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

5 years ago

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

Hoekstra OS, Lenssen O, Stroobants S, Helsen N, Meersschout SAE, Hakim S, Van den Weyngaert D, ECLYPS investigators, van Dinther J, Van Laer CG, De Bree R, Carp L, Hutsebaut I, Martens MJ, Maes ALM, Debruyne PR, Van den Wyngaert T, Vermorken JB

Purpose To 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 Methods We 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. Results Of 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%; null hypothesis: NPV = 85%; P = .012) with sensitivity of 65.2% (95% CI, 44.9% to 81.2%), specificity of 91.2% (95% CI, 84.1% to 95.3%), positive predictive value of 62.5% (95% CI, 45.5% to 76.9%), and accuracy of 86.4% (95% CI, 79.3% to 91.3%). Sensitivity was time dependent and high for residual disease manifesting up to 9 months after imaging but lower (59.7%) for disease detected up to 12 months after imaging. Standardized reporting criteria reduced the number of equivocal reports (95% CI for the difference, 2.6% to 15.0%; P = .003). Test characteristics were not improved with the addition of lymph node CT morphology criteria. Conclusion FDG-PET/CT surveillance using Hopkins criteria 12 weeks after CCRT is reliable in LAHNSCC except for late manifesting residual disease, which may require an additional surveillance scan at 1 year after CCRT to be detected.

Publisher URL: https://www.ncbi.nlm.nih.gov/pubmed/28854069

DOI: PubMed:28854069