LAUSR

The main goal of glioma surgery is to achieve maximal extent of resection (EOR) while preserving surrounding healthy brain tissue. However, determining tumor boundaries under the illumination of the surgical microscope might be challenging. In most of the cases, high-grade gliomas are easier to distinguish due to their typically necrotic and vascularized texture. On the other hand, determining the borders of low-grade gliomas (LGG) often requires additional procedures due to their diffuse and infiltrative behavior [1]. In order to target this issue, novel techniques, such as fluorescence-guided (5-aminolevulinic acid, 5-ALA) resection, neuronavigation, and intraoperative magnetic resonance imaging (IO-MRI) were introduced. Studies demonstrated that introduction of IO-MRI improved EOR, thus, overall survival in LGG patients, while decreasing mortality and recurrence rates [1–6]. Even with the combination of IO-MRI and neuronavigation, precise navigation under microscopic illumination might be an issue. Opening of arachnoid layers during