早期使用靶向放射性核素治疗 (TRT) 来根除播散性肿瘤细胞 (DTC) 可能会提供治愈方法。需要选择适当的放射性核素。这项工作强调了 103Pd (T1/2 = 16.991 d) 的电势，它衰减到 103mRh (T1/2 = 56.12 min)，然后通过俄歇电子和转换电子的发射达到稳定的 103Rh。方法：使用蒙特卡罗轨迹结构代码 CELLDOSE 评估单细胞（直径 14 μm；细胞核 10 μm）和 19 个细胞簇的吸收剂量。放射性核素分布在细胞表面、细胞质内或细胞核内。能量归一化后比较 103Pd、177Lu 和 161Tb 的吸收剂量。研究了非均匀细胞靶向的影响以及双重靶向的潜在益处。如果直接使用，则提供与 103mRh 相关的其他结果。结果：在单细胞中，根据放射性核素的分布，103Pd 的核吸收剂量比 177Lu 高 7 至 10 倍，膜剂量高 9 至 25 倍。在19细胞簇中，103Pd吸收剂量也大大超过177Lu。在这两种情况下，161Tb 都介于 103Pd 和 177Lu 之间。考虑到簇内有四个未标记的细胞，非均匀靶向导致中度至重度剂量异质性。例如，对于核内 103Pd，未标记的细胞仅接受了预期核剂量的 14%。使用两种 103Pd 标记的放射性药物进行靶向可最大限度地减少剂量异质性。结论：103Pd 是新一代俄歇发射器，可以向单个肿瘤细胞和细胞簇输送比 177Lu 高得多的吸收剂量。这可能为 TRT 在辅助或新辅助环境中的使用或针对微小残留病的使用开辟新的视野。© 作者。

Early use of targeted radionuclide therapy (TRT) to eradicate disseminated tumor cells (DTCs) might offer cure. Selection of appropriate radionuclides is required. This work highlights the potential of 103Pd (T1/2 = 16.991 d) which decays to 103mRh (T1/2 = 56.12 min) then to stable 103Rh with emission of Auger and conversion electrons. Methods: The Monte Carlo track structure code CELLDOSE was used to assess absorbed doses in single cells (14-μm diameter; 10-μm nucleus) and clusters of 19 cells. The radionuclide was distributed on the cell surface, within the cytoplasm, or in the nucleus. Absorbed doses from 103Pd, 177Lu and 161Tb were compared after energy normalization. The impact of non-uniform cell targeting, and the potential benefit from dual-targeting was investigated. Additional results related to 103mRh, if used directly, are provided. Results: In the single cell, and depending on radionuclide distribution, 103Pd delivered 7- to 10-fold higher nuclear absorbed dose and 9- to 25-fold higher membrane dose than 177Lu. In the 19-cell clusters, 103Pd absorbed doses also largely exceeded 177Lu. In both situations, 161Tb stood in-between 103Pd and 177Lu. Non-uniform targeting, considering four unlabeled cells within the cluster, resulted in moderate-to-severe dose heterogeneity. For example, with intranuclear 103Pd, unlabeled cells received only 14% of the expected nuclear dose. Targeting with two 103Pd-labeled radiopharmaceuticals minimized dose heterogeneity. Conclusion: 103Pd, a next-generation Auger emitter, can deliver substantially higher absorbed doses than 177Lu to single tumor cells and cell clusters. This may open new horizons for the use of TRT in adjuvant or neoadjuvant settings, or for targeting minimal residual disease.© The author(s).