JPH07116276A - Fixed position radiation treating device - Google Patents

Abstract

PURPOSE:To facilitate exchanging of a collimator with simple constitution by constituting the device in such a manner that the collimator is removable from an adjusting mechanism by movement in a central axis direction and regulating the movement in the central axis direction by detaining with a rod inserted into a groove formed orthogonally with the central axis direction on the outer periphery thereof. CONSTITUTION:The collimator 19 has the groove 35 formed along the peripheral direction in a part of the outer periphery thereof. The groove extending in a direction intersecting with the central axis is formed on a part of the outer periphery of a cylindrical member 70 housing the collimator 19. The groove is so formed as to expose a part of the groove 35 of the collimator 19. There is an attaching and detaching lever 40 inserted into the groove of the cylindrical member 70. The attaching and detaching lever 40 is also inserted simultaneously into the groove 35 of the collimator 19. As a result, the axial movement of the collimator 19 is regulated by the attaching and detaching lever 40 and the storage state into the cylindrical member 70 is maintained. The attaching and detaching lever 40 is supported on an X-direction table and is slidable in its axial direction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stereotactic radiotherapy apparatus, and more particularly to improvement of a collimator portion thereof.

[0002]

2. Description of the Related Art Among radiation treatment apparatuses, particularly called stereotactic radiation treatment apparatus, a narrow beam of radiation is formed, and this radiation beam is sequentially applied to a lesion of a subject from multiple directions. It was designed to destroy it.

In such a radiation treatment apparatus, since the amount of radiation applied to the surrounding normal part other than the lesion part can be extremely reduced, it is possible to prevent the normal part from being adversely affected by the radiation.

Therefore, for these reasons, it is a necessary condition that the radiation from the radiation source is reliably applied to the lesion with a predetermined beam diameter.

For this reason, the radiation from the radiation source is irradiated through the collimator, and the radiation that has passed through the radiation lead-out hole provided in the collimator forms a beam. Several kinds of collimators having radiation lead-out holes of different diameters are prepared in advance, and an appropriate collimator is exchanged according to the shape of the lesion and the like, and the collimators are sequentially used. .

[0006]

On the other hand, in the radiation therapy apparatus thus constructed, the so-called irradiation head cannot be adjusted at all afterwards, so that the manufacture of the apparatus itself is not possible. When a slight deviation occurs in the mounting of the collimator due to an error or the like at the time, there is a problem that the radiation beam is not reliably irradiated to the lesion.

Therefore, the Applicant has
Even after the collimator is attached, an invention relating to an adjusting mechanism capable of adjusting the swing of the collimator so that the radiation source is positioned on the extension line of the central axis of the radiation guiding hole is proposed (Japanese Patent Application No. 25799/1992). , Practical application 5-1
2410).

However, in any of these inventions, the mechanism for exchanging the collimator for other types is not sufficient in any of them, and it is necessary to make further improvements to achieve a simple structure and easy handling. It was.

The present invention has been made under such circumstances, and the object of the present invention is to provide a collimator having a simple structure despite having a collimator adjusting mechanism. An object of the present invention is to provide a stereotactic radiotherapy apparatus that can be easily replaced.

[0010]

In order to achieve such an object, the present invention basically irradiates radiation from a radiation source through a collimator, and the collimator is provided with the radiation. In the stereotactic radiotherapy apparatus provided with an adjusting mechanism for adjusting the oscillation so that the radiation source is positioned on the extension line of the central axis of the outlet hole, the collimator is moved from the adjusting mechanism by moving in the central axis direction. In addition to being configured to be removable, movement in the central axis direction is restricted by locking by a rod inserted into a groove formed on the outer periphery of the rod at right angles to the central axis, and the rod is It is supported by the adjusting mechanism and is movable in the axial direction so as to release the locking by inserting the collimator into the groove. It is intended to.

[0011]

According to the stereotactic radiotherapy apparatus having such a structure, the collimator in the normal state is locked by the rod inserted into the groove formed on the outer periphery of the collimator at right angles to the central axis. The movement in the direction of the central axis is restricted and the state of attachment to the adjustment mechanism is maintained.

