Fig. 2.

FLIm-based assessment of 5 GBM resection margins (M1 – M5) from one patient. (a) 5-ALA-induced PpIX visible fluorescence images of the surgical FOV as seen with the surgical microscope. The dashed circles indicate the area where FLIm measurements and biopsies were collected. (b) Overlay of the average fluorescence lifetime maps on the surgical FOV for the NAD(P)H channel and (c) PpIX channel. (d) Representative H&E staining images from the corresponding margin at 400× magnification, white arrowheads highlight the tumor cell density of each margin. Black arrowheads in M2 indicate the presence of neurons. (e) Phasor plot representation of the fluorescence decays for each margin in the NAD(P)H channel and (f) PpIX channel. (g) Summary of tissue type and degree of tumor cellularity according to the neuropathology evaluation.