A New Study of Bragg Curve of the 12C Ion at Energies Ranging 200–400 MeV/u with the Contribution of Secondary Fragments in Hadrontherapy Using the PHITS Monte Carlo Code

Due to the Bragg peak’s (BP) shown ballistic accuracy and increasing relative biological effectiveness (RBE) at the end of the course, hadron therapy promises to significantly improve radiation therapy. As a result, tumors that are challenging to treat, incompletely resected, or radiation-resistant are specially treated with hadron therapy. The energy loss is predominantly driven by inelastic electron collision mechanisms in the energy range used in charged particle treatment (60 to 450 MeV/u). However, in several cases, nuclear collisions contribute to the generation of fragments. These fragments present a significant disadvantage for medical applications as they deposit energy that reduces the quality of the Bragg peak (BP), particularly in its tail, leading to unnecessary dose to healthy tissue behind the target. The purpose of this research is to assess, via Monte-Carlo simulation, the contribution to the dose of secondary particles created during the interaction of a 12C ion beam in a water phantom using the Particle and Heavy Ion Transport Code System (PHITS) code. First, the code was validated by comparing the simulation output to an experimental result derived from NSRL data. The second step was to assess the depth dose from the 12C ion beam as well as the contribution of primary and secondary particles to the overall dose in a water phantom. Finally, a thorough simulation of the contribution of fragments from a 400 MeV/u carbon ion beam was carried out. The results of these distributions are of great interest for considering the effect of fragments in carbon therapy.