Abstract
Background: In daily practice of the management of head and neck tumors, it is often very challenging to separate nontumorous neck lymph nodes from metastatic nodes via imaging. The aim of our study was to assess the potential role of dynamic contrast-enhanced magnetic resonance imaging and diffusion-weighted magnetic resonance imaging to help distinguish nontumorous neck lymph nodes from metastatic nodes 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 and 35 metastatic lymph nodes, were examined retrospectively. After clinical examination, the patients underwent head and neck multiparametric magnetic resonance imaging, including standard T1-weighted and T2-weighted sequences and functional dynamic contrast enchanced-MRI and diffusion weighted-MRI measurements, too. After multiparametric magnetic resonance imaging, the nodes, which were difficult to locate on ultrasound mainly due to their size, underwent a magnetic resonance imaging/ultrasound fusion imaging. All the examined nodes were easily identifiable on nonfusion ultrasound. Fine-needle aspiration biopsies, along with core biopsies in some, and surgical samples in some others were obtained from these nodes. Time intensity curves were generated from the dynamic contrast enchanced-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 nontumorous neck lymph nodes and the metastatic nodes. Although apparent diffusion coefficient values were not significantly different between nontumorous neck lymph nodes and metastatic nodes, metastatic nodes had lower apparent diffusion coefficient values while nontumorous neck lymph nodes had higher apparent diffusion coefficient 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 can be used to further characterize nontumorous neck lymph nodes and metastatic nodes in vivo and to increase diagnostic accuracy.