title: Diffusion-weighted magnetic resonance imaging for the prediction of pathologic response to neoadjuvant chemoradiotherapy in esophageal cancer.
abstract: OBJECTIVE
  To explore the value of diffusion-weighted magnetic resonance imaging (DW-MRI) for the prediction of pathologic response to neoadjuvant chemoradiotherapy (nCRT) in esophageal cancer.
  
  
  METHODS
  In 20 patients receiving nCRT for esophageal cancer DW-MRI scanning was performed before nCRT, after 8-13 fractions, and before surgery. The median tumor apparent diffusion coefficient (ADC) was determined at these three time points. The predictive potential of initial tumor ADC, and change in ADC (ΔADC) during and after treatment for pathologic complete response (pathCR) and good response were assessed. Good response was defined as pathCR or near-pathCR (tumor regression grade [TRG] 1 or 2).
  
  
  RESULTS
  A pathCR after nCRT was found in 4 of 20 patients (20%), and 8 patients (40%) showed a good response to nCRT. The ΔADCduring was significantly higher in pathCR vs. non-pathCR patients (34.6%±10.7% [mean±SD] vs. 14.0%±13.1%, p=0.016), as well as in good vs. poor responders (30.5%±8.3% vs. 9.5%±12.5%, p=0.002). The ΔADCduring was predictive of residual cancer at a threshold of 29% (sensitivity of 100%, specificity of 75%, PPV of 94%, and NPV of 100%), and for poor pathologic response at a threshold of 21% (sensitivity of 82%, specificity of 100%, PPV of 100%, and NPV of 80%).
  
  
  CONCLUSIONS
  In this exploratory study, the treatment-induced change in ADC during the first 2-3weeks of nCRT for esophageal cancer seemed highly predictive of histopathologic response. Larger series are warranted to verify these results.
authors.affiliation: Department of Radiotherapy, University Medical Center Utrecht, The Netherlands; Department of Surgery, University Medical Center Utrecht, The Netherlands. Electronic address: P.S.N.vanRossum-2@umcutrecht.nl.
authors.forename: Peter S N
authors.initials: PS
authors.lastname: van Rossum
authors.affiliation: Department of Radiotherapy, University Medical Center Utrecht, The Netherlands.
authors.forename: Astrid L H M W
authors.initials: AL
authors.lastname: van Lier
authors.affiliation: Department of Radiotherapy, University Medical Center Utrecht, The Netherlands.
authors.forename: Marco
authors.initials: M
authors.lastname: van Vulpen
authors.affiliation: Department of Radiotherapy, University Medical Center Utrecht, The Netherlands.
authors.forename: Onne
authors.initials: O
authors.lastname: Reerink
authors.affiliation: Department of Radiotherapy, University Medical Center Utrecht, The Netherlands.
authors.forename: Jan J W
authors.initials: JJ
authors.lastname: Lagendijk
authors.affiliation: Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, United States.
authors.forename: Steven H
authors.initials: SH
authors.lastname: Lin
authors.affiliation: Department of Surgery, University Medical Center Utrecht, The Netherlands.
authors.forename: Richard
authors.initials: R
authors.lastname: van Hillegersberg
authors.affiliation: Department of Surgery, University Medical Center Utrecht, The Netherlands.
authors.forename: Jelle P
authors.initials: JP
authors.lastname: Ruurda
authors.affiliation: Department of Radiotherapy, University Medical Center Utrecht, The Netherlands. Electronic address: G.J.Meijer@umcutrecht.nl.
authors.forename: Gert J
authors.initials: GJ
authors.lastname: Meijer
authors.affiliation: Department of Radiotherapy, University Medical Center Utrecht, The Netherlands.
authors.forename: Irene M
authors.initials: IM
authors.lastname: Lips
mesh_terms: D000368:Aged; D059248:Chemoradiotherapy; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods; D004938:Esophageal Neoplasms / Q000473:pathology* / Q000628:therapy*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D020360:Neoadjuvant Therapy; D016896:Treatment Outcome
keywords: Chemoradiotherapy; Diffusion-weighted MRI; Esophageal cancer; Functional imaging; Neoadjuvant therapy