# US 10,946,220 B2 · Method of providing rotational radiation therapy using particles

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- Number: US 10,946,220 B2
- Document ID: US10946220B2
- Status: Granted
- Kind: B2
- Application number: 16/290,372
- Filed: 2019-03-01
- Published: 2020-09-03
- Granted: 2021-03-16
- Earliest claimed: 2019-03-01
- Assignees: Elekta Limited
- Applicants: Elekta, Inc.
- Inventors: Stuart Julian Swerdloff
- Web page: https://patentgrep.com/patent/US10946220B2

## CPC

- A61N 5/103: {Treatment planning systems}
- A61N 5/1043: {Scanning the radiation beam, e.g. spot scanning or raster scanning}
- A61N 5/1047: {with movement of the radiation head during application of radiation, e.g. for intensity modulated arc therapy or IMAT}
- A61N 5/1049: {for verifying the position of the patient with respect to the radiation beam}
- A61N 5/1067: {in real time, i.e. during treatment}
- A61N 5/1081: {Rotating beam systems with a specific mechanical construction, e.g. gantries}
- A61N 5/1071: {for verifying the dose delivered by the treatment plan}
- A61N 2005/1052: {using positron emission tomography [PET] single photon emission computer tomography [SPECT] imaging}
- A61N 2005/1061: {using an x-ray imaging system having a separate imaging source}
- A61N 2005/1087: {Ions; Protons}
- A61N: ELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY (measurement of bioelectric currents A61B; surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body A61B18/00; anaesthetic apparatus in general A61M; incandescent lamps H01K; infrared radiators for heating H05B)

## Abstract

Techniques are described herein for delivering a particle beam composed of a plurality of beamlets from a continuously rotating gantry towards a target, by determining a plurality of predefined spots on the target and configuring them into a set of smaller spots on the outside of the target and a set of larger spots on the inside of the target, optimizing the delivery of the rotating particle beam such that the inside edge and the outside edge of the arc of the rotating beam are delivered to the spots located at the center of the target, and the central component of the arc of the beam is delivered to the spots located at the outside of the target.

## Claims

### Claim 1

A method of delivering a plurality of particle beams from a continuously rotating gantry towards a target, the method comprising:
continuously delivering successive particle beams of the plurality of particle beams as the gantry rotates, wherein each particle beam of the successive particle beams has an associated arc, with a center of the associated arc corresponding to a particular gantry angle for each particle beam;
for a respective particle beam of the successive particle beams, delivering a plurality of beamlets from a beginning of a respective arc to an end of the respective arc;
for a respective gantry angle, determining a plurality of predefined spots in the target for the respective gantry angle, wherein the plurality of predefined spots are configured in a spiral pattern;
ordering the plurality of predefined spots in the spiral pattern from those closest to an isocentric axis for the respective gantry angle to those most distant from the isocentric axis; and
wherein delivering the successive particle beams includes delivering the plurality of beamlets for the respective particle beam according to the spiral pattern of the plurality of predefined spots.

### Claim 2 (depends on 1)

The method of claim 1, wherein the plurality of beamlets are delivered in a clockwise configuration followed by a counter-clockwise configuration.

### Claim 3 (depends on 1)

The method of claim 1, wherein a spot of the plurality of predefined spots and a beamlet of the plurality of beamlets are equivalent.

### Claim 4 (depends on 1)

The method of claim 1, wherein the plurality of predefined spots are contiguously located.

### Claim 5 (depends on 1)

The method of claim 1, wherein delivering the plurality of beamlets comprises delivering the plurality of beamlets from a position inside the target to a position on an outside edge of the target.

### Claim 6 (depends on 1)

The method of claim 1, wherein delivering the plurality of beamlets further comprises delivering the plurality of beamlets from a position on an outside edge of the target to a position inside the target.

### Claim 7 (depends on 1)

The method of claim 1, wherein spots of the plurality of predefined spots that are located at an outside edge of the target have a smaller diameter than spots of the plurality of predefined spots located at a position inside the target.

### Claim 8 (depends on 7)

The method of claim 7, wherein beamlets associated with larger diameter spots have a greater dose than the beamlets associated with the smaller diameter spots.

### Claim 9 (depends on 8)

The method of claim 8, wherein intensity modulation of the larger diameter spots is greater than the smaller diameter spots.

### Claim 10 (depends on 1)

The method of claim 1, wherein delivering the plurality of beamlets further comprises a single transition between spots of varying size.

### Claim 11 (depends on 1)

The method of claim 1, wherein a spot of the plurality of predefined spots comprises a location.

### Claim 12 (depends on 11)

The method of claim 11, wherein the spot of the plurality of predefined spots is configured to include a diameter of a beamlet delivered to the location.

### Claim 13 (depends on 11)

The method of claim 11, wherein a user selects a spot size for the location.

### Claim 14 (depends on 1)

The method of claim 1, wherein the particle beam comprises at least one of a plurality of protons, carbon-ions, ions, pions, or positively charged particles.

