Fluorescein-Guided Surgery for High-Grade Glioma Resection: An Intraoperative "Contrast-Enhancer"

Fluorescein sodium salt is widely used in medicine as fluorescein isothiocyanate and commonly named fluorescein (FL). This fluorophore has been used as a fluorescent tracer for many applications, especially in ophthalmic surgery. It was initially used in neuro-oncology in 1948 to control tumor resection margins. After a transient disuse, it has recently had a second spring with the development of dedicated filters for operating microscopes, although it is still under evaluation in clinical use. The aim of this study is to contribute to the investigation according to which FL-guided surgery for high-grade glioma (HGG) is related to better rates of gross total resection (GTR) and so to a better outcome.

We retrospectively analyzed 23 cases of patients with new diagnosis of HGG, operated on in our unit by intraoperative FL use with a filter system directly integrated into an operative microscope (group 1). Fluorescence was compared with histology by biopsies carried out both in the fluorescent areas and in the periphery of fluorescent areas. Group 1 was matched with a control group of 25 patients with HGG operated on in our unit during the last 2 years without FL guidance (group 2).

No side effects occurred related to FL. Histology and intraoperative neuronavigation showed strong correspondence with fluorescent and nonfluorescent areas. GTR rate was significantly higher in group 1 (82.6%) than in group 2 (52%).

Intraoperative fluorescein-guided surgery showed safety and feasibility. Our and other studies suggest an improvement of GTR rate in HGG than nonuse.