title: Prospective trial of breast MRI versus 2D and 3D ultrasound for evaluation of response to neoadjuvant chemotherapy.
abstract: BACKGROUND
  Preoperative imaging to assess response to neoadjuvant chemotherapy in breast cancer is routine but no single imaging modality is standard of practice. Our hypothesis is that ultrasound (US) is comparable to magnetic resonance imaging (MRI) in the prediction of residual disease.
  
  
  METHODS
  A single-institution, Institutional Review Board-approved prospective trial of primary invasive ductal breast cancer patients receiving neoadjuvant chemotherapy enrolled women from 2008 to 2012. Two-dimensional (2D) and three-dimensional (3D) US, as well as MRI images of pre- and post-neoadjuvant tumors were obtained. Skin involvement or inadequate images were excluded. Residual tumor on imaging was compared with surgical pathology. Differences of tumor volume on imaging and pathology were compared using the non-parametric Wilcoxon signed-rank test. US to MRI agreement was determined by the kappa coefficient. Tumor volumes in estrogen receptor (ER), progesterone receptor (PR), and Her2neu subgroups were compared using the Kruskal-Wallis test. ER/PR staining <5 % was considered negative; Her2neu status was determined by in situ hybridization.
  
  
  RESULTS
  Forty-two patients were enrolled in the study; 39 had evaluable post-treatment data. Four patients were Her2neu positive, and 17 (46 %) patients had triple-negative tumors. Among 11 (28 %) patients with pathologic complete response (pCR), US correctly predicted pCR in six (54.5 %) patients compared with eight (72.7 %) patients when MRI was used. This is a substantial agreement between US and MRI in predicting pCR (kappa = 0.62). There was no difference between 2D and 3D US modalities. For the 39 patients, US and MRI had no significant difference in volume estimation of pathology, even stratified by receptor status.
  
  
  CONCLUSIONS
  The estimation of residual breast tumor volume by US and MRI achieves similar results, including prediction of pCR.
authors.affiliation: Comprehensive Breast Program, H. Lee Moffitt Cancer Center and Research Institute, 12902 Magnolia Drive, Tampa, FL, 33612, USA, marie.lee@moffitt.org.
authors.forename: Marie Catherine
authors.initials: MC
authors.lastname: Lee
authors.forename: Segundo Jaime
authors.initials: SJ
authors.lastname: Gonzalez
authors.forename: Huiyi
authors.initials: H
authors.lastname: Lin
authors.forename: Xiuhua
authors.initials: X
authors.lastname: Zhao
authors.forename: John V
authors.initials: JV
authors.lastname: Kiluk
authors.forename: Christine
authors.initials: C
authors.lastname: Laronga
authors.forename: Blaise
authors.initials: B
authors.lastname: Mooney
mesh_terms: D000328:Adult; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D001943:Breast Neoplasms / Q000000981:diagnostic imaging* / Q000188:drug therapy / Q000378:metabolism / Q000473:pathology*; D017024:Chemotherapy, Adjuvant; D005240:Feasibility Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008875:Middle Aged; D020360:Neoadjuvant Therapy; D009367:Neoplasm Staging; D011379:Prognosis; D011446:Prospective Studies; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism; D011960:Receptors, Estrogen / Q000378:metabolism; D011980:Receptors, Progesterone / Q000378:metabolism; D047368:Tumor Burden; D016217:Ultrasonography, Mammary; D055815:Young Adult
chemical_list: D018719:Erb-b2 Receptor Tyrosine Kinases; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone; C508053:ERBB2 protein, human