Is radioactive iodine dangerous? Therapeutic treatment of the thyroid gland with radioactive iodine. Treatment with radioactive iodine in Russia

Radioiodine therapy consists in the internal administration of drugs containing radioactive iodine - isotope 131. The doses of drugs are minimal, so the body does not suffer from radiation and does not cause negative consequences.

The drug, getting into the body, begins to disintegrate, as a result, beta and gamma radiation are released. Beta particles do not act on the thyroid gland and are excreted very quickly. And gamma particles are stronger and are able to penetrate into any organs of the patient. By emitting gamma waves using a special device, you can determine the distribution of iodine throughout the body.

Preparations for radioiodine therapy are divided into two types:

1. Gelatin capsules.
2. liquid solution. Allows you to adjust the dosage, but negatively affects the condition of the teeth and oral mucosa.

Radioactive iodine is absorbed only by cells of the thyroid tissue, mainly in the central location. At the site of the dead cells, fibrotic changes are observed, but the remaining peripheral cells are able to secrete a small amount of hormones. Radioactive iodine also has a detrimental effect on metastases, including distant localization.

Radioactive iodine treatment for thyroid cancer

Treatment of thyroid cancer with radioactive iodine is carried out in specialized clinics, since the patient needs to be protected from contact for several days.

How is thyroid radioactive iodine treated?

1. First, the patient is prescribed an examination, according to the results of which an individual dosage of radioactive iodine is selected.
2. If necessary, carry out special training aimed at improving the absorption of iodine.
3. The patient is given a liquid preparation or capsules. The medicine should be washed down with plenty of water.

Typically, treatment and diagnostic rooms are located in close proximity to the wards, but if they are on another floor, then patients who have received a dose of radiation can only use specially designated elevators and stairs.

During treatment, the patient must remain in strict isolation. In each individual case, this period varies from 3 to 21 days, depending on the dosage of the drug. The average hospital stay is 3 to 8 days.

After treatment, the patient is regularly examined to determine whether all thyroid tissue and metastases have been destroyed. The therapeutic effect can be fully assessed 3-4 months after treatment.

Indications and contraindications for treatment

Radioactive iodine is used for medical purposes according to strict indications. Before starting therapy, the patient must undergo a complete examination to confirm the diagnosis.

Indications for use:

• malignant tumors;
• secondary tumors on the background of cancer;
• severe forms of thyrotoxicosis;
• recurrence of thyrotoxicosis;
• inoperable tumors.

The oncologist, referring the patient for treatment, must make sure that he has no contraindications:

• renal and liver failure;
• multinodular goiter, with a volume of more than 40 ml;
• hypersensitivity to the drug;
• thyroiditis that occurs after pregnancy;
• acute stage of gastrointestinal ulcers;
• diabetes mellitus of the decompensated stage;
• behavioral disorders, mental illness;
• aplastic anemia;
• violation of hematopoiesis in the cat's brain;
• HIV, immunodeficiency states.

Radioiodine therapy is contraindicated in childhood, as the thyroid gland of children absorbs an excess dose of radiation, which leads to serious complications. For the same reason, radioactive iodine treatment of the thyroid gland is contraindicated in pregnant and lactating women.

Attention! During pregnancy, radioactive iodine preparations penetrate the thyroid gland of the fetus, causing a threat of radioactive contamination.

What are the pros and cons of radioactive iodine treatment?

Treatment with radioactive iodine has its advantages and disadvantages. They should be considered before prescribing therapy.

Advantages of radioiodine therapy:

• can be used for small tumors, avoiding surgery;
• does not leave scars and scars on the patient's body;
• there is no need for anesthesia;
• radioiodine therapy allows you to get rid of even distant metastases, while affecting only cancer cells;
• there is no damage to the parathyroid glands and cervical nerve.

Flaws:

• a patient who has taken a preparation of the iodine isotope 131 emits radioactive radiation, therefore it is dangerous to others;
• the need for isolation for a period of 3 to 21 days, depending on the dose of drugs;
• all things that the patient has come into contact with are subject to destruction or special processing;
• there are side effects that reduce the quality of life of the patient;
• loss of thyroid function and the need for hormone therapy after treatment.

The gonads are exposed to a certain dose of radiation, so pregnancy can only be planned a year after therapy. The possibility of pregnancy should be consulted with a doctor, since the recovery of the body directly depends on the amount of the drug taken.

Operation or radioactive iodine, what to choose?

Very often the question arises - what to choose surgery or radioiodine therapy? Most often, doubts arise with thyrotoxic goiter, since most patients want to get rid of the problem without surgical intervention.

But with malignant tumors is a necessity. Radioactive iodine is prescribed after surgical removal of a malignant neoplasm. An integrated approach to treatment allows you to completely destroy the cells of the thyroid tissue of the thyroid gland remaining after surgery.

Preparation for therapy

Treatment with radioactive iodine of the thyroid gland requires special preparation. The main condition is the abolition of L-thyroxine and iodine-containing drugs 4-6 weeks before the start of therapy.

After the abolition of hormone therapy, it rises in the body, which contributes to a better capture of iodine isotopes by the thyroid gland. The best effect is achieved if the concentration of thyroid-stimulating hormone does not fall below 30 mU/L.

In some cases, two days before the start of radioiodine therapy, intravenous administration of Thyrogen containing the recombinant human hormone TSH is prescribed. A diet containing a minimum amount of iodine can help to achieve the required level of the hormone, which should begin two weeks before the start of therapy.

Required examinations:

1. Tests for thyroid hormones, TSH, calcitonin.
2. Analyzes for calcium and phosphorus.
3. Ultrasound examination of the neck.
4. Scintigraphy.
5. Radiography of the lungs.
6. Checking the function of external respiration.

If a woman plans to treat her thyroid gland with radioactive iodine, then she needs to make sure that she is not pregnant.

Possible diets and nutrition correction during radioiodine therapy

An oncologist prescribing radioactive iodine treatment should warn him of the importance of an iodine-free diet. A low iodine content in the diet, as well as the abolition of thyroid-stimulating hormones, is required for the preparation of the thyroid gland.

What should be excluded from the diet?

• Seaweed, shrimp, fish and other seafood.
• Sea and iodized salt.
• Butter.
• Smoked meats, marinades.
• Sausages.
• Milk, kefir, cheese.
• Egg yolk.
• Products containing agar-agar.
• Food containing red and orange dye.
• Soy products.
• Greens, green vegetables.
• Legumes.
• Dried fruits.

