TOPAS-nBio validation for simulating water radiolysis and DNA damage under low-LET irradiation
| Autor: | Harald Paganetti, Sebastien Incerti, Bruce A. Faddegon, J A LaVerne, K Stefanová, N. Dominguez-Kondo, Václav Štěpán, J Perl, Aimee L. McNamara, José Ramos-Méndez, W-G Shin, Jan Schuemann, Carmen Villagrasa, Jamie R. Milligan, Yann Perrot |
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| Přispěvatelé: | Centre d'Etudes Nucléaires de Bordeaux Gradignan (CENBG), Université Sciences et Technologies - Bordeaux 1-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS) |
| Rok vydání: | 2021 |
| Předmět: |
Materials science
Clinical Sciences Monte Carlo method Biomedical Engineering Analytical chemistry Radiation chemistry 7. Clean energy Article Dissociation (chemistry) radiation chemistry 030218 nuclear medicine & medical imaging Reaction rate 03 medical and health sciences plasmid DNA 0302 clinical medicine Affordable and Clean Energy Ionization Linear Energy Transfer Computer Simulation Radiology Nuclear Medicine and imaging ComputingMilieux_MISCELLANEOUS validation Geant4-DNA Radiological and Ultrasound Technology Water track structure Other Physical Sciences Nuclear Medicine & Medical Imaging Chemical species 030220 oncology & carcinogenesis Yield (chemistry) Radiolysis [PHYS.PHYS.PHYS-MED-PH]Physics [physics]/Physics [physics]/Medical Physics [physics.med-ph] DNA damage TOPAS-nBio Monte Carlo Method DNA Damage |
| Zdroj: | Physics in medicine and biology, vol 66, iss 17 Phys Med Biol Physics in Medicine and Biology Physics in Medicine and Biology, IOP Publishing, 2021, 66 (17), pp.175026. ⟨10.1088/1361-6560/ac1f39⟩ |
| ISSN: | 1361-6560 0031-9155 |
| DOI: | 10.1088/1361-6560/ac1f39 |
| Popis: | 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, e(−)(aq), and H(2) with published experimental data. For H(2)O(2) and H(•), 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 (137)Cs γ-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 and H(•), 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 LET irradiation. |
| Databáze: | OpenAIRE |
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