title: Can perfusion MRI predict response to preoperative treatment in rectal cancer?
abstract: OBJECTIVE
  Dynamic contrast-enhanced MRI (DCE-MRI) provides information on perfusion and could identify good prognostic tumors. Aim of this study was to evaluate whether DCE-MRI using a novel blood pool contrast-agent can accurately predict the response to neoadjuvant chemoradiotherapy in locally advanced rectal cancer.
  
  
  METHODS
  Thirty patients underwent DCE-MRI before and 7-10weeks after chemoradiotherapy. Regions of interest were drawn on DCE-MRI with T2W-images as reference. DCE-MRI-based kinetic parameters (initial slope, initial peak, late slope, and AUC at 60, 90, and 120s) determined pre- and post-CRT and their Δ were compared between good (TRG1-2) and poor (TRG3-5) responders. Optimal thresholds were determined and sensitivities, specificities, positive predictive values (PPV), and negative predictive values (NPV) were calculated.
  
  
  RESULTS
  Pre-therapy, the late slope was able to discriminate between good and poor responders (-0.05×10(-3) vs. 0.62×10(-3), p<0.001) with an AUC of 0.90, sensitivity 92%, specificity 82%, PPV 80%, and NPV 93%. Other pre-CRT parameters showed no significant differences, nor any post-CRT parameters or their Δ.
  
  
  CONCLUSIONS
  The kinetic parameter 'late slope' derived from DCE-MRI could potentially be helpful to predict before the onset of neoadjuvant chemoradiotherapy which tumors are likely going to respond. This could allow for personalized treatment-options in rectal cancer patients.
authors.affiliation: Department of Radiology, Maastricht University Medical Center, The Netherlands; Department of Surgery, Maastricht University Medical Center, The Netherlands; GROW - School for Oncology and Developmental Biology, Maastricht University Medical Center, The Netherlands. Electronic address: mh.martens@hotmail.com.
authors.forename: Milou H
authors.initials: MH
authors.lastname: Martens
authors.affiliation: Department of Radiology, Maastricht University Medical Center, The Netherlands.
authors.forename: Samina
authors.initials: S
authors.lastname: Subhani
authors.affiliation: Department of Radiology, Maastricht University Medical Center, The Netherlands; Department of Surgery, Maastricht University Medical Center, The Netherlands; GROW - School for Oncology and Developmental Biology, Maastricht University Medical Center, The Netherlands.
authors.forename: Luc A
authors.initials: LA
authors.lastname: Heijnen
authors.affiliation: Department of Radiology, Maastricht University Medical Center, The Netherlands.
authors.forename: Doenja M J
authors.initials: DM
authors.lastname: Lambregts
authors.affiliation: GROW - School for Oncology and Developmental Biology, Maastricht University Medical Center, The Netherlands; Department of Radiation Oncology, Maastro Clinic, The Netherlands.
authors.forename: Jeroen
authors.initials: J
authors.lastname: Buijsen
authors.affiliation: Department of Radiology, Maastricht University Medical Center, The Netherlands.
authors.forename: Monique
authors.initials: M
authors.lastname: Maas
authors.affiliation: Department of Pathology, Maastricht University Medical Center, The Netherlands.
authors.forename: Robert G
authors.initials: RG
authors.lastname: Riedl
authors.affiliation: Department of Radiology, Maastricht University Medical Center, The Netherlands.
authors.forename: Cecile R L P N
authors.initials: CR
authors.lastname: Jeukens
authors.affiliation: Department of Surgery, Maastricht University Medical Center, The Netherlands.
authors.forename: Geerard L
authors.initials: GL
authors.lastname: Beets
authors.affiliation: Department of Radiology, Maastricht University Medical Center, The Netherlands.
authors.forename: Ewelina
authors.initials: E
authors.lastname: Kluza
authors.affiliation: Department of Radiology, Maastricht University Medical Center, The Netherlands; GROW - School for Oncology and Developmental Biology, Maastricht University Medical Center, The Netherlands.
authors.forename: Regina G H
authors.initials: RG
authors.lastname: Beets-Tan
mesh_terms: D000368:Aged; D059186:Chemoradiotherapy, Adjuvant; D003287:Contrast Media; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D020360:Neoadjuvant Therapy; D011300:Preoperative Care; D011379:Prognosis; D011446:Prospective Studies; D012004:Rectal Neoplasms / Q000175:diagnosis* / Q000473:pathology / Q000628:therapy*; D012680:Sensitivity and Specificity; D016896:Treatment Outcome
chemical_list: D003287:Contrast Media
keywords: Neoadjuvant chemoradiation; Preoperative treatment; Rectal cancer; Response prediction