Ultrasound Is Beneficial to Determine Lymphadenopathy in Oral Cancer Patients after Radiotherapy

The present study aimed to investigate whether the addition of ultrasound (US) +/- fine needle aspiration (FNA) to magnetic resonance imaging (MRI) or computed tomography (CT) improves the diagnostic accuracy in assessing neck lymphadenopathy in oral cancer patients after neck irradiation. We retrospectively reviewed oral cancer patients who had neck lymphadenopathy after radiotherapy (RT) or chemoradiation therapy (CRT) from February 2008 to November 2019. The following diagnostic modalities were assessed: (1) MRI/CT, (2) MRI/CT with a post-RT US predictive model, and (3) MRI/CT with US + FNA. The receiver operating characteristic (ROC) curves were used to assess the diagnostic performance. A total of 104 irradiation-treated oral cancer patients who subsequently had neck lymphadenopathy were recruited and analyzed. Finally, there were 68 (65%) malignant and 36 (35%) benign lymphadenopathies. In terms of the diagnostic performance, the area under the ROC curves (C-statistics) was 0.983, 0.920, and 0.828 for MRI/CT with US + FNA, MRI/CT with a post-RT US predictive model, and MRI/CT, respectively. The addition of US to MRI/CT to evaluate cervical lymphadenopathy could achieve a better diagnostic accuracy than MRI/CT alone in oral cancer patients after neck irradiation.