摘要： 目的 探讨利用放射性核素153Sm体外标记胞嘧啶进行肿瘤代谢显像的可行性。方法 胞嘧啶与DTPA的偶联产物C-DTPA，经纯化后体外标记153Sm，并对得到的显像剂C-DTPA-153Sm的质量规格进行检测：①制剂要求：检菌，热原检测；②毒理学：急性毒理测定；③特殊参数：标记率，体外稳定性；④药动学：家兔血浆药物代谢动力学；⑤药效学：体外细胞显像，荷瘤小鼠显像。结果 体外实验、动物实验显示C-DTPA-153Sm为无菌、无热原、无毒性的安全制剂，并且可以在肿瘤部位浓集。结论 153Sm标记胞嘧啶代谢显像方法对多种肿瘤有诊断价值，可以无创性的体内评价肿瘤的增生状态，具有重要的临床应用价值。

Abstract: Objective To investigate the application of 153Sm labeled cytosine in tumor metabolic imaging. Methods The cytosine was labeled with 153Sm by DTPA coupled method, the final product was C-DTPA-153Sm. The labeled product was then purified. The determination of acute toxicity, in vitro stability, plasma pharmacokinetics in rabbits and imaging of cell and in tumor-bearing mice of radiolabeled cytosine were carried out. Results The results of examinations and animal experiments showed that the C-DTPA-153Sm was free of bacteria, pyrogen and toxic agents, and it could be concentrated at the tumor site in tumor-bearing mice. Conclusion C-DTPA-153Sm metabolic imaging might be used to evaluate the tumor growing status and may have important clinical value.