MRI Radiomics-Based Evaluation of Vessels Encapsulating Tumor Clusters and Microvascular Invasion in Hepatocellular Carcinoma.

[PURPOSE] This study aimed to develop a radiomics model based on dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) for the preoperative prediction of two distinct histopathological vascular patterns in hepatocellular carcinoma (HCC): vessels encapsulating tumor clusters (VETC) and microvascular invasion (MVI). In addition, the study evaluated the prognostic significance of these vascular patterns in predicting postoperative outcomes in patients with HCC.

[PATIENTS AND METHODS] A total of 306 patients with HCC who underwent radical resection at two medical centers were retrospectively included. Patients from Center 1 were randomly assigned to a training cohort and an internal validation cohort at a ratio of 7:3, while patients from Center 2 comprised the external validation cohort. Radiomics features were extracted from the arterial phase (AP), portal venous phase (PP), and delayed phase (DP) DCE-MRI images, including intratumoral, peritumoral, and fused intra-peritumoral regions. Radiomics models were constructed based on these features, and the optimal model was subsequently integrated with clinical variables to establish a combined clinical-radiomics model.

[RESULTS] For predicting VETC and/or MVI (defined as VM patterns), the combined model achieved area under the curve (AUC) values of 0.857 in the training cohort, 0.761 in the internal validation cohort, and 0.723 in the external validation cohort. Calibration and decision curve analysis (DCA) indicated acceptable calibration performance and potential clinical utility of the combined model. Both pathological VM positivity and model-predicted VM positivity were significantly associated with early recurrence (ER) and shorter disease-free survival (DFS).

[CONCLUSION] The clinical-radiomics combined model based on DCE-MRI holds potential value as a noninvasive preoperative approach for evaluating VM patterns and postoperative prognosis in patients with HCC.