Particle therapy system, dose distribution evaluation system, and method for operating particle therapy system

Patent metadata

Field	Value
Publication number	US-2021393985-A1
Application number	US-201917289346-A
Country	US
Kind code	A1
Filing date	Nov 15, 2019
Priority date	Dec 25, 2018
Publication date	Dec 23, 2021
Grant date	—

Abstract

A proton beam therapy system 1 includes an irradiation nozzle 25 for irradiating a target 31A with a particle beam, a proton beam irradiation control system 41 that controls the irradiation nozzle 25, a dose monitor 27B that measures an irradiation amount of the particle beam emitted to the target 31A, a position monitor 27A that measures a position of the particle beam emitted to the target 31A, and a dose distribution evaluation system during irradiation 55 that calculates a dose distribution of the particle beam emitted to the target 31A during irradiation. This system supports a medical staff to quickly and appropriately make an intervention determination for treatment such as discontinuation of particle therapy, a change in conditions thereof, or the like in the process of particle irradiation.

First claim

1 . A particle therapy system, comprising:
a particle irradiation system for irradiating a target with a particle beam; an irradiation control system that controls the particle irradiation system; an irradiation amount measurement instrument that measures an irradiation amount of the particle beam emitted to the target; an irradiation position measurement instrument that measures a position of the particle beam emitted to the target; a dose calculation system that calculates an actual dose distribution emitted to the target by using measurement data of the irradiation amount measurement instrument and the irradiation position measurement instrument; a display system that displays an obtained dose distribution; and a dose calculation control system that sets a timing for calculating the actual dose distribution and controls a calculation state of the actual dose distribution, wherein the dose calculation system calculates the actual dose distribution during irradiation based upon a calculation interval set by the dose calculation control system.

2 . The particle therapy system according to claim 1 , further comprising:
an irradiation time recording unit configured to record irradiation time at which the particle beam is emitted; a tracking target position measurement unit configured to measure a position of a tracking target being irradiated with the particle beam; a tracking time recording unit configured to record tracking time when the position of the tracking target is measured; and a moving body tracking control system that determines whether a position of the target is within a predetermined range based upon the position of the tracking target measured by the tracking target position measurement unit, and that outputs a signal for permitting extraction of the particle beam to the irradiation control system when determining that the position of the target is within the range, wherein the dose calculation system calculates the position of the tracking target being irradiated with the particle beam, and the irradiation amount and irradiation position of the particle beam then by synchronizing the irradiation time and the tracking time, and the irradiation control system controls the particle beam based upon the signal generated by the moving body tracking control system.

3 . The particle therapy system according to claim 1 , wherein
the dose calculation system calculates an estimated actual dose distribution as a dose distribution formed by currently ongoing irradiation based upon the actual dose distribution, and displays the estimated actual dose distribution on the display system.

4 . The particle therapy system according to claim 3 , wherein
the dose calculation system calculates the estimated actual dose distribution by calculating a differential dose distribution between a planned dose distribution and the actual dose distribution at the calculation interval recorded in an irradiation plan for each calculation interval set by the dose calculation control system, and by integrating the differential dose distribution for each calculation interval with respect to the planned dose distribution formed by the currently ongoing irradiation.

5 . The particle therapy system according to claim 4 , wherein
the dose calculation system further displays a dose evaluation index calculated from the estimated actual dose distribution on the display system.

6 . The particle therapy system according to claim 4 , wherein
the dose calculation system further compares the estimated actual dose distribution and the planned dose distribution formed by the currently ongoing irradiation, and displays a comparison result on the display system.

7 . The particle therapy system according to claim 5 , wherein
the dose calculation system further compares the dose evaluation index and a planned dose evaluation index calculated from the planned dose distribution, and display a comparison result on the display system.

8 . The particle therapy system according to claim 1 , further comprising:
an irradiation sequence division system that divides an irradiation sequence into a plurality of sequences in repaint unit.

9 . The particle therapy system according to claim 2 , wherein
the dose calculation system uses, as an X-ray CT image for specifying the position of the target used when calculating the actual dose distribution, an X-ray CBCT image imaged by the tracking target position measurement unit before and after irradiation of the particle beam or a planned CT image deformed according to the X-ray CT image.

10 . The particle therapy system according to claim 1 , wherein
the dose calculation system can select a mode in which irradiation of the particle beam is stopped until calculation of the actual dose distribution is completed, and a mode in which the irradiation of the particle beam is continuously performed even though the calculation of the actual dose distribution is not completed in cooperation with the irradiation control system.

11 . A dose distribution evaluation system that calculates a dose distribution of a particle beam emitted to a target during irradiation, the system comprising:
a dose calculation system that calculates an actual dose distribution emitted to the target by using measurement data of an irradiation amount measurement instrument that measures an irradiation amount of the particle beam emitted to the target and an irradiation position measurement instrument that measures a position of the particle beam emitted to the target; a display system that displays the obtained dose distribution; and a dose calculation control system that sets a timing for calculating the actual dose distribution, and controls a calculation state of the actual dose distribution, wherein the dose calculation system calculates an actual dose distribution during irradiation based upon a calculation interval set by the dose calculation control system.

12 . A method for operating a particle therapy system including a particle irradiation system for irradiating a target with a particle beam, an irradiation control system that controls the particle irradiation system, an irradiation amount measurement instrument that measures an irradiation amount of the particle beam emitted to the target, and an irradiation position measurement instrument that measures a position of the particle beam emitted to the target, the method comprising:
calculating, by a dose calculation system, an actual dose distribution emitted to the target by using measurement data of the irradiation amount measurement instrument and the irradiation position measurement instrument; displaying, by a display system, the obtained actual dose distribution; setting, by a dose calculation control system, a timing for calculating the actual dose distribution, and controlling, by the dose calculation control system, a calculation state of the actual dose distribution; and calculating, by the dose calculation system, an actual dose distribution during irradiation based upon a calculation interval set by the dose calculation control system.

13 . The method for operating the particle therapy system according to claim 12 , further comprising:
recording, by an irradiation time recording unit, irradiation time at which the particle beam is emitted; measuring, by a tracking target position measurement unit, a position of a tracking target being irradiated with the particle beam; recording, by a tracking time recording unit, tracking time when the position of the tracking target is measured; determining, by a moving body tracking control system, whether a position of the target is wit

Assignees

• Hitachi Ltd
• Univ Hokkaido Nat Univ Corp

Inventors

• Hirayama Shusuke
• FUJIMOTO Rintarou
• Umezawa Masumi
• Fujii Yuusuke
• Kobashi Keiji
• Matsuura Taeko
• Shimizu Shinichi

Classifications

• G01T1/02

  Dosimeters (G01T1/15 takes precedence) · CPC title

• A61N2005/1087

  Ions; Protons · CPC title

• A61N5/1071 Primary

  for verifying the dose delivered by the treatment plan · CPC title

• A61N5/1067

  in real time, i.e. during treatment · CPC title

• A61N2005/1061

  using an x-ray imaging system having a separate imaging source · CPC title