JP3079346B2 - 3D particle beam irradiation equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for irradiating an object to be irradiated with a particle beam such as a neutron beam or a proton beam, and more particularly to a medical three-dimensional neutron irradiation apparatus used for cancer treatment and the like.

[0002]

2. Description of the Related Art At present, X-ray electron beams and neutron beams are mainly used for treating cancer with radiation.

[0003] As this type of radiotherapy apparatus, Japanese Patent Publication No. 51-15357, Japanese Patent Application Laid-Open No. 53-14297, and Japanese Patent Application Laid-Open No. 53-72392 have been disclosed. ).

[0004] Prior art 1 discloses an irradiation apparatus configured to move a treatment table while keeping a horizontal posture without moving a neutron source, and to move a collimator to the side.

[0005] Prior art 2 discloses a neutron therapy facility using a cyclotron. Some examples of these neutron therapy facilities are shown in FIGS.

In the example of FIG. 5, a pivot 128 is provided between opposed surfaces of a concrete wall 132, a cyclotron 130 is rotatably provided on the pivot, and a pedestal 140 is provided on a platform. Is a two-dimensional irradiation device that changes the irradiation angle around the axis passing through the affected part parallel to the patient's central axis in a plane that intersects the central axis. , See FIG. 7 of Prior Art 2 and its description).

[0007] In the example of FIG.
0 is rotated around a target axis 101 and a treatment table (not shown) is vertically moved therewith, and a two-dimensional irradiation apparatus is shown in the same manner as in FIG. (See FIG. 8 of the technology 2 and its description).

In the example shown in FIG. 7, a U-shaped frame 1 which rotates around a hollow shaft 107 around a patient treatment table is provided.
05 is rotated to rotate the cyclotron 100 held by the U-shaped frame 105 around an axis 111. The gear 108 meshes with a gear provided concentrically with a hollow shaft 107 supported by a wall 106. A two-dimensional irradiator configured to transmit a rotational force to a cyclotron by a driven shaft 109 and a shaft 110 at one end of a U-shaped frame 105 is shown (see FIG. 9 of prior art 2 in detail). And its description).

FIG. 8 shows three pole pieces 12.
1, a target mounting zone 122 is provided, and a magnetic fragment 124 having a neutron beam outlet 123 is provided between the magnetic pole pieces 121, so that three targets 125 are prepared and can be taken out from three sides. 5 or 7 with the center axis of the cyclotron parallel to the center axis of the patient (or the apparatus of FIG. 10 of prior art 2)
To form a two-dimensional irradiation apparatus (for details, see FIG. 12 of Prior Art 2). Thus, Prior Art 2 shows a two-dimensional rotating irradiation device.

In the prior art 3, the neutron irradiation treatment machine holds the cyclotron accelerator and the patient table for stationaryly supporting the patient in the patient treatment area, while maintaining the balance of the weight with the cyclotron, And a gantry for holding the patient table 17. A target and a neutron collimator are provided in the cyclotron. This target is the first
And a second material, wherein the first material produces a large amount of high energy neutrons when bombarded with high energy protons, and the second material produces a relatively small amount of bombardment when bombarded with low energy protons. Produces neutrons. The neutron collimator matches the lobe of the neutron flux emanating from the target,
Adjustable to change the cross-sectional area and / or direction of the neutron beam applied to the patient treatment area. In this neutron irradiation treatment machine, a cyclotron is rotated by a gantry around one axis passing through a patient.

[0011]

As shown in FIG. 9, the dose of X-rays and neutron rays decreases from the body surface to a deeper part. Therefore, in order to irradiate the required dose to the cancer site, it is inevitable that the irradiation dose near the surface of the body will be excessive, and normal tissue may be damaged. This problem is expected to be suppressed to some extent by the two-dimensional rotating irradiation apparatus of the prior art 2.

However, in the two-dimensional rotating irradiation apparatus described above, the direction of radiation is deviated. For example, in the apparatus shown in FIG. 5, irradiation is performed in a plane including an axis parallel to the central axis of the patient passing through the affected part. Since the angle cannot be changed, the cancer site cannot be irradiated with radiation from all directions, and there is still a problem in irradiating a large amount of radiation only to the cancer site.

Accordingly, one technical object of the present invention is to provide a three-dimensional particle beam irradiation apparatus capable of irradiating a neutron beam from all directions.

Another technical object of the present invention is to provide a medical three-dimensional neutron beam capable of reducing damage to normal tissues and improving the degree of concentration of a dose on a treatment affected part during cancer treatment with neutrons. An irradiation device is provided.

