Investigating the impact of various radio-sensitizers for pencil beam scanning proton therapy

Abstract

Radiotherapy aims to deliver a concentrated radiation dose to the tumour, and several researchers have suggested using nanoparticles (NPs) as radiosensitizers to enhance dose distribution within the tumour volume. NPs function in radiation therapy by doping specific materials inside the tumour, which increases the therapeutic radiation dose within the tumour by enhancing the secondary electrons from the NPs. Specific materials such as Bismuth, Gold, Platinum, Gadolinium, Iron, and Silver can be used as radiosensitizers owing to their unique characteristics, such as higher mass-energy absorption coefficients compared with that of soft tissues, biocompatibility, and low toxicity. These can be used to improve the dose to the target without affecting the healthy tissues. This study investigated the effect of radio-sensitizing materials on proton therapy applications using the Geant4 toolkit. The simulation model involves a water phantom incorporating a sensitive target mixed with various radiosensitizers of different materials and concentrations. Twenty-four simulation models were constructed, and each model was irradiated with a pencil proton beam with kinetic energy of 70 MeV. This study aimed to assess the efficacy of radiosensitizers as radiation dose enhancers for pencil beam scanning (PBS) proton therapy.