（99m）Tc 与（188）Re 经细胞内摄取后，钠碘同向转运体（NIS）阳性细胞的集落形成能力降低。

Reduction in clonogenic survival of sodium-iodide symporter (NIS)-positive cells following intracellular uptake of (99m)Tc versus (188)Re.

机构信息

University Hospital/Faculty of Medicine Carl Gustav Carus, Technische Universität Dresden, Department of Nuclear Medicine, Dresden, Germany.

出版信息

Int J Radiat Biol. 2012 Dec;88(12):991-7. doi: 10.3109/09553002.2012.728303. Epub 2012 Oct 9.

DOI:10.3109/09553002.2012.728303

PMID:22967084

Abstract

PURPOSE

Cellular radionuclide uptake increases the heterogeneity of absorbed dose to biological structures. Dose increase depends on uptake yield and emission characteristics of radioisotopes. We used an in vitro model to compare the impact of cellular uptake of (188)Re-perrhenate and (99m)Tc-pertechnetate on cellular survival.

MATERIALS AND METHODS

Rat thyroid PC Cl3 cells in culture were incubated with (188)Re or (99m)Tc in the presence or absence of perchlorate for 1 hour. Clonogenic cell survival was measured by colony formation. In addition, intracellular radionuclide uptake was quantified.

RESULTS

Dose effect curves were established for (188)Re and (99m)Tc for various extra- and intracellular distributions of the radioactivity. In the presence of perchlorate, no uptake of radionuclides was detected and (188)Re reduced cell survival more efficiently than (99m)Tc. A(37), the activity that is necessary to yield 37% cell survival was 14 MBq/ml for (188)Re and 480 MBq/ml for (99m)Tc. In the absence of perchlorate, both radionuclides showed similar uptakes; however, A(37) was reduced by 30% for the beta-emitter and by 95% for (99m)Tc. The dose D(37) that yields 37% cell survival was between 2.3 and 2.8 Gy for both radionuclides.

CONCLUSIONS

Uptake of (188)Re and (99m)Tc decreased cell survival. Intracellular (99m)Tc yielded a dose increase that was higher compared to (188)Re due to emitted Auger and internal conversion-electrons. Up to 5 Gy there was no difference in radiotoxicity of (188)Re and (99m)Tc. At doses higher than 5 Gy intracellular (99m)Tc became less radiotoxic than (188)Re, probably due to a non-uniform lognormal radionuclide uptake.

摘要

目的

细胞放射性核素摄取会增加生物结构吸收剂量的不均匀性。剂量的增加取决于放射性同位素的摄取率和发射特性。我们使用体外模型比较了细胞摄取（188）Re-高锝酸盐和（99m）Tc-高锝酸盐对细胞存活的影响。

材料和方法

在存在或不存在高氯酸盐的情况下，将培养的大鼠甲状腺 PC Cl3 细胞与（188）Re 或（99m）Tc 孵育 1 小时。通过集落形成测定克隆形成细胞存活。此外，还定量了细胞内放射性核素摄取。

结果

为放射性核素的各种细胞内外分布建立了（188）Re 和（99m）Tc 的剂量效应曲线。在存在高氯酸盐的情况下，未检测到放射性核素的摄取，（188）Re 比（99m）Tc 更有效地降低细胞存活率。A(37)，产生 37%细胞存活率所需的活性为 14 MBq/ml 用于（188）Re 和 480 MBq/ml 用于（99m）Tc。在不存在高氯酸盐的情况下，两种放射性核素的摄取相似；然而，β发射体的 A(37)减少了 30%，（99m）Tc 减少了 95%。产生 37%细胞存活率的剂量 D(37)对于两种放射性核素均在 2.3 至 2.8 Gy 之间。

结论

（188）Re 和（99m）Tc 的摄取降低了细胞存活率。与（188）Re 相比，细胞内（99m）Tc 产生的剂量增加更高，这是由于发射的俄歇和内转换电子。在高达 5 Gy 时，（188）Re 和（99m）Tc 的放射毒性没有差异。在高于 5 Gy 的剂量下，细胞内（99m）Tc 的放射毒性低于（188）Re，这可能是由于放射性核素摄取的不均匀对数正态分布所致。