[0015]

According to the present invention, there is provided a particle beam emitting device for emitting a particle beam toward an irradiation target on one axis, and rotating means for revolving the particle beam emitting device around the one axis. A particle beam irradiation apparatus comprising: an irradiation angle changing unit for changing an angle between the particle beam and the one axis; and the irradiation angle changing unit includes the particle beam emitting device.
Position and the irradiation target are relatively moved in a direction along the one axis.
Relative moving means, and relative movement by the relative moving means.
The exit angle that changes the exit direction of the particle beam in conjunction with
A three-dimensional particle beam irradiation apparatus characterized in that the three-dimensional particle beam irradiation apparatus includes a diverting means so that a particle beam from the particle beam emission apparatus is incident on the irradiation object from various different directions.

[0016]

According to the present invention, in the three-dimensional particle beam irradiation apparatus, the particle beam emitting means includes a cyclotron, and the emission angle varying means includes a plurality of particles having different angles on the final trajectory of the base particle of the cyclotron. A plurality of particles corresponding to the plurality of locations for extracting a target disposed at one location selected from the locations and daughter particles generated by collision of the base particles with the target to the outside of the cyclotron; A three-dimensional particle beam irradiation apparatus characterized by having a line drawing hole is obtained.

According to the present invention, in the three-dimensional particle beam irradiation apparatus, the emission angle changing means includes a particle beam guide means coupled to the cyclotron to guide the particle beam, and the particle beam guide means includes: A shield portion for opening only one of the plurality of particle beam extraction holes and closing the other particle beam extraction holes, wherein the shield portion is movable along the final orbit of the base particle of the cyclotron. Thus, a three-dimensional particle beam irradiation apparatus is obtained.

According to the present invention, in any one of the three-dimensional particle beam irradiation apparatuses described above, the relative moving means is interlocked with the emission angle changing means on a particle beam irradiation apparatus or a treatment table on which the irradiation target is placed. A medical three-dimensional neutron irradiation device characterized in that the particle beam is a neutron beam.

[0020]

According to the present invention, by changing the angle between the revolving motion about one axis of the particle beam emitting device and the one axis with the particle beam as described above, various types of particle beams can be applied to the irradiation object. It becomes possible to make it enter from a direction. That is,
Particle beam irradiation can be performed in a direction along one axis of the particle beam, and the irradiation target can be three-dimensionally irradiated to the irradiation target in combination with a rotating means for rotating the particle beam source around one axis.

[0021]

Embodiments of the present invention will be described below. In the embodiment of the present invention, a medical three-dimensional neutron irradiation device used for cancer treatment will be exemplified as the three-dimensional particle beam irradiation device.

FIGS. 1A and 1B are a plan view and a front sectional view showing a medical three-dimensional neutron irradiation apparatus according to an embodiment of the present invention. Referring to FIGS. 1A and 1B, a medical three-dimensional neutron irradiation apparatus 10 generates a proton or deuteron beam as a base particle and generates a particle beam extraction hole 1a, 1b.
b, 1c, and a target 2, which is provided on the final extraction trajectory of the cyclotron 1 and can be attached to and detached from the cyclotron 1 as a particle beam source for generating neutrons as daughter particles from the proton beam. 3 and 4, and a guide hole 5a for guiding neutrons from the cyclotron 1 to act as a particle beam guiding means and also serve as a collimator to protect the patient from radiation,
The shield unit 5 which is relatively movable in conjunction with the treatment table 7 and the cyclotron 1 are supported. The rotating unit rotates 180 ° around the z-axis while always keeping the direction of the beam emitted from the cyclotron 1 in the radial direction. A mechanism 6 and a treatment table 7 and / or a treatment table which can be relatively moved in the z-axis direction with a patient placed thereon as a relative movement means are fixed (or movable), and the cyclotron 1 (particle beam emission device) is rotated by a rotation mechanism 6 And a device for moving in one axis direction.

Here, the particle beam emitting device according to the present invention includes the cyclotron 1. The irradiation angle changing means includes a cyclotron 1 which is a particle beam emission device,
In conjunction with the relative movement between the treatment table 7 and the cyclotron 1 for moving the affected part of the patient to be irradiated in the z-axis direction,
Targets 2, 3, and 4 are provided as output angle changing means for changing the output direction of the particle beam.

The rotating mechanism 6 has a support portion 6a for supporting the cyclone and a counter balance weight 6a at an opposing position to balance the cyclotron 1 with the z-axis.
These are provided so as to be rotatable around the z-axis by the rotating unit 6c.

The shield section 5 is rotated concentrically with the cyclotron 1 by a shield section moving mechanism 12 having a telescopic rod provided on a fixed section, so that the positions of the targets 2, 3, and 4 can be set. Based on this, the particle beam extraction holes 1a, 1b, 1c are set at predetermined positions so as to coincide with the guide holes 5a.

