Probe can distinguish cancer cells from healthy brain in surgery

The advance, from the Montreal Neurological Institute and Hospital (The Neuro), part of Montreal’s McGill University and the McGill University Health Centre, and Polytechnique Montréal, has led to the creation of a new probe that can be used during surgery for detecting cancer cells.

For the first time, the hand-held Raman spectroscopy probe enables surgeons to accurately detect virtually all invasive brain cancer cells in real time during surgery. The probe is claimed to be superior to existing technology and could set a new standard for successful brain cancer surgery.

‘Often it is impossible to visually distinguish cancer from normal brain, so invasive brain cancer cells frequently remain after surgery, leading to cancer recurrence and a worse prognosis,’ said Dr Kevin Petrecca, chief of neurosurgery and brain cancer researcher at The Neuro, and co-senior author of the study published in Science Translational Medicine . ‘Surgically minimising the number of cancer cells improves patient outcomes.’

Designed and developed in partnership with Dr Frédéric Leblond, Professor in Engineering Physics at Polytechnique Montréal, and co-senior author of the study, the probe technique uses laser technology to perform Raman spectroscopy, which measures light scattered from molecules and provides information about the chemical bonds which exist in the sample. ‘The emitted light provides a spectroscopic signal that can be interpreted to provide specific information about the molecular makeup of the interrogated tissue,’ Dr Leblond said in a statement. ‘The Raman spectroscopy probe has a greater than 92 per cent accuracy in identifying cancer cells that have invaded into normal brain.’

The Raman probe was tested on patients with grade 2, 3 and 4 gliomas, which are highly invasive brain cancers. ‘We showed that the probe is equally capable of detecting invasive cancer cells from all grades of invasive gliomas,’ said Dr Petrecca. ‘There is strong evidence that the extent of tumour removal affects prognosis for all grades of invasive gliomas.’

In order to show that the use of this system improves patient outcomes, a clinical trial at The Neuro will be launched for patients with newly diagnosed and recurrent glioblastoma. If these trials are positive, the probe will improve brain cancer surgeries and in turn extend survival times for brain cancer patients.

This work was supported by the Fonds de recherche du Québec-Nature et technologies, the Natural Sciences and Engineering Research Council of Canada and the Groupe de recherche en sciences et technologies biomédicales.