JPH06130200A - Radiation irradiating device - Google Patents

Abstract

PURPOSE:To enable irradiating radiation at one point with a high position accuracy by using a means for electrically controlling an electron beam for controlling the radiation irradiation direction distributing the radiation generation points three dimensionally and irradiating from an arbitrary directions at a microspot. CONSTITUTION:An accelerated 1 electron beam 2 is converged with 4 electropole lens 3 and irradiate a target 5 by receiving reversed bias by a bias meters 4-1 and 4-2. The target 5 radiates radiation 6 and the radiation 6 is colimated 7 so as to irradiate a microspot 8 in the head of a patient. Here the beam 2 is scanned in turn from the targets 5-1 to 5-9 corresponding to the colimeter 7-1 to 7-9. This is done by changing the bias intensity of bias meters 4-1 to 4-2. At this moment, the lens 3 is synchronized to strengthen the lens intensity and the beam 2 is converged thin on the target 5. The bias meters 4-1 and 4-2 and the target 5 rotate altogether therefore, the radiation can be irradiated to a microspot 8 from three dimensionally different angle.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radiation irradiating device, and more particularly to a radiation irradiating device having a radiation generating mechanism by an electron beam, and is particularly suitable for treatment of irradiating a single point in a patient's body from any direction. Radiation irradiation device.

[0002]

2. Description of the Related Art An apparatus for generating radiation by using an electron beam accelerated to high energy by an accelerator and using this radiation for treatment generally has a structure as shown in FIG. That is, the electron beam 2 is applied to the radiation generation target 5 in the irradiation head 10 to generate the radiation 6. This radiation source is generally the irradiation head 10.
It is fixed inside. Therefore, the irradiation direction and position are changed by rotating the gantry 11 or moving the treatment table 9. However, there is a problem in that the degree of freedom in the irradiation direction is poor, and the Japanese Patent Laid-Open Publication No. 55-83.
As described in 900, a gantry capable of swinging and rotating the irradiation head 5 with respect to the gantry 11 has also been devised.

[0003]

However, in the conventional device, in order to irradiate one point in the patient's body from any direction, it is necessary to perform complicated operations of the irradiation head and the treatment table. There is a problem that it is difficult to maintain the high positional accuracy required at the treatment site. Also, it is known that a large number of radiation sources using cobalt are fixedly arranged on a spherical surface in order to irradiate a single point in the patient's body with radiation, but this is not desirable from a medical point of view, It is desirable to irradiate a point in the body with an electron beam from an arbitrary direction. An object of the present invention is to provide a radiation irradiating device using an electron beam that can irradiate a single point with high positional accuracy from a desired direction.

[0004]

In order to achieve the above object, the radiation irradiation apparatus of the present invention electrically deflects and controls an electron beam accelerated by an accelerator to irradiate a plurality of radiation generation positions. A configuration is provided in which a deflector and a collimator that narrows the radiation beam so that the radiation generated at the plurality of radiation generation positions irradiate a minute point are provided. When an electron beam is used as the radiation, the deflector is controlled so that the electron beam converges on the minute point, except for the collimator. In a preferred embodiment of the above configuration, a plurality of radiation generating positions are arranged in a two-dimensional plane in a curved line such as an arc, and a target having a heavy metal such as gold that emits radiation is arranged on the bottom, and the deflector and The gantry including the target is configured to rotate with the line including the minute point as the rotation axis.

[0005]

According to the present invention, by controlling the irradiation direction of the radiation by using a means for electrically controlling the electron beam, the radiation generation points are three-dimensionally distributed, and the minute points are irradiated from any arbitrary direction. I did it. That is, the radiation generation point is set to be generated at a plurality of points instead of one point as in the conventional case. Furthermore, the radiation direction generated here is controlled by a collimator so that a desired point in the patient's body can be irradiated. Therefore, if the electron beam is electrically controlled and deflected by the deflector to irradiate the plurality of radiation generation positions, it is possible to irradiate the minute point with the radiation from any direction with high position accuracy.

