Primary orbital melanoma treated with iodine-125 plaque radiotherapy.

PURPOSE: To report a case of primary orbital melanoma successfully managed by custom-designed iodine-125 plaque. DESIGN: Case report. METHODS: A 59-year-old man with no systemic or secondary melanocytic tumor was diagnosed with primary orbital melanoma after transconjunctival incisional biopsy. He was treated with unshielded iodine-125 plaque (90 Gy) that was sutured to the sclera. The radiation plan was calculated to safely target the initial tumor volume and any residual intrascleral or loose orbital melanoma cells that could have been disseminated to the surrounding orbital tissues during incisional biopsy. RESULTS: After 66 months' follow-up, the patient was still alive with partial remission of his liver metastases. Routine orbital magnetic resonance imaging studies confirmed the lack of orbital recurrence. CONCLUSIONS: Plaque radiotherapy appears to be a reasonable alternative to exenteration or external irradiation for orbital melanoma after biopsy confirmation.