title: Screening for early lung cancer with low-dose spiral CT: prevalence in 817 asymptomatic smokers.
abstract: OBJECTIVE
  To present prevalence screening data from a nonrandomized screening trial by using low-dose computed tomography (CT) and a simple algorithm based on the size and attenuation of detected nodules to guide diagnostic work-up.
  
  
  METHODS
  Eight hundred seventeen asymptomatic volunteers (age range, 40-78 years; median age, 53 years; median tobacco consumption, 45 pack-years) underwent spiral low-dose CT of the chest without contrast material enhancement. We regarded all noncalcified pulmonary nodules greater than 10 mm in diameter as potentially malignant and recommended histologic examination or follow-up after 3, 6, 12, and 24 months to exclude growth. For noncalcified pulmonary nodules of 10 mm or smaller, repeat low-dose CT was recommended to exclude growth.
  
  
  RESULTS
  In 43% (350 of 817) of individuals, 858 noncalcified pulmonary nodules were found. Thirty-two nodules in 29 subjects were larger than 10 mm. Biopsy of 15 lesions revealed lung cancer in 12 lesions in 11 subjects (prevalence for all ages, 1.3% [11 of 817 subjects]; >50 years of age, 2.1% [11 of 519 subjects]; >60 years of age, 3.9% [eight of 206 subjects]), with a high proportion of early tumor stages (seven tumors, stage I; two, stage II; and three, stage III); three lesions were benign. In 17 nodules larger than 10 mm, follow-up with low-dose CT for a minimum of 24 months did not demonstrate growth.
  
  
  CONCLUSIONS
  Lung cancer screening with low-dose CT demonstrated a prevalence of asymptomatic cancers in 1.3% of a smoking population, including a high proportion of early tumor stages and a 20% (three of 15) rate of invasive procedures for benign lesions.
authors.affiliation: Department of Clinical Radiology, University of Münster, Albert-Schweitzer-Strasse 33, D-48129 Münster, Germany. diestef@uni-muenster.de
authors.forename: Stefan
authors.initials: S
authors.lastname: Diederich
authors.forename: Dag
authors.initials: D
authors.lastname: Wormanns
authors.forename: Michael
authors.initials: M
authors.lastname: Semik
authors.forename: Michael
authors.initials: M
authors.lastname: Thomas
authors.forename: Horst
authors.initials: H
authors.lastname: Lenzen
authors.forename: Nikolaus
authors.initials: N
authors.lastname: Roos
authors.forename: Walter
authors.initials: W
authors.lastname: Heindel
mesh_terms: D000328:Adult; D000368:Aged; D002114:Calcinosis / Q000000981:diagnostic imaging; D005260:Female; D006801:Humans; D008168:Lung / Q000000981:diagnostic imaging; D008175:Lung Neoplasms / Q000000981:diagnostic imaging* / Q000453:epidemiology / Q000209:etiology; D008297:Male; D008403:Mass Screening; D008875:Middle Aged; D015995:Prevalence; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects*; D014057:Tomography, X-Ray Computed / Q000379:methods