摘要
目的 观察１３１Ｉ抗ＣＥＡ单抗（Ｃ５０） 在结肠癌生物体内的生物学分布，评估１３１ＩＣ５０ 在机体内的导向作用及其稳定性。方法 采用改良氯胺Ｔ 法以１３１ＩＣ５０ 进行荷人结肠癌裸鼠及结肠癌患者体内生物学分布及肿瘤放免显像研究。每鼠腹腔内注射１３１ＩＣ５０ １００ μＬ（３ ７００ ｋＢｑ）。１，２ ，３ ，４ 和６ 天后显像并测定各脏器的放射性分布；每例结肠癌患者静脉注射１３１ＩＣ５０ １ ｍｇ （１６０ ＭＢｑ） ，４８ ～７２ 小时后采用单光子发射型计算机辅助断层仪（ＳＰＥＣＴ） 进行扫描显像，２ ～３ 天后于术中采集肿瘤及正常组织并检测其放射性分布。结果 荷人结肠癌裸鼠注射标记抗体后４８ 小时肿瘤区即有放射性浓聚，随着时间的推延，影像渐趋清晰，本底逐渐下降。第６ 天结束时，瘤／肠和瘤／血放射性计数比值（Ｔ／ＮＴ） 分别为１０－４０ ±０－６９ 和０－７０ ±０－０８ ，均达最大值。１３１ＩＣ５０ 在结肠癌患者体内不同组织的生物学分布则显示：１３１ＩＣ５０ 在瘤区明显集聚，Ｔ／ＮＴ 多数达５ 以上。显像结果清晰，血本底很低。结论 １３１ＩＣ５０ 在生物体内能与肿瘤抗原发生特异性结合，具有很好的导向性，且在内环境下稳定性?
Objective To investigate the biodistribution of 131 I anti CEA monoclonal antibody (C50) in nude mice model and patients of colon cancer and evaluate the guiding value of the stability of 131 I C50in organism . Methods The anti CEAmonoclonalantibodylabeled with 131 I by modified chloramine Tmethod wasinjected intra abdominallyinto nude mice modeland injected intravenously into patients.Each mouse was admitted 131 I C50 100 μl(3 700 kBq) .1 ,2 ,3 ,4 and 6 day later, radioim munotomographing was performed and radioactivity of different tissues was counted. Each patient was admitted 131 I C50 1mg (160 MBq) . After 48 to 72 hours radioim munotomographing was made by SPECTand reconstructed by special procedures.In the operation various specimens were taken and their radioactivities were counted by well type scintillation counter. Results Satisfactoryimaging was obtained at 48th hourafterinjection and at the 6th day T/NT(tumor/colon) reached 10-40 + 0-69 and T/NT(tumor/blood) reached 0-70 + 0-08 .In colon cancer patients most ofthe ratios oftumorradioactivity over normaltissue (T/NT) were above 5 . 131 I C50 intensively concentrated at the periphery of tumors. The optimal images were obtained. Conclusion 131I 50 can combine with tumor antigenic determinant specifically in modeland patient ofcolon cancer.It has optimaltargeting effect and good stability .
