New Endoscopes Advance Cancer and Neoplasia Detection

An endoscopic imaging tool only one and a half millimeters in diameter shows the highest accuracy yet in detecting intraepithelial neoplasia in Barrett's esophagus (BE), according to a new study.

Researchers at the Mayo Clinic (Jacksonville, FL, USA) conducted a prospective, double-blind review of probe-based confocal laser endomicroscopy (pCLE) images of 40 sites of BE tissue, by using matching biopsies as the reference standard. A training set of 20 images with known histology was first reviewed to standardize image interpretation, followed by blinded review of 20 unknown images; 11 experts in BE imaging from four different endoscopy centers from the United States and Europe then evaluated the images. The main outcome measures were sensitivity, specificity, and agreement on pCLE based diagnosis of high-grade intraepithelial neoplasia or carcinoma.

The results showed that in the validation set, 11 cases had high-grade intraepithelial neoplasia or invasive carcinoma. The sensitivity for the diagnosis of neoplasia for the 11 endoscopists was 88%, and the specificity was 96%; there was substantial agreement on the pCLE diagnosis. However, endomicroscopists with prior pCLE experience had an overall sensitivity of 91%, and almost perfect agreement. According to the researchers, the results suggest that pCLE for the diagnosis of neoplasia in BE has very high accuracy and reliability. The study was published ahead of print on April 7, 2010, in Gastrointestinal Endoscopy.

"We can see detail that was unimagined 10 years ago,” said lead author gastroenterologist Michael Wallace, M.D. "With the newest systems, we can zoom in on a potential problem spot in the colon or esophagus with 1,000-fold magnification, leading to a day when we can perform virtual biopsies on patients -- meaning that we will be able to tell if a lesion is precancerous by looking at it, and if it isn't, we can leave it alone. Now we have to remove anything that looks even slightly suspicious.”

Confocal laser endomicroscopy is a new field of endoluminal imaging that offers extremely high magnification and resolution, approximating white light microscopy. The key feature of confocal microscopy is its ability to acquire in-focus images from selected depths, a process known as optical sectioning. Images are acquired point-by-point and reconstructed with a computer, allowing three-dimensional (3D) reconstructions of topologically complex objects. For interior imaging, the quality of the image is greatly enhanced over simple microscopy because image information from multiple depths in the specimen is not superimposed.

Related Links:
Mayo Clinic