title: High-resolution diffusion-weighted imaging for monitoring breast cancer treatment response.
abstract: OBJECTIVE
  The aim of this work was to compare a high-resolution diffusion-weighted imaging (HR-DWI) acquisition (voxel size = 4.8 mm(3)) to a standard diffusion-weighted imaging (STD-DWI) acquisition (voxel size = 29.3 mm(3)) for monitoring neoadjuvant therapy-induced changes in breast tumors.
  
  
  METHODS
  Nine women with locally advanced breast cancer were imaged with both HR-DWI and STD-DWI before and after 3 weeks (early treatment) of neoadjuvant taxane-based treatment. Tumor apparent diffusion coefficient (ADC) metrics (mean and histogram percentiles) from both DWI methods were calculated, and their relationship to tumor volume change after 12 weeks of treatment (posttreatment) measured by dynamic contrast enhanced magnetic resonance imaging was evaluated with a Spearman's rank correlation.
  
  
  RESULTS
  The HR-DWI pretreatment 15th percentile tumor ADC (P = .03) and early treatment 15th, 25th, and 50th percentile tumor ADCs (P = .008, .010, .04, respectively) were significantly lower than the corresponding STD-DWI percentile ADCs. The mean tumor HR-ADC was significantly lower than STD-ADC at the early treatment time point (P = .02), but not at the pretreatment time point (P = .07). A significant early treatment increase in tumor ADC was found with both methods (P < .05). Correlations between HR-DWI tumor ADC and posttreatment tumor volume change were higher than the STD-DWI correlations at both time points and the lower percentile ADCs had the strongest correlations.
  
  
  CONCLUSIONS
  These initial results suggest that the HR-DWI technique has potential for improving characterization of low tumor ADC values over STD-DWI and that HR-DWI may be of value in evaluating tumor change with treatment.
authors.affiliation: Department of Radiology and Biomedical Imaging, University of California, Box 1667, San Francisco, San Francisco, CA 94115, USA. lisa.wilmes@ucsf.edu
authors.forename: Lisa J
authors.initials: LJ
authors.lastname: Wilmes
authors.forename: Rebekah L
authors.initials: RL
authors.lastname: McLaughlin
authors.forename: David C
authors.initials: DC
authors.lastname: Newitt
authors.forename: Lisa
authors.initials: L
authors.lastname: Singer
authors.forename: Sumedha P
authors.initials: SP
authors.lastname: Sinha
authors.forename: Evelyn
authors.initials: E
authors.lastname: Proctor
authors.forename: Dorota J
authors.initials: DJ
authors.lastname: Wisner
authors.forename: Emine U
authors.initials: EU
authors.lastname: Saritas
authors.forename: John
authors.initials: J
authors.lastname: Kornak
authors.forename: Ajit
authors.initials: A
authors.lastname: Shankaranarayanan
authors.forename: Suchandrima
authors.initials: S
authors.lastname: Banerjee
authors.forename: Ella F
authors.initials: EF
authors.lastname: Jones
authors.forename: Bonnie N
authors.initials: BN
authors.lastname: Joe
authors.forename: Nola M
authors.initials: NM
authors.lastname: Hylton
mesh_terms: D000328:Adult; D000368:Aged; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000473:pathology*; D001952:Bridged-Ring Compounds / Q000627:therapeutic use*; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008875:Middle Aged; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D043823:Taxoids / Q000627:therapeutic use*; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D001952:Bridged-Ring Compounds; D043823:Taxoids; C080625:taxane