Preoperative MRI-based scoring system for prediction of microvascular invasion in intrahepatic mass-forming cholangiocarcinoma ≤5 cm: A multicenter study.

OBJECTIVES

To establish and externally validate a preoperative MRI-based risk scoring system for MVI prediction in IMCC≤5 cm, and to evaluate its prognostic value.

METHODS

This multicenter retrospective study enrolled 171 patients with pathologically confirmed IMCC (≤5 cm) from four institutions who underwent curative surgical resection. Patients were divided into training (n = 122) and external validation (n = 49) cohorts. Univariable and multivariable logistic regression analyses were performed to identify independent predictors of MVI. A scoring system was established by incorporating the independent predictors based on logistic regression coefficients. According to this scoring system, patients were stratified into low- and high-risk MVI groups and disease-free survival (DFS) was analyzed by Kaplan-Meier survival analysis.

RESULTS

In the multivariable analysis, non-smooth tumor margin (OR = 4.140; p = 0.005), arterial phase (AP) peritumoral enhancement (OR = 6.589; p < 0.001), and arterial edge enhancement ratio (AEER; OR = 0.916; p < 0.001) were included as independent predictors of MVI. The scoring system demonstrated high predictive accuracy, with AUCs of 0.837 in the training cohort and 0.813 in the external validation cohort. IMCC patients at high risk exhibited significantly shorter DFS compared to those at low risk for MVI in both cohorts (p < 0.05).

CONCLUSION

The preoperative MRI-based scoring system incorporating tumor margin, AP peritumoral enhancement, and AEER can effectively predict MVI in patients with IMCC ≤5 cm, providing a valuable predictive tool for risk stratification and prognosis assessment.