Purpose: To evaluate the safety and efficacy of iodine 125 plaque brachytherapy (IBT) for large uveal melanomas.
Design: Retrospective, nonrandomized comparative trial (historical control).
Participants: One hundred twenty-one consecutive patients with a large uveal melanoma according to the Collaborative Ocular Melanoma Study (COMS) criteria who attended a national ocular oncology service.
Methods: Ninety-seven patients (80%) underwent primary IBT (mean dose to tumor apex, 87 Gy) with noncollimated 20- to 25-mm plaques. Assessment of metastatic disease at death and visual outcome followed COMS guidelines. Time to low vision (20/70 or worse) and blindness (loss of 20/400 vision) in the study eye were modeled by Cox proportional hazards regression, based on both single- and repeated-failure data sets. Person-years of retained vision were calculated.
Main outcome measures: All-cause and melanoma-specific survival, local and distant recurrence, and preservation of vision and cosmesis.
Results: Median tumor height was 10.7 mm (range, 4.5-16.8 mm), and largest basal tumor diameter was 16.1 mm (range, 7.3-25.0 mm). The Kaplan-Meier estimate for all-cause and melanoma-specific survival was 62% (95% confidence interval [CI], 49%-72%) and 65% (95% CI, 52%-75%) at 5 years. The corresponding estimate for local tumor recurrence was 6% (95% CI, 2%-14%) and for major cosmetic abnormality was 38% (95% CI, 26%-52%). The median visual acuity in the study eye was 20/100 at baseline and 20/1600 at 2 years after treatment. The Kaplan-Meier estimate for avoiding low vision and blindness was 11% (95% CI, 4%-24%) and 26% (95% CI, 16%-37%) at 2 years, respectively. Tumor height and location entirely posterior to the ora serrata were the most robust predictors of visual loss. In this series, 49 person-years without low vision (median, 0.6 years; range, 0.04-8.2 years) and 111 person-years without blindness (median, 1.0 years; range, 0.03-8.6 years) in the treated eye were conserved.
Conclusions: Iodine 125 plaque brachytherapy seems to be a safe and effective alternative to enucleation with regard to survival and local tumor control. It provides a fair chance of preserving the eye with acceptable cosmesis and a reasonable chance of conserving useful vision for 1 to 2 years.