Effect of Radiation on DCE-MRI Pharmacokinetic Parameters in a Rabbit Model of Compromised Maxillofacial Wound Healing: A Pilot Study

Abstract Purpose Osteoradionecrosis (ORN), a potentially debilitating complication of maxillofacial radiation, continues to present a challenging clinical scenario, as treatment options are limited and often fail. Translational animal models that accurately mimic the human characteristics of the condition are lacking. This pilot study aimed to characterize the effects of radiation on dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) pharmacokinetic parameters in a rabbit model of compromised maxillofacial wound healing in order to determine its potential as a translational model of ORN. Methods An experimental group of rabbits (n = 8) received fractionated radiation of the mandible totaling 36 Gy. Four weeks after irradiation, both the experimental group and control group (n = 8) underwent a surgical procedure to create a critical size defect in the mandibular bone. DCE-MRI images were acquired one week after arrival (baseline; timepoint 1), four weeks after completed irradiation of the experimental group (just prior to surgery, timepoint 2), and four weeks after surgery (timepoint 3). Results No difference in the analyzed DCE-MRI parameters were noted within each experimental or control group when comparing baseline values (timepoint 1) to those after irradiation (timepoint 2). vb in the experimental group was increased compared to the control group after irradiation (timepoint 2; p Conclusion The results of this study suggest DCE-MRI imaging of a rabbit model of compromised maxillofacial wound healing may reflect the DCE-MRI characteristics of human patients with ORN and those at risk for developing the condition. Future studies will focus on further characterization of this rabbit model as a translational pre-clinical model of ORN.