Immunoscintigraphy with 99mTc labelled F(ab')2 fragments of an anti melanoma monoclonal antibody (225.28S) in patients with metastatic malignant melanoma.

Immunoscintigraphy was performed in 25 patients with malignant melanoma using a 99mTc labelled monoclonal antibody (225.28S). In four cases, imaging was repeated following treatment with recombinant gamma interferon. In 11 cases, tissue samples of metastatic lesions were investigated for the expression of melanoma associated antigens by immunohistochemical techniques. Overall, 59% of known lesions were detected by imaging. The highest rates of detection were in bone, liver and lymph nodes and the lowest in lung, stomach and bowel. Six lesions were detected which had not shown up on routine clinical and radiological examination. There was no evidence of enhanced or induced HMW-MAA expression following interferon treatment. This technique has been found to be useful in staging patients and has been free from side effects.