Research ArticlePreoperative gadoxetic acid–enhanced MRI for predicting microvascular invasion in patients with single hepatocellular carcinoma
Graphical abstract
Introduction
Vascular invasion, either macrovascular or microvascular invasion (MVI), is a well-known major prognostic factor of hepatocellular carcinoma (HCC), after surgical resection or liver transplantation.[1], [2], [3], [4] In particular, MVI of HCC is a major risk factor for early recurrence during the first 2 years after curative treatment.[5], [6] Although macrovascular invasion can be frequently detected prior to surgery by complementary imaging modalities, including computed tomography (CT) and magnetic resonance (MR) imaging, MVI can rarely be determined preoperatively because it is a histopathological diagnosis. It is therefore of great importance to identify preoperative imaging biomarkers for predicting MVI.
Several studies have reported that certain imaging findings including tumor size,[7], [8] arterial rim enhancement9 or peritumoral enhancement,[7], [8], [9] tumor margin,[8], [10] tumor hypointensity11 or peritumoral hypointensity on hepatobiliary phase (HBP),12 radiological capsule10 on gadoxetic acid–enhanced MR imaging, and higher tumor-to-liver signal intensity (SI) ratio and lower apparent diffusion coefficient (ADC) value on diffusion-weighted (DW) imaging with ADC map,[13], [14], [15] are useful for predicting MVI of HCC. Although these studies have reported imaging features for predicting MVI, there is still debate over which best reflects the MVI of HCC, which results in early recurrence after hepatic resection. Kim et al.16 and Ahn et al.7 suggested that arterial peritumoral enhancement was associated with a high probability of MVI. Ariizumi et al.10 revealed that only non-smooth margin was an independent predictor of MVI, whereas Kim et al.12 reported that only peritumoral hypointensity on HBP was significant in predicting MVI. Also, in previous studies using resected tumor, HCC larger than 5 cm in maximum diameter showed a greater chance of spreading through MVI.[17], [18], [19] An et al.9 demonstrated that MR imaging findings such as arterial rim, peritumoral enhancement and tumor size were independently associated with early recurrence. However, to the best of our knowledge, there have been few attempts to evaluate the diagnostic performance of the most significant MR imaging features and their combinations for predicting MVI of HCC and the risk of early recurrence. In addition, there are limited studies that have investigated MR imaging findings for predicting MVI for HCC with diameter of 5 cm or smaller.
The purpose of this study was to identify preoperative MR imaging biomarkers for predicting MVI, to determine their diagnostic performance and to evaluate whether they are associated with early recurrence after curative resection of single HCC ≤5 cm.
Section snippets
Materials and methods
The institutional review board approved this retrospective study and waived the requirement for informed consent.
Results
Among 197 HCCs, 63 had MVI, while 134 had no MVI. Comparisons of clinicopathologic characteristics between HCCs with or without MVI are summarized in Table 1. Baseline variables, including age, sex, background liver, and origin of liver disease, were similar in both groups (p >0.05). For serum levels of tumor markers, HCCs with MVI showed more abnormal and higher serum AFP and PIVKA-II levels than those without MVI (p = 0.004 and p = 0.004, respectively; normal reference values of AFP and PIVKA-II
Discussion
Our results demonstrated that arterial peritumoral enhancement, non-smooth tumor margin, and peritumoral hypointensity on gadoxetic acid–enhanced HBP images were independent and significant predictors of MVI of HCCs, with good or excellent interobserver agreement. Combining two or three MR imaging findings for predicting MVI resulted in specificity greater than 92%. In addition, early recurrence rate was significantly higher in patients with two or three MR imaging findings compared to those
Conflict of interest
The authors who have taken part in this study declared that they do not have anything to disclose regarding funding or conflict of interest with respect to this manuscript.
Authors’ contributions
Dr Seong Hyun Kim had full access to all of the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis.
Dr Sunyoung Lee contributed to the study concept and design, acquisition of data, statistical analysis, analysis and interpretation of data, and drafting of the manuscript.
Dr Seong Hyun Kim contributed to the study concept and design, analysis and interpretation of data, drafting of the manuscript, and critical revision of the manuscript
References (37)
- et al.
Recurrence after liver resection for hepatocellular carcinoma: risk factors, treatment, and outcomes
Surgery
(2007) - et al.
Risk factors contributing to early and late phase intrahepatic recurrence of hepatocellular carcinoma after hepatectomy
J Hepatol
(2003) - et al.
Hyperintense HCC on hepatobiliary phase images of gadoxetic acid-enhanced MRI: correlation with clinical and pathological features
Eur J Radiol
(2012) - et al.
Diffusion-weighted magnetic resonance imaging predicts malignant potential in small hepatocellular carcinoma
Dig Liver Dis
(2016) - et al.
Predictive value of gross classification of hepatocellular carcinoma on recurrence and survival after hepatectomy
J Hepatol
(2000) - et al.
The role of macroscopic classification in nodular-type hepatocellular carcinoma
Am J Surg
(2001) - et al.
Alpha-fetoprotein and tumour size are associated with microvascular invasion in explanted livers of patients undergoing transplantation with hepatocellular carcinoma
HPB
(2010) - et al.
MRI findings of rapidly progressive hepatocellular carcinoma
Magn Reson Imaging
(2010) - et al.
Prognostic histologic indicators of curatively resected hepatocellular carcinomas: a multi-institutional analysis of 425 patients with definition of a histologic prognostic index
Am J Surg Pathol
(2002) - et al.
Liver transplantation for hepatocellular carcinoma validation of present selection criteria in predicting outcome
Liver Transpl
(2004)