Adaptive Staged-Dose Gamma Knife Radiosurgery for the Treatment of Large Brain Metastases: Report of 40 Consecutive Cases and Analysis of Literature.

ABSTRACT

Background: Brain metastases are the most common brain tumors, being one of the most frequent neurological complications of systemic cancer and an important cause of morbidity and mortality. Stereotactic radiosurgery is efficacious and safe in the treatment of brain metastases, with good local control rates and low adverse effects rate. Large brain metastases present some issues in balancing local control and treatment-related toxicity. Objective: Demonstrating adaptive staged-dose Gamma Knife radiosurgery (ASD-GKRS) being a safe and effective treatment for large brain metastases. Materials and Methods: We retrospectively analyzed our series of patients treated with two-stage Gamma Knife radiosurgery for large brain metastases in [BLINDED], between February 2018 and May 2020. Results: Forty patients with large brain metastases underwent adaptive staged-dose Gamma Knife radiosurgery, with median prescription dose of 12 Gy and a median interval between stages of 30 days. At three-month follow-up, the survival rate was 75.0% with a local control rate of 100%. At six-month follow-up, the survival rate was 75.0% with a local control rate of 96.7%. The mean volume reduction was 21.81 cm3 (16.76-26.86; 95% CI). The difference between baseline volume and six-month follow-up volume was statistically significant. Conclusions: Adaptive staged-dose Gamma Knife radiosurgery is a safe, non-invasive and effective treatment for brain metastases, with a low rate of side effects. Large prospective trials are needed to strengthen data obtained about the effectiveness and safety of this technique in managing large brain metastases.