Applications of Monte Carlo simulation (8). Radiotherapy region. Part 2. Applications in the radiotherapy region: with a focus on charged particles

This paper introduces the application cases of Monte Carlo (MC) simulation to the radiotherapy region related to charged particles. It explains the simulation tool kit, Geant4, as an MC calculation code and the physical processes related to ion beam radiotherapy, and introduces the particle therapy simulation (PTSIM) framework as the application of Geant4. As an application example of the MC calculation system using PTSIM in proton therapy facilities, it explains the MC calculation simulation of beam modeling in the commissioning of the treatment planning equipment for the spot scanning irradiation of proton beam therapy. On the other hand, as an application example to the quality control of therapy and quality assurance of each patient, MC calculation is used to verify dose distribution and output factors that have been calculated in therapy planning equipment. In the preparation of beam input date for improving the dose calculation accuracy of therapy planning equipment, and in the dose calculation in inhomogeneous field including intra-patient, MC method is used for the improvement of treatment quality and safety to compensate the measurement and for the reduction in work load. (A.O.)