Ruikang K. Wang, professor of bio-engineering and ophthalmology at University of Washington, recommends "Detection of intestinal dysplasia using angle-resolved low coherence interferometry," published in the Journal of Biomedical Optics in October.
A team at Duke University led by SPIE Fellow Adam Wax presents the results of a pilot, ex vivo study that uses a/LCI as a non-invasive way to detect pre-cancerous colon cells from the epithelium, or lining, of the colon.
Adam Wax (right) works on the prototype with a graduate student, Neil Terry.
The technique aims short bursts of light from the tip of an endoscope and could be an alternative to current biopsy techniques that require physicians to take many tissue samples, which can cause bleeding or perforation, or to use dyes and contrast agents for imaging.
The new optical biopsy technique allows for depth-resolved, label-free measurement of the average size and optical density of cell nuclei in epithelial tissue to assess the tissue health. a/LCI has previously been used clinically to identify the presence of dysplasia in Barrett's Esophagus patients undergoing routine surveillance.
Since about 85 percent of all cancers begin within the layers of the epithelium in various parts of the body, Wax believes the new system could also work in detecting cancers of the trachea, cervix, or bladder. In pre-cancerous cells, the nuclei are misshapen and larger than normal cells, and they scatter light in their own unique way, he says.
"The important thing for clinicians is being able to detect these changes in the nuclei in cells just below the surface, which might not be detected by just looking at the lining of the colon through an endoscope alone," Wax says.
The researchers reported a statistically significant correlation between increased average nuclear size, reduced nuclear density, and the presence of dysplasia at the basal layer of the epithelium, at a depth of 200 to 300 µm beneath the tissue surface.
"a/LCI was able to separate dysplastic from healthy tissues with a sensitivity of 92.9% (13/14), a specificity of 83.6% (56/67), and an overall accuracy of 85.2% (69/81)," they reported.
The new technique could be especially useful for people with inflammatory bowel disease, since they tend to have a higher incidence of dysplasia in the colon, says Christopher Mantyh, colorectal surgeon at Duke University Medical Center and co-author of the paper. "The old-fashioned techniques we use haven't changed in years. This could be a real game-changer in how we detect, characterize, and even treat precancerous or cancerous lesions."
Wax will discuss early cancer detection with coherence imaging at the 21 January Hot Topics session at SPIE Photonics West.
Source: Journal of Biomedical Optics 16, 106002 (2011); doi:10.1117/1.3631799.
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