Fani Melpomeni, Xanthopoulos Stavros, Archimandritis Spyridon C, Stratis Nikolaos, Bouziotis Penelope, Loudos George, Varvarigou Alexandra D
Institute of Radioisotopes-Radiodiagnostic Products, National Center for Scientific Research Demokritos, 153 10, Athens, Greece.
Anticancer Res. 2003 May-Jun;23(3A):2195-9.
The anti-CEA monoclonal antibody, which selectively localizes in colon cancer, was labeled with Samarium-153 (153Sm). 153Sm is mainly a beta-emitter which can be used for therapeutic purposes, while its gamma-ray facilitates imaging studies. Labeling was achieved using the bicyclic anhydride of DTPA as chelator for Sm-153 tagging onto the antibody. [153Sm]anti-CEA was biologically evaluated in nude mice bearing tumors of different weight (0.5-2.5 g), at diverse time intervals (4-72 hours), by anatomic and imaging methods. Biodistribution studies showed slow blood clearance and high retention in the liver, kidneys and lungs. In nude mice bearing tumors of about the same weight, uptake increased with time, from 4 to 72 hours post injection (p.i.). Highest uptake was observed in 0.5-0.8 g tumors compared to those of 1.5-2.5 g. The results agreed with imaging studies performed on a gamma camera at 4 to 72 hours p.i. Tumor uptake depended on time and tumor weight. The tumor can be visualized 24 hours p.i. but, due to the high background, it can be clearly distinguished at 72 hours p.i.
能选择性定位于结肠癌的抗癌胚抗原单克隆抗体用钐 - 153（153Sm）进行标记。153Sm主要发射β射线，可用于治疗目的，而其γ射线有助于成像研究。标记是通过使用二乙三胺五乙酸的双环酸酐作为螯合剂，将Sm - 153标记到抗体上实现的。通过解剖学和成像方法，在不同体重（0.5 - 2.5 g）的荷瘤裸鼠中，于不同时间间隔（4 - 72小时）对[153Sm]抗癌胚抗原进行生物学评估。生物分布研究表明，血液清除缓慢，在肝脏、肾脏和肺中保留率高。在体重大致相同的荷瘤裸鼠中，从注射后（p.i.）4小时到72小时，摄取量随时间增加。与1.5 - 2.5 g的肿瘤相比，在0.5 - 0.8 g的肿瘤中观察到最高摄取量。结果与在注射后4至72小时用γ相机进行的成像研究一致。肿瘤摄取量取决于时间和肿瘤重量。注射后24小时可观察到肿瘤，但由于背景较高，在注射后72小时可清晰分辨。
