1.What are the indications for radioactive iodine treatment of hyperthyroidism? The use of radioactive 131 iodine treatment for hyperthyroidism is subject to the following conditions: ① diffuse goiter and hyperfunction. ② Thyroidectomy with recurrence; because there is a greater possibility of injury to the recurrent laryngeal nerve or parathyroid glands during reoperation, it is not as safe as the use of 131 iodine treatment. Those who have serious organic lesions, such as heart disease, chronic nephritis, hypertension, liver cirrhosis, chronic bronchitis or lung disease, serious diabetes mellitus, mental disorder and organic lesions of the nervous system, should not be treated by surgery. ④ Those who are ineffective in long-term treatment with anti-thyroid drugs, or those who are allergic to drugs and should not be treated with drugs or have recurrence after stopping drugs. ⑤ Those who are unwilling to have surgery or those who are not suitable for surgery. (6) Patients with severe protruding eye lesions (most of the protruding eyes are reduced after 131 iodine treatment). 2.What are the relative contraindications for radioactive iodine treatment of hyperthyroidism? Relative contraindication means that it is better to consider other treatment methods under the following conditions. (1) nodular goiter with hyperthyroidism, scanning confirmed that there are cold nodules generally do not need 131 iodine treatment. Because of the difference in iodine uptake capacity, treatment with a larger dosage, the results are slightly worse, and often need repeated treatment, in this case should first consider surgical resection is appropriate. ② The total number of white blood cells in the peripheral blood is less than 3×109/liter, and 131 iodine can be used for treatment only after the improvement of white blood cell treatment. If the symptoms of hyperthyroidism are serious, thyroid crisis and heart failure can be induced, so it is better to control the symptoms with antithyroid drugs before 131 iodine treatment. 3.What are the absolute contraindications to radioactive iodine treatment of hyperthyroidism? Radioactive 131 iodine treatment is not applicable to the following cases: ① pregnant and lactating women, when the mother ingests 131 iodine, it can enter the thyroid gland of the fetus or the baby through the placenta and breast milk, which will cause cretinism of the fetus and the baby. ② huge goiter has produced tracheal compression symptoms, often not easy to eliminate the compression symptoms after taking 131 iodine, the individual instead of aggravation, and the thyroid gland is too large may often hide undetectable thyroid cancer. The patient with severe liver and kidney diseases. 4, radioactive iodine treatment of hyperthyroidism before what should be prepared? If radioactive iodine is used for hyperthyroidism treatment, the following preparations should be made in advance: ① Avoid iodine and other iodine-containing foods or drugs for 2-4 weeks before taking 131 iodine. ② 131 iodine treatment before the seriousness of the condition, the heart rate of more than 160 times / minute, serum T3, T4 significantly increased, it is appropriate to use anti-thyroid drugs or cardiac glycosides and other treatments, until the symptoms are reduced, before 131 iodine treatment. ③Patients using antithyroid drugs need to stop the drugs, Tabazolol stop about 3-5 days, PTU need to stop for 2 weeks, and then make 131 iodine uptake rate measurement, then 131 iodine treatment can be used. ④ Conventional tests such as blood, urine and chest X-ray should be performed to understand the function of major organs. ⑤ Perform 131 iodine uptake rate of the thyroid gland and thyroid scanning in order to calculate the drug dose. ⑥ Explain the precautions related to 131 iodine treatment to the patient. ⑦ A few days before and after taking 131 iodine, the patient should take bed rest and avoid strenuous activities. 5.What is the effect of radioactive iodine treatment for hyperthyroidism? In the treatment of hyperthyroidism with 131 iodine, if the indications are properly selected, the dosage and the method of administration are correct, and the patient and the doctor cooperate with each other, the effective rate is more than 90%. After taking the medicine, the effect will appear in 3~4 weeks, then the symptoms will be reduced month by month, the thyroid gland shrinks, the weight increases, and in 3~4 months, most of the patients can reach the normal level of thyroid function, and the effect of 131 iodine is slow in a small number of patients, and the symptoms will only be gradually improved after taking the medicine for 6 months. Generally speaking, about 50% to 80% of the patients are cured in one course of treatment, about 20% to 40% of the patients are cured in the second course of treatment, and very few patients need the third course of treatment. 6.How to repeat the treatment after taking 131 iodine? After taking 131 iodine, it takes more than 3 months for the thyroid function to return to normal, and in some cases, it takes 6 months to one year for the patient to be relieved. About 2/3 of the cases can be cured at one time, and 1/3 of the cases need to be treated by 2 or more courses of treatment. After the first dose of 131 iodine, the second treatment should be considered only after an interval of at least 6 months according to the patient’s condition, in order to minimize the occurrence of hypothyroidism complications. The dose of the second treatment should be based on the response after the first treatment. If the amount of 131 iodine is insufficient in the first treatment, the dose of the second treatment should be increased appropriately, and the increase is about 50% of the dose of the first treatment; if there is a relapse after the improvement in the first treatment, then the dose of the second treatment should be increased by 25% compared with that of the previous treatment; if symptoms are improved, but not cured, the dose of the second treatment can be estimated appropriately according to the situation. The calculation method of the dose after the second time is the same as that of the second time in principle. 7.What should I pay attention to after taking 131 iodine? In order to get the best therapeutic effect of 131 iodine in the treatment of hyperthyroidism, attention must be paid to the following aspects: ① Eat only after 2 hours of taking 131 iodine on an empty stomach, so as not to affect the absorption of iodine. ② after taking 131 iodine, generally 3 weeks after the beginning of the efficacy, in the clinical symptoms have not yet begun to improve a stage, should not be used arbitrarily iodine, bromine and anti-thyroid drugs, so as not to affect the reabsorption of 131 iodine, reduce the efficacy of the treatment. Low iodine diet for 2 to 4 weeks after treatment, no seaweed, nori and other sea plants. ③Patients should pay attention to rest for a few days after taking 131 iodine, avoid strenuous activities and mental stimulation, and prevent infection. ④ As the symptoms of radiation thyroiditis such as neck itching and pain can be seen in the early stage of 131 iodine treatment, patients should avoid looking at or squeezing the thyroid gland in the first week after treatment. 