Introduction: low-grade astrocytomas represent a diverse group of primary brain tumors affecting young people. Gamma knife radiosurgery is a non-invasive therapeutic option for managing diffuse low-grade astrocytoma providing long-term tumor control and preventing debilitating treatment-related consequences, particularly for those in deep-seated structures or in critical locations.

Aim: evaluate the effectiveness, feasibility, and acute and subacute side effects of gamma knife radiosurgery in the management of patients with diffuse low-grade astrocytoma.

Methods: This non-randomized clinical trial was conducted on 68 patients with diffuse low-grade astrocytoma who were treated at a Gamma Knife Center, Nasser Institute, Cairo, Egypt.

Results: Tumor control after radiosurgery was achieved in 58 cases (15 of these tumors remained radiologically stable and 43 reduced in size) while 7 cases progressed (10.8% of cases). Gender, diagnosis either pathological or radiological, timing of GKRS, number of sessions and total tumor volume were found significantly affecting tumor response (p=0.038, p=0.001, p=0.010, p=0.008 and p=0.003 respectively). Acute toxicities included fatigue, alopecia, and headache and scalp erythema. Toxicities were minimal. No acute toxicities bigger than grade II of Common Terminology Criteria for Adverse Events v4.0 (CTCAE) were reported in treated patients. The progression free survival was 93.8% at 3 years, 90.8 % at 5 years an 89.2% at 8 years

Conclusions: Gamma Knife Radiosurgery offers patients with diffuse low-grade astrocytomas long lasting local tumour control with acceptable radiation toxicity, which improves patients' general health, PFS, functional performance and quality of life.