title: Impact of FDG-PET/CT imaging on nodal staging for head-and-neck squamous cell carcinoma.
abstract: OBJECTIVE
  To evaluate the impact of 18F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) imaging on nodal staging for head-and-neck squamous cell carcinoma (SCC).
  
  
  METHODS
  The study population consisted of 23 patients with head-and-neck SCC who were evaluated with FDG-PET/CT and went on to neck dissection. Two observers consensually determined the lesion size and maximum standardized uptake value (SUVmax) and compared the results with pathologic findings on nodal-level involvement. Two different observers (A and B) independently performed three protocols for clinical nodal staging. Methods 1, 2, and 3 were based on conventional modalities, additional visual information from FDG-PET/CT images, and FDG-PET/CT imaging alone with SUV data, respectively.
  
  
  RESULTS
  All primary tumors were visualized with FDG-PET/CT. Pathologically, 19 positive and 93 negative nodal levels were identified. The SUVmax overlapped in negative and positive nodes <15 mm in diameter. According to receiver operating characteristics analysis, the size-based SUVmax cutoff values were 1.9, 2.5, and 3.0 for lymph nodes <10 mm, 10-15 mm, and >15 mm, respectively. These cutoff values yielded 79% sensitivity and 99% specificity for nodal-level staging. For Observer A, the sensitivity and specificity in Methods 1, 2, and 3 were 68% and 94%, 68% and 99%, and 84% and 99%, respectively, and Method 3 yielded significantly higher accuracy than Method 1 (p = 0.0269). For Observer B, Method 3 yielded the highest sensitivity (84%) and specificity (99%); however, the difference among the three protocols was not statistically significant.
  
  
  CONCLUSIONS
  Imaging with FDG-PET/CT with size-based SUVmax cutoff values is an important modality for radiation therapy planning.
authors.affiliation: Department of Radiation Oncology, Kumamoto University Hospital, Kumamoto, Japan. murakami@kaiju.medic.kumamato-u.ac.jp
authors.forename: Ryuji
authors.initials: R
authors.lastname: Murakami
authors.forename: Hideaki
authors.initials: H
authors.lastname: Uozumi
authors.forename: Toshinori
authors.initials: T
authors.lastname: Hirai
authors.forename: Ryuichi
authors.initials: R
authors.lastname: Nishimura
authors.forename: Shinya
authors.initials: S
authors.lastname: Shiraishi
authors.forename: Kazutoshi
authors.initials: K
authors.lastname: Ota
authors.forename: Daizo
authors.initials: D
authors.lastname: Murakami
authors.forename: Seiji
authors.initials: S
authors.lastname: Tomiguchi
authors.forename: Natsuo
authors.initials: N
authors.lastname: Oya
authors.forename: Shigehiko
authors.initials: S
authors.lastname: Katsuragawa
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Yamashita
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002294:Carcinoma, Squamous Cell / Q000000981:diagnostic imaging* / Q000556:secondary; D005260:Female; D019788:Fluorodeoxyglucose F18; D006258:Head and Neck Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D006801:Humans; D008207:Lymphatic Metastasis / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D037981:Neck Dissection; D009367:Neoplasm Staging / Q000379:methods; D015588:Observer Variation; D049268:Positron-Emission Tomography / Q000379:methods*; D012372:ROC Curve; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D019788:Fluorodeoxyglucose F18