The thyroid gland and its functions
The thyroid gland is divided into two lobes, the right and left, and is located in the front of the neck below the thyroid cartilage, on either side of the trachea, and is shaped like a butterfly. The adult thyroid gland weighs about 15 to 25 grams and is neither clearly visible nor easily palpable under normal circumstances. There are four parathyroid glands on the back of the two lobes of the thyroid gland, and the thyroid gland is surrounded by important structures such as the recurrent laryngeal nerve and the superior laryngeal nerve.
The thyroid gland has the function of synthesizing, storing and secreting thyroid hormones (T3 and T4). The main function of thyroid hormones is to increase the breakdown of proteins, fats and sugars, increase the production of heat, and promote human growth and development. Normal people need a certain amount of thyroid hormones to maintain normal physiological functions.
Hyperthyroidism (hyperthyroidism)
Hyperthyroidism is caused by an abnormally high level of thyroid hormones in the patient’s blood. It can be divided into five categories according to the cause, among which toxic diffuse goiter (Graves’ disease) is the most common, with an age of onset of 20-40 years, and is significantly higher in women than in men.
The common clinical manifestations of hyperthyroidism are.
1. Enlargement of the thyroid gland, i.e., thickening of the “neck”;
2. Protrusion of the eyeballs;
3. Hyper-synthesis, manifested as fear of heat and sweating, panic and fatigue, hyper-appetite, thinning, short temper, hand trembling, etc., which may not be typical in elderly people.
Diagnosis of hyperthyroidism: Nuclear medicine can provide accurate and reliable diagnosis of hyperthyroidism. For first-time patients, a comprehensive examination of thyroid function should be performed to make an accurate diagnosis.
The routine tests are
1, serum thyroid hormone measurement (including TT3 TT4 TSH FT3 FT4 TG TM)
2.Iodine uptake measurement of thyroid gland
3.Thyroid nuclear scan
Treatment options for hyperthyroidism.
1.Medical anti-hyperthyroidism drug treatment
2.Surgical treatment
3.Isotope 131 iodine treatment
All three types of treatment are effective, but surgery is rarely used due to the risk of trauma; internal anti-hyperthyroidism medication is the most widely used, but it can only achieve a cure rate of 40-60%, and the recurrence rate of hyperthyroidism is very high after stopping medication. The most common side effects are leukopenia, liver toxicity, and the most serious and life-threatening one is granulocyte deficiency. The cure rate of 131 iodine treatment for hyperthyroidism is positively correlated with the dose of 131 iodine treatment. The cure rate of 131 iodine treatment is positively correlated with the dose of 131 iodine treatment. The overall cure rate is over 80%, the failure rate is 2%-4%, and the relapse rate is 1%-4%. The best results are achieved in patients with diffuse goiter with moderate hyperthyroidism.
Isotope 131 radioactive iodine treatment for hyperthyroidism
Why can radioisotope 131 iodine treat hyperthyroidism?
The reason why 131 iodine can treat hyperthyroidism is that most of the 131 iodine enters the body and accumulates in the thyroid gland, releasing beta radiation during the decay of 131 iodine. This ray has a range of only 2 mm in the thyroid gland, and the energy it releases can destroy the hyperfunctional thyroid tissue and shrink the enlarged thyroid gland as if it had undergone an operation. Therefore, 131 iodine treatment for hyperthyroidism has been described as “bloodless surgery”. Through thyroid hormone measurement, thyroid function tests, and the combination of thyroid size and degree of hyperthyroidism, patients are given a certain amount of 131 iodine, which destroys part of the hyperfunctional thyroid tissue while preserving part of the normal thyroid tissue, to treat hyperthyroidism. Generally speaking, more than 80% of patients with hyperthyroidism can have their symptoms and signs rapidly controlled and cured by 131 iodine treatment.
Indications for radioisotope 131 iodine treatment for hyperthyroidism
1. Age 20 years or older, with moderate hyperthyroidism.
2. Patients who are allergic to antihyperthyroid drugs and cannot continue to use them, or whose long-term treatment is ineffective, or who relapse after treatment.
3, Combination of heart, liver and kidney diseases that are not suitable for surgery, or recurrence after surgery, or unwillingness to operate.
4. Certain high-functioning nodules with hyperthyroidism.
Safety of radioisotope 131 iodine treatment for hyperthyroidism
In most cases, the radioactive dose to the thyroid gland only causes destruction and occlusion of the thyroid tissue, and most of the thyroid cells are killed rather than mutated.
On the question of whether 131 iodine treatment of hyperthyroidism induces thyroid nodules, cancer and genetic complications, from decades of follow-up reports and an extensive literature review, no convincing evidence has been found to date that the treatment increases the risk of nail and other carcinomas, leukemia, infertility, preterm birth, miscarriage, birth defects and genetic complications.
What is the diagnosis and treatment of hypothyroidism after radioisotope 131 iodine treatment for hyperthyroidism?
Hypothyroidism can occur regardless of the method of treatment for hyperthyroidism, so hypothyroidism is not unique to radioisotope 131 iodine treatment.
Clinical manifestations of hypothyroidism include: fear of cold, low sweating, dry skin, swelling, tight skin, loss of appetite, bloating, constipation, joint inflexibility, muscle aches, drowsiness and mental depression.
Diagnosis of hypothyroidism: The current diagnosis of hypothyroidism is very accurate and reliable, and can be made by measuring thyroid hormones (T3, T4, TSH) with venous blood.
Treatment of hypothyroidism: In the case of hyperthyroidism treated with isotope 131 iodine, the incidence of permanent hypothyroidism increases at a rate of 1-3% per year, which is not related to the dose of the radioactive drug given, but rather to the patient’s sensitivity to the drug or autoimmune reaction. There is no method to prevent its occurrence, so the key to cure hyperthyroidism is regular checkups for early detection and timely treatment. Alternative treatment is easy, safe, cost-effective and without side effects.