Radiation therapy system

1. A beam delivery system for a radiotherapy system, the beam delivery system comprising a particle accelerator for generating a radiation beam and a positioning apparatus for moving said particle accelerator, wherein said positioning apparatus comprises a counterbalanced lever carrying the particle accelerator.

2. The system of claim 1 , wherein said lever is pivotable at a fulcrum about a horizontal axis.

3. The system of claim 1 , wherein said particle accelerator comprises a beam output device comprising a beam delivery nozzle.

4. The system of claim 2 , wherein said particle accelerator is located on one side of said fulcrum and a counterbalancing unit is provided on the other side of the fulcrum.

5. The system of any claim 1 , wherein said positioning apparatus is rotatable about a vertical axis.

6. The system of claim 1 , wherein the particle accelerator is coupled to the positioning apparatus for rotational movement about at least one axis, or two or three orthogonal axes, with respect to the positioning apparatus.

7. The system of claim 3 , wherein there is no beam transport system between the particle accelerator and the beam output device.

8. The system of claim 7 , wherein the beam output device is fixed with respect to the particle accelerator so that it moves with the particle accelerator.

9. The system of claim 1 located in a treatment room, a plurality of waiting rooms and a respective doorway between each waiting room and said treatment room.

10. The system of claim 9 including a respective patient support apparatus for each waiting room and a respective actuation apparatus for moving each patient support apparatus between a waiting state in which it is located in the respective waiting room and a treatment state in which it is located in a respective one of said treatment locations in said treatment room.

11. The system of claim 10 , wherein each of said treatment locations is a respective part of said treatment room associated with a respective one of said waiting rooms, being adjacent a door of a respective one of said waiting rooms.

12. The system of claim 9 , wherein at least some of said waiting rooms are radially spaced apart around said treatment room.

13. The system of claim 9 , wherein said actuation apparatus is configured to move the respective patient support apparatus in a main axial direction into and out of the treatment room, said main axial direction being radially disposed with respect to said treatment room.

14. The system of claim 13 , wherein said actuation apparatus being configured to move the respective patient support apparatus along two or three orthogonal axes and/or to effect rotational movement of the patient support apparatus about at least one axis.

15. The system of claim 1 , wherein said actuation apparatus comprises an articulated arm coupled between a base and a patient support apparatus.

16. The system of claim 15 , wherein said base is located in a respective waiting room.

17. The system of claim 1 , wherein said positioning apparatus is power operated.

18. The system of claim 1 , further including a control system that is adapted to control said beam delivery system for delivering a radiation beam to a target zone in accordance with a three dimensional beam delivery vector.

19. The system of claim 18 , wherein said control system is configured to control said beam delivery system by operating said positioning apparatus to position said particle accelerator for delivering said radiation beam to said target zone in accordance with said three dimensional beam delivery vector.

20. The system of claim 10 , further including a detector that is adapted to detect movement of a patient on the patient support apparatus, the system being responsive to detected patient movement to adjust the position of said particle accelerator.

21. The system of claim 20 , wherein said control system is responsive to detected patient movement to adjust said beam delivery system for maintaining delivery of said radiation beam to said target zone in accordance with said three dimensional beam delivery vector.

22. The system of claim 1 , wherein said particle accelerator is a proton accelerator and said radiation beam is a proton beam.

23. A radiation therapy system comprising:

a beam delivery system located in a treatment room, the beam delivery system comprising

a particle accelerator for generating a radiation beam, and

a positioning apparatus for moving said particle accelerator to any one of a

plurality of treatment locations in said treatment room,

wherein said positioning apparatus comprises a counterbalanced lever carrying the particle accelerator.

24. The system of claim 23 , wherein said positioning apparatus is rotatable about a vertical axis, and said lever is pivotable at a fulcrum about a horizontal axis.

25. The system of claim 24 , wherein said fulcrum is located at a centre of said treatment room.

26. The system of claim 23 , wherein said positioning apparatus is rotatable about a vertical axis to move said particle accelerator to any one of said treatment locations, said vertical axis preferably being located at the centre of said treatment room.