Canadian researchers develop multimodal optical spectroscopy probe

It was in 2015 that scientists at Polytechnique Montréal, the University of Montreal Hospital Research Center (CRCHUM), the Montreal Neurological Institute and Hospital (The Neuro), McGill University, and the MUHC developed a hand-held Raman spectroscopy probe allowing surgeons to accurately detect virtually all brain cancer cells in real time during surgery.

Schematic depiction of the probe being used to interrogate brain tissue during surgery. The image shows a photograph of the probe held by a surgeon, Raman spectral associated with normal brain and cancer, as well as a magnetic resonance image (MRI) of a brain cancer patient with the red area representing the tumor. Photo credit: Frédéric Leblond, Kevin Petrecca

Today, the research team has announced that they have perfected the invention and design a new and improved device. This probe offers improved accuracy, sensitivity and specificity when it comes to detecting not only brain cancer cells but colon, lung and skin cancer cells as well.

In intraoperative testing, the multimodal optical spectroscopy probe detected cancer cells with nearly 100 per cent sensitivity.

“The probe we’ve designed enables detection of nearly 100 per cent of cancer cells in the brain,” explains Dr. Frédéric Leblond, Professor of Engineering Physics at Polytechnique Montréal and a research fellow at the University of Montreal Hospital Research Centre (CRCHUM). “This is a very important advance. We’ve also been able to demonstrate the effectiveness of our technology in treating other forms of cancer. This means that more patients will benefit from better diagnosis, more effective treatment, and lower risk of recurrence.”

Surgeons can use this system during a procedure to detect cancer cells in real time.

“A technology with extremely high accuracy is necessary, since surgeons will be using this information to help determine if tissues contain cancer cells or not. An important feature of this device is its broad applicability. We found that it effectively detects multiple cancer types, including brain, lung, colon, and skin cancers,” concludes Dr. Petrecca, who is Chief of Neurosurgery, a brain cancer researcher, and holder of the William Feindel Chair in Neuro-Oncology at the Neuro.

The new probe version is multimodal and also uses intrinsic fluorescence spectroscopy to interpret the metabolic composition of the cells, as well as diffuse reflectance spectroscopy to analyze intrinsic tissue absorption in patients.

During recent testing on 15 other brain surgery patients, sequential use of these high-sensitivity spectroscopy techniques — integrated into a single sensor coupled with a detection system, in combination with stimulating lasers, a highly sensitive camera, and a spectrometer — the surgeon benefited from molecular imaging that provided never-before-seen accuracy, with cancer detection sensitivity improved by about 10 per cent compared with the first-generation probe.

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