In this medical three-dimensional neutron irradiation apparatus, the cyclotron 1 can be rotated around the patient by the rotation mechanism 6 to irradiate neutrons two-dimensionally. Furthermore,
This device attaches three sets of targets 2, 3, and 4 that can be put in and taken out on the final withdrawal orbit of the cyclotron 1, and performs three-dimensional irradiation by relatively moving the patient, the cyclotron 1, and the treatment table 7 in the z-axis direction. It can be carried out. In the present invention, the neutron source refers to targets 2, 3, and 4 provided in the cyclotron 1.

FIGS. 2 (a), 2 (b) and 2 (c) show FIG.
It is a figure which shows the target operation | movement of the medical three-dimensional neutron irradiation apparatus of (a) and (b). In FIG. 2A, the target 3 is set at a position where the angle θ of the normal of the target surface to the direction of the treatment table 7 is 90 ° on the final extraction orbit of the cyclotron 1. The shield portion 5 is moved and set by the shield portion moving mechanism 12 so that the guide hole portion 5a provided in the shield portion 5 overlaps the particle beam extraction hole 1a and shields the particle beam extraction holes 1b and 1c. I have. The neutron beam generated from the target passes through the particle beam extraction hole 1a and the guide hole 5a in the vertical direction to the patient 8.
Is irradiated to the affected part 21 of the patient.

In FIG. 2B, the target 3 is moved by the shield moving mechanism 12 to a position where the angle θ of the normal of the surface of the target 3 to the treatment table 7 is 60 degrees on the final drawing orbit of the cyclotron 1. Is set. In addition, the guide hole 5a provided in the shield 5 is
It is set so as to overlap with the particle beam extraction hole 1b.
The treatment table 7 is moved in the horizontal direction (leftward in the figure) by a moving means (not shown) in accordance with the movement of the target 3 and the shield section 5, and is set at a predetermined position. The neutron beam generated from the target 3 is radiated through the particle beam extraction hole 1b and the guide hole 5a in a direction at an angle of 60 ° with respect to the horizontal direction, and the affected area 21 of the patient 8 placed at a predetermined position. Incident on.

In FIG. 2 (c), the target 4 is moved and set by the shield moving mechanism 12 to a position where the angle θ of the normal of the target surface to the treatment table 7 is 120 on the final withdrawal trajectory of the cyclotron 1. ing. The guide hole 5a provided in the shield 5 is set so as to overlap with the particle beam extraction hole 1c. Then, in response to the movement of the target and the shield unit 5, the treatment table 7 is moved in the horizontal direction by the moving means (not shown) (right direction in the figure), and set to a predetermined position. The neutron beam generated from the target 3 is radiated through the particle beam extraction hole 1b and the guide hole 5a in a direction at an angle of 60 ° with respect to the horizontal direction, and the affected area 21 of the patient 8 placed at a predetermined position. Incident on.

As described above, in addition to the neutron generator rotating 180 ° (two-dimensionally) around the patient, three-dimensional irradiation including the z-axis direction can be performed by setting the target position at several points indicated by 2, 3, and 4. It is possible by installing and changing the direction of the beam.

In this three-dimensional irradiation, for cancers that have developed not in the body surface but in the patient's body, a large number of irradiations are performed in different directions to minimize the neutron irradiation of normal tissue from the surface to the deep part. Do.

FIG. 3 is a schematic diagram for explaining the advantages of performing two-dimensional irradiation. In FIG. 3, arrows 22, 2
As shown by 3, 24, 25, 26, and 27, when the irradiation of the diseased part is considered evenly from six directions, if the diseased part (center) is set to 21, the part 31 has a dose of 1/6 and the part 3
2 is 2/6, part 33 is 3/6, part 34 is 4/6, part 35 is 5/6, part 36 is 6/6, and the surface 31
Becomes 1/6 of the dose of the affected area 21, the overlap becomes large in two-dimensional irradiation, and irradiation from six directions is the limit,
In the apparatus of the present invention, by changing the irradiation angle three-dimensionally in this way, compared with the case of two-dimensionally neutron irradiation, the irradiation dose to the normal tissue part is dispersed, This is extremely advantageous in that damage to normal tissue can be reduced because irradiation can be performed in a concentrated manner.
In particular, in the apparatus shown in FIGS. 1 and 2, the configuration in which the irradiation angle is changed in three directions is illustrated. However, as shown in FIG. 3, a target and a particle beam extraction hole are further provided, and irradiation is performed in six directions or more. It is also possible to configure so that the corner can be turned.

