Radiotherapy device

A radiotherapy apparatus comprising, a radiation source 332 attached to a gantry 330 to emit radiation along a radiation axis 390, a gantry support 310, and positioned between the gantry 330 and gantry-support 310 is a rotation mechanism 320 that both rotates the gantry 330 about a rotation axis 380 and tilts the gantry relative to the gantry rotation axis 380 so that the radiation axis 390 is non-perpendicular to the rotation axis 380. Preferably, rotation-mechanism 320 tilts the gantry 330 relative to the rotation-axis 380 to define a first configuration, where radiation-axis 390 is perpendicular to the rotation-axis 380, and a second configuration, where radiation axis 390 is not perpendicular to the rotation axis 380. Rotation mechanism 320 may comprise first and second wedges 324&325 offset from one another so that in both first and second and configurations, the radiation and rotation axes 390&380 meet at a same point in space defining an isocentre common to both configurations. The rotation-mechanism may comprise a rotatable actuator and a hexapod comprising a first platform coupled to the rotatable-actuator and a gantry coupled second platform, where the rotatable actuator rotates the gantry about the rotation axis. Applicable to coplanar and non-coplanar treatment.