Abstract

Purpose

This paper aims to investigate how the spatial distribution of boron in cells and oxygen concentration affect the DNA damage induced by charged particles in boron neutron capture therapy (BNCT) by Monte Carlo simulations, and further to evaluate the relative biological effectiveness (RBE) of DNA double-strand breaks (DSBs) induction.

Materials and methods

The kinetic energy spectra of α, ⁷Li particles in BNCT arriving at the nucleus surface were obtained from GEANT4 (Geant4 10.05.p01). The DNA damage caused by BNCT was then evaluated using MCDS (MCDS 3.10A).

Results

When α or ⁷Li particles were distributed in the cytomembrane or cytoplasm, the difference in DNA damage of the same types was less than 0.5%. Taking the 137Cs photons as the reference radiation, when the oxygen concentration varied from 0% to 50%, the RBE of 0.54MeV protons and recoil protons varied from 5 to 2, whereas it decreased from 10 to 3 for α or ⁷Li particles.

Conclusion

The RBE of DSB induction all charged particles in BNCT decreased with the increase of oxygen concentration. This work indicated that the RBE of different radiation particles of BNCT might be affected by many factors, which should be paid attention to in theoretical research or clinical application.

中文翻译：

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硼和氧浓度的空间分布对硼中子俘获疗法诱导的 DNA 损伤的影响使用蒙特卡罗模拟

摘要

目的

本文旨在通过蒙特卡罗模拟研究硼在细胞中的空间分布和氧浓度如何影响硼中子俘获疗法 (BNCT) 中带电粒子诱导的 DNA 损伤，并进一步评估 DNA 的相对生物有效性 (RBE)。双链断裂（DSBs）诱导。

材料和方法

BNCT中α, ⁷ Li 粒子到达原子核表面的动能谱是从 GEANT4 (Geant4 10.05.p01) 获得的。然后使用 MCDS (MCDS 3.10A) 评估由 BNCT 引起的 DNA 损伤。

结果

当α或⁷ Li粒子分布在细胞膜或细胞质中时，相同类型的DNA损伤差异小于0.5%。以 137Cs 光子为参考辐射，当氧浓度从 0% 变化到 50% 时，0.54MeV 质子和反冲质子的 RBE 从 5 变化到 2，而对于 α 或⁷ Li 粒子，RBE 从 10 减少到 3 。

结论

DSB诱导BNCT中所有带电粒子的RBE随着氧浓度的增加而降低。该工作表明BNCT不同辐射粒子的RBE可能受多种因素的影响，在理论研究或临床应用中应予以重视。