Application of 5-ALA Fluorescence-guided Resection inPatients Suffering From High-grade Gliomas: A Report of30 Consecutive Cases and a Literature Review

The extent of resection seems a solid prognostic factor in patients with high-grade gliomas (HGGs). When administered orally, 5-aminolevulinic acid (5-ALA) is exclusively converted into protoporphyrin IX (PPIX) by malignant cells and detects, identifying contrast-enhancing glial lesions under 400 nm blue light. The authors thoroughly assess the efficacy, accuracy, and safety profile of 5-ALA-guided surgery toward the maximal resection of cranial HGGs.

Thirty consecutive patients with HGG adjacent to the corticospinal tract (CST) met our inclusion criteria in a single-arm retrospective study. Bilateral diffusion tensor imaging (DTI)-derived corticospinal tract (CST) tractography was employed using a 1.5 Tesla magnetic resonance imaging (MRI). Oral 5-ALA was ingested with a dose of 20 mg/kg 4 hours prior to operation and was applied to qualify the margins of the local resection cavity. The clinical and volumetric assessments were postoperatively conducted. The mean preoperative tumor volume on T1 contrast-enhanced MRI and fluid-attenuated inversion recovery (FLAIR) images was 16.8 cm3 and 47.6 cm3, respectively. Complete resection of contrast-enhanced lesions was yielded in 27 of 30 patients (90%). All patients improved postoperatively regarding motor deficits and or seizures. No new permanent neurological deficits were detected in the 3-month follow-up.

Fluorescence image-guided surgery (FIGS) using 5-ALA increases the extent of resection (EOR) with further surgical risks in eloquent regions when combined with multimodality visualization- functional mapping. It also provides pathological insights to visualize cranial HGGs and identify infiltration of functional fiber tracts.