Background:~The prognosis of glioblastoma patients highly depends on resection extent. Various strategies have been introduced to overcome the dilemma of intraoperative tumor identification.~In gastroenterology, confocal laser endomicroscopy (CLE) allows precise differentiation of tumor tissue from surrounding mucosa in various diseases. Combining high-definition white light endoscopy with CLE significantly increases sensitivity and specificity compared with the sole application of high-definition white light endoscopy.~CLE was recently introduced to neurosurgical applications. Although still in an early stage of clinical application, this technique has proven to be capable of differentiating various tumor entities in animal models as well as human tissue samples. CLE allows visualization of the underlying tissue on a microscopic scale, receiving information on the microstructure as well as cellular components. However, the clinical importance of this technique for its application in neurosurgery still needs to be demonstrated~Methods:~Intravenous injection dose of fluorescein sodium. For every operation the investigators plan to take pictures with the CONVIVO system before taking the material for standard frozen section and definitive histopathology. These pictures will be evaluated by a pathologist afterwards.~Objectives:~The primary objective of this trial is to demonstrate, that the CONVIVO system allows identification of tumor tissue. The secondary objectives are procedural aspects and handling issues covering the usability.
The prognosis of glioblastoma patients highly depends on resection extent. Various strategies have been introduced to overcome the dilemma of intraoperative tumor identification.~In gastroenterology, confocal laser endomicroscopy (CLE) allows precise differentiation of tumor tissue from surrounding mucosa in various diseases. Combining high-definition white light endoscopy with CLE significantly increases sensitivity and specificity compared with the sole application of high-definition white light endoscopy.~CLE was recently introduced to neurosurgical applications. Although still in an early stage of clinical application, this technique has proven to be capable of differentiating various tumor entities in animal models as well as human tissue samples. CLE allows visualization of the underlying tissue on a microscopic scale, receiving information on the microstructure as well as cellular components. However, the clinical importance of this technique for its application in neurosurgery will be demonstrated in this clinical trial.