Radiation system with inner and outer gantry parts

A radiation system, comprising:

• a gantry including an inner gantry part and an outer gantry part;
• a radiation head mechanically supported by the inner gantry part and rotatable around a rotation axis, said radiation head comprising a treatment radiation source, arranged to direct treatment radiation to a treatment volume in an object;
• and
• a diagnostic imaging system, comprising:
• a diagnostic radiation source supported by the inner gantry part to direct diagnostic radiation onto the object,
• a detector unit responsive to both diagnostic radiation and treatment radiation passing through the object and outputting a signal representative of the detected radiation, and
• a processor, connected to the detector unit, for providing an image of the object based on the received output signal from the detector unit,
• wherein said inner gantry part is rotatably supported by the outer gantry part at two support locations situated, in the direction of the rotation axis, at opposite sides of the treatment volume.