Favorable Outcomes of Patients With High-Risk Uveal Melanoma Treated With a Novel Linear Accelerator-Based Frameless Fractionated Stereotactic Radiosurgery.

Purpose: Uveal melanoma (UM) represents the most prevalent and aggressive intraocular malignancy in adults. This study examined the outcomes of patients diagnosed with high-risk UM who underwent fractionated stereotactic radiosurgery (fSRS) treatment utilizing a novel Linear Accelerator (LINAC)-based frameless technique.

Design: Retrospective, interventional case series.

Methods: All patients received fSRS, 50 Gy in 10 Gy/fraction, every other day on a stereotactic LINAC with a novel in-house eye localization and monitoring system. Tumor control, vision outcome, as well as acute and late toxicities were evaluated.

Results: This study included 23 patients with high-risk UM. Median age was 64.8 years old (range 37.9-85.1 years). The Median Karnofsky Performance Score was 90 (range 70-100). The median tumor diameter was 13.5 mm (range 3.0-24.0 mm), and median tumor thickness was 5.05 mm (range 1.2-15.1 mm). There were 11 patients (47.8%) who received prior episcleral plaque. The other 12 patients received stereotactic radiotherapy for initial treatment. With a median follow-up of 38 months, the local control rate was 95.6% at 1 year, 90.1% at 2 years, and 85.6% at 3 years. There was no significant difference between treatment-naïve patients and those who had previously received plaque treatment. Eye preservation rate was 91.3%, with 2 patients required enucleation for tumor progression and/or toxicity. High-grade acute adverse events included 1 patient with grade 3 eye pain. The median best-corrected visual acuity by LogMAR was 0.5 pretreatment (Snellen conversion 20/63) and 1.0 (Snellen 20/200) post-treatment.

Conclusions: Our institution's novel LINAC-based frameless fSRS demonstrated favorable local control and toxicity profile for high-risk UM (tumors deemed unsuitable for episcleral plaque brachytherapy). Patients maintained a high rate of eye preservation. This approach provides an eye preservation option for patients unable to have plaque radiotherapy.