Postoperative Air in the Cisterns or Ventricles Predicts Early Leptomeningeal Disease of Brain Metastases: A Retrospective Study.

Abstract

We investigated whether air in the cisterns or ventricles on postoperative computed tomography (CT) (reflecting the opening of the cerebrospinal fluid spaces during surgery) is a predictor of classical or nodular leptomeningeal disease (LMD) after resection of brain metastases. We retrospectively analyzed 73 patients who underwent gross total resection of brain metastases between 2012 and 2020. Patients with air in the cisterns or ventricles on postoperative day 1 CT were categorized into the air-positive group, whereas those without air in the cisterns or ventricles on postoperative day 1 CT were categorized into the air-negative group. The primary outcome was the occurrence of classical or nodular LMD (nLMD), which was assessed using survival analysis. There were 15 (21%) patients in the air-positive group and 58 (79%) in the air-negative group. The air-positive group exhibited significantly more cerebellar and ventricular contact lesions than the air-negative group. The 4-year rate of classical or nLMD was significantly higher in the air-positive group than in the air-negative group (67% vs. 33%, P < 0.001). Multivariate analysis identified air in the cisterns or ventricles on postoperative CT as the only significant predictor of classical or nLMD (P < 0.001). Postoperative air in the cisterns or ventricles can predict early classical or nodular leptomeningeal disease.