JP2885304B2 - Radiotherapy equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radiotherapy apparatus, and more particularly to a radiotherapy apparatus capable of irradiating radiation toward a center of rotation while moving with respect to the center of rotation.

[0002]

2. Description of the Related Art A schematic structure of a linac in a three-dimensional concentrating radiation therapy apparatus is shown in FIG. As shown in FIG. 14, the three-dimensional concentrating radiation therapy apparatus includes a radiation irradiator 1, C
Mold support arm 2, arm support 3, power supply 4, X-ray applicator 5, opposing plate 6, treatment table 10, fixed fixture 11
And a head attachment 12. The fixed fixture 11
Is attached to the treatment table 10, and the head attachment 12 is attached to the fixed attachment 11. A patient (subject) 13 is placed on the treatment table 10, and the head of the patient 13 is fixed with a head fixture 12.

In FIG. 14, reference numeral O denotes a center of rotation, and the C-shaped support arm 2 can rotate at a rotation angle ψ and a rotation angle φ with reference to the center of rotation O. That is, the X-ray applicator 5, which is a radiation irradiation source, is rotated with respect to the rotation center O, and the rotation center O is always maintained even when the radiation irradiation position is moved.
Radiation can be emitted.

[0004] The following operation is performed in the three-dimensional concentrating radiation therapy apparatus configured as described above.

[0005] First, in order to perform radiation therapy, a patient 13 is required.
Is fixed to the head. Next, based on the radiation treatment plan, the positional relationship between the treatment site (target) on the head of the patient 13 and the head fixture 12 is determined. Next, the patient 13 is placed on the treatment table 10, and the head attachment 12 is attached to the fixed attachment 11. The fixed attachment 11 is provided with a movable mechanism capable of adjusting the attachment position of the head attachment 12, and the attachment position of the head attachment 12 is set at a position where the treatment site and the rotation center O overlap in the radiation irradiation path. Adjusted.

When the radiation treatment is started, the radiation irradiator 1 is rotated at a rotation angle ψ and a rotation angle φ along a trajectory based on the above-described treatment plan, and the radiation ( X-rays) are focused on the treatment site. The irradiation of the radiation causes treatment of the patient. In this radiation treatment, radiation that penetrates the patient 13 and leaks to the surroundings is shielded by the opposing plate 6.

[0007]

The following points are not taken into consideration in the above-described three-dimensional converging radiation therapy apparatus.
The rotational movement and rotational speed of the radiation irradiator 1 are controlled by a rotational drive system. However, in the case of a human error operation that deviates from the radiation treatment plan or an unexpected failure of the rotary drive system, the moving position of the radiation irradiation unit 1, that is, the radiation irradiation position cannot be known. For this reason, it is predicted that excessive radiation will be applied to the treatment site of the patient 13 or other sites, and there is a problem in safety.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and detects a radiation irradiation position during irradiation, and sets a moving path, a moving speed, and the like of the radiation irradiation position in advance. It is an object of the present invention to provide a radiotherapy apparatus capable of appropriately controlling radiation irradiation when a deviation from a planned plan is performed.

[0009]

In order to achieve the above object, according to the present invention, there is provided a radiotherapy apparatus capable of irradiating radiation toward the rotation center while moving with reference to the rotation center. A reference movement of a radiation irradiation position, which is disposed in the radiation irradiation path near the rotation center, has a portion with high radiation transmittance and a portion with low radiation transmittance, and is formed by the portion with high or low radiation transmittance. A coordinate body having a path, irradiation position reading means for reading information on a reference movement path of the coordinate body and information on a movement path of an actual radiation irradiation position from radiation transmitted through the coordinate body, and reading by the irradiation position reading means Irradiation position determining means for determining whether or not the radiation irradiation position is moving along the reference movement path based on the received information, and an output signal of the irradiation position determining means Based characterized by comprising irradiation control means for controlling the radiation dose, the by.

