Radioimmunodetection of human melanoma with indium-111-labeled monoclonal antibodies

Our purpose in conducting this study was to evaluate the efficacy of an 111In-labeled murine monoclonal antibody directed against a high-molecular-weight glycoprotein in localizing metastatic melanoma in 15 patients with previously documented disease and to determine the effect of antibody mass (2.5, 5.0, and 10.0 mg) on blood clearance, biodistribution, and lesion detection. Five mCi of 111In-antibody were infused over 1 hour, and patients were scanned at 24 and 72 hours after injection without computer enhancement or background subtraction techniques. No significant differences in the organ distribution, urine excretion, or plasma disappearance curves were noted at the three antibody dose levels. There were no acute reactions. The scan detected tumor in 9 of 12 (75%) patients with active disease, and 26 of 33 (79%) lesions greater than 1 cm. Patient management in 3 of 15 (20%) of patients studied was changed as a result