Attention! You should study the composition of ready-made meals, refuse fast food and eating in public places - you need to cook only at home from permitted products.

What can you eat?

1. Pasta that does not contain eggs.
2. White and brown rice.
3. One serving of cereal per day.
4. No more than 150 g of meat per day.
5. 2-3 servings of river fish per week.
6. Jelly based on gelatin.
7. Egg white.
8. Bitter chocolate.

From vegetables, you can choose zucchini, carrots, potatoes, cucumbers, beets and pumpkins, but in limited quantities. On the day you can eat 2 fruits to choose from: apples, pineapples, peaches, melons. It is permissible to drink natural juices, compotes and fruit drinks.

Treatment after thyroidectomy

Radioactive iodine is performed after a thyroidectomy. This sequence allows you to completely destroy the residual thyroid tissue, regional and distant metastases.

Metastases of thyroid carcinomas pose a serious threat to the patient. The formation of secondary tumors significantly reduces life expectancy.

Radioiodine therapy after removal of the organ can improve survival rates in differentiated cancers.

It is recommended to start cancer treatment with radioactive iodine one month after partial or complete removal of the organ. It has been proven that if radioiodine therapy is performed early after surgery, the likelihood of recurrence and the formation of secondary tumors decreases.

During the course of therapy, precautions are required to protect the people around.

What rules must be followed?

1. It is forbidden to leave the room.
2. Empty the tank twice after using the toilet.
3. Take a shower 1-2 times a day.
4. Hygiene items (brush, comb, razor) rinse with running water.
5. Avoid getting saliva, vomit and feces on the floor.
6. It is impossible to feed animals and birds with leftover food - everything is disposed of in special containers.
7. Hygiene items and clothes remain in the room after discharge for disposal.
8. Drink enough clean water.

Attention! Within 1-1.5 months after treatment, it is necessary to avoid contact with pregnant women, children and people with reduced immunity - small doses of radiation continue to be released with sweat and air flow.

After discharge from the hospital, you can start working in 3-4 weeks. But for another two months, it is necessary to limit physical activity, as well as refuse to visit the pool and public baths.

Consequences of radioactive iodine treatment

Radioiodine therapy can cause complications.

The first effects of radioactive iodine treatment of the thyroid gland appear within 7-10 days after taking the medication, these include:

• burning and sore throat;
• nausea, vomiting;
• stool disorders;
• pain in the abdomen;
• dry mouth, thirst;
• exacerbation of chronic pathologies;
• slight increase in temperature;
• severe weakness;
• inflammation of the salivary glands;
• allergic manifestations.

Long-term side effects for radioiodine therapy are not typical. Iodine preparations are quickly excreted from the body, without exerting a carcinogenic effect. Even if a slight effect of radiation is exerted on the sex glands, then after 1-1.5 years you can start planning a pregnancy.

Where is radioiodine therapy treated in Russia, and what is the cost of therapy?

There are few clinics in Russia where cancer treatment with radioactive iodine is practiced. This is explained by the fact that the radiotherapy department must be specially equipped, and this is quite expensive. For this reason, this type of therapy is not available in most clinics.

Where do they undergo therapy in Russia?

1. Centers for Nuclear Medicine in Kazan and Krasnoyarsk.
2. FGBU "RNTSRR" Moscow.
3. Arkhangelsk Medical Center named after N.A. Semashko.
4. "MRNC" them. A.F. Tsyba, Obninsk.
5. City hospital No. 13, Nizhny Novgorod.
6. Omsk regional hospital.

On average, the price for a course varies from 70,000 to 150,000 rubles. The cost of therapy depends on the dosage of the drug, living conditions and the length of stay in the hospital. The final prices must be obtained directly from the clinic.

Attention! You can get a quota under the CHI policy - get treatment for free. To do this, you need to collect a package of necessary documents and wait for the decision of the medical commission.

Radioactive iodine (iodine isotope I-131) is a radiopharmaceutical that is highly effective in the non-surgical treatment of thyroid pathologies.

Despite the relative safety of radioactive iodine treatment, the consequences can still manifest themselves from a very unsightly side.

So that their occurrence does not become an obstacle to healing, it is necessary to consider all possible scenarios for the development of events.

The main therapeutic effect of this method of treatment is due to the destruction (ideally - complete) of the damaged areas of the thyroid gland.

After the start of the course, positive dynamics in the course of the disease begins to appear after two to three months.

During this time, the organs of the endocrine system adapt to the new conditions of existence, and gradually normalize the mechanism for performing their functions.

The final result is a decrease in the production of thyroid hormones to normal levels, i.e. recovery.

In case of repeated manifestation of the pathology (relapse), it is possible to prescribe an additional course of radioiodine I-131.

The main indications for the appointment of radioactive iodine therapy are conditions in which an excessive amount of thyroid hormones is produced or malignant tumors are formed:

• hyperthyroidism - increased hormonal activity of the thyroid gland, accompanied by the formation of local nodular neoplasms;
• thyrotoxicosis - a complication of hyperthyroidism that occurs due to prolonged intoxication with an excess of secreted hormones;
• various types of oncological diseases (cancer) of the thyroid gland - the degeneration of the affected tissues of the organ, characterized by the appearance of malignant tumors against the background of the current inflammatory process.

If during the examination distant metastases were detected, the cells of which accumulate iodine, then radioactive therapy is carried out only after the surgical (surgical) removal of the gland itself. Timely intervention followed by treatment with the I-131 isotope in most cases leads to a complete cure.

toxic goiter

Radioiodine therapy is highly effective as a replacement for surgery in pathologies such as Graves' goiter, the so-called. Graves' disease (diffuse toxic goiter) and functional autonomy of the thyroid gland (nodular toxic goiter).

The practice of using this method of treatment is especially popular in patients for whom there is a high probability of postoperative complications or the operation is associated with a risk to life.

Radioiodine therapy is strictly contraindicated for pregnant and lactating women. During these periods, exposure to iodine I-131 can adversely affect the process of fetal formation and its further development.

Treatment with radioactive iodine of the thyroid gland - consequences

Radioiodine therapy often causes suppression of thyroid function, which may lead to the development of hypothyroidism. The lack of hormones during this period is compensated by medications.

After the restoration of normal hormonal levels, the further life of recovered people is not limited to any special framework and conditions (excluding cases of complete removal of the organ).

