From the Department of Medical Ultrasonics, Institute of Diagnostic and Interventional Ultrasound, the First Affiliated Hospital of Sun Yat-Sen University, 58 Zhongshan Road 2, Guangzhou 510080, People's Republic of China (L.D.C., W.W., J.Y.L., M.D.L., X.Y.X.); Departments of Gastrointestinal Surgery (J.B.X., J.H.C., X.H.Z., H.W., J.N.Y.) and Hepatobiliary Surgery (M.D.L.), the First Affiliated Hospital of Sun Yat-Sen University, Guangzhou, China; and Department of Epidemiology, Guangdong Cardiovascular Institute, Guangdong General Hospital, Guangdong Academic of Medical Science, Guangzhou, China (Z.Q.N.).
Radiology. 2017 Oct;285(1):279-292. doi: 10.1148/radiol.2017162128. Epub 2017 Jun 21.
Purpose To compare the value of endorectal ultrasonography (US) with shear-wave elastography (SWE) in staging rectal tumors before surgery. Materials and Methods This prospective study was approved by the institutional review board and written informed consent was obtained. In a pilot cohort from April 2015 to January 2016, 70 patients with rectal adenocarcinomas and/or adenomas confirmed with histopathologic examination underwent both endorectal US and SWE. Tumor stiffness and three regions of reference backgrounds, as well as tumor stiffness ratios (SRs) versus these backgrounds, were analyzed. The optimal staging feature was selected by using receiver operating characteristic analysis, and the concordance rate with pathologic stage was analyzed and compared with endorectal US. The results were validated in an independent cohort of 30 patients from February 2016 to July 2016. Results In the pilot study, from rectal adenoma to stage T3 cancers, the tumor stiffness, stiffness of peritumoral fat, tumor SR versus distant perirectal fat, and tumor SR versus normal rectal wall were significantly increased (all P < .05, correlation coefficients between SWE features and pathologic T stages were 0.589-0.853). Receiver operating characteristic analysis of tumor staging demonstrated that tumor stiffness was the optimal feature with the highest area under the receiver operating characteristic curve (AUC = 0.991-1.000). The cutoff values of stage T1, T2, and T3 cancers were 26.9 kPa, 70.3 kPa, and 112.0 kPa, respectively. For SWE, the diagnostic concordance rate with pathologic stage (95.7%, weighted κ = 0.962) was higher than that of endorectal US (75.7%, weighted κ = 0.756). In the validation cohort, similar findings were revealed for diagnostic concordance rate (93.3% vs 76.7%; weighted κ = 0.927 vs 0.651) and diagnostic performance of tumor staging (AUC = 0.950-1.000 vs 0.700-0.833). Conclusion By using the feature of tumor stiffness at SWE, the accuracy of preoperative staging for rectal tumors was improved compared with endorectal US in the pilot study, but was not significantly different in the validation cohort, potentially due to small sample size. RSNA, 2017 Online supplemental material is available for this article.
比较直肠内超声（endorectal ultrasonography，EUS）与剪切波弹性成像（shear-wave elastography，SWE）在术前评估直肠肿瘤分期方面的价值。
本前瞻性研究经机构审查委员会批准，并获得书面知情同意。在 2015 年 4 月至 2016 年 1 月的初步队列研究中，70 例经组织病理学检查证实为直肠腺癌和/或腺瘤的患者均接受了直肠内 EUS 和 SWE 检查。分析了肿瘤硬度以及 3 个参考背景区域，以及肿瘤硬度比值（stiffness ratio，SR）与这些背景之间的关系。采用受试者工作特征（receiver operating characteristic，ROC）分析选择最佳分期特征，并与直肠内 EUS 进行分析和比较。在 2016 年 2 月至 7 月的独立队列中验证了这些结果。
在初步研究中，从直肠腺瘤到 T3 期癌症，肿瘤硬度、肿瘤周围脂肪硬度、肿瘤 SR 与远处直肠周围脂肪、肿瘤 SR 与正常直肠壁之间的差异均有统计学意义（均 P＜.05，SWE 特征与病理 T 分期之间的相关系数为 0.589-0.853）。肿瘤分期的 ROC 分析显示，肿瘤硬度是最佳特征，ROC 曲线下面积（area under the receiver operating characteristic curve，AUC）最高（0.991-1.000）。T1、T2 和 T3 期癌症的截断值分别为 26.9 kPa、70.3 kPa 和 112.0 kPa。对于 SWE，与病理分期的诊断一致性（95.7%，加权 κ=0.962）高于直肠内 EUS（75.7%，加权 κ=0.756）。在验证队列中，诊断一致性（93.3% vs 76.7%；加权 κ=0.927 vs 0.651）和肿瘤分期的诊断性能（AUC=0.950-1.000 vs 0.700-0.833）也得到了类似的发现。
在初步研究中，与直肠内 EUS 相比，SWE 采用肿瘤硬度特征可提高直肠肿瘤术前分期的准确性，但在验证队列中差异无统计学意义，可能与样本量小有关。RSNA，2017 年。在线补充材料可在本文中查看。
