Lung cancer screening with low-dose computed tomography: Canadian experience.
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.
Roberts
Heidi C
HC
Department of Medical Imaging, University Health Network, Toronto, ON. Heidi.Roberts@uhn.on.ca
Patsios
Demetris
D
Paul
Narinder S
NS
McGregor
Maureen
M
Weisbrod
Gordon
G
Chung
Taebong
T
Herman
Steven
S
Boerner
Scott
S
Waddell
Thomas
T
Keshavjee
Shafique
S
Darling
Gail
G
Pereira
Andre
A
Kale
Ashwini
A
Bayanati
Hamid
H
Sitartchouk
Igor
I
Tsao
Ming
M
Shepherd
Frances A
FA
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