### Claim 15

A non-transitory machine-readable medium including instructions for delivering a plurality of particle beams from a continuously rotating gantry towards a target, which when executed by a processor, cause the processor to:
determine a plurality of spots in the target for a gantry angle, wherein the plurality of spots are configured in a spiral pattern;
order the plurality of spots in the spiral pattern from those closest to an isocentric axis for the gantry angle to those most distant from the isocentric axis; and
continuously deliver the plurality of particle beams as the gantry rotates by delivering a plurality of beamlets for each particle beam of the plurality of particle beams from a beginning of a respective arc to an end of the respective arc according to the spiral pattern of the plurality of spots, wherein a center of the respective arc corresponds to a particular gantry angle for a respective particle beam.

### Claim 16 (depends on 15)

The machine-readable medium of claim 15, wherein the plurality of beamlets are delivered in a clockwise configuration followed by a counter-clockwise configuration.

### Claim 17 (depends on 15)

The machine-readable medium of claim 15, wherein the plurality of spots are contiguously located.

### Claim 18 (depends on 15)

The machine-readable medium of claim 15, wherein spots of the plurality of spots that are located at an outside edge of the target have a smaller diameter than spots of the plurality of predefined spots located at a position inside the target, wherein beamlets associated with larger diameter spots have a greater dose than the beamlets associated with the smaller diameter spots, and wherein intensity modulation of the larger diameter spots is greater than the smaller diameter spots.

### Claim 19 (depends on 15)

The machine-readable medium of claim 15, wherein delivering the plurality of beamlets further comprises a single transition between spots of varying size.

### Claim 20 (depends on 15)

The machine-readable medium of claim 15, wherein the particle beam comprises at least one of a plurality of protons, carbon-ions, ions, pions, or positively charged particles.

### Claim 21

A system for delivering a plurality of particle beams from a continuously rotating gantry towards a target, the system comprising:
an ion source configured to provide a stream of particles to an injector, the injector configured to accelerate the stream of particles;
an accelerator configured to further accelerate the stream of particles and provide energy to the stream of particles, the energy corresponding to a delivery depth within tissue;
an energy selector configured to select energies of the stream of particles to be delivered;
a plurality of bending magnets configured to transport the stream of particles into a radiation therapy delivery room;
a plurality of scanning magnets configured to shape the stream of particles according to a target;
a snout configured to:
continuously deliver successive particle beams of the stream of particles as the gantry rotates, wherein each particle beam of the successive particle beams has an associated arc, with a center of the associated arc corresponding to a particular gantry angle for each particle beam;
for a respective particle beam of the successive particle beams, deliver a plurality of beamlets from a beginning of a respective arc to an end of the respective arc; and
a processor configured to:
for a respective gantry angle, determine a plurality of predefined spots in the target for the respective gantry angle, wherein the plurality of predefined spots are configured in a spiral pattern;
order the plurality of predefined spots in the spiral pattern from those closest to an isocentric axis for the respective gantry angle to those most distant from the isocentric axis; and
wherein delivery of the successive particle beams includes delivery of the plurality of beamlets for the respective particle beam according to the spiral pattern of the plurality of predefined spots.

### Claim 22 (depends on 21)

The system of claim 21, wherein the particle beam comprises at least one of a plurality of protons, carbon-ions, ions, pions, or positively charged particles.

### Claim 23 (depends on 21)

The system of claim 21, wherein the plurality of beamlets are delivered in a clockwise configuration followed by a counter-clockwise configuration.

### Claim 24 (depends on 21)

The system of claim 21, wherein a spot of the plurality of predefined spots and a beamlet of the plurality of beamlets are equivalent.

### Claim 25 (depends on 21)

The system of claim 21, wherein the plurality of predefined spots are contiguously located.

### Claim 26 (depends on 21)

The system of claim 21, wherein to deliver the plurality of beamlets, the snout is further configured to deliver the plurality of beamlets from a position inside the target to a position on an outside edge of the target.

### Claim 27 (depends on 21)

The system of claim 21, wherein to deliver the plurality of beamlets, the snout is further configured to deliver the plurality of beamlets from a position on an outside edge of the target to a position inside the target.

### Claim 28 (depends on 21)

The system of claim 21, wherein spots of the plurality of predefined spots that are located at an outside edge of the target have a smaller diameter than spots of the plurality of predefined spots located at a position inside the target.

### Claim 29 (depends on 28)

The system of claim 28, wherein beamlets associated with larger diameter spots have a greater dose than the beamlets associated with the smaller diameter spots.

### Claim 30 (depends on 29)

The system of claim 29, wherein intensity modulation of the larger diameter spots is greater than the smaller diameter spots.

### Claim 31 (depends on 21)

The system of claim 21, wherein to deliver the plurality of beamlets, the snout is further configured to deliver the plurality of beamlets with a single transition between spots of varying size.

### Claim 32 (depends on 21)

The system of claim 21, wherein a spot of the plurality of predefined spots comprises a location.

### Claim 33 (depends on 32)

The system of claim 32, wherein the spot of the plurality of predefined spots is configured to include a diameter of a beamlet delivered to the location.

### Claim 34 (depends on 32)

The system of claim 32, wherein the processor is further configured to receive a user selection of a spot size for the location.