Extensive studies of the method have shown the likelihood of certain negative consequences:

• deterministic (non-stochastic) effects - accompanied by acute symptoms;
• remote (stochastic) effects - proceed imperceptibly for a person and come to light only after some time.

Good health immediately after the end of the course is not a guarantee of the absence of side effects of radioactive iodine.

Thyroid cancer has been cured. in 90% of cases it is completely cured with adequate therapy.

You can familiarize yourself with the main methods of treating the thyroid gland.

Medullary thyroid cancer has a poor prognosis, but 5- and 10-year survival rates are high. You can read more about this disease.

Deterministic Effects

Most of those who have undergone this type of therapy do not notice a pronounced negative reaction. Sudden painful symptoms are rare and, as a rule, quickly pass without the use of drugs.

In some cases, after the procedure, the following reactions may occur:

• tightness and discomfort in the neck;
• pain when swallowing;
• allergic manifestations - rash, itching, fever, etc.;
• inflammation of the salivary and lacrimal glands (resorption of lollipops helps to restore the patency of the channels);
• nausea, vomiting, disgust in food;
• exacerbation of gastritis, ulcers (the condition is stopped by special drugs);
• amenorrhea (absence of menstrual flow) and dysmenorrhea (periodic pain during the cycle) in women;
• oligospermia (decrease in the amount of semen released) in men (potency will not be affected);
• post-radiation cystitis (corrected by increased stimulation of urination with diuretics);
• pancytopenia, aplasia and hypoplasia - a violation of the formation and development of tissues, deterioration of the component composition of the blood (pass on their own).

When working with patients with thyrotoxicosis, there is a high probability of an exacerbation of the disease within one to two weeks after the iodine radiotherapy procedure. During this period, antithyroid drugs are additionally prescribed to prevent further intoxication.

Long-term effects

Experience in the use of radioactive iodine I-131 for medicinal purposes has more than fifty years.

During this time, no carcinogenic effect on humans has been detected: in the place of destroyed thyroid cells, connective tissue is formed, which reduces the risk of developing malignant neoplasms to an absolute minimum.

Currently, instead of the original liquid solution, a capsule form of radioactive iodine is used, the irradiation radius of which is from 0.5 to 2 mm. This allows you to almost completely isolate the body as a whole from harmful radiation.

Mutagenic and teratogenic effects have also not been confirmed. Radioactive iodine has a fairly short half-life and does not accumulate in the body. After treatment, the genetic material and reproductive ability are preserved, so you can plan a pregnancy in a year. As a rule, this time is enough to restore all damaged systems, which will allow the production of germ cells suitable for fertilization to resume.

If you neglect these warnings, then there is a high probability of conceiving offspring with genetic abnormalities. With a properly planned pregnancy, radioiodine therapy will not affect either the health or the life of the child.

The possibility of conception must be discussed with a specialist, because. its safety depends on many factors, and the permitted period is set individually in each individual case.

Treatment with radioactive iodine is used mainly in the USA (use is limited in Russia and most European countries). Liquid or capsules containing radioactive iodine are taken orally (occasionally intravenous administration of the drug is used).

In Europe and Russia, treatment is carried out in hospital departments specially equipped with a radiation protection system. In the US, treatment is done on an outpatient basis, which makes this type of therapy economically more profitable than surgery.

The mechanism of action of radioactive iodine

Once in the body, iodine is selectively accumulated by thyroid cells, leading to their death and replacement by connective tissue. Relatively high concentrations of radioisotopes of iodine are also found in the salivary and mammary glands and the mucous membrane of the gastrointestinal tract.

Features of the action of radioactive iodine:

• Uneven distribution of radioactive iodine in the body: radioactive iodine is selectively absorbed by the central areas of the thyroid tissue and destroys them, while the peripheral zones retain the ability to produce hormones.
• The absence of a pronounced side effect on the surrounding tissues: the main part of the isotope radiation is represented by beta particles penetrating into the tissue at a distance not exceeding 2.2 mm.

Treatment with radioactive iodine

Features of the treatment:

1. A few days before taking radioactive iodine, thyreostatic drugs are canceled, as they reduce the therapeutic effect of radioactive iodine.
2. In women of childbearing age, it is necessary to conduct a rapid test to diagnose pregnancy in order to rule out the possibility of prescribing radioactive iodine if the result is positive.
3. To prevent worsening of the course of endocrine ophthalmopathy, before the appointment of radioactive iodine, glucocorticoid therapy and / or external irradiation of the orbits is recommended.
4. The calculation of the administered dose is made taking into account the volume of the entire thyroid gland (the volume of the organ is determined using ultrasound).
5. Treatment of concomitant pathology, vitamin therapy is carried out.
6. For breastfeeding women, it is advisable to either stop breastfeeding or postpone radioactive iodine treatment for some time.

Duration of radioactive iodine therapy

Usually, the phenomena of thyrotoxicosis are eliminated, and laboratory parameters and data from radionuclide studies are normalized 2-3 months after treatment. Sometimes repeated courses of therapy are required.

For timely diagnosis of planned hypothyroidism, it is necessary to determine the level of T4 and TSH every 3-4 months during the first year after treatment. Hypothyroidism that develops within the first 6 months after radioactive iodine therapy can sometimes be temporary.

Advantages of the method:

• High efficiency (lasting effect is observed in 90-99% of patients).
• Safety (?).

The question mark is not random. To date, disputes between experts on this issue have not subsided.

On the one hand, it is known that radioactive iodine has a short half-life (the time during which its activity decreases by 2 times) - 8 days, therefore, it cannot lead to long-term environmental pollution. We have already spoken about the low penetrating power of beta particles. Therefore, these patients cannot pose a serious danger to others as sources of harmful radiation. Radioactive iodine is excreted mainly in the urine. In specialized departments, subject to basic hygiene rules, radiation will not spread beyond the sewerage system.

However, the Chernobyl tragedy is still too fresh in my memory, after which, 5-10 years later, there was a sharp increase in the incidence of thyroid cancer among children, aggravated by the presence of iodine deficiency in the disaster area and in neighboring regions. The penetration of radioactive isotopes into the body of children is especially dangerous, since their thyroid gland is smaller than that of adults, and also has greater radiosensitivity (an infant's gland absorbs 20-25 times more radioactive iodine than an adult gland). Let's not forget that radioactive iodine is capable, albeit in a small amount, of emitting gamma radiation, the penetrating power of which is very high, which causes its greater damaging effect on tissues.

