Advances In Plaque Brachytherapy For Choroidal Melanoma: Survival And Vision Outcomes : A Meta-Analysis Study

Abstract

Introduction: Choroidal melanoma is the most common primary intraocular malignancy in adults, associated with substantial risks of metastatic disease, visual morbidity, and mortality. Since the Collaborative Ocular Melanoma Study (COMS), plaque brachytherapy has become the standard eye-preserving treatment, with recent advances in isotope selection, plaque customization, imaging guidance, and adjunctive therapies. This meta-analysis aimed to evaluate survival and visual outcomes following plaque brachytherapy for choroidal melanoma, with a focus on the impact of these technical innovations.

Materials and Methods: A systematic search was conducted across PubMed, Scopus, Web of Science, and the Cochrane Library. Eligible studies included cohort and case-control studies reporting survival or visual outcomes in patients with choroidal melanoma treated with plaque brachytherapy. Data extraction was performed independently by two reviewers, and meta-analyses were conducted using STATA 14 and R (meta and metafor packages). Pooled hazard ratios (HRs), odds ratios (ORs), and weighted mean differences (WMDs) were calculated, with statistical significance set at P < 0.05. Subgroup analyses were performed based on isotope type (I-125, Ru-106, Pd-103), plaque design, and adjunctive therapies. Heterogeneity was assessed with the I² statistic, and publication bias was evaluated with funnel plots.

Results: A total of 12 studies comprising 4,386 patients met inclusion criteria. Pooled 5-year local tumor control was 95.1% (95% CI: 94.3–95.8), and 5-year metastasis-free survival was 90.4% (95% CI: 89.3–91.5). Visual acuity preservation was more variable, with 72.1% (95% CI: 70.4–73.8) of patients maintaining vision ≥20/200 at 5 years. Subgroup analyses indicated no significant survival differences between I-125 and Ru-106, while Pd-103 plaques demonstrated a trend toward reduced radiation-related toxicity, particularly retinopathy. Improved vision outcomes were observed with customized plaque designs and adjunctive anti-VEGF therapy.

Conclusion: Plaque brachytherapy provides durable local control and favorable survival outcomes for patients with choroidal melanoma, confirming its role as the standard eye-preserving treatment. Advances in isotope selection, plaque design, and adjunctive therapy have contributed to reduced toxicity and modest improvements in visual outcomes, although long-term vision preservation remains a challenge. These findings support continued refinement of brachytherapy techniques and highlight the need for further prospective research on adjunctive strategies.