Insular Gliomas. Experience in a Latin American Center and Assessment of Variables Related to Surgical Management and Prognosis

Abstract

Objective: To describe our experience in the resection of gliomas involving the insula and analyze the variables implicated in the management and prognosis of these tumors.

Methods: This retrospective, single-center, analytic study included a cohort of 83 patients who underwent surgery for insular gliomas by the same surgeon in a third-level Argentine center, in the period between 2010 and 2023. We analyzed the population's demographic, clinical, and radiologic features and surgical variables associated with postoperative results and prognosis using multivariate regression analysis.

Results: A total of 53 patients (54% men) were included, with a mean follow-up of 40.7 months. The mean age at surgery was 41 years (range, 21-73) and 66.1% corresponded to low-grade gliomas (LGGs). Seizures were the initial symptom in most cases. There was evidence of tumor extension over the insula to the temporal or/and frontal lobe in 64.2% of patients. An extent of resection >90% was achieved in 62.3% of cases (27% of gross total resection), with an average resected volume of 89.4%. Awake craniotomy was indicated in 47% of patients and intraoperative magnetic resonance imaging was performed in 24%. Recurrence was observed in 44% of patients, with a mean progression-free survival of 31 months (42 months in LGG and 10 months in high-grade glioma [HGG]). Nine patients underwent reoperation. By the time of 2 years, survival was 100% for LGG and 46% for HGG, whereas 4-year overall survival was 92% for patients with LGG and 15.4% for those with HGG.

Conclusions: Surgery for insular gliomas is a complex task that needs to be managed with adequate preoperative and intraoperative assessment to achieve maximum safe resection with low morbidity for better functional and oncologic outcomes. Adequate anatomic understanding, radiologic analysis, awake craniotomy, and cortical and subcortical mapping are paramount to pursue this aim.