1.What is radioactive iodine therapy (131 iodine therapy) 131 iodine only aggregates in thyroid tissue and is not taken up by other tissues. Thyroid cancer is the most common tumor among human endocrine tumors, and most of them are well differentiated malignant tumors. Differentiated thyroid cancer cells generally retain the property that normal thyroid cells can take up and utilize iodine ions. When the thyroid gland is removed, the metastatic foci of thyroid cancer have the function of taking up 131 iodine. After the patient takes a certain amount of 131 iodine (solution or capsule) orally, the residual thyroid gland and metastases can take up 131 iodine to a high degree, and the beta radiation emitted by 131 iodine can effectively remove the residual thyroid tissue and kill the tumor cells. 2.What kind of thyroid cancer patients need 131 iodine treatment? Thyroid cancer is generally divided into four types according to pathological types: papillary, follicular, medullary and undifferentiated cancer. The first choice of treatment for thyroid cancer is surgery, while radioactive iodine treatment is only a further treatment after surgery, and the relationship between the two is sequential. Since differentiated thyroid cancer is less malignant and has a better prognosis, there is some controversy at home and abroad about the need for 131 iodine therapy after surgery for differentiated thyroid cancer. According to the latest foreign guidelines for thyroid cancer treatment, most patients with thyroid cancer should be treated with radioactive iodine after surgical resection, but for patients with microscopic thyroid cancer without lymph node metastasis and without risk factors for recurrence, the guidelines do not recommend routine postoperative 131 iodine treatment. In addition, for patients with poor liver and kidney function, low blood count or some advanced severe thyroid cancer such as intracranial hypertension and spinal cord compression due to brain metastasis or bone metastasis, although the cancer lesion can take up and gather a certain amount of radioactive 131 iodine, external radiotherapy is generally required before 131 iodine therapy because 131 iodine therapy may be life-threatening. 3.What are the benefits of 131 iodine therapy? The significance of postoperative radioactive iodine therapy for thyroid cancer is that: (1) 131 iodine can remove tiny thyroid cancer lesions that are difficult to detect in the thyroid tissue remaining after surgery, so as to reduce the rate of recurrence and metastasis; (2) 131 iodine-whole body imaging after radioactive iodine therapy can detect new metastases that cannot be detected by other imaging examinations; (3) by measuring the thyroglobulin in the blood ( (3) The measurement of thyroglobulin (Tg) in blood can monitor whether there is recurrence or metastasis, which is both sensitive and accurate, and facilitates follow-up; (4) Most of the local or distant metastases (such as lung, bone, brain, etc.) have good results after repeated 131 iodine treatment, which can be seen as a significant reduction of lesions, symptom reduction, and improvement of quality of life, and some patients can be cured. 4.Does 131 iodine treatment require hospitalization? 131 iodine not only releases beta rays, but also emits gamma rays, which have strong penetrating ability and may cause radiation hazards to patients themselves, patients in the same ward, as well as surrounding health care workers and other normal people. Therefore, shielding and isolation are required when high-dose 131 iodine treatment is administered. In addition, there is a large amount of radioactive excretion during the early stage of 131 iodine treatment, which requires a special sewage treatment system, otherwise it can seriously pollute the environment. Therefore, the entire early phase of 131 iodine treatment needs to be carried out under conditions of radiation isolation. In addition, patients may have various complications when receiving high dose 131 iodine treatment, and hospitalization allows early detection and treatment to reduce the occurrence of accidents. 5.Does 131 iodine treatment have big side effects? Normal tissue cells of human body have different characteristics from thyroid cancer cells. Except for normal thyroid tissue cells, other normal tissue cells seldom take up and gather 131 iodine, so the radiation hazard is relatively small. In the early stage of high-dose radioactive 131 iodine treatment, patients may experience some radiation side effects (such as upper abdominal discomfort, nausea, weakness, head and neck swelling, etc.) in varying degrees, but most of them are not serious and can be tolerated by patients or can be relieved after targeted treatment. A few patients may experience side effects such as menstrual disorders, dry mouth, dry eyes, and decreased blood count in the short term, which can basically recover on their own. The whole 131 iodine treatment process is relatively safe. Based on our years of experience and research data, there are generally no serious long-term side effects associated with the current 131 iodine treatment method. Occasionally, however, patients who have been treated with high doses of 131 iodine for a long period of time (in combination with other anti-tumor treatments) may experience more serious conditions such as bone marrow suppression, which are promptly identified by our medical staff and adjusted accordingly. The safety of the treatment will be further improved if the treated patients can actively cooperate with the medical staff and pay attention to their own radiation protection during the treatment period, and if the patients can care for each other.