Safety and Efficacy of Intraoperative MRI for Maximizing Extent of Resection of Low and High Grade Gliomas: An Institutional Experience

Introduction: Gliomas comprise 25% of primary CNS tumors and 80% of all malignant CNS tumors. Extent of resection (EOR) of gliomas has proved a meaningful prognostic factor in median survival, time to progression, and post-operative complications. Intraoperative MRI (iMRI) has proven to be a widely popular instrument that maximizes EOR without significantly affecting surgical and functional outcomes. Here, we evaluate our institutional experience with iMRI resection of gliomas while assessing surgical outcomes, including postoperative neurologic deficits, length of stay and hospital readmissions.

Methods: All craniotomies for glioma resection in patients >18 years of age performed at our tertiary care hospital from January 1, 2010 through December 31, 2021 were included. IRB approval was obtained from our institution prior to data collection.

Results: 49 patients underwent iMRI resection, 29 of which were male. Mean age was 29.41 years, ranging from 18 to 59. Tumor location was lobar in 53% of patients, insular in 18%, multi-lobar in 16%, and other (thalamic, hypothalamic, ventricular,pineal, ) in 14%. 39% of patients required more than one iMRI scan. GTR was achieved in 65% and near total resection in 8% of patients. A new onset neurological deficit or seizure was found in 39% of the patients in the immediate postoperative period, but only in 18% at last follow up. The majority of postoperative events occurred after resection of multi-lobar or deep lesions. Only 12% of patients had an extended LOS (> 7 days). 14% of patients had a hospital readmission within 30 days after initial surgery, with an average LOS of 1.67 days. Mean follow up was 3.07 years post-operatively. Recurrence was found in 26% of patients at last follow up. A greater number of iMRIs was significantly correlated with a GTR without affecting postoperative outcomes (p < 0.022). Additionally, history of prior craniotomy was correlated with a higher number if iMRIs (p < 0.033).

Conclusion : Utilization of iMRI allowed for maximization of EOR while minimizing long-term postoperative deficits, extended LOS and 30 day hospital readmissions in our patient population.