title: Inter-reader variability when applying the 2013 Fleischner guidelines for potential solitary subsolid lung nodules.
abstract: BACKGROUND
  In 2013, the Fleischner Society published recommendations for managing subsolid pulmonary nodules. Inter-reader variability has not yet been defined and has potential implications for the ease and reproducibility of applying the guidelines to clinical practice.
  
  
  OBJECTIVE
  To evaluate inter-reader variability when applying the 2013 Fleischner guidelines for potential solitary subsolid lung nodules.
  
  
  METHODS
  Potential nodules were identified through a systematic retrospective review of CT studies that reported a ground-glass lesion. Three radiologists decided whether these lesions fit criteria of a subsolid nodule and thus merit application of the Fleischner Society guidelines, determined if a solid component was present, and measured each component in two dimensions. Final management recommendations were based on these intermediate decisions. Inter-reader variability for management was calculated and Fleiss' kappa was used to determine significance. Logistic regression and Fisher's exact test determined whether management was contingent on each intermediate decision.
  
  
  RESULTS
  Forty-four nodules with mean diameter of 9.4 mm were evaluated by three radiologists. Final management recommendations were in agreement for 93 out of 132 cases (70.4%, kappa = 0.56). Inter-reader variability in management recommendation was contingent on disagreement over whether a pulmonary lesion fit criteria of a subsolid nodule for 24 cases (P < 0.01), whether there was a solid component for 10 cases (P = 0.01), and whether the measurement met the threshold of 5 mm for five cases (P = 0.12).
  
  
  CONCLUSIONS
  There is moderate inter-reader variability when applying the 2013 Fleischner Society management recommendations. Significant contributors of variability include whether the potential lesions fit subsolid nodule criteria and whether a solid component is present. Measurement variability does not significantly affect the final management decisions.
authors.affiliation: Department of Radiology, Santa Clara Valley Medical Center, San Jose, CA, USA alex3005@stanford.edu.
authors.forename: Alex
authors.initials: A
authors.lastname: Penn
authors.affiliation: Department of Radiology, Santa Clara Valley Medical Center, San Jose, CA, USA.
authors.forename: Mingming
authors.initials: M
authors.lastname: Ma
authors.affiliation: Department of Radiology, Santa Clara Valley Medical Center, San Jose, CA, USA.
authors.forename: Benjamin B
authors.initials: BB
authors.lastname: Chou
authors.affiliation: Department of Radiology, Santa Clara Valley Medical Center, San Jose, CA, USA.
authors.forename: Jeffrey R
authors.initials: JR
authors.lastname: Tseng
authors.affiliation: Department of Radiology, Santa Clara Valley Medical Center, San Jose, CA, USA.
authors.forename: Peter
authors.initials: P
authors.lastname: Phan
mesh_terms: D000465:Algorithms; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D017410:Practice Guidelines as Topic; D015203:Reproducibility of Results; D003074:Solitary Pulmonary Nodule / Q000000981:diagnostic imaging*; D014057:Tomography, X-Ray Computed / Q000379:methods*
keywords: CT – spiral; decision analysis; lung; thorax