I-123-IDAB: a new tracer for scintigraphic visualisation of malignant melanoma.

I-123-N-(2-Diethylaminoethyl) 4-lodobenzamide (I-123IDAB) has recently been introduced as a radiopharmaceutical agent in the management of patients with malignant melanoma. We tested the diagnostic potential of this substance in 5 patients suspected of having an ocular malignant melanoma. I-123-IDAB scintigraphy identified 4 patients with high tracer uptake in the pathologic eye. Three cases were confirmed histologic as a malignant melanoma, the fourth patient was submitted to radiotherapy. The amelanotic (histologically confirmed) irismelanoma of the fifth patient could not be detected. From these preliminary results we conclude that I-123-IDAB scintigraphy may be a valuable tool for establishing the diagnosis of malignant melanotic melanoma.