1. Is nuclear medicine examination of thyroid gland harmful to human body? Thyroid iodine-131 iodine absorption rate determination using iodine-131 dose is very small, commonly used 2 microcurie radioactive dose, no effect on the human body and harm. The radiopharmaceutical 99mTcO4- commonly used for thyroid imaging has a short physical half-life (6 hours). The radioactive dose received by the patient is lower than the dose of taking an X-ray chest X-ray. 2. What is Iodine-131? What is its use in medicine? Iodine-131 is a radioactive drug, isotope of iodine, its physical half-life is 8.04 days; it can emit gamma rays for imaging and beta rays for treatment to play a diagnostic and therapeutic role. As the synthesis of thyroxine in the body thyroid tissue requires the participation of iodine, iodine-131 can be gathered in the thyroid tissue, β-rays in the thyroid gland range of only 2 mm, which releases energy can destroy the hyperfunction of the thyroid tissue, so that the enlarged thyroid gland shrinks as if it had undergone a surgery. Therefore, Iodine-131 is mainly used in the treatment of hyperthyroidism such as Graves’ disease hyperthyroidism and Plummer’s disease hyperthyroidism and the treatment of hyperthyroidism, in addition, it can also be used in the determination of the thyroid function, thyroid imaging, and better differentiated thyroid cancer and its metastatic foci of the treatment and follow-up. 3.What should hyperthyroid patients do before Iodine-131 treatment? Since iodine-containing foods, medicines and anti-thyroid medicines may affect the uptake of iodine-131 by the thyroid gland, anti-thyroid medicines and iodine-containing foods and medicines should be discontinued for more than 4-6 weeks before treatment. During the withdrawal period, the patient’s hyperthyroidism symptoms such as panic, low white blood cells, liver function abnormalities, etc. should continue to symptomatic treatment. 4.What should be checked before taking Iodine-131 treatment for hyperthyroidism? Before taking Iodine-131 treatment, patients with hyperthyroidism should have the measurement of thyroid iodine-131 uptake rate, the measurement of biochemical indexes of thyroid function, such as TT3, TT4, FT3, FT4, TSH, the measurement of thyroid antibodies, such as TgAB, TPOAb, and the measurement of TSH receptor antibodies (TRAb, TBII, etc.), and the measurement of thyroid nucleoside imaging or ultrasonography in order to define the size of the thyroid gland and make a preliminary judgment of the nature of the thyroid nodules. The nature of thyroid nodules. 5.Can hyperthyroidism cause hypothyroidism after treatment with iodine-131? At present, the three methods of hyperthyroidism treatment (anti-thyroid drugs, iodine-131, surgery) can cause hypothyroidism. Therefore, hypothyroidism is not only caused by iodine-131 treatment. The incidence of hypothyroidism caused by iodine-131 treatment of hyperthyroidism is reported differently by various hospitals at home and abroad, mostly 10-25% in China, and there is a trend of increasing year by year, hypothyroidism is easy to diagnose and treat. 6.Can hyperthyroid patients be treated with anti-thyroid drugs and iodine-131 at the same time? Because anti-thyroid drug treatment will affect the thyroid gland’s uptake of iodine-131 and the results of thyroid biochemistry, generally should stop using anti-thyroid drugs (ATD) and avoid iodine-containing foods and drugs for more than 4 weeks and then carry out the relevant nuclear medicine examination and treatment, and after the treatment no longer use ATD treatment, only the use of anti-sympathetic nerve excitation, whitening, hepatoprotective drugs and other symptomatic treatment can be used. However, in severe hyperthyroidism patients, because the general state of the patient is poor, and the therapeutic effect of iodine-131 is slow, in order to prevent the aggravation of the condition or the emergence of hyperthyroidism crisis, generally only in the determination of iodine uptake rate of the thyroid gland three days before the suspension of the drug, and in the service of iodine-131 three days after the continuation of the use of ATD treatment until the therapeutic effect of iodine-131. 7.Hyperthyroidism with malignant proptosis, can it be recovered after iodine-131 treatment? According to different reports, 15-60% of hyperthyroid patients may have monocular or binocular protrusion, some protrusions appear before the onset of hyperthyroidism, some appear during the treatment of hyperthyroidism, and a small number of patients may have protrusions after hyperthyroidism is controlled or even when hypothyroidism is present. At present, there is a lack of effective methods for the treatment of hyperthyroid synophthalmos at home and abroad. Clinical practice shows that most of the hyperthyroidism protruding eyes are reduced after iodine-131 treatment, and the degree of protruding eyes is still aggravated after the control of hyperthyroidism in a very small number of patients, who should go to the ophthalmology department for further symptomatic treatment. 8.What are the treatments for Graves’ hyperthyroidism? What are the disadvantages? There are three main treatments for hyperthyroidism in Graves’ disease, including internal medicine anti-thyroid drug (ATD) treatment, nuclear medicine 131I treatment, and surgical treatment. The internal medicine ATD treatment is relatively mild, and the dosage can be adjusted in time during the treatment. The first disadvantage is the long duration of treatment, which usually requires 1-2 years of standardized treatment; during the treatment period, ATD can cause damage to the liver, kidney function and hematopoietic system, and it is often difficult to adhere to it once it occurs.One of the shortcomings of ATD treatment is that hyperthyroidism is prone to recur when stopping or decreasing the dosage of the drug, and it has been reported that the recurrence rate of ATD treatment is about 40-60%. 131I treatment is simple, usually only one dose of 131I, hyperthyroidism symptoms begin to improve about 4 weeks after treatment, generally in about a year the hyperthyroidism remission rate can reach 75-80%. 131I treatment does not cause liver, kidney function and hematopoietic function damage. Therefore, it is suitable for the treatment of those hyperthyroid patients whose liver and kidney functions are abnormal or blood cells are reduced due to ATD treatment. Some patients whose symptoms do not improve significantly or whose relief is incomplete after six months of 131I treatment can be retreated with 131I again.A major complication of 131I treatment is hypothyroidism, and studies have shown that hypothyroidism occurring within one year of 131I treatment (early-onset hypothyroidism) can be restored to normal in some people through thyroid hormone replacement therapy; however, hypothyroidism occurring after one year of 131I treatment (late-onset hypothyroidism) often require longer or lifelong thyroid hormone replacement therapy. In addition, in patients with hyperthyroidism with severe proptosis, surgical treatment should be used to avoid further exacerbation of the proptosis. Surgery is usually performed by subtotal thyroidectomy for hyperthyroidism, which provides rapid relief of hyperthyroidism symptoms and is especially suitable for patients with markedly enlarged thyroid glands and protruding eyes, as well as for patients with hyperthyroidism with nodules, but its shortcomings are traumatic, and in some cases it may result in laryngeal recurrent nerve damage, hypoparathyroidism and other surgical complications. After surgery, some patients still have recurrence of hyperthyroidism or hypothyroidism. 9. What are the advantages and disadvantages of hypothyroidism treatment? Once hypothyroidism is diagnosed, the treatment method is relatively simple, using thyroid hormone replacement therapy, the patient’s thyroid hormone level can be adjusted to normal, as the treatment is only to supplement the patient’s body with insufficient thyroid hormone, as long as the body’s thyroid hormone level is adjusted to the normal range, which will not cause damage to the patient’s liver and kidney function and hematopoietic system; it will also not affect the pregnancy and breastfeeding. However, when heart disease is accompanied by hypothyroidism, supplemental treatment should be started from a small dose.