title: Preoperative intrathoracic lymph node staging in patients with non-small-cell lung cancer: accuracy of integrated positron emission tomography and computed tomography.
abstract: OBJECTIVE
  To evaluate the accuracy of integrated positron emission tomography with 18F-fluoro-2-deoxy-D-glucose (FDG) and computed tomography (PET/CT) in preoperative intrathoracic lymph node staging in patients with non-small-cell lung cancer (NSCLC) and to ascertain the role of invasive staging in verifying positron emission tomography (PET)/computed tomography (CT) results.
  
  
  METHODS
  Retrospective, single institution study of consecutive patients with suspected or pathologically proven, potentially resectable NSCLC undergoing integrated PET/CT scanning in the same PET centre. Lymph node staging was pathologically confirmed on tissue specimens obtained at mediastinoscopy and/or thoracotomy. Statistical evaluation of PET/CT results was performed on a per-patient and per-nodal-station bases.
  
  
  RESULTS
  A total of 1001 nodal stations (723 mediastinal, 148 hilar and 130 intrapulmonary) were evaluated in 159 patients. Nodes were positive for malignancy in 48 (30.2%) out of 159 patients (N1=17; N2=30; N3=1) and 71 (7.1%) out of 1001 nodal stations (N1=24; N2=46; N3=1). At univariate analysis, lymph node involvement was significantly associated (p<0.05) with the following primary tumour characteristics: increasing diameter, maximum standardised uptake value >9, central location and presence of vascular invasion. PET/CT staged the disease correctly in 128 out of 159 patients (80.5%), overstaging occurred in nine patients (5.7%) and understaging in 22 patients (13.8%). The overall sensitivity, specificity, positive and negative predictive values, and accuracy of PET/CT for detecting metastatic lymph nodes were 54.2%, 91.9%, 74.3%, 82.3% and 80.5% on a per-patient basis, and 57.7%, 98.5%, 74.5%, 96.8% and 95.6% on per-nodal-station basis. With regard to N2/N3 disease, PET/CT accuracy was 84.9% and 95.3% on a per-patient basis and on per-nodal-station basis, respectively. Referring to nodal size, PET/CT sensitivity to detect malignant involvement was 32.4% (12/37) in nodes <10mm, and 85.3% (29/34) in nodes > or = 10mm.
  
  
  CONCLUSIONS
  Our data show that integrated PET/CT provides high specificity but low sensitivity and accuracy in intrathoracic nodal staging of NSCLC patients and underscore the continued need for surgical staging.
authors.affiliation: University of Turin, Department of Clinical & Biological Sciences, Thoracic Surgery Unit, Orbassano, Turin, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Billé
authors.forename: Ettore
authors.initials: E
authors.lastname: Pelosi
authors.forename: Andrea
authors.initials: A
authors.lastname: Skanjeti
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Arena
authors.forename: Luca
authors.initials: L
authors.lastname: Errico
authors.forename: Piero
authors.initials: P
authors.lastname: Borasio
authors.forename: Maurizio
authors.initials: M
authors.lastname: Mancini
authors.forename: Francesco
authors.initials: F
authors.lastname: Ardissone
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002289:Carcinoma, Non-Small-Cell Lung / Q000175:diagnosis / Q000473:pathology / Q000556:secondary* / Q000601:surgery; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008175:Lung Neoplasms / Q000175:diagnosis / Q000473:pathology* / Q000601:surgery; D008207:Lymphatic Metastasis; D008297:Male; D008481:Mediastinoscopy; D008875:Middle Aged; D009367:Neoplasm Staging; D049268:Positron-Emission Tomography / Q000379:methods; D019275:Radiopharmaceuticals; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18