title: Comparison of digital mammography alone and digital mammography plus tomosynthesis in a population-based screening program.
abstract: OBJECTIVE
  To assess cancer detection rates, false-positive rates before arbitration, positive predictive values for women recalled after arbitration, and the type of cancers detected with use of digital mammography alone and combined with tomosynthesis in a large prospective screening trial.
  
  
  METHODS
  A prospective, reader- and modality-balanced screening study of participants undergoing combined mammography plus tomosynthesis, the results of which were read independently by four different radiologists, is under way. The study was approved by a regional ethics committee, and all participants provided written informed consent. The authors performed a preplanned interim analysis of results from 12,631 examinations interpreted by using mammography alone and mammography plus tomosynthesis from November 22, 2010, to December 31, 2011. Analyses were based on marginal log-linear models for binary data, accounting for correlated interpretations and adjusting for reader-specific performance levels by using a two-sided significance level of .0294.
  
  
  RESULTS
  Detection rates, including those for invasive and in situ cancers, were 6.1 per 1000 examinations for mammography alone and 8.0 per 1000 examinations for mammography plus tomosynthesis (27% increase, adjusted for reader; P = .001). False-positive rates before arbitration were 61.1 per 1000 examinations with mammography alone and 53.1 per 1000 examinations with mammography plus tomosynthesis (15% decrease, adjusted for reader; P < .001). After arbitration, positive predictive values for recalled patients with cancers verified later were comparable (29.1% and 28.5%, respectively, with mammography alone and mammography plus tomosynthesis; P = .72). Twenty-five additional invasive cancers were detected with mammography plus tomosynthesis (40% increase, adjusted for reader; P < .001). The mean interpretation time was 45 seconds for mammography alone and 91 seconds for mammography plus tomosynthesis (P < .001).
  
  
  CONCLUSIONS
  The use of mammography plus tomosynthesis in a screening environment resulted in a significantly higher cancer detection rate and enabled the detection of more invasive cancers. Clinical trial registration no. NCT01248546.
authors.affiliation: Department of Radiology, Breast Imaging Center, Oslo University Hospital Ullevaal, University of Oslo, Kirkeveien 166, N-0407 Oslo, Norway. perska@ous-hf.no
authors.forename: Per
authors.initials: P
authors.lastname: Skaane
authors.forename: Andriy I
authors.initials: AI
authors.lastname: Bandos
authors.forename: Randi
authors.initials: R
authors.lastname: Gullien
authors.forename: Ellen B
authors.initials: EB
authors.lastname: Eben
authors.forename: Ulrika
authors.initials: U
authors.lastname: Ekseth
authors.forename: Unni
authors.initials: U
authors.lastname: Haakenaasen
authors.forename: Mina
authors.initials: M
authors.lastname: Izadi
authors.forename: Ingvild N
authors.initials: IN
authors.lastname: Jebsen
authors.forename: Gunnar
authors.initials: G
authors.lastname: Jahr
authors.forename: Mona
authors.initials: M
authors.lastname: Krager
authors.forename: Loren T
authors.initials: LT
authors.lastname: Niklason
authors.forename: Solveig
authors.initials: S
authors.lastname: Hofvind
authors.forename: David
authors.initials: D
authors.lastname: Gur
mesh_terms: D000368:Aged; D001943:Breast Neoplasms / Q000000981:diagnostic imaging* / Q000453:epidemiology; D005189:False Positive Reactions; D005260:Female; D006801:Humans; D016015:Logistic Models; D008327:Mammography / Q000379:methods*; D008403:Mass Screening; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D009664:Norway / Q000453:epidemiology; D011237:Predictive Value of Tests; D011446:Prospective Studies; D011829:Radiation Dosage; D011857:Radiographic Image Interpretation, Computer-Assisted; D012042:Registries; D014057:Tomography, X-Ray Computed / Q000379:methods*