P16.20 * ANALYSIS OF GLIOBLASTOMA'S PERITUMORAL BRAIN ZONE USING BIPHOTONIC MICROSCOPY

Abstract

Glial tumors are primary tumors of the central nervous system. Gross total resection (GTR) of the tumor is the first step of its therapeutic management. Several techniques of per-operative analysis of the margin of the peritumoral brain zone (PBZ) have been developed in order to ensure a GTR of the tumor. We present here a new approach to the per-operative analysis of the PBZ using biphotonic microscopy analysis, a method allowing a fast and reproducible analysis of brain sample tissues. GB tumor zone, low-grade glioma and their respective PBZ were fixed on paraffine-embedded slices. These slices were analyzed using second harmonic generation microscopy (SHG) and two-photon excitation fluorescence (TPEF) microscopy. Data were collected and interpreted using a custom-wricen program with Labview, and compared to the histopathological diagnosis made by a certified neuropathologist. Each kind of brain tumor tissue and PBZ displayed a specific pattern in SHG and TPEF imaging. Also, distinction between tumor and PBZ was easy in SHG and TPEF analysis, allowing a clear vizualisation of the brain/tumor interface. SHG and TPEF imaging are fast and efficient methods allowing per-operative analysis of brain tumor tissue. The next step of our study will be to create an atlas of SHG and TPEF profile of the different brain tumors to allow direct per-operative analysis of PBZ without waiting for the pathological diagnosis, to ensure an optimal resection's quality.