Screening endoscopy is widely accepted as today's standard of practice for detecting pre-cancerous and cancerous lesions of the colon. Yet, even with cutting-edge advances in high-definition resolution scopes, detection of flat or intraepithelial neoplasms (by their sheer nature) in general screening endoscopy procedures is difficult.
Pentax Medical's (Montvale, New Jersey) emerging confocal endomicroscopy technology, however, is showing great promise in one day erasing some of that difficulty.
Pentax' confocal breakthroughs fuse the world of endoscopy and confocal microscopy. To create confocal images, blue laser light is focused on the desired tissue via the distal end of an endoscope equipped with a special confocal optical unit.
Applied fluorescent materials are excited by laser lights which the confocal optical unit detects in an exactly defined horizontal level. This produces high-resolution microscopic structures down to the size of the cell nucleus.
Greg Calder, an advanced imaging specialist with Pentax, explained to Diagnostics & Imaging Week that the benefits of the confocal lens will benefit both physicians and patients. "With an accomplished user, you can examine more tissue than you would with a standard biopsy protocol. So [with this technology] you can just focus on the areas that have potential dysplasia, so the doctors are taking fewer biopsys, but in return, they are getting a better biopsy each time," he said.
Calder said that the scope of the system corresponds to that of a conventional video endoscope. This means that the basic operation of the endomicroscope is not a real challenge to any endoscopist. The system also has a touch screen monitor for the endomicroscopic image, a monitor for the endoscopic image, a video processor, an optical unit, and a confocal control unit.
"The examiners will see fewer biopsies, but there is a higher rate of detection of possibly cancerous lesions. A great deal of the study focus right now involves patients with Barrett's Esophagus," Calder told D&IW.
The Pentax system provides full-resolution laser scans comparable to conventional histology using up to 1000x magnification and a 0.7 micron limit of resolution and viewing capabilities of surface features to a depth of 250 microns. As the virtual optical sectioning continues deeper into the tissue, it permits identification of histological features typical of laminal propria blood vessels and cells, basement membrane integrity, connective tissue and inflammatory cells.
"This is potentially a game-changing technology," said Gary Falk, MD, professor of medicine in the department of gastroenterology and hepatology at the Cleveland Clinic (Cleveland). "The technology has considerable promise to potentially decrease the number of biopsies we obtain in the future."
Falk recently began exploring the Pentax confocal technology as a potential novel approach to surveillance of patients with Barrett's esophagus. Impressed with its potential after putting the technology to the test, Falk cautiously – yet optimistically – is hopeful for confocal technology despite an obvious "learning curve," since most gastroenterologists are trained to decipher diagnostic surface images rather than the histological type being provided by the confocal endomicroscope.
Another endoscopy opinion leader, William Brugge, MD, of Massachusetts General Hospital (Boston), shared Falk's enthusiasm for the potential of the confocal technology.
"We are seeing imaging details like we have never before," said Brugge. "We actually saw H. pylori in a live demonstration of confocal's capabilities. Certainly, we know those organisms are there, but we've never seen them live in a procedure with an endoscope before. It was amazing."
Brugge too cites the need for cautious optimism, but as experience is gained with the confocal technology, the potential future applications of the breakthrough imaging technology for looking beneath the surface have already impressively raised a number of eyebrows.
Pentax Medical is a division of Pentax of America, a consolidated subsidiary of HOYA. Pentax specializes in the development of video and fiber endoscopy equipment and computer technology/imaging products for diagnostic, therapeutic and research applications in the GI, ENT and pulmonary medical fields.