Supplementary Material for: Predictors of Local Recurrence and Progression-Free Survival in Iodine-125 brachytherapy-treated Uveal Melanomas: A modern institutional study

Introduction: Iodine-125 brachytherapy is an effective eye-sparing treatment for uveal melanoma. Previous work has shown that uveal melanomas cluster into distinct molecular classes based on gene expression profiles—discriminating low-grade from high-grade tumors. Our objective was to identify clinical and molecular predictors of local recurrence (LR) and progression-free survival (PFS). Methods: We constructed a retrospective database of uveal melanoma patients from the University of Miami’s electronic medical records that were treated between 8/1/2012-5/1/2019, with either COMS-style or Eye Physics plaque. Data on tumor characteristics, pre-treatment retinal complications, post-plaque treatments, LR and PFS were collected. Univariate and multivariate Cox models for cumulative incidence of LR and PFS were conducted using SAS version 9.4. Results: We identified 262 patients, with a median follow-up time of 33.5 months. 19 patients (7.3%) had local recurrence and 56 patients (21.4%) were classified as PFS. We found that ocular melanocytosis (HR = 5.55, p < 0.001) had the greatest impact on PFS. Genetic expression profile did not predict local recurrence outcomes (HR = 0.51, p = 0.297). Conclusion: These findings help physicians identify predictors for short-term brachytherapy outcomes allowing better shared decision making with patients pre-operatively when deciding between brachytherapy vs. enucleation. Patients stratified to higher risk groups based on pre-operative characteristics such as ocular melanocytosis should be monitored more closely. Future studies must validate these findings using a prospective cohort study.