Subfoveal choroidal melanoma: pretreatment characteristics and response to plaque radiation therapy.

Objective: To evaluate the clinical presentation, tumor characteristics, and response to palladium 103 plaque radiation therapy for subfoveal choroidal melanomas.

Methods: Retrospective case series of 50 patients diagnosed as having subfoveal melanoma and treated with plaque brachytherapy. Patients underwent evaluation for tumor characteristics, visual acuity, radiation damage, local tumor control, and metastatic disease.

Results: Patients were followed up for a median of 54 (SD, 49.3) months. Forty-nine tumors (98%) were dome shaped. Subretinal fluid (overlying or a dependent exudative retinal detachment) was evident in 34 of 45 patients (76%). Treatment involved an apical radiation dose of 82.8 Gy (delivered across 5-7 days), resulting in a mean dose of 157.7 Gy to the fovea. Pretreatment median visual acuity was 20/50, which declined to 20/180 at last follow-up. Visual acuity was better than 20/200 in 33 patients (66%) at baseline and 25 (50%) at last follow-up; 13 patients (26%) lost 6 or more lines of vision. Twenty-eight patients (56%) developed radiation retinopathy; 16 (32%) required secondary intervention for radiation retinopathy, including intravitreal antivascular endothelial growth factor therapy, laser treatment, cryotherapy, or pars plana vitrectomy. The local tumor control rate of subfoveal tumors was 92%. Four patients (8%) required secondary enucleation. Metastasis developed in 2 patients (4%).

Conclusions: Subfoveal choroidal melanomas in this series are almost exclusively dome shaped and likely to have an associated exudative retinal detachment. They are amenable to plaque radiation therapy. However, this tumor location is associated with a high incidence of radiation maculopathy and a low incidence of radiation cataract.