JP3240655B2 - X-ray simulator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used in connection with a radiotherapy apparatus for performing treatment by irradiating radiation, and simulates therapeutic radiation irradiation to a treatment site prior to radiotherapy to prepare a treatment plan. An X-ray simulator to be determined.

[0002]

2. Description of the Related Art An X-ray simulator irradiates X-rays instead of therapeutic radiation to simulate radiation irradiation to a treatment site. That is, X-rays are irradiated in the same direction and irradiation field as the radiation to be actually irradiated, and a plan is determined from which direction and in what irradiation field. Therefore, the X-ray tube can be rotated so that X-rays can be emitted from an arbitrary irradiation direction, and a wire collimator is arranged in a rectangular shape in front of the X-ray tube, and its long axis and short axis are independent. It can be changed to.

A patient who actually needs treatment is irradiated with X-rays from such an X-ray tube, the transmitted X-rays are made incident on an image intensifier, converted into a video signal by a television camera, and displayed on a monitor device. Then, the shadow (image) of the wire collimator is displayed on the screen together with the affected part of the patient. The irradiation field of the therapeutic radiation is represented by a rectangular wire collimator, and the irradiation field can be changed by moving the wire collimator. In this way, by the image of the wire collimator and its movement, it is possible to determine an irradiation field in which only the affected part is irradiated with radiation most efficiently.

[0004]

However, the conventional X-ray simulator is based on the premise that the irradiation field of therapeutic radiation is rectangular as described above, and has a problem that it cannot cope with other shapes. is there.

In other words, in recent years, a radiation therapy apparatus in which a plurality of radiation shielding blocks (leaves) are combined and an irradiation field can be formed into an arbitrary shape by freely moving these radiation shielding apparatuses is becoming popular. The problem is that they cannot deal with this.

[0006] In view of the above, an object of the present invention is to provide an X-ray simulator improved so as to be able to simulate irradiation of therapeutic radiation in any irradiation field shape.

[0007]

In order to achieve the above object, in the X-ray simulator according to the present invention, instead of disposing a wire collimator representing the shape of an irradiation field in front of the X-ray tube, an actual radiation of therapeutic radiation is used. A figure representing the irradiation field shape is electronically created and displayed superimposed on the X-ray transmission image of the patient, and the electronic figure is displayed on the basis of information input by arbitrarily operable coordinate input means. It is characterized in that it is changed in accordance with an actually possible change in the shape of the irradiation field. According to this, the irradiation field figure superimposed and displayed on the X-ray image of the patient can be electronically created and changed by the arbitrarily operable coordinate input means. Is very easy, it can simulate the irradiation field no matter what the actual irradiation field shape is, and optimizes the irradiation field shape to match the shape of the affected area to be treated by irradiation. Can be easily determined.

[0008]

An embodiment of the present invention will be described below in detail with reference to the drawings. FIG. 1 shows an embodiment of the present invention. As shown in FIG. 1, a patient 1 to be subjected to radiation treatment is laid on a bed top 2 and an X-ray tube 3 is provided.
More X-rays are emitted. This X-ray tube 3
In an actual radiation therapy apparatus, the radiation source can be rotated so that radiation can be emitted from an arbitrary direction, and is held rotatably by a mechanism (not shown) so that the angle with respect to the patient 1 can be made arbitrary. It has become.

The X-rays emitted from the X-ray tube 3 pass through the patient 1 and enter the image intensifier 4, where the X-ray transmission image is converted into a visible light image.
The video signal is further converted by the television camera 5 into a video signal. This video signal is sent to the image display device 7 through the adder 6, and the image display device 7 displays an X-ray transmission image of the patient 1. This X-ray transmission image is, for example, as shown in FIG. 2A, and the affected part is shown as indicated by oblique lines.

On the other hand, the image processing device 8 generates a graphic signal corresponding to the irradiation field of the radiation therapy apparatus actually used. Here, it is assumed that a signal representing a graphic as shown in FIG. 2B is generated, assuming that a multi-leaf radiation therapy apparatus is used. Since this signal is added to the video signal in the adder 6, the X-ray transmission image (A in FIG. 2) and the irradiation field figure (FIG.
2) is superimposed, and an image as shown in FIG. 2C is displayed.

