What is the principle of isotope treatment for hyperthyroidism?

Many people cannot understand why we use isotopes to treat diseases like hyperthyroidism. In fact, isotope therapy is also called radioactive iodine 1311 therapy. This treatment method has appeared very early, but because of its large side effects, it is generally not used to treat hyperthyroidism, as it will affect the patient's other glandular organs.

Causes of Hyperthyroidism

Causes of hyperthyroidism include diffuse toxic goiter (also known as Graves' disease), inflammatory hyperthyroidism (subacute thyroiditis, painless thyroiditis, postpartum thyroiditis, and Hashimoto's hyperthyroidism), drug-induced hyperthyroidism (levothyroxine sodium and iodine-induced hyperthyroidism), hCG-related hyperthyroidism (transient hyperthyroidism due to vomiting of pregnancy), and pituitary TSH tumor hyperthyroidism.

Causes of Hyperthyroidism

Clinically, more than 80% of hyperthyroidism is caused by Graves' disease, which is an autoimmune disease of the thyroid gland. The patient's lymphocytes produce thyroid-stimulating immunoglobulin-TSI. Clinically, the TSI we measure is the thyrotropin receptor antibody: TRAb.

The cause of Graves' disease is currently unclear. It may be related to factors such as fever, lack of sleep, and mental stress, but clinically the cause of the disease cannot be found in the vast majority of patients. Graves' disease is often combined with other autoimmune diseases, such as vitiligo, alopecia, type 1 diabetes, etc.

Isotope therapy for hyperthyroidism

Isotope therapy is mostly used in European and American countries.

Isotope therapy is also called radioactive iodine 1311 therapy. This method was developed in the late 1940s. It mainly utilizes the beta rays emitted by 1311 iodine and the ability of the thyroid gland itself to concentrate iodine, and destroys the thyroid follicular epithelial cells through the biological effects of radiation, causing them to atrophy and reduce secretion, thereby achieving the purpose of treatment. During treatment, isotope-labeled iodine 1311 is injected into the blood circulation system. After being absorbed in large quantities by the thyroid gland, the iodine 1311 emits rays with a range of 0.5~2mm to destroy the thyroid tissue. Because the range of the rays is very short, they will not affect other nearby glandular organs.

Isotope therapy has both advantages and disadvantages. The advantages are high efficiency, good effect and low recurrence rate. The disadvantage is that there are some serious side effects, such as: it is easy to cause hypothyroidism, aggravate exophthalmos and other complications. Radioactive iodine can cause hypothyroidism in 6% of patients. Fortunately, the sequelae of most patients are mild and easily controlled.

Isotope treatment of hyperthyroidism has strict requirements on indications and contraindications. This method is suitable for patients over 30 years old, patients who have relapsed after long-term treatment with antithyroid drugs, patients with diffuse moderate thyroid enlargement, patients with allergic reactions to sulfonylurea antithyroid drugs, elderly patients with severe heart and liver complications, and those with contraindications to surgery. The following patients are not suitable for isotope treatment of hyperthyroidism: patients under 30 years old, those with severe renal insufficiency, pregnant and lactating women, and those with extremely enlarged thyroid gland and compression symptoms.