FIELD: medicine.SUBSTANCE: group of inventions refers to medical technology, namely to the means for radiotherapy and medical imaging. Radiotherapy system contains the block of three-dimensional visualization in real time, which generates the base image and three-dimensional real-time image of at least a portion of the body region of the subject including the target and one or more bodies at risk (ODA), the recording unit that deformably registers the plan image of the body region of the subject and the base image, and also maps the capability of the tissue to absorb radiation in the planned image onto the base image, the motion block that measures the movement of the target volume and ODA in the process of radiotherapy based on the real-time images, and the real-time dose calculation subsystem that calculates the irradiation dose based on the ability of the tissue to absorb radiation applied as the map from the base image or the plan image to three-dimensional images in real time, the dose of irradiation in real time is based on the initial intensities of the radiation beams leading to and crossing each voxel, weakening along the trajectory of each of the radiation beams and the time, at which each beam intersects each voxel. Method of radiation therapy is provided by means of the operation of the radiation therapy system using the non-timed machine-readable storage medium for radiotherapy and the electronic data processing device for radiotherapy. Radiation therapy system according to the second option comprises the linear accelerator (LINAC), which is configured in order to generate the plurality of radiation beams into at least one target volume in the body of the subject, where each beam has the size, shape, direction, intensity and duration, which are given on the basis of the radiotherapy plan, the robot-controlled ultrasound transducer, which is designed in order to generate the 3-dimensional (3D) ultrasound images of the body region of the subject including