Despite this, a number of recent studies cast doubt on the carcinogenic effect (that is, the ability to cause malignant processes) of radioactive iodine. Indeed, the outcome of radioactive iodine treatment is the replacement of functioning tissue with thyroid connective tissue, after which there are practically no conditions and places left for the development of a cancerous tumor. In addition, it is worth recalling that in Chernobyl it was about massive environmental pollution with many radioactive isotopes, including radioactive iodine, the doses of which many times exceeded the dosages used for therapeutic purposes.

• It does not require prior preparation with thyreostatics before euthyroidism.
• If necessary, the course of treatment can be repeated.
• There are no restrictions for elderly patients and in relation to the presence of any concomitant disease.
• Hospitalization is only for a few days.

Indications for radioactive iodine treatment

Indications:

1. The age of patients is over 40-45 years. Currently, there is a tendency to revise this indication (including in our country) and remove these restrictions, because most patients with diffuse toxic goiter are women aged 20 to 40 years (in the United States, for example, radioactive iodine therapy is considered treatment of first choice in patients with thyrotoxicosis over 28 years of age).
2. Return of signs of thyrotoxicosis after medical and / or surgical treatment.
3. Thyrotoxicosis revealed for the first time in the development of complications while taking thyreostatics.
4. Severe and complicated forms of thyrotoxicosis.
5. The patient's inability to comply with the conservative therapy regimen or refusal of the operation.
6. The presence of concomitant pathology, which can serve as an obstacle to the operation.

Note. Radioactive iodine is also used in the treatment of thyroid cancer, both in adults and children.

Contraindications to radioactive iodine treatment

Contraindications:

• Pregnancy and breastfeeding. Radioactive iodine, entering the body of the fetus or newborn through the placenta or with breast milk, will accumulate in the thyroid gland, leading to the development of congenital hypothyroidism.
• Large goiter (more than 40 ml).

In this case, to block the function of the thyroid gland, too much dose of radioactive iodine will be required.

Complications of radioactive iodine treatment

Complications:

• Iodine-induced thyrotoxicosis (the next symptoms occur in the first hours after taking radioactive iodine, they do not last long and leave no consequences, and the later ones develop on the 5-6th day and are usually more severe and prolonged).
• thyrotoxic crisis.
• Radiation thyroiditis (2-6% of cases).
• Retrosternal goiter.
• Intolerance to iodine preparations.

The need for contraceptives in the treatment of radioactive iodine

In order to avoid pregnancy in the first 4 months after treatment with radioactive iodine, it is advisable for women to use effective contraceptives (for example, hormonal drugs).

M. Veldanova, A. Skalny

"Treatment of diffuse toxic goiter with radioactive iodine" - section

All chemical elements form isotopes with unstable nuclei, which emit α-particles, β-particles or γ-rays during their half-life. Iodine has 37 types of nuclei with the same charge, but differing in the number of neutrons that determine the mass of the nucleus and the atom. The charge of all isotopes of iodine (I) is 53. When they mean an isotope with a certain number of neutrons, write this number next to the symbol, through a dash. In medical practice, I-124, I-131, I-123 are used. The normal isotope of iodine (not radioactive) is I-127.

The number of neutrons serves as an indicator for various diagnostic and therapeutic procedures. Radioiodine therapy is based on the varying half-lives of the radioactive isotopes of iodine. For example, an element with 123 neutrons decays in 13 hours, with 124 - in 4 days, and I-131 will have a radioactive effect after 8 days. More often, I-131 is used, during the decay of which γ-rays, inert xenon and β-particles are formed.

The effect of radioactive iodine in the treatment

Iodine therapy is prescribed after the removal of the thyroid gland completely. With partial removal or conservative treatment, this method does not make sense to use. The follicles of the thyroid gland receive iodides from the tissue fluid that surrounds them. Iodides enter the tissue fluid by diffusion or by active transport from the blood. During iodine starvation, secretory cells begin to actively capture radioactive iodine, and degenerate cancer cells do this much more intensively.

β-particles, released during half-life, kill cancer cells.

The striking ability of β-particles acts at a distance of 600 - 2000 nm, which is quite enough to destroy only the cellular elements of malignant cells, and not neighboring tissues.

The main goal of radioiodine therapy is the final removal of all remnants of the thyroid gland, because even the most skillful operation leaves behind these remnants. Moreover, in the practice of surgeons, it has already become customary to leave several gland cells around the parathyroid glands for their normal operation, as well as around the recurrent nerve that innervates the vocal cords. The destruction of the iodine isotope occurs not only in the residual tissues of the thyroid gland, but also metastasis in cancerous tumors, which makes it easier to monitor the concentration of thyroglobulin.

γ-rays do not have a therapeutic effect, but they are successfully used in the diagnosis of diseases. The γ-camera built into the scanner helps to determine the localization of radioactive iodine, which serves as a signal for the recognition of cancerous metastases. The accumulation of the isotope occurs on the surface of the front of the neck (in the place of the former thyroid gland), in the salivary glands, along the entire length of the digestive system, in the bladder. Few, but still there are iodine uptake receptors in the mammary glands. Scanning reveals metastases in trimmed and nearby organs. Most often they are found in the cervical lymph nodes, bones, lungs and tissues of the mediastinum.

Treatment prescriptions for radioactive isotopes

Radioiodine therapy is indicated for use in two cases:

1. If the state of a hypertrophied gland is detected in the form of a toxic goiter (nodular or diffuse). The state of diffuse goiter is characterized by the production of thyroid hormones by the entire secretory tissue of the gland. In nodular goiter, only the nodular tissue secretes hormones. The tasks of introducing radioactive iodine are reduced to the inhibition of the functionality of hypertrophied areas, since the radiation of β-particles destroys precisely those places that are prone to thyrotoxicosis. At the end of the procedure, either the normal function of the gland is restored, or hypothyroidism develops, which is easily normalized when using an analogue of the hormone thyroxine - T4 (L-form).
2. If a malignant neoplasm of the thyroid gland (papillary or follicular cancer) is found, the surgeon determines the degree of risk. In accordance with this, risk groups are distinguished according to the level of tumor progress and possible distant localization of metastases, as well as the need for radioactive iodine treatment.
3. The low-risk group includes patients with a small tumor, not exceeding 2 cm and located in the outline of the thyroid gland. No metastases were found in neighboring organs and tissues (especially in the lymph nodes). Such patients do not need to inject radioactive iodine.
4. Patients with an average risk have a tumor larger than 2 cm, but not exceeding 3 cm. If an unfavorable prognosis develops and the capsule in the thyroid gland germinates, a dose of radioactive iodine of 30-100 mCi is prescribed.
5. The high-risk group has a pronounced aggressive pattern of cancer growth. There is germination in neighboring tissues and organs, lymph nodes, there may be distant metastases. Such patients require treatment with a radioactive isotope greater than 100 millicuries.

