Patent ID: 8629415

Claim:
A radiation therapy apparatus comprising: a gantry comprising a central aperture that defines a cavity, in which a patient is positionable for irradiation; a positioning device, with which the patient is positionable in the central aperture of the gantry; a radiation head for generating therapeutic radiation that is directable at the patient; and an extension mechanism for the radiation head, wherein the extension mechanism is configured such that, in a first operating mode of the radiation therapy apparatus, the radiation head is disposed inside the gantry such that the gantry has, on a side facing the positioning device, a front surface that is a front limit of the radiation therapy apparatus toward the positioning device, and that in the first operating mode, the radiation head is behind the front surface viewed from the positioning device, and wherein the extension mechanism is configured such that, in a second operating mode of the radiation therapy apparatus, the radiation head, viewed from the positioning device, is movable to be in front of the front surface that in the first operating state is the front limit.