JP2765025B2 - Radiation therapy control device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a radiotherapy control apparatus, and more particularly to adjustment of a radiation irradiation position of a high energy radiotherapy machine.

2. Description of the Related Art Conventionally, high-energy radiation therapy machines have a mechanism that cannot follow a patient who is undergoing radiation irradiation, even if the body moves slightly due to respiration or the like, particularly if it moves back and forth in the body axis direction. Was. That is, even if the irradiation position of the radiation to the patient changes, it cannot cope with the change.

Such a conventional high-energy radiation therapy machine does not have a mechanism for following the patient's longitudinal movement in the body axis direction. Therefore, even if the movement in the body axis direction is slightly caused by breathing or the like, the radiation is maintained under a fixed irradiation condition. Is continued, so that there is a disadvantage that healthy tissue is irradiated with extra radiation.

In addition, by adding a respiratory interlocking mechanism, in the case of a mechanism that irradiates radiation only when the patient moves to the most static state during exhalation and inhalation, the irradiation time becomes longer and the patient is greatly affected. There was an inconvenience that it would have to be painful.

SUMMARY OF THE INVENTION The present invention has been made in order to eliminate the above disadvantages of the related art, and has as its object to provide a radiotherapy control apparatus capable of realizing an advanced automatic matching function and improving the treatment accuracy. .

The radiotherapy control device according to the present invention is a radiotherapy control device that controls irradiation of radiation from a radiation head to a patient to be irradiated, and a detecting unit that detects a moving amount of the patient in a body axis direction. Moving means for moving the irradiation position of the radiation from the irradiation head in accordance with the moving amount detected by the detecting means.

Next, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of one embodiment of the present invention. In the figure, a light source 2 placed in an irradiation head 1 of a high-energy radiation therapy machine is a CCD (charge coupled device) line sensor (hereinafter referred to as a line sensor) 3 attached to the body surface of a treatment patient to be irradiated. Is irradiated with scanning light.

The line sensor 3 sends position information indicating the position irradiated by the scanning light from the light point source 2 to an incident position reading mechanism (hereinafter referred to as a reading mechanism) 4. The position information is read by the reading mechanism 4 into a digital value.

Here, assuming that the irradiation condition of the high-energy radiation therapy machine is given when the scanning light from the light point source 2 irradiates the center point 31 of the line sensor 3, the body axis movement due to the respiratory movement of the treatment patient Is determined by a value calculated from the position information changed by the displacement of the line sensor 3.

That is, the position information when the scanning light from the light point source 2 is applied to the center point 31 of the line sensor 3 is stored in the center coordinate storage mechanism 5, and the position information is stored at the body axis transition point 32 due to the movement of the body axis of the treatment patient. The positional information when the scanning light from the light point source 2 is irradiated is stored in the displacement coordinate storage mechanism 6.

The difference calculation mechanism 7 calculates the difference between the center position coordinate value stored in the center coordinate storage mechanism 5 and the body axis shift coordinate value stored in the movement coordinate storage mechanism 6, that is, the body axis displacement, and calculates the body axis displacement. The amount is sent to the collimator opening / closing control mechanisms 8 and 9.

The collimator opening and closing control mechanisms 8 and 9 control the collimator opening and closing mechanisms 10 and 11 in the irradiation head 1 based on the body axis displacement amount from the difference calculation mechanism 7 to correct the irradiation condition of the irradiation head 1.

Assuming that the body axis displacement amount from the difference calculation mechanism 7 is Δ, the collimator opening / closing control mechanism 8 corrects the irradiation condition by the body axis displacement amount of −Δ, and the collimator opening / closing control mechanism 9 irradiates only the body axis displacement amount of + Δ. Correct the condition.

The collimator opening / closing mechanisms 10 and 11 in the irradiation head 1 are controlled by collimator opening / closing control mechanisms 8 and 9, respectively, and maintain appropriate irradiation conditions of the irradiation beam.

FIG. 2 is a schematic diagram showing the relationship between the light source 2 and the line sensor 3 shown in FIG. FIG. 2A is a view of the treatment patient 12 as viewed from the side, and FIG. 2B is a view of the treatment patient 12 as viewed from the head side.

In these figures, the positional relationship between the irradiation port of the irradiation head 1 and the tumor 13 in the body of the treatment patient 12 is generally called a distance between source tumors, and the distance is kept constant (1 m to 80 cm). ing.

This is because, when the irradiation condition at the position of the in-vivo tumor 13 is determined, it is necessary to calculate and obtain a mechanical stop condition for physically opening and closing the collimator opening and closing mechanisms 10 and 11 in the irradiation head 1.

In addition, the distance between the light source 2 and the line sensor 3 is determined by detecting the movement of the treatment patient 12 in the body axis direction as a movement at a position where the in-vivo tumor 13 exists, and accurately providing feedback as a collimator opening / closing condition. Since it is necessary to multiply, it is adjusted to be equivalent to the distance between the source tumors.

