Use of Fluorescence in Gliomas

Overview

During brain tumor surgery, it can be difficult for surgeons to distinguish between tumor tissue and healthy brain tissue. To address this challenge, fluorescent agents such as sodium fluorescein or 5-ALA are sometimes used. These substances cause the tumor to "glow" under specific lighting conditions, making it easier to visualize. This study retrospectively analyzes medical records of patients treated at the University Hospital of Alessandria between June 2023 and March 2024. It compares surgeries performed with these fluorescent agents to those performed without them, in order to determine whether fluorescence-guided surgery leads to a higher rate of complete tumor removal (gross total resection), as confirmed by post-operative MRI scans. The aim is to evaluate how the use of fluorescent dyes (fluorochromes) influences surgical outcomes in patients with high-grade gliomas (aggressive brain tumors). The study will also assess the impact of these tools on operative time, patient safety, and the overall recovery process.

High-grade gliomas are aggressive central nervous system tumors characterized by rapid growth and significant infiltration of the surrounding brain tissue. According to the European Association of Neuro-Oncology (EANO) guidelines, the standard of care involves a multimodal approach including surgery, radiotherapy, and chemotherapy. A key surgical goal is achieving Gross Total Resection (GTR), which is often limited by the difficulty of distinguishing tumor margins from functional brain structures. Fluorescence-guided surgery (FGS), using fluorochromes such as sodium fluorescein (SF) and 5-aminolevulinic acid (5-ALA), has emerged as a valuable tool to enhance intraoperative tumor visualization. This is a retrospective, observational, single-center study conducted at the Neurosurgery Unit of the Azienda Ospedaliero-Universitaria "SS Antonio e Biagio e Cesare Arrigo" in Alessandria. The primary objective is to evaluate the impact of fluorescence use on the extent of resection (EOR) in patients undergoing surgery for high-grade gliomas. The study compares surgical outcomes between procedures performed with and without the use of fluorescent tracers. The study includes all patients who underwent surgery for suspected high-grade glioma (ICD-9 codes 191-191.9) between June 2023 and March 2024. Data are retrospectively extracted from electronic medical records, histopathological reports, surgical logs, and discharge summaries. The extent of resection is assessed through comparative analysis of preoperative and postoperative magnetic resonance imaging (MRI) scans. Secondary endpoints include: Characterization of epidemiological and clinical profiles, Comparison of preoperative and postoperative neurological status, Assessment of surgical safety and operative time,Identification of adverse effects and progression-free survival (PFS). Descriptive statistics are used to summarize patient characteristics. Continuous variables are expressed as mean (standard deviation) or median (interquartile range), while categorical variables are presented as frequencies and percentages. Univariate analyses (Chi-square test, Fisher's exact test, or ANOVA) are performed to identify covariates for subsequent multivariate regression models. Statistical significance is set at p ≤ 0.05. Data management is conducted using the REDCap (Research Electronic Data Capture) platform, ensuring compliance with GDPR and Italian data protection regulations.