title: Lung cancer screening with low-dose computed tomography: Canadian experience.
abstract: BACKGROUND
  In 2003, the Department of Medical Imaging at the University Health Network in Toronto, Ontario, became the first Canadian site of the Intemational Early Lung Cancer Action Program (I-ELCAP). We report the results from the first 1000 baseline studies.
  
  
  METHODS
  Between June 2003 and December 2005, we enrolled 1000 high-risk smokers (that is, smokers with a history of at least 10 pack years, or the equivalent of one pack daily for 10 years), aged 55 years or older. A low-dose helical computed tomography (CT) (40 to 60 mA, 120 kV) was performed with 1.0 mm to 1.25 mm collimation. Nodules found at baseline were followed according to the I-ELCAP protocol: (1) no noncalcified nodules (NCNs) or NCNs < or =4 mm or nonsolid nodules < 8 mm, annual repeat; (2) NCNs > or =5 mm or nonsolid nodules > or =8 mm, 3-month follow-up; or (3) nonsolid nodules > or =15 mm, antibiotics and 1-month follow-up.
  
  
  RESULTS
  The first 1000 study participants were aged 63 years, standard deviation (SD) 6 years, with a smoking history of 38 pack years, SD 22 pack years; 662 (66%) were former smokers, and 338 (34%) were current smokers; 453 (45%) were men, and 547 (55%) were women. Of the participants, 256 (26%) had a positive baseline low-dose computed tomography (LDCT) scan; 227 (23%) were followed after 3 months and 16 (1.6%) after 1 month; 7 (0.7%) received a contrast-enhanced CT and 6 (0.6%) an immediate CT-guided biopsy. Twenty-six invasive procedures were performed: 22 CT-guided biopsies, 1 ultrasound-guided lymph node metastasis biopsy, 1 bronchoscopic biopsy, and 2 surgeries. The malignancy rate of the invasive procedures was 85%. Overall, the malignancy prevalence is 2.2%. Of the malignancies, 20 are lung carcinomas: 19 non-small-cell lung carcinomas (NSCLCs) (14 adenocarcinoma or bronchioalveolar carcinoma [BAC], 4 squamous carcinoma, and 1 large-cell carcinoma) and 1 small-cell carcinoma; 15 (78%) of the NSCLCs are Stage I. Fourteen patients underwent surgery (1 pneumonectomy, 9 lobectomies, and 4 segmentectomies).
  
  
  CONCLUSIONS
  Our results confirm that LDCT identifies small, early-stage, resectable lung cancer in a high-risk population.
authors.affiliation: Department of Medical Imaging, University Health Network, Toronto, ON. Heidi.Roberts@uhn.on.ca
authors.forename: Heidi C
authors.initials: HC
authors.lastname: Roberts
authors.forename: Demetris
authors.initials: D
authors.lastname: Patsios
authors.forename: Narinder S
authors.initials: NS
authors.lastname: Paul
authors.forename: Maureen
authors.initials: M
authors.lastname: McGregor
authors.forename: Gordon
authors.initials: G
authors.lastname: Weisbrod
authors.forename: Taebong
authors.initials: T
authors.lastname: Chung
authors.forename: Steven
authors.initials: S
authors.lastname: Herman
authors.forename: Scott
authors.initials: S
authors.lastname: Boerner
authors.forename: Thomas
authors.initials: T
authors.lastname: Waddell
authors.forename: Shafique
authors.initials: S
authors.lastname: Keshavjee
authors.forename: Gail
authors.initials: G
authors.lastname: Darling
authors.forename: Andre
authors.initials: A
authors.lastname: Pereira
authors.forename: Ashwini
authors.initials: A
authors.lastname: Kale
authors.forename: Hamid
authors.initials: H
authors.lastname: Bayanati
authors.forename: Igor
authors.initials: I
authors.lastname: Sitartchouk
authors.forename: Ming
authors.initials: M
authors.lastname: Tsao
authors.forename: Frances A
authors.initials: FA
authors.lastname: Shepherd
mesh_terms: D000230:Adenocarcinoma / Q000000981:diagnostic imaging; D002282:Adenocarcinoma, Bronchiolo-Alveolar / Q000000981:diagnostic imaging; D000368:Aged; D001706:Biopsy / Q000379:methods; D001999:Bronchoscopy; D002170:Canada; D002277:Carcinoma / Q000000981:diagnostic imaging; D002289:Carcinoma, Non-Small-Cell Lung / Q000000981:diagnostic imaging; D002294:Carcinoma, Squamous Cell / Q000000981:diagnostic imaging; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008175:Lung Neoplasms / Q000000981:diagnostic imaging*; D008207:Lymphatic Metastasis / Q000473:pathology; D008297:Male; D008403:Mass Screening / Q000379:methods*; D008875:Middle Aged; D009367:Neoplasm Staging; D011013:Pneumonectomy; D011829:Radiation Dosage; D015641:Radiography, Interventional; D012189:Retrospective Studies; D012907:Smoking; D036542:Tomography, Spiral Computed / Q000379:methods*; D018084:Ultrasonography, Interventional