^(99m)Tc-DTPA细胞水平分布的实验研究

An experimental study of microdistribution of ^(99m)Tc-DTPA at cellular level

目的核医学中传统的MIRD剂量估算方法是假设放射性药物在器官内均匀分布,用器官的平均剂量描述每个细胞及细胞核的剂量。基于核素的微观分布数据,建立微剂量的剂量估算模式,从而为核医学中诊疗计划的制定、放射药物效果和危害的预测及评价、分子核医学研究提供基础的微剂量估算及其分布研究的方法和基础数据。方法采用了放射自显影术和冰冻切片技术,建立自显影银颗粒密度与放射性药物强度的刻度曲线,确定放射性药物99mTcDTPA的微观分布。结果银颗粒密度与施入比活度的相关系数为0.9915,刻度系数为6.48×10-5Bq。细胞浆与细胞核的分布比为1.78。结论放射性药物在细胞水平的分布是不均匀的,因此在计算细胞水平的剂量时应考虑到其分布的不均匀性。

Objective Traditional MIRD method for dose assessment in nuclear medicine assumes that radionuclide is homogeneously distributed in organs, and the dose to cells and cell nucleus is presented by mean dose to the organ. This project will provide the basic method and data for planning diagnosis and treatment in nuclear medicine, for predicting and evaluating effect and risk of radio-pharmaceuticals, and for further research of microdosimetry at molecular level in nuclear medicine and biology. Method The article will describe the microdistribution of ^99m Tc-DTPA using microautoradiography and frozen sectioning technique. Results To describe the relationship between argent grain density and nuclide radioactivity a regression curve was depicted and the R value was calculated to be 0.9915. The grain density over cytoplasm was 1.78 times higher than that over nucleus in these cells. Conclusion The distribution of radiomedicament at cellular level is nonuniform.