gms | German Medical Science

Objective: Intraoperative distinctions of brain tumors as well as determining the extent of resection are some of the most challenging factors during neurooncological surgery. Confocal laser endomicroscope (CLE) findings of removed tumour tissue were directly compared with intraoperative instantaneous sections by the neuropathologist in a blinded study. Here we present an update concerning low grade and high grade glioma differentiation with the CLE.

Methods: in total 42 tumour samples of 42 patients were examined. Of these 32 were diagnosed as high grade gliomas and 10 as low grade gliomas by final neuropathologist report. The imaging device comprises of a rigid endoscope with Hopkins-Rod lenses. The outer diameter is 5 mm and the length amounts 323 mm. The size of the circular scanning field covers 300 µm x 300 µm and the highest achievable resolution is 2 µm. The wavelength of the laser signal is red and scanning depth in 3D-mode is approximately 80 µm. The detected signal consists of reflection and scattering. The frame rate (2D) is almost 40 frames per second (real-time).

Results: Of the 32 high grade gliomas, 26 were diagnosed as such using CLE (81,2%), 30 by conventional intraoperative instantaneous sections (93,75). Of the 10 low grade gliomas 9 were diagnosed as such using CLE (90%), 10 by conventional intraoperative instantaneous sections (100%).

Conclusion: Our results prove that whilst CLE is a new and evolving technology, intraoperative differentiation between low grade and high grade gliomas is possible, making CLE an effective tool for quick intraoperative diagnostics.