JP2001245994A - Radiation therapy device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inexpensive radiation therapy device occupying a small volume and facilitating access to patient. SOLUTION: In this radiation therapy device provided with a rotational gantry revolvable around the rotation axis 1, an irradiation field forming device 3 mounted on the rotational gantry so as to lead a particle beam to an irradiation field along a radiation axis 2 crossing the rotation axis 1, and a plurality of deflecting magnets 4a, 4b, etc., deflecting the particle beam fed along the rotation axis 1 in the radiation axis 2 direction so as to guide it to the irradiation field forming device 3, the radiation axis 2 crosses the rotation axis 1 slantingly.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radiotherapy apparatus using a particle beam such as a proton beam or a heavy particle beam, and more particularly to a radiotherapy apparatus which is inexpensive, occupies a small volume, and is easily accessible to a patient. .

[0002]

2. Description of the Related Art Conventionally, X-rays have been used for radiotherapy. In recent years, radiotherapy using proton beams or heavy ion beams has been considered. Proton beam or heavy ion beam is X
Since the irradiation dose distribution is superior to that of X-rays, there is an advantage that irradiation can be accurately performed on a tumor affected part (elimination of unnecessary irradiation to a healthy part), and there is an advantage that there are few complications. For this reason, the practical use of radiation therapy apparatuses using proton beams or heavy particle beams (hereinafter collectively referred to as particle beams) has been promoted.

[0003] An outline of a conventional radiotherapy apparatus will be described.

As shown in FIG. 5, a conventional radiotherapy apparatus has a rotating shaft (hereinafter referred to as a horizontal shaft) 5 provided horizontally.
A rotating gantry (not shown) having a ring structure rotatable 360 ° around the axis 1, and a particle beam mounted on the rotating gantry and extending along the irradiation axis 2 orthogonal to the horizontal axis 51 to a desired sectional shape and depth. And an irradiation field forming device 3 for guiding a particle beam emitted along a horizontal axis 51 from a source (not shown) to a horizontal axis 51 with respect to the horizontal axis. A deflecting magnet 4a for deflecting and a deflecting magnet 4b for deflecting the particle beam in the direction of the irradiation axis 2
Consists of

[0005] The particle beam from the radiation source is transmitted to the deflection magnet 4a.
Is deflected in the direction toward the deflection magnet 4b by
Further, the light is deflected in the direction of the irradiation axis 2 by the deflection magnet 4b and enters the irradiation field forming device 3. The irradiation field forming device 3 irradiates a desired irradiation field with a particle beam by enlarging or reducing the width of the particle beam, adjusting the intensity and distribution of the particle beam energy, and regulating the contour of the particle beam. The irradiation axis 2
The intersection of the horizontal axis 51 with the horizontal axis 51 is called an isocenter, and the particle beam passes through the isocenter regardless of the rotation angle of the rotating gantry.
The path length from the radiation source to the isocenter is constant regardless of the rotation angle of the rotating gantry.

[0006] Patient A is usually placed on a treatment bed (not shown) in a supine position (upright position), and the patient A is treated with an axis passing through the head and feet (hereinafter referred to as a body axis) substantially overlapping a horizontal axis. Receive. The particle beam is irradiated at right angles to the body axis regardless of the rotation angle of the rotating gantry. By rotating the rotating gantry, the particle beam can be emitted from an arbitrary angle in the circumferential direction of the body axis. In the radiation therapy using a particle beam, the irradiation angle is not changed while irradiating the particle beam, and the irradiation is performed at a desired irradiation angle planned in advance. In other words, one irradiation is performed only in one direction.

[0007]

This type of radiotherapy apparatus is installed in LLUMC in the United States, MGH in the United States, the National Cancer Center, and the like. These are huge, with the size of the rotating gantry being 10 m in diameter and 10 m in length.

[0008] These conventional radiotherapy devices have the drawback of being large and expensive, and this drawback has hindered their spread in the future. For example, a rotating gantry for X-ray therapy is about 2.5 cm on a side, whereas a conventional rotating gantry for particle beam therapy is very large, about 10 m on a side.

