Low grade glioma (LGG) is a slowly evolving, highly invasive intrinsic brain tumor displaying only subtle tissue differences with the normal surrounding brain, hampering the attempts to visually discriminate tumor from normal brain, especially at the border interface. This makes anatomical borders hard to define during early maximal resection, which is the initial treatment strategy. Therefore, innovative, robust and easy-to-use real-time strategies for intra-operative detection and discrimination of (residual) LGG tumor tissue would strongly influence on-site, surgical decision making, enabling a maximal extent of resection. To validate this approach hyperspectral imaging (HSI) - using a SnapScan HSI-Camera (IMEC), stably mounted on an OPMI Pentero 900 microscope (Zeiss) - will be used to generate spectral imaging data patterns that discriminate in vivo low grade glioma tissue from normal brain both on the cortical and subcortical level.