Comparison of the diagnostic accuracy of enhanced-CT and double contrast-enhanced ultrasound for preoperative T-staging of gastric cancer: a meta-analysis.

Background: Accurate preoperative staging of gastric cancer (GC) depends on effective diagnostic methods. Enhanced computed tomography (enhanced-CT) is a widely used and reliable preoperative assessment tool for GC, Double Contrast-Enhanced Ultrasound (DCEUS) can display the structure and layers of the gastric wall more accurately, and has high sensitivity (SE) and specificity (SP).

Objective: The present study aims to conduct a comprehensive meta-analysis comparing the preoperative T-staging accuracy of DCEUS and enhanced-CT.

Methods: A systematic literature search was conducted across PubMed, Embase, Web of Science, and Cochrane Library to identify eligible articles from inception to February 19, 2024. The study included both prospective and retrospective studies involving patients with GC who underwent DCEUS or enhanced-CT. This encompassed studies utilizing comparative diagnostic test accuracy (CDTA) with both DCEUS and enhanced-CT, as well as studies employing single diagnostic test accuracy (SDTA) with either DCEUS or enhanced-CT alone. Risk of bias was assessed using the Quality Assessment Of Diagnostic Accuracy Studies-C (QUADAS-C) and Assessment Of Diagnostic Accuracy Studies-2 (QUADAS-2) tool. The quality of evidence for each outcome was assessed using GRADE (Grading of Recommendations Assessment, Development and Evaluation).

Results: A total of 39 studies involving 6,374 patients were included in this meta-analysis. Among these, 3 studies (319 patients) directly compared dynamic contrast-enhanced ultrasound (DCEUS) and enhanced computed tomography (CT), while 31 studies (5,180 patients) evaluated enhanced CT alone, and 5 studies (875 patients) assessed DCEUS alone. For the direct comparison studies (CDTA), DCEUS demonstrated higher sensitivity (SE) and specificity (SP) for T1-T4 staging compared to enhanced CT, with moderate to low certainty of evidence. Specifically, DCEUS showed superior performance in detecting early-stage (T1) and advanced-stage (T4) tumors. Enhanced CT, while effective, had lower sensitivity across all stages, particularly for T1 tumors. In the single-modality studies (SDTA), DCEUS consistently showed higher sensitivity for T2-T4 staging compared to enhanced CT, with comparable specificity. However, the certainty of evidence for indirect comparisons was very low, highlighting the need for further high-quality comparative studies. Overall, DCEUS appears to be a promising modality for gastric cancer T staging, particularly for early-stage detection, but the limited number of direct comparative studies underscores the need for more robust evidence.

Conclusion: Current evidence indicates that DCEUS significantly outperforms enhanced-CT in terms of SE and diagnostic accuracy for preoperative T-staging of GC, while maintaining comparable SP. However, these findings require further validation through rigorous studies with larger sample sizes and improved methodological quality.