Therefore, the beam point source 14 of the irradiation head 1 and the internal tumor 13
Is equal to the distance between the light source 2 and the line sensor 3.

FIG. 3 is a view showing the transition state of the line sensor 3 and the opening / closing state of the collimator opening / closing mechanisms 10 and 11 in FIG. In the figure, the movement of the treatment patient 12 in the body axis direction, that is, the position of the line sensor 3 and the opening / closing state of the collimator opening / closing mechanisms 10 and 11 when the body axis displacement is zero, and when the body axis displacement is Δ 3 shows the position of the line sensor 3a and the open / closed state of the collimator opening / closing mechanisms 10a and 11a.

The operation of the embodiment of the present invention will be described with reference to FIGS.

During the irradiation of the treatment patient 12, the movement in the body axis direction occurs due to the respiratory movement, and the line sensor 3
If it has moved to the position of 3a, the irradiation position of the scanning light from the light point source 2 on the line sensor 3a moves to the transition point 32a,
The position information is stored in the transition coordinate storage mechanism 6.

Since the center position coordinate value of the center point 31a is stored in the center coordinate storage mechanism 5, the difference calculation mechanism 7 stores the center position coordinate value stored in the center coordinate storage mechanism 5 and the displacement coordinate storage mechanism 6. The body axis displacement amount Δ is calculated from the body axis displacement coordinate value and the body axis displacement amount Δ is used as the collimator opening / closing control mechanism 8, 9.
To send to.

The collimator opening / closing control mechanism 8 corrects the irradiation condition by the body axis displacement amount of −Δ by the body axis displacement amount Δ from the difference calculation mechanism 7 so that the collimator opening / closing mechanism 10 in the irradiation head 1 is corrected.
The collimator opening / closing control mechanism 9 controls the collimator opening / closing mechanism 11 in the irradiation head 1 so that the irradiation condition is corrected by the body axis displacement of + Δ based on the body axis displacement Δ from the difference calculation mechanism 7. The irradiation conditions of the irradiation head 1 are corrected.

As a result, in the irradiation head 1, the collimator opening / closing mechanism 10 is closed by the body axis displacement amount Δ and the collimator opening / closing mechanism 10 is closed.
At position a, the collimator opening A before movement in the body axis direction
From 0, the collimator opening A1 narrows down to the post-movement collimator opening A1, and the collimator opening / closing mechanism 11 opens by the body axis displacement amount Δ to the position of the collimator opening / closing mechanism 11a, from the collimator opening B0 before moving in the body axis direction. It increases to the collimator opening B1 after the movement.

Therefore, the irradiation port 15 of the irradiation head 1 moves to the irradiation port 15a, and the irradiation condition of the irradiation head 1 is corrected according to the movement of the treatment patient 12 in the body axis direction. As a result, the positional relationship between the irradiation position from the beam point source 14 to the in-vivo tumor 13 and the in-vivo tumor 13 is kept substantially constant.

In this way, the difference calculation mechanism 7 calculates the body axis displacement amount based on the position information from the line sensor 3 that changes according to the movement of the treatment patient 12 in the body axis direction, and opens and closes the collimator according to the body axis movement amount. By controlling the mechanisms 10 and 11 to move the irradiation port 15 of the irradiation head 1, the treatment patient 12
The irradiation condition can be automatically corrected according to the movement of the body in the body axis direction, an advanced automatic matching function can be realized, and the treatment accuracy can be improved.

Advantageous Effects of the Invention As described above, according to the present invention, the amount of movement of a patient in the body axis direction is detected, and the irradiation position of the radiation from the irradiation head is moved according to the amount of movement. This has the effect of realizing a simple automatic matching function and improving the treatment accuracy.

[Brief description of the drawings]

FIG. 1 is a block diagram showing the configuration of one embodiment of the present invention, FIG. 2 is a schematic diagram showing the relationship between the light source and the line sensor of FIG. 1, and FIG. 3 is a diagram of the line sensor of FIG. It is a figure which shows the transition state and the opening / closing state of a collimator opening / closing mechanism. Description of Signs of Main Part 1 Irradiation Head 2 Light Source 3,3a CCD Line Sensor 4 Incident Position Reading Mechanism 5 Center Coordinate Storage Mechanism 6 Transition Coordinate Storage Mechanism 7 Difference Computing mechanism 8,9 …… Collimator opening / closing control mechanism 10,11,10a, 11a …… Collimator opening / closing mechanism

Claims (1)

(57) [Claims] 1. A radiotherapy control device for controlling irradiation of radiation from an irradiation head to a patient to be irradiated, comprising: detection means for detecting an amount of movement of the patient in the body axis direction; Moving means for moving the irradiation position of the radiation from the irradiation head in accordance with the moving amount.