Dispersive force corrected gantry based radiation treatment apparatus and method of use thereof

Patent metadata

Field	Value
Publication number	US-2017216632-A1
Application number	US-201715489396-A
Country	US
Kind code	A1
Filing date	Apr 17, 2017
Priority date	Apr 16, 2010
Publication date	Aug 3, 2017
Grant date	—

Abstract

The invention comprises a method and apparatus for directing a positively charged particle beam to a tumor of a patient, comprising the steps of: (1) transporting the positively charged particle beam sequentially from a synchrotron, through a beam transport line, and through a nozzle system toward the tumor, the beam transport line comprising a rotatable beamline section; (2) pre-rotating the positively charged particle beam using a solenoid, the solenoid positioned in the beam transport line between the synchrotron and the rotatable beamline section; and (3) rotating the rotatable beamline section, where the step of pre-rotating maintains a geometric relationship between a radial cross-section of the positively charged particle beam and magnet surfaces in the rotatable beamline section as a function of rotation of the rotatable beamline section, which reduces otherwise changed dispersive forces as the rotatable beamline is positioned in separate areas about the patient.

First claim

1 . A method for directing a positively charged particle beam to a tumor of a patient, comprising the steps of:
transporting the positively charged particle beam sequentially from a synchrotron, through a beam transport line, and through a nozzle system toward the tumor, said beam transport line comprising a rotatable beamline section; pre-rotating the positively charged particle beam using a solenoid, said solenoid positioned in said beam transport line between said synchrotron and said rotatable beamline section; and rotating said rotatable beamline section.

2 . The method of claim 1 , said step of pre-rotating further comprising the step of:
maintaining a geometric relationship between a radial cross-section of the positively charged particle beam and magnet surfaces of a first magnet of said rotatable beamline section in at least three rotation positions of said rotatable beamline section.

3 . The method of claim 2 , further comprising the step of:
detecting the positively charged particle beam using a scintillation detector after transmission through the tumor.

4 . The method of claim 3 , further comprising the step of:
using a current radiation treatment plan of the tumor in control of said steps of pre-rotating and rotating.

5 . The method of claim 4 , further comprising the step of:
using a gantry system to rotate said rotatable beamline section about an axis of rotation of said gantry system.

6 . The method of claim 1 , said step of rotating further comprising the step of:
using a gantry system to rotate said rotatable beamline section about an axis of rotation of said gantry system.

7 . The method of claim 6 , said step of pre-rotating further comprising the step of:
matching a first rotation magnitude of the positively charged particle beam in said solenoid to a second rotation magnitude of said gantry system about the axis of rotation of said gantry system.

8 . The method of claim 1 , further comprising the steps of:
providing a triode extraction system, comprising:
an ion source maintained at a first potential;
an extraction electrode maintained at a third potential differing from said first potential; and
a gating electrode positioned between said ion source and said extraction electrode;
alternatingly (1) suppressing extraction of the positively charged particle beam from said ion source and (2) extracting the positively charged particle beam from said ion source through changing a second potential of said gating electrode from proximate the first potential to a value between the first potential and the third potential; and injecting the positively charged particle beam into said synchrotron.

9 . The method of claim 8 , further comprising the step of:
said steps of pre-rotating and rotating maintaining a geometrical relationship between an axial cross-section of the positively charged particle beam and a first rotatable magnet of said rotatable beamline section.

10 . The method of claim 1 , further comprising the step of:
updating, to conform with an automated update of a radiation treatment plan, both: (1) a rotation of said rotatable beamline section about an axis of rotation of said rotatable beamline section and (2) a current along a coil of said solenoid.

11 . The method of claim 10 , further comprising the step of:
adjusting the current to maintain a relative geometry of a radial cross-section of the positively charged particle beam to a nearest magnet surface of said rotatable beamline section in at least three rotation positions of said rotatable beamline section.

12 . The method of claim 1 , said step of pre-rotating further comprising the step of:
maintaining dispersive forces of at least one magnet of said rotatable beamline section on the positively charged particle beam in at least three rotation positions of said rotatable beamline section by altering a current applied to said solenoid.

13 . The method of claim 12 , further comprising the steps of:
removing a first set of positively charged particles, from said synchrotron, at a first energy using a beam extraction system, said positively charged particle beam comprising the first set of positively charged particles; providing a beam energy adjustment system, comprising:
a synchrotron gap axially crossing a circulation beam path of the positively charged particle beam in said synchrotron; and
a radio-frequency controller;
applying a potential difference across the synchrotron gap, using said radio-frequency controller, at an applied radio-frequency using said beam energy adjustment system; timing the applied radio-frequency and the potential difference to alter a remaining grouped bunch of the positively charged particle beam in said circulation beam path from the first energy to a second energy; and subsequent to said step of removing, extracting a portion of the remaining grouped bunch of the positively charged particles, from said synchrotron, at the second energy prior to reloading said synchrotron using a loading system.

14 . The method of claim 13 , further comprising the step of:
rotating the rotatable beamline section about a gantry axis of rotation using a gantry, wherein all first movable gantry elements, of said gantry, on a first side of the gantry axis of rotation comprise a first moment of force within ten percent of a second moment of force of all second movable gantry elements, of said gantry, on a second side of the gantry axis of rotation opposite the first side.

15 . An apparatus for directing a positively charged particle beam to a tumor of a patient, comprising:
a beam transport line connected on a first end to a synchrotron and connected on a second end to a nozzle system, said beam transport line comprising a rotatable beamline section, said beam transport line configured to transport the positively charged particle beam from said synchrotron to said nozzle system; a solenoid, positioned in said beam transport line between said synchrotron and said rotatable beamline section, configured to pre-rotate the positively charged particle beam; and a gantry configured to rotate said rotatable beamline section.

16 . The apparatus of claim 15 , said gantry further comprising:
a gantry axis of rotation, wherein all first movable gantry elements, of said gantry, on a first side of the gantry axis of rotation comprise a first moment of force within ten percent of a second moment of force of all second movable gantry elements, of said gantry, on a second side of the gantry axis of rotation.

17 . The apparatus of claim 16 , said solenoid further comprising:
at least one winding coil configured to generate a magnetic field axially crossing the positively charged particle beam; and a main controller configured to apply dispersive forces to the positively charged particle beam using a current applied to said winding coil, wherein the dispersive forces rotate the positively charged particle beam to maintain a geometric relationship between a cross-sectional shape of the positively charged particle beam and a pair of magnet surfaces of a first magnet of said rotatable beamline section as a function of rotation of said nozzle system about the tumor during use.

Assignees

• Lee W Davis
• Teymurazyan Artur
• Amato Mark R
• Penfold Scott
• Bennett James P

Inventors

• Lee W Davis
• Teymurazyan Artur
• Amato Mark R
• Penfold Scott
• Bennett James P

Classifications

• A61N5/1049

  for verifying the position of the patient with respect to the radiation beam · CPC title

• A61N5/103

  Treatment planning systems · CPC title

• A61N2005/1087

  Ions; Protons · CPC title

• A61N5/1081 Primary

  Rotating beam systems with a specific mechanical construction, e.g. gantries · CPC title

• A61N2005/1052

  using positron emission tomography [PET] single photon emission computer tomography [SPECT] imaging · CPC title