although silver k edge energy is 25.53 KeV, but optimized energy is between 35 to 45 KeV. Moreover, it is concluded that dose enhancement decreases by increasing the tumor depth.