Irradiation method and system

1. An irradiation method for irradiating a target volume of a subject, the method comprising:

providing thermal neutron absorbing nuclides in or adjacent to the target volume of the subject, in the absence of a separate proton-absorbing substance provided to the subject; and

producing neutrons by irradiating nuclei with a beam of particles consisting of any one or more of protons, deuterons, tritons or heavy ions, thereby prompting production of the neutrons in the subject through non-elastic collisions within the subject between the nuclei and the particles;

wherein the neutron absorbing nuclides absorb neutrons produced in the non-elastic collisions, thereby producing capture products or fragments that irradiate the target volume.

2. The method as claimed in claim 1 , further comprising configuring the beam of particles so as also to irradiate the target volume.

3. The method as claimed in claim 1 , wherein the beam comprises protons, 4 He, 10 C, 11 C, 12 C, 15 O, 16 O, highly energetic protons or heavy ions.

4. The method as claimed in claim 1 , further comprising providing the thermal neutron absorbing nuclides in the form of a composition containing 10 B or 157 Gd.

5. The method as claimed in claim 1 , wherein the composition is preferentially absorbed by a malignant target tissue.

6. The method as claimed in claim 1 , wherein the capture products or fragments comprise energetic charged particles of high relative biological effectiveness or other energetic charged particles.

7. A method of irradiating biological tissue using a proton, deuteron, triton or heavy ion beam, the method comprising irradiating a target volume that includes the biological tissue according to the method of claim 1 .

8. The method as claimed in claim 1 , wherein the beam of particles has a Bragg peak that is outside the subject.

9. A method of inhibiting growth of any one or more of a tumour, satellite lesion or metastatic lesion of a subject, the method comprising:

dosing the tumour, satellite lesion or metastatic lesion with a composition comprising thermal neutron absorbing nuclides, in the absence of a separate proton-absorbing substance provided to the subject; and

irradiating nuclei in the subject with a beam of particles consisting of any one or more of protons, deuterons, tritons or heavy ions, thereby producing neutrons in the subject through non-elastic collisions within the subject between the nuclei and the particles;

wherein the neutron absorbing nuclides absorb neutrons produced in the non-elastic collisions, thereby producing capture products or fragments that irradiate the tumour, satellite lesion or metastatic lesion.

10. The method as claimed in claim 9 , wherein the beam comprises protons, 4 He, 10 C, 11 C, 12 C, 15 O, 16 O, highly energetic protons or heavy ions.

11. The method as claimed in claim 9 , further comprising providing the thermal neutron absorbing nuclides in the form of a composition containing 10 B or 157 Gd.

12. The method as claimed in claim 11 , wherein the composition is preferentially absorbed by the tumour, satellite lesion or intracranial metastatic lesion.

13. The method as claimed in claim 9 , wherein the capture products or fragments comprise energetic charged particles of high relative biological effectiveness or other energetic charged particles.

14. The method as claimed in claim 9 , wherein said beam irradiates matter along its path in a spot scanning manner, a uniform scanning manner, a fast scanning manner, raster scanning manner, or a passively scattered manner.

15. The method as claimed in claim 9 , wherein the beam has a Bragg peak that is outside the subject.

16. A computer-implemented method of determining parameters for particle therapy of a subject, the method comprising:

modelling or simulating, based on a set of default or selected parameters:

a) irradiation of nuclei in the subject with a beam of primary particles consisting of any one or more of protons, deuterons, tritons or heavy ions;

b) production of neutrons in the subject through non-elastic collisions within the subject between the nuclei in or adjacent to the target volume and the primary particles, in the absence of a separate proton-absorbing substance provided to the subject; and

c) production of capture products or fragments released as a result of the neutron capture and nuclear reactions between at least one high neutron cross section agent located in or adjacent to a target volume and the thermal neutrons produced from the non-elastic collisions within the subject between the nuclei and the primary particles;

determining a difference between the production of the capture products or fragments with either (i) a predetermined template or desired production of the capture products or fragments, or (ii) empirical reaction validation data; and

generating a modified set of parameters according to the difference.

17. The method as claimed in claim 16 , wherein the modelling further comprises:

modelling irradiation of a tumour or a portion thereof, one or more satellite lesions or one or more metastatic lesions, or other tissue, within or adjacent to the target volume by the capture products or fragments; or

locating a composition comprising the thermal neutron absorbing nuclides in the target volume; or

modelling or simulating the target volume as PMMA (poly(methyl methacrylate)) or other tissue equivalent material.

18. The method as claimed in claim 16 , wherein the parameters comprise any one or more of:

i) duration of the irradiation;

ii) composition of the beam;

iii) energy of the particles of the beam;

iv) peak radiobiological effectiveness of the particles of the beam;

v) physical dose deposition of the particles of the beam;

vi) the composition that comprises thermal neutron absorbing nuclides;

vii) concentration of the composition that comprises thermal neutron absorbing nuclides;

viii) spatial distribution of the composition that comprises thermal neutron absorbing nuclides;

ix) fluence of the neutrons produced in the subject through the non-elastic collisions;

x) target volume position relative to the beam; or

xi) ion specific radiobiological efficacy.

19. The method as claimed in claim 16 , further comprising modelling or simulating the beam so as to have a Bragg peak that is outside of the subject.

20. A non-transitory computer-readable medium, comprising computer software configured to, when executed by one or more processors, implement the method of determining parameters for particle therapy according to claim 16 .

21. A control system for controlling an irradiation system, wherein:

the irradiation system provides a particle beam of accelerated particles comprising any one or more of protons, deuterons, tritons or heavy ions; and

the control system includes or is configured to access an irradiation program for implementing a predetermined irradiation of a target volume, the predetermined irradiation comprising:

irradiating nuclei of a subject with the particle beam, thereby prompting production of neutrons in the subject through non-elastic collisions within the subject between the nuclei and the particles, whereby thermal neutron absorbing nuclides provided before irradiation at or adjacent to the target volume, in the absence of a separate proton-absorbing substance provided to the subject, absorb neutrons produced in the non-elastic collisions, thereby producing capture products or fragments that irradiate the target volume.

22. The control system as claimed in claim 21 , comprising:

a particle supply controller configured to control a particle source of the irradiation system, the particle source supplying the particles;

an accelerator controller configured to control an accelerator of the irradiation system, the accelerator providing the particle beam by accelerating the particles;

a beam steerer for controlling one or more beam steering units configured to direct the particle beam; and

an extraction controller for controlling extraction of the accelerated particles from the accelerator.

23. The control system as claimed in claim 21 , further comprising a treatment planning system (TPS) configured to determine the irradiation program.

24. The control system as claimed in claim 21 , wherein the control system is operable so that the beam has a Bragg peak that is outside the subject.

25. An irradiation system, comprising:

a particle source for supplying primary particles comprising any one or more of protons, deuterons, tritons or heavy ions;

an accelerator for providing a particle beam by accelerating the particles;

an extraction beamline for extracting the particle beam from the accelerator;

one or more beam steering units configured to direct the particle beam; and

a control system as claimed in claim 21 .

26. The irradiation system as claimed in claim 25 , wherein the irradiation program, or a set of parameters employed thereby, is adapted or personalized for a specific target volume or subject.