Radiation therapy of prostate cancer

Radiation therapy uses high-power X-rays to destroy cancer cells. Radiation is effective in the treatment of cancer, as it deprives cancer cells of the possibility of reproduction. Cancer cells are more susceptible to harmful radiation than healthy cells. Radiation is used to treat many types of cancer, and for several decades it has been used to treat prostate cancer.

Radiation irradiation is also used to treat cancer, which spread beyond the prostate. It can destroy cancer cells, reduce swelling and relieve pain.

Radiation is usually emitted by a large device called a linear accelerator. He, with

, seats a concentrated ray, which is directed to the prostate gland. Radiation can also damage healthy tissues in the prostate, including the bladder and rectum. Therefore, to reduce side effects, the exact location of the prostate gland is established and the ray is directed to this place.

The first step in irradiation treatment is to determine the area of ​​the body that will be exposed to radiation. A three-dimensional scanner shows the location of the prostate and the surrounding organs. A special graphical computer program allows the therapist to rotate the picture in any direction to select the best angle of the irradiation ray application.

The course of radiation treatment usually lasts six to eight weeks with irradiation five days a week. Each session takes about 15 minutes, but most of this time is spent preparing for the procedure. The immediate time of exposure to radiation is only a few minutes. In order for the rays to always be directed to the desired point, there are special devices that support your body in the same position at each session. You will also be asked to always come for treatment with a complete bladder, which will ensure the same location of the prostate. To make it easier for the therapist to find the right place for exposure to radiation, you will get special notes on your skin. Custom-made shields will protect the surrounding areas from the scattered radiation: intestine, anal opening, rectal wall and urethra.

In addition, to determine the exact location of the prostate gland before each session, there is a relatively new technique, using for this small metal markers. These markers are established in the prostate gland in the same way as a biopsy is done. When they are installed, the optical equipment built into the X-ray unit determines the best beam direction for maximum efficiency of the procedure and minimal damage to surrounding tissues. Another method for accurately determining the location of the beam application is to use an ultrasound scan of the prostate with a small sensor located on the lower abdomen.

During the radiation treatment session, you lie on the table, and the linear accelerator moves above you, acting irradiating the cancer tumor.

There is another kind of external irradiation, in which not x-rays but protons are used to destroy cancer. Protons are particles of atoms that almost do not harm surrounding tissues, but effectively destroy

cells, which are directed to the beam. Protons travel in healthy tissues and stay in the irradiated area, where they bring their portion of radiation. This method allows the doctor to use large doses of radiation for irradiation. This kind of radiation therapy is now being studied in several medical centers.

External irradiation is also used after surgery to affect the areas around which the tumor was located. This treatment is applied when a cellular study of prostate tissue shows that after surgery, a small number of cancer cells could remain in the prostate. Irradiation of these cells prevents their further growth. In this case, radiation treatment begins no earlier than two to three months after the operation, and lasts six to seven weeks - a shorter time than when irradiation is the main method of treatment. Radiation treatment is also used when the level of a specific prostate antigen in the blood begins to rise after several months or years after surgical removal of the prostate gland.

Another way of delivering radiation to cells located in the prostate gland is called brachytherapy. With this method, under the control of

ultrasound probe using needles in your prostate is injected with radioactive grains or granules the size of a grain of rice. These grains radiate twice as much radiation as when exposed to external radiation. Brachytherapy can be used alone or in combination with external irradiation or hormonal therapy.

The procedure for the implantation of grains is performed ambulantly, either under general anesthesia or using spinal anesthesia, in which the lower part of the body loses sensitivity.

70 to 150 grains penetrate the interior of the prostate gland and around it with hollow needles that are inserted through the skin of the perineum, the area between the anus and the scrotum. The amount of grains implanted depends on the size of the prostate. This method is often used in the treatment of small or moderate prostate size.

Depending on the stage of cancer in the grains, one or more radioactive substances are used. The most commonly used low-energy isotopes are iodine 125 and palladium 103. Seeds remain in the prostate forever, even after they cease to emit radiation. Other grains containing a more powerful substance, iridium, are introduced into the prostate temporarily. This type of treatment is called high-dose brachytherapy. You-cocodized brachytherapy is considered temporary, because the grains eventually disappear.

Brachytherapy, which uses permanent grains, is used more often, since high-dose brachytherapy is usually used in conjunction with a four-five-week course of external exposure, which makes it less convenient for the patient.

To help the doctor »arrange the grains in your prostate gland and around it, an ultrasound probe is used in the procedure. The spacer attached to the outer wall of the probe is pointed upwards and rests against the crotch. It helps to guide and keep in a stable position needles carrying grains.

Grains containing iodine and palladium usually produce radiation within a few millimeters of the radius where they are installed. Although it is believed that this type of radiation should not spread beyond your prostate gland, in the first two months after implantation, you should not have long close contacts( closer than 60 cm) with children and pregnant women, since they are particularly susceptible to radiation. The stock of radiation in granules runs out during the year.

Studies have shown that brachytherapy can control or stop the development of cancer in 90% of men for five years and 70 to 85% for ten years.

Implantation of radioactive granules usually gives the same side effects as external irradiation.

The procedure for the implantation of radioactive grains or granules to treat the prostate( brachytherapy) usually takes about two hours. To control the proper arrangement of grains, an ultrasound probe is inserted into the rectum. Grains that radiate radiation that destroys or kills cancer cells usually remain in the prostate forever.

The duration of side effects associated with urination - including increased frequency of urination and burning sensation - may be less than with external exposure.