Simulation of ion-induced water radiolysis in different conditions of oxygenation

Colliaux, Anthony; Gervais, B.; Rodriguez-Lafrasse, Claire; Beuve, M.

doi:10.1016/j.nimb.2015.08.057

Cited by 24 publications

(51 citation statements)

References 23 publications

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“…Second, our model assumes that ROD and DNA damage fixation occur instantaneously once ionizing energy is deposited into the cell. In fact, these processes occur on the time scale of microseconds (Colliaux et al, 2015) and therefore the proposed model may not be entirely accurate for radiation pulses significantly shorter than 100…”

Section: Discussionmentioning

confidence: 99%

A computational model of radiolytic oxygen depletion during FLASH irradiation and its effect on the oxygen enhancement ratio

2019

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Recent results from animal irradiation studies have rekindled interest in the potential of ultra-high dose rate irradiation (also known as FLASH) for reducing normal tissue toxicity. However, despite mounting evidence of a "FLASH effect", a mechanism has yet to be elucidated. This article hypothesizes that the radioprotecting effect of FLASH irradiation could be due to the specific sparing of hypoxic stem cell niches, which have been identified in several organs including the bone marrow and the brain. To explore this hypothesis, a new computational model is presented that frames transient radiolytic oxygen depletion (ROD) during FLASH irradiation in terms of its effect on the oxygen enhancement ratio (OER). The model takes into consideration oxygen diffusion through the tissue, its consumption by metabolic cells, and its radiolytic depletion to estimate the relative decrease in radiosensitivity of cells receiving FLASH irradiation. Based on this model, several predictions are made that could be tested in future experiments: (1) the FLASH effect should gradually disappear as the radiation pulse duration is increased from <1s to 10 s; (2) dose should be deposited using the smallest number of radiation pulses to achieve the greatest FLASH effect; (3) a FLASH effect should only be observed in cells that are already hypoxic at the time of irradiation; and (4) changes in capillary oxygen tension (increase or decrease) should diminish the FLASH effect.

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Section: Discussionmentioning

confidence: 99%

A computational model of radiolytic oxygen depletion during FLASH irradiation and its effect on the oxygen enhancement ratio

2019

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“…In Figure 2, the calculated time-dependent yield of solvated electrons, produced by a proton track of 5 MeV, in a target with a partial oxygen pressure in air of 21% has been compared with different chemical track structure codes [15,31]. The initial electron yield, simulated by the TRAX-CHEM code, is higher as compared to the other simulation approaches.…”

Section: Radiolysis Of Oxygenated Watermentioning

confidence: 99%

“…These species are particularly damaging, since they are involved in the lipid peroxidation chain and play an important role in the production of other toxic species, such as hydroxyl radicals OH • through the Haber-Weiss reaction (catalyzed by the presence of transition metals), peroxynitrite ions ONOO − through the interaction with nitrogen monoxide NO • , and H 2 O 2 after scavenging by superoxide dismutase enzymes (SOD). The latter theory is supported by both theoretical approaches [11][12][13][14][15] and chemical and biological experimental observations [16][17][18][19] mainly based on studies on the Fenton reaction and on the relation with SOD.…”

Section: Introductionmentioning

confidence: 98%

Impact of Target Oxygenation on the Chemical Track Evolution of Ion and Electron Radiation

Boscolo

Krämer

Fuß

et al. 2020

IJMS

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The radiosensitivity of biological systems is strongly affected by the system oxygenation. On the nanoscopic scale and molecular level, this effect is considered to be strongly related to the indirect damage of radiation. Even though particle track radiolysis has been the object of several studies, still little is known about the nanoscopic impact of target oxygenation on the radical yields. Here we present an extension of the chemical module of the Monte Carlo particle track structure code TRAX, taking into account the presence of dissolved molecular oxygen in the target material. The impact of the target oxygenation level on the chemical track evolution and the yields of all the relevant chemical species are studied in water under different irradiation conditions: different linear energy transfer (LET) values, different oxygenation levels, and different particle types. Especially for low LET radiation, a large production of two highly toxic species ( HO 2 • and O 2 • − ), which is not produced in anoxic conditions, is predicted and quantified in oxygenated solutions. The remarkable correlation between the HO 2 • and O 2 • − production yield and the oxygen enhancement ratio observed in biological systems suggests a direct or indirect involvement of HO 2 • and O 2 • − in the oxygen sensitization effect. The results are in agreement with available experimental data and previous computational approaches. An analysis of the oxygen depletion rate in different radiation conditions is also reported. The radiosensitivity of biological systems is strongly affected by the system oxygenation. On the nanoscopic scale and molecular level, this effect is considered to be strongly related to the indirect damage of radiation. Even though particle track radiolysis has been the object of several studies, still little is known about the nanoscopic impact of target oxygenation on the radical yields. Here we present an extension of the chemical module of the Monte Carlo particle track structure code TRAX, taking into account the presence of dissolved molecular oxygen in the target material. The impact of the target oxygenation level on the chemical track evolution and the yields of all the relevant chemical species are studied in water under different irradiation conditions: different linear energy transfer (LET) values, different oxygenation levels, and different particle types. Especially for low LET radiation, a large production of two highly toxic species ( HO 2 • and O 2 • − ), which is not produced in anoxic conditions, is predicted and quantified in oxygenated solutions. The remarkable correlation between the HO 2 • and O 2 • − production yield and the oxygen enhancement ratio observed in biological systems suggests a direct or indirect involvement of HO 2 • and O 2 • − in the oxygen sensitization effect. The results are in agreement with available experimental data and previous computational approaches. An analysis of the oxygen depletion rate in different radiation conditions is also reported.

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“…Both observables, assessed via the LQD, PHYCHEML and CHEM Monte Carlo codes [13,16,17], depend on the time T RCE that separates the irradiation and the measurement of the yield of the reactive chemical species, which interact and recombine continuously with each other. The modelling of cell survival probability to global events is realized owing to a linearquadratic (LQ) expression in terms of the chemical specific energy:…”

Section: Cell Survival To Non-local Eventsmentioning

confidence: 99%

NanOx Predictions of Cell Survival Probabilities for Three Cell Lines

Monini¹,

Testa²,

Beuve³

2017

Acta Phys. Pol. B

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NanOx, a new biophysical model developed to predict cell survival probability in the context of hadrontherapy, will be presented in the following. The model takes into account the fully stochastic nature of ionizing radiation by considering dose fluctuations both at nanometric and micrometric scales, and introduces the concept of chemical specific energy. The latter represents the induction of cell death by "non-local" events as the accumulation of cellular oxidative stress or sub-lethal lesions induced by reactive chemical species. Such "non-local" events are complementary to "local" events, which take place at a very localized scale and are considered as lethal since they can singly cause cell death. NanOx predictions for V79, CHO-K1 and HSG cell lines irradiated by carbon ions are in a good agreement with the experimental data. The model is able to describe the effectiveness of ions, including the overkill effect at high LET values via the fit of a limited set of parameters. Moreover, the typical shoulder in cell survival curves is reproduced owing to the introduction of the chemical specific energy which varies with LET.

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Simulation of ion-induced water radiolysis in different conditions of oxygenation

Cited by 24 publications

References 23 publications

A computational model of radiolytic oxygen depletion during FLASH irradiation and its effect on the oxygen enhancement ratio

A computational model of radiolytic oxygen depletion during FLASH irradiation and its effect on the oxygen enhancement ratio

Impact of Target Oxygenation on the Chemical Track Evolution of Ion and Electron Radiation

NanOx Predictions of Cell Survival Probabilities for Three Cell Lines

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