By moving the rod in the axial direction, the insertion of the collimator into the groove can be released.

Therefore, the collimator which has been restricted by the rod can be moved in the direction of the central axis, and the collimator can be removed from the adjusting mechanism.

After that, by performing the reverse operation to the above, another collimator having a different diameter of the radiation guiding hole can be mounted in the adjusting mechanism.

Therefore, even though the collimator adjustment mechanism is provided, the collimator can be easily replaced with a simple structure.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 2 is an overall configuration diagram showing an embodiment of a stereotactic radiotherapy apparatus according to the present invention.

In the figure, this apparatus is supported by a support unit 1 and rotates around a patient 8 as shown by an arrow 20, an irradiation head 10 supported by this gantry 2, and an irradiation head 10 thereof. It comprises a collimator drive device 18 supported by and a treatment table 9 on which the patient 8 is laid. The gantry 2 and the irradiation head 10 are provided at a transport path 4 for transporting an electron beam 3 from an electron beam source (not shown), a deflection magnet 5 for deflecting the electron beam 3, and an exit portion of the electron beam 3. Between the vacuum window 6, the X-ray target 7 that emits X-rays when irradiated with the electron beam 3, the conical collimator 11 that narrows the emitted X-rays, the movable collimators 12 and 13, and the conical collimator 11 and the movable collimator 12. The filter 14 is provided. The filter 14 is a flattening filter that makes the X-ray dose distribution within the cone uniform.

In the state shown in FIG. 2, a vertical line 16 as the X-ray irradiation center and a horizontal axis 1 as the rotation center of the gantry 2.
The intersection with 7 becomes a so-called isocenter 15, and for example, in order to align a lesion such as cancer with this treatment table 9,
Position while moving up and down, left and right. The treatment table 9 is fixedly attached to a peripheral portion of a turntable 25 rotatably installed on a horizontal plane about a vertical axis 16 passing through the isocenter 15. In this way
With the rotation of the turntable 25, the treatment table 9 can rotate on the horizontal plane about the isocenter 15. The dolly 21 is provided for its rotation.

The movable collimators 12 and 13 each have two
It is composed of a single collimator block, and by arranging these four collimator blocks in a rectangular shape in the x and y directions,
Form an X-ray passage. The rectangular size is adjusted by changing the distance between the four collimator blocks. However, the movable collimators 12 and 13 only have a function of narrowing the radiation into rectangles at the ends, and cannot perform the operation of correcting the positional deviation with respect to one localized point. Therefore, a collimator 19 for localization is provided between the irradiation head 10 and the isocenter 15. In the conventional single-source type, the collimator 19 is fixed to the irradiation head 10, but in this embodiment, the collimator 19 is housed in the housing 24 fixed to the irradiation head 10 together with its drive mechanism. It has been incorporated. The collimator 19 has a hole 43 (radiation lead-out hole) for further thinning the radiation that has passed through the movable collimator 13.

As will be described later in detail, the collimator 19 can swing about a fulcrum on its central axis and can be positioned at any swing position. Furthermore, the fulcrum position of the swing is
It is the apex S of the radiation cone. The center line 29 of the collimator hole 43 is on a straight line connecting the apex S of the radiation cone and the isocenter so that the dose distribution of the radiation emitted from the collimator hole 43 is constant at any position of the swing. Exists in. Here, the radiation ray cone is a radiation beam emitted from the target 7, and its apex is the radiation position of the target 7. If the point radiation source is a point radiation source, the position of the point itself is the surface radiation. If it is a source, it means the center position of the surface.

FIG. 3 shows only the swinging mechanism of the collimator 19 out of the structure inside the housing 24 containing the collimator 19.

In the figure, there is an XY table 54 comprising a Y-direction table 34 and an X-direction table 36. The Y-direction table 34 is driven by a drive mechanism (not shown) and the X-direction table 36 is driven by a drive mechanism P. It is like this.

A collimator 19 is arranged on the upper surface of the X-direction table 36 via a spherical bearing 71. The spherical bearing 71 rotatably supports the lower portion of the collimator 19, so that the collimator 19 can swing about the spherical bearing 71.

