A preoperative model based on gadobenate-enhanced MRI for predicting microvascular invasion in hepatocellular carcinomas (≤ 5 cm)

Abstract

Purpose: The present study aimed to develop and validate a preoperative model based on gadobenate-enhanced magnetic resonance imaging (MRI) for predicting microvascular invasion (MVI) in patients with hepatocellular carcinoma (HCC) size of ≤5 cm. In order to provide preoperative guidance for clinicians to optimize treatment options.

Methods: 164 patients with pathologically confirmed HCC and preoperative gadobenate-enhanced MRI from July 2016 to December 2020 were retrospectively included. Univariate and multivariate logistic regression (forward LR) analyses were used to determine the predictors of MVI and the model was established. Four-fold cross validation was used to verify the model, which was visualized by nomograms. The predictive performance of the model was evaluated based on discrimination, calibration, and clinical utility.

Results: Elevated alpha-fetoprotein (HR 1.849, 95% CI: 1.193, 2.867, P=0.006), atypical enhancement pattern (HR 3.441, 95% CI: 1.523, 7.772, P=0.003), peritumoral hypointensity on HBP (HR 7.822, 95% CI: 3.317, 18.445, P<0.001), and HBP hypointensity (HR 3.258, 95% CI: 1.381, 7.687, P=0.007) were independent risk factors to MVI and constituted the HBP model. The mean area under the curve (AUC), sensitivity, specificity, and accuracy values for the HBP model were as follows: 0.830 (95% CI: 0.784, 0.876), 0.71, 0.78, 0.81 in training set; 0.826 (95% CI:0.765, 0.887), 0.8, 0.7, 0.79 in test set. The decision curve analysis (DCA) curve showed that the HBP model achieved great clinical benefits.

Conclusion: In conclusion, the HBP imaging features of Gd-BOPTA-enhanced MRI play an important role in predicting MVI for HCC. A preoperative model, mainly based on HBP imaging features of gadobenate-enhanced MRI, was able to excellently predict the MVI for HCC size of ≤5cm. The model may help clinicians preoperatively assess the risk of MVI in HCC patients so as to guide clinicians to optimize treatment options.

Keywords: gadobenate dimeglumine; hepatocellular carcinoma; magnetic resonance imaging; microvascular invasion; nomogram.

Figure 1

The workflow of patient selection for this study.

Figure 2

Representative images of MVI positive cases: A 71-year-old male with elevated AFP, Gd- BOPTA MRI detected a solid lesion in hepatic segment VI (A), restricted diffusion (B), atypical enhancement pattern without “wash-in” (C–E), with the architectures of peritumoral enhancement on arterial phase images (C), incomplete capsule enhancement on portal venous phase and transitional phase images (D, E), and peritumoral hypointensity on hepatobiliary phase (F).

Figure 3

Representative images of MVI positive cases: A 60-year-old male with elevated AFP, Gd-BOPTA MRI detected a solid lesion in hepatic segment V (A), restricted diffusion (B), atypical enhancement pattern without “wash-in” (C–E), incomplete capsule enhancement on portal venous phase and transitional phase images (D, E), and homogeneous HBP hypointensity (F).

Figure 4

Representative images of MVI negative case: A 61-year-old male, the lesion located at hepatic segment VIII (A), restricted diffusion (B), but showed a well-circumscribed smooth tumor edge and complete capsule enhancement (D, E), typical enhancement pattern with “wash-in” and “wash-out” (C–E), without peritumoral enhancement on arterial phase images (C) and mild HBP hypointensity (F).

Figure 5

The nomogram and receiver operating characteristic curves for predicting MVI: (A) HBP model visualized by nomograms; (B) Decision curve analysis (DCA) of HBP model; (C) Training set’s receiver operating characteristic (ROC) curves of stratified 4-fold; (D) Test set’s ROC curves of stratified 4-fold.