sodium-pertechnetate-tc-99m and Uveal-Neoplasms

The possibility of using radiolabelled monoclonal antibody fragments to image uveal melanomas has been assessed in a pilot study. 99mTc labelled F(ab')2 fragments of MoAb 225.28S raised against cutaneous melanomas were used. Initially 10 patients were imaged. In five patients the clinical findings were typical of uveal melanoma. Immunoscintigraphy was positive in all five cases. In a further five patients there was doubt about the diagnosis. One was though to have a choroidal haemangioma but failed to respond to treatment and immunoscintigraphy was positive, suggesting a diagnosis of melanoma. Two patients were assigned a diagnosis of choroidal haemangioma, one of melanocytoma or possible retinal pigment epithelium carcinoma, and one of metastasis. Immunoscintigraphy was negative in all these four cases. In combination with established diagnostic tests immunoscintigraphy may have a part to play in differentiating uveal melanoma from other similar tumours.

Topics: Adult; Aged; Antibodies, Monoclonal; Choroid Neoplasms; Diagnosis, Differential; Female; Hemangioma; Humans; Immunoglobulin Fab Fragments; Male; Melanoma; Middle Aged; Radionuclide Imaging; Skin Neoplasms; Sodium Pertechnetate Tc 99m; Uveal Neoplasms

A non-invasive method of detecting intraocular mass lesions is described which uses 67gallium citrate and 99m-technetium pertechnetate. It was used in 33 cases. In 73.7% of the patients with malignant melanoma of the eye there was a significant increase in the storage of the tracer. There was no difference in the results obtained with 67gallium citrate and 99m-technetium pertechnetate. Small, flat and peripheral tumors may not be detected. In some cases old intraocular hemorrhages may also lead to false-positive results. In contrast to the 32P-test the method described can be used in cases with opaque media. The radiation dose is about one-tenth of that given with the 32P-test.

Topics: Adolescent; Adult; Aged; Choroid Neoplasms; Diagnosis, Differential; Eye Neoplasms; Female; Gallium Radioisotopes; Humans; Iris Diseases; Male; Melanoma; Middle Aged; Nevus; Radionuclide Imaging; Sarcoma; Sodium Pertechnetate Tc 99m; Technetium; Uveal Neoplasms