Bases of radio therapy of tumour and non-tumour diseases

Ground of the use of radio therapy at the unmalignant diseases.

At the unmalignant and degenerative-dystrophy diseases as a result of radiation exposure increase circulation of blood, tissues trophy and fagocitosis, the function of the vegetative nervous system gets better, hyperemia and edema diminishes, infiltration is resolves, the pain is diminishes.

Factors, which influence efficiency of radiotherapy

Radiobiologists and experts of radiotherapy aspire to the fullest destruction of tumoural elements at the least damage of surrounding healthy tissues. Application of radiotherapy in malignant tumours is based upon preconditions, which are stated in the previous sections, i.e. on destroying action of radiation of cancer cells and tissues.

The most effective dose which can destroy completely epithelial tumour without expressed damage of surrounding healthy tissues, the absorbed dose 60-70 Gy, and higher total absorbed doses--100-120 Gy are necessary for destruction of tumours.

Significance of volume of irradiated tissues

It is known, that the size of volume of irradiated tissues defines of biological reaction. radiating the small volume of tissues, Раterson achieved a survival unto 5 years in 54 % of the patients, and in the fields which included of Great volumes of tissues only in 38 %. It testifies that, optimal dose should be irradiated to optimum volume of tissues (an optimum dose should be different in radiation exposure of Greater and small volumes of tissues).

It is necessary to remember preservation of safe box of the tumour which limits its Growth, provides regenerative processes after destruction of a tumour.

Definition of dose, rhythm of radiation exposure and volume it is necessary to consider anatomic features of irradiated area and the lymph route. The volume of irradiated tissues should be defined by localization, histological structure, character of Growth, prevalence of malignant tumour, the general condition of the patient and other factors which influence the technique and efficiency of radio therapy. In some cases expediently and operative treatment. Radio therapy in all cases should be carried out in optimum conditions for the patient. It is necessary to estimate risk associated with cancer process and to define, that represents Greater danger-passivity of therapeutic actions or too active treatment. Except for exact observance of cleanly radio therapeutic methodical rules, it is necessary to remember the technical moments, i.e. whenever possible it is necessary to bring a homogeneous dose to the irradiated volume of tumour in order to prevent both overdoses, and small doses in comparison with optimumn choice of technique of radiation exposure it is necessary to find such technical method of radiation exposure which would receive the least dose. It is necessary to define precisely that doses received by the areas of the irradiated organism, and to be assured that any body should receive a dose dangerous to him.

Dependence of therapeutic effect on a kind of radiation

Biological efficiency depends upon the density of ionization or quantity of pairs of ions which arise from unit of a way of run of a photon or a particle, i.e. ionizing radiations cause greater biological effect, than rarely ionizing (section see „ biological action of ionizing radiation ”).