Integration of 5-ALA fluorescence and intraoperative MRI in awake craniotomy for glioma resection: a six-year retrospective analysis

Gliomas are the most prevalent primary central nervous system tumors, characterized by their infiltrative growth patterns that complicate accurate surgical resection. Awake craniotomy (AC) enhances the extent of resection while minimizing neurological complications. This retrospective study analyzes the integration of 5-aminolevulinic acid (5-ALA) fluorescence-guided surgery and intraoperative magnetic resonance imaging (iMRI) during AC for glioma resection at a single center in Brazil. A retrospective analysis was conducted on 42 adult patients who underwent AC for gliomas with 5-ALA, with or without iMRI, between 2016 and 2022. The study comprehensively details the preoperative planning, intraoperative protocols, and postoperative outcomes. Patients were stratified into two groups based on using iMRI in conjunction with 5-ALA versus 5-ALA only. The mean age of the patients was 42 years (23-71) in the "5-ALA + iMRI" and 50 years (25-75) in the "5-ALA only" group. Glioblastoma was the most common high-grade glioma in both groups. In both groups, gross-total resection was achieved in 66.7% of patients. The "5-ALA only" resulted in a "5-ALA Free" rate of 51.9% of cases compared to 33.3% of the "5-ALA + iMRI" group (p = 1.0). Postoperative complications included transient and persistent deficits, with persistent aphasia in 20% of cases in the "5-ALA + iMRI" group and 18.5% in the "5-ALA only" group. Persistent hemiparesis appeared in 20% of the "5-ALA + iMRI" and 40.7% in the "5-ALA only" group. The median postoperative Karnofsky Performance Score was 90 in both groups, and the median length of hospital stay was 5.5 days and 5 days, respectively. The integration of 5-ALA and iMRI during AC enhances tumor delineation and maximizes the extent of resection, thereby improving surgical outcomes in glioma resection. Although both surgical approaches yield comparable clinical outcomes, the combined "5-ALA + iMRI" group offers specific intraoperative advantages, particularly in achieving complete resection in eloquent areas. Further multi-center studies with larger cohorts are warranted to validate these preliminary findings and explore the long-term benefits of these technologies.