Raman effect comes to improve brain tumour surgery

Scientist have turned to Raman effect - named after Nobel Laureate Indian physicist C.V. Raman who discovered inelastic scattering of light 80 years ago - to solve complicated brain tumour surgeries.

A research by the Innovation Institute at Henry Ford Hospital shows promise for developing a new method to clearly identify cancerous tissue during surgery on one of the most common and deadliest types of brain tumour.

The findings offer improved outcome for those undergoing surgery to remove glioblastoma multiforme (GBM) - a tumour that attacks tissue around nerve cells in the brain.

While some tumours have clearly defined edges, or margins, that differentiate it from normal brain tissue, GBM margins are diffuse, blending into healthy tissue.

"This leaves neurosurgeons uncertain about successfully finding and removing the entire malignancy," said neurosurgeon and lead author Steven N. Kalkanis.

"Even with intensive treatment, including surgical removal of as much cancerous tissue as is currently possible combined with radiation and chemotherapy, the prognosis for GBM patients remains dismal," he added.

The Henry Ford team set out to develop a highly accurate, efficient and inexpensive tool to distinguish normal brain tissue from both GBM and necrotic (dead) tissue rapidly, in real time, in the operating room.

The researchers chose Raman spectroscopy, which measures scattered light to provide a wavelength 'signature' for the material being studied.

It was only very recently that the processing technology was able to be condensed into a tiny space.

The researchers decided to take full advantage of these advancements that lend themselves exceptionally well to a small, portable hand-held device, potentially yielding immediate results in real-time.

"When developed, it would be the first of its kind in the world for this sort of brain tumour application," said Kalkanis.

With this method, the researchers were able to distinguish the three types of tissue with up to 99.5 percent accuracy.

Future studies would focus on methods of collecting and identifying Raman 'signatures' from tissue with freeze artefact, said the study appeared in the Journal of Neuro-Oncology.