Impact of Surgical Ventricular Entry on Survival Outcomes in IDH-Mutant Gliomas

BACKGROUND AND OBJECTIVES: Although some studies suggest ventricular entry (VE) is associated with complications and poor survival in glioblastoma, it remains unclear whether this association applies to isocitrate dehydrogenase (IDH)-mutant gliomas. This study evaluated the impact of VE on progression-free survival (PFS) and overall survival (OS) in these tumors. METHODS: A retrospective analysis of patients with supratentorial IDH-mutant gliomas, treated between 2006 and 2021 at the University of Pittsburgh Medical Center was performed. VE was identified through postoperative imaging review. RESULTS: A total of 231 patients were identified, with VE occurring in 32.9% (n = 76) of patients. During the study period, 64.9% of patients experienced disease progression, and 42.4% died. VE was associated with a higher rate of subependymal/ependymal enhancement (18.4% vs 3.2%, P < .001), leptomeningeal disease (6.6% vs 0.6%, P = .02) and, new distant foci development (18.4% vs 5.8% P = .006), shorter median OS ( P [log-rank] <0.0001), and shorter median PFS ( P < .0001). Multivariable analysis identified VE as an independent risk factor of decreased OS (HR: 2.1 [1.24-3.48], P = .005) and PFS (HR: 1.66 [1.13-2.44], P = .01), after adjusting for clinical, lesional, molecular factors, and subventricular zone contact. CONCLUSION: This study indicates that VE is associated with poor survival outcomes in IDH-mutant gliomas. These findings warrant prospective studies to better understand the risks, benefits, and mitigation strategies of VE in glioma surgery. Understanding the ependymal physical barrier as well as, cellular biological effects of VE, and its role in glioma tumorigenesis may serve as a basis for potential therapeutic targets in the future management of these patients.