Radioimmunodetection of cancer with radioactive antibodies to carcinoembryonic antigen

摘要: Abstract Our recent clinical experience in the radioimmunodetection of cancer 142 patients with a proven history is summarized. 131 I-labeled affinity-purified goat immunoglobulin G having 70% immunoreactivity carcinoembryonic antigen (CEA), representing radiation dose ranging from 0.7 to 2.1 mCi/70 kg patient (2 3 µg/kg protein), was administered i.v. Anterior, posterior, and lateral radioscans chest abdomen were made routinely at 24 48 hr γ-scintillation camera. Computer-assisted processing images order subtract 99m Tc background radioactivity used enhance tumor-related activity, this method resulting an average 2.5-fold enhancement tumor images. A very high percentage detection achieved most epithelial cancers studied. The overall sensitivity (true-positive rate) four major types studied as follows: colorectal cancer, 85%; ovarian 88%; cervical 90%; lung 71%. specificity (true-negative likewise high, 83 100%. In some cases, positive when other methods failed. smallest tumors detectable by appeared be about 2 cm. Metastatic could localized number normal plasma CEA titers, although colorectal, cervical, there correlation between elevation. general, however, more reliable detecting among population than assay results. High amounts circulating did not appear prevent successful radioimmunodetection. No untoward or hypersensitivity reactions found studied, even repeated. Evaluation findings revealed 116 nonneoplastic benign disease conditions, which only showed evidence radioantibody localization (less 2%). Administration radiolabeled 22 patients, whom already shown for radioactive antibody, resulted 4 32 sites transient radiolocalization; these massive lesions least 10 cm diameter.