Use of Ruthenium-106 Brachytherapy for Iris Melanoma: The Scottish Experience

Abstract

PurposeTo analyse long-term outcomes of ruthenium-106 (106Ru) plaque brachytherapy for the treatment of iris melanoma.MethodsWe retrospectively reviewed medical records of 19 consecutive patients with pure iris melanoma treated with 106Ru plaque brachytherapy between 1998 and 2016 at the Scottish Ophthalmic Oncology Service, Glasgow. The iris melanoma was treated with a ruthenium plaque placed on the corneal surface to deliver a surface dose of 555 Gy. We analysed vision preservation, local tumour control, radiation-related complications, eye retention rates, symptomatic metastasis and melanoma-related mortality.ResultsThe mean largest basal diameter of the lesions was 3.50±1.42 mm (range 1.6–6.5 mm), and the mean maximum height was 1.47±0.65 mm (range 0.7–2.8 mm). The tumour control and eye retention were 100% at a mean follow-up of 62 months (range 6–195 months). A 62% reduction in tumour height was observed on ultrasonography. Complications included cataract (68%), dry eye (47%), uveitis (37%) and scleral thinning (5%). At the final follow-up visit, the mean loss of Snellen visual acuity was 1.11±2.90 lines and vision of 6/9 or better was maintained in 53% of patients. None of the patients had evidence of symptomatic metastasis (non-imaged) or melanoma-related mortality.Conclusions106Ru plaque treatment for iris melanoma was highly effective a high tumour control, no tumour recurrences and a relatively a low complication rate.