title: Interbronchoscopist variability in endobronchial path selection: a simulation study.
abstract: BACKGROUND
  Endobronchial path selection is important for the bronchoscopic diagnosis of focal lung lesions. Path selection typically involves mentally reconstructing a three-dimensional path by interpreting a stack of two-dimensional (2D) axial plane CT scan sections. The hypotheses of our study about path selection were as follows: (1) bronchoscopists are inaccurate and overly confident when making endobronchial path selections based on 2D CT scan analysis; and (2) path selection accuracy and confidence improve and become better aligned when bronchoscopists employ path-planning methods based on virtual bronchoscopy (VB).
  
  
  METHODS
  Studies of endobronchial path selection comparing three path-planning methods (ie, the standard 2D CT scan analysis and two new VB-based techniques) were performed. The task was to navigate to discrete lesions located between the third-order and fifth-order bronchi of the right upper and middle lobes. Outcome measures were the cumulative accuracy of making four sequential path selection decisions and self-reported confidence (1, least confident; 5, most confident). Both experienced and inexperienced bronchoscopists participated in the studies.
  
  
  RESULTS
  In the first study involving a static paper-based tool, the mean (+/- SD) cumulative accuracy was 14 +/- 3% using 2D CT scan analysis (confidence, 3.4 +/- 1.3) and 49 +/- 15% using a VB-based technique (confidence, 4.2 +/- 1.1; p = 0.0001 across all comparisons). For a second study using an interactive computer-based tool, the mean accuracy was 40 +/- 28% using 2D CT scan analysis (confidence, 3.0 +/- 0.3) and 96 +/- 3% using a dynamic VB-based technique (confidence, 4.6 +/- 0.2). Regardless of the experience level of the bronchoscopist, use of the standard 2D CT scan analysis resulted in poor path selection accuracy and misaligned confidence. Use of the VB-based techniques resulted in considerably higher accuracy and better aligned decision confidence.
  
  
  CONCLUSIONS
  Endobronchial path selection is a source of error in the bronchoscopy workflow. The use of VB-based path-planning techniques significantly improves path selection accuracy over use of the standard 2D CT scan section analysis in this simulation format.
authors.affiliation: Department of Medicine, College of Medicine Penn State University, Hershey, PA 17033, USA.
authors.forename: Marina Y
authors.initials: MY
authors.lastname: Dolina
authors.forename: Duane C
authors.initials: DC
authors.lastname: Cornish
authors.forename: Scott A
authors.initials: SA
authors.lastname: Merritt
authors.forename: Lav
authors.initials: L
authors.lastname: Rai
authors.forename: Rickhesvar
authors.initials: R
authors.lastname: Mahraj
authors.forename: William E
authors.initials: WE
authors.lastname: Higgins
authors.forename: Rebecca
authors.initials: R
authors.lastname: Bascom
mesh_terms: D001980:Bronchi / Q000473:pathology*; D001995:Bronchography; D001999:Bronchoscopy / Q000379:methods*; D003198:Computer Simulation; D006801:Humans; D021621:Imaging, Three-Dimensional; D008175:Lung Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology; D015588:Observer Variation; D012984:Software; D014057:Tomography, X-Ray Computed; D014584:User-Computer Interface