Diagnostic value of ocular melanoma immunoscintigraphy

To estimate the diagnostic value of ocular immunoscintigraphy (ISG) in the differentiation of melanoma from other ocular tumors or lesions.

ISG was performed in 27 patients. Twenty-four patients were suspected of having ocular melanoma and 3 patients had previous eye enucleation for melanoma and were without recurrent disease. Monoclonal antibody (MoAb) 225.28S was administered intravenously and the patient's head was imaged with gamma camera after 5 minutes and after 5 hours collecting 500.00 counts per image.

The diagnosis of malignant melanoma was established by clinical examination in 12 patients (10 of them were subjected to enucleation and histopathological confirmation). ISG was positive in 10 out of 12 patients (sensitivity 83%). Two patients with operated melanoma had negative scintigraphic result. Fifteen patients with non melanoma lesions had negative findings except one patient with haemangioma who had positive ISG. The specificity of ISG was 93%.

ISG is a sensitive and specific diagnostic method for ocular melanoma. The reliability of the results depends on proper acquisition of data and interpretation of images, including comparison of both eyes and early and late images with contrast enhancement.