Radioiodine Administration Procedure

The radioactive isotope of iodine (I-131) is synthesized artificially. It is taken in the form of gelatin capsules (liquid) orally. Capsules or liquid are odorless and tasteless, swallowed only with a glass of water. After taking the liquid, it is recommended to immediately rinse your mouth with water and swallow it without spitting it out.

In the presence of dentures, it is better to remove them for a while before using liquid iodine.

You can’t eat for two hours, you can (even need) to take a plentiful drink of water or juice. Iodine-131, not absorbed by the thyroid follicles, is excreted in the urine, so urination should occur every hour with the control of the content of the isotope in the urine. Medicines for the thyroid gland are taken no earlier than 2 days later. It is better if the patient's contacts with other people at this time are strictly limited.

Before the procedure, the doctor must analyze the medications taken and stop them at different times: some of them - a week, others at least 4 days before the procedure. If a woman is of childbearing age, then pregnancy planning will have to be postponed for a period determined by the doctor. Previous surgery requires a test for the presence or absence of tissue capable of absorbing iodine-131. 14 days before the start of the introduction of radioactive iodine, a special diet is prescribed, in which the normal isotope of iodine-127 must be completely eliminated from the body. The list of products for the effective removal of iodine will be prompted by the attending physician.

Treatment of cancerous tumors with radioactive iodine

If the iodine-free diet is correctly observed and the period of restrictions on the intake of hormonal drugs is observed, the thyroid cells are completely cleared of iodine residues. With the introduction of radioactive iodine against the background of iodine starvation, cells tend to capture any isotope of iodine and are affected by β-particles. The more actively cells absorb a radioactive isotope, the more they are affected by it. The dose of irradiation of thyroid follicles that capture iodine is several tens of times greater than the effect of a radioactive element on surrounding tissues and organs.

French experts have calculated that almost 90% of patients with lung metastases survived after treatment with a radioactive isotope. Survival within ten years after the application of the procedure was more than 90%. And these are patients with the last (IVc) stage of a terrible disease.

Of course, the described procedure is not a panacea, because complications after its use are not excluded.

First of all, it is sialadenitis (inflammation of the salivary glands), accompanied by swelling, soreness. This disease develops in response to the introduction of iodine and the absence of thyroid cells capable of capturing it. Then the salivary gland has to take over this function. It should be noted that sialadenitis progresses only at high radiation doses (above 80 mCi).

There are cases of violation of the reproductive function of the reproductive system, but with repeated exposures, the total dose of which exceeds 500 mCi.

Treatment after thyroidectomy

Often, cancer patients are prescribed iodine therapy after removal of the thyroid gland. The objective of this procedure is the final defeat of cancer cells remaining after the operation, not only in the thyroid gland, but also in the blood.

After taking the drug, the patient is placed in a single room, which is equipped in accordance with the specifics.

Medical personnel are limited to contact for up to five days. At this time, visitors should not be allowed into the ward, especially pregnant women and children, in order to protect them from the flow of radiation particles. Urine and saliva of the patient are considered radioactive and are subject to special disposal.

Pros and cons of radioactive iodine treatment

The described procedure cannot be called completely “harmless”. Thus, during the action of a radioactive isotope, temporary phenomena are noted in the form of painful sensations in the region of the salivary glands, tongue, and front of the neck. The mouth is dry, itchy in the throat. The patient is sick, there is frequent urge to vomit, swelling, food becomes not tasty. In addition, old chronic diseases become aggravated, the patient becomes lethargic, gets tired quickly, and is prone to depression.

Despite the negative aspects of treatment, the use of radioactive iodine is increasingly used in the treatment of thyroid gland in clinics.

The positive reasons for this pattern are:

• there is no surgical intervention with cosmetic consequences;
• general anesthesia is not required;
• the relative cheapness of European clinics compared to operations with a high quality of service and scanning equipment.

Danger of radiation on contact

It should be remembered that the benefit provided in the process of using radiation is obvious to the patient himself. For the people around him, radiation can play a cruel joke. Not to mention the visitors of the patient, let us mention that medical workers provide care only when necessary and, of course, in protective clothing and gloves.

After discharge, you should not be in contact with a person closer than 1 meter, and with a long conversation, you should move 2 meters away. In the same bed, even after discharge, it is not recommended to sleep in the same bed with another person for 3 days. Sexual contacts and being near a pregnant woman are strictly prohibited within a week from the date of discharge, which occurs five days after the procedure.

How to behave after irradiation with an isotope of iodine?

Eight days after discharge, children should be kept away from themselves, especially contact. After using the bathroom or toilet, flush three times with water. Hands are washed thoroughly with soap.

It is better for men to sit on the toilet when urinating to prevent splashing of radiation urine. Breastfeeding should be discontinued if the patient is a nursing mother. The clothes in which the patient was on treatment are placed in a bag and washed separately a month or two after discharge. Personal belongings are removed from common areas and storage. In case of emergency admission to the hospital, it is necessary to warn the medical staff about the recent course of iodine-131 irradiation.

Iodine is a chemical that was discovered back in 1811 by the French chemist Bernard Courtois when mixing seaweed ash and sulfuric acid. A couple of years later, his compatriot, the chemist Gay-Lussac, studied the resulting substance in more detail and proposed the name "iodine". Translated from Greek, "iodine" means "violet", in connection with the appearance of a purple color when it is burned.