According to a second aspect of the present invention, in the radiotherapy apparatus according to the first aspect, the coordinate body partially surrounds the rotation center and does not transmit radiation before passing through the rotation center. And a cylindrical shape that transmits the radiation after passing through the rotation center.

According to a third aspect of the present invention, in the radiotherapy apparatus according to the first or second aspect, a portion of the coordinate body having a low radiation transmittance is formed of a linear shielding material. The shielding member forms a reference movement path of the radiation irradiation position.

According to a fourth aspect of the present invention, there is provided a radiotherapy apparatus capable of irradiating radiation toward the rotation center while moving on the basis of the rotation center, wherein the radiation treatment apparatus is disposed in the radiation irradiation path near the rotation center. A coordinate body having a portion having a high radiation transmittance and a low portion, and a plurality of the high or low radiation transmittance portions being regularly arranged alternately in the moving direction of the radiation irradiation position; Information reading means for reading information of a portion where the radiation transmittance is high or low from the radiation to be read, counting means for counting information read by the information reading means, and counting by the counting means. Count value determining means for comparing the count value with a preset reference count value to determine whether or not there is a deviation between both count values; And irradiation control means for controlling the radiation dose based on the output signal of the judging means, characterized by comprising a.

According to a fifth aspect of the present invention, there is provided a radiotherapy apparatus capable of irradiating radiation toward the rotation center while moving with respect to the rotation center, wherein the radiation treatment apparatus is disposed in the radiation irradiation path near the rotation center. A coordinate body having a plurality of parts with high radiation transmittance and a low part, and wherein the distance between the high and low parts of the radiation transmittance is changed along the moving direction of the radiation irradiation position, and the coordinate body Information reading means for reading information of the distance between the high or low distance between the radiation parts of the coordinate body from the radiation transmitted through, and calculating the distance based on the information read by the information reading means, Interval determining means for determining whether there is a difference between the calculated value and a preset reference interval value, and an illumination controlling the radiation dose based on an output signal of the interval determining means. Characterized by comprising a control means.

According to a sixth aspect of the present invention, there is provided a radiation therapy apparatus capable of irradiating radiation toward the rotation center while moving with respect to the rotation center, wherein the radiation treatment apparatus is disposed in the radiation irradiation path near the rotation center. A code area formed by a part having a high radiation transmittance, a part having a low radiation transmittance, or a combination thereof, and having coded movement information such as a movement amount and a movement time is regularly arranged along the movement direction of the radiation irradiation position. A coordinate body, information reading means for reading encoded movement information of a code area of the coordinate body from radiation transmitted through the coordinate body, and decoding which can be compared and determined from the encoded movement information read by the information reading means. Decoding determination means for generating movement information and comparing the generated decoded movement information with predetermined reference movement information to determine whether there is a difference between the two pieces of information. Characterized in that and a radiation control means for controlling the radiation dose based on the control signal outputted from the decoding decision means.

[0015]

In the radiotherapy apparatus according to any one of the first to third aspects of the present invention, the irradiated radiation passes through the coordinate body on which the reference movement path of the radiation irradiation position is displayed. The radiation transmitted through the coordinate body has information on the reference movement path obtained from the coordinate body and information on the movement path of the radiation irradiation position of the actually irradiated radiation. These pieces of information are read by the irradiation position reading unit, and from the read information, it is determined by the irradiation position determining unit whether the radiation irradiation position is moving on a moving path (trajectory) as planned. If the radiation irradiation position is a movement that deviates from the plan, the radiation irradiation control means stops radiation irradiation, for example, thereby ensuring patient safety.

In the radiotherapy apparatus according to the fourth aspect of the present invention, the irradiated radiation penetrates a coordinate body in which a plurality of parts having a high or low radiation transmittance are regularly arranged alternately in the moving direction of the radiation irradiation position. I do. The radiation transmitted through the coordinate body has information on a portion with a high or low radiation transmittance obtained from the coordinate body. The number of information is increased by the movement of the radiation irradiation position, and the number of information is read by the information number reading means and counted by the counting means. This count value is compared with a reference count value set in advance by the count value determination means, and the count value determination means determines whether the radiation irradiation position is moving at a rotation angle, a movement amount, a movement speed, etc. according to the radiation treatment plan. Is determined. If the radiation irradiation position is a movement that deviates from the plan, the irradiation control means stops radiation irradiation, for example, thereby ensuring patient safety.

