Hypofractionated carcinoma of the thyroid, also known as undifferentiated carcinoma of the thyroid, is one of the four pathological types of thyroid cancer. There are currently four pathological types of thyroid cancer: the first, papillary carcinoma of the thyroid; the second, follicular carcinoma of the thyroid; the third, medullary carcinoma of the thyroid; and the fourth, undifferentiated carcinoma of the thyroid. Undifferentiated thyroid cancer accounts for about 5%-10% of thyroid cancer patients, mostly in the elderly, and its development rate is highly malignant, and about 50% of them have early metastasis of lymph nodes in the neck or early invasive symptoms, such as invasion of the laryngeal nerve causing hoarseness, invasion of the trachea and esophagus causing breathlessness and difficulty in swallowing, and early metastasis to distant places through blood flow. The metastasis can occur at an early stage via blood flow to distant places. The prognosis of undifferentiated thyroid cancer is relatively poor, and the average survival time is about 3 months to 6 months, and the chance of survival within 1 year is only about 5%-15%.