Thyroid 4b is not necessarily cancer. 4b represents a grading of thyroid nodules, indicating that the nodules have two signs of malignancy, and the malignancy rate is between 10% and 50%, so there is only a possibility of malignancy, but not a confirmed diagnosis. So the patient needs to do further fine needle aspiration cytology of the nodule. If the test is negative, the nodule needs to be observed by regular follow-up ultrasound, for example, once in 3-6 months. If the fine needle aspiration indicates a positive result, the patient needs to be treated with surgery promptly, and also to observe whether the thyroid nodule is accompanied by changes in the lymph nodes in the neck. If there are metastatic changes in the lymph nodes, surgery is also needed and further iodine 131 treatment is required after surgery.