In the radiotherapy apparatus according to the fifth aspect of the present invention, the irradiated radiation passes through a coordinate body in which the distance between the parts with high radiation transmittance or the distance between the parts with low radiation transmittance changes along the moving direction of the radiation irradiation position. I do. The radiation transmitted through the coordinate body has information on the distance between the parts with high or low radiation transmittance obtained from the coordinate body. This information is read by the information reading means, and the distance is calculated by the interval determining means based on the read information. In the interval determination means, the calculated value is compared with a preset reference interval value, and it is determined whether the radiation irradiation position is moving at a planned rotation angle, moving amount, moving speed, or the like. If the result of this determination is that the radiation irradiation position is a movement that deviates from the plan, a control signal is output from the interval determination means to the irradiation control means. Based on this control signal, the irradiation control means stops, for example, the irradiation of radiation, thereby ensuring patient safety.

In the radiotherapy apparatus according to the present invention, the radiation to be irradiated is formed at a portion having a high radiation transmittance, at a portion having a low radiation transmittance, or a combination of both, and the rotation angle, the moving amount, and the moving speed are provided. A code area having coded movement information such as the above penetrates a coordinate body that is regularly arranged along the movement direction of the radiation irradiation position. The radiation transmitted through the coordinate body has the encoded movement information of the code area of the coordinate body. The encoded movement information is read by the information reading means, and the read encoded movement information is generated as decoded movement information that can be compared with the reference movement information by the decoding determination means. The generated decoded movement information is compared with the reference movement information by the decoding determination means, and it is determined whether the radiation irradiation position is moving based on the rotation angle, the moving amount, the moving speed, and the like according to the radiation treatment plan. If the radiation irradiation position is a movement that deviates from the plan, a control signal is output from the decoding determination unit to the irradiation control unit, and the irradiation control unit stops, for example, irradiation of radiation, thereby ensuring patient safety.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings.

Embodiment 1 FIG. 1 shows a schematic structure of a linac of a three-dimensional concentrating radiation therapy apparatus according to the present invention. The basic configuration is shown in FIG.
This is the same as the three-dimensional concentrating radiation therapy apparatus shown in FIG. That is, the three-dimensional concentrating radiation therapy apparatus includes a radiation irradiation unit (radiation irradiation position) 1, a C-shaped support arm 2, an arm support unit 3, a power supply unit 4, an X-ray applicator 5, an opposing plate 6, a treatment table 10, A fixed fixture 11 and a head fixture 12 are provided. The fixed fixture 11 is attached to the treatment table 10, and the head fixture 12 is attached to the fixed fixture 11. A patient 13 is placed on the treatment table 10, and the patient 1
The head of No. 3 is fixed by a head mounting tool 12.

In FIG. 1, symbol O is the center of rotation, symbols ψ and φ.
Is the rotation angle. The X-ray applicator 5 rotates with respect to the rotation center O, and can always emit radiation to the rotation center O even if the radiation irradiation position is moved.

According to the present invention, the three-dimensional condensing type radiation therapy apparatus includes a coordinate body 15 and a radiation detecting section (irradiation position reading means) 16.

The coordinate body 15 is fixed to the fixed fixture 11, and the coordinate body 15 is arranged in the radiation irradiation path near the center of rotation O. FIG. 1, FIG. 3 (A), (B)
As shown in FIG. 4 and FIG.
And a cylindrical shape (semi-spherical shape) that transmits the radiation after passing through the rotation center O without transmitting the radiation before passing through the rotation center O. Since the treatment site (the head in the present embodiment) of the patient 13 is inserted,
The central part of the coordinate body 15 is formed of a cavity. Coordinate body 15
Has a portion 15A having a high radiation transmittance and a portion 15B having a low radiation transmittance. Part 15B with low radiation transmittance
Is formed of a shielding material in the present embodiment, and the shielding material is formed in an elongated linear shape formed along the moving direction of the radiation irradiation position, that is, the moving direction of the radiation irradiation unit 1.

