A technetium-labeled monoclonal antibody for imaging metastatic melanoma

Twenty patients with histologically proven metastatic melanoma were scanned with a 99mtechnetium (99mTc)-labeled melanoma antibody to determine the detection rate of known malignant lesions and to evaluate the antibody's ability to discover occult metastases. Isotope localization in different organs was as follows: liver 100%, bone 100%, subcutaneous lesions 80%, lymph nodes 54%, and lung 33%. Four unsuspected bone lesions and 16 occult subcutaneous lesions were found. False positive lesions were noted in two instances--one benign thyroid adenoma, and one arthritic bone lesion. One patient developed an atypical serum sickness reaction with a rash and arthralgias that responded rapidly to treatment. The 99mTc antimelanoma antibody is a safe and effective method to detect metastatic melanoma. It has potential use for screening newly diagnosed melanomas that carry an increased risk of recurrence.