title: Toward the guidance of transbronchial biopsy: identifying pulmonary nodules with optical coherence tomography.
abstract: BACKGROUND
  Solitary pulmonary nodules (SPNs) frequently require transbronchial needle aspiration (TBNA) or biopsy to determine malignant potential, but have variable diagnostic yields. Confirming needle placement within SPNs during TBNA could significantly increase diagnostic yield. Optical coherence tomography (OCT) provides nondestructive, high-resolution, microstructural imaging with potential to distinguish SPN from parenchyma. We have developed needle-based OCT probes compatible with TBNA. Before OCT can play any significant role in guiding clinical TBNA, OCT interpretation criteria for differentiating SPN from lung parenchyma must be developed and validated.
  
  
  METHODS
  OCT of SPN and parenchyma was performed on 111 ex vivo resection specimens. OCT criteria for parenchyma and SPN were developed and validated in a blinded assessment. Six blinded readers (two pulmonologists, two pathologists, and two OCT experts) were trained on imaging criteria in a 15-min training session prior to interpreting the validation data set.
  
  
  RESULTS
  OCT of lung parenchyma displayed evenly spaced signal-void alveolar spaces, signal-intense backreflections at tissue-air interfaces, or both. SPNs lacked both of these imaging features. Independent validation of OCT criteria by the six blinded readers demonstrated sensitivity and specificity of 95.4% and 98.2%, respectively.
  
  
  CONCLUSIONS
  We have developed and validated OCT criteria for lung parenchyma and SPN with sensitivity and specificity &gt; 95% in this ex vivo study. We anticipate that OCT could be a useful complementary imaging modality to confirm needle placement during TBNA to potentially increase diagnostic yield.
authors.affiliation: Departments of Pathology, Massachusetts General Hospital, Boston, MA; Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, MA; Harvard Medical School, Boston, MA.
authors.forename: Lida P
authors.initials: LP
authors.lastname: Hariri
authors.affiliation: Departments of Pathology, Massachusetts General Hospital, Boston, MA; Harvard Medical School, Boston, MA.
authors.forename: Mari
authors.initials: M
authors.lastname: Mino-Kenudson
authors.affiliation: Pulmonary and Critical Care Unit, Massachusetts General Hospital, Boston, MA; Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, MA.
authors.forename: Matthew B
authors.initials: MB
authors.lastname: Applegate
authors.affiliation: Departments of Pathology, Massachusetts General Hospital, Boston, MA; Harvard Medical School, Boston, MA.
authors.forename: Eugene J
authors.initials: EJ
authors.lastname: Mark
authors.affiliation: Departments of Pathology, Massachusetts General Hospital, Boston, MA; Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, MA; Harvard Medical School, Boston, MA; Harvard-MIT Division of Health Sciences and Technology, Boston, MA.
authors.forename: Guillermo J
authors.initials: GJ
authors.lastname: Tearney
authors.affiliation: Department of Thoracic Surgery, Massachusetts General Hospital, Boston, MA; Harvard Medical School, Boston, MA.
authors.forename: Michael
authors.initials: M
authors.lastname: Lanuti
authors.affiliation: Pulmonary and Critical Care Unit, Massachusetts General Hospital, Boston, MA; Harvard Medical School, Boston, MA.
authors.forename: Colleen L
authors.initials: CL
authors.lastname: Channick
authors.affiliation: Pulmonary and Critical Care Unit, Massachusetts General Hospital, Boston, MA; Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, MA.
authors.forename: Alex
authors.initials: A
authors.lastname: Chee
authors.affiliation: Pulmonary and Critical Care Unit, Massachusetts General Hospital, Boston, MA; Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, MA; Harvard Medical School, Boston, MA. Electronic address: msuter@partners.org.
authors.forename: Melissa J
authors.initials: MJ
authors.lastname: Suter
mesh_terms: D001707:Biopsy, Needle / Q000379:methods; D001980:Bronchi; D006801:Humans; D061705:Image-Guided Biopsy; D003074:Solitary Pulmonary Nodule / Q000473:pathology*; D041623:Tomography, Optical Coherence