~(131)I-抗CEA单克隆抗体免疫显像诊断结、直肠癌的研究

用~(131)I标记抗CEA单克隆抗体对23例结、直肠癌患者和2例良性多发性结肠息肉患者进行了免疫闪烁显像研究,真阳性率91%,肝脏、卵巢及其他肠段的转移灶均获阳性显像,探测肝内最小转移灶为1cm,2例息肉患者均阴性。本文表明肿瘤/非肿瘤放射性比值须在2.0以上才能获阳性显像,坏死的肿瘤阳性率可明显下降。本法诊断的准确性达91%,高于B超、钡灌肠及其他核医学检查方法。

RADIOIMMUNIOSCINTIGRAPHY WITH I-131-LABELED ANTI-CEA MONOCLONAL ANTIBODY IN COLORECTAL CANCER PATIENTS

Twenty three colorectal carcinoma and two benign polyposispatients with operatively and histologically proven were studied by radioimmunioscintigraphy,using anti-CEA monoclonal antibodies(C14-17and C50)radiolabeled with I-131.Computer assisted processing for thesubtraction of Tc-99m background radioactivity was used to enhance thedetection and localization of tumor which is visualized by immune scinti-graphy.The size of tumor and the ratios of tumor to nontumor(T/NT)arevery important two factors for the external immunioscintigraphy.Theantibody uptake and retention in tumor are likely to depend on the degreeof vascularity and diffusion into the viable tumor mass.Based upon ourresults,the sensitivity of the method(true-positive)was 91%,its specificity(true-negative)was 100%.This study thus indicates that radioimmunioscin-tigraphy of cancer with radioactive anti-CEA monoclonal antibody is veryuseful in the diagnosis of patients with CEA-containing neoplasms.