Comparison of episcleral plaque and proton beam radiation therapy for the treatment of choroidal melanoma

Purpose: To compare the efficacy of iodine-125 (I-125) and ruthenium-106 (R u-106) episcleral plaque radiation therapy and proton beam radiation therap y (PBRT) in the treatment of choroidal melanoma. Design: A retrospective, nonrandomized comparative study. Methods: Charts of patients treated with I-125, Ru-106, and PERT for choroi dal melanoma between January 1988 and June 1996 at St. Bartholomew's Hospit al and Moorfields Eye Hospitals were reviewed. Main Outcome Measure: Local control of choroidal melanomas after I-125,Ru-1 06, Or PERT. Results: A total of 597 patients were identified (I-125 = 190, Ru-106 = 140 , PERT = 267). Patients treated with Ru-106 had a significantly greater ris k of local tumor recurrence than did patients treated with either I-125 (P = 0.0133; confidence interval [CI], 1.26-7.02; risk ratio, 2.97) or PERT (P = 0.0097; CI, 1.30-6.66; risk ratio, 2.94). A stepwise Cox proportional ha zard model found maximal basal diameter to be a significant covariate (P = 0.0033). Conclusion: Patients treated with Ru-106 had a significantly greater risk o f local tumor recurrence than did those patients treated with either I-125 or PBRT.