Zeiss Brain Tumor Research Award - Incorporation of Intraoperative Confocal Laser Endomicroscopy into the Routine Workflow of Brain Surgery

Introduction: Intraoperative confocal laser endomicroscopy (CLE) allows neurosurgeons to distinguish tumor tissue from normal brain parenchyma during surgery. We demonstrate the feasibility of incorporating CLE as a routine part of brain tumor surgery workflow.

Methods: A prospective study is underway to evaluate the use of CLE in the setting of brain tumor surgery. In all cases, the CLE probe (Convivo, Carl Zeiss Meditec AG) was introduced in the surgical field to acquire images at various stages of resection. This was followed by a real-time neuropathology assessment of tissue characteristics using a telepathology software platform (TSP; Zeiss Convivo In Vivo Pathology Suite, Carl Zeiss Meditec AG). CLE/TSP was employed alongside planned surgical technique.

Results: The CLE system was employed as a co-diagnostic tool in six consecutive cases at our institution. Recurrent glioblastoma was the most common histopathological diagnosis. Two cases involved minimally invasive approaches, one via an endoscopic transsphenoidal route for a sellar lesion, and one using a tubular retractor for a periventricular WHO grade 4 glioblastoma. For all transcranial approaches, intraoperative ultrasound was used. The surgical microscope was used in three cases, and the exoscope was used in two cases. In two cases, the use of CLE was combined with a 5-ALA fluorescence-guided resection. Intraoperative neurophysiological monitoring, including somatosensory evoked potentials (SSEPs), was employed in all cases. In none of the cases was it necessary to modify the planned surgical workflow, and integration of CLE technology alongside standard operating procedures and tools was seamless.

Conclusion : CLE can be readily adapted into the standard neurosurgical workflow for patients with brain tumors without the need for major procedural modifications, including in microscopic, endoscopic, and minimally invasive tubular approaches. With easy integration, this technology may eventually prove to be an asset in improving surgical outcomes and diagnostic efficiency.