Calculation of microdosimetric spectra for protons using Geant4-DNA and a μ-randomness sampling algorithm for the nanometric structures.

Using Geant4-DNA to account for the stochastic nature of energy depositions due to physical interactions between radiation and matter, we calculated microdosimetry parameters concerning proton irradiation. By employing microdosimetry concepts in conjunction with simulation results of our previous work on radiation effects on the DNA, we pinpointed and quantified correlations between microdosimetry parameters and DNA damage. As such, for a volume with comparable mass and mean chord length to the DNA, we could observe the clear correspondence of the mean lineal and specific energy results with the double-strand-break yields of protons in Gy-1.Gbp-1.