RADIATION THERAPY SYSTEMS AND METHODS

• US 20180133514A1
• Filed: 12/21/2017
• Published: 05/17/2018
• Est. Priority Date: 04/01/2016
• Status: Active Grant

• Current Assignee: Varian Medical Systems Incorporated (Siemens AG)
• Original Assignee: Varian Medical Systems Incorporated (Siemens AG)
• Inventors: MANSFIELD, Stanley
• Granted Patent: US 10,307,618 B2
• Time in Patent Office: Days
• CPC Class Codes: A61N 2005/1087 Ions; Protons
• CPC Class Codes: A61N 2005/1095 Elements inserted into the radiation path within the system, e.g. filters or wedges
• CPC Class Codes: A61N 5/1043 Scanning the radiation beam, e.g. spot scanning or raster scanning
• CPC Class Codes: A61N 5/1049 for verifying the position of the patient with respect to the radiation beam
• CPC Class Codes: A61N 5/1067 in real time, i.e. during treatment
• CPC Class Codes: A61N 5/1077 Beam delivery systems

Abstract

A radiation therapy system includes an accelerator and beam transport system that generates a beam of particles. The accelerator and beam transport system guides the beam on a path and into a nozzle that is operable for aiming the beam toward an object. The nozzle includes a scanning magnet operable for steering the beam toward different locations within the object, and also includes a beam energy adjuster configured to adjust the beam by, for example, placing different thicknesses of material in the path of the beam to affect the energies of the particles in the beam.

Claims

1. A radiation therapy system, comprising:

an accelerator and beam transport system that generates a beam of particles, wherein the accelerator and beam transport system comprises focusing magnets along the path of the beam; and

a nozzle operable for aiming the beam toward an object, wherein the nozzle comprises;

scanning magnets operable for steering the beam toward different locations within the object; and

a beam energy adjuster configured to adjust the beam by affecting energies of the particles in the beam.

2. The radiation therapy system of claim 1, wherein the beam energy adjuster comprises a range shifter configured to place different thicknesses of material in the path of the beam to affect the distance that the particles penetrate into the object and position a Spread Out Bragg Peak within the object.

3. The radiation therapy system of claim 2, wherein the beam energy adjuster further comprises a range modulator configured to place different thicknesses of material in the path of the beam to change the energies of at least a portion of the particles and achieve the Spread Out Bragg Peak.

4. The radiation therapy system of claim 1, wherein the beam energy adjuster comprises a range modulator configured to place different thicknesses of material in the path of the beam to change the energies of at least a portion of the particles and achieve a Spread Out Bragg Peak.

5. The radiation therapy system of claim 4, wherein the range modulator comprises a plurality of arms extending from a hub, the arms having non-uniform thicknesses, wherein the range modulator is operable to rotate about the hub allowing the beam to pass through at least one of the arms.

6. The radiation therapy system of claim 5, wherein the range modulator is configured to move in a first direction between a position that is completely out of the path of the beam and a position that is in the path of the beam, wherein the first direction is transverse to the path of the beam, wherein further the range modulator is also configured to move in a second direction different from the first direction and transverse to the path of the beam.

7. The radiation therapy system of claim 1, wherein the focusing magnets adjust the energies of the particles in the beam to vary sizes of spots where the beam intersects the different locations in the object.

8. A method for planning radiotherapy treatments, the method comprising:

defining a first scan pattern for directing a first radiation beam from a first nozzle into a planning target volume, wherein the first scan pattern comprises a plurality of different target line segments in the planning target volume; and

generating parameters for configuring the first nozzle, wherein the parameters affect energies of charged particles in the radiation beam to create an adjusted beam that delivers a dose having a Spread Out Bragg Peak (SOBP) along a respective target line segment of the plurality of different target line segments.

9. The method of claim 8, further comprising specifying an angle of the first nozzle relative to the planning target volume for each of the different target line segments.

10. The method of claim 8, further comprising defining a second scan pattern for directing a second radiation beam from a second nozzle into the planning target volume, wherein the second scan pattern comprises a second plurality of different target line segments in the planning target volume, wherein the first nozzle delivers the first radiation beam from a first direction and the second nozzle delivers the second radiation beam from a second direction different from the first direction.

11. The method of claim 8, wherein the parameters comprise parameters that control movement of a range shifter in the first nozzle, wherein the range shifter is configured to place different thicknesses of material in the path of the radiation beam to affect the distance that the charged particles penetrate into the planning target volume and position the SOBP within the planning target volume.

12. The method of claim 11, wherein the parameters further comprise parameters that control movement of a range modulator in the first nozzle, wherein the range modulator is configured to place different thicknesses of material in the path of the radiation beam to change the energies of at least a portion of the charged particles and achieve the SOBP.

13. The method of claim 8, wherein the parameters comprise parameters that control movement of a range shifter in the first nozzle, wherein the range shifter is configured to place different thicknesses of material in the path of the beam to change the energies of at least a portion of the particles and achieve the SOBP.

14. The method of claim 8, comprising delivering the dose within one second.

15. A radiation therapy method, comprising:

tracking motion of a target volume; and

delivering a dose along a target line segment in the target volume to coincide with a position of the target volume, wherein the dose is delivered in a period of time short enough to counter uncertainties in the position due to the motion of the target volume.

16. The method of claim 15, wherein said delivering further comprises delivering a dose of at least four grays along the target line segment in less than one second.

17. The method of claim 15, further comprising:

placing material in the path of a beam of particles in a nozzle of a radiation therapy system to affect energies of the particles in the beam and create an adjusted beam; and

repeating said tracking, delivering, and placing to deliver doses along different target line segments in the target volume until the target volume has been irradiated to a prescribed dose, wherein the doses are each delivered in a period of time short enough to counter uncertainties due to the motion of the target volume.

18. The method of claim 17, wherein said placing comprises:

moving a range modulator in the nozzle in a first direction between a position that is completely out of the path of the beam and a position in the nozzle that is in the path of the beam, wherein the range modulator comprises a plurality of arms extending from a hub, the arms having non-uniform thicknesses; and

with the range modulator in the path of the beam, rotating the range modulator about the hub to place at least one of the arms in the path of the beam, wherein the energies of the particles is varied according to the thicknesses of the arms that pass through the beam, and wherein the thicknesses of the arms that pass through the beams is varied by moving the range modulator back-and-forth in the first direction.

19. The method of claim 17, further comprising varying the distance that the particles penetrate into the target volume with a range shifter that is in the nozzle and is configured to place a different thickness of the material in the path of the beam according to the motion of the target volume.

20. The method of claim 17, wherein said placing comprises moving components of a range shifter in the path of the beam in the nozzle to present a different thickness of the material to the beam according to the motion of the target volume.