Management of iris melanomas with 125Iodine plaque radiotherapy

To report the experience of the Princess Margaret Hospital/University Health Network with the treatment of iris melanoma (IM) with (125)Iodine plaque brachytherapy.

Retrospective noncomparative case series.

All cases of IM submitted to (125)Iodine plaque radiotherapy were included. Patients' demographic, clinical, management, and follow-up data were reviewed. Outcome measures included rates of tumor control, eye preservation, systemic metastases, and brachytherapy-related complications.

Fourteen IMs were included in the study. All patients had blue/green irises. Mean largest basal dimension and thickness were 7.1 +/- 2.1 mm (range, 4.0 to 11.5 mm) and 2.2 +/- 0.8 mm (range, 1.0 to 3.5 mm), respectively. Ten patients (71%) had seeding and 2 (14%) had glaucoma at presentation. Median follow-up was 26.6 +/- 19.5 months (range, 6 to 72 months). Tumor control was achieved in 100% of the cases and no eye was enucleated because of radiation-induced complications. At last visit, all patients were alive and free of metastasis. Final visual acuity was the same as or better than before treatment in 9 patients (75%). Cataract was the most common complication (8; 75%), followed by persistent glaucoma (2; 17%) and anterior uveitis (1; 8%). No other significant complication was seen during the follow-up period.

Plaque radiotherapy is a safe and effective conservative treatment option for IM, although cataract is a common, yet treatable, complication. This treatment scheme circumvents an intraocular procedure and may avoid the dissemination of malignant cells, and provides a margin of safety in the treatment of clinically undetectable disease.