title: Quantitative assessment of background parenchymal enhancement in breast MRI predicts response to risk-reducing salpingo-oophorectomy: preliminary evaluation in a cohort of BRCA1/2 mutation carriers.
abstract: BACKGROUND
  We present a fully automated method for deriving quantitative measures of background parenchymal enhancement (BPE) from breast dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and perform a preliminary evaluation of these measures to assess the effect of risk-reducing salpingo-oophorectomy (RRSO) in a cohort of breast cancer susceptibility gene 1/2 (BRCA1/2) mutation carriers.
  
  
  METHODS
  Breast DCE-MRI data from 50 BRCA1/2 carriers were retrospectively analyzed in compliance with the Health Insurance Portability and Accountability Act and with institutional review board approval. Both the absolute (| |) and relative (%) measures of BPE and fibroglandular tissue (FGT) were computed from the MRI scans acquired before and after RRSO. These pre-RRSO and post-RRSO measures were compared using paired Student's t test. The area under the curve (AUC) of the receiver operating characteristic (ROC) was used to evaluate the performance of relative changes in the BPE and FGT measures in predicting breast cancer that developed in these women after the RRSO surgery.
  
  
  RESULTS
  For the 44 women who did not develop breast cancer after RRSO, the absolute volume of BPE and FGT had a significant decrease (P < 0.05) post-RRSO, whereas for the 6 women who developed breast cancer, there were no significant changes in these measures. Higher values in all BPE and FGT measures were also observed post-RRSO for the women who developed breast cancer, compared with women who did not. Relative changes in BPE percentage were most predictive of women who developed breast cancer after RRSO (P < 0.05), whereas combining BPE percentage and |FGT| yielded an AUC of 0.80, higher than BPE percentage (AUC = 0.78) or |FGT| (AUC = 0.66) alone (both P > 0.02).
  
  
  CONCLUSIONS
  Quantitative measures of BPE and FGT are different before and after RRSO, and their relative changes are associated with prediction of developing breast cancer, potentially indicative of women who are more susceptible to develop breast cancer after RRSO in BRCA1/2 mutation carriers.
authors.affiliation: Department of Radiology, Hospital of the University of Pennsylvania, 1 Silverstein Building, 3400 Spruce Street, Philadelphia, PA, 19104, USA. wus3@upmc.edu.|Present address: Imaging Research Division, Department of Radiology, University of Pittsburgh, 3362 Fifth Avenue, Pittsburgh, PA, 15213, USA. wus3@upmc.edu.
authors.forename: Shandong
authors.initials: S
authors.lastname: Wu
authors.affiliation: Department of Radiology, Hospital of the University of Pennsylvania, 1 Silverstein Building, 3400 Spruce Street, Philadelphia, PA, 19104, USA. susan.weinstein@uphs.upenn.edu.
authors.forename: Susan P
authors.initials: SP
authors.lastname: Weinstein
authors.affiliation: Department of Radiology, Hospital of the University of Pennsylvania, 1 Silverstein Building, 3400 Spruce Street, Philadelphia, PA, 19104, USA. michael.deleo@uphs.upenn.edu.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: DeLeo
authors.affiliation: Department of Radiology, Hospital of the University of Pennsylvania, 1 Silverstein Building, 3400 Spruce Street, Philadelphia, PA, 19104, USA. emily.conant@uphs.upenn.edu.
authors.forename: Emily F
authors.initials: EF
authors.lastname: Conant
authors.affiliation: Department of Biostatistics and Epidemiology, Perelman School of Medicine, University of Pennsylvania, 203 Blockley Hall, 423 Guardian Drive, Philadelphia, PA, USA. jinboche@mail.med.upenn.edu.
authors.forename: Jinbo
authors.initials: J
authors.lastname: Chen
authors.affiliation: Department of Medicine, Hospital of the University of Pennsylvania, 3400 Civic Center Boulevard, 3 West Pavilion, Philadelphia, PA, 19104, USA. susan.domchek@uphs.upenn.edu.
authors.forename: Susan M
authors.initials: SM
authors.lastname: Domchek
authors.affiliation: Department of Radiology, Hospital of the University of Pennsylvania, 1 Silverstein Building, 3400 Spruce Street, Philadelphia, PA, 19104, USA. despina.kontos@uphs.upenn.edu.
authors.forename: Despina
authors.initials: D
authors.lastname: Kontos
mesh_terms: D000328:Adult; D000368:Aged; D019540:Area Under Curve; D001943:Breast Neoplasms / Q000175:diagnosis / Q000209:etiology* / Q000473:pathology* / Q000601:surgery; D015331:Cohort Studies; D005260:Female; D019398:Genes, BRCA1; D024522:Genes, BRCA2; D006579:Heterozygote; D006801:Humans; D007089:Image Enhancement; D008279:Magnetic Resonance Imaging; D008875:Middle Aged; D015233:Models, Statistical; D009154:Mutation; D010052:Ovariectomy; D012372:ROC Curve; D012189:Retrospective Studies; D018570:Risk Assessment; D012489:Salpingostomy