MRI imaging features for evaluating the efficacy and prognosis of TACE combined with targeted immunotherapy in unresectable hepatocellular carcinoma.

[PURPOSE] To identify significant MRI features associated with the efficacy and prognosis of TACE Combined with Targeted therapy and Immunotherapy (TTI) in patients with unresectable Hepatocellular Carcinoma(uHCC) and to assess the distribution of LI-RADS category assignments.

[MATERIALS AND METHODS] This retrospective study included 134 uHCC patients who underwent baseline MRI prior to TTI. Patients were randomly divided into a training cohort (n = 93) and a validation cohort (n = 41). Treatment response was evaluated using mRECIST criteria. Multivariate logistic regression was performed to identify predictors of objective response. Cox regression models were used to identify prognostic factors for progression-free survival (PFS) and overall survival (OS). Nomograms were constructed and evaluated via receiver operating characteristic (ROC) curves, calibration plots, and decision curve analysis (DCA).

[RESULTS] LI-RADS tumor in vein (LR-TIV) and ascites were independent predictors of treatment response. The predictive model achieved an area under the curve (AUC) of 0.692 (training) and 0.839 (validation). Multivariate Cox analysis identified objective response according to mRECIST, number of interventional procedures, and enhancing pseudocapsule as independent predictors of PFS, while OR-mRECIST, nonrim arterial phase hyperenhancement (APHE), intratumoral hemorrhage, and ascites were significantly associated with OS. The models demonstrated robust risk stratification and clinical utility.

[CONCLUSION] Pre-treatment LI-RADS MRI features, particularly LR-TIV and nonrim APHE, combined with clinical variables, provide valuable prognostic and predictive information in uHCC patients undergoing TTI. These models may support individualized treatment strategies and inform clinical decision-making.