Iodine and the thyroid gland

The main function of the thyroid gland is the production of the hormone thyroxine. Thyroxine is a very important hormone in

our body, participating in all metabolic processes, supporting the work of muscles, the brain and all internal organs. Thyroxin can be compared to fuel for the body, like gasoline for a car. Thyroxin is formed in the cells of the thyroid gland with the participation of iodine and the amino acid tyrosine. There are four iodine atoms in the thyroxine molecule. The peculiarity of thyroid cells is that they have the ability to capture iodine from the bloodstream and transport it into the follicle (structural unit of the thyroid gland). Already inside the follicle, under the action of special enzymes, thyroxine is formed from the amino acid tyrosine and four iodine atoms. Treatment with radioactive iodine is based on the ability of thyroid cells to capture iodine.

What is radioactive iodine

Every chemical element has one or more isotopes whose nuclei are unstable and when radioactive decay produces electromagnetic radiation, which can be alpha, beta or gamma. Isotopes are called chemical elements that have the same number of protons, but a different number of neutrons, while isotopes differ from each other in physical properties. There are 37 known isotopes of iodine. I-127 is stable, and the most commonly used isotopes of radioactive iodine in medicine are I-131, I-123, I-124. Iodine is usually denoted by the letter I. When designating an isotope, next to the letter I indicate the number of protons and neutrons in its atom. It is important to note that the number of protons in an iodine atom is constant - there are always 53 of them. If we are talking about the isotope of radioactive iodine 131 (I-131), this means that its atom contains 53 protons and 78 neutrons (their sum is 131, which is indicated in the numerical part of the isotope designation). If iodine is 123, then its atom also has 53 protons, but already 70 neutrons, etc. It is the number of neutrons that determines the properties of the isotope and, as a result, various diagnostic and therapeutic purposes. An important characteristic of radioactive iodine is its half-life. So, for example, for I-131 this period is 8 days, for I-124 it is 4 days, and for I-123 it is 13 hours. The half-life is the period during which the activity of iodine falls by half. The decay of radioactive iodine (I-131) produces xenon, beta particles and gamma radiation.

The principle of action of radioactive iodine in the treatment of thyroid cancer

Radioactive iodine treatment should only be given to patients who have had their thyroid completely removed.

If part or half of the thyroid gland is removed, radioactive iodine treatment is pointless. Thyroid cells have the ability to capture iodine from the blood. It is important to note that thyroid cancer cells (papillary, follicular) are less active, but can also capture iodine. Tumor cells, when exposed to radioactive iodine, die under the influence of beta radiation. The penetrating power of beta radiation is from 0.6 to 2 mm, which makes it possible to destroy cells in which iodine has accumulated, but there is no damage to surrounding tissues. One of the objectives of radioactive iodine treatment is the destruction of residual thyroid tissue, which is present even after a perfectly performed operation. It is not uncommon for an endocrinologist surgeon to deliberately leave a small amount of healthy thyroid tissue in both the recurrent laryngeal nerve area (for voice preservation) and the parathyroid gland area (for their normal functioning). Thus, radioactive iodine destroys not only possible cancer metastases, but also the residual tissue of the thyroid gland, which allows more accurate control of thyroglobulin levels in the postoperative period. Gamma radiation, which is formed during the decay of radioactive iodine, freely penetrates through all tissues of the body and can be recorded using a gamma camera. Gamma radiation does not carry a therapeutic effect, but is used for diagnosis. The result of the scan indicates in which part of the body radioactive iodine has accumulated, which may indicate the presence of thyroid cancer metastases. As a rule, when scanning the whole body after radioiodine therapy, the accumulation of the drug is detected on the anterior surface, in the place where the thyroid gland was. Also, the accumulation of iodine occurs in the salivary glands, along the digestive tract and in the bladder. Sometimes iodine can accumulate in the mammary glands, which have small amounts of iodine receptors.

When scanning the whole body, it is important to check for distant metastases. Most often, metastases are detected in the lymph nodes of the neck and mediastinum, in the lungs and even bones.

Indications for radioactive iodine treatment

According to international and Russian clinical guidelines, there are three risk groups among patients with thyroid cancer. Depending on the risk group, the endocrinologist surgeon determines the need for radioactive iodine treatment. The risk group is determined by the probability of the presence of distant metastases and the progression of the tumor process.

Low risk group.

Patients with a tumor that does not exceed 1–2 cm in size and does not extend beyond the thyroid gland can be classified as low-risk. There are no metastases in the lymph nodes of the neck and other organs. Low-risk patients are not prescribed radioactive iodine therapy.

Medium risk group.

The medium-risk group includes patients with a thyroid tumor of more than 2-3 cm in diameter, with germination of the gland capsule and unfavorable histological variants. Patients in this group are usually prescribed radioactive iodine therapy. In this case, the dosage can be from 30 to 100 millicuries (mCi).

High risk group.

This group includes patients with aggressive growth of thyroid cancer, when there is germination in the surrounding tissues (muscles, blood vessels, trachea), lymph nodes of the neck and there are distant metastases. Patients in this group are required to be treated with radioactive iodine at a dose of 100 mCi or more.

Increasing TSH TSH is a thyroid-stimulating hormone that is produced by the pituitary gland and normally regulates the functioning of the thyroid gland. One of the important properties of TSH is to stimulate the growth of thyroid cells. It is known that TSH also stimulates the growth of thyroid tumor cells. It is important to note that thyroid cancer cells are less able to take up iodine than healthy thyroid cells. However, with a high level of TSH, thyroid tumor cells are better able to capture radioactive iodine, and therefore are better destroyed. Two methods are used to increase TSH levels: stopping L-thyroxine for four weeks or administering recombinant TSH (an artificially created preparation of human TSH).

Stop taking thyroxine

To increase the TSH level before treatment with radioactive iodine, patients stop taking thyroxine for a period of three to four weeks. In this case, the TSH level should become above 30 mU / l. In fact, the higher the TSH, the better the thyroid tumor cells will be destroyed. In addition to stimulating thyroid cancer cells, the abolition of thyroxine intake leads, so to speak, to "starvation" of tumor cells for iodine. After all, we must not forget that there are four iodine atoms in thyroxine, and when taking a pill, tumor cells take on some of this iodine. If within three to four weeks iodine does not enter the body, then the tumor cells, when radioactive iodine is harmful to them, begin to actively capture it. As it was written earlier, after radioactive iodine enters the cell, it is destroyed.

The main disadvantage of thyroxine withdrawal is the occurrence of hypothyroidism. Hypothyroidism is a lack of thyroid hormones that can be accompanied by various symptoms. It is important to note that the manifestation of hypothyroidism against the background of the withdrawal of thyroxin before the treatment with radioactive iodine manifests itself differently in all patients. There are patients who practically do not feel the withdrawal of thyroxin, at the same time, there are patients who already two weeks after the withdrawal of the drug complain of sudden weakness, apathy and swelling of the face or other manifestations of hypothyroidism.

