High dose rate radiotherapy, system and method

Patent metadata

Field	Value
Publication number	US-12005274-B2
Application number	US-202217697430-A
Country	US
Kind code	B2
Filing date	Mar 17, 2022
Priority date	Mar 17, 2022
Publication date	Jun 11, 2024
Grant date	Jun 11, 2024

Abstract

A radiotherapy system includes an X-ray target configured to convert an incident electron beam into a therapeutic X-ray beam, a purging magnet configured to redirect unwanted particles emitted from the X-ray target away from the therapeutic X-ray beam, and a particle collector configured to absorb the unwanted particles subsequent to redirection by the purging magnet. The particle collector may be configured to dissipate at least 50% of the energy of the incident electron beam.

First claim

I claim:

1. A radiotherapy system comprising:
an X-ray target configured to convert an incident electron beam into an X-ray beam, wherein the X-ray beam delivers a radiation rate of greater than or equal to 40 grays per second;
a purging magnet configured to redirect unwanted particles emitted from said X-ray target away from said X-ray beam; and
a particle collector configured to absorb said unwanted particles subsequent to a redirection by said purging magnet.

2. The radiotherapy system of claim 1 , wherein said particle collector is configured to dissipate at least 50% of an energy of said incident electron beam.

3. The radiotherapy system of claim 1 , wherein said X-ray target is less than 3.5 mm thick.

4. The radiotherapy system of claim 1 , wherein said X-ray target comprises metals having an atomic number greater than or equal to 42.

5. The radiotherapy system of claim 1 , wherein said X-ray target comprises tungsten (W).

6. The radiotherapy system of claim 1 , wherein said X-ray target is configured to dissipate less than 25% of an energy of said incident electron beam.

7. The radiotherapy system of claim 1 , wherein said particle collector is configured to dissipate at least 75% of an energy of said incident electron beam.

8. The radiotherapy system of claim 1 , wherein said particle collector comprises materials having an atomic number less than 42.

9. The radiotherapy system of claim 8 , wherein said particle collector comprises a cladding including X-ray absorptive materials.

10. The radiotherapy system of claim 1 , wherein said incident electron beam comprises an electron energy of at least 50 MeV.

11. The radiotherapy system of claim 1 , wherein said X-ray target is configured to rotate through said incident electron beam.

12. A radiotherapy system configured for a FLASH radiotherapy, said radiotherapy system comprising:
a bremsstrahlung X-ray target configured to convert a portion of a stream of electrons into X-rays;
a purging magnet configured to redirect particles escaping from said bremsstrahlung X-ray target while passing said X-rays; and
a particle collector configured to absorb said escaping particles subsequent to a redirection by said purging magnet.

13. The radiotherapy system of claim 12 , further comprising:
a linear accelerator configured to accelerate the stream of electrons to an energy of at least 50 MeV.

14. The radiotherapy system of claim 12 , further comprising:
a plurality of scanning magnets configured to adjust a location of said stream of electrons.

15. The radiotherapy system of claim 14 , wherein said plurality of scanning magnets are configured to modify a beam profile of said X-rays.

16. The radiotherapy system of claim 14 , wherein said purging magnet is configured to adjust to changes in a location of said stream of electrons due to actions of said plurality of scanning magnets.

17. The radiotherapy system of claim 12 , wherein said bremsstrahlung X-ray target comprises metals having an atomic number greater than or equal to 42.

18. The radiotherapy system of claim 12 , wherein said particle collector comprises materials having an atomic number less than 42.

19. The radiotherapy system of claim 12 , wherein said particle collector comprises a cladding including X-ray absorptive materials.

20. The radiotherapy system of claim 12 , wherein said particle collector is configured to absorb at least four times as much energy from said stream of electrons in comparison to energy absorbed by said bremsstrahlung X-ray target.

21. The radiotherapy system of claim 12 , wherein said particle collector comprises internal cooling channels configured for a cooling liquid to remove heat from said particle collector.

22. The radiotherapy system of claim 12 , wherein said particle collector is configured to absorb and dissipate at least 20 kilowatts of power from said escaping particles.

23. A method of operating a radiotherapy system, the method comprising:
impinging an electron beam on an X-ray target to generate an X-ray beam, wherein said X-ray target includes metals having an atomic number greater than or equal to 42;
redirecting unwanted particles out of the X-ray beam by a purging magnet; and
absorbing said unwanted particles by a particle collector, wherein said particle collector includes materials having an atomic number less than 42.

24. The method of claim 23 , further comprising:
adjusting a magnetic field of said purging magnet to correspond to scanning of said electron beam.

Assignees

• Varian Med Sys Inc

Inventors

• Clayton James

Classifications

• H05H9/048

  Lepton LINACS · CPC title

• H05G2/00

  Apparatus or processes specially adapted for producing X-rays, not involving X-ray tubes, e.g. involving generation of a plasma (X-ray lasers H01S4/00) · CPC title

• H01J35/30

  by deflection of the cathode ray · CPC title

• H01J35/22

  specially designed for passing a very high current for a very short time, e.g. for flash operation · CPC title

• H01J35/10

  Rotary anodes; Arrangements for rotating anodes; Cooling rotary anodes · CPC title