放射自显影术用于细胞水平微吸收剂量分布研究

目的：研究放射性药物在小鼠肝脏细胞的微吸收剂量分布，试图建立估算的数学模式。方法：采用冰冻切片光阄放射自显影技术，研究99Tc^m－甲氧基异丁基异腈（MIBI）在小鼠肝脏细胞内细胞水平的分布。结果：99Tc^m－MIBI在肝脏细胞水平的分布是不均匀的，肝细胞核微吸收剂量数值与利用医学内照射剂量（MIBI）模式估算的结果差异较大。结论：该方法不仅可弥补MIRD模式的不足，而且可评估临床放射性药物治疗效果及剂量数据。

A study on microdosimetry of radiopharmaceuticals at cellular level by autoradiography

Objective In most situations, the spatial locations of radiopharmaceuticals are not uniform, so that in order to estimate the dose to cells and cell nuclei especially at the cellular or sub cellular level is necessary. Methods Autoradio graphy(ARG) is a method to obtain the precise spatial information of the radiolabels relative to the tissue histology. In the study, the microscopic locations of the radioactive substance in the liver of mice were investigated through microscopic frozen section ARG, and a mathematical model was developed, which can be conveniently used to microdosimetry, such as estimations of the doses received by the cell nuclei in rat liver after injection of 99 Tc m-MIBI via tail veins in this test. Results A comparison of the radiation dose rate estimates was conducted between the cellular dosimetry model and MIRD and significant differences were revealed. Conclusion ARG was proved to be a useful approach to provide detailed spatial and dosimetric information on radiopharmaceuticals within organs so that we can evaluate precisely the effectiveness of radiotherapy and radiotoxicity and microscopic radiation-effect in nuclear medicine.