title: Evaluation of immunolocalization in gastrointestinal cancer.
abstract: Tumor localization by a 131I-labeled monoclonal antibody to CEA has been evaluated in a series of 50 patients with clinically suspected primary or recurrent gastrointestinal cancer. Eighty-five percent of the primary tumors were correctly detected, as were 43% of associated nodal metastases. Localization was compared with computerized tomography in the detection of recurrent disease. Each technique correctly identified 61% of the sites but missed 39%. In addition, labeled antibody localization produced a significant number of false-positive images. Radioactivity accumulated by tumors, both primary and secondary, was significantly higher than that in surrounding normal tissue (P less than .01). However, less than 0.8% of the injected radioactivity and 0.01% of the injected antibody were detectable in the tumors. Radiolabeled antibody was rapidly cleared from the circulation, and this may reflect a recipient reaction to the foreign protein.
mesh_terms: D000911:Antibodies, Monoclonal / Q000097:blood; D002272:Carcinoembryonic Antigen / Q000276:immunology*; D005069:Evaluation Studies as Topic; D006801:Humans; D007414:Intestinal Neoplasms / Q000000981:diagnostic imaging* / Q000276:immunology; D007457:Iodine Radioisotopes; D008207:Lymphatic Metastasis; D009364:Neoplasm Recurrence, Local / Q000175:diagnosis; D011877:Radionuclide Imaging / Q000379:methods; D013274:Stomach Neoplasms / Q000000981:diagnostic imaging* / Q000276:immunology; D014056:Tomography, X-Ray
chemical_list: D000911:Antibodies, Monoclonal; D002272:Carcinoembryonic Antigen; D007457:Iodine Radioisotopes