Estimation of tumour dose enhancement due to gold nanoparticles during typical radiation treatments: a preliminary Monte Carlo study
Estimation of tumour dose enhancement due to gold nanoparticles during typical radiation treatments: a preliminary Monte Carlo study
复制标题
DOI：
10.1088/0031-9155/50/15/n01
复制
发表时间：
2005-08-07
影响因子：
3.5
通讯作者：
Cho, SH
中科院分区：
文献类型：
--
作者：
Cho, SH
最近一项小鼠研究表明，金纳米粒子可以安全使用，并用于在放射治疗期间提高肿瘤剂量。由于金的原子序数较高，且纳米粒子更容易穿透肿瘤血管，金纳米粒子的使用似乎比早期方法更有前景。然而，到目前为止，因使用金纳米粒子而可能产生的剂量增强尚未得到很好的量化，特别是对于常见的放射治疗情况。因此，当前的初步研究通过蒙特卡罗计算，对几个代表以下几种放射治疗模式的体模测试案例估计了这种剂量增强：140 kVp X射线、4和6 MV光子束以及Ir - 192伽马射线。当前研究考虑了肿瘤内三种金浓度水平，其中两种基于上述小鼠研究，并假设肿瘤外无金或只有一种金浓度水平。在假设肿瘤外无金且可达到7mg金/克肿瘤的金浓度的情况下，140 kVp X射线案例中考虑的肿瘤体积内的剂量增强至少可达2倍。基于相同假设，4和6 MV光子束案例中的肿瘤剂量增强范围从约1%到7%，这取决于肿瘤内的金含量和光子束的品质。对于Ir - 192案例，肿瘤区域内的剂量增强范围从5%到31%，取决于肿瘤内的径向距离和金浓度水平。对于7mg金/克肿瘤的案例，当周围正常组织中的金含量为2mg金/克时，正常组织剂量会增加，140 kVp X射线、6 MV光子束和Ir - 192伽马射线分别增加高达30%、可忽略不计和约2%，而肿瘤内剂量增强的幅度基本不变。
A recent mice study demonstrated that gold nanoparticles could be safely administered and used to enhance the tumour dose during radiation therapy. The use of gold nanoparticles seems more promising than earlier methods because of the high atomic number of gold and because nanoparticles can more easily penetrate the tumour vasculature. However, to date, possible dose enhancement due to the use of gold nanoparticles has not been well quantified, especially for common radiation treatment situations. Therefore, the current preliminary study estimated this dose enhancement by Monte Carlo calculations for several phantom test cases representing radiation treatments with the following modalities: 140 kVp x-rays, 4 and 6 MV photon beams, and Ir-192 gamma rays. The current study considered three levels of gold concentration within the tumour, two of which are based on the aforementioned mice study, and assumed either no gold or a single gold concentration level outside the tumour. The dose enhancement over the tumour volume considered for the 140 kVp x-ray case can be at least a factor of 2 at an achievable gold concentration of 7 mg Au/g tumour assuming no gold outside the tumour. The tumour dose enhancement for the cases involving the 4 and 6 MV photon beams based on the same assumption ranged from about 1% to 7%, depending on the amount of gold within the tumour and photon beam qualities. For the Ir-192 cases, the dose enhancement within the tumour region ranged from 5% to 31%, depending on radial distance and gold concentration level within the tumour. For the 7 mg Au/g tumour cases, the loading of gold into surrounding normal tissue at 2 mg Au/g resulted in an increase in the normal tissue dose, up to 30%, negligible, and about 2% for the 140 kVp x-rays, 6 MV photon beam, and Ir-192 gamma rays, respectively, while the magnitude of dose enhancement within the tumour was essentially unchanged.