Combination Drug Therapy for Bone Regeneration Using a Model of Distraction Osteogenesis Following Radiotherapy
The prevalence of head and neck cancer (HNC) although high, comes with a variety oftreatment options. Radiation is often used to either destroy cancer cells or as an additional supportive therapy following tumor extirpation. Distraction osteogenesis (DO) is a surgical method for new bone reconstruction that helps remediate side effects from radiation. This method, although less invasive than the typical bone grafting procedure, leaves patients vulnerable to infection as the time required for recovery is lengthy. Reduction of the recovery period would be beneficial to both patients and the procedure potential. Drug treatments like Amifostine (AMF) and Deferoxamine (DFO) have been shown to reduce the length of rehabilitation by acting as a cellular radioprotectant and promoting angiogenesis, respectively. In this study, Sprague-Dawleyrats were used to understand how a combined therapy ofAMF and DFO would compare to the singular treatments. The combination therapy was hypothesized to show improvement ofunion rates in bone with bony bridging,_and increased strength in the yield load, stiffness, and failure load in relation to biomechanics in a model of distraction osteogenesis following radiotherapy. However, results show that while the combination therapy showed a higher union rate than either therapy alone, it was not statistically different from the DFO group. The results also suggested only a preservation of biomechanical strength as opposed to desired improvement. Due to the overall general trend of improvement observed, usage of the combination therapy is suggested for the best outcomes in distraction osteogenesis following radiotherapy. Further directions include corroborating the evidence gained with vascular and histologic data to investigate additional metrics of bone healing.