title: A role for dynamic contrast-enhanced magnetic resonance imaging in predicting tumour radiation response.
abstract: Dynamic contrast-enhanced (DCE) MRI may provide prognostic insights into tumour radiation response. This study examined quantitative DCE MRI parameters in rat tumours, as potential biomarkers of tumour growth delay following single high-dose irradiation.
  
  
  
  Dunning R3327-AT1 prostate tumours were evaluated by DCE MRI following intravenous injection of Gd-DTPA. The next day tumours were irradiated (single dose of 30 Gy), while animals breathed air (n=4) or oxygen (n=4); two animals were non-irradiated controls. Growth was followed and tumour volume-quadrupling time (T4) was compared with pre-irradiation DCE assessments.
  
  
  
  Irradiation caused significant tumour growth delay (T4 ranged from 28 to 48 days for air-breathing rats, and 40 to 75 days for oxygen-breathing rats) compared with the controls (T4=7 to 9 days). A strong correlation was observed between T4 and extravascular-extracellular volume fraction (ve) irrespective of the gas inhaled during irradiation. There was also a correlation between T4 and volume transfer constant (K(trans)) for the air-breathing group alone.
  
  
  
  The data provide rationale for expanded studies of other tumour sites, types and progressively patients, and are potentially significant, as many patients undergo contrast-enhanced MRI as part of treatment planning.
authors.affiliation: Department of Radiology, UT Southwestern, 5323 Harry Hines Boulevard, Dallas, TX 75390, USA.|Analytical Imaging and Modeling Center, Children's Medical Center, Dallas, 1935 Medical District Dr, Dallas, TX 75235, USA.
authors.forename: Rami R
authors.initials: RR
authors.lastname: Hallac
authors.affiliation: Department of Radiology, UT Southwestern, 5323 Harry Hines Boulevard, Dallas, TX 75390, USA.
authors.forename: Heling
authors.initials: H
authors.lastname: Zhou
authors.affiliation: Radiation Oncology, UT Southwestern, 5323 Harry Hines Boulevard, Dallas, TX 75390, USA.
authors.forename: Rajesh
authors.initials: R
authors.lastname: Pidikiti
authors.affiliation: Radiation Oncology, UT Southwestern, 5323 Harry Hines Boulevard, Dallas, TX 75390, USA.
authors.forename: Kwang
authors.initials: K
authors.lastname: Song
authors.affiliation: Radiation Oncology, UT Southwestern, 5323 Harry Hines Boulevard, Dallas, TX 75390, USA.
authors.forename: Timothy
authors.initials: T
authors.lastname: Solberg
authors.affiliation: Department of Radiology, UT Southwestern, 5323 Harry Hines Boulevard, Dallas, TX 75390, USA.|School of Biological and Health Systems Engineering, Arizona State University, Tempe, AZ, USA.
authors.forename: Vikram D
authors.initials: VD
authors.lastname: Kodibagkar
authors.affiliation: Department of Molecular Radiation Oncology, German Cancer Center, Im Neuenheimer Feld 280, Heidelberg 69121, Germany.
authors.forename: Peter
authors.initials: P
authors.lastname: Peschke
authors.affiliation: Department of Radiology, UT Southwestern, 5323 Harry Hines Boulevard, Dallas, TX 75390, USA.
authors.forename: Ralph P
authors.initials: RP
authors.lastname: Mason
mesh_terms: D000388:Air; D000818:Animals; D002277:Carcinoma / Q000000981:diagnostic imaging* / Q000473:pathology / Q000532:radiotherapy; D015687:Cell Hypoxia; D003287:Contrast Media; D019786:Gadolinium DTPA; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D010100:Oxygen / Q000008:administration & dosage / Q000494:pharmacology; D010102:Oxygen Inhalation Therapy; D011379:Prognosis; D011471:Prostatic Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology / Q000532:radiotherapy; D051381:Rats; D013848:Thigh; D016042:Transplantation, Heterotopic; D047368:Tumor Burden
chemical_list: D003287:Contrast Media; D019786:Gadolinium DTPA; D010100:Oxygen