title: Limited accuracy of DCE-MRI in identification of pathological complete responders after chemoradiotherapy treatment for rectal cancer.
abstract: OBJECTIVE
  To examine whether post-chemoradiotherapy (CRT) DCE-MRI can identify rectal cancer patients with pathologic complete response (pCR).
  
  
  METHODS
  From a rectal cancer surgery database 2007-2014, 61 consecutive patients that met the following inclusion criteria were selected for analysis: (1) stage II/III primary rectal adenocarcinoma; (2) received CRT; (3) underwent surgery (4); underwent rectal DCE-MRI on a 1.5-T MRI scanner. Two experienced radiologists, in consensus, drew regions of interest (ROI) on the sagittal DCE-MRI image in the tumour bed. These were exported from ImageJ to in-house Matlab code for modelling using the Tofts model. Ktrans, Kepand vevalues were compared to pathological response.
  
  
  RESULTS
  Of the 61 initial patients, 37 had data considered adequate for fitting to obtain perfusion parameters. Among the 13 men and 24 women, median age 53 years, there were 8 pCR (22 %). Ktranscould not distinguish patients with pCR. For patients with 90 % or greater response, mean Ktransand Kepvalues were statistically significant (p = 0.032 and 0.027, respectively). Using a cutoff value of Ktrans= 0.25 min-1, the AUC was 0.71.
  
  
  CONCLUSIONS
  Ktranscould be used to identify patients with 90 % or more response to chemoradiotherapy for rectal cancer with an AUC of 0.7.
  
  
  CONCLUSIONS
  • Chemoradiotherapy for rectal cancer causes decreased blood flow and permeability in the tumour bed. • Lower values of blood flow and permeability correlate with good tumour response. • Ktransof 0.25min-1best identifies patients with ≥90 % response with AUC 0.71.
authors.affiliation: Department of Radiology, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, New York, NY, 10065, USA. gollubm@mskcc.org.
authors.forename: Marc J
authors.initials: MJ
authors.lastname: Gollub
authors.affiliation: Department of Radiology, Fudan University Medical Center, Shanghai, China.
authors.forename: Tong
authors.initials: T
authors.lastname: Tong
authors.affiliation: Department of Surgery, Divison of Colorectal Surgery, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, New York, NY, 10065, USA.
authors.forename: Martin
authors.initials: M
authors.lastname: Weiser
authors.affiliation: Department of Epidemiology and Biostatistics, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, New York, NY, 10065, USA.
authors.forename: Junting
authors.initials: J
authors.lastname: Zheng
authors.affiliation: Department of Epidemiology and Biostatistics, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, New York, NY, 10065, USA.
authors.forename: Mithat
authors.initials: M
authors.lastname: Gonen
authors.affiliation: Department of Medical Physics, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, New York, NY, 10065, USA.
authors.forename: Kristen L
authors.initials: KL
authors.lastname: Zakian
mesh_terms: D000230:Adenocarcinoma / Q000000981:diagnostic imaging* / Q000473:pathology / Q000628:therapy*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D059248:Chemoradiotherapy / Q000379:methods; D003287:Contrast Media; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D020360:Neoadjuvant Therapy / Q000379:methods; D009367:Neoplasm Staging; D010477:Perfusion; D011379:Prognosis; D012004:Rectal Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology / Q000628:therapy*; D012189:Retrospective Studies; D016896:Treatment Outcome
chemical_list: D003287:Contrast Media
keywords: Chemoradiotherapy; Complete response; DCE-MRI; Ktrans; Rectal cancer