Preoperative MRI-based prediction and risk stratification of very early recurrence in intrahepatic...

To establish and validate a preoperative MRI-based model to predict very early recurrence (VER, ≤6 months) of intrahepatic mass-forming cholangiocarcinoma (IMCC) following curative resection.

This multicenter study enrolled 228 patients who underwent curative resection for IMCC between May 2019 and January 2024. Participants were randomly allocated to a training cohort (n = 160) and a validation cohort (n = 68). Independent predictors of VER were identified using Cox regression analysis and integrated into a prediction nomogram. The discriminative performance was evaluated and recurrence-free survival (RFS) between low-and high-risk groups was compared using Kaplan-Meier analysis.

VER was observed in 52 patients (32.5%) and 28 patients (41.2%) in the training and validation cohorts. Tumor multiplicity (HR: 1.858, 95% CI: 1.017-3.394, p = 0.044), arterial edge enhancement ratio (HR: 0.012, 95% CI: 0.001-0.423; p = 0.015), and intrahepatic duct dilatation (HR: 2.367, 95% CI: 1.332-4.205; p = 0.003) were identified as independent predictors of VER. The area under the curve (AUC) of nomogram was 0.815 (95 % CI: 0.746-0.894) and 0.827 (95% CI: 0.726-0.927) in the training and validation cohorts. RFS rate was significantly lower in the high-risk group compared to the low-risk group in the training cohort (27.8% vs. 79.0%; p < 0.001) and the validation cohort (18.8% vs. 71.2%; p < 0.001).

The preoperative MRI-based model, incorporating tumor multiplicity, arterial edge enhancement ratio, and intrahepatic duct dilatation can effectively predict VER with risk stratification in IMCC patients.