Sung Wonmo, Jung Seongmoon, Ye Sung-Joon
Department of Transdisciplinary Studies, Program in Biomedical Radiation Sciences, Seoul National University Graduate School of Convergence Science and Technology, Seoul, Korea. Biomedical Research Institute, Seoul National University College of Medicine, Seoul, Korea.
Phys Med Biol. 2016 Nov 7;61(21):7522-7535. doi: 10.1088/0031-9155/61/21/7522. Epub 2016 Oct 7.
The aim of this study is to investigate the dosimetric characteristics of nanoparticle-enhanced Auger therapy. Monte Carlo (MC) simulations were performed to assess electron energy spectra and dose enhancement distributions around a nanoparticle. In the simulations, two types of nanoparticle structures were considered: nanoshell and nanosphere, both of which were assumed to be made of one of five elements (Fe, Ag, Gd, Au, and Pt) in various sizes (2-100 nm). Auger-electron emitting radionuclides (I-125, In-111, and Tc-99m) were simulated within a nanoshell or on the surface of a nanosphere. For the most promising combination of Au and I-125, the maximum dose enhancement was up to 1.3 and 3.6 for the nanoshell and the nanosphere, respectively. The dose enhancement regions were restricted within 20-100 nm and 0-30 nm distances from the surface of Au nanoshell and nanosphere, respectively. The dose enhancement distributions varied with sizes of nanoparticles, nano-elements, and radionuclides and thus should be carefully taken into account for biological modeling. If the nanoparticles are accumulated in close proximity to the biological target, this new type of treatment can deliver an enhanced microscopic dose to the target (e.g. DNA). Therefore, we conclude that Auger therapy combined with nanoparticles could have the potential to provide a better therapeutic effect than conventional Auger therapy alone.
本研究的目的是调查纳米颗粒增强俄歇治疗的剂量学特征。进行了蒙特卡罗（MC）模拟，以评估纳米颗粒周围的电子能谱和剂量增强分布。在模拟中，考虑了两种类型的纳米颗粒结构：纳米壳和纳米球，假定它们由五种元素（铁、银、钆、金和铂）中的一种制成，尺寸各异（2 - 100纳米）。俄歇电子发射放射性核素（碘 - 125、铟 - 111和锝 - 99m）在纳米壳内或纳米球表面进行了模拟。对于金和碘 - 125最有前景的组合，纳米壳和纳米球的最大剂量增强分别高达1.3和3.6。剂量增强区域分别限制在距金纳米壳和纳米球表面20 - 100纳米和0 - 30纳米的距离内。剂量增强分布随纳米颗粒尺寸、纳米元素和放射性核素而变化，因此在生物建模时应仔细考虑。如果纳米颗粒在生物靶标附近积累，这种新型治疗可以向靶标（如DNA）传递增强的微观剂量。因此，我们得出结论，与单独的传统俄歇治疗相比，纳米颗粒联合俄歇治疗可能有潜力提供更好的治疗效果。
