The Liver Imaging Reporting and Data System tumor-in-vein category: a systematic review and meta-analysis

• Published in: European radiology Vol. 31; no. 4; pp. 2497 - 2506
• Main Authors: Kim, Dong Hwan, Choi, Sang Hyun, Park, Seong Ho, Kim, Kyung Won, Byun, Jae Ho, Kim, So Yeon, Lee, Seung Soo, Choi, Joon-Il
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.04.2021; Springer Nature B.V
• Subjects: Carcinoma, Hepatocellular - diagnostic imaging; Case-Control Studies; Cohort Studies; Computed tomography; Confidence intervals; Diagnostic Radiology; Etiology; Hepatitis; Hepatitis C; Hepatobiliary-Pancreas; Hepatocellular carcinoma; Heterogeneity; Humans; Imaging; Internal Medicine; Interventional Radiology; Liver; Liver cancer; Liver diseases; Liver Neoplasms - diagnostic imaging; Magnetic Resonance Imaging; Mathematical analysis; Medical diagnosis; Medical imaging; Medicine; Medicine & Public Health; Meta-analysis; Neuroradiology; Pathology; Radiology; Regression analysis; Retrospective Studies; Statistical analysis; Subgroups; Tumors; Ultrasound; Hepatocellular carcinoma; Systematic review; Diagnosis; Liver; Meta-analysis
• ISSN: 0938-7994; 1432-1084
• DOI: 10.1007/s00330-020-07282-x

Objectives We aimed to systematically determine the etiology of the Liver Imaging Reporting and Data System (LI-RADS) tumor-in-vein category (LR-TIV) on contrast-enhanced CT or MRI and to determine the sources of heterogeneity between reported results. Methods Original studies reporting the etiology of LR-TIV were identified in MEDLINE and EMBASE up until July 7, 2020. The meta-analytic pooled percentages of HCC and non-HCC in LR-TIV were calculated. Subgroup analyses were performed according to the type of reference standard and the most common underlying liver disease. Meta-regression analysis was performed to explore study heterogeneity. Results Sixteen studies reported the etiology of a total of 150 LR-TIV, of which 98 (65%) were HCC and 52 (35%) were non-HCC. The meta-analytic pooled percentages of HCC and non-HCC in LR-TIV were 70.9% (95% confidence interval [CI], 55.7–82.5%; I 2 = 59%) and 29.2% (95% CI, 17.5–44.4%; I 2 = 59%), respectively. The meta-analytic pooled percentage of HCC was lower in studies using only pathology as a reference standard (67.1%; 95% CI, 49.3–81.1%), but higher in studies in which hepatitis C was the most common underlying liver disease (81.9%; 95% CI, 11.3–99.4%) than that in the total 16 studies. Study type (cohort study versus case-control study) was significantly associated with study heterogeneity ( p = 0.04). Conclusion The most common etiology of LR-TIV was HCC. It might be important to understand the percentage of HCC and non-HCC in LR-TIV in consideration of the type of reference standard, geographic differences, and study design. Key Points • The most common etiology of Liver Imaging Reporting and Data System (LI-RADS) tumor-in-vein category (LR-TIV) was hepatocellular carcinoma (HCC). • The percentage of HCC in LR-TIV was relatively low in studies using only pathology as a reference standard, but high in studies in which hepatitis C was the most common underlying liver disease. • Study type was a factor significantly influencing study heterogeneity.