Safety and Efficacy of Multisession Gamma Knife Radiosurgery for (Large Benign Intracranial Lesions > 3cm)

Background: Stereotactic radiosurgery is delivery of an ablative dose of ionizing radiation to a focused target with 3D localization to elicit a specific radiobiological response and sparing the surrounding normal brain tissue. Objective: to evaluate safety and efficacy of Gamma knife radiosurgery by volume staging of large benign intracranial lesions. Patients and methods: prospective cohort study is conducted at Saad Alwitry neuroscience hospital, gamma knife department between June 2017 to February 2021, 60 patients (25 case meningioma ,15 case vestibular schwannoma ,10 case arteriovenous malformation and 10 patients with pituitary macro-adenoma) having large lesions of >3cm were treated by multisession radiosurgery (2-3 sessions), time between sessions (24hr-6m), follow up time ranged from(6ms-3yr). Results: rate of growth control for meningioma, vestibular schawannoma, AVM and pituitary macro-adenoma was 76 %,53.3% ,30% and 60% while reduction in lesion size is 20%, 33.3%, 70% and 30% respectively and clinical improvement was 86.4% for meningioma ,52.6% for VS ,73.2% for AVM and 88% for PA and the complications reported were 15.2%. Conclusion: volume staged multisession GKSR is effective, safe and well tolerated with low morbidity modality for these large lesions.