Compac gantry for particle therapy

1. An isocentric gantry designed for rotating around an axis of rotation and for delivering a particle beam for use in particle therapy, comprising:

a gantry beam line having a gantry entrance point for entering said particle beam into the gantry in a direction essentially parallel with the axis of rotation;

bending means for bending the particle beam in a single plane and delivering said particle beam at an isocenter in a direction essentially perpendicular to the axis of rotation, wherein said bending means include:

first bending means configured for bending the particle beam away from said axis of rotation,

second bending means configured for bending the particle beam towards the axis of rotation, and

third bending means configured for bending the particle beam to said direction essentially perpendicular to the axis of rotation, said third bending means having a bending angle smaller than 80°; and

particle beam scanning means installed in the beam line and configured for scanning said particle beam in both X and Y directions over a target area at the isocenter, wherein the scanning means is located between the second and the third bending means.

2. The isocentric gantry of claim 1 , wherein the bending means comprise dipole magnets.

3. The isocentric gantry of claim 1 , wherein the bending means consists of 3 dipole magnets, where the first dipole magnet bends the beam away from said axis of rotation, the second dipole magnet bends the beam towards the axis of rotation, and the third dipole magnet bends the beam to said direction essentially perpendicular to the axis of rotation and by an angle smaller than 80°.

4. The isocentric gantry of claim 1 , wherein the third bending means has a bending angle of 60°.

5. The isocentric gantry of claim 3 , further comprising quadrupole magnets in the beam line section between the first and second dipole magnet, and wherein the beam line section between the second and the third dipole magnet has no quadrupole magnets.

6. The isocentric gantry of claim 1 , further comprising means for rotating said gantry over an angular range of at least 180°.

7. The isocentric gantry of claim 1 , wherein the particle beam scanning means comprises a combined X-Y scanning magnet.

8. An isocentric gantry designed for rotating around an axis of rotation and for delivering a particle beam for use in particle therapy, comprising:

a gantry beam line having a gantry entrance point for entering said particle beam into the gantry in a direction essentially parallel with the axis of rotation;

a sequence of dipole magnets arranged for bending the particle beam in a single plane and delivering said particle beam at an isocenter in a direction essentially perpendicular to the axis of rotation,

quadrupole magnets for focusing and defocusing said particle beam; and

a first scatterer and a second scatterer installed in the beam line and adapted to provide a broad beam in both X and Y directions at the isocenter, the first scatterer being located between two dipole magnets of said sequence of dipole magnets,

wherein in said sequence of dipole magnets, the sum of the bending angles of the dipole magnet or magnets which are located downstream of the first scatterer is smaller than 80°;

wherein the sequence of dipole magnets comprises a first dipole magnet configured to bend the particle beam away from said axis of rotation, a second dipole magnet configured to bend the particle beam towards the axis of rotation, and a third dipole magnet configured to bend the particle beam to said direction essentially perpendicular to the axis of rotation, said third dipole magnet having a bending angle smaller than 80°, and

wherein the first scatterer is installed between said second dipole magnet and said third dipole magnet and the second scatterer is installed after said third dipole magnet.

9. The isocentric gantry of claim 8 , wherein the third dipole magnet has a bending angle of 60 °.

10. A particle therapy method for delivering a particle beam to a target by an isocentric gantry designed for rotating around an axis of rotation and for delivering the particle beam to the target in a direction essentially perpendicular to the axis of rotation, comprising the steps:

providing a particle beam at an entrance point of said gantry, in a direction essentially parallel with the axis of rotation;

bending the particle beam, downstream of the entrance point, within the gantry, to a direction away from the axis of rotation;

bending the particle beam, downstream of the bending to a direction away from the axis of rotation, within the gantry, to a direction towards the axis of rotation;

scanning the particle beam, downstream of the bending to a direction towards the axis of rotation, within the gantry in both X and Y directions; and,

bending the particle beam, downstream of scanning the particle beam in the X and Y directions, within the gantry, by a total angle smaller than 80° and greater than 0°.

11. The method of claim 10 , wherein the steps of bending the particle beam are performed with dipole magnets.

12. The method of claim 10 , wherein the step of bending the particle beam by a total angle smaller than 80° is a step of bending the particle beam by a total angle of 60°.

13. The method of claim 10 , further comprising providing quadrupole magnets between the step of bending the particle beam to a direction away from the axis of rotation and the step of bending the particle beam to a direction towards the axis of rotation.

14. The method of claim 10 , further comprising providing means for rotating said gantry over an angular range of at least 180°.

15. An isocentric gantry designed for rotating around an axis of rotation and for delivering a particle beam for use in particle therapy, comprising:

a gantry beam line having a gantry entrance point for entering said particle beam into the gantry in a direction essentially parallel with the axis of rotation;

a sequence of dipole magnets arranged for bending the particle beam in a single plane and for delivering said particle beam at an isocenter in a direction essentially perpendicular to the axis of rotation,

quadrupole magnets for focussing and defocusing said particle beam; and

particle beam scanning means installed between two dipole magnets of the sequence of dipole magnets and configured for scanning said particle beam in both X and Y directions over a target area at the isocenter,

wherein in said sequence of dipole magnets, the sum of the bending angles of the dipole magnets which are located downstream of said particle beam scanning means is smaller than 80°.

16. The isocentric gantry of claim 15 , wherein the sequence of dipole magnets consists of a first, a second, and a third dipole magnet, where the first dipole magnet bends the beam away from said axis of rotation, the second dipole magnet bends the beam towards the axis of rotation, and the third dipole magnet bends the beam to said direction essentially perpendicular to the axis of rotation and by an angle smaller than 80°.

17. The isocentric gantry of claim 16 , wherein the third dipole magnet has a bending angle of 60°.

18. The isocentric gantry of claim 15 , further comprising quadrupole magnets between the beam line section between the first and second dipole magnet, and wherein the beam line section between the second and the third dipole magnet has no quadrupole magnets.

19. The isocentric gantry of claim 15 , further comprising means for rotating said gantry over an angular range of at least 180°.

20. The isocentric gantry of claim 15 , wherein the particle beam scanning means comprises a combined X-Y scanning magnet.

21. The isocentric gantry of claim 16 , wherein the particle beam scanning means comprises a combined X-Y scanning magnet.