Published online Jun 7, 2019. doi: 10.3748/wjg.v25.i21.2636
Peer-review started: February 22, 2019
First decision: March 27, 2019
Revised: April 30, 2019
Accepted: May 8, 2019
Article in press: May 8, 2019
Published online: June 7, 2019
Processing time: 104 Days and 9.5 Hours
Although important for determining long-term outcome, pathologic stage of hepatocellular carcinoma (HCC) is difficult to predict before surgery. Current state-of-the-art magnetic resonance imaging (MRI) using gadoxetic acid provides many imaging features that could potentially be used to classify single HCC as pT1 or pT2.
To determine which gadoxetic acid-enhanced MRI (EOB-MRI) findings predict pathologic stage T2 in patients with solitary HCC (cT1).
Pre-operative EOB-MRI findings were reviewed in a retrospective cohort of patients with solitary HCC. The following imaging features were examined: Hyperintensity in unenhanced T2-weighted images, hypointensity in unenhanced T1-weighted images, arterial enhancement, corona enhancement, washout appearance, capsular appearance, hypointensity in the tumor tissue during the hepatobiliary (HB) phase, peritumoral hypointensity in the HB phase, hypointense rim in the HB phase, intratumoral fat, hyperintensity on diffusion-weighted imaging, hypointensity on apparent diffusion coefficient map, mosaic appearance, nodule-in-nodule appearance, and the margin (smooth or irregular). Surgical pathology was used as the reference method for tumor staging. Univariate and multivariate analyses were performed to identify predictors of microvascular invasion or satellite nodules.
There were 39 (34.2%; 39 of 114) and 75 (65.8%; 75 of 114) pathological stage T2 and T1 HCCs, respectively. Large tumor size (≥ 2.3 cm) and two MRI findings, i.e., corona enhancement [odds ratio = 2.67; 95% confidence interval: 1.101-6.480] and peritumoral hypointensity in HB phase images (odds ratio = 2.203; 95% confidence interval: 0.961-5.049) were associated with high risk of pT2 HCC. The positive likelihood ratio was 6.25 (95% confidence interval: 1.788-21.845), and sensitivity of EOB-MRI for detecting pT2 HCC was 86.2% when two or three of these MRI features were present. Small tumor size and hypointense rim in the HB phase were regarded as benign features. Small HCCs with hypointense rim but not associated with aggressive features were mostly pT1 lesions (specificity, 100%).
Imaging features on EOB-MRI could potentially be used to predict the pathologic stage of solitary HCC (cT1) as pT1 or pT2.
Core tip: Gadoxetic acid-enhanced-magnetic resonance imaging (EOB-MRI) has been shown to outperform other hepatocellular carcinoma (HCC) diagnostic tools. Our aim was to determine whether EOB-MRI findings could be used to predict pathologic stage T2 in patients with solitary HCC, clinical stage T1 (cT1). EOB-MRI was performed in 114 patients with solitary HCC [39 with pathologic stage T2 (pT2) and 75 with pT1]. Large tumor size, corona enhancement, and peritumoral hypointensity in hepatobiliary phase images were associated with high risk of pT2 HCC. The sensitivity of EOB-MRI for detecting pT2 HCC was 86.2% when two or three of these MRI features were present.