The Value of Magnetic Resonance Imaging and Endorectal Ultrasound for the Accurate Preoperative T-staging of Rectal Cancer

Abstract

Magnetic resonance imaging (MRI) and endorectal ultrasound (ERUS) are essential imaging modalities to assess the depth of tumour invasion (T-staging) in rectal cancer preoperative staging. Accurate T-staging is critical for rectal cancer prognosis and has substantial importance in the determination of appropriate treatment strategies for rectal tumours. There seems to be a knowledge gap in the published literature regarding the most appropriate imaging modality for the preoperative staging of rectal cancer. The purpose of this study was to determine the most appropriate imaging technique for the preoperative T-staging of rectal cancer by comparing the MRI and ERUS staging. In this study, we performed a literature review of studies published in the last 10 years and compared the accuracy, sensitivity, and specificity of ERUS and MRI for the preoperative T-staging of rectal cancer with the aim of identifying the most appropriate imaging modality. The studies reviewed were selected by a rigorous literature search of academic databases. Three electronic databases (PubMed, CINAHL, and Scopus) were searched, and articles were identified. Further rescreening of the articles for those that met the inclusion criteria and searching of the citations of the articles produced eleven journal articles used in this research. Endorectal ultrasound produces accurate results for the T-staging of early rectal cancer, particularly T1 and T2, and has the ability to show the layers of the bowels more clearly in early-stage rectal cancer. However, MRI shows more accurate results for the staging of locally advanced tumours such as advanced T3 and T4 and is particularly important when estimating tumour invasion into the mesorectum, which is very important for the prognostication and survival of patients with rectal cancer. MRI has low accuracy for differentiating early T3 tumours from T1 or T2 with desmoplastic reactions, and therefore, is more likely to overstage these tumours.

The Value of Transanal Normal Saline Infusion–Assisted Multipath Ultrasonography in the Diagnosis of T1/T2 Rectal Cancer

“…In addition, there may be inflammatory reactions at the edge of the tumor, and the ultrasound image often is not clear enough to distinguish a tumor from surrounding tissue with inflammation, so the boundary of the lesion displayed on the ultrasound image may be beyond the actual boundary of the tumor or the depth of invasion. At this time, the ultrasonography results are overestimated compared with the pathological results 14 . Limitations of this study are as follows: data were derived from single-center studies, and with high dependence on checking operators, and consistency between operators was not studied.…”

“…At this time, the ultrasonography results are overestimated compared with the pathological results. 14 Limitations of this study are as follows: data were derived from single-center studies, and with high dependence on checking operators, and consistency between operators was not studied. This study focuses on methodological discussion, and preliminarily judges the application value of TNSI-MU in T1/T2 RC, and the number of cases of T1/T2 RC is small, and the sample size will be expanded in the future.…”

Preoperative prediction of lymphovascular invasion and T-staging of rectal cancer via a dual-energy computed tomography iodine map: a feasibility study

“…1,7 Transrectal ultrasonography (TRUS) and magnetic resonance imaging (MRI) have been widely used for preoperative T-staging of RC, and the diagnostic accuracies of TRUS for preoperative T-staging of patients with RC have been reported in the literature to range from 71% to 95%. 8 However, the diagnostic accuracy of TRUS is highly dependent on the experience and skill of the operator. 9 Moreover, the field of view of TRUS is limit-ed, and high-grade and stenotic tumors are often difficult to reach with the probe.…”