Radiation complications and tumor control after 125I plaque brachytherapy for ocular melanoma

Abstract

To determine the outcome of 125I plaque brachytherapy at our institution and identify the risk factors associated with the development of radiation complications, tumor recurrence, and metastasis. From 1986 to 2000, 156 patients underwent 125I episcleral plaque (COMS design) application for the treatment of ocular melanoma. Chart analysis of follow-up ophthalmologic appointments assessed the incidence of ocular side effects after therapy. Statistical analysis assessed outcomes and significant influencing factors. With a median follow-up of 6.2 years, the 5-year overall survival was 83%. The 5-year disease-specific survival was 91%. Initial local control at 5 years was 92%, with 100% ultimate local control after secondary therapy that included 9 enucleations. The risk of metastasis was 10% at 5 years and 27% at 10 years. Vision stayed the same or improved in 25% of patients, and 44% of patients maintained visual acuity better than 20/200. Thirteen percent of patients experienced chronic pain or discomfort in the treated eye. Dose rates to the tumor apex greater than 90 to 100 cGy/h were associated with increased systemic control but worse radiation toxicity. Patients in our series experienced excellent local tumor control. Higher dose rates to the tumor apex were associated with reduced rates of distant metastases but worse ocular function.