Radioimmunoscintigraphy Using Monoclonal Antibodies to CEA, CA 19-9 and CA 125

Abstract

131I labelled F (ab’)2 fragments of monoclonal antibodies against CA 19-9 and CEA (“radioimmunococktail” IMACIS 1) were used in a prospective study (n = 60 patients) and in a retrospective study (n = 32 patients) for the detection of colorectal carcinomas (n = 67) and other gastrointestinal CEA/CA 19-9-producing tumors (n = 32). Sensitivity was 82% and specificity 90%. Immunoscintigraphy proved useful and complementary to CT scan and sonography, especially in the diagnosis of pelvic recurrences and intra-abdominal metastases. In addition, monoclonal antibody OC 125 (IMACIS 2) was used for the detection of ovarian carcinomas (n = 10) and other CA 125 producing tumors. Immunoscintigraphy was positive in all patients (n = 18) suggesting that this radioimmunological approach could be of use in the staging, therapeutic control and earlier diagnosis of recurrent epithelial ovarian carcinoma.