In the conventional radiotherapy apparatus, since the irradiation field forming device 3 extending in a direction perpendicular to the horizontal axis 51 is rotated around the horizontal axis 51, the space required for the rotational movement is large. Moreover, the upper left and lower left spaces in FIG. 5 cannot be used for anything. For these reasons, the volume occupied by the radiation therapy apparatus is large, and a huge space is required for the building 52 in which the radiation therapy apparatus is installed. As a result, the radiation shielding facilities in the surrounding area become large-scale, which further increases the cost. Furthermore, the conventional radiation therapy apparatus has a huge underfloor space 53 that is nearly half of the occupied volume, so that the cost of the building 52 also increases.

[0010] Further, in the conventional radiotherapy apparatus, since the treatment bed is located above the underfloor space 53, it is difficult to access the patient.

As a measure to reduce the occupied volume, it is conceivable to eliminate the ring structure of the rotating gantry and adopt a structure in which the rotating gantry is rotated around a shaft within a predetermined angle range, but the rotation is not smooth and the mechanism is complicated. Therefore, it is desirable to adopt a structure capable of rotating by 360 °.

An object of the present invention is to solve the above-mentioned problems and to provide a radiotherapy apparatus which is inexpensive, occupies a small volume, and is easily accessible to a patient.

[0013]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a rotating gantry rotatable around a rotation axis and a particle mounted on the rotation gantry along an irradiation axis intersecting the rotation axis. An irradiation field forming device that guides rays to the irradiation field,
In a radiation therapy apparatus having a plurality of deflection magnets for deflecting a particle beam supplied along a rotation axis in a direction of an irradiation axis and guiding the beam to an irradiation field forming apparatus, the irradiation axis is inclined with respect to the rotation axis. Crossed.

[0014] The rotation axis may be inclined with respect to the horizontal.

[0015] The rotation axis may be inclined by 45 ° with respect to the horizontal, and the irradiation axis may be inclined by 45 ° with respect to the rotation axis.

[0016]

An embodiment of the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 shows a first embodiment. This radiotherapy apparatus has a rotating gantry (not shown) having a ring structure rotatable 360 ° around a rotating shaft 1 inclined at 45 ° with respect to the horizontal, and mounted on the rotating gantry. An irradiation field forming device 3 for guiding a particle beam to a desired irradiation field along an irradiation axis 2 inclined at 45 °, and a particle beam emitted along a rotation axis 1 from a source (not shown) with respect to the rotation axis 1 It comprises a deflecting magnet 4a for deflecting by 45 ° and two deflecting magnets 4b and 4c for deflecting the particle beam by 90 ° toward the irradiation axis 2. These two deflecting magnets 4b and 4c deflect 45 °, respectively, and the particle beam is configured to be parallel to the rotation axis 1 between the two deflecting magnets. However, the inclination angle of the rotating shaft 1 is not limited to 45 °. The deflection angles of the deflection magnets 4a, 4b, 4c and the inclination angle of the irradiation shaft 2 are not limited to 45 °. Also, the number of deflection magnets is 3
It is not limited to a table.

The particle beam from the radiation source is transmitted to the deflection magnet 4a.
Is deflected by 45 ° in a direction toward the deflection magnet 4b, and is deflected by the deflection magnet 4b.
And is further deflected by 45 ° in the direction of the irradiation axis by the deflecting magnet 4c to enter the irradiation field forming device 3. The irradiation field forming device 3 irradiates a desired irradiation field with a particle beam by enlarging or reducing the width of the particle beam, adjusting the intensity and distribution of the particle beam energy, and regulating the contour of the particle beam. The path length from the radiation source to the isocenter is constant regardless of the rotation angle of the rotating gantry.

In this radiotherapy apparatus, the irradiation axis 2 is inclined 45 ° with respect to the rotation axis 1 and the rotation axis 1 is inclined 45 ° with respect to the horizontal, so that the irradiation axis 2 is 90 ° with respect to the horizontal.
From 0 to 0 °.

