Particle beam therapy system, and method for operating particle beam therapy system

Patent metadata

Field	Value
Publication number	US-2016263399-A1
Application number	US-201415029385-A
Country	US
Kind code	A1
Filing date	Oct 22, 2014
Priority date	Oct 25, 2013
Publication date	Sep 15, 2016
Grant date	—

Abstract

Visualizing a deformation amount or displacement amount of a region of interest in therapy rendered in an image upon aligning images used in radiation therapy allows for enhancing an accuracy of alignment. In a positioning system 104 , an image processing unit 201 calculates a deformation parameter using a non-rigid registration method for a region of interest having been set by a treatment planning device 101 based on a treatment plan CT image and three-dimensional tomographic image imaged for bed positioning and calculates a displacement amount parameter for a region extracted using a region extraction method. The image processing unit 201 calculates a positioning parameter representing a displacement amount of a bed based on the calculated deformation parameter and displacement amount parameter and displays the respective parameters together with an alignment image, thereby allowing for confirmation of the deformation amount and displacement amount.

First claim

1 . A radiation therapy apparatus, comprising:
an image processing unit; and a display unit, wherein the image processing unit: inputs, thereto, a treatment plan image imaged in advance as a tomographic image and information of a region of interest including a target and/or an organ at risk generated by a treatment planning device and inputs, thereto, a positioning image imaged by a tomographic imaging device for positioning for irradiation of radioactive rays; performs alignment of the treatment plan image and the positioning image; calculates a first deformation parameter and a second deformation parameter representing deformation in a whole image and deformation in a partial image, respectively, between the aligned treatment plan image and the positioning image and calculates a displacement amount parameter representing displacement from the region of interest in the treatment plan image to the region of interest in the positioning image; calculates a positioning parameter representing a position displacement amount and rotation amount of a bed based on the first and second deformation parameters and the displacement amount parameter; displays one or more of an image representing the first deformation parameter, an image representing the second deformation parameter, an image representing the displacement amount parameter, and an image representing the positioning parameter on the display unit; and outputs the positioning parameter to cause the bed to move and rotate.

2 . The radiation therapy apparatus according to claim 1 ,
wherein the image processing unit: calculates, with regard to the aligned treatment plan image and the positioning image, the first deformation parameter based on a degree of deformation of the entire positioning image relative to the treatment plan image; extracts a first region in the region of interest in the treatment plan image and a second region in the region of interest in the positioning image; and calculates the second deformation parameter based on a degree of deformation of the first region and the second region.

3 . The radiation therapy apparatus according to claim 2 ,
wherein the image processing unit: calculates, with regard to the aligned treatment plan image and the positioning image, a third deformation parameter based on a degree of deformation of the entire positioning image relative to the treatment plan image or uses the first deformation parameter as the third deformation parameter; applies the third deformation parameter to the region of interest in the treatment plan image and calculates a deformed region of interest; calculates a first characteristic region which is common to a region corresponding to the region of interest in the treatment plan image and a characteristic region in the region of interest in the treatment plan image and calculates a second characteristic region which is common to a region corresponding to the deformed region of interest in the positioning image and a characteristic region in the region of interest in the positioning image; and calculates the displacement amount parameter representing displacement with regard to the first characteristic region and the second characteristic region.

4 . The radiation therapy apparatus according to claim 3 ,
wherein a moving vector of each of centroids of the first characteristic region and second characteristic region is the displacement amount parameter or a moving vector obtained from comparison of contour outlines is the displacement amount parameter.

5 . The radiation therapy apparatus according to claim 3 ,
wherein the image processing unit calculates each of the first and second characteristic regions as a common region by means of logical add or logical multiply.

6 . The radiation therapy apparatus according to claim 1 ,
wherein the image processing unit calculates the positioning parameters representing a position displacement amount and rotation amount of the bed in six degrees of freedom using a deformation amount obtained from the first deformation parameter, a deformation amount obtained from the second deformation parameter, and a displacement amount obtained from the displacement amount parameter based on predetermined weighting and an expression.

7 . The radiation therapy apparatus according to claim 1 ,
wherein the image processing unit comprises: a deformation parameter database configured to store the first deformation parameter and the second deformation parameter; a displacement amount parameter database configured to store the displacement amount parameter; and a positioning parameter database configured to store the positioning parameter.

8 . The radiation therapy apparatus according to claim 7 ,
wherein the image processing unit obtains and displays, on the display unit, an average, dispersion, other tendencies thereof, or changes over time of one or more of a deformation amount of the region of interest, a displacement amount of the region of interest, position displacement amount and rotation amount of the bed using data accumulated in the deformation parameter database, displacement amount parameter database, and/or positioning parameter database.

9 . The radiation therapy apparatus according to claim 1 ,
wherein the image processing unit displays, on the display unit, one or more of the treatment plan image, positioning image, and a fusion image where both of the images overlap and thereby displayed.

10 . The radiation therapy apparatus according to claim 1 ,
wherein the image processing unit comprises: an image alignment unit configured to align the treatment plan image and the positioning image; a region extraction unit configured to extract the region of interest from the treatment plan image and the positioning image; a region deformation unit configured to deform a region based on the alignment result obtained from the image alignment unit; a deformation parameter calculation unit configured to calculate the first and second deformation parameters; and a displacement amount parameter calculation unit configured to calculate the displacement amount parameter based on the treatment plan image and the positioning image.

11 . A radiation therapy system, comprising:
a treatment planning device configured to generate a treatment plan image imaged in advance as a tomographic image and information of a region of interest including a target and/or an organ at risk in order to produce a treatment plan of radiation therapy; a tomographic imaging device configured to generate, as a tomographic image, a positioning image for positioning of an object of irradiation of radioactive rays; and a positioning system configured to execute bed positioning processing, the system comprising an image processing unit and a display unit, wherein the image processing unit in the positioning system: inputs, thereto, the treatment plan image and information of the region of interest generated by a treatment planning device and inputs, thereto, the positioning image imaged by the tomographic imaging device; performs alignment of the treatment plan image and the positioning image; calculates a first deformation parameter and a second deformation parameter representing deformation in a whole image and deformation in a partial image, respectively, between the aligned treatment plan image and the positioning image and calculates a displacement amount parameter representing displacement from the region of interest in the treatment plan image to the region of interest in the positioning image; calculates a positioning parameter representing a position displacement amount and rotation amount of a bed based on the first and sec

Assignees

• Hitachi Ltd

Inventors

• Matsuzaki Kazuki
• Umekawa Toru

Classifications

• A61N2005/1061

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

• A61N2005/1063

  maintaining the position when the patient is moved from an imaging to a therapy system · CPC title

• A61N5/1049

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

• A61N2005/1087

  Ions; Protons · CPC title

• A61N5/107 Primary

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