The portion 15B of the coordinate body 15 having a low radiation transmittance forms a reference moving path. This reference movement path is a coordinate path representing the path to which the radiation irradiation position is to be moved. In the radiation treatment plan, the movement path of the radiation irradiation position is set in accordance with the reference movement path.

The radiation detecting section 16 is located at a position facing the radiation irradiating section 1 with the rotation center O as a center.
(See FIG. 1). As shown in FIG. 2, the radiation detection unit 16 includes a detector 20. In this embodiment, the detector 20 is constituted by a one-dimensional sensor (line sensor) in which radiation detecting elements are arranged one-dimensionally in the moving direction of the radiation irradiation position. Radiation (X-rays) emitted from the X-ray applicator 5 of the radiation irradiating unit 1
Is transmitted, the transmitted radiation has information generated in a portion (reference movement path) 15B of the coordinate body 15 where the radiation transmittance is low. This information is read by the detector 20.

As shown in FIG. 2, the detector 20 is connected to a comparator 22 together with a threshold setting circuit 21. The comparator 22 is connected to an interlock control circuit 23. The interlock control circuit 23 controls the radiation dose, such as stopping irradiation, decreasing the dose, increasing the dose, etc., based on the information read by the detector 20. The control output signal of the interlock control circuit 23 is output to the power supply unit 4.

Next, an operation procedure and a method of controlling the radiation dose in the above-described three-dimensional concentrating radiation therapy apparatus will be described.

First, in order to perform radiotherapy, the patient 13
Is fixed to the head. Next, based on the radiation treatment plan, the positional relationship between the treatment site (target) on the head of the patient 13 and the head fixture 12 is determined. Next, the patient 13 is placed on the treatment table 10, and the head attachment 12 is attached to the fixed attachment 11. When the head attachment 12 is attached, the head of the patient 13 is positioned inside the coordinate body 15. Thereafter, the positional relationship of the radiation irradiation position, the treatment site on the head of the patient 13, the rotation center O, and the like is adjusted by a movable mechanism (not shown) of the fixed fixture 11.

When the radiation treatment is started, the radiation irradiator 1 is rotated at a rotation angle ψ and a rotation angle φ along a trajectory based on the aforementioned treatment plan, and the radiation narrowed down by the X-ray applicator 5 is The treatment site is irradiated intensively. The irradiation of the radiation causes treatment of the patient.

At this time, the radiation that has passed through the treatment site of the patient 13 and has passed through the coordinate body 15 is the information of the actual radiation irradiation position and the radiation of the part (reference movement path) 15B of the coordinate body 15 where the radiation transmittance is low. Have information. This information is read by the detector 20 of the radiation detector 16.

FIG. 5 shows a relationship between the irradiation projection image 20D and the detection unit 20 when the radiation having the information reaches the detection unit 20. In (A), a portion 1 having a low radiation transmittance of the coordinate body 15 is located substantially at the center of the irradiation projection image 20D.
The information 20D of 5B is located, and the information 20D coincides with the array position 20L of the radiation detection elements of the detection unit 20. That is, it means that the radiation irradiation position is being moved along the reference movement path, and in this case, the radiation detection element of the detection unit 20 is turned on (or turned off). vice versa,
In (B), a portion 15B of the coordinate body 15 having a low radiation transmittance is located at a position shifted from the center position of the irradiation projection image 20D.
20D is located, and the information 20D does not match the array position 20L of the radiation detection elements of the detection unit 20. That is, it means that the radiation irradiation position is not moved along the reference movement path, and in this case, the radiation detection element of the detection unit 20 is turned off (or turned on).

