Object: Data regarding the long-term efficacy of Gamma knife surgery on a large series of patients with low-grade gliomas is lacking. We aimed to review the outcome of patients with low-grade gliomas undergoing Gamma knife surgery at the Lars Leksell Gamma Knife Center at the University of Virginia to clarify its role in the management of these lesions.
Methods: A retrospective review of 49 patients treated between 1989 and 2003 was conducted. The median follow up was 63 months. Gamma knife surgery was generally performed for tumors in eloquent brain, residual tumor post-surgery or for late progression after surgery.
Results: Median clinical progression free survival was 44 months and median radiological progression free survival was 37 months. Five-year radiological progression free survival was 37% while clinical progression free survival was 41%. Mortality due to tumor progression occurred in 7 patients (14%). Complete radiological remission was seen in 14 patients (29%). Complications due to Gamma surgery were seen in 4 patients (8%). Of these, two resolved without sequelae, one required surgery for neurological decline and associated radiation induced changes, and one patient suffered a permanent neurological deficit from treatment.
Conclusion: Gamma knife radiosurgery is a safe treatment for low-grade gliomas and may be considered in patients with residual or recurrent disease.