Independent reaction times method in Geant4-DNA: Implementation and performance
The result's identifiers
Result code in IS VaVaI
<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61389005%3A_____%2F20%3A00534258" target="_blank" >RIV/61389005:_____/20:00534258 - isvavai.cz</a>
Result on the web
<a href="https://doi.org/10.1002/mp.14490" target="_blank" >https://doi.org/10.1002/mp.14490</a>
DOI - Digital Object Identifier
<a href="http://dx.doi.org/10.1002/mp.14490" target="_blank" >10.1002/mp.14490</a>
Alternative languages
Result language
angličtina
Original language name
Independent reaction times method in Geant4-DNA: Implementation and performance
Original language description
Purpose The simulation of individual particle tracks and the chemical stage following water radiolysis in biological tissue is an effective means of improving our knowledge of the physico-chemical contribution to the biological effect of ionizing radiation. However, the step-by-step simulation of the reaction kinetics of radiolytic species is the most time-consuming task in Monte Carlo track-structure simulations, with long simulation times that are an impediment to research. In this work, we present the implementation of the independent reaction times (IRT) method in Geant4-DNA Monte Carlo toolkit to improve the computational efficiency of calculating G-values, defined as the number of chemical species created or lost per 100 eV of deposited energy. Methods The computational efficiency of IRT, as implemented, is compared to that from available Geant4-DNA step-by-step simulations for electrons, protons and alpha particles covering a wide range of linear energy transfer (LET). The accuracy of both methods is verified using published measured data from fast electron irradiations for(center dot)OH andeaq-for time-dependent G-values. For IRT, simulations in the presence of scavengers irradiated by cobalt-60 gamma-ray and 2 MeV protons are compared with measured data for different scavenging capacities. In addition, a qualitative assessment comparing measured LET-dependent G-values with Geant4-DNA calculations in pure liquid water is presented. Results The IRT improved the computational efficiency by three orders of magnitude relative to the step-by-step method while differences in G-values by 3.9% at 1 mu s were found. At 7 ps,(OH)-O-center dot andeaq-yields calculated with IRT differed from recent published measured data by 5% +/- 4% and 2% +/- 4%, respectively. At 1 mu s, differences were 9% +/- 5% and 6% +/- 7% for(center dot)OH andeaq-, respectively. Uncertainties are one standard deviation. Finally, G-values at different scavenging capacities and LET-dependent G-values reproduced the behavior of measurements for all radiation qualities. Conclusion The comprehensive validation of the Geant4-DNA capabilities to accurately simulate the chemistry following water radiolysis is an ongoing work. The implementation presented in this work is a necessary step to facilitate performing such a task.
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
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Continuities
I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace
Others
Publication year
2020
Confidentiality
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů
Data specific for result type
Name of the periodical
Medical Physics
ISSN
0094-2405
e-ISSN
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Volume of the periodical
47
Issue of the periodical within the volume
11
Country of publishing house
US - UNITED STATES
Number of pages
12
Pages from-to
5919-5930
UT code for WoS article
000577437100001
EID of the result in the Scopus database
2-s2.0-85092574861