Symptoms of hypothyroidism:

Leather: may be dry, pale, and cold to the touch.

Hair: become brittle and fall out.

Gastrointestinal tract: patients feel a decrease in appetite, taste, constipation may occur.

Respiratory system: some patients may experience diaphragmatic weakness and, as a result, breathing problems (shortness of breath, weakness of breathing).

Nervous system: memory impairment and decreased attention, the appearance of headaches, the development of depressive states is possible.

The cardiovascular system: the pulse becomes rare (bradycardia), mild arterial hypertension (increased blood pressure) may occur, and atherosclerosis may progress in some patients.

Hematopoietic system: mild anemia (a decrease in the level of hemoglobin in the blood), an increase in bleeding time with cuts and injuries is possible.

Muscular system: with hypothyroidism, patients feel weakness in the muscles, physical activity is difficult to tolerate. It is important to note that after the start of taking thyroxin, the symptoms that arose against the background of hypothyroidism disappear and do not reappear with the right dosage.

The use of recombinant TSH

Recombinant TSH is TSH in the form of a pharmacological preparation for intravenous administration, which was synthesized artificially. The use of recombinant TSH is the second way to increase the level of TSH in the patient's body before radioactive iodine treatment. Unfortunately, recombinant TSH is not registered in Russia and cannot be officially used to prepare for radioactive iodine treatment. The closest countries where you can officially get recombinant TSH are Ukraine, Estonia, Finland.

Diet low in iodine (iodine-free diet)

All patients are prescribed an iodine-free diet in preparation for radioactive iodine treatment. The idea of ​​an iodine-free diet is to avoid iodized salt and foods containing iodine from the daily diet as much as possible. The daily intake of iodine should be kept to a minimum, not exceeding 50 micrograms per day. The duration of the diet is one to three weeks before radioactive iodine therapy and one to two days after treatment.

What is the effect of "starvation" and why do I need an iodine-free diet

When recommending radioactive iodine treatment, the specialist doctor understands that the patient is at risk of having thyroid cancer metastases (in the lymph nodes of the neck, lungs, liver, bones). It is important not to forget that thyroid cancer cells have lost the properties of healthy cells, but in the vast majority they have not lost the ability to capture iodine.

Imagine a patient with thyroid cancer metastases, for example, to the lungs. The patient limits himself in iodine intake for one to three weeks (an obligatory step in preparing for iodine treatment is the abolition of L-thyroxine), while the entire body receives less iodine. Most importantly, the thyroid cancer cells that reside in the lungs are also starving for iodine.

Preparing for Radioiodine Therapy

The day comes when you receive a dose of radioactive iodine, and the thyroid cancer cells “do not understand” whether they received radioactive iodine or ordinary. Against the background of prolonged “starvation”, they begin to capture radioactive iodine from the blood with greater force. The more actively cancer cells capture radioactive iodine, the more destructive it acts on them. Against the background of a properly maintained iodine-free diet and the abolition of thyroxin, the effectiveness of radioactive iodine treatment will be maximum.

Treatment with radioactive iodine

After the preparation - the abolition of L-thyroxine (or the introduction of recombinant TSH) and an iodine-free diet - determine the required dose of iodine and proceed directly to treatment. The dosage of radioactive iodine is determined by radiologists. There are several commonly used doses of radioactive iodine: 30, 100 and 150 mCi (mCi). The choice of one or another dosage is carried out depending on the prevalence and aggressiveness of thyroid cancer. For example, if the tumor has grown only in the capsule of the thyroid gland, the dose of iodine will be less than if the cancer has spread to the lymph nodes of the neck, lungs, or bones. After selecting the dose of radioactive iodine under the supervision of specialists, the patient takes the drug. Radioactive iodine comes in two forms: a capsule or a liquid. The therapeutic and diagnostic effect of the capsule or liquid form is not fundamentally different.

It is important to note that the main routes of excretion of radioactive iodine from the human body are the urinary system, gastrointestinal tract, salivary and sweat glands. The patient will be given detailed advice on nutrition, fluid intake and personal hygiene while in the clinic and upon returning home. After receiving radioactive iodine, radiation is emitted from the patient, which can be dangerous to some extent for the people around. In this regard, all patients who have received a dose of radioactive iodine are explained in detail how to behave with others. The main recommendation is to avoid contact with children and pregnant women for at least a week after receiving a dose of radioactive iodine. Very often I hear from patients that the period of isolation from other people after treatment with radioactive iodine should reach a month or more. This information is not true. I will cite data prepared in 2011 by the American Thyroid Association (ATA) in conjunction with the International Commission on Radiation Protection (ICRP). The maximum isolation period (being in the same bed with pregnant women, newborns or children) of 21 days applies to patients who received a dose of radioactive iodine equal to 200 mCi. At the same time, the periods of isolation in the most common situations that patients face when they are discharged from the clinic after radioactive iodine treatment, such as going to work, talking with friends, walking in crowded places, do not exceed one day. Patients who follow these recommendations and the basics of personal hygiene are not dangerous to others and can absolutely calmly be in society and lead a normal life.

Regarding the timing of planning children after radioactive iodine treatment, there are the following recommendations: for men - after 2-3 months, for women - after 6-12 months. I advise all patients who have undergone radioactive iodine treatment to have documents from the clinic with them when crossing borders or checkpoints equipped with radiation detection devices for two to three months. During these periods, you, of course, are not dangerous to anyone, but modern devices can detect radiation from you and give a signal to the appropriate services about this. Most often, such situations occur at checkpoints at airports, so plan your time taking into account possible delays.

The effect of radioactive iodine on the body

It is important to understand that radioactive iodine is not a vitamin complex, and its appointment should be carried out strictly according to

indications, according to international and Russian clinical guidelines. Before the course of treatment with radioactive iodine, the patient should be familiar with the possible adverse effects that may occur immediately or some time after taking the radiopharmaceutical. The development of undesirable symptoms directly depends on the dosage of the received radioiodine. Patients can be divided into three groups, depending on the frequency and severity of side effects. The first group may include patients who have had a diagnostic scan with low doses of radioiodine. The second group, the largest, includes patients who underwent radioiodine therapy after surgery and received an iodine dose of 30 to 200 mCi. The third group of patients, fortunately not numerous, includes those who repeatedly received high doses of radioactive iodine.

