title: MRI phenotype of breast cancer: Kinetic assessment for molecular subtypes.
abstract: OBJECTIVE
  To evaluate the dynamic contrast-enhanced magnetic resonance imaging (MRI) kinetic characteristics of newly diagnosed breast cancer molecular subtypes.
  
  
  METHODS
  Breast MRI examinations of 112 patients with newly diagnosed breast cancer were reviewed. Cases of newly diagnosed invasive ductal carcinoma were sorted by molecular subtype (28 TN, 11 HER2 +, 73 Lum A/B) and MRI field strength, with lesion segmentation and kinetic analyses performed on a dedicated workstation. For kinetic assessment, 50% and 100% thresholds were employed for display of medium and rapid uptake. Kinetic profiles in terms of percent volume for six kinetic types (medium-persistent, medium-plateau, medium-washout, fast-persistent, fast-plateau, fast-washout) relative to the whole volume of the lesion were obtained. Statistical analysis of the kinetic profiles was performed using Welch's t-test.
  
  
  RESULTS
  Percent volume of HER2-positive lesions with >100% uptake at early phase on 3T strength MRI exams was significantly greater compared with luminal A/B (93.8 ± 0.92 vs. 77.3 ± 7.2; P < 0.01) and triple negative (93.8 ± 0.92 vs. 81.3 ± 8.2; P < 0.05) subtypes. The >50% early phase uptake for HER2+ lesions was also higher than Lum A/B (99.1 ± 0.73 vs. 93.6 ± 3.05; P < 0.01) at 3T. In the 1.5T subgroup the percent volume of HER2+ tumors with >50% and >100% early phase uptake trended higher than Lum A/B lesions without reaching significance.
  
  
  CONCLUSIONS
  The percent volume of HER2-positive tumors demonstrating rapid early contrast uptake is significantly increased compared to other molecular subtypes.
authors.affiliation: University of Chicago Medicine, Radiology, Chicago, Illinois, USA.
authors.forename: Eric
authors.initials: E
authors.lastname: Blaschke
authors.affiliation: University of Chicago Medicine, Radiology, Chicago, Illinois, USA.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Abe
mesh_terms: D000328:Adult; D000368:Aged; D001943:Breast Neoplasms / Q000378:metabolism* / Q000473:pathology*; D018270:Carcinoma, Ductal, Breast / Q000378:metabolism / Q000473:pathology*; D003198:Computer Simulation; D003287:Contrast Media / Q000493:pharmacokinetics; D005260:Female; D019786:Gadolinium DTPA / Q000493:pharmacokinetics*; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D007700:Kinetics; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008657:Metabolic Clearance Rate; D008875:Middle Aged; D008954:Models, Biological; D010641:Phenotype; D057285:Precision Medicine / Q000379:methods; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D055815:Young Adult
chemical_list: D003287:Contrast Media; D019786:Gadolinium DTPA; D018719:Erb-b2 Receptor Tyrosine Kinases; C064925:gadodiamide
keywords: HER2; breast cancer; dynamic contrast MRI; luminal A/B; triple negative