title: Lung segment geometry study: simulation of largest possible tumours that fit into bronchopulmonary segments.
abstract: BACKGROUND
  Segmental resection in stage I non-small cell lung cancer (NSCLC) has been well described and is considered to have similar survival rates as lobectomy but with increased rates of local tumour recurrence due to inadequate parenchymal margins. In consequence, today segmentectomy is only performed when the tumour is smaller than 2 cm.
  
  
  METHODS
  Three-dimensional reconstructions from 11 thin-slice CT scans of bronchopulmonary segments were generated, and virtual spherical tumours were placed over the segments, respecting all segmental borders. As a next step, virtual parenchymal safety margins of 2 cm and 3 cm were subtracted and the size of the remaining tumour calculated.
  
  
  RESULTS
  The maximum tumour diameters with a 30-mm parenchymal safety margin ranged from 26.1 mm in right-sided segments 7 + 8 to 59.8 mm in the left apical segments 1-3.
  
  
  CONCLUSIONS
  Using a three-dimensional reconstruction of lung CT scans, we demonstrated that segmentectomy or resection of segmental groups should be feasible with adequate margins, even for larger tumours in selected cases.
authors.affiliation: Department of Thoracic Surgery, Ruhrlandklinik, Essen, Germany. stefan.welter@ruhrlandklinik.uk-essen.de
authors.forename: S
authors.initials: S
authors.lastname: Welter
authors.forename: C
authors.initials: C
authors.lastname: Stöcker
authors.forename: V
authors.initials: V
authors.lastname: Dicken
authors.forename: H
authors.initials: H
authors.lastname: Kühl
authors.forename: S
authors.initials: S
authors.lastname: Krass
authors.forename: G
authors.initials: G
authors.lastname: Stamatis
mesh_terms: D001980:Bronchi / Q000473:pathology / Q000601:surgery*; D002289:Carcinoma, Non-Small-Cell Lung / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery*; D003198:Computer Simulation; D006801:Humans; D008175:Lung Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery*; D009364:Neoplasm Recurrence, Local / Q000517:prevention & control*; D009367:Neoplasm Staging; D018365:Neoplasm, Residual; D018579:Patient Selection; D011013:Pneumonectomy; D011237:Predictive Value of Tests; D011857:Radiographic Image Interpretation, Computer-Assisted; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome; D047368:Tumor Burden