~(99m)Tc标记抗卵巢癌单克隆抗体放射免疫导向手术的实验研究

目的：进行99mTc标记卵巢癌单抗放射免疫导向手术研究，为临床应用提供基础。方法：采用改进预锡法标记COC183B2-F(ab′)2和正常鼠IgG(NMIgG)，并分别向荷人卵巢癌裸鼠体内注入99mTc-COC183B２-F(ab′)2(单抗组)和99mTc-NMIgG(对照组)。首先在体外进行放射免疫显像(RII)初步决定探测时机，然后采用肿瘤探测仪(GDP)进行体内肿瘤及临近正常组织放射性测量，并计算肿瘤与非肿瘤放射性比值(T/NT)。结果：1改进预锡法单抗99mTc标记率达95%以上，标记后免疫组化染色显示标记物保留较好免疫活性；2GDP体内探测肿瘤最小为0.3cm×0.1cm，分辨瘤与正常组织间最小距离为0.2cm；T/NT(肝)为3.27±0.64、T/NT(脾)为2.23±0.47、T/NT(小肠)为3.33±0.84、T/NT(肌肉)为4.68±0.81，术中可以T/NT比值大于2为肿瘤阳性诊断标准；3RII和GDP体内探测显示，18h后可进行99mTc标记单抗片段放射免疫导向手术。结论：99mTc标记单抗进行卵巢癌放射免疫导向手术可行，有望用于临床。

Experimental study of radioimmunoguided surgery with99mTc labeling monoclonal antibody in ovarian carcinoma

Objective:To study radioimmunoguided surgery (RIGS) s ystem with99mTc labeling monoclonal antibody (McAb) for detection of o v arian carcinoma in nude mice bearing human ovarian carcinoma.Methods:McAb COC183 B2-F(ab′)2 and normal mice IgG labelled with99mT c were prepared according to improved pretining method and were injected respect ively into two groups of nude mic e bearing human ovarian carcinoma with ascites.Radioimmunoimaging(RII) were perf ormed before operations to determine the correct time of operation.The radioact ivity of tumor and their neighboring tissues were measured by GDP in vivo and co mpared with gamma well counts after dissection i n vitro.Results:COC183B2-F(ab′)2 labelled with99m Tc yielded a label ing rate of over 95% and a good immunoactivity.The detection of carcinoma tissue by GDP showed T/NT(liver) 3.27±0.64，T/NT(spleen) 2.23±0.47,T/NT(intestine)0. 33±0.84,T/NT(muscle)4.68±0.81 and T/NT ratio of 2:1 was diagnosed positive for cancer.The smallest carcinoma detected was 0.3cm×0.1cm and the ne arest distanc e between carcinoma and normal tissue was 0.2cm.The results by RII and GDP showe d that the operation should be performed in 18 hours after injecting99m Tc labelled COC183B２-F(ab′)２.Conclus ions:The above studies proved that RIGS with99mTc labelled COC18 3B2-F(ab′)2 is practical and hopefully be used clinically for ovarian carci noma.