title: [Diffusion-weighted MRI--a new parameter for advanced rectal carcinoma?].
abstract: OBJECTIVE
  To evaluate the predictive value of apparent diffusion coefficient (ADC) on therapy outcome of combined chemoradiation in patients with primary carcinoma of the rectum.
  
  
  METHODS
  Prior to standardized, combined, neoadjuvant chemoradiation, 16 patients with primary carcinoma of the rectum (cT3) were examined with magnetic resonance imaging (MRI). Diffusion-weighted spin echo echo-planar images (SE-EPI) and contrast-enhanced T 1 -weighted spin echo (SE) images at 1.5 Tesla were obtained. The mean ADC of the tumor region was calculated and correlated with the therapy outcome substantiated by postsurgical histopathologic staging.
  
  
  RESULTS
  Tumor down-staging (pT0-2) occurred in 9 patients (therapy responders) and no down-staging (pT3) in 7 patients (therapy non-responders). The mean ADC measured 0.476 +/- 0.114 x 10(-3) mm 2/s in the responder group and 0.703 +/- 0.085 x 10(-3) mm 2/s in the non-responder group. Comparison of the mean ADC between the groups reached statistical significance (p = 0.001).
  
  
  CONCLUSIONS
  The mean ADC might be a new quantitative parameter to predict therapy outcome of combined preoperative chemoradiation in patients with primary carcinoma of the rectum.
authors.affiliation: Universitätsklinik für Strahlentherapie, Leopold-Franzens Universität Innsbruck, Austria. Patrick.A.Hein@hitchcock.org
authors.forename: P A
authors.initials: PA
authors.lastname: Hein
authors.forename: C
authors.initials: C
authors.lastname: Kremser
authors.forename: W
authors.initials: W
authors.lastname: Judmaier
authors.forename: J
authors.initials: J
authors.lastname: Griebel
authors.forename: A
authors.initials: A
authors.lastname: Rudisch
authors.forename: K-P
authors.initials: KP
authors.lastname: Pfeiffer
authors.forename: E B
authors.initials: EB
authors.lastname: Hug
authors.forename: P
authors.initials: P
authors.lastname: Lukas
authors.forename: A F
authors.initials: AF
authors.lastname: DeVries
mesh_terms: D000230:Adenocarcinoma / Q000175:diagnosis* / Q000188:drug therapy / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery; D000328:Adult; D000368:Aged; D017024:Chemotherapy, Adjuvant; D003131:Combined Modality Therapy; D019583:Dose Fractionation, Radiation; D017352:Echo-Planar Imaging; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008875:Middle Aged; D020360:Neoadjuvant Therapy; D011237:Predictive Value of Tests; D011300:Preoperative Care; D011379:Prognosis; D011446:Prospective Studies; D011879:Radiotherapy Dosage; D018714:Radiotherapy, Adjuvant; D012004:Rectal Neoplasms / Q000175:diagnosis* / Q000188:drug therapy / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery; D012007:Rectum / Q000473:pathology; D013997:Time Factors