JPS6182763A - Punching apparatus in radiation treatment apparatus - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a punching device that prevents M rays from hitting healthy tissue inside or near a lesion when treating a lesion using a radiation therapy device.

[Technical background of the invention and its problems 1 The radiation therapy 8i device irradiates a lesion with radiation to destroy and treat the lesion, such as cancer cells. Therefore, as shown in Fig. 6, the radiation source is generally rotated to irradiate the lesion so that the lesion is located at the center of rotation.

That is, a U-shaped rotary pedestal 3 is supported on a base 1 fixed to the floor so as to be rotatable about 3600 degrees or more in the six directions of arrows with the shaft 2 as the center of rotation. A radiation source is housed in one side of the rotating frame 3, and a movable diaphragm @5 is attached to the radiation opening of the rotating frame 3 to appropriately restrict the radiation from the radiation source according to the shape of the lesion of the subject 4. The above-mentioned punching device 6 is fixed to the radiation opening of the movable aperture device 5. An opposing plate 7 is fixed to the other side of the rotating frame 3 for shielding radiation from the radiation source side and maintaining balance with the radiation source side. still,
The subject 4 is placed on a bed 8 fixed to the floor and movable up and down, and positioned on the central axis of rotation as shown by the arrow.

By the way, in the conventional punching device @6, as shown in FIG. 7, a punching body 10 is mounted between two opposing discs 9 and supported by a shaft.

The function of this conventional device (shielding for radiation punching of the eyeball in treating lesions near the center of the head) will be explained below with reference to FIG. The radiation emitted from the radiation source is set to be irradiated in a limited manner to the lesion 12 within the head 11 by the movable aperture 5a. When the center of the lesion 12 is aligned with the center of rotation of the pedestal and the pedestal is rotated, the radiation is concentrated on the lesion. In this rotational irradiation, radiation (eyeball 1, which is easy to receive radiation)
3. Exposure to radiation cannot be avoided. Therefore, a radiation punching device 6 is used to protect the eyeball 13. Set the two target objects (radiation shields) 10 corresponding to the eyeball 13 as E' for the actual eyeball interval and F' for the rotation center (center of the lesion) D and the actual distance F between the eyeballs. do. The disk 9 to which the punching body 10 is attached rotates in the direction of the arrow B centering on C in synchronization with the rotation angle of the mount at a ratio of 1:1.
and the eyeball 13 to shield radiation. This relationship does not change whether the frame is rotated by 3606 or in the opposite direction.

However, in this type of punching device, as the distance F between the center of the lesion and the eyeball increases, the diameter of the disc 9 needs to be further increased. The distance I between the radiation port 14, which is the mounting position of the punching device @6, and the center of rotation of the pedestal should be as wide as possible from the viewpoint of treatment operability and interference with the patient, bed, etc., but due to the structure of the irradiation device. It is limited in terms of radiation shielding and radiation shielding.

Therefore, as the punching body mounting disk 9 becomes larger, the height of the punching device 6 increases, and the distance between the center of rotation of the frame and the punching device 1i1 increases.
1f K becomes extremely narrow and interference with the patient, bed, etc. is likely to occur.

In addition, the workability for positioning the patient deteriorates, and it has such a major drawback that it cannot be used in a treatment device with a narrow space between the center of rotation of the gantry and the radiation source S.

[Objective of the Invention 1] The present invention has been made in view of the above-mentioned circumstances, and provides a punching device for a radiotherapy device that can be made smaller by linearly moving the punching body corresponding to the rotation angle of the rotary mount. The purpose is to provide equipment.

[Summary of the Invention] In order to achieve the above-mentioned object, in the present invention, a shielding body that can move linearly in a direction substantially orthogonal to the radiation cone to be irradiated is arranged between the radiation source and the subject. It is characterized by the fact that

[Embodiments of the Invention] Hereinafter, the configuration of an embodiment of the present invention will be described with reference to FIG.

A punching device 15, which is a feature of the present invention, is fixed to the irradiation port of a movable aperture ε attached to the side of the rotating frame that accommodates the radiation source. As shown in FIG. 3(b'), this punching device 15 has two lead screws 16a and 16b rotatably supported between two opposing walls of a cover 15'a that covers the device. A punched body 17aJ17 formed on the screw threads of -16a and 16b from an X-ray opaque material, such as lead or tungsten, to match the size of the eye.
1) is fitted. A guide rail 18 is arranged between the two lead screws, and the punched bodies 17a, 1
7b are engaged so as to be movable in the direction of the arrow X, respectively. Further, a drive mechanism 198, 19b is arranged at each end of the two lead screws 16a, 16b, and the drive mechanism 198, 19b is arranged to lead only the amount of drive, that is, the amount of rotation, according to the angle value from the angle detection section of the rotating frame (not shown). It rotates the screw. With such a configuration, the arrows X of the punching bodies 17a and 17b are
Directional movement is possible.

