Quantitative estimation of track segment yields of water radiolysis species under heavy ions around Bragg peak energies using Geant4-DNA

Kentaro Baba; Tamon Kusumoto; Shogo Okada; Ryo Ogawara; Satoshi Kodaira; Quentin Raffy; Rémi Barillon; Nicolas Ludwig; Catherine Galindo; Philippe Peaupardin; Masayori Ishikawa

doi:10.1038/s41598-021-81215-6

Quantitative estimation of track segment yields of water radiolysis species under heavy ions around Bragg peak energies using Geant4-DNA

Sci Rep. 2021 Jan 15;11(1):1524. doi: 10.1038/s41598-021-81215-6.

Authors

Affiliations

¹ Graduate School of Biomedical Science and Engineering, Hokkaido University, Kita-15 Nishi-7, Kita-ku, Sapporo, Hokkaido, 060-8638, Japan.
² National Institutes for Quantum and Radiological Science and Technology, 4-9-1 Anagawa, Inage-ku, Chiba, 263-8555, Japan.
³ High Energy Accelerator Research Organization (KEK), 1-1, Oho, Tsukuba, Ibaraki, 305-0801, Japan.
⁴ Advanced Research Center for Beam Science, Institute for Chemical Research, Kyoto University, Gokasho, Uji, Kyoto, 611-0011, Japan.
⁵ Institute Pluridisiplinaire Hubert Curien, UMR 7178, CNRS, 23 rue du Loess, 67037, Strasbourg, France.
⁶ Graduate School of Biomedical Science and Engineering, Hokkaido University, Kita-15 Nishi-7, Kita-ku, Sapporo, Hokkaido, 060-8638, Japan. masayori@med.hokudai.ac.jp.
⁷ Faculty of Health Sciences, Hokkaido University, Kita-12 Nishi-5, Kita-ku, Sapporo, Hokkaido, 060-0812, Japan. masayori@med.hokudai.ac.jp.

Abstract

We evaluate the track segment yield G' of typical water radiolysis products (e_aq^-, ^·OH and H₂O₂) under heavy ions (He, C and Fe ions) using a Monte Carlo simulation code in the Geant4-DNA. Furthermore, we reproduce experimental results of ^·OH of He and C ions around the Bragg peak energies (< 6 MeV/u). In the relatively high energy region (e.g., > 10 MeV/u), the simulation results using Geant4-DNA have agreed with experimental results. However, the G-values of water radiolysis species have not been properly evaluated around the Bragg peak energies, at which high ionizing density can be expected. Around the Bragg peak energy, dense continuous secondary products are generated, so that it is necessary to simulate the radical-radical reaction more accurately. To do so, we added the role of secondary products formed by irradiation. Consequently, our simulation results are in good agreement with experimental results and previous simulations not only in the high-energy region but also around the Bragg peak. Several future issues are also discussed regarding the roles of fragmentation and multi-ionization to realize more realistic simulations.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Computer Simulation
DNA / chemistry
Electrons
Heavy Ion Radiotherapy / methods*
Heavy Ions
Hydrogen Peroxide / chemistry*
Linear Energy Transfer / physiology
Models, Chemical
Monte Carlo Method
Physical Phenomena
Water / chemistry*

Substances

Water
DNA
Hydrogen Peroxide