Purpose: To report our experience in treating medium-size ocular melanomas with custom-made "Nag" eye plaques.
Methods: Seventy-eight patients with medium-size ocular melanomas were treated with plaques of 0.6-mm-thick, 18k gold with a radius of curvature of 12 mm to conform to the curvature of the eyeball. These plaques were custom-made in various sizes and shapes to encompass the base of the tumor and a 1-mm margin on all sides. Apertures in three wings of these plaques allowed sutures to be easily placed to hold the plaques onto the sclera. A dose of 100 Gy (before TG-43) or 85 Gy (after TG-43) was delivered with (125)I in 4 days. The dose was prescribed to the periphery of tumor at the level of tumor apex to ensure that the entire tumor volume received at least this dose.
Results: The median follow-up was 49 months (range 8-112 months). The progression-free survival (Kaplan-Meier method), overall survival, and disease-specific survival at 5 years were 93%, 86%, and 97%, respectively. Fifty of 78 (64%) patients retained useful visual acuity (20/200 or better). Thirty-one of 78 (40%) patients developed retinopathy or papillopathy. In the subgroup of 22 patients with tumor distance < or =2 mm from optic disc or macula, 12 patients (54%) developed retinopathy or papillopathy. Only 7 of these patients (32%) had useful vision (20/200 or better). Short distance to optic disc or macula was associated with significantly poor visual acuity and moderate to severe retinopathy or papillopathy (ANOVA, p = 0.004 and p = 0.002, respectively).
Conclusion: Our experience suggests that custom-made Nag plaque brachytherapy can control medium-size choroidal melanoma and that a 1-mm, rather than the standard 2-mm, minimum margin is sufficient when this plaque and prescription methods are used. Patients with tumors close (< or =2 mm) to optic disc or macula have a significantly poorer visual outcome.