Transoperative Magnetic Resonance Imaging in Awake Glioma Surgery: Experience in a Latin American Tertiary-Level Center.

OBJECTIVE: Analyze the usefulness, efficacy, and safety of transoperative magnetic resonance imaging (tMRI) in glioma surgery in awake patients. METHODS: Retrospective, single-center, analytical study of a cohort of patients who underwent awake surgery for gliomas by the same surgeon in a third-level Argentine center, in the period between 2012 and 2022. Only patients with pathology-confirmed gliomas, with 6-month follow-up, who had preoperative and postoperative volumetric magnetic resonance imaging, were included in this sample. Subsequently, we analyzed which patients received surgery with the tMRI protocol and the results using multivariate regression analysis. RESULTS: A total of 71 patients were included. A tMRI study was performed on 22 (31%) of these patients. The use of tMRI increased the percentage of resection by 20% (P = 0.03), thereby increasing the possibility of gross total resection. However, using tMRI significantly extended surgical time by 84 minutes (P < 0.001). In 55% of the patients in whom tMRI was performed, the resection was continued after it. The use of tMRI did not increase the rate of infections or the development of surgically associated neurological deficits in the long term, despite the fact that 47% of the patients showed the development of a new deficit or worsening of a previous one during the intraoperative period. CONCLUSIONS: The use of tMRI in awake glioma surgery proved to be a safe tool that contributes to increasing the degree of tumor resection, compared to the use of neurophysiological mapping and neuronavigation, at the expense of increased surgical times and costs. We consider tMRI in awake glioma surgery should be used in properly selected cases.

"Next Door" intraoperative magnetic resonance imaging for awake craniotomy: Preliminary experience and technical note.

BACKGROUND: During glioma surgery "maximal safe resection" must be the main goal. Intraoperative magnetic resonance imaging (iMRI) associated with awake craniotomy (AC) is a valuable tool to achieve this objective. In this article, AC with a "next-door" iMRI concept is described in a stepwise protocol. METHODS: This is a retrospective analysis of 18 patients submitted to AC using iMRI; a stepwise protocol is also discussed. RESULTS: The mean age was 41.7 years. Hemiparesis, aphasia, and seizures were the main initial symptoms of the patients. Sixty-six percent of the tumors were located in the left hemisphere. All tumors were near or within eloquent areas. Fifty-three percent of the cases were glioblastomas multiforme and 47% of the patients had low grade gliomas. The mean surgical time and iMRI time were 4 h 4 min and 30 min, respectively. New resection was performed in 33% after iMRI. Extent of resection (EOR) higher than 95% was possible in 66.7% of the patients. The main reason of EOR lower than 95% was positive mapping of eloquent areas (6 patients). Eighty percent of the patients experienced improvement of their deficits immediately after the surgery or had a stable clinical status whereas 20% had neurological deterioration, however, all of them improved after 30 days. CONCLUSION: AC associated with "next-door" iMRI is a complex procedure, but if performed using a meticulous technique, it may improve the overall tumor resection and safety of the patients.