Diagnostic performance of ultrasound elastography in differentiating hepatocellular carcinoma and intrahepatic cholangiocarcinoma: a systematic review and meta-analysis

PurposeTo evaluate the diagnostic value of ultrasound elastography (USE) for characterizing hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (ICC).MethodsThe protocol was pre-registered a priori at (https://osf.io/namvk/). Using PubMed, Web of Science, Embase, and Cochrane Library, we found studies up to April 20, 2024 by searching HCC, ICC, and USE as keywords. Parameters of USE were directly compared between HCC and ICC patients using random-effects bivariate model on STATA 17.0, MedCalc 20.0, and Psychometrica. Trim & fill method and sensitivity analysis were also performed.ResultsEighteen studies were included with 1057 patients, consisting of 863 HCC lesions, 188 ICC lesions, and 6 mixed lesions. The pooled Emean values of HCC and ICC were 28.3 (CI = 19.8 to 36.8) and 44.0 (CI = 20.9 to 67.2). HCC tumors were 34.3% softer than ICC while peritumoral tissue in HCC lesions was 75% stiffer than ICC lesions based on Emean. The strain value index (tumoral-to-peritumoral ratio) in HCC patients was 49.4% less than that of ICC patients. USE demonstrated a pool sensitivity of 87% (CI = 73-95%), specificity of 82% (CI = 65-92%), positive likelihood ratio of 4.8 (CI = 2.2 to 10.3), negative likelihood ratio of 0.16 (CI = 0.07 to 0.37), and diagnostic odds ratio of 31 (CI = 7 to 127) in differentiation of ICC from HCC.ConclusionBy evaluating tumoral and pre-tumoral stiffness, along with strain value index, USE may provide a valuable quantitative diagnostic tool for accurately differentiating HCC and ICC.