标题： 乳腺组织中金纳米颗粒（AuNPs）的蒙特卡罗模拟和剂量分析 显示英文标题

标题： Monte Carlo Simulation and Dosimetric Analysis of Gold Nanoparticles (AuNPs) in Breast Tissue

摘要： 精确的辐射递送对于有效的放射治疗至关重要，金纳米颗粒（AuNPs）已成为一种有前景的工具，可以在增强局部剂量沉积的同时保护周围的健康组织。 在这项研究中，使用了 PENELOPE 蒙特卡罗代码来研究不同条件和模型下 AuNPs 的剂量学。 在水中和具有球形形状的乳腺组织中研究了剂量增强比（DER），并与之前发表的结果一致。 为了进一步分析 AuNP 周围粒子的物理相互作用，在 AuNPs 周围的体积内创建了一个相空间文件（PSF）。 这表明较大的 AuNPs 导致剂量增加，如预期的那样，产生了超过 100 倍的 DER 值。 最后，结果显示，在 AuNP 周围的体积内，80% 的发射电子源自光电效应吸收，导致了详细的奥格尔电子发射级联分析。 还可以建立次级粒子数量与粒子体积之间的直接关系。 使用局部效应模型（LEM）确定了不同尺寸 AuNPs 在不同金浓度下的存活曲线。 本工作的最后一部分涉及分析扁平化细胞中的 AuNPs 分布，这是集落测定法中典型的细胞，观察到剂量的对数正态分布。 这促使开发了一种新的、机械论的局部效应模型，如果进一步验证，该模型可以在体外和计算机模拟中有更多应用。 显示英文摘要

摘要： Precise radiation delivery is critical for effective radiotherapy, and gold nanoparticles (AuNPs) have emerged as promising tools to enhance local dose deposition while sparing the surrounding healthy tissue. In this study, the PENELOPE Monte Carlo code was used to investigate the dosimetry of AuNPs under different conditions and models. The Dose Enhancement Ratio (DER) was studied in water and breast tissue with spherical shapes and in agreement with previously published results. To further analyse the physical interactions of the particles around the AuNP, a Phase Space File (PSF) in a volume around the AuNPs was created. This showed that larger AuNPs lead to increased doses, as expected, yielding DER values exceeding 100 times. Finally, results reveal that in the volume surrounding the AuNP, 80% of emitted electrons originate from photoelectric absorption, leading to Auger electron emission cascades which were analysed in detail. It was also possible to establish a direct relation between number of secondaries and the particle volumes. The Local Effect Model (LEM) was used to determine survival curves in AuNPs of different sizes at different gold concentrations. The last part of this work consisted in analysing a distribution of AuNPs within a flattened cell typical of clonogenic assays where a log-normal distribution of dose was observed. This led to the development of a new, mechanistic, Local Effect Model which, if further validated, can have further applications in-vitro and in-silico.