1.How to treat hyperthyroidism
There are three main treatments for hyperthyroidism, including internal antithyroid drug (ATD) treatment, nuclear medicine iodine-131 treatment, and surgical treatment.
Internal ATD treatment is relatively mild, and the dosage can be adjusted in time during treatment. The disadvantage is that the treatment course is long, usually requiring 1-2 years of standardized treatment; during treatment, ATD can cause allergies, damage to liver and kidney function and hematopoietic system, and is often difficult to maintain once it occurs. Another shortcoming is that hyperthyroidism is prone to relapse when the drug is stopped or reduced, and the relapse rate of ATD treatment has been reported to be around 40-60%.
Iodine-131 treatment is easy to use and usually only one dose of iodine-131 is given. The symptoms of hyperthyroidism start to improve about 4 weeks after treatment, and the remission rate of hyperthyroidism usually reaches 75-80% in about one year. Iodine-131 treatment does not cause allergy, damage to liver and kidney function or hematopoietic function. Those hyperthyroid patients with allergy, abnormal liver and kidney function or decreased blood cells due to ATD treatment can still be treated. Some patients with no significant improvement or incomplete remission of symptoms after six months of iodine-131 treatment can be retreated with iodine-131 again. Patients with hyperthyroidism with severe proptosis should prefer surgical treatment.
Surgery is usually used to treat hyperthyroidism by subtotal thyroidectomy, which is a rapid treatment to relieve hyperthyroidism, especially for patients with significantly enlarged thyroid gland with proptosis and hyperthyroidism with nodules, but it is traumatic and may cause surgical complications such as damage to the recurrent laryngeal nerve and hypoparathyroidism in some cases. Some patients still have recurrence of hyperthyroidism after surgery.
At present, in the United States, iodine-131 therapy has become the preferred treatment for adult hyperthyroid patients, with about 80% or more of patients treated with iodine-131. In Europe, iodine-131 therapy for hyperthyroidism is also very important. In China, with the improvement of people’s awareness of hyperthyroidism and comprehensive understanding of radioactive iodine treatment for hyperthyroidism, more and more doctors and patients are choosing iodine-131 treatment for hyperthyroidism.
2. What kind of hyperthyroidism is suitable for radioactive iodine-131 treatment?
It is suitable for all diagnosed hyperthyroid patients, especially those with the following conditions: abnormal liver function, hypocellularity unsuitable for antithyroid drug (ATD) treatment; allergic to ATD drugs; relapse after ATD treatment; relapse after surgery or unwilling to operate.
Nodular goiter with hyperthyroidism; chronic lymphocytic thyroiditis (Hashimoto’s disease) with hyperthyroidism; simple goiter can also be treated with iodine-131 from the cosmetic point of view (in order to reduce the thickness of the neck).
3.What preparations should be made before iodine-131 treatment for hyperthyroidism?
Since iodine-containing foods, medications and antithyroid drugs have an effect on the uptake of iodine-131 by the thyroid gland, antithyroid drugs and iodine-containing foods and medications should be stopped for at least 4-6 weeks before treatment. Symptomatic treatment of hyperthyroidism symptoms such as panic attacks, low white blood cells and abnormal liver function should be continued during discontinuation of medication.
4.What tests should be done before iodine-131 treatment for hyperthyroidism?
Before taking iodine-131 treatment, patients with hyperthyroidism should have their thyroid iodine-131 uptake rate measured, biochemical indicators of thyroid function such as FT3, FT4 and TSH measured, thyroid antibodies such as A-Tg, A-TPO and TSH receptor antibodies (TRAb, TBII, etc.) measured, thyroid ECT imaging or ultrasound examination to clarify the size of the thyroid gland and determine the nature of thyroid nodules. The test will also include blood tests, liver and kidney functions, etc.
5.What is iodine-131? What are the medical uses?
Iodine-131 is a radioactive drug, an isotope of iodine, which decays by half every 8 days (half-life of 8 days); the beta rays it emits are used for therapeutic purposes. Iodine-131 accumulates only in the thyroid tissue and is not taken up by other tissues. The beta ray emitted by iodine-131 has a range of only 1 mm in the thyroid gland, and the energy it releases can destroy the hyperfunctional thyroid tissue and shrink the enlarged thyroid gland, just like having an operation, with little effect on the surrounding tissues.
