title: Occult nodal disease in patients with non-small-cell lung cancer who are suitable for stereotactic ablative body radiation.
abstract: BACKGROUND
  Stereotactic ablative body radiotherapy is a therapeutic option for patients with peripheral stage I NSCLC in whom surgical resection is considered high risk. Patients receiving SABR do not undergo systematic nodal dissection and any occult nodal metastases will therefore go undetected. Our aim was to determine what proportion of cases this might represent.
  
  
  METHODS
  We retrospectively studied patients who underwent lung resections for presumed stage I NSCLC between 2008 and 2011 at a United Kingdom teaching hospital. We reviewed postoperative pathological lymph node staging and analyzed a subset of these patients in whom SABR would have been be technically possible.
  
  
  RESULTS
  We reviewed 128 cases of presumed NSCLC preoperatively staged as T1/2a N0 M0. Of 89 cases with peripheral tumor location, 8 patients (8.9%) had nodal involvement at surgical resection.
  
  
  CONCLUSIONS
  Our data show that approximately 1 in 11 patients with peripheral stage I NSCLC will have occult mediastinal/hilar nodal involvement. Although this is a relatively small proportion, routine use of EBUS-TBNA for nodal staging in patients undergoing SABR might identify a greater proportion of patients with nodal disease compared with a strategy of nodal staging directed according to positron emission tomography-computed tomography findings.
authors.affiliation: Leeds Teaching Hospitals NHS Trust, Leeds, United Kingdom. Electronic address: jonnyrobson@doctors.org.uk.
authors.forename: Jonathan M
authors.initials: JM
authors.lastname: Robson
authors.affiliation: Leeds Teaching Hospitals NHS Trust, Leeds, United Kingdom.
authors.forename: Sriram
authors.initials: S
authors.lastname: Vaidyanathan
authors.affiliation: Leeds Teaching Hospitals NHS Trust, Leeds, United Kingdom.
authors.forename: Leanne
authors.initials: L
authors.lastname: Cheyne
authors.affiliation: Leeds Teaching Hospitals NHS Trust, Leeds, United Kingdom.
authors.forename: Michael
authors.initials: M
authors.lastname: Snee
authors.affiliation: Leeds Teaching Hospitals NHS Trust, Leeds, United Kingdom.
authors.forename: Kevin
authors.initials: K
authors.lastname: Franks
authors.affiliation: Leeds Teaching Hospitals NHS Trust, Leeds, United Kingdom.
authors.forename: Matthew E J
authors.initials: ME
authors.lastname: Callister
mesh_terms: D002289:Carcinoma, Non-Small-Cell Lung / Q000473:pathology* / Q000532:radiotherapy / Q000601:surgery; D015331:Cohort Studies; D006801:Humans; D008175:Lung Neoplasms / Q000473:pathology* / Q000532:radiotherapy / Q000601:surgery; D008197:Lymph Node Excision; D008198:Lymph Nodes / Q000000981:diagnostic imaging / Q000473:pathology*; D008207:Lymphatic Metastasis; D009367:Neoplasm Staging; D011237:Predictive Value of Tests; D016634:Radiosurgery; D015203:Reproducibility of Results; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed; D006113:United Kingdom
keywords: Endobronchial ultrasound; Mediastinal lymph node; Radiotherapy; Staging; Thoracic surgery