This article is more than 5 years old. Information may no longer be current.
Real-time NBI optical diagnosis of diminutive colorectal polyps exceeds standards
Click Here to Manage Email Alerts
Real-time optical diagnosis for diminutive colorectal polyps using narrow-band imaging colonoscopy was shown to surpass clinical practice standards in a randomized trial, leading investigators to conclude that it may replace pathology diagnosis.
“We hypothesized that near focus, detailed viewing of the polyp pattern, using colonoscopies with push-button optical magnification, would improve the endoscopists’ confidence in the optical diagnosis, and thus, augment the implementation in clinical practice,” the researchers wrote.
Tonya Kaltenbach
To investigate accuracy and confidence levels in real-time optical vs. histopathological diagnosis of diminutive colorectal polyps, Tonya Kaltenbach, MD, from the Veterans Affairs Palo Alto, GI Endoscopy Unit and division of gastroenterology and hepatology, Stanford University School of Medicine, and colleagues, conducted the Veterans Affairs Colorectal Lesion Interpretation and Diagnosis (VALID) trial, a single-masked study of 558 patients undergoing routine high-definition colonoscopy at three institutions from March 2011 to May 2012. Five endoscopists who were trained in optical diagnosis participated.
The investigators randomly assigned 277 patients to optical diagnosis using near focus view (65x) and 281 using standard view (30x). Optical diagnosis was made using narrow-band imaging upon polyp detection (median diagnosis time, 14 seconds), confidence levels and surveillance interval recommendations were provided, and each polyp was submitted to a masked pathologist for analysis immediately after polypectomy. The primary endpoint was the proportion of accurate high-confidence optical diagnoses compared with pathology using near focus vs. standard view.
Overall, 1,309 polyps were detected, 74.5% of which were diminutive and 60% of which were neoplastic. High-confidence diagnoses were made with near focus view 85.1% (95% CI, 81.8%-88%) of the time compared with 72.6% (95% CI, 68.2%-76.7%) of the time with standard view (OR = 2.2; 95% CI, 1.6-3).
High-confidence accurate prediction was made for 75.3% (95% CI, 71.3%-78.9%) of all polyps using near focus view compared with 63.1% (95% CI, 58.5%-67.6%) using standard view.
Negative predictive values of high-confidence diagnoses were 96.4% (95% CI, 91.8%-98.8%) with near focus view and 92% (95% CI, 85.3%-96.3%) with standard focus view; sensitivity was 98.2% (95% CI, 95.5%-99.3%) and 95.2% (95% CI, 90.8%-97.6%), respectively.
There was 93.5% agreement with histopathology in surveillance intervals using near focus and 92.2% using standard view.
No postpolypectomy bleeding, coagulation syndrome, perforations or optical misdiagnosis of advanced histology occurred, and optical diagnosis did not significantly lengthen the time of the procedure.
“In conclusion, we provide evidence for a paradigm shift in the clinical practice of colonoscopy for colorectal cancer screening from universal pathology to real-time optical diagnosis of diminutive colorectal polyps,” the researchers wrote. “Using optical diagnosis, patients may have diminutive polyps diagnosed and removed at the time of the procedure, and the surveillance intervals immediately relayed, with significant potential in cost savings.” – by Adam Leitenberger
Disclosures: This study was partially funded by Olympus Medical America. Kaltenbach and two other researchers report they received research funding from Olympus Medical America and are consultants for Olympus Medical Systems Corporation.
Click Here to Manage Email Alerts