Agradecimentos: We would like to acknowledge Ton Duc Thang University for giving us access to the University computing facilities. We also deeply thank the Computing Research Center, KEK, Tsukuba, Japan, for offering us computing resources for the simulations presented in this work. T. V. Nhan Hao acknowledges support by the U.S. NSF Grant No. 1415656, and U.S. DOE Grant No. DE-FG02- 08ER41533. M. A. Bernal thanks the FAPESP foundation, in Brazil, for financing his research activities through the Project 2011/51594-2 Ver menos

Abstract: Gold nanoparticles have been reported as a possible radio-sensitizer agent in radiation therapy due to their ability to increase energy deposition and subsequent direct damage to cells and DNA within their local vicinity. Moreover, this increase in energy deposition also results in an increase of the radiochemical yields. In this work we present, for the first time, an in silico investigation, based on the general purpose Monte Carlo simulation toolkit Geant4, into energy deposition and radical species production around a spherical gold nanoparticle 50 nm in diameter via proton irradiation. Simulations were preformed for incident proton energies ranging from 2 to 170 MeV, which are of interest for clinical proton therapy Ver menos