Stereotactic radiosurgery of large uveal melanomas with the gamma-knife

Abstract

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 treated 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 retention rate, and visual acuity. Results In 34 eyes (97%), local tumor control was achieved. The maximum apical tumor height decreased from a median of 9.1 mm (95% confidence interval [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 treatment ( P < 0.001, paired t test). Two eyes required enucleation (one radiation failure, one secondary glaucoma). The median visual acuity decreased from 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 alternative to enucleation in treating large uveal melanomas. The visual function may be preserved in selected cases.