Treatment evaluation of metastatic lymph nodes after concurrent chemoradiotherapy in patients with head and neck squamous cell carcinoma.

BACKGROUND Concurrent chemoradiotherapy (CCRT) is used to treat advanced head and neck cancer. The accuracy of evaluating lymph nodes metastases following CCRT is important for subsequent therapy. PATIENTS AND METHODS Patients were divided into two groups, the complete response (CR) and the non-CR groups, as determined by imaging and fine-needle aspiration cytology (FNAC) performed 4-8 weeks after the CCRT, and the findings were compared with the clinical characteristics. RESULTS The sensitivity and the specificity of each evaluation method were as follows: 52.9% and 74.2%, respectively, for computer tomography (CT) and magnetic resonance imaging (MRI); 88.2% and 66.1% for ultrasonography (US); 35.3% and 96.0% for fluorodeoxyglucose-positron emission tomography (FDG-PET) or PET-CT; and 71.4% and 95.6% for FNAC. CONCLUSION To evaluate the response of lymph node(s) treated by CCRT, US is useful as a positive screening tool and FDG-PET and PET-CT as negative screening tools. FNAC is useful in evaluating suspicious lymph nodes in both positive and negative cases.