硼被认为可以通过 p   11B → 3α 核捕获反应增强布拉格峰区域质子束的生物有效性。然而，许多研究小组在体外没有观察到这种增强作用，或者最近对其提出的机制提出了质疑。为了帮助阐明这一现象，我们通过临床 190 MeV 质子束在平台或布拉格峰区域照射 DU145 前列腺癌或 U-87 MG 胶质母细胞瘤细胞，添加或不添加 10B 或 11B 同位素作为巯基十二硼酸钠 (BSH)。结果表明，11B 但不是 10B 或 BSH 分子的其他成分增强质子束对细胞的杀伤作用。这种增强选择性地发生在布拉格峰区域，硼浓度低至 40 ppm 时就会出现，并且不是由二次中子引起的。这种增强可能是由产生三个α粒子的质子-硼捕获反应引发的，这是仅在少数细胞中发生的罕见事件，并且它们的效果通过细胞间通讯放大到群体水平的反应。所研究的前列腺癌或胶质母细胞瘤细胞在硼的存在下观察到存活水平降低高达 2-3 倍，这表明这些肿瘤类型具有广阔的临床应用前景。© 2024。作者。

Boron has been suggested to enhance the biological effectiveness of proton beams in the Bragg peak region via the p + 11B → 3α nuclear capture reaction. However, a number of groups have observed no such enhancement in vitro or questioned its proposed mechanism recently. To help elucidate this phenomenon, we irradiated DU145 prostate cancer or U-87 MG glioblastoma cells by clinical 190 MeV proton beams in plateau or Bragg peak regions with or without 10B or 11B isotopes added as sodium mercaptododecaborate (BSH). The results demonstrate that 11B but not 10B or other components of the BSH molecule enhance cell killing by proton beams. The enhancement occurs selectively in the Bragg peak region, is present for boron concentrations as low as 40 ppm, and is not due to secondary neutrons. The enhancement is likely initiated by proton-boron capture reactions producing three alpha particles, which are rare events occurring in a few cells only, and their effects are amplified by intercellular communication to a population-level response. The observed up to 2-3-fold reductions in survival levels upon the presence of boron for the studied prostate cancer or glioblastoma cells suggest promising clinical applications for these tumour types.© 2024. The Author(s).