title: Incremental value of diffusion weighted and dynamic contrast enhanced MRI in the detection of locally recurrent prostate cancer after radiation treatment: preliminary results.
abstract: OBJECTIVE
  To assess the incremental value of diffusion-weighted (DW-MRI) and dynamic contrast-enhanced MRI (DCE-MRI) to T2-weighted MRI (T2WI) in detecting locally recurrent prostate cancer after radiotherapy.
  
  
  METHODS
  Twenty-four patients (median age, 70 years) with a history of radiotherapy-treated prostate cancer underwent multi-parametric MRI (MP-MRI) and transrectal prostate biopsy. Two readers independently scored the likelihood of cancer on a 1-5 scale, using T2WI alone and then adding DW-MRI and DCE-MRI. Areas under receiver operating characteristic curves (AUCs) were estimated at the patient and prostate-side levels. The apparent diffusion coefficient (ADC) from DW-MRI and the K(trans), k(ep), v(e), AUGC90 and AUGC180 from DCE-MRI were recorded.
  
  
  RESULTS
  Biopsy was positive in 16/24 (67%) and negative in 8/24 (33%) patients. AUCs for readers 1 and 2 increased from 0.64 and 0.53 to 0.95 and 0.86 with MP-MRI, at the patient level, and from 0.73 and 0.66 to 0.90 and 0.79 with MP-MRI, at the prostate-side level (p values < 0.05). Biopsy-positive and biopsy-negative prostate sides differed significantly in median ADC [1.44 vs. 1.68 (×10(-3) mm(2)/s)], median K(trans) [1.07 vs. 0.34 (1/min)], and k(ep) [2.06 vs 1.0 (1/min)] (p values < 0.05).
  
  
  CONCLUSIONS
  MP-MRI was significantly more accurate than T2WI alone in detecting locally recurrent prostate cancer after radiotherapy.
authors.affiliation: Department of Radiology, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, NY 10065, USA. akino@mskcc.org
authors.forename: Oguz
authors.initials: O
authors.lastname: Akin
authors.forename: David H
authors.initials: DH
authors.lastname: Gultekin
authors.forename: Hebert Alberto
authors.initials: HA
authors.lastname: Vargas
authors.forename: Junting
authors.initials: J
authors.lastname: Zheng
authors.forename: Chaya
authors.initials: C
authors.lastname: Moskowitz
authors.forename: Xin
authors.initials: X
authors.lastname: Pei
authors.forename: Dahlia
authors.initials: D
authors.lastname: Sperling
authors.forename: Lawrence H
authors.initials: LH
authors.lastname: Schwartz
authors.forename: Hedvig
authors.initials: H
authors.lastname: Hricak
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Zelefsky
mesh_terms: D000368:Aged; D001707:Biopsy, Needle; D015331:Cohort Studies; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005069:Evaluation Studies as Topic; D019786:Gadolinium DTPA; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D007150:Immunohistochemistry; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness / Q000473:pathology; D009364:Neoplasm Recurrence, Local / Q000175:diagnosis* / Q000473:pathology; D009367:Neoplasm Staging; D011471:Prostatic Neoplasms / Q000473:pathology / Q000532:radiotherapy*; D012016:Reference Values; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012680:Sensitivity and Specificity
chemical_list: D019786:Gadolinium DTPA