title: Histogram analysis of apparent diffusion coefficients after neoadjuvant chemotherapy in breast cancer.
abstract: OBJECTIVE
  To evaluate the changes in the apparent diffusion coefficient (ADC) histogram during neoadjuvant chemotherapy (NAC) for breast cancer, and to compare the observed changes in pathologically verified responders and non-responders.
  
  
  METHODS
  Sixty-two patients received NAC followed by surgery. Responders were defined by a tumor cell reduction of at least 30 % using the Miller-Payne grading system. All the patients underwent 3T magnetic resonance with diffusion-weighted imaging (b values of 0 and 750 s/mm2) before the NAC and after the completion of two cycles of NAC.
  
  
  RESULTS
  Mean, minimum, 10th, 25th, 50th, and 75th percentile of ADCs significantly increased after NAC and maximum ADC significantly decreased. Skewness became less positive and kurtosis decreased. A tendential, although not statistically significant, higher increase in mean, minimum, 10th, 25th, 50th, 75th, and 90th percentiles of ADCs was observed in responders in comparison with non-responders.
  
  
  CONCLUSIONS
  ADC histogram analysis quantitatively demonstrates the alterations during the treatment course.
authors: Department of Radiology, National Cancer Center, Goyang, Republic of Korea.
authors: Yun Ju
authors: YJ
authors: Kim
authors: Department of Radiology, College of Medicine, Seoul St. Mary's Hospital, The Catholic University of Korea, Seoul, Republic of Korea. rad-ksh@catholic.ac.kr.
authors: Sung Hun
authors: SH
authors: Kim
authors: Department of Hospital Pathology, College of Medicine, Seoul St. Mary's Hospital, The Catholic University of Korea, Seoul, Republic of Korea.
authors: Ah Won
authors: AW
authors: Lee
authors: Department of Hospital Pathology, College of Medicine, Seoul St. Mary's Hospital, The Catholic University of Korea, Seoul, Republic of Korea.
authors: Min-Sun
authors: MS
authors: Jin
authors: Department of Radiology, College of Medicine, Seoul St. Mary's Hospital, The Catholic University of Korea, Seoul, Republic of Korea.
authors: Bong Joo
authors: BJ
authors: Kang
authors: Department of General Surgery, College of Medicine, Seoul St. Mary's Hospital, The Catholic University of Korea, Seoul, Republic of Korea.
authors: Byung Joo
authors: BJ
authors: Song
mesh_terms: D000328:Adult; D000368:Aged; D000970:Antineoplastic Agents / Q000627:therapeutic use*; D001943:Breast Neoplasms / Q000000981:diagnostic imaging* / Q000188:drug therapy* / Q000601:surgery; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D008875:Middle Aged; D020360:Neoadjuvant Therapy; D009367:Neoplasm Staging; D012189:Retrospective Studies; D016896:Treatment Outcome
chemical_list: D000970:Antineoplastic Agents
keywords: Breast neoplasms; Diffusion; Magnetic resonance imaging; Neoadjuvant therapy