title: Contrast-enhanced ¹⁸F-FDG-PET/CT for the assessment of necrotic lymph node metastases.
abstract: BACKGROUND
  Cystic lymph node metastasis (CLNM) is commonly found in human papillomavirus (HPV)-associated tonsillar squamous cell carcinoma (SCC). The aim of this study was to compare the accuracy in detecting cystic lymph node metastasis from tonsillar SCC between contrast-enhanced CT, ¹⁸F- fluorodeoxyglucose-positron emission tomography (FDG-PET), non-enhanced ¹⁸F-FDG-PET/CT, and contrast-enhanced ¹⁸F-FDG-PET/CT.
  
  
  METHODS
  Thirty-four patients with a tonsillar SCC undergoing a pretreatment contrast-enhanced ¹⁸F-FDG-PET/CT followed by a neck dissection as a standard of reference were included. The contrast-enhanced CT part, the ¹⁸F-FDG-PET part, the non-enhanced ¹⁸F-FDG-PET/CT part, and the contrast-enhanced ¹⁸F-FDG-PET/CT were assessed separately for correct N classification and the differentiation of N0 versus N+. RESULTS.: Contrast-enhanced ¹⁸F-FDG-PET/CT, non-enhanced ¹⁸F-FDG-PET/CT, and contrast-enhanced CT are equally accurate for correct neck staging. Regarding pN0 versus pN+, contrast-enhanced CT and contrast-enhanced ¹⁸F-FDG-PET/CT are superior to non-enhanced ¹⁸F-FDG-PET/CT (p = .017).
  
  
  CONCLUSIONS
  Contrast-enhanced CT and contrast-enhanced ¹⁸F-FDG-PET/CT perform equally and better than non-enhanced ¹⁸F-FDG-PET/CT in detecting CLNM in tonsillar SCC. Therefore, in patients scheduled for ¹⁸F-FDG-PET/CT, we strongly suggest performing a contrast-enhanced ¹⁸F-FDG-PET/CT, which is not routine in most centers.
authors.affiliation: Department of Otolaryngology, Head and Neck Surgery, University Hospital Zurich, CH-8091 Zurich, Switzerland. stephan.haerle@usz.ch
authors.forename: Stephan K
authors.initials: SK
authors.lastname: Haerle
authors.forename: Klaus
authors.initials: K
authors.lastname: Strobel
authors.forename: Nader
authors.initials: N
authors.lastname: Ahmad
authors.forename: Alex
authors.initials: A
authors.lastname: Soltermann
authors.forename: Daniel T
authors.initials: DT
authors.lastname: Schmid
authors.forename: Sandro J
authors.initials: SJ
authors.lastname: Stoeckli
mesh_terms: D000368:Aged; D002294:Carcinoma, Squamous Cell / Q000000981:diagnostic imaging* / Q000556:secondary* / Q000601:surgery; D015331:Cohort Studies; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008198:Lymph Nodes / Q000000981:diagnostic imaging* / Q000473:pathology; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009336:Necrosis / Q000473:pathology; D009367:Neoplasm Staging / Q000379:methods; D049268:Positron-Emission Tomography / Q000379:methods; D011300:Preoperative Care / Q000379:methods; D011379:Prognosis; D011856:Radiographic Image Enhancement; D012189:Retrospective Studies; D016019:Survival Analysis; D014057:Tomography, X-Ray Computed / Q000379:methods; D014067:Tonsillar Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery
chemical_list: D019788:Fluorodeoxyglucose F18