New screening technologies improve detection of polyps during colonoscopy

The American College of Gastroenterology endorses colonoscopy as the preferred strategy for colorectal cancer screening because of its remarkable sensitivity in detecting and removing polyps before they become cancerous.

In a prospective study of 214 patients conducted at eight medical institutions in the United States, Dr. Douglas K. Rex of Indiana University Medical Center in Indianapolis, Dr. Jerome D. Waye of Mount Sinai Hospital in New York, and their research team evaluated the effectiveness of a new imaging device (Third Eye Retroscope ™) that provides a 180-degree retrograde view of the colon, while complementing the forward view of the standard colonoscope.

Retroscope Device Boosts Polyp Detection in the Colon

Researchers found that the retroscope, when combined with the standard colonoscope, significantly increased the detection of adenomas and other polyps. Investigators identified 203 polyps and 105 adenomas, which were removed with the standard colonoscope. The retroscope detected 13.3 percent additional polyps and 12.4 percent additional adenomas. All polyps were removed by standard colonoscope.

According to lead investigator Dr. Rex, “This new device has the potential to improve dramatically the detection of neoplasia during colonoscopy. Additional technical improvements are expected, which will make the device more effective and efficient.”

Study Finds Narrow Band Imaging Improves Detection of Flat Lesions in the Colon

In a separate analysis conducted at Valduce Hospital in Como, Italy, Dr. Franco Radaelli and his colleagues evaluated whether the use of narrow band imaging (NBI) versus white light during the withdrawal phase of colonoscopy could enhance the detection of flat or depressed colorectal lesions.

Two hundred fifteen patients, ages 50 to 69, who had a positive fecal occult blood test, underwent screening colonoscopy. The patients were randomized to a white light (107 patients) or narrow band imaging (108 patients) during the retraction phase – or withdrawal of the scope – of colonoscopy.

Researchers found narrow band imaging significantly improved the detection of flat or depressed lesions, but did not increase the adenoma detection rate. Twelve percent of patients with at least one flat or depressed lesion were detected by white light, compared to 23 percent using narrow band imaging.

“Narrow band imaging technique seems to increase the sensitivity of the exam in detecting non-polypoid lesions and deserves further evaluation,” says Dr. Radaelli.