Radiation-induced mucositis: An animal model

Abstract

Problem: Radiotherapy usually plays an important role in the treatment of head and neck cancers. However, radiation-induced mucositis often occurs and interrupts the radiotherapy. Current studies cannot explain sufficiently the efficacy of medication for the radiation-induced mucositis. Because human studies of the effect of medication for mucositis are difficult, an animal model for radiation-induced mucositis must be used. Rat oral mucosa was locally irradiated for creating mucositis experimentally and a histological examination was performed. A pilot study for producing an animal model of radiation-induced mucositis is discussed. Methods: Eight rats were divided into 4 groups. These 4 groups were classified by the direction of irradiation and the degree of 1-day irradiation. Rats in each group were anesthetized by ketamine hydrochloride and irradiated using LINAC (6MeV X-ray irradiated machine). Macroscopic observations of the rat oral mucosa were performed and recorded day by day. Once oral mucositis was created, all rats were euthanized. Obtained oral specimen of mucositis was used for histological examination. Results: One of 8 rats created oral aphtha and ulcer at the total dose of 100 Gy (4 Gy/day) over a period of 25 days. Microscopic examination showed that numerous inflammatory small round cells were infiltrated around ulcers under hematoxylin-eosin stain. Conclusion: This pilot study presented a rat model of radiation-induced mucositis. In human beings, oral mucositis is usually created at the total amount of 40 Gy under 2 Gy/day irradiation. However, comparing between human being and rat, rats need about 2 to 3 the dosages of irradiation than do human beingss for creating oral mucositis. The explication of irradiation tolerance at the rat oral mucosa might play an important role for producing a new technique that treats radiation-induced mucositis in human oral mucosa. Significance: A rat model might be useful for producing a new technique for treating radiation-induced mucositis in human oral mucosa. Support: None reported.