A radiation treatment device is provided. The device includes an imaging unit and a single radiotherapy unit adjacent to a second end of the imaging unit. The imaging unit includes a first opening at a first end of the imaging unit adapted to receive a patient; at least one imaging source; and at least one imager arranged opposite the imaging source. The imaging source and the imager are rotatable about the rotational axis. The radiotherapy unit includes a source body carrying radioactive sources and a collimator having collimation channels. The collimation channels permit treatment beams emitted by the radioactive sources to be projected inside the imaging unit and focused at an intersection point located within an imaging beam of the imaging unit. The source body and the collimator are arranged concentric about the rotational axis and close a second opening at the second end.