New imaging technology promises to safely remove brain tumors

For the following reasons, brain surgery is considered to be very difficult, for example, when removing a tumor, the neurosurgeon is like a tightrope. They try to remove the most tumors while maintaining the integrity of important brain tissue, but it is often impossible to distinguish between tumors and normal tissues with the eyes. Now, researchers at Johns Hopkins University report that they have developed an imaging technique that provides surgeons with a color-coded map of the patient's brain to show which areas have cancer and which ones .

Dr. Alfredo Quinones-Hinojosa, a professor of neurosurgery, neuroscience and oncology at the Johns Hopkins University School of Medicine and a clinical leader in the research team, said: As a neurosurgeon, I was very painful when I took out a tumor. of. If I take too little, the cancer will recur; if I take too much, the patient will be permanently disabled. We believe that optical coherence tomography has a strong potential to help surgeons know exactly where to cut.

Optical coherence tomography was first developed for retinal imaging in the early 1990s. It uses the same echolocation principle as bats and ultrasound scanners, but it uses light instead of sound waves. The resulting image has a higher resolution than the ultrasound. Unlike X-ray, CT scan or PET scan, optical coherence tomography does not introduce ionizing radiation to the patient.

Over the past decade, a global research team, including a professor of biomedical engineering, a team led by Dr. Xingde Li at Johns Hopkins University, has begun to develop and apply the technology to other organs besides the eye. on. Carmen Kut, a Ph.D. student at Dr. Li's lab, believes that it is possible to find ways to isolate brain tumors and other tissues during surgery by optical coherence tomography.

Working with Li, Quinones-Hinojosa and other colleagues, Kut first proposed the idea that the tumor density is relatively large, which has an effect on scattering and light reflection. This team spent three years building this technology. In the end, the researchers discovered a second characteristic of brain cancer cells that lacked the myelin sheath that wraps around healthy brain cells. This has a greater impact on optical coherence tomography reading than density.

When they discovered the characteristic optical coherence tomography markers of brain cancer, the team designed a computer program to process the optical coherence tomography data and immediately produced a color-coded map. The figure shows cancer in red and green in healthy tissue. Li said: We envision that optical coherence tomography can be applied to the surgical field, and surgeons can observe the screen to get a continuous update of the cancer location.

Kut said: The team has now systematically tested human brain tissue obtained during surgery and tumors removed from the mouse brain. The researchers hope to conduct clinical trials on patients in the summer of 2015.

Caption: The picture shows a self-made high-speed optical coherence tomography system for non-marking, real-time and quantitative images of human brain cancer tissue. Image credit: Science Translational Medicine; Kut C, Chaichana KL, Xi JF, Raza SM, Ye XB, McVeigh ER, Rodriguez FJ, Quinones-Hinojosa A, Li XD

Quinones-Hinojosa said: If future clinical trials are successful and the system can enter the market, this will be a major advancement in imaging technology in surgery. Ultrasound has a lower resolution than optical coherence tomography. Each MRI has a moving wheel that can be moved over the patient on the operating table. Such an instrument would cost millions of dollars. In the operating room, ultrasound takes an extra hour to get an image. By contrast, the research team is fortunate that optical coherence tomography systems cost less and cost hundreds of thousands of dollars.

Kut said: This system may be used to detect cancer in other parts of the body. She is investigating the use of optical coherence tomography combined with different imaging techniques to detect blood vessels so that they can be avoided during surgery .