Abstract

Purpose

In this work, we set out to provide an experimental setup, using Cs-131, with associated dosimetry for studying relative biological effectiveness (RBE) of Auger emitters.

Material and methods

Cs-131 decays by 100% electron capture producing K- (9%) and L- (80%) Auger electrons with mean energies of 26 keV and 3.5 keV, respectively, plus ≈ 9.4 very low energy electrons (<0.5 keV) per decay. Cs-131 accumulates in the cells through the Na⁺/K⁺-ATPase. By this uptake mechanism and the alkali chemistry of Cs⁺, we argue for its intracellular homogeneous distribution. Cs-131 was added to the cell culture medium of HeLa and V79 Cells. The bio-kinetics of Cs-131 (uptake, release, intracellular distribution) was examined by measuring its intracellular activity concentration over time. Taking advantage of the 100% confluent cellular monolayer, we developed a new and robust dosimetry that is entrusted to a quantity called S_C-value.

Results

The S_C-values evaluated in the cell nucleus are almost independent of the nuclear size and geometry. We obtained dose-rate controlled RBE-values for intracellular Cs-131 decay. Using the γH2AX assay, the RBE was 1 for HeLa cells. Using the clonogenic cell survival, it was 3.9 for HeLa cells and 3.2 for V79 cells.

Conclusion

This experimental setup and dosimetry provides reliable RBE-values for Auger emitters in various cell lines.

中文翻译：

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Cs-131 作为体外研究和量化细胞内俄歇衰变放射毒性的实验工具

摘要

目的

在这项工作中，我们着手提供一个使用 Cs-131 的实验装置，以及相关的剂量测定，用于研究俄歇发射器的相对生物有效性 (RBE)。

材料与方法

Cs-131 通过 100% 电子捕获衰变，产生平均能量分别为 26 keV 和 3.5 keV 的 K- (9%) 和 L- (80%) 俄歇电子，外加≈ 9.4 个极低能量电子 (<0.5 keV)衰变。^{Cs-131 通过 Na +} /K ⁺ -ATPase在细胞中积累。^{通过这种吸收机制和 Cs +}的碱性化学，我们支持其在细胞内的均匀分布。将 Cs-131 添加到 HeLa 和 V79 细胞的细胞培养基中。通过随时间测量其细胞内活性浓度来检查 Cs-131 的生物动力学（摄取、释放、细胞内分布）。利用 100% 汇合的细胞单层，我们开发了一种新的强大的剂量测定法，它被委托给一个叫做S _C的量-价值。

结果

在细胞核中评估的S _C值几乎与核大小和几何形状无关。我们获得了细胞内 Cs-131 衰变的剂量率控制 RBE 值。使用 γH2AX 测定，HeLa 细胞的 RBE 为 1。使用克隆细胞存活率，HeLa 细胞为 3.9，V79 细胞为 3.2。

结论

该实验设置和剂量测定为各种细胞系中的俄歇发射器提供了可靠的 RBE 值。