This depends on the tumor size and pathological staging. In case of papillary or follicular carcinoma larger than 1cm in diameter, I-131 treatment should be routinely performed to clear the residual thyroid and possible metastases or residual foci. Smaller tumors (≤1cm) without obvious invasion of surrounding tissues, lymph node metastasis and other invasive features may not be recommended for I-131 nail clearing treatment, but if the thyroid tissue has been completely excised, I-131 nail clearing treatment can be performed to facilitate follow-up. After the residual thyroid tissue is removed in these patients, recurrence and metastasis can be understood by testing Tg and I-131 imaging during follow-up. This simplifies the content of the follow-up examination.