Combined Use of 5-Aminolevulinic Acid and Intraoperative Low-Field Magnetic Resonance Imaging in High-Grade Glioma Surgery.

Objective: We sought to assess the impact of 5-aminolevulinic acid (5-ALA) and low-field intraoperative magnetic resonance imaging (iMRI) on the extent of resection of high-grade gliomas (HGGs). Results are compared with those obtained when using 5-ALA and iMRI separately.

Methods: We retrospectively included patients with an HGG eligible for gross total resection (GTR) from January 2013 to January 2018. Patients were included according to 5-ALA surgical guidance (5A-group), iMRI (iMRI-group), or both (5A-iMRI-group). Surgical variables were registered, and presurgical and postsurgical radiologic and clinical variables were analyzed. Extent of resection ≥90%, complications, and new permanent neurologic deficit were compared using the chi-squared and analysis of variance tests. Other variables studied were mortality, average hospital stay, surgical time, and Karnofsky Performance Scale status before and after surgery.

Results: Most of the 118 procedures carried out were in men (59.2%). The mean age was 58 years. Sixty patients (50.8%) were operated on using exclusively 5-ALA assistance (5A-group), 19 (16.1%) using iMRI (iMRI-group), and 39 (33%) combining both techniques (5A-IMRI-group). There were no statistically significant differences among 3 groups regarding extent of resection ≥90% (73% 5A, 73.7% iMRI, 71.8% 5A-iMRI, P = 0.94); complication rates (18.3% 5A, 5.3% iMRI, 7.7% 5A-iMRI, P = 0.17); new or worsening of preexisting neurologic deficit at 1-month follow-up (13.3% 5A, 10.5% iMRI, 15.4% 5A-iMRI, P = 0.26); average hospital stay in days (9.5 5A, 6.4 iMRI, 7.6 5A-iMRI, P = 0.18); Karnofsky Performance Scale; nor surgical time in minutes (212.4 5A, 187.9 iMRI, 201.4 5A-iMRI, P = 0.13).

Conclusions: In our experience, combined use of iMRI and 5-ALA does not improve the studied variables when compared with those technologies when used separately, even though a slight tendency of a superior effectiveness is observed when using iMRI individually.