Endorectal ultrasound with elastography for differentiating benign and malignant rectal tumors: a systematic review and meta-analysis

Abstract

Background: Timely and precise diagnosis of rectal tumors is pivotal for improving patient outcomes. Despite advances in imaging technologies, differentiating benign adenomas from early-stage rectal cancer remains a significant challenge. The aim of this study was to assess the effectiveness of endorectal ultrasound (ERUS) elastography in differentiating rectal adenomas from cancer.

Methods: In accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, a comprehensive search of the PubMed, Embase, and Cochrane databases was performed to identify studies that used ERUS elastography to assess rectal adenomas and cancer. A random effects model was employed to pool the sensitivity, specificity, and diagnostic odds ratio (DOR) for ERUS elastography in the diagnosis of rectal tumors.

Results: Ten studies encompassing a total of 722 patients with rectal tumors were included in this meta-analysis. The pooled sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), and DOR of ERUS elastography for distinguishing benign from malignant rectal tumors were 93% (95% confidence intervals (CI), 88%-96%), 86% (95% CI, 78%-92%), 6.71 (95% CI, 4.14-10.86), 0.08 (95% CI, 0.05-0.14), and 84 (95% CI, 38-186), respectively. The summary receiver operating characteristic (SROC) curve demonstrated an area under the curve (AUC) of 0.95 (95% CI, 0.93-0.97).

Conclusion: ERUS elastography greatly enhances diagnostic precision by distinguishing rectal adenomas from cancer, providing an effective approach to differentiate benign from malignant rectal lesions.

Keywords: Rectal neoplasms; diagnosis; elastography; ultrasound.

Figure 1

Diagram illustrating the literature search process.

Figure 2

The quality evaluation of the included studies was performed using QUADAS-2, which summarizes “risk of bias” and “applicability concerns” by assessing each domain for every study included. A. Evaluation of risk of bias in the included studies. B. Assessment of applicability concerns in the included studies.

Figure 3

Forest plot of included studies evaluating the sensitivity and specificity of ERUS with elastography in distinguishing benign from malignant rectal tumors. A. Sensitivity evaluation of ERUS with elastography in distinguishing rectal tumors. B. Specificity evaluation of ERUS with elastography in distinguishing rectal tumors. CI, confidence intervals.

Figure 4

Forest plot of included studies assessing the NLR and PLR of ERUS with elastography in differentiating benign and malignant rectal tumors. A. PLR evaluation of ERUS with elastography in differentiating rectal tumors. B. NLR evaluation of ERUS with elastography in differentiating rectal tumors. CI, confidence intervals.

Figure 5

Forest plot of included studies assessing the DOR of ERUS with elastography in differentiating benign and malignant rectal tumors. CI, confidence intervals.

Figure 6

SROC curve of ERUS with elastography in differentiating benign and malignant rectal tumors. SROC curves of ERUS with elastography for assessing the differentiation between benign and malignant rectal tumors illustrate its diagnostic performance. Each circle represents a study. The SROC curve is symmetric, and the AUC is 0.95, indicating excellent diagnostic accuracy for this evaluation. SROC, summary receiver operating characteristic; AUC, area under the curve.

Figure 7

Deeks’ test results for the assessment of publication bias in ERUS with elastography studies. Each circle corresponds to a single study, and the line represents the regression line. Because the p value is greater than 0.05, no publication bias is present. ESS, effective sample size.