With more than 15 million endoscope procedures done on patients each year in the US alone, scientists report evidence that a new version of these flexible instruments for diagnosing and treating disease shows promise for helping surgeons more completely remove cancerous tumors. The technology combines the endoscope with the phenomenon responsible for the eerie blue glow in the cooling water of nuclear reactors.

“The advance marries endoscopes to one of the newest and most exciting fields of medical imaging,” said lead researcher Zhen Cheng, Ph.D., of Stanford University. “Endoscopes are medical devices consisting of a long, thin, flexible tube of optical fibers fitted with a light and a video camera. The new approach expands the use of those fibers to include molecular-guided surgery to remove more of a cancerous tumor than is currently possible.”

Conventional endoscopic methods allow doctors to see inside the stomach or colon, for instance, and take biopsy samples for tests. The new imaging technology — called Cerenkov Luminescence Endoscopy (CLE) — has advantages over both traditional endoscopic and imaging techniques, like MRI, in also providing information about the functioning of the tissue.

CLE relies on the same phenomenon responsible for the soft blue glow in the cooling water in the core of nuclear power reactors. It results from interactions that occur when invisible particles from the nuclear reaction in the core zip through the water faster than the speed of light in water.

Cerenkov Luminescence Imaging (CLI) emerged just a few years ago when scientists discovered ways to harness the effect in devices that do not involve nuclear power reactors. Scientists found that CLI could dramatically improve the resolution of PET scans, enabling PET scanners to detect smaller objects than previously possible. The light used to reveal diseased tissue is visible light that can be detected with simple optical sensors. It also is compatible with commercially available optical imaging instruments and a wide selection of the nuclear imaging agents that doctors use to make structures in the body visible.

“One drawback, however, is that the weak blue light — unlike the X-rays in other medical scans — barely penetrates through deep tissues,” Cheng said. “This limits the usefulness of the technology in humans, where many tumors develop in areas deep inside the body. Our marriage of Cerenkov luminescence with the endoscope may be the perfect solution. With endoscopy, we can get close enough to the diseased tissue to take advantage of this technology.”