title: Background parenchymal signal enhancement ratio at preoperative MR imaging: association with subsequent local recurrence in patients with ductal carcinoma in situ after breast conservation surgery.
abstract: OBJECTIVE
  To retrospectively investigate whether the background parenchymal features around a tumor at preoperative dynamic contrast material-enhanced magnetic resonance (MR) imaging are associated with ipsilateral breast tumor recurrence (IBTR)-free survival in patients with ductal carcinoma in situ (DCIS) after breast conservation surgery.
  
  
  METHODS
  The institutional review board approved this study, and the requirement for informed consent was waived. Between 2004 and 2009, 215 consecutive women with pure DCIS who had undergone preoperative dynamic contrast-enhanced MR imaging and curative breast conservation surgery were identified. Clinical-pathologic features (age, menopausal status, presentation of clinical findings, biopsy method, tumor size, nuclear grade, hormonal receptor status, margin status, and adjuvant therapy) and MR imaging features (lesion size, background parenchymal enhancement grade, fibroglandular density, parenchymal signal enhancement ratio [SER] around the tumor, lesion type, and lesion kinetics) were analyzed. A Cox proportional hazards model was used to determine the association between MR imaging variables and IBTR-free survival after controlling for clinical-pathologic variables. Reproducibility of SER measurements was evaluated by using the intraclass correlation coefficient.
  
  
  RESULTS
  There were 15 of 215 (7.0%) IBTR cases (nine DCIS cases and six invasive cases) at a median of 36 months (range, 11-61 months). Multivariate analysis showed that higher parenchymal SER (hazard ratio [HR] = 2.028, P < .001 for reader 1; HR = 1.652, P < .001 for reader 2) and larger histologic tumor size (HR = 1.360, P = .009 for reader 1; HR = 1.402, P = .006 for reader 2) were independent factors associated with worse IBTR-free survival. The intraclass correlation coefficient of SER measurements between two readers was 0.852 (95% confidence interval: 0.811, 0.885).
  
  
  CONCLUSIONS
  Higher parenchymal SER around the tumor at preoperative dynamic contrast-enhanced MR imaging and larger histologic tumor size were independent factors associated with worse IBTR-free survival in patients with DCIS after breast conservation surgery.
authors.affiliation: From the Department of Radiology, Seoul National University College of Medicine, Seoul National University Hospital, 101 Daehak-ro, Jongno-gu, Seoul 110-744, Republic of Korea.
authors.forename: Sun-Ah
authors.initials: SA
authors.lastname: Kim
authors.forename: Nariya
authors.initials: N
authors.lastname: Cho
authors.forename: Eun Bi
authors.initials: EB
authors.lastname: Ryu
authors.forename: Mirinae
authors.initials: M
authors.lastname: Seo
authors.forename: Min Sun
authors.initials: MS
authors.lastname: Bae
authors.forename: Jung Min
authors.initials: JM
authors.lastname: Chang
authors.forename: Woo Kyung
authors.initials: WK
authors.lastname: Moon
mesh_terms: D000328:Adult; D000368:Aged; D001706:Biopsy; D001943:Breast Neoplasms / Q000473:pathology / Q000601:surgery*; D002278:Carcinoma in Situ / Q000175:diagnosis*; D002285:Carcinoma, Intraductal, Noninfiltrating / Q000473:pathology / Q000601:surgery*; D003287:Contrast Media; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D015412:Mastectomy, Segmental; D008536:Meglumine / Q000031:analogs & derivatives; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000175:diagnosis*; D009942:Organometallic Compounds; D012189:Retrospective Studies; D016019:Survival Analysis
chemical_list: D003287:Contrast Media; D009942:Organometallic Compounds; C064572:gadobenic acid; D008536:Meglumine