Preoperative MRI features and clinical factors for predicting early recurrence of hepatocellular carcinoma after hepatectomy.

Introduction: Early recurrence after hepatectomy remains a major obstacle to durable disease control in hepatocellular carcinoma (HCC). This study developed and externally validated a prediction model based on preoperative MRI features and clinical laboratory factors for early recurrence after hepatectomy for HCC, defined as recurrence within 24 months after surgery. Methods: This two-center retrospective cohort study included adult patients with pathologically confirmed HCC who underwent curative hepatectomy and contrast-enhanced liver MRI within 2 months before surgery between January 2018 and December 2025. The Affiliated Hospital of North Sichuan Medical College served as the development cohort, and Suining Central Hospital served as the external validation cohort. Candidate clinical and MRI predictors were evaluated in the development cohort. A Cox regression model was developed, internally validated with 1000 bootstrap resamples, and directly applied to the external validation cohort without refitting. Results: The final analysis cohort included 320 patients, including 258 in the development cohort and 62 in the external validation cohort. Overall, 183 patients (57.2%) experienced early recurrence. The final combined Cox model retained log(PIVKA-II), tumor size >5 cm, satellite nodule, peritumoral hypointensity on portal venous phase images, intrahepatic vessel invasion, and incomplete capsule. In the development cohort, the apparent C-index was 0.756, and the bootstrap-corrected 24-month AUC was 0.829. In the external validation cohort, the C-index was 0.892, the 24-month AUC was 0.978, and the Brier score was 0.087. Calibration analysis indicated imperfect absolute risk calibration, with a calibration slope of 2.705 and an intercept of -1.288; grouped calibration suggested risk overestimation in the lower predicted-risk range. The development cohort-derived cutoff of 0.584 separated patients with different early recurrence risks in both cohorts. In the external validation cohort, only one early recurrence event occurred in the low-risk reference group, so the risk-stratification HR should be interpreted as directional separation rather than as a stable clinical effect-size estimate. Conclusion: This preoperative MRI-clinical Cox model showed good predictive performance for early recurrence after hepatectomy for HCC and high discrimination in external validation. Its calibration and clinical utility require further evaluation in larger prospective multicenter cohorts.