Endorectal Ultrasound Shear-Wave Elastography of Complex Rectal Adenoma and Early Rectal Cancer

Abstract

Purpose: To investigate the diagnostic performance of endorectal ultrasound (ERUS), shear-wave elastography (SWE), and magnetic resonance imaging (MRI) in patients with a complex rectal adenoma or an early rectal cancer, i.e., T1 or T2 adenocarcinoma in a clinical setting, and to evaluate the association between SWE and stromal fraction (SF) and apparent diffusion coefficient (ADC) and SF. Method: This prospective study included patients undergoing ERUS and SWE for a rectal tumor subsequently confirmed by histopathology to be an adenoma or a T1 or T2 adenocarcinoma. The accuracy of the imaging methods was assessed by comparing the T category as determined by ERUS and MRI with histopathology, which served as the gold standard. SF was assessed on surgical specimens. Results: A total of 86 patients were included. Of these, 62 patients had adenomas and 24 patients had carcinomas, of which 11 were T1 tumors and 13 were T2 tumors. ERUS and MRI yielded sensitivity, specificity, and accuracy of 0.79 and 0.73, 0.95 and 0.90, and 0.86 and 0.78, respectively, for discrimination between benign and malignant lesions. The area under the receiver operating characteristics curve for SWE was 0.88, and with a cut-off value of 40 kPa the sensitivity, specificity, and accuracy were 0.79, 0.89, and 0.86, respectively. There was a positive correlation between SF and SWE with a p-value of <0.001 and a negative correlation between SF and ADC with a p-value of 0.011. Conclusion: Both ERUS and MRI classified T categories with a high accuracy; however, ERUS classified more adenomas correctly than MRI. In this small population, SWE could differentiate an adenoma from early carcinoma. SF was correlated with both SWE and ADC, as increasing SF tended to yield higher SWE and lower ADC values.

Diffusion-Weighted MRI as a Quantitative Imaging Biomarker in Colon Tumors

“…The AUC in differentiating adenomas from pT1–pT2 was 0.80. This is in agreement with a study on rectal polyps [ 21 ]. Other rectal MRI studies have shown similar results [ 15 , 22 , 23 ], but the literature is scarce on colonic tumors.…”

Diagnostic advantages of transrectal ultrasound with gastrointestinal agent instillation for rectal adenoma and early-stage rectal cancer: comparison of conventional transrectal ultrasound techniques

“…First, there was a relatively small number of cases, only a few high rectal lesions were detected by the 360° circular-array probe up to 18 cm depth, and only a few patients facilitated the extension of the probe into the depth of 18 cm in practical application. Second, some studies have evaluated the diagnostic performance of endorectal ultrasound and shear-wave elastography in patients with complex rectal adenoma or early rectal cancer ( 25 ). Therefore, in future clinical research, we also plan to examine the use of shear-wave elastography and recruit more cases.…”

Value of biplane transrectal ultrasonography plus micro-flow imaging in preoperative T staging and rectal cancer diagnosis in combination with CEA/CA199 and MRI

“…Third, patients with factors that affect CEA, such as smoking, hepatopathy, nephropathy and diabetes, were not excluded in our study, which may have caused a false-positive CEA increase [ 33 ]. Fourth, we did not include shear wave transrectal ultrasound, which might have improved the results [ 47 ].…”