6. Nuclear medicine examination of the thyroid is safe
The chemical amount of iodine-131 used in the determination of iodine absorption rate of thyroid gland is very small, the chemical amount of radioactive dose of 2 microjuice is 1.6×10-11 grams, which has no effect and no harm to human body.
The radioactive drug 99mTcO4-, which is commonly used for thyroid imaging, has a half-life of only 6 hours. The radioactive dose received by the patient is less than that of a single X-ray chest film. Iodine-131 can also be used for diagnostic imaging, but only in special cases such as searching for ectopic thyroid glands or looking for metastases of thyroid cancer.
7. Can hyperthyroidism treated with iodine-131 cause hypothyroidism?
All three methods of hyperthyroidism treatment (anti-thyroid drugs, iodine-131 and surgery) can cause hypothyroidism. As long as hyperthyroidism is cured and does not recur, a certain percentage of hypothyroidism occurs every year. Therefore the occurrence of hypothyroidism is not caused by iodine-131 treatment.
The incidence of hypothyroidism due to hyperthyroidism treated with iodine-131 varies from hospital to hospital at home and abroad, but in China it is mostly about 10%, and the trend is increasing year by year, and hypothyroidism is easy to diagnose and treat.
8.Iodine-131 can cure hyperthyroidism and you can still have children
After six months of iodine-131 treatment, you can get pregnant after your hyperthyroidism symptoms are relieved and biochemical indicators of thyroid function return to normal. Even if hypothyroidism occurs after treatment of hyperthyroidism, those who have normal biochemical indicators of thyroid function through drug (commonly used as eugenol) substitution therapy can also get pregnant, and can continue to take eugenol during pregnancy and breastfeeding, but the dosage needs to be adjusted by the doctor.
9. Not all hyperthyroid patients are suitable for iodine-131 treatment
Patients who are pregnant or breastfeeding and patients in the acute phase of acute myocardial infarction cannot be treated with iodine-131;
Iodine-131 therapy is also not suitable for patients with severe kidney impairment, because all iodine-131 is excreted in the urine except for the thyroid gland. If the kidney function is poor, iodine-131 cannot be eliminated in the body in time, and iodine-131 accumulates in the body, especially in the kidney for a long time exposing the patient to unnecessary exposure. Iodine-131 treatment can be used after the renal function is relieved.
10. Can anti-thyroid drugs and iodine-131 therapy be taken together for hyperthyroid patients?
Since antithyroid medication can affect the uptake of iodine-131 by the thyroid gland and the biochemical measurements of thyroid function, the patient should generally stop taking antithyroid medication (ATD) and abstain from iodine-containing food and medication for more than 2-4 weeks before undergoing the relevant nuclear medicine examination and treatment. However, in severe hyperthyroidism, because of the patient’s poor general condition, in order to prevent the aggravation of the disease or the emergence of hyperthyroidism crisis, the drug is usually stopped only three days before the determination of the iodine absorption rate of the thyroid gland, and the ATD treatment is continued for 2-4 weeks after taking iodine-131 for three days, and then the dosage is reduced or stopped under the guidance of the doctor.
11. Can I get rid of proptosis after Iodine-131 treatment?
There are three types of hyperthyroidism with proptosis: some appear before the onset of hyperthyroidism, some appear during the treatment of hyperthyroidism, and a few patients may appear after the control of hyperthyroidism or even when they have hypothyroidism. There is no specific treatment for hyperthyroidism with proptosis. In general, most of the hyperthyroidism proptosis is reduced after Iodine-131 treatment, but in very few patients, the proptosis is still aggravated after the hyperthyroidism symptoms are controlled.
12.What should I do if I have low thyroid?
Once diagnosed, the treatment of hypothyroidism is relatively simple, using thyroid hormone (eugenol) replacement therapy to bring the patient’s thyroid hormone levels to normal. As this treatment only replenishes the insufficient thyroid hormone in the patient’s body, it will not cause any damage to the patient’s liver, kidney function or hematopoietic system, nor will it affect pregnancy or breastfeeding, as long as the thyroid hormone level in the body is adjusted to the normal range. It is just like buying food to eat when you cannot grow your own food.