In silico radiobiology: Have we reached the limit of Monte Carlo simulations?

17th International Conference on the Use of Computers in Radiation Therapy

物理学;计算机科学

Gholami, Y.^1 ; Toghyani, M.^1 ; Champion, C.^2 ; Kuncic, Z.^1

Institute of Medical Physics, School of Physics, University of Sydney, Sydney, NSW, Australia^1

Universite Bordeaux 1, CNRS/IN2P3, Centre d'Etudes Nucleaires de Bordeaux Gradignan, France^2

关键词: Atomic cross sections;    Electron charge distribution;    Hybrid Monte Carlo;    Inter-molecular bonding;    Molecular dynamics simulations;    Radiation transport;    Theoretical methods;    Very low energy electrons;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/489/1/012011/pdf
DOI  :  10.1088/1742-6596/489/1/012011

学科分类：计算机科学（综合）

来源: IOP

【 摘 要 】

Monte Carlo radiation transport models are increasingly being used to simulate biological damage. However, such radiation biophysics simulations require realistic molecular models for water, whereas existing Monte Carlo models are limited by their use of atomic cross-sections, which become inadequate for accurately modelling interactions of the very low-energy electrons that are responsible for biological damage. In this study, we borrow theoretical methods commonly employed in molecular dynamics simulations to model the molecular wavefunction of the water molecule as the first step towards deriving new molecular cross-sections. We calculate electron charge distributions for molecular water and find non-negligible differences between the vapor and liquid phases that can be attributed to intermolecular bonding in the condensed phase. We propose that a hybrid Monte Carlo-Molecular Dynamics (MC-MD) approach to modelling radiation biophysics will provide new insights into radiation damage and new opportunities to develop targeted molecular therapy strategies.