The HyperProbe project aims to revolutionize neuronavigation in brain surgery by introducing a hyperspectral imaging approach for real-time quantitative assessment of cerebral tissue. This technology is designed to assist neurosurgeons in both optimizing the delineation of pathological areas compared to healthy tissue and identifying the functional borders around a specific lesion. In neurosurgery - particularly in the resection of gliomas and glioblastomas - it is crucial to distinguish between tumor and healthy brain tissue while preserving essential cerebral functions. Current neuronavigation approaches rely on brain mapping techniques, which involve brain stimulation to localize, identify, and assess cortical and subcortical functions. Various paradigms are employed intraoperatively, depending on the targeted brain regions. These include cognitive tasks in awake patients (e.g. for speech and visual functions) and electro-stimulation (e.g. for sensory and motor functions). Electrical stimulation can be performed through direct transcortical and/or subcortical stimulation with probes, as well as indirect stimulation via electrodes to monitor muscular responses. However, all these approaches have limitations, including varying degrees of invasiveness, lack of real-time quantitative data, and limited specificity and sensitivity.
Current imaging techniques used in neurosurgery also present several constraints. Some rely on static, preoperative assessments (e.g. MRI, PET-CT), while intraoperative modalities, such as fluorescence imaging, are primarily used for tumor visualization rather than functional assessment. In particular, fluorescence molecules help to identify the tumor by selectively accumulating a fluorescent molecule in tumor cells, which emit fluorescence under specific illumination. While this technique enhances tumor visualization with high specificity, it lacks sensitivity for detecting tumor infiltration and is not effective for low-grade gliomas. Therefore, it is inaccurate to state that fluorescence imaging has low specificity for cerebral functions, as it does not assess brain function at all.
Addressing these limitations requires advancements in clinical practice toward a functionally guided neuronavigation approach that provides neurosurgeons with real-time, quantitative, and accurate intraoperative information. The HyperProbe project will design, develop, and clinically validate a novel, all-optical, multifunctional imaging device capable of providing comprehensive characterization of cerebral tissue during surgery. This device will offer neurosurgeons unprecedented structural, pathological, and functional insights to enhance patient outcomes in neurosurgical procedures.
The project has the following objectives, all contributing to the goal of a novel device to transform neuronavigation during brain surgery and cortical activity stimulation:
1) Development of the hyperspectral imaging system - the HyperProbe (HP) - to map, monitor, and quantify biochemical compounds in brain tissue during neurosurgery and cortical activity stimulation.
2) Upgrading HP to a portable, cost-effective prototype suitable for use in operating rooms.
3) Characterization and validation of HP on optically-realistic brain tissue phantoms.
4) Development of artificial intelligence-based algorithms to identify biomarkers of brain activity for in vivo imaging with HP during brain surgery and cortical activity stimulation.
5) Clinically validating HP against existing surgical imaging techniques like fMRI.
6) Conduction of feasibility studies on the performances of the HP on patients during glioma surgery and multiple paradigms of stimulation of brain activity, as part of observational, proof-of-concept analysis.
The scientific objectives of the project are: (i) multi-disciplinary, merging engineering, physics, computer science, neurology, and neurosurgery; (ii) translational, transforming laboratory-based devices and technology into clinical instrumentation that can be used during brain surgery and in vivo cortical activity stimulation, and (iii) ground-breaking, with aiming to improve patient and surgical outcomes.
