Effect of Intraoperative Ventricular Opening on Recurrence Patterns Following Bis-Chloroethyl-Nitrosourea Wafer Implantation for Newly Diagnosed Glioblastoma.

Objective: To evaluate the effect of ventricular opening (VO) on recurrence patterns in patients with newly diagnosed glioblastoma (GBM) treated with bis-chloroethyl-nitrosourea (BCNU) wafer implantation.

Methods: This single-center retrospective study included 40 patients with newly diagnosed GBM who received BCNU wafer implantation after tumor resection between March 2013 and February 2022. The patients were categorized into two groups based on whether VO occurred during the GBM resection. While 18 patients had VO, 22 did not have VO. In cases with VO, the ventricular wall defect is closed with gelatin or oxidized regenerated cellulose and fibrin glue before BCNU wafer implantation. Recurrence patterns-classified as local, diffuse, distant, or multifocal-and time to recurrence were compared between patients with and without VO.

Results: The median follow-up period for the entire cohort was 32.2 months (interquartile range, 16.7-38 months). Median survival time was comparable between patients with VO and patients without VO (38 vs. 26 months, p=0.53). Recurrence occurred in 31/40 patients (77.5%) in entire cohort. The incidence of recurrence was comparable between patients with VO and patients without VO (14 [77.8%] vs. 17 [77.3%], p=1.0). No significant differences were seen between the two groups in time to recurrence (p=0.59) or recurrence patterns (p=0.35).

Conclusion: Ventricular opening during surgery with BCNU wafer implantation does not seem to influence the recurrence patterns. Ventricular opening does not induce distant recurrence if appropriate ventricular closure is performed.