STMO-08 INFLUENCE OF WIDE OPENING OF THE LATERAL VENTRICLE ON SURVIVAL FOR SUPRATENTORIAL GLIOBLASTOMA PATIENTS WITH RADIOTHERAPY AND CONCOMITANT TEMOZOLOMIDE-BASED CHEMOTHERAPY

BACKGROUND: The prognosis for glioblastoma (GBM) varies among patients. Ventricular opening during surgery has been reported as a prognostic factor for GBM patients, but the influence of ventricular opening itself on patient prognosis remains controversial. OBJECTIVE: Accumulating evidence has suggested that the subventricular zone (SVZ) harbors a neural stem cell niche and is associated with gliomagenesis. Several reports have hypothesized that aggressive characteristics of GBM in contact with the SVZ may be associated with the recruitment of neural stem cells from the SVZ that have abilities associated with invasive proliferation, leading to poor prognosis. We presumed that the degree of ventricular opening would correlate with the degree of SVZresection and with prognosis in GBM patients. This study therefore investigated whether the degree of ventricular opening correlates with prognosis in GBM patients treated with the standard protocol of chemo-radiotherapy. METHODS: Participants comprised 111 patients with newly diagnosed GBM who underwent surgery and postoperative radiotherapy and TMZ-based chemotherapy from 2005 to 2018. We classified 111 patients into “No ventricular opening” (NVO), “Ventricular opening, small” (VOS; distance < 21 mm) and “Ventricular opening, wide” (VOW; distance > 21 mm) groups. We evaluated the relationship between degree of ventricular opening and prognosis using survival analyses that included other clinicopathological factors. RESULTS: Log-rank testing revealed age, KPS, extent of resection, MGMT status, IDH1 mutation, and degree of ventricular opening correlated significantly with overall survival. Multivariate analysis identified the degree of ventricular opening (small vs. wide) as the most significant prognostic factor (hazard ratio = 3.674; p < 0.0001). CONCLUSIONS: We demonstrated that wide opening of the lateral ventricle (LV) contributes to longer survival compared with small opening among GBM patients. Our results indicate that wide opening of the LV may correlate with the removal of a larger proportion of tumor stem cells from the SVZ.