Pickhardt Perry J, Correale Loredana, Hassan Cesare
Department of Radiology, University of Wisconsin School of Medicine & Public Health, E3/311 Clinical Science Center, 600 Highland Ave, Madison, WI 53792-3252.
im3D Medical Imaging Laboratory, Turin, Italy.
AJR Am J Roentgenol. 2019 Jul;213(1):W1-W8. doi: 10.2214/AJR.18.20686. Epub 2019 Apr 11.
The purpose of this study is to evaluate factors affecting the positive predictive value (PPV) for detecting colorectal lesions at CT colonography (CTC), using optical colonoscopy (OC) as the reference standard for concordance. Consecutive CTC studies from a single screening program interpreted as positive for at least one detected colorectal lesion 6 mm or larger and sent for subsequent OC were analyzed according to per-polyp and per-patient results. Univariable and multivariable analysis of multiple input factors was performed. Of 1650 studies (median patient age, 59.7 years; 877 men and 773 women) with 2688 total CTC-detected lesions 6 mm or larger, the overall PPVs were 88.8% (2386/2688) by polyp and 90.8% (1499/1650) by patient. The by-polyp PPV was significantly higher for polypoid (91.2%; 1793/1965) versus flat or nonpolypoid (79.4%; 459/578) lesions ( < 0.0001). Overall per-patient PPVs were 72.3% (1193/1650) for any neoplasia 6 mm or larger and 38.8% (641/1650) for advanced neoplasia. PPVs for advanced neoplasia increased by CTC Reporting and Data System category: 5.8% (45/781) for C2, 67.1% (511/762) for C3, and 79.4% (85/107) for C4. PPVs for cancer also increased by CTC Reporting and Data System category: 0% (0/781) for C2, 2.2% (17/762) for C3, and 52.3% (56/107) for C4. On multivariable regression analysis, polyp morphologic type (flat vs polypoid) and diagnostic confidence were the strongest predictors of CTC-OC concordance. CTC PPV results are somewhat underestimated because 28.8% (87/302) of CTC-OC-discordant results were categorized as likely OC false-negatives at consensus review. Concordance between CTC and OC is high for relevant colorectal polyps and masses. Unlike stool-based tests that provide only a binary positive or negative result, CTC can specify the nature of the positive findings, resulting in much greater specificity and risk stratification for patient management decisions.
本研究的目的是评估在CT结肠成像（CTC）中影响检测大肠病变的阳性预测值（PPV）的因素，以光学结肠镜检查（OC）作为一致性的参考标准。对来自单一筛查项目的连续CTC研究进行分析，这些研究被解释为至少有一个检测到的6毫米或更大的大肠病变呈阳性，并随后进行OC检查，分析基于每个息肉和每个患者的结果。对多个输入因素进行单变量和多变量分析。在1650项研究（患者年龄中位数为59.7岁；男性877例，女性773例）中，共检测到2688个6毫米或更大的CTC病变，按息肉计算的总体PPV为88.8%（2386/2688），按患者计算为90.8%（1499/1650）。息肉样病变的按息肉PPV（91.2%；1793/1965）显著高于扁平或非息肉样病变（79.4%；459/578）（P<0.0001）。对于任何6毫米或更大的肿瘤，总体按患者PPV为72.3%（1193/1650），对于进展期肿瘤为38.8%（641/1650）。进展期肿瘤的PPV根据CTC报告和数据系统类别增加：C2为5.8%（45/781），C3为67.1%（511/762），C4为79.4%（85/107）。癌症的PPV也根据CTC报告和数据系统类别增加：C2为0%（0/781），C3为2.2%（17/762），C4为52.3%（56/107）。在多变量回归分析中，息肉形态类型（扁平与息肉样）和诊断置信度是CTC-OC一致性的最强预测因素。由于在共识审查中，28.8%（87/302）的CTC-OC不一致结果被归类为可能的OC假阴性，因此CTC的PPV结果有所低估。对于相关的大肠息肉和肿块，CTC与OC之间的一致性很高。与仅提供二元阳性或阴性结果的粪便检测不同，CTC可以明确阳性结果的性质，从而在患者管理决策中具有更高的特异性和风险分层。
