title: Diagnostic yield of electromagnetic navigation bronchoscopy is highly dependent on the presence of a Bronchus sign on CT imaging: results from a prospective study.
abstract: BACKGROUND
  Electromagnetic navigation bronchoscopy (ENB) has been developed as a novel ancillary tool for the bronchoscopic diagnosis of pulmonary nodules. Despite successful navigation in 90% of patients, ENB diagnostic yield does not generally exceed 70%. We sought to determine whether the presence of a bronchus sign on CT imaging conditions diagnostic yield of ENB and might account for the discrepancy between successful navigation and diagnostic yield.
  
  
  METHODS
  We conducted a prospective, single-center study of ENB in 51 consecutive patients with pulmonary nodules. ENB was chosen as the least invasive diagnostic technique in patients with a high surgical risk, suspected metastatic disease, or advanced-stage disease, or in those who demanded a preoperative diagnosis prior to undergoing curative resection. We studied patient and technical variables that might condition diagnostic yield, including size, cause, location, distance to the pleural surface, and fluorodeoxyglucose uptake of a given nodule; the presence of a bronchus sign on CT imaging; registration point divergence; and the minimum distance from the tip of the locatable guide to the nodule measured during the procedure.
  
  
  RESULTS
  The diagnostic yield of ENB was 67% (34/51). The sensitivity and specificity of ENB for malignancy in this study were 71% and 100%, respectively. ENB was diagnostic in 79% (30/38) patients with a bronchus sign on CT imaging but only in 4/13 (31%) with no discernible bronchus sign. Univariate analysis identified the bronchus sign (P = .005) and nodule size (P = .04) as statistically significant variables conditioning yield, but on multivariate analysis, only the bronchus sign remained significant (OR, 7.6; 95% CI, 1.8-31.7). No procedure-related complications were observed.
  
  
  CONCLUSIONS
  ENB diagnostic yield is highly dependent on the presence of a bronchus sign on CT imaging.
authors.affiliation: Departamento de Neumología, Clínica Universitaria de Navarra, Pamplona, Spain. lmseijo@unav.es
authors.forename: Luis M
authors.initials: LM
authors.lastname: Seijo
authors.forename: Juan P
authors.initials: JP
authors.lastname: de Torres
authors.forename: María D
authors.initials: MD
authors.lastname: Lozano
authors.forename: Gorka
authors.initials: G
authors.lastname: Bastarrika
authors.forename: Ana B
authors.initials: AB
authors.lastname: Alcaide
authors.forename: Maria M
authors.initials: MM
authors.lastname: Lacunza
authors.forename: Javier J
authors.initials: JJ
authors.lastname: Zulueta
mesh_terms: D000230:Adenocarcinoma / Q000175:diagnosis / Q000000981:diagnostic imaging; D000368:Aged; D000704:Analysis of Variance; D001980:Bronchi / Q000473:pathology*; D001999:Bronchoscopy / Q000379:methods*; D002289:Carcinoma, Non-Small-Cell Lung / Q000175:diagnosis / Q000000981:diagnostic imaging; D002294:Carcinoma, Squamous Cell / Q000175:diagnosis / Q000000981:diagnostic imaging; D016001:Confidence Intervals; D003937:Diagnosis, Differential; D055590:Electromagnetic Phenomena; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000175:diagnosis / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D016017:Odds Ratio; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D003074:Solitary Pulmonary Nodule / Q000175:diagnosis / Q000000981:diagnostic imaging*; D018709:Statistics, Nonparametric; D014057:Tomography, X-Ray Computed / Q000379:methods*