[0006]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a cross-sectional view of an embodiment of the radiation irradiation apparatus according to the present invention, and (a) and (b) respectively show orthogonal cross sections. The electron beam 2 accelerated by the accelerator 1 is 4
It is narrowed down by the polar lens 3. Focused electron beam 2
Irradiates the arc-shaped target 5 by being deflected in opposite directions by the deflector 4-1 and the deflector 4-2. When the target 5 is irradiated with the electron beam 2, the target 6 emits the radiation 6, which is collimated by the collimator 7 and irradiates the minute point 8 in the head of the patient. Here, the electron beam 2 is transmitted from the collimator 7-1 to the collimator 7
Targets 5-1 to 5 corresponding to -9
Sequential scanning is performed up to -9. This is the deflectors 4-1 and 4-2.
This is done by changing the deflection intensity of. At this time, 4
The lens strength is also changed in synchronization with the polar lens 3 so that the electron beam 2 is always narrowed down on the target 5. By this scanning, the radiation 6 from the collimator 7 is configured to be focused on the minute points 8 and can be irradiated.

Further, the deflectors 4-1 and 4-2 and the target 5 are integrally rotatable (the integrated one is called a gantry) and mechanically rotatable about the C axis. Therefore, this rotation allows the minute point 8 to be irradiated with the radiation 6 from three-dimensionally different angles. In this embodiment, the collimator 7 is fixed to the treatment table 9 in order to control the irradiation position with high accuracy even when the gantry rotates. Therefore, the collimator 7 has a hemispherical shape. The collimator 7 has a shield function of preventing the radiation 6 from hitting other than the minute point 8. The treatment table 9 is movable up and down, left and right, and in the depth direction, and is adjusted so that the treatment site is located exactly at the center 8 of the collimator 7. The above is the basic configuration and operation of the gantry in this embodiment.

Next, a concrete example will be shown. A microtron was used as the accelerator 1, and the electron beam 2 having an energy of 6 MeV was taken out. As the quadrupole lens 3, three magnetic field types are used, and control is performed so that the beam diameter is always about 5 mm on the target 5 even when the electron beam 2 scans on the target 5 or mechanical rotation of the gantry. . The deflectors 4-1 and 4-2 for deflecting the electron beam 2 were magnetic field type, and the target 5 was gold. The collimator 7 for collimating the radiation 6 generated by the target 5 has a diameter of 10 mm on the side of the target 5 and has a semicircular shape made of lead having a large number of conical holes toward the center 8. Twenty-four pieces are arranged on the circumference. This implementation device was designed for the purpose of treating brain diseases such as dysfunction due to nerves in the brain, tumors in the brain, and vascular malformations.

FIG. 2 is a block diagram showing another embodiment of the radiation irradiation apparatus according to the present invention. This embodiment is suitable for radiotherapy of the whole body, and the basic construction and operation principle is the same as that of the embodiment of FIG. 1, but in this embodiment, the radiation 6 is emitted from the electron beam 2 to the target 5. The radiation 6 emitted in the incident direction is used for treatment through a collimator 7. Further, in FIG. 1, the electron beam 2 can be deflected in the opposite direction, but in the present embodiment, in order to reduce the size of the device, the electron beam 2 is deflected in only one direction, and the gantry 11 is rotatable by 360 °. Although the embodiments of the present invention have been described above, it goes without saying that the present invention is not limited to the above embodiments.
For example, the inner diameter of the collimator is cylindrical or inverted conical,
A collimator having a size suitable for the size of the treatment site and the application may be replaced and used. Further, the number of collimators, the beam size on the target, the energy of the electron beam, etc. are not limited to these. Further, the type and shape of the target are not limited to those in this embodiment and can be implemented. For example, the targets may be discontinuously arranged only at the positions corresponding to the holes of the collimator.

