Prognostic value of IVIM-DWI parameters for overall and recurrence-free survival in resected esophageal squamous cell carcinoma

PURPOSE: Prognostic stratification after surgical resection remains challenging in esophageal squamous cell carcinoma (ESCC), as pathological staging cannot quantitatively capture intratumoral heterogeneity. Intravoxel incoherent motion diffusion-weighted imaging (IVIM-DWI) enables noninvasive quantification of tumor diffusion and perfusion characteristics. To evaluate the prognostic value of IVIM-derived parameters for predicting overall survival (OS) and recurrence-free survival (RFS) in resected ESCC and to compare their performance with conventional clinicopathological factors. METHODS: Eighty patients with pathologically confirmed ESCC who underwent preoperative IVIM-DWI MRI and surgical resection were retrospectively included. IVIM parameters (apparent diffusion coefficient (ADC), the true diffusion coefficient (D), pseudo-diffusion coefficient (D*), and perfusion fraction (f)) were extracted using maximum-diameter and whole-volume tumor delineation. Cox regression with stepwise selection was performed to identify prognostic factors. Time-dependent ROC analysis was used to evaluate the predictive performance of clinicopathological, IVIM-based, and combined models, and Kaplan-Meier survival analysis was applied to assess risk stratification based on model-derived risk scores. RESULTS: IVIM-based models showed superior prognostic performance compared with clinicopathological models, particularly for OS. For 1-year OS prediction, the IVIM model (maximum-diameter) achieved an AUC of 0.776 and an accuracy of 0.725, while the combined model further improved performance (AUC 0.827, accuracy 0.812). Similar advantages were observed for RFS, with the combined model yielding a 1-year AUC of 0.825 and accuracy of 0.812, and maintaining the best performance at 3 years for both OS (AUC 0.719, accuracy 0.738) and RFS (AUC 0.850, accuracy 0.825). In addition, the derived risk scores enabled effective risk stratification, with Kaplan-Meier analyses demonstrating significant survival differences between risk groups (log-rank P < 0.001). CONCLUSION: IVIM-derived parameters provide complementary prognostic information beyond conventional pathological staging in ESCC and may improve postoperative risk stratification when integrated with clinicopathological factors.