Ultrasound Verification of Plaque Brachytherapy Placement in Patients Treated for Primary Uveal Melanoma: A Single-Center Experience.

Introduction: Proper plaque positioning is essential for effective episcleral plaque brachytherapy and can be verified using ultrasound. In this study, we show our center's protocol for intraoperative ultrasound verification of plaque placement and present our single-center local recurrence data in patients with primary UM involving the choroid and/or ciliary body. We also indicate our center's distance metastasis rate for patients presenting with primary UM.

Methods: All patients who presented to our institution with UM of the choroid and/or ciliary body between May 2017 and March 2022 and treated with plaque brachytherapy were enrolled. Endpoints include the 24-month local recurrence-free rate (primary) and 24-month metastasis rate (secondary), both estimated using the Kaplan-Meier method (KM).

Results: Local Recurrence: 176 patients met the study criteria with median follow-up of 23.2 months. The 24-month recurrence-free probability for this cohort was estimated at 99.1% (95% confidence interval: 0.974-1.00). Metastatic Recurrence: 136 of these patients underwent at least one follow-up surveillance scan. The 24-month metastasis-free survival probability in our cohort was estimated at 87% (95% confidence interval: 81-94%).

Conclusions: We show improved local control utilizing ultrasound verification compared to historical controls who received TTT and brachytherapy without intraoperative ultrasound confirmation.