Gamma Knife Radiosurgery for Low-Grade Gliomas: Clinical Results at Long-Term Follow-Up on Tumor Control and Patients’ Quality of Life

Abstract Object Surgery represents first-line therapy for low-grade gliomas (LGGs), in some cases followed by radiotherapy (RT) and chemotherapy. Gamma Knife radiosurgery (GKRS) has gained more relevance in the management of these tumors. The aim of the study was to assess the efficacy and safety of GKRS for the treatment of LGGs. Methods Forty-two treatments, performed between 2001 and 2014 on 39 patients harboring LGGs, were included. Forty-eight percent of patients underwent previous surgery, while 20.5% previous RT. Mean tumor volume was 2.7 cm3 and median margin dose was 15 Gy. Results Mean follow-up (FU) was 60.5 months (range 6-164). Actuarial progression-free survival was at 1, 5 and 10 years were 74.9%, 52.8% and 39.1%, while actuarial overall survival was 97.4%, 94.6% and 91.8% at 9 months, 1 and 5 years respectively. Solid tumor control was achieved in 69.2% of patients, whereas cystic enlargement was recorded in 12.9% of cases. At last FU, volume reduction was recorded in 57.7% of cases and median volume decreased by 33.3%. Clinical improvement was observed in 52.4% of patients. Karnofsky Performance Status was improved in 15 patients (45.5%), unchanged in 17 (51.5%) and worsened in 1 (3%). Mean post-treatment scores of SF-36 domains did not significantly differ from those of Italian healthy population. Conclusions The study confirms safety and effectiveness of GKRS for LGGs in controlling tumor growth, relevantly improving patients overall and progression-free survival. Radiosurgery showed to improve patients’ functional performance and quality of life, optimizing their social functioning and minimizing disease-related psychological impact.