Development of a model for estimating DNA lesions induced by electrons, protons and carbon ions based on track-structure simulation in the PHITS code

Matsuya, Yusuke  ; Kai, Takeshi   ; Akamatsu, Ken*; Nakano, Toshiaki*; Yoshii, Yuji*; Shikazono, Naoya*; Sato, Tatsuhiko   

Biological effects such as cell death are intrinsically related in track structure and early DNA damage induction. As such, DNA damage estimation based on Monte Carlo simulations is a research topic of worldwide interest. In this study, we developed a model for estimating DNA damage yields based on a general-purpose Monte Carlo code, Particle and Heavy Ion Transport code System (PHITS). By analyzing the spatial patterns of ionization and excitations, the model allows to predict yields of single-strand break, double-strand break and the clustered lesions for electron, proton and carbon ion. As a result, this model successfully reproduced experimental yields of various DNA lesion types in cells for low-LET radiation < about 30 keV/m. In addition, this model was also found to be sufficient for reproducing the yields measured under dry or hypoxic condition for high-LET ions. This work is expected to contribute on precise understanding of relation between track structure and biological effects.