Intercomparison of nanodosimetric distributions in nitrogen simulated with Geant4 and PTra track structure codes

Pietrzak, Marcin; Nettelbeck, Heidi; Perrot, Y.; Villagrasa, C.; Bancer, Aleksandr; Bug, Marion U.; Incerti, S.

doi:10.1016/j.ejmp.2022.09.003

Cited by 6 publications

(2 citation statements)

References 36 publications

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“…Because of the high water content in most biological systems, it is common practice to assume that energy deposition, and ionization, in liquid water is a satisfactory approximation to energy deposition, and ionization, in the biological system of interest. It is very difficult to validate the physics models adopted in track structure Monte Carlo codes against experimental data in liquid water due to the lack of experimental methods to measure physical quantities describing particle track structure in water at the nanometric scale (Incerti et al , 2010b; Pietrzak et al , 2022). Total and differential cross-sections adopted in track structure Monte Carlo codes can be compared qualitatively to experimental measurements performed in water vapor, within the gas-phase approximation.…”

Section: Monte Carlo Simulations For Microdosimetrymentioning

confidence: 99%

ICRU Report 98, Stochastic Nature of Radiation Interactions: Microdosimetry

Braby,

Conte,

Dingfelder

et al. 2023

J�ICRU

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The Journal of the ICRU publishes reports on important and topical subjects within the field of radiation science and measurement. It is the successor to the series of reports published by or on behalf of the International Commission on Radiation Units and Measurements (ICRU) since 1927. The Commission continually reviews radiation science with the aim of identifying areas where the development of guidance and recommendations can make an important contribution.

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Section: Monte Carlo Simulations For Microdosimetrymentioning

confidence: 99%

ICRU Report 98, Stochastic Nature of Radiation Interactions: Microdosimetry

Braby,

Conte,

Dingfelder

et al. 2023

J�ICRU

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“…Geant4-DNA, an extension of the general-purpose Monte Carlo code Geant4 (Agostinelli et al 2003), is an MCTS code with a modular design that permits the incorporation of new cross-sections without the need to change a significant portion of the already existing code. Today, Geant4-DNA has models that allow the simulation of interaction processes for photons, electrons, protons, and all charged states of alpha particles among other particles for transport in mediums consisting of liquid water, gold (Sakata et al 2018), nucleotides (Zein et al 2023) and nitrogen (Pietrzak et al 2022). The low energy limit for the different models of Geant4-DNA is about 10 eV for electrons (depending on the models), 100 eV for protons and for bare alpha particles (Incerti et al 2010b, Bernal et al 2015.…”

Section: Introductionmentioning

confidence: 99%

Lithium inelastic cross-sections and their impact on micro and nano dosimetry of boron neutron capture

D-Kondo,

Ortiz,

Faddegon

et al. 2024

Phys. Med. Biol.

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Objective: To present a new set of lithium-ion cross-sections for (i) ionization and excitation processes down to 700 eV, and (ii) charge-exchange processes down to 1 keV/u. To evaluate the impact of the use of these cross-sections on micro a nano dosimetric quantities in the context of boron neutron capture (BNC) applications/techniques.Approach: The Classical Trajectory Monte Carlo (CTMC) method was used to calculate Li ion charge-exchange cross sections in the energy range of 1 keV/u to 10 MeV/u. Partial Li ion charge states ionization and excitation cross-sections were calculated using a detailed charge screening factor. The cross-sections were implemented in Geant4-DNA v10.07 and simulations and verified using TOPAS-nBio by calculating stopping power and CSDA range against data from ICRU and SRIM. Further microdosimetric and nanodosimetric calculations were performed to quantify differences against other simulation approaches for low energy Li ions. These calculations were: lineal energy spectra (yf(y) and yd(y)), frequency mean lineal energy (y_F ) ̅, dose mean lineal energy (y_D ) ̅ and ionization cluster size distribution analysis. Microdosimetric calculations were compared against a previous MC study that neglected charge-exchange and excitation processes. Nanodosimetric results were compared against pure ionization scaled cross-sections calculations.Main Results: Calculated stopping power differences between ICRU and Geant4-DNA decreased from 33.78% to 6.9%. The CSDA range difference decreased from 621% to 34% when compared against SRIM calculations. Geant4-DNA/TOPAS calculated dose mean lineal energy differed by 128% from the previous Monte Carlo. Ionization cluster size frequency distributions for Li ions differed by 76% to 344.11% for 21 keV and 2 MeV respectively. With a decrease in the N1 within 9% at 10 keV and agreeing after the 100 keV. With the new set of cross-sections being able to better simulate low energy behaviors of Li ions.Significance: This work shows an increase in detail gained from the use of a more complete set of low energy cross-sections which include charge exchange processes. Significant differences to previous simulation results were found at the microdosimetric and nanodosimetric scales that suggest that Li ions cause less ionizations per path length traveled but with more energy deposits. Microdosimetry results suggest that the BNC’s contribution to cellular death may be mainly due to alpha particle production when boron-based drugs are distributed in the cellular membrane and beyond and by Li when it is at the cell cytoplasm regions.

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