title: Post-treatment 18F-FDG-PET/CT versus contrast-enhanced CT in patients with oropharyngeal squamous cell carcinoma: comparative effectiveness study.
abstract: OBJECTIVE
  To compare the accuracy of same-day therapy-assessment PET/computed tomography (PET/CT) and conventional contrast-enhanced computed tomography (CECT) in patients with oropharyngeal squamous cell carcinoma (OPSCC).
  
  
  METHODS
  A total of 110 (95 men and 15 women; mean age 59 years) patients with biopsy-proven OPSCC were evaluated with same-day PET/CT and CECT pair scans as part of follow-up therapy assessment. Scans were performed within 6 months after the completion of primary treatment (median time: 3.1 months; range: 0.5-6 months). PET/CT and CECT scans were reviewed retrospectively for residual primary site disease, and right and left cervical lymph node involvement. Histopathology or 6 month clinical/imaging follow-up were used as the gold standard. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy were calculated for the primary site and cervical nodal disease.
  
  
  RESULTS
  Of 110 OPSCC patients, 90.9% were human papilloma virus positive, 80.8% were stage 4, and 76.4% received chemoradiation as the primary treatment. The sensitivity, specificity, PPV, NPV, and accuracy of PET/CT and CECT were similar in the evaluation of the primary cancer site (PET/CT: 75.0, 91.5, 25.0, 99.0, and 90.9, respectively, versus CECT: 75.0, 90.6, 23.1, 99.0, and 90.0, respectively). In evaluating cervical lymph node involvement, PET/CT appeared to have higher accuracy (96.8 vs. 81.7%), specificity (97.7 vs. 81.7%), and PPV (45.8 vs. 16.5%), comparable NPV (99.4% for both), and lower sensitivity (65 vs. 75%) compared with same-day CECT.
  
  
  CONCLUSIONS
  Same-day PET/CT and CECT scans had comparable accuracy in the evaluation of primary tumor sites after completion of therapy in patients with OPSCC. PET/CT showed higher accuracy in the evaluation of cervical lymph node involvement.
authors.affiliation: aRussell H Morgan Department of Radiology and Radiological Sciences, Johns Hopkins University, Baltimore, Maryland bDepartment of Radiology cAdvanced Imaging Research Institute dDepartment of Clinical Sciences eDepartment of Biomedical Engineering, University of Texas Southwestern Medical Center, Dallas, Texas, USA.
authors.forename: Mehdi
authors.initials: M
authors.lastname: Taghipour
authors.forename: Esther
authors.initials: E
authors.lastname: Mena
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Kruse
authors.forename: Sara
authors.initials: S
authors.lastname: Sheikhbahaei
authors.forename: Rathan M
authors.initials: RM
authors.lastname: Subramaniam
mesh_terms: D002294:Carcinoma, Squamous Cell / Q000000981:diagnostic imaging* / Q000628:therapy; D003287:Contrast Media; D005260:Female; D019788:Fluorodeoxyglucose F18; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009959:Oropharyngeal Neoplasms / Q000000981:diagnostic imaging* / Q000628:therapy; D000072078:Positron Emission Tomography Computed Tomography / Q000379:methods*; D012680:Sensitivity and Specificity
chemical_list: D003287:Contrast Media; D019788:Fluorodeoxyglucose F18