Abstract: Papillary thyroid carcinoma(PTC) is one of the most common malignant tumors in the endocrine and head-neck system. Surgical resection is the mainly treatment used in advanced PTC patients, and ¹³¹I is used as adjuvant treatment. However, nearly 30% of patients suffering from tumor dedifferentiation fail to uptake iodine after thyroid cancer surgery; thus, these patients lose the opportunity to undergo postoperative ¹³¹I treatment. Recently, with the rapid increase in the incidence of thyroid cancer, the number of such patients has increased dramatically, and radiation therapy gradually plays an important role in the adjuvant therapy. Although radiotherapy has been limited for advanced PTC patients in the past, with the development of radiotherapy technology, external-beam radiotherapy(EBRT) has slowly displayed its greatest superiority for these patients.