Determination of fast neutron RBE using a fully mechanistic computational model

Azam Zabihi; John Tello; Sebastien Incerti; Ziad Francis; Ghasem Forozani; Farid Semsarha; Amir Moslehi; Mario A Bernal

doi:10.1016/j.apradiso.2019.108952

Determination of fast neutron RBE using a fully mechanistic computational model

Appl Radiat Isot. 2020 Feb:156:108952. doi: 10.1016/j.apradiso.2019.108952. Epub 2019 Nov 2.

Authors

Azam Zabihi¹, John Tello², Sebastien Incerti³, Ziad Francis⁴, Ghasem Forozani⁵, Farid Semsarha⁶, Amir Moslehi⁷, Mario A Bernal⁸

Affiliations

¹ Department of Physics, Faculty of Science, Bu-Ali Sina University, Hamedan, Iran.
² Instituto de Física Gleb Wataghin, Universidade Estadual de Campinas, Brazil.
³ University of Bordeaux, CENBG, UMR 5797, F-33170, Gradignan, France; CNRS, IN2P3, CENBG, UMR 5797, F-33170, Gradignan, France.
⁴ Université Saint Joseph, Faculty of Sciences, Department of Physics, Beirut, Lebanon.
⁵ Department of Physics, Payame Noor University, P.O. Box 19395-3697, Tehran, Iran.
⁶ Institute of Biochemistry and Biophysics (IBB), University of Tehran, P.O. Box: 13145-1384, Tehran, Iran.
⁷ Radiation Applications Research School, Nuclear Science and Technology Research Institute, P.O. Box: 11365-3486, Tehran, Iran.
⁸ Instituto de Física Gleb Wataghin, Universidade Estadual de Campinas, Brazil. Electronic address: mbernalrod@gmail.com.

PMID: 31735447
DOI: 10.1016/j.apradiso.2019.108952

Abstract

This work presents a model previously developed for estimating relative biological effectiveness (RBE) associated with high-LET particles. It is based on the combination of Monte Carlo simulations of particle interactions when traversing an atomic resolution DNA geometrical model. In addition, the model emulates the induction of lethal damage from the interaction of two sublethal lesions, taken as double-strand breaks. The Geant4-DNA package was used for simulations with liquid water as the transport medium. The RBE of neutron beams with energies ranging from 0.1 MeV up to 14 MeV was studied. The model succeeded in reproducing the general behavior of RBE as a function of neutron energy, including the RBE peak reported by experiments at approximately 0.4 MeV. Furthermore, the results of the model agree rather well with some experimental works. However, our results underestimate RBE for neutron energies above approximately 5 MeV due to the current limitations of Geant4-DNA for the tracking of heavy ions below 0.5 MeV/u.

Keywords: Monte Carlo; Neutron; RBE; Radiobiology.