In the above embodiment, the radiation 6 generated by irradiating the target 5 with the electron beam 2 is used. However, for example, the target 5 and the collimator 5 may be removed and the electron beam 2 may be directly irradiated to the position of the treatment site as radiation. In this case, the position where the electron beam is narrowed down is controlled by the lens 3 so as to be the irradiation center position 8. When using this electron beam directly for treatment,
Since the penetrability of an electron beam is lower than that of radiation, it is preferable to change the energy of the electron beam according to the depth of the treatment site. Since the microtron used in this embodiment can easily change the energy of the electron beam,
It may be performed dynamically according to the depth of the treatment site depending on the irradiation direction of the beam. Of course, the accelerator is not limited to this, and can be implemented by using another accelerator such as a linac.

The point is that the accelerated electron beam is electrically deflection-controlled to irradiate a plurality of radiation generating positions, and a radiation collimator is provided so that the radiation generated here can irradiate a single point which is a minute point. As long as it is a radiation irradiation device and the gantry is mechanically rotatable, the essence of the present invention is not impaired. On the other hand, when the electron beam is directly used for the treatment, the electron beam may be electrically controlled to be deflected to irradiate one point on the treatment site. Of course, these can be realized by one gantry, and the embodiment of FIG. 1 has such a configuration.

[0012]

According to the present invention, since the radiation generation position can be controlled by electrically controlling the electron beam and the irradiation direction of the radiation can be limited by the collimator, a point in the patient's body can be positioned at a high position from any direction. This has the effect of providing a gantry that can irradiate radiation with precision.

[Brief description of drawings]

FIG. 1 is a sectional view of an embodiment of a radiation irradiation apparatus according to the present invention.

FIG. 2 is a sectional view of another embodiment of the radiation irradiation apparatus according to the present invention.

FIG. 3 is a schematic configuration diagram of a conventional radiation irradiation apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Accelerator, 2 ... Electron beam, 3 ... Quadrupole lens, 4, 4-1, 4-2 ... Deflector, 5, 5-1, 5-9 ... Target, 6 ... Radiation, 7, 7-1, 7-9 ... Collimator, 8 ... Minute point (center of collimator), 9 ... Treatment table, 10 ... Irradiation head, 11 ... Gantry.

Claims (9)

[Claims] 1. An accelerator for accelerating an electron beam, a deflector for electrically deflecting and controlling an electron beam from the accelerator to irradiate a plurality of radiation generation positions, and a plurality of radiation generation positions corresponding to the radiation generation positions. Radiation generating means arranged to generate radiation by irradiation of an electron beam, and a collimator for collimating the radiation so as to irradiate the radiation from the radiation generation positions to a specific minute point, Radiation irradiation device. 2. The radiation irradiating apparatus according to claim 1, wherein the radiation generating means is arranged two-dimensionally, and the deflector vertically irradiates an electron beam to a plurality of radiation generating positions of the radiation generating means. A radiation irradiating device, which is configured to electrically control deflection as described above. 3. The radiation irradiation apparatus according to claim 1, wherein the collimator is fixed, and the deflector and the radiation generating means are mechanically rotated. apparatus. 4. The radiation irradiating apparatus according to claim 3, wherein the collimator has a curved surface shape that prevents radiation from being applied to a portion other than the specific minute point. 5. The radiation irradiating apparatus according to claim 1 or 2, wherein a target made of gold is used as the radiation generating means. 6. An accelerator for accelerating an electron beam, and an electron beam from the accelerator is electrically deflected to control a plurality of electron beams.
A radiation irradiating device, comprising: a deflector for converging and scanning an electron beam so as to irradiate a specific minute point from a dimensional position. 7. The radiation irradiating apparatus according to claim 2 or 6, wherein a magnetic field type quadrupole lens is used as a means for narrowing the electron beam, and a magnetic field type deflector is used as the deflector. Radiation irradiation device. 8. The radiation irradiating apparatus according to claim 7, wherein the quadrupole lens is configured to focus the electron beam at a radiation generating position in association with deflection of the electron beam and mechanical rotation of the deflector. A characteristic radiation irradiation device. 9. The radiation irradiation apparatus according to claim 7, wherein the acceleration energy of the electron beam of the accelerator is changed in association with the mechanical rotation of the deflector.