Radiotherapy device

1. A radiotherapy apparatus comprising:

a gantry rotation mechanism configured to be positioned between a support structure and a gantry, the gantry comprising a source of radiation attached to the gantry and configured to emit radiation along a radiation axis, wherein the gantry rotation mechanism comprises at least a first rotatable wedge and a second rotatable wedge each comprising a rotary actuator, and wherein the gantry rotation mechanism is configured to:

rotate the gantry about a gantry rotation axis; and

tilt the gantry with respect to the gantry rotation axis by effecting relative rotation of the first and second rotatable wedges to define at least a first configuration and a second configuration wherein, in the first configuration, the radiation axis is perpendicular with the gantry rotation axis, wherein in the second configuration, the radiation axis is non-perpendicular with the gantry rotation axis, wherein the first rotatable wedge and the second rotatable wedge are offset from one another such that, in both the first configuration and the second configuration, the radiation axis and the gantry rotation axis meet at a same point in space to define an isocentre that is common to both the first configuration and the second configuration, and wherein the offset results in a center of rotation of the second rotatable wedge that does not lie on a rotation axis of the first wedge.

2. The radiotherapy apparatus of claim 1 , further comprising:

the gantry;

the source of radiation attached to the gantry and configured to emit radiation along the radiation axis; and

the support structure for supporting the gantry.

3. The radiotherapy apparatus of claim 2 , wherein the gantry rotation axis passes through the gantry rotation mechanism, and wherein the gantry rotation axis is a fixed axis that is fixed with respect to the support structure.

4. The radiotherapy apparatus of claim 2 , wherein the radiation source is fixedly attached to the gantry.

5. The radiotherapy apparatus of claim 2 , further comprising at least one of an imaging apparatus and a beam stop attached to the gantry, the at least one of the imaging apparatus and the beam stop being positioned diametrically opposite the radiation source such that the radiation axis passes through the at least one of the imaging apparatus and the beam stop.

6. The radiotherapy apparatus of claim 2 , further comprising a patient support surface positioned such that a patient positioned on the patient support surface is capable of being positioned along the gantry rotation axis.

7. The radiotherapy apparatus of claim 2 , wherein the support structure supports the gantry and the gantry rotation mechanism.

8. The radiotherapy apparatus of claim 2 , wherein the gantry rotation mechanism is further configured to tilt the gantry to adjust an angle which the radiation axis makes with the gantry rotation axis.

9. The radiotherapy apparatus of claim 2 , wherein the gantry rotation mechanism comprises a rotatable actuator and a hexapod, said hexapod comprising a first platform and a second platform, the first platform being coupled with the rotatable actuator and the second platform being coupled with the gantry, wherein the rotatable actuator is configured to rotate the gantry about the gantry rotation axis.

10. The radiotherapy apparatus of claim 2 , wherein the gantry rotation mechanism comprises at least one of:

a hexapod; or

a wedge element.

11. A method of manufacturing a radiotherapy apparatus for delivering radiation to a patient, comprising:

providing a gantry;

providing a source of radiation attached to the gantry, the radiation source being configured to emit radiation along a radiation axis;

providing a support structure for supporting the gantry; and

positioning a gantry rotation mechanism between the support structure and the gantry, wherein the gantry rotation mechanism comprises at least a first rotatable wedge and a second rotatable wedge each comprising a rotary actuator, and wherein the gantry rotation mechanism is configured to:

rotate the gantry about a gantry rotation axis; and tit the gantry with respect to the gantry rotation axis by effecting relative rotation of the first and second rotatable wedges to define at least a first configuration and a second configuration, wherein, in the first configuration, the radiation axis is perpendicular with the gantry rotation axis wherein in the second configuration, the radiation axis is non-perpendicular with the gantry rotation axis, wherein the first rotatable wedge and the second rotatable wedge are offset from one another such that, in both the first configuration and the second configuration, the radiation axis and the gantry rotation axis meet at a same point in space to define an isocentre that is common to both the first configuration and the second configuration, and wherein the offset results in a center of rotation of the second rotatable wedge that does not lie on a rotation axis of the first wedge.

12. A method of adjusting a configuration of a radiotherapy device, the radiotherapy device for delivering radiation to a patient, the device comprising:

a gantry; a source of radiation attached to the gantry and configured to emit radiation along a radiation axis;

a support structure for supporting the gantry; and

a gantry rotation mechanism positioned between the support structure and the gantry,

wherein the gantry rotation mechanism is configured to rotate the gantry about a gantry rotation axis and tilt the gantry with respect to the gantry rotation axis such that the radiation axis is non-perpendicular with the gantry rotation axis, and wherein the gantry rotation mechanism comprises at least a first rotatable wedge and a second rotatable wedge each comprising a rotary actuator;

the method comprising:

tilting the gantry into a first configuration in which the radiation axis is perpendicular with the gantry rotation axis; and

tilting the gantry into a second configuration by effecting relative rotation of the first and second rotatable wedges, in which the radiation axis is non-perpendicular with the gantry rotation axis;

wherein the first rotatable wedge and the second rotatable wedge are offset from one another such that, in both the first configuration and the second configuration, the radiation axis and the gantry rotation axis meet at a same point in space to define an isocentre that is common to both the first configuration and the second configuration, and wherein the offset results in a center of rotation of the second rotatable wedge that does not lie on a rotation axis of the first wedge.

13. A non-transitory computer readable medium comprising computer-executable instructions which, when executed by a processor, cause the processor to control a gantry rotation mechanism to perform the method of claim 12 .