In diagnostic scanning, the dose of radioactive iodine does not exceed 1–5 mCi, and in such cases, adverse effects are extremely rare. When conducting radioactive iodine treatment, depending on the type of cancer, spread beyond the thyroid gland and the size of the tumor, the dose can vary from 30 to 200 mCi. In such cases, side effects are possible, and their likelihood is higher, the higher the dose of radioactive iodine received. The most common adverse symptoms after receiving a therapeutic dose of radioactive iodine are as follows. Swelling and pain. In some patients, after receiving a dose of radioactive iodine, swelling occurs in the neck (in the area where the thyroid gland was). This phenomenon can be explained by the destruction of the residual tissue of the thyroid gland. At the same time, the surrounding tissues react (muscles, lymph nodes, fatty tissue), which are involved in the edema, increasing in size. The swelling usually goes away after a few days and does not require treatment. With severe discomfort, the patient can be prescribed anti-inflammatory drugs with a good therapeutic effect. Nausea and vomiting. Nausea and vomiting may occur hours or days after receiving a therapeutic dose of radioactive iodine. These symptoms may be more active in patients with chronic diseases of the gastrointestinal tract. As a rule, in a clinic where radioactive iodine treatment is carried out, they talk about the correct water regimen and, if necessary, prescribe drugs that protect the stomach and intestines (antacids).

Inflammation of the salivary glands (sialadenitis).

A person has three paired (right and left) salivary glands. The largest is the parotid salivary gland, which is located on the lateral surface of the face - just below and anterior to the ear. The other two are the submandibular and sublingual glands. The resulting therapeutic dose of radioactive iodine partially accumulates in the salivary glands and, as a result, causes their inflammation. The parotid salivary gland is most sensitive to iodine. Sialoadenitis occurs in almost 30% of patients treated with radioactive iodine. The unpleasant thing is that sialoadenitis can occur both a day and a few months after receiving radioactive iodine. A manifestation of sialoadenitis is pain and swelling in the area of ​​the salivary gland, fever, and a decrease in the amount of saliva. The pain usually gets worse with eating.

Treatment of sialadenitis is not an easy task. First of all, it is important to inform your doctor about the occurrence of problems with the salivary glands. Your doctor will definitely recommend who to contact for help.

Depending on the situation, different regimens for the treatment of sialadenitis can be used. The main recommendations when it occurs are as follows:

1. The use of sour sweets, chewing gums, that is, means that enhance salivation. This will lead to a more active removal of radioactive iodine from the salivary glands, which should reduce the likelihood of their further inflammation.

2. Consumption of a large amount of liquid. When a large amount of liquid is received, more saliva will be produced, with the current of which radioactive iodine will be better excreted.

3. The use of anti-inflammatory drugs. Anti-inflammatory drugs reduce swelling and thereby reduce pain in the salivary gland area.

4. Massage of the parotid salivary gland.

The technique of massaging the parotid salivary gland is as follows: with the fingertips, the first movement is made from the bottom up from the angle of the jaw, when the palm of the lower jaw is touched, the second movement of the fingers is made towards the nose. This simple manipulation improves the outflow of saliva from the gland.

It is very important not to self-medicate, but to seek help from a specialist as soon as possible. As a rule, patients get a consultation with a maxillofacial surgeon, who, after examination and the necessary research, determines the treatment tactics. Dry mouth syndrome (xerostomia). Occurrence of dry mouth after radioactive treatment Massage of the parotid salivary gland with iodine is associated with a decrease in saliva production. This symptom may occur after a week or several months from the day of therapy. Then the inflammation in the salivary glands usually disappears and salivation is restored.

Change in taste. At least a third of patients feel a change in taste after treatment with radioactive iodine. For them, food may have a metallic taste or no taste at all. As a rule, changes in taste sensations disappear after a couple of weeks without special treatment.

Conjunctivitis, inflammation of the lacrimal jellyPS.

According to some reports, the occurrence of inflammation of the conjunctiva (thin smooth tissue that covers the outside of the eye) occurs in only 1-5% of patients treated with radioactive iodine. Inflammation of the lacrimal gland is also rare. If you experience any discomfort in the eye area, you should seek the advice of an ophthalmologist as soon as possible.

Hypoparathyroidism.

The parathyroid glands are responsible for the production of parathyroid hormone, which in turn controls calcium metabolism. Extremely rarely, but after receiving radioactive iodine, a decrease in the function of the parathyroid glands (hypoparathyroidism) may occur. The main symptoms of hypoparathyroidism are tingling on the face, goosebumps in the face and fingers. It is important not to confuse these symptoms with an exacerbation of cervical osteochondrosis. At the slightest doubt, you need to check the level of parathyroid hormone and ionized calcium. If the indicators are normal, then the patient does not have hypoparathyroidism.

Hair loss (alopecia).

Unlike chemotherapy and other cancer treatments, radioactive iodine does not cause hair loss. The most common hair problem is due to low thyroid hormone levels in preparation for radioactive iodine treatment. With the resumption of taking L-thyroxine, complaints of hair loss disappear.

Influence on reproductive functions.

There is still no scientific data on the negative impact of radioactive iodine on the conception or bearing of children. In women after radioiodine therapy, the risk of infertility, problems with bearing or the development of congenital anomalies in children is not higher than the average in the population. It is recommended to plan children one year after radioiodine therapy.

If repeated high doses of radioiodine are expected, then women may be advised to cryopreserve their own eggs, and men - cryopreservation of sperm.

Occurrence of other malignant tumors.

One of the first questions patients ask when discussing radioactive iodine treatment for thyroid cancer is, "Does radioactive iodine cause cancer in other organs?" If the total dose of radioactive iodine reaches 600 mCi or more, the patient is slightly more likely to develop leukemia (a tumor of the hematopoietic system originating from bone marrow cells), compared with the average values ​​in the population. A group of foreign scientists monitored more than 500 patients in order to identify the effect of the combined action of radioactive iodine and external beam radiation therapy. As a result, the development of leukemia in the study group was detected only in three patients, which amounted to 0.5%. It is important to note that at present there is no convincing scientific evidence that radioactive iodine treatment increases the risk of developing malignant tumors of any other organs.

Consultation with a specialist in radioactive iodine treatment