Estimation of Impact of American College of Radiology Recommendations on CT Colonography Reporting for Resection of High-Risk Adenoma Findings

Abstract

If computed tomographic colonography (CTC) rather than colonoscopy were used in this population, assuming 100% sensitivity of CTC for polyps > or =6 mm and ACR interpretation recommendations, then 29% of all patients and 33% of screening patients age > or =50 years with high-risk adenoma findings would be interpreted as normal, and an additional 18-23% of these groups with high-risk adenoma findings, respectively, could have polypectomy delayed at least 3 years.

Polyp Size Measurement at CT Colonography: What Do We Know and What Do We Need to Know?

“…For example, in the study by Lieberman et al ( 11 ), there was little change in prevalence of advanced neoplasia in polyps smaller than 6 mm when 6-mm polyps were downsized to 5 mm in a sensitivity analysis to study the effect of misclassifi cation of polyp size (an increase from 1.7% to 2.0%). Radiologists should be prepared for resistance from gastroenterologists to the concept of further raising the size threshold ( 74 ). Gastroenterologists will point to clinical data suggesting this approach is risky.…”

CT Colonography with Computer-aided Detection: Recognizing the Causes of False-Positive Reader Results

“…Having a 6-mm threshold increases falsepositive results, with a questionable benefit in cancer detection and long-term mortality. Current C-RADS recommendations stipulate that fewer than three 6-9-mm lesions can be managed with short-term surveillance after discussion with the patient rather than immediate endoscopy and biopsy (44)(45)(46)(47)(48)(49)(50). Additionally, there are limitations to the use of optical colonoscopy as the reference standard, with a reported miss rate for adenomas that are 6-9 mm and 1 cm or larger as high as 13% and 6%, respectively (58)(59)(60)(61).…”

“…C-RADS recommends that short-term surveillance be considered in patients with one or two 6-9-mm polyps and no additional risk factors, although there is continued debate and research relating to the appropriate polyp size and number to determine whether optical colon oscopy or a surveillance strategy should be recommended (42)(43)(44)(45)(46)(47)(48)(49)(50). In this size range, the likelihood that a lesion contains invasive carcinoma is less than 1% (42,43).…”

Screening for colorectal cancer: what fits best?

“…It was shown in studies that the sensitivity for detection of polyps with CTC drops with decreasing polyp size to 59% for polyps ≥5 mm [74]. Current American College of Radiology guidelines have recommended not reporting polyps smaller than 6 mm based on the fact that the risk of advanced histology in these diminutive polyps is low, but there is still a lack of consensus among the multiple disciplines over this controversial statement [75,76]. Based on these criteria, it is estimated that approximately 12.2-30% of all screening CTCs will be referred for colonoscopy [72,74].…”