TOPAS-nBio validation for simulating water radiolysis and DNA damage under low-LET irradiation
The result's identifiers
Result code in IS VaVaI
<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61389005%3A_____%2F21%3A00545621" target="_blank" >RIV/61389005:_____/21:00545621 - isvavai.cz</a>
Result on the web
<a href="https://doi.org/10.1088/1361-6560/ac1f39" target="_blank" >https://doi.org/10.1088/1361-6560/ac1f39</a>
DOI - Digital Object Identifier
<a href="http://dx.doi.org/10.1088/1361-6560/ac1f39" target="_blank" >10.1088/1361-6560/ac1f39</a>
Alternative languages
Result language
angličtina
Original language name
TOPAS-nBio validation for simulating water radiolysis and DNA damage under low-LET irradiation
Original language description
The chemical stage of the Monte Carlo track-structure simulation code Geant4-DNA has been revised and validated. The root-mean-square (RMS) empirical parameter that dictates the displacement of water molecules after an ionization and excitation event in Geant4-DNA has been shortened to better fit experimental data. The pre-defined dissociation channels and branching ratios were not modified, but the reaction rate coefficients for simulating the chemical stage of water radiolysis were updated. The evaluation of Geant4-DNA was accomplished with TOPAS-nBio. For that, we compared predicted time-dependent G values in pure liquid water for (OH)-O-center dot, e(-) (aq), and H-2 with published experimental data. For H2O2 and H-center dot, simulation of added scavengers at different concentrations resulted in better agreement with measurements. In addition, DNA geometry information was integrated with chemistry simulation in TOPAS-nBio to realize reactions between radiolytic chemical species and DNA. This was used in the estimation of the yield of single-strand breaks (SSB) induced by Cs-137 gamma-ray radiolysis of supercoiled pUC18 plasmids dissolved in aerated solutions containing DMSO. The efficiency of SSB induction by reaction between radiolytic species and DNA used in the simulation was chosen to provide the best agreement with published measurements. An RMS displacement of 1.24 nm provided agreement with measured data within experimental uncertainties for time-dependent G values and under the presence of scavengers. SSB efficiencies of 24% and 0.5% for (OH)-O-center dot and H-center dot, respectively, led to an overall agreement of TOPAS-nBio results within experimental uncertainties. The efficiencies obtained agreed with values obtained with published non-homogeneous kinetic model and step-by-step Monte Carlo simulations but disagreed by 12% with published direct measurements. Improvement of the spatial resolution of the DNA damage model might mitigate such disagreement. In conclusion, with these improvements, Geant4-DNA/TOPAS-nBio provides a fast, accurate, and user-friendly tool for simulating DNA damage under low linear energy transfer irradiation.
Czech name
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Czech description
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Classification
Type
J<sub>imp</sub> - Article in a specialist periodical, which is included in the Web of Science database
CEP classification
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OECD FORD branch
30224 - Radiology, nuclear medicine and medical imaging
Result continuities
Project
<a href="/en/project/GJ17-03403Y" target="_blank" >GJ17-03403Y: Links between radiation track structure and clustered DNA damage</a><br>
Continuities
I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace
Others
Publication year
2021
Confidentiality
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů
Data specific for result type
Name of the periodical
Physics in Medicine and Biology
ISSN
0031-9155
e-ISSN
1361-6560
Volume of the periodical
66
Issue of the periodical within the volume
17
Country of publishing house
GB - UNITED KINGDOM
Number of pages
12
Pages from-to
175026
UT code for WoS article
000692240200001
EID of the result in the Scopus database
2-s2.0-85114499351