WO2013016759A1

WO2013016759A1 - An image-guided radiation therapy assembly

Info

Publication number: WO2013016759A1
Application number: PCT/AU2012/000862
Authority: WO
Inventors: Paul Keall
Original assignee: Paul Keall
Priority date: 2011-07-29
Filing date: 2012-07-18
Publication date: 2013-02-07
Also published as: CN103764039A; CN103764039B; AU2012289817B2; AU2012289817A1

Abstract

An imaging assembly (10) including a base (11) to which there is a fixed a housing (14) within which there is located a radiation source such as a linear accelerator (15). The radiation source provides a beam that extends longitudinally along a predetermined path provided by an axis (16). Supported on the base (11) is a couch assembly (21) that is movable longitudinally as well as being angularly movable about the longitudinal axis (26) of the couch assembly (21).

Description

AN IMAGE-GUIDED RADIATION THERAPY ASSEMBLY

Technical Field

The present invention relates to radiation imaging and therapy apparatus and systems.

Background of the Invention

Radiation therapy is indicated for 53% of cancer patients. However, this number is typically lower in rural areas and developing countries, due in part to the significant cost of purchasing and maintaining radiation therapy equipment and the high construction cost of large bunkers need for the current treatment paradigm, in which the treatment unit rotates around the patient.

Described in USA Patent Specifications 3848132, 3708662, 4651007, 7103930 and USA Patent Publication US2003/0202631 are radiation imaging and therapy apparatus and systems. These apparatus suffer the above disadvantages.

Disclosed in USA Patent 3585386 and International Patent Publication

WO2009/076483 are patient support apparatus. These apparatus are designed to perform specific tasks and not adapted for radiation imaging and therapy apparatus.

Disclosed in Japanese Patent JP11309220 and French Patent FR2647332 are radiation imaging and therapy apparatus, however these devices also suffer from the above

disadvantages.

These known radiation therapy and imaging systems and apparatus have a number of disadvantages including size of the apparatus, complexity of shielding, expense of

construction, complexity, stability relating to the moving beam source, maintenance, costly servicing and life of the apparatus can also be of concern.

Object of the Invention

It is the object of the present invention to overcome or substantially ameliorate at least one of the above disadvantages. Summary of the Invention

There is disclosed herein an assembly to subject a patient to a radiation beam, the assembly including:

a base to be supported on a floor surface;

a radiation source to provide the beam, the source being mounted in the base so as to be fixed thereto and to project the beam along a path;

a patient couch assembly mounted on the base for movement relative thereto, the couch providing a longitudinally extending surface upon which the patient is to be supported and providing a longitudinal couch axis said surface being longitudinally elongated, the couch assembly being movable so that said surface intersects said path; and

a motor and support assembly operatively associated with the couch assembly and base to cause said movement, the movement including movement longitudinally of said axis and angular movement about said axis.

Preferably, said axis has a horizontal major direction of extension.

Preferably, the surface is locatable in a generally horizontal orientation.

Preferably, said angular movement includes 180° in either angular direction about said axis.

Preferably, said angular movement is limited to 180° in either angular direction about said axis.

Preferably, said path is generally vertically oriented.

Preferably, said path is located in a plane within which said axis is located, and said axis is inclined to the vertical by an acute angle.

Preferably, the assembly further includes an x-ray source and a detector, the x-ray source and detector being mounted in the base and on opposite sides of said couch so that a patient can be located between the x-ray source and detector. There is further disclosed herein an assembly to subject a patient to a radiation beam, the assembly including:

a base to be supported on a floor surface;

a patient couch assembly mounted on the base for movement relative thereto, the couch providing a longitudinally extending surface upon which the patient is to be supported and providing a longitudinal couch axis, the couch assembly being movable longitudinally relative to said axis and angularly relative to said axis so that said surface intersects said path; a motor and support assembly operatively associated with the couch assembly and base to cause said movement, the movement including movement longitudinally relative to said axis and angular movement relative to said axis; and wherein

the surface is locatable in a generally horizontal orientation, with the angular movement including 180° in either angular direction relative to said axis from said horizontal orientation.

Preferably, said axis has a major direction of extension that is horizontal.

Preferably, said path is generally perpendicular to said axis.

Preferably, said path is inclined to said axis by an acute angle.

Preferably, said radiation source includes a housing, with said housing being fixed to said base so as to be fixed stationary relative to said base..