The patient A is placed on the treatment bed 5, for example,
Receiving treatment in a supine position. Therefore, the irradiation axis 2 continuously forms different solid angles from a right angle to a body axis depending on the rotation angle of the rotating gantry. By setting the rotating gantry at an arbitrary rotation angle, the particle beam can be irradiated at an arbitrary solid angle with respect to the body axis. However, this radiation therapy apparatus cannot irradiate the patient A with a particle beam from below. Therefore, for example, when a conventional radiation therapy apparatus irradiates a patient in a supine position from below with a particle beam, the radiation therapy apparatus of the present invention irradiates a patient in a prone position (prone) with a particle beam from above. The same effect is obtained by doing so. As described above, since the irradiation angle is not changed while irradiating the particle beam, such a method is possible.

In this radiotherapy apparatus, the treatment bed 5
May be movable. For example, the posture and position of the patient are arbitrarily set using a six-axis movable bed capable of three-axis linear movement and three-axis rotation movement. Thereby, an arbitrary part of the patient A can be positioned at the isocenter, and arbitrary irradiation (Coplanar irradiation and Non-Coplanar irradiation) can be performed.

The operator who performs the radiation treatment has a CT
Identify the affected area based on tomographic images etc. taken by the device, plan the irradiation angle and irradiation field so that the most effective and healthy parts are not irradiated unnecessarily, and rotate the gantry according to this irradiation angle. Is set, and the irradiation field of the irradiation field forming apparatus 3 is set.

FIG. 2 shows a radiotherapy apparatus similar to that of FIG. 1 together with a building. This radiation therapy apparatus has a deflection magnet 4a for deflecting a particle beam from a radiation source by 45 °.
And a deflection magnet 4b for deflecting the particle beam by 90 °
And irradiation field forming device 3 inclined at 45 ° with respect to rotation axis 1
And In this radiotherapy apparatus, the rotation axis 1 is inclined by 45 ° with respect to the horizontal, and the irradiation axis 2 is rotated 45 degrees with respect to the rotation axis 1.
°, the space required for the movement of the rotating gantry is substantially cubic, and can be stored in the rectangular parallelepiped space of the building 21 without wasteful space. As a result, the occupied volume is reduced to a fraction of that in the prior art shown in FIG. Since the radiation shielding facilities in the surrounding area are also small, costs can be reduced. Since the space required for the movement of the rotating gantry does not extend below the floor, the space under the floor is not required and the cost of the building can be reduced. Further, since the treatment bed is arranged on the floor, access to the patient is easy.

Thus, the radiotherapy apparatus of the present invention
It solves all of the costs, occupied volume, and patient access problems of conventional radiotherapy equipment. Further, since the rotating gantry is supported by the ring structure, smooth rotation similar to that of the related art can be obtained.

FIG. 3 shows a second embodiment. This radiation therapy apparatus is arranged around a rotation axis 1 provided horizontally at 360 °.
A rotating gantry (not shown) having a rotatable ring structure, and a particle beam mounted on the rotating gantry, for example, along the irradiation axis 2 inclined at 20 ° with respect to the rotation axis 1 to a desired irradiation field. An irradiation field forming device 3 for guiding, a deflection magnet 4a for deflecting a particle beam emitted from a source (not shown) along the rotation axis 1 so as to be inclined by 20 ° with respect to the rotation axis 1,
A deflection magnet 4b for deflecting the particle beam by 40 ° in the direction of the irradiation axis 2. However, the rotating shaft 1 does not necessarily have to be provided horizontally. Further, the inclination angle of the irradiation axis 2 is also arbitrary.

The particle beam from the radiation source is transmitted to the deflection magnet 4a.
20 ° in the direction toward the deflecting magnet 4b, and 4 ° in the direction of the irradiation axis 2 by the deflecting magnet 4b.
The light is deflected by 0 ° and enters the irradiation field forming device 3. The irradiation field forming device 3 irradiates a desired irradiation field with a particle beam by enlarging or reducing the width of the particle beam, adjusting the intensity and distribution of the particle beam energy, and regulating the contour of the particle beam. The path length from the radiation source to the isocenter is constant regardless of the rotation angle of the rotating gantry.

The patient A receives treatment while sitting on a treatment chair (not shown). Therefore, the particle beam is irradiated from a direction having a solid angle of 20 ° with respect to the rotation axis (horizontal axis) 1 of the rotating gantry. By changing the direction of the treatment chair, the particle beam can be emitted from an arbitrary angle in the circumferential direction of the body axis.

