Neurology Central

Optical coherence tomography could make brain tumor removal safer and more effective

Research released recently by a team at Johns Hopkins University (MD, USA) and published in Science Translational Medicine has highlighted the development of a novel imaging technology, utilizing optical coherence tomography (OCT), that may have the potential to provide surgeons with a color-coded map of a patient’s brain. The technique may enable safer removal of tumors, avoiding damage to crucial brain tissue.

Alfredo Quinones-Hinojosa (Johns Hopkins University) explained: “As a neurosurgeon, I’m in agony when I’m taking out a tumor. If I take out too little, the cancer could come back; too much, and the patient can be permanently disabled. We think OCT has strong potential for helping surgeons know exactly where to cut.”

OCT was first developed in the early 1990’s as a method for imaging the retina. The technique works using the same echolocation principle utilized by bats and ultrasound scanners, however is uses light waves as opposed to sound waves to create a higher-resolution image. Importantly and uniquely, OCT does not deliver ionizing radiation to patients as do X-ray, CT scans or PET scans.

Over the past decade many research groups have been working to extend the use of OCT to other organs beyond the eye. The team from Johns Hopkins University worked for 3 years to test the principle that the density of cancers will affect the way lightwaves are scattered and reflected, enabling a way to separate brain cancers from other tissues during surgery. Subsequently however, the team realised that the lack of myelin sheath on cancerous brain cells in comparison to healthy brain cells actually had a greater effect on OCT readings than density.

The discovery of the OCT ‘signature’ of brain cancer then enabled the research group to develop a computer algorithm to process the data and consequently generate a color-coded map of the brain with cancer highlighted in red and healthy tissue in green.

So far the method has been tested in human brain tissue removed during surgeries and in surgeries removing brain tumors from mice.

Looking forward, the team hope to begin clinical trials in patients soon. “We envision that the OCT would be aimed at the area being operated on, and the surgeon could look at a screen to get a continuously updated picture of where the cancer is — and isn’t,” Xingde Li (Johns Hopkins University), the lead author of the study commented.

Source: Johns Hopkins Medicine press release