Staged I-125 Eye Plaque Brachytherapy for the Treatment of Large Uveal Melanoma: A Single Institution Experience.

Purpose: Eye plaque brachytherapy (EPBT) is not routinely performed on large uveal melanomas (UM) as commercially available plaques often cannot ensure adequate coverage of the tumor with high doses of 85 Gy. The purpose of this study is to report our institution's experience with a clinically novel approach of staged EPBT in treating large UM in 2 treatments, 45 Gy in each treatment.

Methods and materials: Patients were included if they underwent staged EPBT at our institution between 2020 and 2023.

Results: A total of 13 patients with a median age of 65 were included in this study. All patients were treated with Iodine-125 with a first-stage prescription dose of 45 Gy and with a second-stage treatment occurring at median 13 weeks after with prescription dose of 45 Gy. Median follow-up was 42 months, and local control was 100% with no patients requiring an enucleation for a local recurrence or other radiation-related toxicities. At last follow-up, all tumors were decreased in size. Visual acuity worsened in 11 patients, and other radiation-related toxicities included cataract, cystoid macular edema, radiation retinopathy, and neovascular glaucoma. Three patients developed metastases, one of whom died shortly after, while all other patients were alive at last follow-up.

Conclusions: Staged EPBT for large UM is a novel and feasible globe-preserving treatment with a high rate of local control. Ocular toxicities are expected but do not require enucleation. Further prospective randomized trials should be performed to validate this treatment approach.