Adaptive staged-dose Gamma Knife radiosurgery for the treatment of large brain metastases. Report of 40 consecutive cases and review of literature.

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 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. Adaptive staged-dose GammaKnife Radiosurgery (ASDGKRS) has shown to be a safe and effective treatment for large brain metastases. Methods: We retrospectively analyzed and compared with data from review of literature our series of patients treated with Adaptive staged-dose GammaKnife Radiosurgery for large brain metastases in ASST Grande Ospedale Metropolitano Niguarda, Milan - Italy, between February 2018 and May 2020. Results: Forty patients with large brain metastases underwent Adaptive staged-dose GammaKnife Radiosurgery, with median prescription dose of 12Gy and a median interval between stages of 30 days. At 3-months follow-up the survival rate was 75,0% with a local control rate of 100%. At 6-months 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; IC95%). The difference between baseline volume and 6-months follow-up volume was statistically significant. Conclusions: Adaptive staged-dose GammaKnife 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. [ABSTRACT FROM AUTHOR]