As described above, when the information 20D is read by the detector 20, the comparator 22 shown in FIG.
The output of 0 and the threshold value output from the threshold value setting circuit 21 are compared. When the deviation from the reference movement path exceeds a certain range, the comparator 22 outputs stop information (or decrease information) of the radiation dose to the interlock control circuit 23. Based on this output, the interlock control circuit 23 outputs a control signal to the power supply unit 4 to stop radiation irradiation (or to stop rotation driving of the radiation irradiation unit 1),
Irradiation is stopped.

In the radiotherapy apparatus configured as described above, the irradiated radiation passes through the coordinate body 15 on which the reference movement path of the radiation irradiation position 1 is displayed. The radiation transmitted through the coordinate body 15 has information 20C on the reference movement path obtained from the coordinate body 15 and information on the movement path of the radiation irradiation position of the actually irradiated radiation. These pieces of information are read by the irradiation position reading unit (detection unit 20), and the irradiation position determination unit (threshold setting circuit 21 and comparator 22) moves the irradiation position along a moving path (trajectory) as planned based on the read information. Is determined.
If the radiation irradiation position is a movement that deviates from the plan, the radiation irradiation control means (interlock control circuit 23) stops radiation irradiation, for example, thereby ensuring patient safety.

In the above embodiment, the portion 15 of the coordinate body 15 having a low radiation transmittance is the information 2 of the radiation irradiation position.
Although used as 0C, in the present invention, a portion 15A having a high radiation transmittance may be used as information of a radiation irradiation position.

Although a one-dimensional sensor is used as the detection unit 20 in the above embodiment, a semiconductor scintillator, a chamber, a fluorescent plate, or the like may be used as the detector 20 in the present invention.

Embodiment 2 FIG. 6 shows the structure of the coordinate body of the three-dimensional converging radiation therapy apparatus according to the present invention. Since the structure of the linac is the same as that of the first embodiment, the description of the second embodiment and the later-described embodiments will be omitted.

In the second embodiment, the coordinate body 15 is formed in a cylindrical shape, and the basic outer shape is the same as that of the first embodiment. Coordinate body 15 has low radiation transmittance (shielding material)
A plurality of 15Cs are regularly arranged at regular intervals along the moving direction of the radiation irradiation position. That is, the coordinate body 1
In 5, a plurality of portions 15 </ b> A having a high radiation transmittance and a portion 15 </ b> C having a low radiation transmittance are alternately and regularly arranged along the moving direction of the radiation irradiation position. The portion 15C of the coordinate body 15 where the radiation transmittance is low constitutes information on the rotation angle of the radiation irradiation position and information on the movement amount (or information on the reference movement path of the radiation irradiation position).

The detector 20 of the radiation detecting section 16 is constituted by a sensor capable of individually recognizing portions 15C of the coordinate bodies 15 arranged at a predetermined interval and having a low radiation transmittance. For example, a one-dimensional sensor in which radiation detection elements are one-dimensionally arranged in a direction orthogonal to the moving direction of the radiation irradiation position is used. In other words, the one-dimensional sensor can individually recognize the information (projected image) of the portion 15C of the radiation having a low radiation transmittance transmitted through the coordinate body 15 every time the radiation crosses the radiation detecting element.

The detector 20 is connected to a comparator 22 together with a threshold setting circuit 21 as shown in FIG. 7, and the comparator 22 is connected to an interlock control circuit 23 through a counter 24 and a computer 25. The counter 24 counts the number of pieces of information (information of the portion 15C having a low radiation transmittance) read by the detector 20. Threshold setting circuit 21 and comparator 2
In 2, the information of the predetermined radiation dose is selected (it is identified as the information of the portion 15C having a low radiation transmittance), and the counter 24 counts the number of the selected information. The memory device 26 is connected to the computer 25. The memory device 26 stores in advance a reference count value representing the number of information to be counted per predetermined treatment time based on the radiation treatment plan. In the calculator 25, the number of information counted by the counter 24 and the reference count value stored in the memory device 26 are compared in real time. When a difference occurs between the two values, the computer 25 outputs a control signal to the interlock control circuit 23, and the interlock control circuit 23 controls the radiation dose.

