Hypofractionated Gamma Knife Radiosurgery: Institutional Experience on Benign and Malignant Intracranial Tumors

Abstract

Background/aim: We investigated the treatment outcomes and complications associated with hypofractionated GKRS for the treatment of benign and malignant intracranial tumors.

Patients and methods: Patients with intracranial tumors not candidate or refusing surgery were evaluated to assess eligibility to undergo hypofractionated Gamma Knife radiosurgery (GKRS). Targeted volumes were calculated using the GammaPlan^® workstation, and GKRS protocols were delivered with 3 or 5 daily fractions and a maximal total dose of 25 Gy. The thermoplastic mask was used to immobilize the patient's head without pin-based fixation frames.

Results: A total of 41 patients, affected with 6 different histologies, were treated and followed-up for a median of 12 months (range=4-24 months). Meningiomas were the most common tumors (33, 80.5%), followed by brain metastases (4, 9.7%). At last follow-up, 33 patients (80.5%) had stable disease, 8 tumor regression (19.5%), and 0 tumor progression. No acute radiation toxicity was observed. Death was reported in 3 patients (7.3%) due to malignant tumor progression.

Conclusion: Our hypofractionated GKRS protocol proved to be effective and safe in the treatment of patients with benign and malignant intracranial tumors. Local tumor control was achieved in all patients, with 8 patients showing tumor regression and no cases of acute radiation toxicity.

Keywords: Brain tumor; Gamma knife radiosurgery; brain metastases; fractionation; hypofractionated radiosurgery; meningioma.