@misc{oai:repo.qst.go.jp:00073110,
 author = {金, 小海 and Kakinuma, Shizuko and Yamada, Yutaka and Morioka, Takamitsu and Daino, Kazuhiro and Shimada, Yoshiya and 金 小海 and 柿沼 志津子 and 山田 裕 and 森岡 孝満 and 臺野 和広 and 島田 義也},
 month = {Aug},
 note = {Purpose: Since the nuclear accident in Fukushima Daiichi nuclear power plants, long-term low dose rate radiation exposure is concerned about health effects including cancer. There is an increasing interest in the radiation exposure effects of children with particularly high radiation susceptibility. Currently, highest incidence of thyroid cancer by ultrasound thyroid screening has become a serious problem in Fukushima. However, it is not clear whether thyroid carcinogenesis is associated with radiation exposure. The purpose of this study is to clarify the thyroid cancer risk after exposure at childhood using experimental mouse model.
Since the nuclear accident in Fukushima, long-term low dose rate radiation exposure is concerned about health effects including cancer. Specially radiation susceptible children have been worried. Currently, ultrasound thyroid screening has revealed increase of thyroid cancer. However, it is not clear whether the thyroid carcinogenesis is associated with radiation exposure. The purpose of this study is to clarify the thyroid cancer risk after exposure at childhood using experimental mouse model.
Method: B6C3F1 male and female mice were irradiated at 1 or 7 weeks of age with 0, 0.2Gy ,2Gy or 4Gy γ-ray doses. All mice were sacrificed when they became terminal condition or died. The pathological specimens of all organs and tumors were archived electronically as digital data. We performed the pathological diagnosis of thyroid lesions using archived samples then calculated the risks of thyroid lesion after exposure to radiation, such as dose-response relationship and effect of age at exposure.
Results and Conclusions: 
Histopathological examination of thyroid lesions revealed follicular cell hyperplasia, follicular or papillary adenoma or carcinoma. The incidence of follicular cell hyperplasia was highest than that of adenoma and carcinoma. In mice after irradiation at 1 week of age incidence of tumor (adenoma and carcinoma) shown an increasing tendency compared with mice after irradiated at 7 weeks of age. We will discuss the relation between the risks of each thyroid lesion and dose of radiation or age at exposure., ERR2018(44th European Radiation Research Congress)},
 title = {Effect of age at exposure on the incidence of thyroid lesions after  γ-ray irradiation in mice},
 year = {2018}
}