Stereotactic radiosurgery of large uveal melanomas with the gamma-knife

Objective: To present our experience with the Gamma-knife in treating large uveal melanomas with stereotactic radiosurgery. Design: Prospective, noncomparative, interventional case series. Participants: Fifty-eight patients with unilateral uveal melanomas were tre ated from 1996 through 1999 with stereotactic radiosurgery using the Gamma- knife. From these we report the results of 35 patients who had a follow-up of more than 1 year after irradiation. Intervention: Stereotactic radiosurgery with the Gamma-knife. Main Outcome Measures: Tumor control, maximum apical tumor height, eye rete ntion rate, and visual acuity. Results: In 34 eyes (97%), local tumor control was achieved. The maximum ap ical tumor height decreased from a median of 9.1 mm (95% confidence interva l [CI], 3.2-13.9 mm) before treatment to 6.2 mm (95% CI, 2.1-11.9 mm) at 1 year after treatment (P < 0.001, paired t test). The tumor volume decreased from a median of 0.8 cm(3) before treatment to 0.5 cm(3) 1 year after trea tment (P < 0.001, paired t test). Two eyes required enucleation (one radiat ion failure, one secondary glaucoma). The median visual acuity decreased fr om 20/60 (95% CI, hand movement [HM] to 20/20) before treatment to 20/200 ( 95% CI, HM to 20/30) at 1 year after treatment (P = 0.001, paired t test). Conclusions: Stereotactic radiosurgery using the Gamma-knife is an alternat ive to enucleation in treating large uveal melanomas. The visual function m ay be preserved in selected cases. (C) 2000 by the American Academy of Opht halmology.