The collimator 19 is inserted and positioned in the tubular member 70, and the spherical bearing 71 is attached to the tubular member 70. As a result, the collimator 1
9 can be attached and detached without being restricted by the spherical bearing 72.

The collimator 19 is attached and detached by moving the collimator 19 in the axial direction through a hole 32 provided in the XY table 54.

On the other hand, the cylindrical member 70 in which the collimator 19 is inserted has three link mechanisms L on the outer peripheral surface at the substantially center thereof.
Of the link mechanism L is fixed to the inner wall surface on the upper surface side of the housing 24. Each of these link mechanisms L regulates the follow-up of the movement of the collimator 19 with the movement of the XY table 54 as it is. It becomes possible to swing so as to match 29).

The invention relating to such a configuration has already been filed by the present applicant, and for details thereof, refer to Japanese Patent Application Nos. 4-25799 and 5-12410. I want to.

Further, FIG. 1 shows an attaching / detaching mechanism of the collimator 19 added to the above-mentioned structure. In addition,
In the figure, part of the configuration shown in FIG. 3 is omitted for ease of explanation. Further, FIG. 4 is a plan view seen from the AA line side of FIG. 1.

First, as shown in FIG. 5, the collimator 19 has a groove 35 formed in a part of the outer circumference thereof along the circumferential direction.
have. Further, the cylindrical member 70 for storing the collimator 19 is formed with a groove extending in a direction intersecting with the central axis in a part of the outer periphery thereof, and the groove is the collimator 19 described above.
It is configured to expose a part of the groove 35.

There is a detachable lever 40 inserted in the groove of the tubular member 79, and this detachable lever 40 is also inserted into the groove 35 of the collimator 19 at the same time. As a result, the movement of the collimator 19 in the axial direction is restricted by the attachment / detachment lever 40, and the storage state in the tubular member 79 is maintained.

This detachable lever 40 is used for the X-direction table 3
It is supported on 8 and its axial direction (B direction in the figure)
It can be slid on. When the sliding lever 40 is slid to the left in the figure in the B direction, the recess 53 is positioned so as to face the groove 35 of the collimator 19.
Are formed. That is, when the attachment / detachment lever 40 is slid in this manner, the locking of the collimator 19 by the attachment / detachment lever 40 is released, and the collimator 19 can be moved in the axial direction. That is, the collimator 19 can be attached to and detached from the tubular member 70 that is configured integrally with another mechanism.

The sliding lever 40 is supported by the cylindrical member 7
It is supported on the X-direction table 38 by the supporting members 36 and 37 provided at 0 and a swinging mechanism H described later.

The swing mechanism H comprises a tubular member 45,
This tubular member 45 is a tubular member 7 that houses the collimator 19.
It is fixed to the plate member 49 fixed to 0. And
A ball plunger 56 is provided in the cylindrical member 45 in a direction orthogonal to the sliding lever 40.

The ball plunger 56 is always in contact with the sliding lever 4 even when the sliding lever 40 is moved in the B direction in the figure.
A biasing force works on the 0 side. When the sliding lever 40 reaches the position for locking the collimator 19 and the position for unlocking the collimator 19, the sliding lever 40 is positioned in the grooves 58a, 58b provided in the sliding lever 40.

This makes it possible to recognize the mounting and releasing of the collimator 19 by the so-called click action sensed when the sliding lever 40 is operated.

Further, a shaft member 47 capable of swinging with respect to the Y-direction table 36 is inserted in the cylindrical member 45 of the swing mechanism H, and the cylindrical member 45 is axially movable with respect to the shaft member 47. It can move in the direction (C direction in the figure).

The reason why the cylindrical member 45 can be swung in this way is that the collimator 19 can be swung through the plate member 49 so that the sliding lever 40 can be constantly supported. Is.

In the vicinity of the slide lever 40, there is provided a safety lock device 62 which can be engaged with the collar portion 40A formed on the slide lever 40. By operating the safety lock device 62, it is possible to prevent the detachable lever 40 from being unintentionally moved in the direction of the arrow B (particularly the left side) due to the swing of the collimator 19.

Next, the operation will be described.

