Survival and complications following supra- and infratentorial brain metastasis resection

15-30% of primary cancers metastasise to the brain. Of these, 10-25% involve the posterior fossa. It remains unclear whether patients undergoing resection for infratentorial brain metastases experience poorer prognosis than those with supratentorial lesions. We compare the post-operative outcomes of these two groups.

We searched the electronic health records of all patients undergoing brain metastases resection at our regional neurosurgical centre between February 2014 and August 2019. Clinical data was collected on 85 consecutive patients (61 supratentorial, 24 infratentorial metastases). Outcome measures included overall survival, post-operative complications, and performance status. Patients were followed up until 21/04/2020.

Median post-operative survival of patients with supratentorial metastases was 323 days (95% CI 235-411), compared to 277 days (95% CI 195-359) for those with infratentorial metastases. These two groups experienced comparable survival (log rank = 0.276, p = 0.60) on univariate analysis. Infratentorial metastasis location was not associated with a change in survival using a Cox proportional hazards model incorporating age, sex and extracranial disease activity (HR = 1.39, 95% CI 0.777-2.486) (p = 0.27). However, neurological and non-neurological post-operative complications were more frequent in patients with infratentorial metastases (neurological = 21% vs 13%, non-neurological = 25% vs 2%, p = 0.002).

Patients with supra- and infratentorial metastases experienced comparable post-operative survival but posterior fossa metastasis location was associated with a 2.5 times higher risk of neurological and/or non-neurological post-operative complications. A better understanding of the precise indications for safe and effective surgical intervention for posterior fossa metastases is required.