Use of 60Co panoramic source in the induction of oral mucositis in rats

Oral Mucositis is a well-known side effect of chemo-radiotherapy in cancer patients or transplant recipients that could induce hospitalization or impairs therapy in different levels of severity. This study is devoted to define the first steps in the research of low level laser treatments in oral mucositis, proposing a 60Co radiation to experimentally induce oral mucositis in rats using Panoramic gamma irradiator, simulating usual radiotherapy of head and neck cancer. Fifteen male Wistar rats, above 250g, were irradiated at Centro de Tecnologia das Radiacoes (IPEN - CNEN/SP) and divided in three experimental groups, with different single doses of radiation (30 Gy, 25 Gy and 20 Gy). The animals were observed for a 20 days period. Animals that received 30 Gy and 25 Gy developed greater severity of mucositis and premature euthanasia was performed in these groups on the 7th and 11th day after the irradiation, respectively. The 20 Gy group developed oral mucositis grading from moderated to severe between the days 7 and 11 after irradiation, with progressive body mass loss and decrease in the intake of food and water. These animals recovered from oral mucositis around the 18th day and clinical remission at the 20th day. The single dose of 20 Gy Gamma radiation proved to be efficient way for inducing oral mucositis in rats, allowing the establishment of an experimental model for oral mucositis in rats for future use on interventions of this serious aspect of radiation therapy, such as laser therapy using different wave lengths and power densities. (author)