Boron neutron capture therapy (BNCT) is an anticancer modality realized through ¹⁰B accumulation in tumor cells, neutron irradiation of the tumor, and decay of boron atoms with the release of alpha-particles and lithium nuclei that damage tumor cell DNA. As high-LET particle release takes place inside tumor cells absorbed dose calculations are difficult, since no essential extracellular energy is emitted. We placed gold nanoparticles inside tumor cells saturated with boron to more accurately measure the absorbed dose. T98G cells accumulated ~50 nm gold nanoparticles (AuNPs, 50 µg gold/mL) and boron-phenylalanine (BPA, 10, 20, 40 µg boron-10/mL), and were irradiated with a neutron flux of 3 × 10⁸ cm⁻²s⁻¹. Gamma-rays (411 keV) emitted by AuNPs in the cells were measured by a spectrometer and the absorbed dose was calculated using the formula D = (k × N × n)/m, where D was the absorbed dose (GyE), k—depth-related irradiation coefficient, N—number of activated gold atoms, n—boron concentration (ppm), and m—the mass of gold (g). Cell survival curves were fit to the linear-quadratic (LQ) model. We found no influence from the presence of the AuNPs on BNCT efficiency. Our approach will lead to further development of combined boron and high-Z element-containing compounds, and to further adaptation of isotope scanning for BNCT dosimetry.

中文翻译：

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金纳米颗粒允许在硼中子俘获治疗恶性肿瘤中进行原位吸收剂量评估

硼中子俘获疗法 (BNCT) 是一种抗癌方式，通过¹⁰ B 在肿瘤细胞中的积累、肿瘤的中子照射以及硼原子的衰变以及破坏肿瘤细胞 DNA 的 α 粒子和锂核的释放来实现。由于高LET粒子释放发生在肿瘤细胞内，因此吸收剂量的计算很困难，因为没有必要的细胞外能量被释放。我们将金纳米粒子放置在用硼饱和的肿瘤细胞内，以更准确地测量吸收剂量。T98G 细胞积累了约 50 nm 金纳米粒子（AuNPs，50 µg 金/mL）和硼苯丙氨酸（BPA，10、20、40 µg 硼-10/mL），并用 3 × 10 ⁸ cm的中子通量进行辐照⁻²秒⁻¹. 用光谱仪测量细胞中 AuNPs 发射的伽马射线 (411 keV)，并使用公式D = ( k × N × n )/ m计算吸收剂量，其中D是吸收剂量 (GyE)，k ——深度相关辐照系数，N ——活化金原子数，n ——硼浓度 (ppm)，和m——黄金的质量（g）。细胞存活曲线符合线性二次 (LQ) 模型。我们发现 AuNP 的存在对 BNCT 效率没有影响。我们的方法将导致进一步开发含硼和高 Z 元素的化合物，并进一步适应同位素扫描以进行 BNCT 剂量测定。