In vivo characterization of FLIm signatures on the diffuse glioma in the brain cortical surface (Conference Presentation)

The cortex, the brain's outer layer, is densely packed with neurons essential for sensory perception, motor control, and cognitive functions. Label-free fluorescence lifetime imaging (FLIm) has been shown to accurately distinguish tumor infiltrative edges in normal white matter but has been less successful in differentiating diffuse glioma from normal cortex. This study aims to characterize the FLIm signatures of cortical tissue with and without tumor cells, considering factors such as functional area, tumor grade, tumor recurrence, and 5-ALA administration for surgical guidance. The study was conducted on 32 patients during open craniotomy procedures using a multispectral FLIm system. Phasor-based univariate and multivariate analyses, visualized with PaCMAP, showed distinct FLIm contrasts between tumor-infiltrated and normal cortex in 11/26 glioma patients. Multivariate analysis improved separability in 21/26 patients. At resection margins, 5/8 patients showed distinct FLIm signals. Tumor recurrence negatively affected separability, but FLIm signatures were consistent across patient anatomy.