For newly diagnosed and histologically confirmed nasopharyngeal carcinoma patients staged as T1-4, N0-1/N3, M0 (AJCC 8th), if no metastatic lymph nodes were found on MRI according to the current diagnostic criteria, but there were small lymph nodes with a minimal axial diameter ≥ 5 mm (6 mm for lymph node in level II) on at least one side of the patient's neck, they will be eligible for this study. The MRI image of the small lymph nodes will be evaluated in details by experienced radiologists. Contrast-enhanced ultrasonography with specific ultrasound contrast agents (Sonazoid) and ultrasound-guided lymph node aspiration will be performed. Subsequently, the lymph node tissue obtained from ultrasound-guided lymph node aspiration will be subjected to pathologic evaluation. Using the pathologic diagnosis of the lymph node as the gold standard, diagnostic performance of MRI and contrast-enhanced ultrasonography will be evaluated. Resonable criteria to diagnose small cervical lymph node metastases by combining MRI scanning and contrast-enhanced ultrasonography will be explored. And the diagnostic performance of the criteria will be evaluated.
This is a single-center diagnostic accuracy study, with the purpose to define the criteria to diagnose small cervical lymph node metastases in patients with nasopharyngeal carcinoma by combining MRI scanning and contrast-enhanced ultrasonography and evaluate the diagnostic performance of the criteria.