ORIGINAL ARTICLE 18F-FDG-PET/CT VERSUS PANENDOSCOPY FOR THE DETECTION OF SYNCHRONOUS SECOND PRIMARY TUMORS IN PATIENTS WITH HEAD AND NECK

Abstract: Background. This study assesses the additional value of 18F-fluoro-2-deoxy-D-glucose positron emission tomog-raphy/CT (18F-FDG-PET/CT) with respect to synchronous pri-maries in patients undergoing panendoscopy for staging of head and neck squamous cell carcinoma. Methods. In all, 311 patients underwent both modalities. Cytology, histology, and/or clinical/imaging follow-up served as reference standard. Results. The prevalence of second primary tumors detected by panendoscopy was 4.5%, compared with 6.1 % detected by 18F-FDG-PET/CT. The sensitivity for panendoscopy was 74%, the specificity was 99.7%, the positive predictive value (PPV) was 93%, and the negative predictive value (NPV) was 98%. The sensitivity for 18F-FDG-PET/CT was 100%, the specificity was 95.7%, the PPV was 59%, and the NPV was 100%. Conclusions. 18F-FDG-PET/CT is superior to panendo-scopy. With a negative 18F-FDG-PET/CT, the extent of endos-copy can be reduced to the area of the primary tumor. Due to the costs, 18F-FDG-PET/CT is recommended only in advanced disease to assess potential distant disease. In early-stage can-cer, panendoscopy is accurate enough to rule out secondar