When the sliding lever 40 is at the position shown in FIG. 4, the concave portion 53 is separated from the groove 35 of the collimator 19 and therefore is inserted into the groove 35 of the collimator 19. Therefore, the collimator 19 is stored in the tubular member 70 and is driven by the peripheral drive mechanism.

Next, when the sliding lever 40 is slid in the direction of arrow B (left side in the drawing) from the state of FIG. 4, the sliding lever 4
0 moves in the hole 46 of the tubular member 45, and the ball plunger 56 of the tubular member 45 moves into the groove 5 provided in the sliding lever 40.
It comes to come off from 8a. Then, when it is further moved, the groove 58b moves to the position of the ball plunger 56, and the recess 53 provided in the sliding lever 40 is released from the groove 35 of the collimator 19. That is, the locking of the sliding lever 40 with respect to the collimator 19 is released.

Therefore, the collimator 19 can be moved in its axial direction, and is disengaged from the tubular member 70 that stores it.

According to the stereotactic radiotherapy apparatus constructed as described above, the collimator 19 in the normal state has the rod (sliding lever) inserted in the groove 35 formed on the outer periphery of the collimator 19 at right angles to the central axis. By the locking of 40), the movement in the direction of the central axis is restricted and the mounting state on the adjusting mechanism is maintained.

Then, by moving the rod (sliding lever 40) k in the axial direction, the collimator 1
The insertion of 9 into the groove 35 can be released.

Therefore, the collimator 19 which has been regulated by the rod (sliding lever 40) until then can be moved in the direction of the central axis thereof.
9 can now be removed from its adjusting mechanism.

After that, by performing the reverse operation to the above, another collimator having a different diameter of the radiation guiding hole can be mounted in the adjusting mechanism.

Therefore, although the adjusting mechanism for the collimator 19 is provided, the collimator 19 can be easily replaced with a simple structure.

Further, in this embodiment, since the rod (sliding lever 40) is supported on the XY table 54 while being restricted from moving in the other directions except its axial movement, The rod (sliding lever 40) can regulate the minute rotation of the collimator 19.

The collimator 19 is supported by the link mechanism L, but the rod (sliding lever 40) can surely prevent the minute rotation in the arrow direction E shown in FIG. 4 from occurring easily. Also plays.

In the above-mentioned embodiment, the link mechanism L is used as the adjusting mechanism for adjusting the swing of the collimator 19 so that the radiation source is positioned on the extension line of the central axis of the radiation guiding hole 43. Needless to say, the adjustment mechanism is not necessarily limited to such a link mechanism L, and the adjustment mechanism may be configured by another mechanism.

[0051]

As is apparent from the above description,
According to the stereotactic radiotherapy apparatus of the present invention, the collimator can be easily replaced with a simple structure, even though the collimator adjustment mechanism is provided.

[Brief description of drawings]

FIG. 1 is a main part configuration diagram showing an embodiment of a stereotactic radiotherapy apparatus according to the present invention.

FIG. 2 is an overall configuration diagram showing an embodiment of a stereotactic radiotherapy apparatus according to the present invention.

FIG. 3 is a main part configuration diagram showing an embodiment of a stereotactic radiotherapy apparatus according to the present invention.

FIG. 4 is a plan view seen from the AA line side of FIG.

FIG. 5 is a perspective view showing an embodiment of a collimator used in the stereotactic radiotherapy apparatus according to the present invention.

[Explanation of symbols]

 19 Collimator 40 Sliding lever (rod) 43 Radiation lead-out hole

Claims (1)

[Claims] 1. An adjusting mechanism for irradiating radiation from a radiation source through a collimator, and adjusting the swing of the collimator so that the radiation source is positioned on an extension line of the central axis of the radiation guiding hole. In the stereotactic radiotherapy apparatus provided with, the collimator is configured to be detachable from the adjusting mechanism by moving in the central axis direction, and is formed on the outer periphery of the collimator orthogonal to the central axis. The movement of the rod in the central axis direction is restricted by the locking by the rod inserted into the groove, and the rod is supported by the adjusting mechanism, and
A stereotactic radiotherapy apparatus, wherein the collimator can be moved in the axial direction so as to release the locking by being inserted into the groove.