1, what is the thyroid gland The thyroid gland is a butterfly-shaped gland, consisting of two wings (left and right lobes) and the middle part (isthmus) connected, resembling the “H” shape, located in front of the neck, weighing about 20-30 grams, can move up and down with swallowing. The main function of the thyroid gland is to produce thyroid hormone. 2. What is thyroid hormone Thyroid hormone is produced by the thyroid gland, which includes TT3, TT4, FT3 and FT4. The thyroid gland has a strong aggregation effect on iodine, accounting for about 80% of the total body iodine content. The thyroid gland takes iodine from the blood (most of it comes from food such as seafood, bread and salt) and uses it to produce thyroxine, which is important for human growth and development and organ function regulation, and can control the speed of human metabolism. 3.What is 131 iodine? 131 iodine (131I) is a radioactive drug, an isotope of iodine with the same chemical properties as iodine, but unlike ordinary iodine, it can emit gamma rays for imaging and beta rays for treatment, thus playing a diagnostic and therapeutic role. 4.What is meant by 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, most of which 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, which is called “radioactive iodine therapy”. 5.Which thyroid cancer patients need 131 iodine treatment? Generally, thyroid cancer is divided into four types according to the pathological type: papillary carcinoma, follicular carcinoma, medullary carcinoma and undifferentiated carcinoma. The first choice of treatment for thyroid cancer is surgery, while radioactive iodine treatment is only a further treatment after surgery. 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, 131 iodine treatment may be life-threatening, so external radiotherapy is usually required before 131 iodine treatment. 6.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 microscopic thyroid cancer lesions that are difficult to detect in the thyroid tissue after surgery, so as to reduce the recurrence and metastasis rate; (2) 131 iodine-systemic imaging after radioactive iodine therapy can detect new metastases that are not detected by other imaging examinations; (3) By measuring the blood (4) Most local or distant metastases (e.g. 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. 7.Does 131 iodine therapy have big side effects? The 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 aggregate 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.) to 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 antitumor therapies) 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 during the treatment period and pay attention to their own radiation protection, and if the patients can care for each other.