title: Dual-time-point F-18 FDG PET/CT for evaluation of intrathoracic lymph nodes in patients with non-small cell lung cancer.
abstract: OBJECTIVE
  The aim of this study was to evaluate the diagnostic capacity of F-18 fluorodeoxyglucose dual-time-point (DTP) positron emission tomography (PET)/computed tomography (CT) for intrathoracic lymph node (LN) metastases in patients with nonsmall cell lung cancer (NSCLC).
  
  
  METHODS
  Thirty-four patients had DTP PET/CT, with 60 minutes and 2-hour scans (n=19, NSCLC; n=15, benign pulmonary disease). LN diagnoses were confirmed by surgery or clinical follow-up (n=14, metastatic LNs; n=45, nonmetastatic LNs; n=39, inflammatory LNs).
  
  
  RESULTS
  The maximum standardized uptake value (SUVmax) in the metastatic group was significantly higher than those in the nonmetastatic and inflammatory groups on both early- and delayed-phase imaging (each P<0.0001). The retention index (RI) of SUVmax (RI-SUVmax) in the metastatic group was significantly higher than in the nonmetastatic (P=0.0008) and inflammatory groups (P=0.0074). No significant difference was found between SUVmax values of the nonmetastatic and inflammatory groups on early- (P=0.6461) or delayed-phase (P=0.6913), or between RI-SUVmax values of the nonmetastatic and inflammatory groups (P=0.5717). For early-phase SUVmax, the cut-off value for highest accuracy with metastatic LNs was 3.61, yielding a sensitivity of 86.67% and a specificity of 88.00%. For delayed-phase SUVmax, the cut-off value was 4.00, yielding a sensitivity of 91.6% and specificity of 92.9%. For RI-SUVmax, the cut-off value was 20.91%, yielding a sensitivity of 73.6% and specificity of 75.9%.
  
  
  CONCLUSIONS
  DTP PET/CT with a semiquantitative technique may improve diagnostic capacity for nodal staging of NSCLC.
authors.affiliation: PET-RI center, Okayama Kyokuto Hospital, Okayama, Japan. midnight-2007@kyokuto.or.jp
authors.forename: Takayoshi
authors.initials: T
authors.lastname: Shinya
authors.forename: Kammei
authors.initials: K
authors.lastname: Rai
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Okumura
authors.forename: Keiichi
authors.initials: K
authors.lastname: Fujiwara
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Matsuo
authors.forename: Toshiro
authors.initials: T
authors.lastname: Yonei
authors.forename: Toshio
authors.initials: T
authors.lastname: Sato
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Watanabe
authors.forename: Haruyuki
authors.initials: H
authors.lastname: Kawai
authors.forename: Shuhei
authors.initials: S
authors.lastname: Sato
authors.forename: Susumu
authors.initials: S
authors.lastname: Kanazawa
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002289:Carcinoma, Non-Small-Cell Lung / Q000175:diagnosis* / Q000000981:diagnostic imaging; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008175:Lung Neoplasms / Q000175:diagnosis* / Q000000981:diagnostic imaging; D008198:Lymph Nodes / Q000473:pathology; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009362:Neoplasm Metastasis; D049268:Positron-Emission Tomography / Q000379:methods*; D019275:Radiopharmaceuticals; D015203:Reproducibility of Results
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18