High-atomic-number (Z) nanoparticles produce a cascade of low-energy secondary electrons and characteristic X-rays when ionized by X-ray irradiation. These secondary particles deposit their energy in the vicinity of the nanoparticles and, provided that the latter are selectively accumulated within tumor cells, this results in increased DNA damage and tumor cell deaths. This study reviews the utilization of high-Z nanoparticles in the treatment of soft tissue sarcomas (STS). Both in vitro and in vivo experiments demonstrated that the dose is enhanced by approximately 1.2 when polyethelyne glycol (PEG)-modified gold nanoparticles, and from 1.4 to 1.8 when hafnium oxide nanoparticles (NBTXR3, Nanobiotix SA, France) are introduced into tumor cells and activated by X-ray beams. In a phase 2/3 clinical trial investigating the therapeutic benefit of using nanoparticles in preoperative external beam radiotherapy for locally advanced STS, the proportion of patients with a pathological complete response in their resected tumor was doubled when NBTXR3 nanoparticles were used. Additionally, a higher percentage of patients with complete tumor resection was observed in the NBTXR3 plus radiotherapy group. Similar toxicity profiles were found for both the NBTXR3 plus radiotherapy and the radiotherapy alone patient groups. The incorporation of radio-sensitizing nanoparticles in the preoperative radiotherapy of STS could enhance treatment outcomes.
高原子序数纳米粒子在X射线照射下电离时，会产生一系列低能次级电子和特征X射线。这些次级粒子将其能量沉积在纳米粒子附近，若纳米粒子能选择性富集于肿瘤细胞内，将导致DNA损伤加剧和肿瘤细胞死亡。本研究综述了高原子序数纳米粒子在软组织肉瘤治疗中的应用。体外和体内实验均表明：当聚乙二醇修饰的金纳米粒子进入肿瘤细胞并经X射线激活后，剂量增强因子约为1.2；而氧化铪纳米粒子（NBTXR3，法国Nanobiotix SA公司）的剂量增强因子可达1.4至1.8。在一项针对局部晚期软组织肉瘤术前外照射放疗中应用纳米粒子的2/3期临床试验中，使用NBTXR3纳米粒子的患者组其切除肿瘤达到病理完全缓解的比例翻倍。此外，NBTXR3联合放疗组中实现肿瘤完全切除的患者比例更高。NBTXR3联合放疗组与单纯放疗组患者的毒性反应谱相似。在软组织肉瘤术前放疗中引入放射增敏纳米粒子有望提升治疗效果。
肿瘤(癌症)患者之家