Clinical outcome of eye-preserving treatment with ruthenium-106 brachytherapy for choroidal melanoma

Abstract

Purpose: In our institution, patients with choroidal melanoma have been treated with ruthenium-106 (Ru-106) brachytherapy with or without additional local therapy since 2006. The aim of this study is to report early clinical outcomes of eye-preserving treatment strategy for choroidal melanoma of variable size

Patients and methods: Ninety-three consecutive patients diagnosed of uveal malignant melanoma were treated with Ru-106 brachytherapy between October, 2006 and December, 2012. Patients with iris and ciliary body tumor were excluded (n = 5), leaving 88 patients for analysis. In our institution, malignant melanomas of variable size were treated with Ru-106 brachytherapy and most of the medium to large sized tumor (height ≥6 mm) received combined therapy adding local excision and/or transpupillary thermotherapy (TTT). In general, 85-95 Gy was prescribed to the apex of the tumor for patients without local excision, and 100 Gy to the 2-mm point from the outer surface of the sclera for patients undergoing tumor excision.

Results: Median follow-up was 30 months. The median age of all cohort was 50 years (range 19-82 years). Median basal diameter was 11.4 mm (range 2.96-17.28 mm) and tumor height was 6.79 mm (range 1.73-13.66 mm). The actuarial 3-year local control rate was 80%. Distant metastases were diagnosed in 12 patients and a total of 11 patients died. Actuarial metastases-free survival rate was 84% and overall survival rate was 90.3% at 3 years. Among the 88 patients, 13 patients eventually underwent enucleation, resulting in a 3-year eye-preservation rate of 80%: 12 patients underwent enucleation for local recurrence and 1 for complication. Significant prognostic factor for eye-preservation rate was tumor height (p = 0.042). The number of patients with tumor height ≥6 mm was 50 (57%) and additional local therapy was used in the treatment of 94% (n=47) of these patients. Three-year eye-preservation rate was 94% for tumor height <6 mm, and 70% for tumor height ≥6 mm (p = 0.047). Only 1 patients with tumor size <6 mm (n = 38) experienced distant metastasis and eventually died of disease.

Conclusion: Ru-106 brachytherapy for choroidal melanoma of variable size showed favorable outcome. Additional local treatment may improve eye preservation rate in medium to large size tumor.