Next, the operation of the above configuration will be explained with reference to FIG. Like FIG. 7, this FIG. 2 is also a conceptual diagram of the case where the punching apparatus of the present invention is used to block radiation to the eyeball during rotational radiation therapy for a lesion near the center of the head. . Also, the radiation emitted from the radiation source S is transmitted through the movable aperture 5.
The beam is irradiated to a lesion 12 within the head 11, which is limited by a. Close eyeball 1 in rotating irradiation or multi-field irradiation, etc.
In order to reduce the radiation exposure to the radiation source S and the eyeball 13, shielding bodies 17a and 17b are provided between the radiation source S and the eyeball 13, and are moved perpendicularly to the central axis of the radiation cone. In the case of eyeball punching, the punching body 17a is used in synchronization with the rotation angle of the rotating mount during rotating irradiation or multi-field irradiation.
, 17b each move in the direction of arrow X. Punching body 1
The amount of movement of 7a and 17b controls the relationship between the distance F from the center of the lesion 12 (rotation center of the pedestal) D to the eyeball 13, the interocular distance E, and the rotation angle of the rotating pedestal. In the case of irradiation from above, the eyeball device 15 is placed above the eyeball 13 as shown in the figure so that it is attached to the radiation port 14, so that each eyeball 13 is shielded by the eyeball body 17a, 17b. . As the rotary stand rotates in the six directions of the arrow, the punched bodies 17a, 1
7b are moved in opposite directions. Furthermore, there are 9 rotating stands.
Even when the direction is 0', the movement continues in the same way. Therefore, the punching bodies 17a and 17b are always connected to the radiation source S and the eyeball 1.
3, and can punch out (shield) Group 11 FI wires.

It should be noted that the present invention is not limited to the above embodiments, but can be implemented with various modifications. For example, as shown in FIG. 3, when treating the larynx, neck, thyroid gland, hypopharynx, etc. in addition to the eyes, it is necessary to shield the neck 20. In this case, lesion 2
1 is rotated or multi-field irradiated, the cervical fIN 20 is prevented from being exposed to radiation using a punched body 22. Punching body 2 in this case
2 has a curved neck 20, so the punched body 22 is formed into a bent cylindrical shape as shown in FIGS. 3(c) and 3(d), and is passed through the shaft 23. In the state shown in FIG. 3(a), the punched body is set as shown in FIG. 3(C), and in the case of gantry rotation irradiation, the arrow is When rotated in the P direction, when the gantry rotation angle reaches 90°, the irradiation direction changes as shown in FIG. 3(b), and the punched body 22 changes as shown in FIG. 3(d). At this time, the hitting range of ° is shown in Figure 3 (a > (b)
This is indicated by 24. Such a punching device is constructed as shown in FIG. That is, the opposing cover 153 of the punching device
Two lead screws 25a are rotatably arranged in the
, 25b are respectively engaged with two engaging members 26a, 26b, so as to move in the direction of arrow X according to the rotation of each lead screw 25a, 25b, and between these engaging members 26a, 26b, A punched body 22 supported by a shaft 23 is rotatably supported in the direction of arrow P. Each lead screw 25a, 25b is rotated by the drive structure 27 in accordance with the rotation angle of the pedestal, and the punched body 2
2 in the X direction is controlled.

Incidentally, the rotation of the punched body 22 in the direction of the arrow P is generally carried out by fixing a support rod perpendicular to the shaft 23 on the extension of the shaft 23, and attaching a weight to the tip of the support rod, as in the conventional apparatus, for example. However, the engagement member 26a or 2
Drive to either side of 6b! A method may also be used in which the IJI source (such as a motor) is fixed and the drive of the shaft 23 is controlled according to the rotation angle of the rotating frame.

The operation of this modification will be explained based on FIG. 5.

Radiation from the radiation source S is limited by the movable aperture 5a and irradiated to the lesion 21. In order to protect the neck 20 of the neck 27, a neck punch 22 is set between the radiation source S and the lesion 21. The rotating mount rotates around the lesion center (rotation center) D, but since the position of the neck 1) if 20 is shifted by F from the center of the lesion, the mount rotation angle is increased by +111 and moved in the direction of the arrow X. let Furthermore, as described above, in order to conform to the curvature of the neck 20, the punched body 22 is rotated in synchronization with the rotation of the gantry about the shaft 23 shown in FIG. These operations are automatically controlled via calculation functions.

In this way, according to this embodiment, the height of the punching device and the thickness of the radiation in the radial direction can be made much lower than in the conventional rotating disk method, so there is no possibility of interference with the patient or the bed. It has an excellent effect of eliminating defects.

[Effects of the Invention] According to the present invention described above, since the punching body is configured to move linearly in a direction substantially orthogonal to the radiation cone,
This allows the punching device to be made smaller.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an embodiment of a punching device according to the present invention;
Fig. 2 is a conceptual diagram showing the operation of the device shown in Fig. 1, Fig. 3 is an explanatory diagram for another embodiment, Fig. 4 is a diagram showing the batting method device for J3 in Fig. 3, Fig. 5 3 is a conceptual diagram showing the operation of another embodiment of the apparatus shown in FIG. 3, FIG. 6 is a diagram illustrating a general radiation therapy apparatus, and FIG. 7 is a conceptual diagram explaining the operation of a conventional batting device. . S...Radiation source, 4...Subjects 17a, 17b, 22-...Representative for stricken body Patent attorney Noriyuki Chika (and 1 other person) Figure 1 (a) Figure 4 3rd prisoner p Figure 5 Figure 6

Claims (1)

[Claims] A punching device for a radiation therapy apparatus, in which a shielding body capable of moving linearly in a direction substantially perpendicular to a radiation cone to be irradiated is arranged between a radiation source and a subject.