The Effect of Gamma Knife Surgery on Uveal Melanoma

ABSTRACT

The optimal management of uveal melanoma is still a matter of controversy. To determine the effect of Gamma Knife surgery on patients with uveal melanoma, the authors reviewed the outcome of five operations performed between September 1993 and August 1996. The mean age of the patients was 60.7(range 42 to 76) years; the median follow-up period was 10 months, and four patients were followed up for more than 6 months. The mean tumor volume was 3442mm3(mean diameter 15.3mm) and all patients were irradiated with a mean maximum dose of 74Gy (range 60-80Gy), using a 50% isodose on the tumor margin. In one patient, the tumor disappeared completely 32 months after Gamma Knife surgery; because the tumor did not regress, one patient subsequently required enucleation, and two remained stable. During a mean follow-up period of 10 months, vision was preserved in two patients, but one went blind; in one, enucleation was performed because the tumor did not regress. These results suggest that in cases of uveal melanoma Gamma Knife surgery can effectively control local tumors, can spare the eyeball, and may prevent loss of vision.