Intra-axial Supratentorial Tumours Resection under Fluorescein Guidance with 560 nm Yellow Filter: A Cross-sectional Study

Abstract

Introduction: Excision of intra-axial tumours with maximal resection and minimal deficits is one of the intricate procedures in neurosurgery. Fluorescence-guided Surgery (FGS) helps in better identification of tumour tissue and allows Maximal Safe Resection (MSR) of high-grade brain tumours. Sodium fluorescein dye, when injected intravenously, gets concentrated in High-grade Glioma (HGG) tissue due to a disrupted Blood-Brain Barrier (BBB), thus aiding in MSR, Extent Of Resection (EOR), and Gross Total Resection (GTR). Aim: To assess the effectiveness of intraoperative use of sodium fluorescein in achieving MSR and GTR. Materials and Methods: This was a cross-sectional study conducted on 30 patients with HGG who underwent surgery between January 2021 and May 2023 at SDM College of Medical Sciences, Dharwad, Karnataka, India. Two groups of 15 patients each were divided into those operated with the use of Fluorescein Sodium (FS) and those without FS. FS was administered at a dose of 5 mg/kg at the time of craniotomy. The primary endpoint was the number of patients with Histopathological Examination (HPE)-confirmed HGGs showing no contrast-enhancing tumour in the immediate postoperative Magnetic Resonance Imaging (MRI). Secondary endpoints included residual tumours on postoperative MRI, Focal Neurological Deficits (FND), and FS-related toxicity. The association between FS status and recurrence at different treatment time points was assessed using the Pearson Chi-square test. Recurrence rates were compared in each FS group using the Cochran Q test. Statistical significance was set at a 5% level (p-value<0.05). Results: Homogeneous or heterogeneous yellow-green fluorescence was observed on the tumour tissue in all 15 patients (100%). Of the 15 patients where FS was used, two showed lesion recurrences at six months, and 13 showed recurrences at 12 months. Among the 15 patients where FS was not used, 11 showed recurrences at six months, and four showed recurrences at 12 months. This indicates that MSR, GTR, and EOR can be improved using FS intraoperatively during tumour resection. Conclusion: Based on the results, fluorescein dye with a 560 nm yellow filter under a highly illuminated microscope can help achieve better tumour resection with minimal injury to surrounding eloquent areas. It can be utilised as an ideal adjunct for tumour resection rather than with a microscope alone.

Keywords

• glioma
• gross total resection
• indocyanine green
• maximal safe resection
• sodium fluorescein