ANTIMELANOMA MONOCLONAL-ANTIBODY 225.28S IMMUNOSCINTIGRAPHY IN METASTATIC MELANOMA

Background: Accurate staging and early detection of metastases are crucial to melanoma management. It would thus be of great value to have a widely available, cost-effective method that allows to examine the whole body and is more specific than current imaging modalities. Objective: The purpose of the study was to assess the value of immunoscintigraphy with Tc-99m-radiolabeled F(ab')2 fragments of the 225.28S monoclonal antibody in the staging of melanoma. Methods: 29 patients with known or suspected metastases were enrolled in the study and examined by monoclonal antibody fragment scintigraphy. The results were compared to physical examination, other imaging modalities and, where available, histology. Results: Antibody scintigraphy detected 9/34 metastases. There were 2 false-positive lesions. Diagnostic accuracy was 41%, sensitivity 26% and specificity 83%. Conclusion: Tc-99m-radiolabeled F(ab')2 monoclonal antibody-fragment scintigraphy cannot be recommended for staging of melanoma patients. The search for more sensitive radiopharmaceuticals for scintigraphy should thus be encouraged.