Indications of 5-Aminolevulinic Acid and Intraoperative MRI in Glioma Surgery: First Cases in Latin America in a Single Reference Center

Introduction: The improvement on the extent of resection (EOR) of gliomas with the combination of 5-aminolevulinic acid (5-ALA) and intraoperative magnetic resonance imaging (iMRI) has been demonstrated in previous studies. We present our results with the combined use of 5-ALA and iMRI for surgery of glial lesions.

Methods: 64 cases of intracranial gliomas who underwent image-guided surgery using 5-ALA with and without iMRI were reviewed. All patients underwent early postoperative MRI to evaluate the extent of resection (EOR). Other intra-operative techniques (awake surgery, electrophysiological stimulation and monitoring) were also performed according to tumor location.

Results: 18 tumors did not show intraoperative 5-ALA fluorescence (2 WHO-grade I, 14 WHO-grade II, 1 WHO-grade III and 1 WHO-grade IV) and 46 tumors did (3 WHO-grade II, 3 WHO-grade III, 40 WHO-grade IV). In 28 of the 46 5-ALA positive cases, a safe 5-ALA free resection was achieved. In 5-ALA negative cases, iMRI findings guided EOR, achieving complete resection in 11 cases. Complete resection was opted out in gliomas infiltrating eloquent areas.

Conclusions: The use of 5-ALA and iMRI showed improved results in glioma surgery, offering the safest maximal EOR. In 5-ALA positive cases (mostly high-grade), fluorescence was a more useful tool. In 5- ALA negative cases (mostly low-grade), iMRI was decisive to guide the extent of tumor resection.