Target fragmentation in protontherapy

In protontherapy, secondary particles are produced through primary beam interactions with the patients body. The fragments are created in the inelastic interaction of the beam with the target nuclei and have low kinetic energies and/or high atomic numbers as compared to primary protons. Secondary particles produce an altered dose distribution, due to a different range of fragments and have high LET, that lead to an increase of RBE for the same delivered dose. The inclusion of target fragmentation processes is important for the accurate calculation of the treatment plan. In this study, Monte Carlo simulations were employed to estimate the effect of target fragmentation in proton therapy. In particular, the range distribution of secondary particles has been evaluated using the FLUKA code. For the evaluation of the impact of target fragmentation, the fluence of secondary particles has been calculated with simulation at different depths