1. Device (21) radiation therapy, comprising: a source (23) of rays, which beam for irradiating the target volume can be guided with at least two mutually opposite directions, the collimator (25) with a plurality of collimator elements for limiting the beam used to treat to form fields (11, 13) irradiation, and due to the length of the collimator elements given resolution field capacity (11, 13) of radiation, wherein the radiation therapy unit is configured such that when the dose distribution at the irradiation amount arr azuetsya by sequentially applying two beams of rays from opposite spatial directions and for etogopredusmotren biasing mechanism which acts such that the irradiation oppositely directed fields (11, 13) irradiation is carried out with an offset such that the two oppositely irradiated field (11, 13) irradiation are shifted one to another at a fraction resolution, and for this purpose both the beam axis of the beams are offset to each other to share sposobnosti.2 resolution. Device (21) radiation therapy according to claim 1, wherein the biasing mechanism is configured so as to implement the offset by a quarter or half resolution defined by collimator elementami.3. Device (21) radiation therapy according to claim 1 or 2, wherein the source (23) rays and a collimator (25) rotatably mounted about an axis (27) of rotation, and due to the length of the collimator elements given resolution field capacity (11, 13) irradiation direction of the axis (27) of rotation, and wherein the biasing mechanism is operable to displacement along the axis (27) vrascheniya.4. approx1. Прибор (21) лучевой терапии, содержащий:источник (23) лучей, от которого луч для облучения целевого объема может направляться с по меньшей мере двух противоположных друг другу направлений,коллиматор (25) с множеством коллиматорных элементов для ограничения применяемого для лечения луча для формирования поля (11, 13) облучения, причем за счет протяженности коллиматорных элементов задается раз
