Fluorodeoxyglucose-Positron Emission Tomography/Computed Tomography After Concurrent Chemoradiotherapy in Locally Advanced Head-and-Neck Squamous Cell Cancer: The ECLYPS Study

PurposeTo assess the standardized implementation and reporting of surveillance [18F]fluorodeoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT) scan of the neck in locoregionally advanced head-and-neck squamous cell carcinoma (LAHNSCC) after concurrent chemoradiotherapy (CCRT).Patients and MethodsWe performed a prospective multicenter study of FDG-PET/CT scanning 12 weeks after CCRT in newly diagnosed patients with LAHNSCC (stage IVa/b) that used standardized reconstruction and Hopkins reporting criteria. The reference standard was histology or > 12 months of clinical follow-up. The primary outcome measure was the negative predictive value (NPV) of FDG-PET/CT scans and other supporting diagnostic test characteristics, including time dependency with increasing follow-up time.ResultsOf 152 patients, 125 had adequate primary tumor control after CCRT and entered follow-up (median, 20.4 months). Twenty-three (18.4%) had residual neck disease. Overall, NPV was 92.1% (95% CI, 86.9% to 95.3%;...