title: Background parenchymal enhancement in breast MRI before and after neoadjuvant chemotherapy: correlation with tumour response.
abstract: OBJECTIVE
  To correlate the decrease in background parenchymal enhancement (BPE) and tumour response measured with MRI in breast cancer patients treated with neoadjuvant chemotherapy (NAC).
  
  
  METHODS
  One hundred and forty-six MRI examinations of 73 patients with 80 biopsy-proven breast cancers who underwent breast MRI before and after NAC were retrospectively analysed. All images were reviewed by two blinded readers, who classified BPE into categories (BEC; 1 = minimal, 2 = mild, 3 = moderate, 4 = marked) before and after NAC. Histopathological and morphological tumour responses were analysed and compared.
  
  
  RESULTS
  The distribution of BEC 1/2/3/4 was 25/46/18/11 % before and 78/20/2/0 % after NAC. On average, BPE decreased by 0.87 BEC. Cohen's kappa showed substantial agreement (k = 0.73-0.77) before and moderate agreement (k = 0.43-0.60) after NAC and moderate agreement (k = 0.62-0.60) concerning the change in BEC. Correlating the change in BPE with tumour response, the average decrease in BEC was 1.3 in cases of complete remission, 0.83 in cases with partial response, 0.85 in cases with stable disease and 0.40 in cases with progressive disease. Correlation analysis showed a significant correlation between the decrease in BEC and tumour response (r = -0.24, p = 0.03).
  
  
  CONCLUSIONS
  BPE decreased by, on average, 0.87 BEC following NAC for breast cancer. The degree of BPE reduction seemed to correlate with tumour response.
  
  
  CONCLUSIONS
  • BPE decreases by an average of 0.87 categories under neoadjuvant chemotherapy. • The reduction of BPE following neoadjuvant chemotherapy correlates with the tumour response. • The classification of the BPE shows good agreement among trained readers.
authors.affiliation: Diagnostic and Interventional Radiology, University Hospital Tuebingen, Hoppe-Seyler-Str. 3, 72076, Tuebingen, Germany. heike.preibsch@med.uni-tuebingen.de.
authors.forename: H
authors.initials: H
authors.lastname: Preibsch
authors.affiliation: Diagnostic and Interventional Radiology, University Hospital Tuebingen, Hoppe-Seyler-Str. 3, 72076, Tuebingen, Germany.
authors.forename: L
authors.initials: L
authors.lastname: Wanner
authors.affiliation: Diagnostic and Interventional Radiology, University Hospital Tuebingen, Hoppe-Seyler-Str. 3, 72076, Tuebingen, Germany.
authors.forename: S D
authors.initials: SD
authors.lastname: Bahrs
authors.affiliation: Diagnostic and Interventional Radiology, University Hospital Tuebingen, Hoppe-Seyler-Str. 3, 72076, Tuebingen, Germany.
authors.forename: B M
authors.initials: BM
authors.lastname: Wietek
authors.affiliation: Diagnostic Center for Breast Cancer and Screening Mammography Brandenburg Ost, Koepenicker Straße 29, 15711, Koenigs Wusterhausen, Germany.
authors.forename: K C
authors.initials: KC
authors.lastname: Siegmann-Luz
authors.affiliation: Department of Gynecology and Obstetrics, University Hospital Tuebingen, Calwerstr. 7, 72076, Tuebingen, Germany.
authors.forename: E
authors.initials: E
authors.lastname: Oberlecher
authors.affiliation: Department of Gynecology and Obstetrics, University Hospital Tuebingen, Calwerstr. 7, 72076, Tuebingen, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Hahn
authors.affiliation: Institute of Pathology and Neuropathology, University Hospital Tuebingen, Liebermeisterstr. 8, 72076, Tuebingen, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Staebler
authors.affiliation: Diagnostic and Interventional Radiology, University Hospital Tuebingen, Hoppe-Seyler-Str. 3, 72076, Tuebingen, Germany.
authors.forename: K
authors.initials: K
authors.lastname: Nikolaou
authors.affiliation: Diagnostic and Interventional Radiology, University Hospital Tuebingen, Hoppe-Seyler-Str. 3, 72076, Tuebingen, Germany.
authors.forename: B
authors.initials: B
authors.lastname: Wiesinger
mesh_terms: D000328:Adult; D000368:Aged; D000970:Antineoplastic Agents / Q000627:therapeutic use; D001940:Breast / Q000000981:diagnostic imaging*; D001943:Breast Neoplasms / Q000000981:diagnostic imaging* / Q000188:drug therapy; D018270:Carcinoma, Ductal, Breast / Q000000981:diagnostic imaging* / Q000188:drug therapy; D018275:Carcinoma, Lobular / Q000000981:diagnostic imaging* / Q000188:drug therapy; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008875:Middle Aged; D020360:Neoadjuvant Therapy; D011379:Prognosis; D012189:Retrospective Studies
chemical_list: D000970:Antineoplastic Agents
keywords: Background enhancement; Breast MRI; Breast cancer; Chemotherapy; Tumour response