Diagnostic Accuracy of Double Contrast-Enhanced Ultrasonography in Clarifying Tumor Depth (T Stage) of Gastric Cancer: Meta-analysis.

This study aimed to quantitatively analyze published data regarding the ability of double contrast-enhanced ultrasonography (DCEUS) to clarify tumor depth (T stage) in primary gastric carcinoma patients. We obtained six studies, including 926 gastric cancer (GC) patients who were diagnosed by DCEUS from the Cochrane Library "Cochrane Central Register of Controlled Trials (CENTRAL)," OVID MEDLINE, EMBASE, PUBMED and EBSCOhost, to 2019. Sensitivity (SEN), specificity (SPE), positive likelihood ratio (PLR), negative likelihood ratio (NLR), forest plot analysis and summary receiver operating characteristic (SROC) curve analysis were used to evaluate the diagnostic accuracy of DCEUS. In our study, all the patients were examined by DCEUS. The quality of all included studies was good. The meta-analysis of six studies (n = 926) revealed that the summary sensitivity and specificity of DCEUS in discriminating T1-T2 versus T3-T4 gastric carcinomas were 0.94 and 0.91, respectively. The pooled sensitivity and specificity of DCEUS were 0.67 and 0.98 for T1 stage, 0.81 and 0.95 for T2 stage, 0.89 and 0.86 for T3 stage and 0.87 and 0.96 for T4 stage, respectively. The SROC curve revealed that the areas under the curve (AUC) of T1-T2 were 0.97 for each stage and 0.82 (T1), 0.84 (T2), 0.91 (T3) and 0.97 (T4). These results indicate that the accuracy of DCEUS in discriminating T1-T2 is higher than that in discriminating T3-T4, and the diagnostic value of DCEUS in discriminating the T3 stage requires further consideration. Finally, our analysis suggested that the diagnostic accuracy of DCEUS is available to guide surgeons in the pre-operative diagnosis of GC patients for more precise treatment.