Assessment of the hamster cheek pouch as a model for radiation-induced oral mucositis, and evaluation of the protective effects of keratinocyte growth factor using this model.

PURPOSE: Oral mucositis induced by radiotherapy impacts quality of life. Previous studies have reported on the use of the hamster as a model for radiation-induced oral mucositis; however, details regarding factors such as radiation dose response, effects on myeloperoxidase (MPO) activity and related histopathological changes remain unclear. In the present study using the hamster, we evaluated the dose dependency of radiation-induced oral mucositis and the effects of keratinocyte growth factor (palifermin). METHODS: Oral mucositis was induced in the cheek pouch by X-irradiation using single doses in the range 20-50 Gy. To evaluate the protective effect of palifermin, administration was carried out (5 mg/kg) on days 1, 2 and 3 or on days 9, 10 and 11 after single irradiation at a dose of 40 Gy. RESULTS: The oral mucositis score, MPO activity and histopathological findings of inflammation increased in a dose dependent manner. Palifermin treatment stimulated the proliferation of mucosal epithelial cells. Additionally, palifermin when administered on days 1, 2 and 3 after irradiation (40 Gy) reduced the severity of oral mucositis. CONCLUSIONS: The hamster was found to be a suitable model for radiation-induced oral mucositis, with excellent results regarding the evaluation of radiation dose response and drug reactivity.