Department of Environmental & Radiological Health Sciences, Colorado State University, USA.
Institute for Quantum Science, National Institutes for Quantum Science and Technology, Japan.
Biochem Biophys Res Commun. 2024 Feb 12;696:149500. doi: 10.1016/j.bbrc.2024.149500. Epub 2024 Jan 9.
Carbon ion radiotherapy (CIRT) is a heavy ion charge particle therapy with 29 years of prominent use. Despite advantages like high relative biological effectiveness (RBE), improved quality of life, and reduced treatment time, challenges persist, especially regarding heavy nuclear fragments. Our research addresses these challenges in horizontal irradiation, aiming to comprehend Monoenergetic and Spread-Out Bragg peak (SOBP) carbon ion beam trajectories using cell survival analysis and visualizing biological effects through DNA damage (γ-H2AX). This reveals repair-related protein foci near the Bragg peak. CR-39, a plastic nuclear track detector, was explored to understand high-linear energy transfer (LET) tracks and radiation quality near the Bragg peak. Findings unveil high-LET DNA damage signatures through aligned γ-H2AX foci, correlating with LET values in SOBP. CR-39 visualized high-LET particle exposure, indicating comet-type etch-pits at the Bragg peak and suggesting carbon ion fragmentation. Unexpectedly, dot-type etch-pits in irradiated and post-Bragg peak regions indicated high-LET neutron production. This investigation highlights the intricate interplay of carbon ion beams, stressing the importance of understanding LET variations, DNA damage patterns, and undesired secondary exposure.
碳离子放射治疗（CIRT）是一种重离子电荷粒子治疗方法，已有 29 年的突出应用。尽管具有相对生物学效应高（RBE）、提高生活质量和减少治疗时间等优势，但仍存在挑战，特别是对于重核碎片。我们的研究解决了水平照射中的这些挑战，旨在通过细胞存活分析和通过 DNA 损伤（γ-H2AX）可视化生物效应来理解单能和扩展布喇格峰（SOBP）碳离子束轨迹。这揭示了在布拉格峰附近与修复相关的蛋白质焦点。我们探索了塑料核径迹探测器（CR-39），以了解布拉格峰附近的高线性能量转移（LET）轨迹和辐射质量。研究结果通过对齐的γ-H2AX 焦点揭示了高 LET DNA 损伤特征，与 SOBP 中的 LET 值相关。CR-39 可视化了高 LET 粒子暴露情况，表明布拉格峰处存在彗星型腐蚀坑，并提示碳离子碎裂。出乎意料的是，辐照后和布拉格峰区域的点状腐蚀坑表明产生了高 LET 中子。这项研究强调了碳离子束的复杂相互作用，强调了理解 LET 变化、DNA 损伤模式和不必要的二次暴露的重要性。
