Modeling of scavenging systems in water radiolysis with Geant4-DNA.
Details
Serval ID
serval:BIB_20E04D5FEE89
Type
Article: article from journal or magazin.
Collection
Publications
Institution
Title
Modeling of scavenging systems in water radiolysis with Geant4-DNA.
Journal
Physica medica
ISSN
1724-191X (Electronic)
ISSN-L
1120-1797
Publication state
Published
Issued date
04/2023
Peer-reviewed
Oui
Volume
108
Pages
102549
Language
english
Notes
Publication types: Journal Article
Publication Status: ppublish
Publication Status: ppublish
Abstract
This paper presents the capabilities of the Geant4-DNA Monte Carlo toolkit to simulate water radiolysis with scavengers using the step-by-step (SBS) or the independent reaction times (IRT) methods. It features two examples of application areas: (1) computing the escape yield of H <sub>2</sub> O <sub>2</sub> following a <sup>60</sup> Co γ-irradiation and (2) computing the oxygen depletion in water irradiated with 1 MeV electrons.
To ease the implementation of the chemical stage in Geant4-DNA, we developed a user interface that helps define the chemical reactions and set the concentration of scavengers. The first application area example required two computational steps to perform water radiolysis using NO <sub>2</sub> <sup>-</sup> and NO <sub>3</sub> <sup>-</sup> as scavengers and a <sup>60</sup> Co irradiation. The oxygen depletion computation technique for the second application area example consisted of simulating track segments of 1 MeV electrons and determining the radio-induced loss and gain of oxygen molecules.
The production of H <sub>2</sub> O <sub>2</sub> under variable scavenging levels is consistent with the literature; the mean relative difference between the SBS and IRT methods is 7.2 % ± 0.5 %. For the oxygen depletion 1 µs post-irradiation, the mean relative difference between both methods is equal to 9.8 % ± 0.3 %. The results in the microsecond scale depend on the initial partial pressure of oxygen in water. In addition, the computed oxygen depletions agree well with the literature.
The Geant4-DNA toolkit makes it possible to simulate water radiolysis in the presence of scavengers. This feature offers perspectives in radiobiology, with the possibility of simulating cell-relevant scavenging mechanisms.
To ease the implementation of the chemical stage in Geant4-DNA, we developed a user interface that helps define the chemical reactions and set the concentration of scavengers. The first application area example required two computational steps to perform water radiolysis using NO <sub>2</sub> <sup>-</sup> and NO <sub>3</sub> <sup>-</sup> as scavengers and a <sup>60</sup> Co irradiation. The oxygen depletion computation technique for the second application area example consisted of simulating track segments of 1 MeV electrons and determining the radio-induced loss and gain of oxygen molecules.
The production of H <sub>2</sub> O <sub>2</sub> under variable scavenging levels is consistent with the literature; the mean relative difference between the SBS and IRT methods is 7.2 % ± 0.5 %. For the oxygen depletion 1 µs post-irradiation, the mean relative difference between both methods is equal to 9.8 % ± 0.3 %. The results in the microsecond scale depend on the initial partial pressure of oxygen in water. In addition, the computed oxygen depletions agree well with the literature.
The Geant4-DNA toolkit makes it possible to simulate water radiolysis in the presence of scavengers. This feature offers perspectives in radiobiology, with the possibility of simulating cell-relevant scavenging mechanisms.
Keywords
Water/chemistry, Hydrogen Peroxide, Radiobiology/methods, DNA/chemistry, Monte Carlo Method, Computer Simulation, FLASH effect, Geant4-DNA, Scavenger, Water radiolysis
Pubmed
Web of science
Open Access
Yes
Create date
20/03/2023 10:08
Last modification date
18/11/2023 7:08