Ventricular entry and postoperative leptomeningeal metastasis after resection of supratentorial high-grade glioma

OBJECTIVE: Ventricular entry (VE) during resection can maximize high-grade glioma (HGG) resection, but it remains unclear whether tumor contiguity to the ventricles or VE increases the risk of leptomeningeal metastasis (LM) and/or worsens overall survival (OS). METHODS: To clarify the role of VE and tumor location in LM incidence and OS, the authors retrospectively reviewed the charts of patients who underwent their first resection of supratentorial HGG at The University of Texas MD Anderson Cancer Center between 1993 and 2021. OS and time to LM diagnosis were estimated using the Kaplan-Meier method; their associations with patient and treatment variables, including the tumor proximity to the ventricle, were assessed via Cox regression analysis. RESULTS: The authors identified 884 patients: 390 (44%) had VE and 444 (50%) had ependymal contact (EC) tumors. Eighty-two percent of patients with VE had EC, while only 25% of those without VE had EC (p < 0.0001). On multivariate analysis, VE did not significantly predict LM (hazard ratio [HR] [95% CI] 1.32 [0.57-3.04], p = 0.520) or OS (HR 1.03 [0.87-1.22], p = 0.744). However, EC significantly increased LM risk (HR 3.97 [1.43-11.01], p = 0.008) and worsened OS (HR 1.33 [1.1-1.6], p = 0.003). Although patients with VE had an overall lower complete resection rate compared to those without VE (63% vs 72%, p = 0.005), VE improved the extent of resection among EC tumors with 58% having complete resection (vs 47% of EC tumors without VE). CONCLUSIONS: Tumors with EC predict higher LM risk and shorter OS, while VE during resection does not increase LM risk or worsen OS. Surgeons can use VE to maximize resection of supratentorial HGGs without increasing the risk of subsequent LM.