In this radiotherapy apparatus, the rotating shaft 1 is horizontal as in the prior art, but since the irradiation shaft 2 intersects the rotating shaft 1 with a large inclination, the occupied volume of the rotating gantry is smaller than in the prior art. Is very small. Therefore, both the radiation shielding facility and the building become smaller. Further, although a little underfloor space 31 is required, the treatment chair is arranged on the floor, so that access to the patient is easy.

FIG. 4 shows a third embodiment. This radiation therapy apparatus is mounted on a vertically movable gantry (not shown) that can be moved up and down, and is variably attached to the vertically movable gantry.
An irradiation field forming device 3 for guiding a particle beam to a desired irradiation field along the irradiation axis 2 and a deflection magnet 42a for deflecting a particle beam emitted along a horizontal axis 41 from a non-illustrated source at an angle variable.
And a deflecting magnet 42b for deflecting the particle beam variably in the direction of the irradiation axis 2.

In this radiation therapy apparatus, the deflection angles of the deflection magnets 42a and 42b and the angle of the irradiation field forming device 3 are controlled in conjunction with each other in accordance with the position of the lifting gantry. The irradiation axis 2 is on a vertical plane with respect to the horizontal axis 41, for example,
It can be changed in the range of ± 20 °. The path length from the source to the isocenter is slightly different depending on the angle of the irradiation axis 2. The difference in the state of the particle beam due to the difference in the path length may be adjusted by a focusing magnet (not shown) arranged between the deflection magnets.

Patient A receives treatment while sitting on a treatment chair. The particle beam is irradiated from an arbitrary direction within a range of ± 20 ° up and down. By changing the direction of the treatment chair, the particle beam can be emitted from an arbitrary angle in the circumferential direction of the body axis.

In the case of this radiotherapy apparatus, the volume occupied is very small because there is no rotational movement, and the radiation shielding facility and the building are small. Moreover, although a little underfloor space 43 is required, the access to the patient is easy because the treatment chair is arranged on the floor.

The invention example shown in FIG. 4 is applicable to the case shown in FIG. That is, the deflection magnet 4b is moved linearly from the upper right to the lower left in the drawing.

[0034]

The present invention exhibits the following excellent effects.

(1) Since the irradiation field forming device is provided obliquely with respect to the rotation axis, the space required for the rotational movement is reduced, and a low-cost, small-volume radiotherapy device is realized.

(2) Since the rotating shaft is inclined with respect to the horizontal, the space required for the rotating motion is efficiently stored in the square building, and the occupied volume is further reduced.

(3) Since no underfloor space is required, the cost of the building is reduced, and the access to the patient is facilitated because the treatment bed is arranged on the floor.

[Brief description of the drawings]

FIG. 1 is a side view of a radiotherapy apparatus according to a first embodiment of the present invention.

FIG. 2 is a sectional view of the radiotherapy apparatus of FIG. 1 stored in a building.

FIG. 3 is a side view of a radiation therapy apparatus according to a second embodiment of the present invention.

FIG. 4 is a side view of a radiation therapy apparatus according to a third embodiment of the present invention.

FIG. 5 is a cross-sectional view of a conventional radiotherapy apparatus stored in a building.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Rotation axis 2 Irradiation axis 3 Irradiation field forming apparatus 4a, 4b, 4c Deflection magnet

 ──────────────────────────────────────────────────の Continued on the front page F-term (reference) 4C082 AC04 AC05 AE03 AG11 AG11 AG21 AG52 AJ02

Claims (3)

[Claims] A rotating gantry rotatable about a rotating axis, an irradiation field forming apparatus mounted on the rotating gantry, for guiding a particle beam to an irradiation field along an irradiation axis crossing the rotating axis;
In a radiation therapy apparatus comprising a plurality of deflection magnets for deflecting a particle beam supplied along a rotation axis in a direction of an irradiation axis and guiding the beam to an irradiation field forming apparatus, the irradiation axis is inclined with respect to the rotation axis. A radiation therapy device characterized by being crossed. 2. The radiotherapy apparatus according to claim 1, wherein the rotation axis is inclined with respect to the horizontal. 3. The radiotherapy apparatus according to claim 2, wherein the rotation axis is inclined by 45 ° with respect to the horizontal, and the irradiation axis is inclined by 45 ° with respect to the rotation axis.