SURG-60. Surgical implication of resecting medial temporal lobe in patients with temporal glioblastoma

Recent studies have evaluated the impact of extended resection beyond the enhancing component on survival outcomes. However, the clinical significance of resecting the medial temporal lobe beyond the enhancing lesion for temporal lobe glioblastoma are unknown. A retrospective review was conducted on 40 cases of temporal lobe glioblastoma that underwent surgical resection at Kobe University Hospital over a 10-year period from January 2014 to December 2023. All but three cases were treated with temozolomide-based radiochemotherapy, and at the time of recurrence, followed with the treatment of bevacizumab. Resection of the medial temporal lobe was defined as resection of the amygdala, hippocampus, and parahippocampal gyrus, and the effects on treatment outcomes, recurrence patterns, and complications were evaluated. The mean resection rate of contrast-enhancing lesions was 93.5%. Fifteen cases underwent resection of the medial temporal lobe, but no significant extension of overall survival or progression-free survival was observed. Regarding the type of recurrence, dissemination or distant recurrence was significantly more frequent in patients who underwent resection of the medial temporal lobe (7/11 cases, 63.6%; Fisher exact test, p=0.0046). Small deep infarction related with a perforating artery was observed in 4 of the 15 cases in which the medial temporal lobe was resected. Resection of the medial temporal lobe for temporal lobe glioblastoma did not clearly contribute to improving the treatment outcomes of patients. If tumor infiltration into the medial temporal lobe is suspected, resection should be performed while protecting the surrounding tissue through the pia mater and paying attention to perforating vessels.