Radiosensitivity is the sensitivity of the organism (or tissues to the action of ionizing radiation.
Radiosensitivity determine the minimum dose of ionizing radiation see ionizing Radiation, which causes short-term changes of physiological reactions of the body. For a long time, the notion of radiosensitivity was identified with the concept of radiomanagement. However, radiomanagement characterized not short-term physiological changes in the body, and more or less long function disorders and, as a rule, morphological changes in tissues. However, in the literature it is generally accepted term "radiosensitivity", which is used both in the true sense of the word, and to assess radiomanagement.
Various species of fauna and flora have different radiosensitivity (species radiosensitivity). For example, dogs are more radiosensitive animals than rabbits: under uniform irradiation absolutely fatal for dogs is dose 350 R, and rabbits - 800-1000 R. Absolutely lethal dose General exposure to man - 600-700 R. Radiosensitivity changes depending on the time of year (seasonal radiosensitivity). For example, the radiosensitivity of dogs and rabbits during the autumn-winter period is considerably reduced. The radiosensitivity of the body is different in different age groups (age radiosensitivity), however, the literary data on this controversial issue. Contradictory information about sexual radiosensitivity. On the radiosensitivity influenced by the source of the physiological state of the organism and its individual properties (individual radiosensitivity).
Differences in the radiosensitivity are available not only at the level of the whole organism, but also on the level of its tissues, organs, cells, and even molecules. For example, it is known that the morphological changes in blood-forming tissue detected at relatively lower doses than in the muscle or bone. Young, rapidly reproducing cells were more radiosensitive than Mature.
Accumulated in radiobiology information on the issue of radiosensitivity widely used in Oncology practice. Differences in tissue radiosensitivity allow radiation therapy (see) patients with malignant neoplasms: young, proliferating tumor cells have relatively high radiosensitivity and therefore under irradiation damage rather than cells of healthy tissues, inevitably fall into the irradiated field. Radiation therapy of patients account for differences in the age of radiosensitivity. For example, children's reactions to exposure occurs earlier than in adults. Taken into account information about individual radiosensitivity. At baseline patients take into account the increased radiosensitivity of the body during menstruation, special radiosensitivity of tissues, including skin, inflammatory processes.
Efforts was established on his initiative aimed at finding ways to increase the radiosensitivity of the tumor while reducing the sensitivity surrounding healthy tissues and organism as a whole.