Iodine-125 Episcleral Plaque Brachytherapy for AJCC T4 Posterior Uveal Melanoma: Clinical Outcomes in 158 Patients

Background/Aims: The aim of this study is to report the burden of ocular morbidity following iodine-125 episcleral plaque brachytherapy (EPBT) in the treatment of American Joint Committee on Cancer (AJCC) T4-staged posterior uveal melanoma (PUM). Methods: Clinical records of patients with T4-staged PUM treated with 125I EPBT were analyzed for incidence of treatment failure and radiation-induced complications. Results: Cumulative incidence of local treatment failure was 9% (95% CI 5-15%) at 5 years and was associated with decreased tumor height (HR = 0.78; p = 0.01). Cumulative incidence of enucleation at 5 years was 21% and was correlated with worsening baseline visual acuity (HR = 1.42; p = 0.05). Increasing patient age was associated with higher rates of vitreous hemorrhage (HR = 1.03; p = 0.02) and cataract surgery (HR = 1.05; p < 0.001). Increased tumor height was associated with higher rates of neovascular glaucoma (HR = 1.16; p = 0.03) and vitreous hemorrhage (HR = 1.23; p < 0.001). Conclusion: 125I EPBT is an effective treatment for T4-staged PUM and achieves high rates of local control. Treatment failure appears to be more common among minimally elevated tumors. Other causes of ocular morbidity were associated with increasing tumor height, patient age, and baseline visual acuity.