title: Stereotactic 11-gauge vacuum-assisted breast biopsy: a validation study.
abstract: OBJECTIVE
  The aim of our study was to determine the false-negative rate of stereotactic 11-gauge vacuum-assisted biopsy in a validation study of lesions that had subsequent surgical excision.
  
  
  METHODS
  Retrospective review was performed of 318 lesions that underwent stereotactic 11-gauge vacuum-assisted biopsy and subsequent surgical excision. A false-negative case was defined as a pathologically proven cancer in which stereotactic biopsy yielded benign results without atypia. Medical records, imaging studies, and histologic findings were reviewed.
  
  
  RESULTS
  False-negative findings were encountered at stereotactic 11-gauge vacuum-assisted biopsy in 3.3% (7/214) of pathologically proven cancers. False-negative findings occurred in 3.5% (4/115) of malignant calcification lesions versus 3.0% (3/99) of malignant masses (p = 1.0). The seven false-negative findings included five Breast Imaging Reporting and Data System (BI-RADS) category 5 lesions that yielded benign results at biopsy, one BI-RADS category 4 mass that benign breast tissue, and one BI-RADS category 4 cluster of calcifications in which no calcifications were retrieved. The false-negative rate was 10.0% (6/60) for radiologists who performed 15 or fewer previous stereotactic vacuum-assisted biopsy procedures versus 0.6% (1/154) for radiologists who performed more than 15 previous stereotactic vacuum-assisted biopsy procedures (p = 0.002).
  
  
  CONCLUSIONS
  Stereotactic 11-gauge vacuum-assisted biopsy had a false-negative rate of 3.3% that diminished to 0.6% with experience. All false-negative findings could be prospectively identified because of failure to sample calcifications or imaging-histologic discordance.
authors.affiliation: Department of Radiology, University of Vienna Medical School, AKH Wien, Waehringer Guertel 18-20, A-1090 Vienna, Austria.
authors.forename: Georg
authors.initials: G
authors.lastname: Pfarl
authors.forename: Thomas H
authors.initials: TH
authors.lastname: Helbich
authors.forename: Christopher C
authors.initials: CC
authors.lastname: Riedl
authors.forename: Teresa
authors.initials: T
authors.lastname: Wagner
authors.forename: Michael
authors.initials: M
authors.lastname: Gnant
authors.forename: Margaretha
authors.initials: M
authors.lastname: Rudas
authors.forename: Laura
authors.initials: L
authors.lastname: Liberman
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001707:Biopsy, Needle / Q000295:instrumentation / Q000379:methods*; D001940:Breast / Q000473:pathology*; D001943:Breast Neoplasms / Q000175:diagnosis* / Q000473:pathology; D002114:Calcinosis / Q000473:pathology; D005188:False Negative Reactions; D005260:Female; D006801:Humans; D008875:Middle Aged; D012189:Retrospective Studies; D013238:Stereotaxic Techniques / Q000295:instrumentation