Response evaluation of cervical lymph nodes after chemoradiation in patients with head and neck cancer - does additional [18F]FDG-PET-CT help?

• DOI: 10.1186/s40644-020-00345-8
• Publication Date: 2020-09-29T12:03:11Z
• Authors: Daniel Dejaco; Christian Uprimny; Gerlig Widmann; David Riedl; Patrizia Moser; Christoph Arnold; Teresa Bernadette...; Barbara Kofler; Volker Hans Schar...; Irene Virgolini; Herbert Riechelmann
• Keywords: PET-CT; Fluorodeoxyglucose

Abstract Background Contrast-enhanced high-resolution computed tomography (contrast-CT) is a standard imaging modality following primary concurrent radiochemotherapy (RCT) for response evaluation in patients with head and neck squamous cell carcinoma (HNSCC). We investigated the additional benefit of Fluorine-18-fluorodeoxyglucose ([18F]FDG) - positron emission (PET-CT), if complete (CR) based on contrast-CT was considered unsafe by interdisciplinary tumor board (ITB). Methods In retrospective observational study, recorded institutional registry incident advanced HNSCC first line treatment RCT were eligible. If results equivocal or positive at evaluation, dissection (ND) scheduled. While waiting ND, [18F]FDG-PET-CT performed addition. The histopathological outcome ND served as reference criterion. Accuracy parameters including sensitivity, specificity, accuracy, predictive value (PPV) negative (NPV) both, PET-CT, main parameters. Results A total 41 posttreatment eligible post-RCT-ND. Of these, 33 received an prior to surgery. Median interval between completion ([18F]FDG)-PET-CT 10 weeks. Vital persistent histopathologically found 13 contrast-CT. For [18F]FDG-PET-CT, sensitivity 92.3 69.2% did not differ statistically significantly ( p = 0.250) whereas specificity higher compared (80% vs. 25%, 0.001). PPV NPV 31.7, 12.0,96.7 78.9, 27.8,95.0%, respectively. Conclusion improve exclusion vital after comparison alone. However, considerably better indicator persistent, than If, result, uncertain contrast CT had been omitted, nodal disease would have delayed 3 patients. On other hand, only patients, unnecessary avoided 11 20