Anatomical GPS-like system revolutionizes brain surgery

Canadian brain mapping and computerized imaging technology takes image-guided surgery to the next level to improve patient survival rates and quality of life.

Dr. Louis Collins

Professor, Neurology & Neurosurgery, McConnell Brain Imaging Center, Montreal Neurological Institute, and Biomedical Engineering, McGill University, Montréal, Québec

Associates and partners

Dr. T. Arbel, Electrical and Computer Engineering, McGill
Dr. J. Cooperstock, Electrical and Computer Engineering, McGill
Dr. R. F. Del Maestro, Neurology and Neurosurgery, McGill
Dr. D. Klein, Neurology and Neurosurgery, McGill
Dr. A. Olivier, Neurology and Neurosurgery, McGill
Dr. T. M. Peters, Electrical and Computer Engineering, Western University
Dr. K. P. Petrecca, Neurology and Neurosurgery, McGill
Dr. M. Petrides, Psychology, McGill
Canadian Institutes of Health Research
Natural Sciences and Engineering Research Council

Issue

Brain surgery to remove tumours and other lesions has an amazing potential to save lives. But it also risks damaging sensitive areas of the brain. This can leave patients unable to speak or to manage their lives on their own. With other advances in cancer treatment extending patient’s lives, doctors and patients must balance these quality-of-life issues when making the decision to try surgery.

Dr. Collins and his multidisciplinary team from the Montreal Neurological Institute, McGill and Western University have developed a new, low-cost, image-guided neurosurgery system (IGNS) that can better evaluate these difficult trade-offs and can enable surgeons to conduct more risky surgeries that will save lives.

Previous IGNS technologies have not fully lived up to their promise. The idea is that the medical team will collect images and information prior to the surgery to build a tailored roadmap of the patient’s brain for the surgeon to follow during the operation. However, most available commercial systems ignore the movement of brain tissue – areas of the brain can expand or shrink, moving by as much as three to five cm during surgery. When the tissue moves like this, the surgeon finds the “map” of the patient’s brain no longer useful for guidance during surgery.

Research

Dr. Collins and his team have developed a technique that combines pre-operative medical images from magnetic resonance and computed tomography with cognitive testing to create a virtual atlas of the patient’s bone structures, blood vessels and command centers of the brain. This initial “map” of the brain can be used to plan the surgery. The novelty of this project lies in the use of intra-operative ultrasound images to quickly update the “map” during surgery with new ultrasound snapshots and computer analysis that compares the new information collected against the original mapping. The result is like a “GPS” that can adapt to the movement in the brain and help guide the surgical team to their intended goal without encountering unwanted obstacles.

A CIHR Collaborative Health Research Projects grant, “Computational and statistical tools for image-guided neurosurgery of brain tumours” provided the support to make the technology work in a “non-linear” environment. This is when the equipment has to capture images and interpret information when the brain is deforming and changing shape in multiple directions.

“The feedback we get by working in a multidisciplinary team keeps the research ‘focused’,” says Dr. Collins. “By collaborating at each step with surgeons, we are always working on real-world problems. The whole idea for the image registration during the operation came from the surgeons telling us about the problems they faced with standard commercial IGNS systems. It’s also why we are working to present the images and data in layers – to keep from overwhelming the medical team with too much data at one time.”

Their Collaborative Health Research Projects grant from CIHR will now take the research to the next step – to testing the technique during actual surgeries.

Results

Ultimately, the aim is to get this new process into daily clinical use – making knowledge translation central to the success of the project.

“This is a technique that has the potential to save lives and to improve the quality of life of cancer survivors,” says Dr. Collins. “More patients with difficult cases will have the option to undergo surgery. Survival times should be longer, and the patient can enjoy more time before needing a repeat surgery. By using ultrasound images as the base, we can keep the cost to the health care system lower.”

Still at the pure research stage, Dr. Collins and his team are sharing their findings as widely as possible in order to improve the technology.

A database of patient-approved pre-operative and post-operative images is readily available to other researchers through the Internet. Images of the custom “phantoms” used in the research phase are also freely available, together with a recipe on how to construct them. The phantoms are used to stand-in for real patients during testing, and are made of materials that mimic the structure and consistency of the patient’s brain during scanning and practice surgery.