Iodine-125 episcleral plaque therapy in uveal melanoma

Purpose: To assess the efficacy of iodine-125 (I-125) episcleral plaque therapy in the management of uveal melanoma with regard to local control, survival, globe preservation and visual outcome. Methods: Between January 1985 and January 1997, 50 patients with the diagnosis of uveal melanoma were treated with I-125 episcleral plaques. The mean initial tumour height was 5.5 mm (range, 2.0-9.5 mm) and basal diameter 9.5 mm (range, 4.0-14.5 mm). I-125 seeds with a mean activity of 1259.1 MBq were used. The mean apical dose was 80.5 Gy (range, 68.0-95.0 Gy). Scleral dose ranged from 225.0 to 940.0 Gy. Pretreatment visual acuity was 6/60 or better in 43 patients. Results: One patient was lost to follow up and excluded from analysis. The remaining 49 patients had a mean follow up of 39.5 months. There were seven local failures, with a mean duration to tumour progression of 16.7 months. All seven patients were successfully managed with enucleation. Five other enucleations were performed for treatment- related complications. At the time of analysis, 10 patients have died, five of metastatic melanoma. Of the patients with preserved globes, corrected visual acuity was 6/60 or better in 31 patients. Conclusions: Good local tumour control and survival can be achieved with episcleral plaque therapy. Globe preservation with useful vision was possible in the majority of cases. Our findings are in keeping with other reported series.