From Big Medical Encyclopedia

DOZNY FIELD (grech, dosis a dose, a portion) — spatio-temporal distribution of a dose or dosage rate of radiation in the irradiated environment.

Biol, action of ionizing radiation on an organism (see. Ionizing radiation ) is in direct dependence on quantity and quality of the energy absorbed by fabrics. Therefore for successful use of various methods radiation therapy (see) and ensuring radiation safety of service personnel it is necessary to know features of distribution of a dose of radiation in the irradiated environment.

Dative is determined by results of measurement of distribution of a dose of radiation in air or phantoms (see. Phantom dosimetric ). Distribution is presented in the form by cards of isodoses on the plan of section of the irradiated area of a body or in the form of the card of isodoses reflecting a radiation situation in rooms where sources of radiation (are located see. Izodoza ).

Distribution of a dose in the irradiated environment defines the choice of a method of radiation therapy. On Dative it is possible to calculate an absorbed dose of radiation in any point of a body, and also an integral absorbed dose (see. Doses of ionizing radiation ) for the purpose of definition of optimum distribution of an absorbed dose of radiation in patol, the center and healthy bodies and fabrics. Optimum Dative provides leading to patol, to the center of clinically reasonable dose of radiation at the minimum radiation of the healthy bodies and fabrics which are also inevitably exposed to beam influence.

During the formation of optimum Dative consider, on the one hand, possibilities of creation of dozny fields of various configuration at static and mobile methods of radiation by means of modern irradiators and a number of the additional creating devices, with another — features of the irradiated object (inhomogeneity of fabrics on density and chemical structure, an irregular geometrical shape), napr, bodies of the person. For calculation of the optimum dozny field use electronic computers.

See also Dosimetry of ionizing radiation

Bibliography: Lindenbraten L. D. Medical radiology, M., 1969, bibliogr.; Pereslegin I. A. and Sarkis I am a N Yu. X. Clinical radiology, M., 1973, bibliogr.; Tyubiana M. and d river. Physical bases of radiation therapy and radiobiology, the lane with fr., M., 1969.

T. G. Pavlova.