Comparing Primary Tumors and Metastatic Nodes in Head and Neck Cancer Using Intravoxel Incoherent Motion Imaging: A Preliminary Experience

Objective: This study aimed to use intravoxel incoherent motion (IVIM) imaging for investigating differences between primary head and neck tumors and nodal metastases and to evaluate IVIM efficacy in predicting outcome. Methods: Sixteen patients with head and neck cancer underwent IVIM diffusion-weighted imaging on a 1.5-T magnetic resonance imaging scanner. The significance of parametric difference between primary tumors and metastatic nodes were tested. Probabilities of progression-free survival and overall survival were estimated using the Kaplan-Meier method. Results: In comparison with metastatic nodes, the primary tumors had significantly higher vascular volume fraction (f) (P < 0.0009) and lower diffusion coefficient (D) (P < 0.0002). Patients with lower SD for D had prolonged progression-free survival and overall survival (P < 0.05). Conclusions: Pretreatment IVIM measures were feasible in investigating the physiologic differences between the 2 tumor tissues. After appropriate validation, these findings might be useful in optimizing treatment planning and improving patient care.