Gamma Knife Stereotactic Radiosurgery for Giant Intracranial Tumors - A Series of 70 Patients

Background and Objective: Surgery remains the primary option in large intracranial tumors, but significant number of patients may not be amenable for surgery. We explored the role of stereotactic radiosurgery as an alternative to external beam radiation therapy (EBRT) in such patients. Our study objective was to assess the clinicoradiological outcomes of large intracranial tumors (volume >= 20 cm(3)) managed with gamma knife radiosurgery (GKRS). Materials and Methods: This was a single-center, retrospective study conducted from January 2012 to December 2019. Patients with intracranial tumor volume >= 20 cm(3) who received GKRS and had a minimum of 12 months of follow-up were included. Clinical, radiological, and radiosurgical details and clinicoradiological outcomes of the patients were obtained and analyzed. Results: Seventy patients who had a pre-GKRS tumor volume >= 20 cm(3) with >12 months of follow-up were included. The mean age of the patients was 41.9 +/- 13.6 (range 11-75) years. Majority (97.1%) received GKRS in a single fraction. Mean pretreatment target volume was 31.9 +/- 15.1 cm(3). At a mean follow-up of 34.2 +/- 17.1 months, tumor control was achieved in 91.4% (n = 64) of the patients. Adverse radiation effects were observed in 11 (15.7%) patients, but were symptomatic in only one (1.4%) patient. Conclusion: The present series defines "large intracranial lesions" for GKRS and demonstrates excellent radiological and clinical outcomes in these patients. GKRS may be considered as the primary option in such large intracranial lesions in which surgery carries significant risk based on patient-related factors.