Abstract
Anaplastic thyroid carcinoma, a rare type of primary thyroid cancer, is one of the most aggressive neoplasms with a poor prognosis. Many cases are in the advanced stage at the time of the initial visit, and curative treatment is impossible. Because of the highly radioresistant nature of anaplastic thyroid carcinoma, this condition cannot be properly controlled with conventional radiotherapy. Herein, we report the case of a patient with anaplastic thyroid carcinoma who underwent hypofractionated radiotherapy, attained a complete response, and is still alive more than 10 years after treatment with no evidence of disease. To overcome the high radioresistance of anaplastic thyroid carcinoma, we administered 50 Gy in 10 fractions three times a week. Furthermore, we administered paclitaxel and carboplatin sequentially before and after radiotherapy. Consequently, the patient completed treatment and reached a complete response. He is still alive more than 10 years after treatment with no evidence of disease or severe adverse events. Hypofractionated radiation therapy may provide good control of locally advanced anaplastic thyroid carcinoma.