Elsevier

Gastrointestinal Endoscopy

Volume 90, Issue 2, August 2019, Pages 196-203.e1
Gastrointestinal Endoscopy

Systematic review and meta-analysis
EUS versus magnetic resonance imaging in staging rectal adenocarcinoma: a diagnostic test accuracy meta-analysis

Presented Digestive Disease Week, June 2-5, 2018, Washington, DC (Chan BP, Patel R, Yaghoobi M. EUS versus MRI in staging rectal adenocarcinoma: a diagnostic test accuracy meta-analysis. Gastroenterology 2018;154:S661-2).
https://doi.org/10.1016/j.gie.2019.04.217Get rights and content

Background and Aims

EUS and magnetic resonance imaging (MRI) are both used for locoregional staging of rectal cancer, which determines treatment options. There is a lack of consensus on the best modality for locoregional staging, with studies supporting both EUS and MRI. In this study, we performed the first diagnostic test accuracy meta-analysis to compare the diagnostic accuracy, sensitivity, and specificity of EUS and MRI in the staging of rectal cancer.

Methods

A comprehensive electronic literature search up to June 2018 was performed to identify prospective cohort studies directly comparing the accuracy of EUS with MRI in staging nonmetastatic rectal cancer with surgical pathology as the reference standard. Quality of the included studies was measured by using the Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) tool. A bivariate hierarchical model was used to perform the meta-analysis of diagnostic test accuracy according to the Cochrane approved methodology. Summary receiver operating characteristics were developed, and the area under the curve was calculated for overall and individual T and N staging, for EUS, MRI, and head-to-head comparison.

Results

Six of 2475 studies including 234 patients were eligible. Pooled sensitivity and specificity in T staging were .79 (95% confidence interval [CI], .72-.85) and .89 (95% CI, .84-.93) for EUS and .79 (95% CI, .72-.85) and .85 (95% CI, .79-.90) for MRI, respectively. Pooled sensitivity and specificity in N staging were .81 (95% CI, .71-.89) and .88 (95% CI, .80-.94) for EUS and .83 (95% CI, .73-.90), and .90 (95% CI, .82-.95) for MRI, respectively. In area under the curve head-to-head analysis, EUS was superior to MRI in overall T staging (P < .05). EUS outperformed MRI in overall T, overall N, T1, and T3 staging (P < .01), after excluding studies using an endorectal coil for MRI. MRI was superior to EUS in T2 staging (P = .01) in both analyses.

Conclusions

EUS and MRI both provide reasonable diagnostic accuracy in the staging of nonmetastatic rectal cancer. EUS was superior to MRI in overall T staging and overall T and N staging after adjusting for MRI technology. Practitioners should be aware of advantages and disadvantages of both modalities and choose appropriate methods while considering diagnostic accuracy of each test and institutional practices and limitations.

Section snippets

Registration

The study protocol was registered (CRD42017069308) with the International Prospective Register of Systematic Reviews.

Study selection

Studies directly comparing the accuracy of EUS and MRI in staging rectal cancer with surgical pathology as the reference standard were included. No restrictions were placed on US frequency or type of EUS used or on the field strength or type of coil used for MRI.

Studies using nonendoscopic US, such as rigid endorectal sonography, were excluded. Studies with insufficient data,

Literature Search

Six of 2475 studies were included in the diagnostic test accuracy meta-analysis. Figure 1 depicts the Preferred Reporting Items for Systematic Reviews and Meta-Analyses flowchart for the detail of study selection and Table 1 the characteristics of included studies. Quality of included studies and risk of bias using the QUADAS-2 tool are represented in Figure 2.

Comparison of EUS and MRI

In overall T staging, EUS was significantly superior with an AUC of .87 (95% CI, .83-.90) as compared with .82 (95% CI, .78-.86) for MRI

Discussion

To our knowledge, this is the first diagnostic test accuracy meta-analysis comparing EUS and MRI in staging rectal cancer as compared with surgical pathology as the reference standard, in a head-to-head comparison, using appropriate methodology by the Cochrane Collaboration.7 Although both EUS and MRI showed reasonable diagnostic accuracy, EUS significantly outperformed MRI in overall T staging of rectal cancer in head-to-head analysis. After adjusting for technology and removing studies that

References (22)

  • D.G. Altman et al.

    Interaction revisited: the difference between two estimates

    BMJ

    (2003)
  • Cited by (32)

    • Transanal approaches to rectal neoplasia

      2022, Seminars in Colon and Rectal Surgery
      Citation Excerpt :

      Despite these reported optimistic staging accuracies obtained from high-resolution rectal protocoled MRI, reliably establishing whether a presumed early-rectal tumor is confined to the upper, mid, or lower portion of the submucosa, or even the muscularis propria and contains nodal disease remains an ongoing diagnostic challenge. While MRI is more often considered the better imaging modality for rectal cancer staging, ERUS has been shown to be the more accurate modality for early stage tumors, specifically T1.11,17 However, most ERUS studies still report an overall limited accuracy, with a modest 57% diagnostic accuracy for T1 tumors and 50% accuracy for T2 tumors, with a multi-institutional series reporting accuracy ranging between 63 and 69%.18,19

    • New scoring system to distinguish deep invasive submucosal and muscularis propria colorectal cancer during colonoscopy: a development and global multicenter external validation study (e-T2 Score)

      2022, Gastrointestinal Endoscopy
      Citation Excerpt :

      In a study of preoperative T-stage diagnostic ability using CT colonography for 256 CRCs, the diagnostic accuracy of Tis/T1 versus T2 versus T3/T4 based on intestinal wall deformity was 77.6%.32 A meta-analysis including 234 patients with rectal cancer reported that the pooled sensitivity and specificity of MRI for T-staging was 79% (95% CI, 72-85) and 85% (95% CI, 79-90), and the AUC of MRI was superior to that of EUS for T2 staging (.92 vs .82, P < .01).33 In a meta-analysis including 208 cancers of the colon proximal to the rectum (T1, 39; T2, 35), the pooled sensitivity and specificity of T1 were good at 90% (95% CI, 66-98) and 98% (95% CI, 94-99), respectively.

    • Multidisciplinary management of early rectal cancer – The role of surgical local excision in current and future clinical practice

      2022, Surgical Oncology
      Citation Excerpt :

      If performed by an experienced physician, ERUS may help to differentiate T1 from T2 tumours [43]. Moreover, Chan and co-workers [44] reported that ERUS outperformed MRI in more advanced T3 tumours, presumably due to a higher sensitivity of smaller lesions and ability to differentiate thin layers such as the serosa. However, it is difficult to determine the distance to the mesorectal fascia in posterior tumours.

    • Interventional gastroenterology in oncology

      2023, CA Cancer Journal for Clinicians
    View all citing articles on Scopus

    DISCLOSURE: Dr Yaghoobi: Speaker for Abbvie and Pendopharm, research grant from Medtronic, and research support for this study from an Internal Career Award, Department of Medicine, McMaster University. All other authors disclosed no financial relationships relevant to this publication.

    See CME section; p. 301.

    View full text