1. Relationship between thyroid and iodine The thyroid gland uses iodine to synthesize thyroid hormones. Iodine is essential for the thyroid gland to perform its normal functions, and there is an active system (or pump) in the thyroid gland through which iodine enters the thyroid cells. Zheng Shouhua, General Surgery Department, Zhengzhou University First Affiliated Hospital 2. What is radioactive iodine There are two types of radioactive isotopes of iodine: I123 (harmless to thyroid cells) and I131 (can destroy thyroid cells). Radioactive iodine is safe for patients who are allergic to seafood or to X-ray contrast agents because it is an allergy to iodine-containing complexes, not to iodine. 3. Radioactive iodine for thyroid imaging I123 is harmless to thyroid cells and is used for thyroid imaging and to determine the function of the thyroid gland. No special tests are needed before thyroid imaging or to determine the function of the thyroid gland. 4. radioactive iodine for thyroid disease Normal thyroid tissue: I131 is used to destroy hyperfunctioning thyroid tissue, or thyroid function is normal, but shrink the thyroid gland when discomfort is caused by an enlarged gland, which requires some pretreatment. mild pain after I131 treatment can be treated with aspirin, ibuprofen, acetaminophen. The effect of radioactive iodine treatment may take several months to be seen. Thyroid cancer-High dose I131 is used to destroy thyroid cancer cells. It needs to be isolated in the hospital for 24 hours after treatment so that the radiation does not affect other people, especially children who are in close contact. Pain and swelling after high dose I131 treatment can be reduced or prevented by drinking plenty of water or lemon juice. 5, I131 treatment precautions Because I131 can produce radiation, patients should avoid contact with other people (especially pregnant women and children) to reduce the dose of radiation received by others. The radiation dose decreases significantly with distance. If you need to travel after I131 treatment, it is best to bring a letter of explanation from your doctor. This is because detection equipment at airports or in some buildings may alert you, and you should discuss the issue in detail with your doctor before and during radioactive iodine treatment. 6. Long-term risks of I131 therapy In general, radioactive iodine therapy is safe and effective for thyroid disorders (described above). Hypothyroidism is a common side effect of radioactive iodine therapy, but is easily treated. Some studies suggest a slight increase in the incidence of thyroid cancer after radioactive iodine therapy. Loss of taste and dry mouth after radioactive iodine therapy can be prevented by drinking lemon juice. The incidence of other tumors may also increase after radioactive iodine treatment. Most importantly, as long as you have received radioactive iodine treatment, you should receive regular follow-up throughout your life. 7. Special precautions for female patients Radioactive treatment, whether I123 or I131, should not be used for pregnant or breastfeeding women. Pregnancy should occur at least 6?D12 months after I131 treatment, as the ovaries are similarly damaged by radioactivity. Evidence that radioactive iodine treatment causes infertility is unclear, but menopause can be advanced. 8. Special considerations for men Male patients who have undergone radioactive iodine treatment can experience a decrease in sperm count and temporary infertility for approximately two years. Male patients who have received several courses of radioactive iodine treatment and require fertility may consider sperm bank artificial insemination or pre-stored sperm.