title: Semiquantitative and quantitative dynamic contrast-enhanced magnetic resonance imaging measurements predict radiation response in cervix cancer.
abstract: OBJECTIVE
  To evaluate semiquantitative and quantitative dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) measurements in predicting the response to radiotherapy in cervix cancer.
  
  
  METHODS
  Patients with cervix cancer treated radically with chemoradiotherapy had DCE-MRI at three time points: before starting treatment, after 2 weeks of radiotherapy, and in the 5th week of radiotherapy. Semiquantitative measurements obtained from the signal intensity vs. time plots included arrival time of contrast, the slope and maximum slope of contrast uptake, time for peak enhancement, and the contrast enhancement ratio (CER). Pharmacokinetic modeling with a modeled vascular input function was used for the quantitative measurements volume transfer constant (K(trans)), rate constant (k(ep)), fraction plasma volume (fPV), and the initial area under gadolinium-time curve. The correlation of these measurements at each of the three time points with radiologic tumor response was investigated.
  
  
  RESULTS
  Thirteen patients had a total of 38 scans. There was no correlation between the DCE-MRI measurements and the corresponding tumor volumes. A statistically significant correlation with percentage tumor regression was shown with the pretreatment DCE-MRI semiquantitative parameters of peak time (p = 0.046), slope (p = 0.025), maximum slope (p = 0.046), and CER (p = 0.025) and the quantitative parameters K(trans) (p = 0.043) and k(ep) (p = 0.022). Second and third scan measurements did not show any correlation.
  
  
  CONCLUSIONS
  This is the first study to show that pretreatment DCE-MRI quantitative parameters predict the radiation response in cervix cancer. These measurements may allow a more meaningful comparison of DCE-MRI studies from different centers.
authors.affiliation: Edinburgh Cancer Centre, Western General Hospital, Edinburgh, United Kingdom. zahramark@doctors.org.uk
authors.forename: Mark A
authors.initials: MA
authors.lastname: Zahra
authors.forename: Li Tee
authors.initials: LT
authors.lastname: Tan
authors.forename: Andrew N
authors.initials: AN
authors.lastname: Priest
authors.forename: Martin J
authors.initials: MJ
authors.lastname: Graves
authors.forename: Mark
authors.initials: M
authors.lastname: Arends
authors.forename: Robin A F
authors.initials: RA
authors.lastname: Crawford
authors.forename: James D
authors.initials: JD
authors.lastname: Brenton
authors.forename: David J
authors.initials: DJ
authors.lastname: Lomas
authors.forename: Evis
authors.initials: E
authors.lastname: Sala
mesh_terms: D000230:Adenocarcinoma / Q000188:drug therapy / Q000473:pathology / Q000532:radiotherapy*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000970:Antineoplastic Agents / Q000008:administration & dosage; D002294:Carcinoma, Squamous Cell / Q000188:drug therapy / Q000473:pathology / Q000532:radiotherapy*; D002945:Cisplatin / Q000008:administration & dosage; D003287:Contrast Media; D005260:Female; D005682:Gadolinium; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008875:Middle Aged; D011838:Radiation-Sensitizing Agents / Q000008:administration & dosage; D011879:Radiotherapy Dosage; D002583:Uterine Cervical Neoplasms / Q000188:drug therapy / Q000473:pathology / Q000532:radiotherapy*; D055815:Young Adult
chemical_list: D000970:Antineoplastic Agents; D003287:Contrast Media; D011838:Radiation-Sensitizing Agents; D005682:Gadolinium; D002945:Cisplatin