Brief Description of the Drawings

A preferred form of the present invention will now be described by way of example with reference to the accompanying drawings wherein:

Figure 1 is a schematic isometric view of an image-guided radio therapy assembly;

Figure 2 is a schematic further isometric view of the assembly of Figure 1 ; Figure 3 is a schematic parts sectioned isometric view of the assembly of Figures 1 and 2;

Figure 4 is a schematic isometric view of a modification of a couch assembly employed in the assembly of Figures 1 to 3;

Figure 5 is a further schematic isometric view of the couch assembly of Figure 4;

Figure 6 is a schematic side elevation of the couch assembly of Figures 4 and 5;

Figure 7 is a schematic top plan view of the couch assembly of Figures 4 and 5; and

Figure 8 is a schematic end elevation of the couch assembly of Figures 4 and 5.

Detailed Description of the Preferred Embodiment

In the accompanying drawings there is schematically depicted an image-guided radiation therapy and/or imaging assembly 10. The assembly 10 includes a base 11 that includes a pedestal 12 and a tubular portion 13. The tubular portion 13 is fixed to the pedestal 12 so as to be supported thereby in a stable manner. Fixed to and extending upwardly of the tubular portion 13 is a housing 14 within which there is located a radiation source such as a linear accelerator 15. The housing 14 is fixed in a stationary position in relation to the base 1 1. In this embodiment the accelerator 15 provides a beam that extends longitudinally along a predetermined path providing the axis 16. Preferably, the axis 16 is generally upright, more preferably vertical. However it should be appreciated the housing 14 may not be positioned so as to be vertically oriented. As a particular example, the linear accelerator 15 may have its axis 16 inclined by an acute angle to the vertical. The axis 16 is located in a plane containing the axis 16.

As an alternative to the above described linear accelerator 15, a cobalt source or particle beams such as proton and carbon therapy beams may be employed.

Also mounted within the housing 14 is a multileaf collimator 17. Preferably the multileaf collimator 17 is used to shape the radiation beam and adapt this as needed to the changing beam-patient treatment angle and account for any detector tumour and/or normal tissue changes and motion by adaptation. Other beam shaping devices may be used.

Mounted in one longitudinally extending side of the tubular portion 13 is a kVx-ray detector 18, while in the opposite longitudinally extending side portion is a kVx-ray source 19.

Located in a lower part of the tubular portion 13 or the pedestal 12 is an electronic portal imaging device 20. Other devices may be used. The device 20 is located so as to intersect the axis 16 and preferably is generally planar and normal with respect to the axis 16.

Mounted in the tubular portion 13 is a couch assembly 21. The couch assembly 21 is adapted to support a patient 22. Preferably the couch assembly 22 would include a couch base 25 that is longitudinally elongated and receives a full length vacuum moulded support 23 placed below the patient 22, with the patient 22 in a surpine position. A retaining sheet 24 or possibly a further moulded member is provided and secured to the base 25 to aid in retaining the patient 22 firmly against the support 23.

The detector 18 and source 19 are located on opposite sides of the couch assembly 21 so that the patient is also locatable between the detector 18 and source 19.

The base 25 provides a longitudinal axis 26 that preferably extends generally centrally longitudinally through the patient 22. Preferably, the axis 26 has a major direction of extension that is horizontal. Preferably, the axis 26 is generally horizontal. The couch assembly 21 is supported by the tubular portion 13 to provide for longitudinal movement of the couch base 25 longitudinal of the axis 26, as well as angular movement about the axis 26. Preferably the couch base 25 is movable angularly about the axis 26 through 180° in either direction from the position at which the couch base 25 is generally horizontally oriented. The couch base 25 may actually be rotatable through 360°. Preferably the axis 26 intersects and is normal to the axis 16, therefore the axis 16 intersects the couch base 25 and the patient 22.

As a further modification of the above described preferred embodiment, the couch assembly 21 and base 11 may be modified to provide for angular movement about a generally horizontal axis normal to the axis 26 and/or a generally vertical axis normal to the axis 26. The linear accelerator 15 as mentioned above is vertically mounted, and is used to create the radiation treatment beam or an image beam.

The multileaf collimator 17 is used to shape the treatment beam, so that the beam shaping can occur in real-time to account for anatomic changes of the tumour and normal tissue due to physiological processes and/or couch rotation. As a particular example, the method employed can adapt the treatment beam to optimally account for tumour and normal tissue translation, rotation and deformation.

Many image guidance and real-time monitoring systems (broadly referred to as image guidance systems) are currently available that can be used to detect anatomic (and potentially physiologic) patient changes from day-to-day, during a treatment and during patient rotation. These include systems from Calypso, VisionRT, Navotek, MicroPos, RadPos, Accuray, BrainLab as well as those developed by single modality or combinations of kV, MV and optical methods with and without implanted markets. The x-ray imager could include tomosythesis options, by various means as well as full cone beam capabilities. See also International Patent Application PCT/US2010/001944.

