Local control and results of leksell gamma knife therapy for the treatment of uveal melanoma

BACKGROUND AND OBJECTIVE: To evaluate the effectiveness of Leksell Gamma Knife stereotactic radiosurgery (Elekta, Stockholm, Sweden) with respect to local tumor control, visual acuity, and radiation side effects for uveal melanoma. PATIENTS AND METHODS: Retrospective, non-comparative case series of 23 patients with uveal melanoma treated with Gamma Knife stereotactic radiosurgery at Tufts Medical Center from 2000 to 2012. Patients received single-fraction stereotactic radiation therapy of 20-25 gray (Gy) (mean: 21.7 Gy), primarily at the 50% isodose line. Follow-up was 4 to 121 months (median: 41.5 months). Main outcome measures included local tumor control, metastasis, visual acuity, and complications of therapy. RESULTS: In 21 of 23 patients (91%), local control was achieved with a single session of Gamma Knife therapy. Both patients who did not have local control, as well as a third patient (three of 23, 13%) developed liver metastases. Visual acuity was 20/200 or better in eight of 23 patients (35%) at last follow-up. Radiation side effects severe enough to cause vision loss were present in 14 of 23 patients (61%). CONCLUSION: Gamma Knife therapy may be an effective alternative to enucleation in patients with uveal melanoma who are deemed less satisfactory candidates for brachytherapy or wish to avoid surgery.