Can Ultrasound Elastography Discriminate between Rectal Adenoma and Cancer? A Systematic Review

Abstract

Background: Rectal cancer is a common malignancy. Since the introduction of bowel-screening programs, the number of patients with advanced adenomas and early rectal cancer has increased. Despite improved diagnostics, the discrimination between rectal adenomas and early rectal cancer (i.e., pT1–T2) remains challenging. The purpose of this systematic review was to evaluate the diagnostic performance of endorectal ultrasound (ERUS) elastography in discriminating rectal adenomas from cancer. Method: Using PRISMA guidelines, a systematic search was performed on PubMed, Embase, and MEDLINE databases. Studies evaluating the primary staging of rectal adenomas and cancer using ERUS elastography were included. Results: Six studies were identified; three evaluated the discrimination between adenomas and cancer; two evaluated adenomas and early rectal cancer (i.e., pT1–T2); one evaluated performance on different T categories. All studies reported increased diagnostic accuracy of ERUS elastography compared to ERUS. Sensitivity, specificity and accuracy ranged 0.93–1.00, 0.83–1.00 and 0.91–1.00, respectively, when discriminating adenomas from cancer. In the differentiation between adenomas and early rectal cancer, the sensitivity, specificity and accuracy were 0.82–1.00, 0.86–1.00 and 0.84–1.00, respectively. Conclusion: Elastography increases the accuracy of ERUS and may provide valuable information on malignant transformation of rectal lesions.

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

“…The European Federation of Societies for Ultrasound in Medicine and Biology (EFSUMB) and European Society of Medical Oncology (ESMO) recommend endorectal ultrasound (ERUS) when evaluating early rectal cancer [ 1 , 6 ]. According to a recent review, ultrasound elastography provides information on tissue stiffness and increases the ability of ERUS to distinguish between a rectal adenoma and cancer [ 7 ]. Two elastography techniques are used in clinical practice, strain elastography (SE) and shear-wave elastography (SWE).…”

Fundamentals of Bowel Cancer for Biomedical Engineers

“…Fundamentals of biomechanics reviewed above can be applied to study the physicochemical properties of biological materials, such as healthy and malignant tissues. To analyse the mechanical properties of soft biological samples, various techniques, such as atomic force microscopy, 24 , 115 , 126 shear rheometer, 24 tactile sensor 57 , 127 and ultrasound elastography, 73 , 120 , 122 were developed, which are illustrated in Fig. 5 .…”

“…122 , 128 Particularly, it is useful for detecting the presence and severity of glandular disorders, 85 myocardial stiffness, 106 musculoskeletal pathologies, 108 liver disease, 47 inflammatory bowel disease 123 and bowel cancer. 19 , 29 , 45 , 73 The measurement is to examine how quickly these vibrations move through the organ, and then this information will be used to create a visual map revealing the differences in the elastic properties of soft tissues for further diagnosis. On the other hand, conventional ultrasound diagnostic images can only visualise the differences in soft tissue acoustic properties through the echogenicity of ultrasound waves passing through the soft tissue, 62 , 68 , 75 whereas ultrasound elastography (USE) images (Fig.…”

Decellularized Colorectal Cancer Matrices as Bioactive Scaffolds for Studying Tumor-Stroma Interactions

“…Solid tumors are constantly affected by mechanical stimuli, such as compression, matrix stiffness and fluid mechanics [ 83 , 84 ]. Tissue elasticity can be measured by shear wave elastography to discriminate between malignant and benign tissues, rheology and atomic force microscopy (AFM), which provide images of mechanical properties of biological samples with a high spatial resolution and result in elastographic data [ 85 , 86 ]. In the case of CRC, this is particularly interesting because the gastrointestinal tract is naturally submitted to more pronounced endogenous mechanical stress due to intestinal transit, leading to an extremely complex mechanical microenvironment [ 87 ].…”