The Effects of Extracorporeal Shock Wave Therapy on Cutaneous Radiation Injury in a Mouse Model

Background: Although radiation-induced skin injuries are a concern in patients receiving radiation therapy, there are few effective treatments. The aim of this study was to evaluate the protective effects of extracorporeal shock wave therapy (ESWT) on irradiated fibroblasts and mouse skin. Methods: In this in vitro study of human dermal fibroblasts, the experimental group was subjected to ESWT after irradiation (20 Gy). The control groups were only irradiated or only subjected to ESWT. At 24 or 48 hours after ESWT, cell viability, cell migration, and mRNA and protein expression were measured. In the in vivo study, the experimental group (7 mice) was treated with ESWT after irradiation (45 Gy). The control group (7 mice) was only irradiated. At 8 weeks after irradiation, dorsal skin was harvested for histopathologic examination and protein isolation. Results: In dermal fibroblasts, treatment with ESWT increased viability of irradiated cells compared with irradiated-only and untreated cells ( P = 0.005). ESWT increased cell migration 24 hours after irradiation ( P = 0.002) and decreased transforming growth factor–β (TGF-β) protein expression 48 hours after irradiation ( P = 0.024). In mice, ESWT decreased the level of radiation-related skin injury ( P = 0.006). Treatment of irradiated skin with ESWT decreased TGF-β1 ( P = 0.009) and phospho-Smad3 ( P = 0.009) protein expression, decreased myofibroblasts ( P = 0.047), and increased vessel density ( P < 0.001). Conclusion: This study demonstrated that ESWT alleviated radiation-induced fibrosis by downregulating TGF-β1 expression, suggesting the potential of ESWT for the treatment of radiation-induced fibrosis.