FIG. 4 is a diagram showing a dose distribution calculated in a more realistic manner at the position from the affected part on the body surface when irradiation in 15 directions is performed. In FIG. 4, it is created assuming a cancer 10 cm deep from the body surface. As shown in this figure, the dose distribution becomes maximum at the affected part, and the body surface part has a dose distribution of one-tenth of the dose distribution, and it can be seen that the burden on the patient is considerably reduced.

[0034]

As described above, according to the present invention,
A small and inexpensive three-dimensional particle beam irradiation device can be provided.

Further, according to the present invention, there is provided a medical three-dimensional neutron irradiator capable of reducing damage to normal tissues and improving the degree of concentration of a dose on an affected part during cancer treatment with neutron rays. be able to.

[Brief description of the drawings]

FIG. 1A is a plan view showing a medical three-dimensional neutron irradiation apparatus according to an embodiment of the present invention. (B) is a front sectional view of the medical three-dimensional neutron irradiation apparatus of (a).

FIGS. 2A, 2B, and 2C are diagrams for explaining a target operation of the medical three-dimensional neutron irradiation apparatus of FIGS. 1A and 1B;

FIG. 3 is a diagram schematically showing a case where three-dimensional irradiation is performed in a large number of times.

FIG. 4 is a diagram showing a dose distribution at a position from an affected part on a body surface.

FIG. 5 is a front view showing an example of a part of a conventional neutron irradiation device.

FIG. 6 is a front view showing another example of a part of the conventional neutron irradiation apparatus.

FIG. 7 is a front view showing still another example of a part of the conventional neutron irradiation apparatus.

FIG. 8 is a front view showing another example of a part of the conventional neutron irradiation apparatus.

FIG. 9 is a diagram for explaining a difference between a particle beam and another radiation.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cyclotron 1a, 1b, 1c Particle beam extraction hole 2, 3, 4 Target 5 Shield part 5a Guide hole part 6 Rotating mechanism 7 Treatment table 8 Patient 10 Medical three-dimensional neutron irradiation device 12 Shield part moving mechanism 21 Affected part 22, 23, 24, 25, 26, 27 Arrow

────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Fuminobu Soga 4-9-1, Anagawa, Inage-ku, Chiba-shi, Chiba Prefecture Inside the National Institute of Radiological Sciences (72) Inventor Norio Tanono 4-9-1 Anagawa, Inage-ku, Chiba-shi, Chiba No. 1 Inside the National Institute of Radiological Sciences (56) References JP-A-7-227435 (JP, A) JP-A-7-163669 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) ) A61N 5/01

Claims (5)

(57) [Claims] 1. A particle beam irradiation device comprising: a particle beam emission device that emits a particle beam toward an irradiation target on one axis; and a rotation unit that revolves the particle beam emission device around the one axis. An irradiation angle changing means for changing an angle formed between the particle beam and the one axis; and the irradiation angle changing means.
Is the axis of the particle beam emitting device and the irradiation object
Relative moving means for relatively moving in the direction along the
Direction of the emission of the particle beam in conjunction with the relative movement by the moving means.
A three-dimensional particle beam irradiation apparatus , comprising: an emission angle changing means for changing the direction of the beam ; and causing the particle beam from the particle beam emission apparatus to enter the irradiation target from various different directions. 2. A three-dimensional particle beam irradiation apparatus according to claim 1 , wherein said particle beam emitting means includes a cyclotron,
The output angle diverting means is formed by colliding the target disposed at one position selected from a plurality of positions at different angles on the final trajectory of the base particle of the cyclotron with the base particle. A three-dimensional particle beam irradiation apparatus, comprising: a plurality of particle beam extraction holes corresponding to the plurality of locations for extracting the extracted daughter particles to the outside of the cyclotron. 3. The three-dimensional particle beam irradiation apparatus according to claim 2 , wherein the exit angle changing means includes a particle beam guiding means coupled to the cyclotron to guide the particle beam, and the particle beam guiding means. Includes a shield portion that opens only one of the plurality of particle beam extraction holes and closes the remaining particle beam extraction holes, wherein the shield portion is movable along the final trajectory of the base particle of the cyclotron. A three-dimensional particle beam irradiation apparatus, characterized in that it is a three-dimensional particle beam irradiation apparatus. 4. The three-dimensional particle beam irradiation apparatus according to claim 1 , wherein said relative movement means carries said irradiation object and interlocks with said emission angle turning means to produce said particle beam. 3. A medical three-dimensional neutron irradiation apparatus, comprising: a treatment table for moving to an irradiation position of (1), wherein the particle beam is a neutron beam. 5. The three-dimensional particle beam irradiation apparatus according to claim 1 , wherein the relative moving unit includes:
A medical three-dimensional neutron irradiation apparatus, comprising: a device for moving the particle beam emitting device in a uniaxial direction in conjunction with the emission angle changing means, wherein the particle beam is a neutron beam.