title: Pharmacokinetic parameters derived from dynamic contrast enhanced MRI of cervical cancers predict chemoradiotherapy outcome.
abstract: OBJECTIVE
  To assess the prognostic value of pharmacokinetic parameters derived from pre-chemoradiotherapy dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) of cervical cancer patients.
  
  
  METHODS
  Seventy-eight patients with locally advanced cervical cancer underwent DCE-MRI with Gd-DTPA before chemoradiotherapy. The pharmacokinetic Brix and Tofts models were fitted to contrast enhancement curves in all tumor voxels, providing histograms of several pharmacokinetic parameters (Brix: A(Brix), k(ep), k(el), Tofts: K(trans), ν(e)). A percentile screening approach including log-rank survival tests was undertaken to identify the clinically most relevant part of the intratumoral parameter distribution. Clinical endpoints were progression-free survival (PFS) and locoregional control (LRC). Multivariate analysis including FIGO stage and tumor volume was used to assess the prognostic significance of the imaging parameters.
  
  
  RESULTS
  A(Brix), k(el), and K(trans) were significantly (P<0.05) positively associated with both clinical LRC and PFS, while ν(e) was significantly positively correlated with PFS only. k(ep) showed no association with any endpoint. A(Brix) was positively correlated with K(trans) and ν(e), and showed the strongest association with endpoint in the log-rank testing. k(el) and K(trans) were independent prognostic factors in multivariate analysis with LRC as endpoint.
  
  
  CONCLUSIONS
  Parameters estimated by pharmacokinetic analysis of DCE-MR images obtained prior to chemoradiotherapy may be used for identifying patients at risk of treatment failure.
authors: Department of Medical Physics, Oslo University Hospital, Olso, Norway.
authors: Erlend K F
authors: EK
authors: Andersen
authors: Knut Håkon
authors: KH
authors: Hole
authors: Kjersti V
authors: KV
authors: Lund
authors: Kolbein
authors: K
authors: Sundfør
authors: Gunnar B
authors: GB
authors: Kristensen
authors: Heidi
authors: H
authors: Lyng
authors: Eirik
authors: E
authors: Malinen
mesh_terms: D059248:Chemoradiotherapy; D003287:Contrast Media / Q000493:pharmacokinetics*; D005260:Female; D019786:Gadolinium DTPA / Q000493:pharmacokinetics*; D006801:Humans; D007089:Image Enhancement; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008954:Models, Biological; D016016:Proportional Hazards Models; D016896:Treatment Outcome; D002583:Uterine Cervical Neoplasms / Q000401:mortality / Q000473:pathology / Q000628:therapy*
chemical_list: D003287:Contrast Media; D019786:Gadolinium DTPA