29.01.2008 // Minatom.ru

Atom serves medicine: interview with director of Medical Radiological Research Center of Russian Academy of Medical Sciences A.Tsyb

The key program of the Medical Radiological Research Center of the Russian Academy of Medical Sciences (Obninsk) is research in the field of medical radiology, general and applied radio-biology, radiation medicine and epidemiology. The Center has developed a number of effective treatment technologies based on the use of energy of atom. The director of the center, academician A.Tsyb has told us about their use, particularly, in oncology.

— Today, we have almost 2,000,000 cancer patients. Do they have chances of recovery?

— Today, in economically developed countries the recovery rate is 70%. Due to Europe Against Cancer program, the mortality rate among cancer patients in Europe is steadily declining. In our country, the cancer rate is quite high: 450,000 people a year with 300,000 people dying. In the last decade the cancer rate has grown by 25.5%. In the next decade it is expected to grow by 15%.

For example, the rate of prostate cancer in Obninsk and Kaluga region is reported to be higher than the average index for Russia. The Legislative Assembly of the region has adopted a Male Health program and our Center will shortly start to treat local men free of charge.

Prostate cancer is widely spread all over the world. For example, in the United States it is one of the widest spread diseases among men over 50. 200,000–220,000 Americans develop prostate cancer each year.

In Russia this index is almost 10 times lower but mostly due to poor diagnostics and the low average life expectancy of Russian men (57). Timely detection of prostate cancer is key precondition of effective treatment. In the United States all men over 50 undergo medical examination every year. 80% of prostate cancer cases are detected at early stages. In Russia this index is much lower. 

Until recently we have had two radical methods of treating prostate cancer: surgery causing extensive loss of blood or distant external irradiation causing damage of healthy organs and tissues. Both cases imply long hospitalization and possible impotence and enuresis. Brachytherapy has turned the situation around. 

— This is a new term in medicine. What does it mean?

— Brachytherapy, also known as sealed source radiotherapy or endocurietherapy, is a form of radiotherapy where a radioactive source is placed inside or next to the area requiring treatment. Brachytherapy is commonly used to treat localized prostate cancer[1] and cancers of the head and neck. Brachy is from a Greek word for «short», so brachytherapy roughly translated is short distance therapy.

Brachytherapy is a bloodless operation carried out under control of ultrasound or tomograph by means of unique equipment allowing biopsy of spermatocysts.  

The technology has been developed by American professor Panos Koutrouvelis, the director of URO-Radiology Prostate Institute (Washington). In Russia it has been improved and tested in Obninsk. Our specialists have designed and patented a new stereotactic attachment with special software. This system allows treating prostate cancer even at its third stage (with spermatocysts and urinary bladder affected).

Our Center has already carried out almost 300 such operations. Now, our experience is being adopted by hospitals in Moscow, St.Petersburg, Yekaterinburg, Nizhniy Novgorod, Samara. We could disseminate this technology all over Russia and train specialists for its effective application.

— Could you describe the process of treatment?

Radioactive material based on iodine-125 is pushed to the site of the tumor through a delivery device – thin hollow needle (50–90 depending on the size of the tumor). The operation is carried out by a team of our specialists trained in the United States, Greece and Germany. Before surgery the patient undergoes tomography. The pictures are sent to beam therapy planning system for 3D modeling and selection of the best implantation scenario.

Implantation is carried out under general anesthesia affecting the lower part of the body and lasting for an hour. This is an easy and harmless procedure even for old people with diabetes, hypertension and heart problems. The operation has no complications and is effective even in case of large metastasis. 

After removal of the needles, the radioactive material emits radiation for several weeks or months. Iodine-125 half-decays within 60 days. Brachytherapy allows injecting 140–160 Gy, which is 2–3 times as much as in case of distant irradiation. The risk of damage of bladder, urethra or rectum is very low while the recovery rate is very high – 92%-98%.

The patient can leave the hospital the next day after the surgery and return to his everyday life. 83% of men under 70 retain their sexual potency.

— After the Chernobyl accident, people began associating radiation with death. But in the hands of a doctor it may turn into new life, mayn’t it?

— Yes, it may. The isotopes of iodine emitted by the damaged Chernobyl reactor caused lots of thyroid gland problems, but the same isotopes are now used in radio-iodine therapy: iodine-125 in urology, iodine-131 for treatment of thyroid carcinoma and thyrotoxicosis. We have reequipped our relevant department and have treated almost 800 people.

Our goal for the near future is to treat 1,500 people a year. Our key problem is lack of money for reconstruction of the purification plants and enlargement of the radio-nuclide clinic. For example, in Europe and the United States they no longer use surgery for treating thyrotoxicosis and prefer radiation. Radio-therapy helps to avoid two serious complications: damage of the superior laryngeal nerve (7% of cases) and removal of parathyroid glands (resulting in deficit of calcium).

Surgery implies long period of rehabilitation, while radio-therapy takes just 2–3 days. Almost 50,000 Russians have problems with thyroid gland. In order to treat them all, we need lots of similar departments all over the country, first of all, in the cities having necessary infrastructure and experience: Moscow, Tomsk, Dmitrovgrad, Snezhinsk. As for the moment, our department is the only one in Russia.

Today, radio-therapy is recognized as one of the most effective ways to treat cancer. Almost 70% of cancer patients need radio-therapy.

— However, some patients have radiation-resistant forms of cancer, don’t they?

— In such cases, we replace gamma radiation with dense ionizing radiation, particularly, neutron radiation. Almost 500 cancer patients have been treated at the medical section of the BR-10 nuclear reactor situated in the territory of the Institute of Physics and Power Engineering. Our experience has proved the efficiency of the use of fast neutrons of a nuclear reactor, first of all, for treatment of breast, heat and neck cancers.

Combined radiation therapy has proved to be the best: use of neutrons (20% of the total dose) is combined with traditional methods of radiation therapy. Such combination helps us to avoid the damage of healthy tissues and to actively use neutrons as a way to preserve affected organs. In some cases, preliminary fast neutron irradiation allows effectively removing the remains of the tumor.

Neutron capture therapy is also quite a promising way to treat cancer. Boron, lithium or gadolinium is injected into organism for capturing thermal and epithermal neutrons. This therapy is based on the principle of selective irradiation of the tumor with no damage caused to healthy organs and tissues. This method has proved its efficiency in treatment of some incurable types of cancer, for example, different types of brain cancer.

However, we can’t apply our experience on a large scale because in some regions we have no modern equipment and qualified personnel. If we want to meet the international standards in the sphere, we must modernize our equipment. This is one of the key priorities of the Health and Social Development Ministry. And our nuclear research companies could help in the matter.

Oleg Chechin