Radioimmunodetection and Radioimmunotherapy of Malignant Melanoma: A Review

Radioimmunodetection utilizing monoclonal antibodies to various melanoma-associated surface antigens has been studied by several investigators during the past ten years. In the early trials, antibodies were labeled with ¹³¹I or ¹¹¹In, but now ^99mTc is almost exclusively used because of its more favorable energy for gamma camera imaging. Excellent specificity has been achieved in most studies, whereas sensitivity has been less good. In a recent European multicenter study on 493 patients sensitivity was 79% and specificity 96%. In this largest study on melanoma so far performed many previously unknown metastatic deposits were identified indicating that radioimmunodetection has a role in the management of metastatic disease. The clinical utility of immunoscintigraphy in localization of regional lymph node metastases has been documented in several investigations in recent years, indicating that this method can be used in the preoperative evaluation of patients. Radioimmunodetection has also been successfully used in the differential diagnosis of ocular lesions. However, conclusive evidence of improved patient outcome resulting from the earlier detection of melanoma lesions by immunoscintigraphy is still lacking. Anti-melanoma antibodies labeled with alpha- and beta-emitting isotopes are potential therapeutic agents, but so far there is little clinical experience with radio-immunotherapy of metastatic melanoma.