Here, in the multi-leaf type radiotherapy apparatus, a large number of radiation shielding leaves are arranged on the left and right so that they can move independently to the left and right, and the shape of the gap can be set arbitrarily. Has become. Since the therapeutic radiation is irradiated from this gap, the gap defines the irradiation field. Therefore, the graphic represented by the graphic signal generated electronically by the image processing device 8 is as shown in FIG. 2B corresponding to each leaf. Then, by operating the mouse 9 (or another coordinate input device such as a trackball), the figure representing each of the leaves is moved to the left and right as in the case of moving the leaves, and the gap between them is arbitrarily determined. You can do it.

While observing the X-ray transmission image displayed on the image display device 7 and the irradiation field figure displayed thereon,
The operation of the mouse 9 is performed so that the irradiation field exactly surrounds the affected area (shaded area). Then, if the patient 1 is irradiated with the therapeutic radiation from the position of the X-ray tube 3 in the set irradiation field at this time, only the affected part can be irradiated, so that the most appropriate radiation treatment can be performed. You can do it.

In practice, first, the operator operates the image display device 7.
While viewing the X-ray transmission image, the angles of the bed top plate 2 and the X-ray tube 3 are adjusted so that the treatment site of the patient 1 enters the field of view. Next, the operator operates the mouse 9 while observing the image display device 7 to determine the opening degree (the size of the gap) of each leaf. By such X-ray simulation,
The treatment plan is established, and if the treatment parameters determined in this way are input to the radiation treatment apparatus by any method, radiation treatment according to the set plan can be performed.

When the X-ray simulator and the radiotherapy apparatus are connected on-line, the radiotherapy apparatus automatically sets up based on the parameters and sets the isocenter (origin of patient 1) to the X-ray simulator and the radiotherapy apparatus. By combining with the device, it is possible to proceed to the radiation treatment as planned.

In this embodiment, an irradiation field projector 10 is provided in case such online transfer of treatment parameters is not possible. This irradiation field projector 10 is X
It is arranged at the same position and angle as the X-ray tube 3 in place of the X-ray tube 3, and includes a light source 11 and a liquid crystal plate 12.
A graphic signal representing the set irradiation field is sent from the image processing device 8 to the liquid crystal plate 12, and the graphic is displayed.

Therefore, when the treatment plan is determined as described above, the shape of the set irradiation field is changed by the light to the patient 1.
Will be projected onto the body surface. The marking is performed on the body surface of the patient 1 by tracing the projected figure. The patient 1 is set on the radiotherapy apparatus, and the position and angle of the radiation source of the radiotherapy apparatus are determined based on the position and angle of the X-ray tube 3 in the X-ray simulator. By adjusting the irradiation field of the treatment device, radiation treatment can be performed as planned.

Although the above description has been made of the case where a multi-leaf type radiotherapy apparatus is used, the radiation therapy apparatus of the type in which a radiation shielding block is arbitrarily set to determine the irradiation field of therapeutic radiation is also used. A signal representing a figure corresponding to the shielding block may be electronically generated by the image processing device 8 and moved by the mouse 9, so that a complete simulation is possible.

[0018]

As described above, according to the X-ray simulator of the present invention, the irradiation field graphic displayed on the X-ray image of the patient is electronically created, and is changed to an arbitrary shape. It is very easy to do this regardless of the actual shape of the therapeutic radiation field in a multi-leaf type radiotherapy device or a type of radiotherapy device where a radiation shielding block can be arbitrarily placed. , You can simulate it.

[Brief description of the drawings]

FIG. 1 is a block diagram of one embodiment of the present invention.

FIG. 2 is a diagram showing each image in the embodiment.

[Explanation of symbols]

 Reference Signs List 1 patient 2 bed top plate 3 X-ray tube 4 image intensifier 5 television camera 6 adder 7 image display device 8 image processing device 9 mouse 10 irradiation field projector 11 light source 12 liquid crystal plate

Claims (1)

(57) [Claims] 1. An X-ray generating means, an X-ray receiving means for receiving an X-ray and generating an image signal, and an X-ray receiving means for transmitting the image signal
Image display means for displaying a line transmission image, arbitrarily operable coordinate input means, and generating a graphic signal corresponding to the actual irradiation field shape of the therapeutic radiation and based on information input from the coordinate input means Image processing means for changing the shape of the figure in accordance with an actually possible change in the irradiation field shape, and means for displaying the figure on the X-ray transmission image in the image display means. A featured X-ray simulator.