Quantifying the initial damage induction is necessary to understand the dependence of the late effects on radiation quality. This study was conducted to better understand the effects of therapeutic radionuclides on human cells and to improve the therapeutic efficacy of TRT. In this study, early direct and indirect DNA damage induced by four widely used therapeutic radionuclides (Y-90, I-131, Lu-177, and I-125) in human fibroblasts was investigated using Geant4 DNA. The relative effects of direct and indirect damage induction on DNA and human cells were evaluated using complexity and source classification. In addition, we performed an analysis of the histogram of fragment length distribution for therapeutic radionuclides. The results of this study showed that the highest single-strand break (SSB) and double-strand break (DSB) yields based on source classification are due to the relative effects of indirect damage induction on DNA and human cells. Radionuclide I-131 has the highest yield of SSB, while I-125 has the highest yield of DSB. On the other hand, Y-90 has the lowest SSB and DSB yield values. The study also revealed that I-125 has the highest fragment length distribution, while Y-90 has the lowest. Among the therapeutic radionuclides, I-131 and I-125 had the greatest effect on SSB and DSB yield values, respectively, while Y-90 had little effect.

中文翻译：

---

使用 Geant4-DNA 评估四种治疗性放射性核素对人成纤维细胞诱导的早期 DNA 损伤

量化初始损伤感应对于了解后期效应对辐射质量的依赖性是必要的。本研究旨在更好地了解治疗性放射性核素对人体细胞的影响并提高 TRT 的治疗效果。在本研究中，使用 Geant4 DNA 研究了四种广泛使用的治疗性放射性核素（Y-90、I-131、Lu-177 和 I-125）在人成纤维细胞中诱导的早期直接和间接 DNA 损伤。使用复杂性和来源分类来评估直接和间接损伤诱导对 DNA 和人类细胞的相对影响。此外，我们还对治疗性放射性核素的碎片长度分布的直方图进行了分析。这项研究的结果表明，基于来源分类的最高单链断裂 (SSB) 和双链断裂 (DSB) 产量是由于间接损伤诱导对 DNA 和人类细胞的相对影响。放射性核素 I-131 的 SSB 产率最高，而 I-125 的 DSB 产率最高。另一方面，Y-90 具有最低的 SSB 和 DSB 屈服值。研究还表明，I-125 的片段长度分布最高，而 Y-90 的片段长度分布最低。在治疗放射性核素中，I-131和I-125分别对SSB和DSB产值影响最大，而Y-90影响不大。