8.What are the early toxic reactions of radioactive iodine treatment for hyperthyroidism? The treatment of hyperthyroidism with 131 iodine is relatively simple, the curative effect is certain, most of them have no adverse reactions, and a few of them may have some side effects and complications. Adverse reactions are generally categorized into early toxic reactions and late complications. Early toxic reaction refers to the reaction that occurs within 2 weeks after taking the drug, and the common situations are as follows: ① systemic reaction is often characterized by digestive symptoms, anorexia, nausea, vomiting, etc., and a few of them have skin itching, rash, dizziness, fatigue, etc., which can be disappeared after 2 to 3 days of symptomatic treatment. ② local reaction is more common, mainly thyroid edema and the manifestation of radiation thyroiditis, the patient’s neck itching, swelling and pressure, and even hypopharyngeal pain and cough, without special treatment, a few days or 1 week after the gradual disappearance. ③ In the first 2 weeks of treatment, some patients may have symptoms aggravated (elevated basal metabolic rate and serum protein-bound iodine concentration), at this time only need to bed rest or apply some sedatives and some β-blockers such as cardiac glycosides, etc., and can be gradually improved. Individual serious patients will appear hyperthyroidism crisis, manifested as mental uneasiness, high fever, sweating, rapid heartbeat (often more than 140 times / min), elevated pulse pressure, and even the occurrence of atrial fibrillation, diarrhea, and coma, etc., such as untimely treatment can often be life-threatening. This is due to radioactive damage to the thyroid follicles were destroyed, a large number of thyroxine release into the blood or many factors. Where the clinical symptoms are more serious, the thyroid gland is larger patients, give 131 iodine before taking thiourea drugs, give 131 iodine should be closely observed. Leukopenia, which mostly occurs after 131 iodine is administered, can be gradually recovered. 9. What should be done for hypothyroidism after radioactive iodine treatment? The treatment of hypothyroidism is very simple and can be easily corrected by giving thyroxine tablets. Hypothyroidism is one of the late complications after 131 iodine treatment, and this complication is a serious complication after 131 iodine treatment. Most of them occur between 2 and 6 months after treatment, while others appear much later or occur several years later. Temporary hypothyroidism often recovers on its own, but in a few cases it is permanent and requires lifelong replacement therapy with thyroid preparations.The incidence of hypothyroidism caused by 131 iodine therapy has been reported differently both at home and abroad, and the incidence gradually increases with the prolongation of the post-treatment period, and it has been reported domestically that, in the 64 cases followed up between 1958 and 1980, the incidence of long-term hypothyroidism was 25% in the first 2-5 years of the treatment, of which 25% was in the second 2-5 years. The incidence of long-term hypothyroidism after 131 iodine treatment was 25% in 2 to 5 years, which was related to the factor that thyroid function gradually becomes hypothyroidism with the increase of age due to the natural exhaustion of thyroid disease itself. At present, with the standardization of iodine-131 therapy, the incidence of hypothyroidism is generally around 5-15%. The reason for the occurrence of hypothyroidism is that ionizing radiation damages the nuclei of the thyroid epithelial cells, so that they cannot divide and regenerate, and the longer the period of time, the more hypothyroidism occurs; the second reason is that the dose of 131 iodine treatment is too large, destroying too much thyroid tissue, and it has been reported that some people can be induced to have hypothyroidism even though the dose is very small, and the third reason is that it may be associated with autoimmune reactions. How to reduce the occurrence of hypothyroidism after 131 iodine treatment is still a problem to be solved. 10.Can radioactive iodine treatment of hyperthyroidism aggravate proptosis? Severe progressive synophthalmos can occur spontaneously or after subtotal thyroidectomy, while fewer people develop synophthalmos after 131 iodine treatment. 131 iodine can make most (reported about 70%) patients’ synophthalmos improve after treatment, and only a few cases of synophthalmos aggravate. It is generally believed that 131 iodine can make the thyroid function gradually reduced, so the pituitary thyrotropin or synophthalmos-producing substances do not suddenly increase, so some scholars believe that the hyperthyroidism of patients with obvious synophthalmos is the indication for treatment with 131 iodine. 11.Does radioactive iodine have any effect on fertility and offspring? The therapeutic amount of 131 iodine has little effect on the reproductive organs of men and women, so their fertility is not affected after treatment, and the incidence of congenital malformations, stillbirths and preterm births of the offspring does not increase, and there is no significant difference between the incidence of infertility and that of the normal population. Although the radiation damage of a treatment volume is not as large as that of a gastrointestinal fluoroscopy, many scholars have conducted more in-depth studies. It has been observed that patients after 131 iodine treatment have chromosomal mutations, but they can gradually return to normal. Therefore, the risk of increased gene mutations and chromosomal aberrations after 131 iodine treatment is very low. However, considering the long-term effects and genetic effects of ionizing radiation, long-term follow-up observation is also needed to draw the correct conclusion. In order to safeguard the health of the next generation and intergenerational children, it is necessary to include pregnancy as a contraindication to 131 iodine treatment. Pregnancy is not allowed during treatment, and it is generally recommended that it is safe to consider a birth plan more than 6 months after treatment when the radioactivity in the body drops below background after 3 months of treatment.