Speaker
Description
Biological effects for instance DNA single-/double-strand breaks (SSB/DSB) in nanodosimetry has been estimated quantitatively in conventional Monte Carlo methods. i.e. the methods simulate track structure of charged particles and distribution of molecular species such as hydroxyl radicals inside a cell nucleus. From the overlaid distributions of energy loss and molecular species on such geometry, the positions where physical and chemical interactions occurred with DNA components can be scored. This approach allows evaluating DNA damages induced by radiation with higher accuracy, but at the costs of huge computation times.
We evaluate radiation damages induced on DNA molecules with a new clustering algorithm that uses a simple geometry. Any complex cell geometries such as DNA double-helix structures are not necessary to take into account in this algorithm. Yields of SSB/DSB are estimated by this method based on sampled positions where DNA damages occurred. We developed an application with MPEXS-DNA to estimate DNA damages using this clustering algorithm, where MPEXS-DNA is a nanodosimetry simulator based on Geant4-DNA running on GPU devices. Our application predicts yields of SSB/DSB induced by ionization of charged particles (direct yields) and chemical interactions of hydroxyl radicals (indirect yields). We compared our results with other Monte Carlo codes and measurements. In conclusion, MPEXS-DNA agreed reasonably well with them.
