Enhanced electron beam and X-ray beam therapy by applying nanoparticle heterojunctions: A Monte Carlo simulation

Cancer has become one of the major diseases that seriously threaten human health. In order to improve the therapeutic gain ratio (TGF) of conventional X-ray and electron beams, we studied the dose enhancement effect and secondary electrons emission of Au–Fe nanoparticle heterostructures by Monte Carlo method. Under the irradiation of 6 MeV photon and 6 MeV electron beams, the Au–Fe mixture has a dose enhancement effect. For this reason, we explored the secondary electrons production that leads to dose enhancement. For 6 MeV electron beam irradiation, Au–Fe nanoparticle heterojunctions have an higher electrons emission than Au and Fe nanoparticles. When cubic, spherical and cylindrical heterogeneous structures are considered, the electron emission of the columnar Au–Fe nanoparticles is the highest, with a maximum value of 0.00024. For 6 MV X-ray beam irradiation, Au nanoparticle and Au–Fe nanoparticle heterojunction have similar electrons emission, while Fe nanoparticle has the lowest one. When cubic, spherical and cylindrical heterogeneous structures are considered, the electron emission of the columnar Au–Fe nanoparticles is the highest, with a maximum value of 0.000118. This study contributes to improve the tumor-killing effect of conventional X-ray radiotherapy treatment and has guiding significance for the research of new nanoparticles.