The impact of 5-aminolevulinic acid on extent of resection in newly diagnosed high grade gliomas: a systematic review and single institutional experience

Abstract

Background: Glioma surgery at its nascency relied predominantly on visual and tactile feedback for the removal of grossly abnormal tissue. This technique has inherent limitations in delineating infiltrative tumor from normal brain, thus limiting the ability to achieve a gross total resection consistently. Since extent of resection (EOR) is consistently correlated with measures of survival, fluorescence-guided surgery shows promise in improving our ability to treat high-grade gliomas (HGG). 5-Aminolevulinic acid (5-ALA) is a prodrug preferentially metabolized by glioma cells that allows direct, real-time visualization of pathologic tissue through fluorescence under blue light.

Objective: To report the relationship between 5-ALA and EOR in newly diagnosed HGG. To report our institutional experience including nuances of workflow.

Methods: The authors performed a systematic review of the available literature between 1998 and 2018 to isolate studies addressing the impact of fluorescence-guided surgery with 5-ALA on the EOR in newly diagnosed HGG. Search strategy was in adherence to the preferred reporting items for systematic reviews and meta-analyses methodology.

Results: Out of 741 unique articles, eight fulfilled our strict inclusion criteria. Fluorescence-guided resection led to greater EOR in all studies, with six demonstrating statistical significance (p < 0.05). Two studies additionally demonstrated statistically significant increase in progression-free survival in the 5-ALA groups.

Conclusions: 5-ALA has an unambiguously positive impact on improving EOR for newly diagnosed HGG. Since the nature of modern glioma surgery includes a complex arsenal of surgical adjuncts, 5-ALA is seldom examined in isolation and can be complemented by intraoperative MRI.

Keywords: 5-Aminolevulinic acid; Aminolevulinic acid; Extent of resection; Fluorescence-guided surgery; High-grade glioma.