Outcomes of surgical treatment of periventricular IDH-wildtype glioblastoma

Opening the wall of the lateral ventricle is one of the techniques during the removal of glioblastoma due to a number of biological and topographic-anatomical features. One of these features is the presence of the subventricular zone and the contact of glioblastoma with it. The purpose was to study the characteristics of contact with the ventricles in patients with IDH-wildtype grade 4 glioblastoma, the results of surgical treatment, and survival. Materials and Methods: The study included 40 patients with newly diagnosed IDH-wildtype grade 4 glioblastoma. All patients underwent microsurgical resection. Radicality staging was carried out using RANO criteria (2023). The presence of contact of the contrasted and non-contrasted parts of the tumor with the lateral ventricles and the type of tumor growth were assessed. The fact of opening the lateral ventricle was recorded. The survival was estimated by means of the Kaplan-Meier method. Survival analysis was performed using the Cox regression method. Results: The median overall survival was 10 months (Q15.0; Q313.5). The first stage of the study was an analysis of a number of factors (type of tumor growth and degree of resection according to RANO criteria) that may affect survival. It was made to assess the homogeneity of patient groups depending on the type of contact of the tumor with the wall of the lateral ventricle and depending on the presence of an opening of the ventricular wall. As a result, a fairly homogeneous cohort of patients was obtained in which the above factors did not affect survival and, thus, their influence on the results was excluded. The next step was to evaluate the survival function depending on the opening of the lateral ventricle and depending on the contact with the ventricles using the Kaplan-Meier method and survival analysis by means of the multivariate Cox regression method. Tumor contact with the ventricle (p=0.896) and opening of the lateral ventricle (p=0.375) did not have a significant effect on survival. Differences assessed using the likelihood-ratio test were not statistically significant (p= 0.603). Conclusion: IDH-wildtype glioblastoma tends to grow from the periventricular zone, which is its characteristic feature. This fact does not have a significant impact on the outcome of surgical treatment. Notably, opening the lateral ventricle can be regarded as a safe marker for more complete resection of glioblastoma.