Monte Carlo study of secondary electron production from gold nanoparticle in proton beam irradiation

Purpose: In this study, we examined some characteristics of secondary electrons produced by gold nanoparticle (NP) during proton beam irradiation. Method: By using the Geant4 Monte Carlo simulation toolkit, we simulated the NP at the range from radius (r) of 17.5 nm, 25 nm, 35 nm to r = 50 nm. The proton beam energies used were 20MeV, 50MeV, and 100MeV. Findings on secondary electron production and their average kinetic energy  are presented in this paper. Results: Firstly, for NP with a finite size, the secondary electron production increase with decreasing incident proton beam energy and secondary buildup existed outside NP. Secondly, the average kinetic energy of secondary electrons produced by a gold NP increased with incident proton beam energy. Thirdly, the larger the NP size, the more the secondary electron production. Conclusion: Collectively, our results suggest that apart from biological uptake efficiency, we should take the secondary electron production effect into   account when considering the potential use of NPs in proton beam irradiation. ----------------------------------------------- Cite this article as : Gao J, Zheng Y. Monte Carlo study of secondary electron production from gold nanoparticle in proton beam irradiation. Int J  Cancer Ther Oncol 2014; 2 (2):02025. DOI: http://dx.doi.org/10.14319/ijcto.0202.5