Contrast-enhanced ultrasound for the characterization of portal vein thrombosis vs tumor-in-vein in HCC patients: a systematic review and meta-analysis.

Abstract

Portal vein thrombosis (PVT) is a common complication of liver cirrhosis. However, differentiation of thrombosis and tumor-in-vein (TIV) may be challenging. Contrast-enhanced ultrasound (CEUS) is an excellent method for detection of vascularization and could help in the distinction. We performed a systematic review and meta-analysis for evaluating the diagnostic value of CEUS in differentiating between PVT and TIV in hepatocellular carcinoma (HCC) patients. PubMed, Embase, Cochrane Library, and Web of Science were searched up to the 5th of May 2019. The study quality was assessed by QUADAS-2 tool. Pooled sensitivity and specificity were calculated by the bivariate random effect model and hierarchical summary receiver-operating characteristic (SROC) curve was plotted. Seven studies including 425 participants were analyzed after screening 986 articles searched from databases. The pooled sensitivity and specificity of CEUS in diagnosing TIV were 0.94 (95%CI, 0.89-0.97) and 0.99 (95%CI, 0.80-1.00), respectively. The area under the curve (AUC) of SROC curve was 0.97 (95%CI, 0.95-0.98). The pooled sensitivity and AUC were consistent across all the subgroups of different subject numbers, country, study design, CEUS contrast agents, and diagnostic criteria. CEUS is highly efficient in differentiating TIV from PVT and is an alternative or a substitute for CT and/or MRI. PROSPERO registration number: CRD42019138847 KEY POINTS: • Characterization of portal vein thrombosis (PVT) vs tumor-in-vein (TIV) is critical for HCC staging. • CEUS has an excellent safety profile, provides a real-time analysis without any loss in accuracy compared with CT and MRI. • This meta-analysis demonstrates that contrast-enhanced ultrasound (CEUS) is a suitable method for the detection of PVT and distinction with TIV.