title: Diagnostic value of EBUS-TBNA for lung cancer with non-enlarged lymph nodes: a study in a tuberculosis-endemic country.
abstract: BACKGROUND
  In tuberculosis (TB)-endemic areas, contrast-enhanced computed tomography (CT) and positron emission tomography (PET) findings of lung cancer patients with non-enlarged lymph nodes are frequently discrepant. Endobronchial ultrasound-guided transbronchial aspiration (EBUS-TBNA) enables real-time nodal sampling, and thereby improves nodal diagnosis accuracy. This study aimed to compare the accuracy of nodal diagnosis by using EBUS-TBNA, and PET.
  
  
  METHODS
  We studied 43 lung cancer patients with CT-defined non-enlarged mediastinal and hilar lymph nodes and examined 78 lymph nodes using EBUS-TBNA.
  
  
  RESULTS
  The sensitivity, specificity, positive predictive value, and negative predictive value of EBUS-TBNA were 80.6%, 100%, 100%, and 85.7%, respectively. PET had low specificity (18.9%) and a low positive predictive value (44.4%). The diagnostic accuracy of EBUS-TBNA was higher than that of PET (91% vs. 47.4%; p<0.001). Compared to CT-based nodal assessment, PET yielded a positive diagnostic impact in 36.9% nodes, a negative diagnostic impact in 46.2% nodes, and no diagnostic impact in 16.9% nodes. Patients with lymph nodes showing negative PET diagnostic impact had a high incidence of previous pulmonary TB. Multivariate analysis indicated that detection of hilar nodes on PET was an independent predictor of negative diagnostic impact of PET.
  
  
  CONCLUSIONS
  In a TB-endemic area with a condition of CT-defined non-enlarged lymph node, the negative diagnostic impact of PET limits its clinical usefulness for nodal staging; therefore, EBUS-TBNA, which facilitates direct diagnosis, is preferred.
authors.affiliation: Department of Thoracic Medicine, Chang Gung Memorial Hospital, Chang Gung University School of Medicine, Taipei, Taiwan.
authors.forename: Chih-Hsi
authors.initials: CH
authors.lastname: Kuo
authors.forename: Hao-Cheng
authors.initials: HC
authors.lastname: Chen
authors.forename: Fu-Tsai
authors.initials: FT
authors.lastname: Chung
authors.forename: Yu-Lun
authors.initials: YL
authors.lastname: Lo
authors.forename: Kang-Yun
authors.initials: KY
authors.lastname: Lee
authors.forename: Chih-Wei
authors.initials: CW
authors.lastname: Wang
authors.forename: Wen-Han
authors.initials: WH
authors.lastname: Kuo
authors.forename: Tzu-Chen
authors.initials: TC
authors.lastname: Yen
authors.forename: Han-Pin
authors.initials: HP
authors.lastname: Kuo
mesh_terms: D000230:Adenocarcinoma / Q000150:complications / Q000000981:diagnostic imaging / Q000473:pathology*; D000368:Aged; D044963:Biopsy, Fine-Needle / Q000379:methods; D001999:Bronchoscopy / Q000379:methods; D003937:Diagnosis, Differential; D019353:Endemic Diseases; D019160:Endosonography / Q000379:methods*; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000150:complications / Q000000981:diagnostic imaging / Q000473:pathology*; D008198:Lymph Nodes / Q000473:pathology; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging / Q000379:methods*; D009929:Organ Size; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity; D014397:Tuberculosis, Pulmonary / Q000150:complications / Q000000981:diagnostic imaging / Q000453:epidemiology*