Dynamic Contrast-Enhanced and Diffusion-Weighted MRI Biomarkers for Differentiating Metastatic from Nontumorous Neck Lymph Nodes in Head and Neck Cancer,

Abstract

Background In daily practice of the management of head and neck tumors, it is often very challenging to separate nontumorous neck lymph nodes (NTN) from metastatic nodes (MN) via imaging. The aim of our study was to assess the potential role of dynamic contrast-enhanced magnetic resonance imaging (DCE- MRI) and diffusion-weighted magnetic resonance imaging (DW-MRI) to help distinguish NTNs from MNs in patients with head and neck cancer so that neck node dissection can be selective rather than elective. Methods A total of 47 nodes, 12 nontumorous nodes (NTN) and 35 metastatic lymph nodes (MN), were examined. After clinical examination, the patients underwent head and neck multiparametric magnetic resonance imaging (MP-MRI), including standard T1-weighted (T1-w) and T2-weighted (T2- w) sequences and functional DCE-MRI and DW-MRI measurements, too. After MP-MRI, the nodes, which were difficult to locate on ultrasound (US) mainly due to their size, underwent a magnetic resonance imaging/ultrasound (MRI/US) fusion imaging. All the examined nodes were easily identifiable on nonfusion US. Fine-needle aspiration biopsies, along with core biopsies in some, and surgical samples in some others were obtained from these nodes. Time intensity curves (TICs) were generated from the DCE-MRI sequence, and various curve parameters were analyzed. The apparent diffusion coefficient (ADC) values were calculated from the DW-MRI sequence. The results were analyzed using various statistical methods. Results Several DCE-MRI parameters significantly differed between the NTNs and the MNs. Although ADC values were not significantly different between NTNs and MNs, MNs had lower ADC values while NTNs had higher ADC values. Conclusion Although morphological imaging and biopsies remain the gold standard for analyzing neck lymph nodes in patients with head and neck cancer, according to our study and existing literature, multiparametric magnetic resonance imaging (MP-MRI) can be used to further characterize NTN’s and MN’s in vivo and to increase diagnostic accuracy.