title: Minimal-dose computed tomography is superior to chest x-ray for the follow-up and treatment of patients with resected lung cancer.
abstract: OBJECTIVE
  A minimal-dose computed tomography scan of the thorax (MnDCT) delivers a radiation dose comparable with a chest x-ray (CXR). We hypothesized that in patients with completely resected lung cancer, surveillance with MnDCT, when compared with CXR, leads to earlier detection and a higher rate of treatment of new or recurrent lung cancer.
  
  
  METHODS
  After lung cancer resection, patients prospectively were enrolled for surveillance with MnDCT and CXR at 3, 6, 12, 18, 24, 36, 48, and 60 months. Images were interpreted by different blinded radiologists. When new or recurrent cancer was suspected, standard-dose CT and/or a tissue biopsy were performed for confirmation.
  
  
  RESULTS
  Between 2007 and 2012, 271 patients were included and 1137 pairs of CXR and MnDCT were analyzed. MnDCT was more sensitive (94% vs 21%; P < .0001) and had a higher negative predictive value (99% vs 96%; P = .007) than CXR for the diagnosis of new or recurrent lung cancer. The prevalence of new or recurrent lung cancer was 23.2% (63 of 271), of whom 78% (49 of 63) had asymptomatic disease. The majority of asymptomatic patients (75%; 37 of 49) were treated with curative intent and had a median survival of 69 months. The remainder of patients received palliative treatment (24%; 12 of 49) and had a median survival of 25 months (P < .0001).
  
  
  CONCLUSIONS
  After curative resection of lung cancer, MnDCT is superior to CXR for the detection of new or recurrent lung cancer. The majority of new or recurrent cancer was detected by MnDCT at an asymptomatic phase, allowing for curative treatment, leading to a long survival.
authors.affiliation: Division of Thoracic Surgery, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Waël C
authors.initials: WC
authors.lastname: Hanna
authors.affiliation: Department of Radiology, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Narinder S
authors.initials: NS
authors.lastname: Paul
authors.affiliation: Division of Thoracic Surgery, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Gail E
authors.initials: GE
authors.lastname: Darling
authors.affiliation: Department of Radiology, University of Toronto, Toronto, Ontario, Canada; Division of Biostatistics, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Hadas
authors.initials: H
authors.lastname: Moshonov
authors.affiliation: Division of Thoracic Surgery, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Frances
authors.initials: F
authors.lastname: Allison
authors.affiliation: Division of Thoracic Surgery, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Thomas K
authors.initials: TK
authors.lastname: Waddell
authors.affiliation: Division of Thoracic Surgery, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Marcelo
authors.initials: M
authors.lastname: Cypel
authors.affiliation: Division of Thoracic Surgery, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Marc E
authors.initials: ME
authors.lastname: de Perrot
authors.affiliation: Division of Thoracic Surgery, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Yasufuku
authors.affiliation: Division of Thoracic Surgery, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Shaf
authors.initials: S
authors.lastname: Keshavjee
authors.affiliation: Division of Thoracic Surgery, University of Toronto, Toronto, Ontario, Canada. Electronic address: andrew.pierre@uhn.ca.
authors.forename: Andrew F
authors.initials: AF
authors.lastname: Pierre
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001706:Biopsy; D055088:Early Detection of Cancer; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D016015:Logistic Models; D008175:Lung Neoplasms / Q000000981:diagnostic imaging* / Q000401:mortality / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009364:Neoplasm Recurrence, Local / Q000000981:diagnostic imaging* / Q000401:mortality / Q000628:therapy; D016609:Neoplasms, Second Primary / Q000000981:diagnostic imaging* / Q000401:mortality / Q000628:therapy; D016017:Odds Ratio; D009864:Ontario / Q000453:epidemiology; D011013:Pneumonectomy; D011237:Predictive Value of Tests; D015995:Prevalence; D011829:Radiation Dosage; D013902:Radiography, Thoracic; D012307:Risk Factors; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome
keywords: 10.2; 10.4; 36.1; CT; CXR; MnDCT; chest x-ray; computed tomography; minimal-dose computed tomography