Dynamic contrast-enhanced magnetic resonance imaging as a predictor of clinical outcome in canine spontaneous soft tissue sarcomas treated with thermoradiotherapy

Clin Cancer Res. 2009 Aug 1;15(15):4993-5001. doi: 10.1158/1078-0432.CCR-08-2222. Epub 2009 Jul 21.


Purpose: This study tests whether dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) parameters obtained from canine patients with soft tissue sarcomas, treated with hyperthermia and radiotherapy, are predictive of therapeutic outcome.

Experimental design: Thirty-seven dogs with soft tissue sarcomas had DCE-MRI done before and following the first hyperthermia. Signal enhancement for tumor and reference muscle were fitted empirically, yielding a washin/washout rate for the contrast agent and tumor area under the signal enhancement curve (AUC) calculated from 0 to 60 seconds, 90 seconds, and the time of maximal enhancement in the reference muscle. These parameters were then compared with local tumor control, metastasis-free survival, and overall survival.

Results: Pretherapy rate of contrast agent washout was positively predictive of improved overall and metastasis-free survival with hazard ratio of 0.67 (P = 0.015) and 0.68 (P = 0.012), respectively. After the first hyperthermia washin rate, AUC60, AUC90, and AUCt-max were predictive of improved overall and metastasis-free survival with hazard ratio ranging from 0.46 to 0.53 (P < 0.002) and 0.44 to 0.55 (P < 0.004), respectively. DCE-MRI parameters were compared with extracellular pH and (31)P MR spectroscopy results (previously published) in the same patients showing a correlation. This suggested that an increase in perfusion after therapy was effective in eliminating excess acid from the tumor.

Conclusions: This study shows that DCE-MRI has utility predicting overall and metastasis-free survival in canine patients with soft tissue sarcomas. To our knowledge, this is the first time that DCE-MRI parameters are predictive of clinical outcome for soft tissue sarcomas.

Publication types

  • Evaluation Study
  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Animals
  • Combined Modality Therapy / veterinary
  • Dog Diseases / diagnosis*
  • Dogs
  • Hyperthermia, Induced / veterinary
  • Image Enhancement
  • Kaplan-Meier Estimate
  • Magnetic Resonance Imaging / methods
  • Magnetic Resonance Imaging / veterinary*
  • Prognosis
  • Radiotherapy / veterinary
  • Radiotherapy Dosage / veterinary
  • Sarcoma / diagnosis
  • Sarcoma / pathology
  • Sarcoma / veterinary*
  • Soft Tissue Neoplasms / diagnosis
  • Soft Tissue Neoplasms / pathology
  • Soft Tissue Neoplasms / veterinary*
  • Treatment Outcome