The electronic portal imaging device 20 is preferably employed to image the treatment beam and patient anatomy including any radio-opaque implanted markers that may be present. The device 20 can be used to verify the spatial and dosimetric characteristics of the treatment delivery to the patient anatomy that may be changing during the treatment. There are available real-time beam-targeting correction systems such as DMLC tracking, robotically mounted linear accelerators, programmable couches and gimballed linear accelerators.

In respect of the detector 18 and source 19, they may be an image-guidance device that is a kilovoltage x-ray source and detectorV They can be used for pre-treatment planar and volumetric imaging as well as intra-treatment monitoring of anatomy, for 3D trajectory on the individual points on or inside the body, to construction of the entire patient anatomy in realtime.

In Figures 4 to 8 there is schematically depicted a couch assembly 21. In this embodiment the couch assembly 21 includes a support frame 30 that would be mounted internally of the tubular portion 13 so as to be stationary with respect thereto. Mounted on the support frame 30 is a carriage 31. The carriage 31 is supported by rollers or wheels 32 so as to provide for movement of the carriage longitudinally of the axis 26. Preferably, at least one of the wheels 32 is driven by a belt 33. The belt 33 is in turn driven by an electric motor and gear box assembly 34. The motor 34 is operated so that the carriage 32 can be moved in either direction 35, that is a direction longitudinally of the axis 26.

The carriage 31 includes a pair of upwardly extending end frames 36 that rotatably support a pair of shafts 37. The shafts 37 are fixed to a couch base 38 upon which the patient 22 rests. The shafts 37 are at each end of the base 38 to provide for angular movement of the base 38 about the axis 26. Fixed to one of the shafts 37 is a pulley 39 engaged by a belt 40. The belt 40 is in turn driven by an electric motor and gear box assembly 41. By operation of the motor and gear box assembly 41 , the base 38 can be moved angularly about the axis 26 as described above.

When the base 38 is inclined, to ensure that the patient 22 is retained in a fixed position on the base 38, there is provided a plurality of retaining straps (bands) 42 that are movable between a position engaged with the base 38 and holding the patient 22 in position against the base 38, to a position at which they provide space for the patient 22 to be moved from or delivered to the base 38.

The above described preferred embodiment provides a number of advantages including reduced spaced as the patient is rotated, with the base 11 and beam source (linear accelerator) are stationary, that is with the beam source not movable or adjustable by movement relative to the base 1 1.

A further advantage is that less shielding is required. Only one primary shield is required, rather than the usual shielding needed for a conventional bunker where the beam source is moved angularly. This advantage can be enhanced if the floor is used for a primary shielding.

A still further advantage is cost of the assembly 10. Because the beam source is stationary, complex apparatus is not required to move the beam source.

A still further advantage is stability. Since the beam source is stationary, stability problems are substantially ameliorated. Again since the beam source is stationary, there are less moving parts thereby reducing maintenance of the assembly and prolonging the life of the assembly. r

Yet a further advantage is safety. Since there are far less moving parts and since the beam source is stationary, there are fewer safety issues to be addressed.

Claims

1. An assembly to subject a patient to a radiation beam, the assembly including:

a base to be supported on a floor surface;

2. The assembly of claim 1, wherein said axis has a horizontal major direction of extension.

3. The assembly of claim 1 or 2, wherein the surface is locatable in a generally horizontal orientation.

4. The assembly of claim 1, 2 or 3, wherein said angular movement includes 180° in either angular direction about said axis.

5. The assembly of claim 4, wherein said angular movement is limited to 180° in either angular direction about said axis.

6. The assembly of any one of claims 1 to 5, wherein said path is generally vertically oriented.

7. The assembly of any one of claims 1 to 5, wherein said path is located in a plane within which said axis is located, and said axis is inclined to the vertical by an acute angle.

8. The assembly of any one of claims 1 to 7, further including an x-ray source and a detector, the x-ray source and detector being mounted in the base and on opposite sides of said couch so that a patient can be located between the x-ray source and detector.

9. An assembly to subject a patient to a radiation beam, the assembly including:

a base to be supported on a floor surface;

10. The assembly of claim 9, wherein said axis has a major direction of extension that is horizontal.

1 1. The assembly of claim 9 or 10, wherein said path is generally perpendicular to said axis.

12. The assembly of claim 11, wherein said path is inclined to said axis by an acute angle.

13. The assembly of any one of claims 1 to 12, wherein said radiation source includes a housing, with said housing being fixed to said base so as to be fixed stationary relative to said base.