Intraoperative Fluorescence-Guided Aspirate Tissue Monitoring of 5-ALA During Brain Tumor Surgery

Inclusion Criteria:- * Patient admitted to neurosurgery department for surgical resection of a suspected grade 3 or 4 glioma with 5-ALA (cases) * Patient admitted to neurosurgery department for surgical resection of a primary of secondary brain tumor with no 5-ALA (controls) * Patients aged 18 years old or older (all patients) * Informed consent obtained (all patients) Exclusion Criteria: * Patient belongs to the following vulnerable groups: children, pregnant, prisoners or intellectually disabled. * The participants are not randomized. Randomization is not conducted as the number of eligible patients is limited, subjecting to a long recruitment period that reciprocally increases the bias from uncontrollable (evolving) surgical techniques and adjunct treatments. * The patients are screened and informed of the study before the surgical operation and enrolled after verification of eligibility and written informed consent has been received. Potential study participants are identified from the clinic's planned or urgent surgeries list. The participants are contacted before the operation by the research staff and/or the physician responsible for the treatment. The participants are provided with written and oral information about the research and the time to consider their participation. Finally, the participants are asked for their informed consent and enrolled to the study.