Radiation therapy - a method of treating tumor (usually malignant) which is irradiated by radiation. The fact that malignant cells are more sensitive to the damaging effects of radiation than healthy cells. This is due to the fact that the metabolism of malignant cells is higher than in normal cells, and in addition, they are characterized by uncontrolled division and growth. Therefore, mutations caused by radiation, faster, and effect on malignant cells, and they soon die.
It should be noted that the radiation therapy of brain tumors radiation is used as in malignant and benign tumors. The reason for this is that brain tumors may be located at a depth where they are not accessible to surgical intervention.
Radiation therapy of brain tumors can be used as a separate type of treatment, and combined together with the surgical technique and chemotherapy. For example, it is used after surgical removal of the tumor to destroy the remaining cancer cells.
Radiation therapy can be used in two ways.
Remotely. At the same radiation exposure is performed using special devices. The treatment is carried out remotely by a period of five days a week course of radiation therapy in this last few weeks. The scheme of radiation therapy depends on tumor type and size, as well as the age of the patient. Such long-term ("stretched") use of radiotherapy in small doses helps protect surrounding healthy tissue from the damaging radiation exposure.
External beam radiotherapy is usually performed on the tumor and adjacent tissues. Less frequently exposed to radiation all the brain. At the same time, the area of the tumor itself may additionally irradiated, for example, using a radioactive implant.
Brachytherapy. This method of radiation therapy may be called, in contrast to the distance "contact." It is based on the implantation of radioactive source (using stereotactic technique) directly into the tumor. This method of radiation therapy is used not only in the treatment of brain tumors, but also other organs, such as the prostate.
Another method of treating brain tumors is the so-called stereotactic radiosurgery. The term "radiosurgery" implies that the emission of Radiation "compiled" into a compact bundle. Radiation exposure in this case is conducted in one session. When the tumor is exposed to radiation radiosurgery powerful beam of radiation pryamonatselennym from different angles. This technique of radiation therapy can direct the power of this radiation on the tumor, when leaving the surrounding healthy tissue intact. This method is also known as the "gamma knife". Usually "gamma knife" is used to treat tumors up to 3.5 - 4 cm in diameter. This is due to the fact that the large size of the tumor increases the required dose of radiation and radiation exposure to healthy brain tissue, so the probability of postradiation complications is high enough. The method of radiosurgery is not nothing to do with children or with elderly patients, as well as the presence of multiple tumor sites or metastases.
The method of radiosurgery in some cases as an alternative to the usual traditional surgery, which allows for treatment without resorting to severe invasive interventions, such as craniotomy (craniotomy), and thus avoid the associated risks.
Side effects of radiotherapy
Side effects of radiotherapy are caused primarily by radiation as the tumor and healthy tissue in the brain and skull. Local side effects of radiotherapy can be expressed in the form of radiation burns of the scalp, increased fragility of blood vessels, the appearance of small foci of hemorrhage or ulceration.
Tumor cells were subjected to irradiation, decay, so absorbed in the blood of their decay products, which affect the body toxic. This leads to patient fatigue, weakness, nausea, vomiting, hair loss, and disruption of hematopoiesis.
Typically, radiation exposure leads to hair loss. The reason for this is the defeat of hair follicles. The new grown hairs are usually milder and of a different color. Sometimes the hair is lost forever.
In addition to hair loss after radiation therapy may experience other reactions on the part of the scalp in the form of redness, itching and pigmentation. Externally, these are areas of skin like a sunburn. Plots of the scalp, which are irradiated, it is best to keep open, but protected from the sun. During this period, is very important for the proper care scalp.
After about 4 - 6 weeks after a course of radiation therapy in patients may occur drowsiness, fatigue, and reduction or loss of appetite. These symptoms usually last for several weeks and are associated with the absorption of the decay products destroy the tumor into the blood. These manifestations gradually disappear on their own.