title: Improvement of non-small-cell lung cancer staging by means of positron emission tomography.
abstract: BACKGROUND
  Exact staging of ipsi- and contralateral mediastinal lymph-node metastases (N 1/2 vs. N3) is essential for the therapeutic strategy in non-small-cell lung cancer (NSCLC). CT and mediastinoscopy are the standards of reference for N staging. However, even with these combined measures the extent of invasion of mediastinal lymph nodes can remain vague. 18FDG Positron Emission Tomography (18FDG-PET) has recently been shown to detect invaded nodes with high accuracy. The purpose of this study was to evaluate 18FDG-PET as an aid in N staging.
  
  
  METHODS
  27 patients with suspected NSCLC were clinically staged by means of CT, bronchoscopy, mediastinoscopy, and bone scintigraphy. Additionally, 18FDG-PET was performed preoperatively for analysis of topography of invaded lymph nodes. CT and 18FDG-PET were evaluated in a blinded fashion. Surgical therapy was performed with radical lymphadenectomy. CT N staging as well as PET N staging results were compared with the pathological diagnoses (pTN). Specificity, sensitivity, and accuracy of CT and PET in N staging were calculated.
  
  
  RESULTS
  14 squamous-cell carcinomas, 10 adenocarcinomas, and 3 non-malignant tumors were found. In 8 patients no invasion was found (N0), in 13 patients an ipsilateral invasion (N1/2), and in 3 patients a contralateral invasion (N3). In the correct detection of N1/2 the sensitivity of CT and of PET was 0.77, the specificity of CT and of PET was 0.79. The accuracy of CT was 0.74 and of PET 0.78. By combining CT and PET accuracy was 0.85.
  
  
  CONCLUSIONS
  Adequate preoperative LN staging is possible with both CT and 18FDG-PET. The accuracy, however, can be improved by a combination of CT and 18FDG-PET.
authors.affiliation: Division of Thoracic-, Cardiac- and Vascular Surgery, University of Tübingen, Germany.
authors.forename: J M
authors.initials: JM
authors.lastname: Albes
authors.forename: R
authors.initials: R
authors.lastname: Lietzenmayer
authors.forename: U
authors.initials: U
authors.lastname: Schott
authors.forename: E
authors.initials: E
authors.lastname: Schülen
authors.forename: M
authors.initials: M
authors.lastname: Wehrmann
authors.forename: G
authors.initials: G
authors.lastname: Ziemer
mesh_terms: D000230:Adenocarcinoma / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery; D001999:Bronchoscopy; D002289:Carcinoma, Non-Small-Cell Lung / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery; D002294:Carcinoma, Squamous Cell / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008171:Lung Diseases / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery; D008175:Lung Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery; D008207:Lymphatic Metastasis / Q000000981:diagnostic imaging / Q000473:pathology; D008297:Male; D008481:Mediastinoscopy; D008875:Middle Aged; D009367:Neoplasm Staging / Q000379:methods; D011013:Pneumonectomy; D011446:Prospective Studies; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014055:Tomography, Emission-Computed; D014057:Tomography, X-Ray Computed