Intraoperative functional neuro-OCT combined with optical tumor localization
This innovative project combines the expertise of the Department of Neurosurgery, the Medical Laser Center Lübeck gGmbH and the Institute of Biomedical Optics at the University of Lübeck. As part of the “Surgery of the Future funding initiative, German Cancer Aid is supporting this project over three years with a total of 581,000 euros. The focus is on the development of an intraoperative method that combines functional optical coherence tomography (OCT) with precise optical tumor localization.
The primary objective of surgical intervention for brain tumors within the central nervous system (CNS) is to achieve maximal resection, that is, the complete removal of the tumor while preserving critical functional areas of the brain. Scientific evidence has demonstrated a strong correlation between the extent of tumor resection and improved survival outcomes as well as a reduced risk of recurrence. However, it is imperative to acknowledge that extensive resection can concomitantly increase the risk of postoperative complications, including restrictions in movement, sensory function, speech, and vision.
Existing intraoperative technologies, including electrophysiology, the use of fluorescent dyes, and neuro-navigation, frequently reach their limits. This is particularly evident in cases of gliomas and metastases, where distinguishing between tumor tissue and vital brain tissue during surgery remains a significant challenge. Misinterpretations arising from electrophysiological measurements, such as false positive or negative signals, and technical limitations, including insufficient uptake of fluorescent dyes, contribute to the imprecision of these procedures.
Aim
Functional areas of the brain can be detected by an increasing blood flow to them during activity. In the FiOCT project, the application of functional MHz OCT is now to be used intraoperatively and developed further. The objective of this investigation is to examine the potential of real-time volumetric measurements of blood flow fluctuations subsequent to electrical stimuli to enhance the distinction between functional and non-functional brain tissue.
Background
The technological approach is optical coherence tomography (OCT), which is often described as “light ultrasound”. It enables microscopic insights into tissue. In recent years, OCT has proven to be a promising method for differentiating between tumorous and healthy brain tissue. It also allows high-resolution imaging of vessels using Doppler measurements, similar to Doppler echocardiography, which can be used to visualize blood flow.
In a previous project (“Neuro-OCT”, funded by the German Federal Ministry of Education and Research, ID: 13GW0227 A-C), the Lübeck research group developed the world's first MHz-OCT system, which operates at a speed of 1.6 million A-scans per second. This system was successfully integrated into a surgical microscope and provides high-resolution real-time mages.