title: Restaging patients with N2 (stage IIIa) non-small cell lung cancer after neoadjuvant chemoradiotherapy: a prospective study.
abstract: BACKGROUND
  The accuracy of restaging in patients with stage IIIa non-small cell lung cancer after neoadjuvant chemoradiotherapy is unknown.
  
  
  METHODS
  A prospective trial of patients with biopsy-proven N2 disease who underwent initial clinical staging with mediastinoscopy, integrated positron emission tomography/computed tomography (PET/CT), and CT. Patients then were clinically restaged by the same imaging techniques 4 to 12 weeks after their induction chemoradiation therapy and then underwent definitive pathologic staging.
  
  
  RESULTS
  Ninety-three patients had their lymph nodes pathologically restaged. Repeat PET/CT after neoadjuvant therapy missed residual N2 disease in 13/65 (20%) patients and falsely suggested it in 7 of 28 (25%). It was more accurate than repeat CT for restaging at all pathologic stages (stage 0, 92% vs 39%, P = .03; and stage I 89% vs 36%, P = .04). When the maximum standardized uptake value of the primary tumor is decreased by 75% or more, it is highly likely (likelihood ratio, +LR, 6.1) the patient is a complete responder; when it decreased by 55% or more, it is highly likely (+LR, 9.1) the patient is a partial responder. When the maximum standardized uptake value of the N2 node initially involved with metastatic cancer is decreased by more than 50%, it is highly likely (+LR, 7.9) the node is now benign.
  
  
  CONCLUSIONS
  Repeat integrated PET/CT is superior to repeat CT for the restaging of patients with stage IIIa non-small cell lung cancer. The percent decrease in the maximum standardized uptake value of the primary and of the involved lymph node is predictive of pathology; however, nodal biopsies are required since a persistently high maximum standardized uptake value does not equate to residual cancer.
authors.affiliation: Division of Thoracic Surgery, University of Alabama at Birmingham, and Department of Surgery, Birmingham Veterans Administration Hospital, Birmingham, Ala 35294, USA. Robert.cerfolio@ccc.uab.edu
authors.forename: Robert James
authors.initials: RJ
authors.lastname: Cerfolio
authors.forename: Ayesha S
authors.initials: AS
authors.lastname: Bryant
authors.forename: Buddhiwardhan
authors.initials: B
authors.lastname: Ojha
mesh_terms: D000328:Adult; D000368:Aged; D000465:Algorithms; D002289:Carcinoma, Non-Small-Cell Lung / Q000175:diagnosis / Q000473:pathology* / Q000628:therapy*; D017024:Chemotherapy, Adjuvant; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000175:diagnosis / Q000473:pathology* / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D049268:Positron-Emission Tomography; D011446:Prospective Studies; D018714:Radiotherapy, Adjuvant; D015203:Reproducibility of Results; D014057:Tomography, X-Ray Computed