Department of Physics and Applied Physics, Medical Physics Program, University of Massachusetts Lowell, Lowell, MA, USA.
Department of Physics and Applied Physics, Medical Physics Program, University of Massachusetts Lowell, Lowell, MA, USA; Department of Radiation Oncology, Brigham and Women's Hospital, Dana-Farber Cancer Institute and Harvard Medical School, Boston, MA, USA.
Nanomedicine. 2017 Jul;13(5):1653-1661. doi: 10.1016/j.nano.2017.02.017. Epub 2017 Mar 8.
Gold nanoparticle (GNP) radiotherapy has recently emerged as a promising modality in cancer treatment. The use of high atomic number nanoparticles can lead to enhanced radiation dose in tumors due to low-energy leakage electrons depositing in the vicinity of the GNP. A single metric, the dose enhancement ratio has been used in the literature, often in substantial disagreement, to quantify the GNP's capacity to increase local energy deposition. This 1D approach neglects known sources of dose anisotropy and assumes that one average value is representative of the dose enhancement. Whether this assumption is correct and within what accuracy limits it could be trusted, have not been studied due to computational difficulties at the nanoscale. Using a next-generation deterministic computational method, we show that significant dose anisotropy exists which may have radiobiological consequences, and can impact the treatment outcome as well as the development of treatment planning computational methods.
金纳米颗粒（GNP）放射疗法最近作为一种有前途的癌症治疗方法出现。由于低能泄漏电子在 GNP 附近沉积，高原子数纳米颗粒的使用可以导致肿瘤内的辐射剂量增强。在文献中，经常存在大量不一致的情况，使用单一指标——剂量增强比来量化 GNP 增加局部能量沉积的能力。这种一维方法忽略了已知的剂量各向异性源，并假设一个平均值代表剂量增强。由于纳米尺度的计算困难，尚未研究这种假设是否正确以及在何种精度范围内可以信赖。使用下一代确定性计算方法，我们表明存在显著的剂量各向异性，这可能具有放射生物学后果，并可能影响治疗结果以及治疗计划计算方法的发展。