The operation procedure of the three-dimensional focusing radiotherapy apparatus of the present embodiment is the same as that of the first embodiment, and the method of controlling the radiation dose is described in the configuration. Omitted.

In the three-dimensional condensing type radiation therapy apparatus configured as described above, the irradiated radiation is coordinated such that a plurality of portions 15C having a low radiation transmittance are regularly arranged alternately in the moving direction of the radiation irradiation position. The radiation transmitted through the body 15 and transmitted through the coordinate body 15 has information on a portion 15C having a low radiation transmittance obtained from the coordinate body 15. The number of information increases as the radiation irradiation position moves, and the number of information is read by the information number reading means (detector 20) and counted by the counting means (counter 24). This count value is compared in real time with a reference count value set in advance by a count value determining means (a computer 25 and a memory device 26). It is determined whether the vehicle is moving at the moving speed or the like. If the radiation irradiation position is a movement that deviates from the plan, the irradiation control means stops radiation irradiation, for example, thereby ensuring patient safety.

Embodiment 3 FIG. 8 shows the structure of a coordinate body of a three-dimensional concentrating radiation therapy apparatus according to the present invention.

In the third embodiment, the coordinate body 15 has a cylindrical shape, and the basic outer shape is the same as that of the first embodiment. Coordinate body 15 has low radiation transmittance (shielding material)
15D is configured. This part 15 with low radiation transmittance
D is configured as a set of a straight line shielding portion 15d1 and a diagonal line shielding portion 15d2. The straight shielding portion 15d1 is formed along the moving direction of the radiation irradiation position, and is formed in a straight and elongated shape. The oblique line shielding portion 15d2 is formed along the moving direction of the radiation irradiation position, and is formed at an inclination angle at which the interval between the oblique line shielding portion 15d1 and the linear shielding portion 15d1 changes along the moving direction of the radiation irradiation position. Moreover, the oblique line shielding portion 15d2 is formed in a straight and elongated shape like the straight line shielding portion 15d1. The portion 15D of the coordinate body 15 having a low radiation transmittance constitutes information on the rotation angle of the radiation irradiation position and information on the movement amount (or information on the reference movement path of the radiation irradiation position).

The detector 20 of the radiation detecting section 16 is constituted by a sensor capable of simultaneously recognizing information of the straight line shielding section 15d1 and the oblique line shielding section 15d2 of the portion 15D having a low radiation transmittance. For example, a matrix sensor (two-dimensional sensor) in which radiation detection elements are arranged in a matrix direction, that is, two-dimensionally, is used.

The detector 20 is connected to an image memory device 27 as shown in FIG. 9, and this image memory device 27 is connected to an interlock control circuit 23 through a computer 25. The image memory device 27 stores the information read by the detector 20 (the linear shielding portion 15d of the portion 15D having a low radiation transmittance).
1 and information on the oblique line blocking unit 15d2) are stored in real time (or at predetermined time intervals) as image information. Calculator 2
The memory device 26 is connected to 5. The memory device 26 stores in advance a reference interval value indicating an interval (distance) to be taken between the straight line shielding unit 15d1 and the oblique line shielding unit 15d2 at every predetermined treatment time based on the radiation treatment plan. The calculator 25 calculates an interval L between the straight line shielding unit 15d1 and the oblique line shielding unit 15d2 from the image information stored in the image memory device 27 as shown in FIG. The reference interval value stored in the device 26 is compared in real time. When a difference occurs between the two values, the computer 25 outputs a control signal to the interlock control circuit 23, and the interlock control circuit 23 controls the radiation dose.

The operation procedure of the three-dimensional focusing radiotherapy apparatus of the present embodiment is the same as that of the first embodiment, and the method of controlling the radiation dose is described in the configuration. Omitted.

In the three-dimensional concentrating radiation therapy apparatus configured as described above, the radiation to be irradiated is the distance between the parts having a low radiation transmittance (the distance between the straight shielding part 15d1 and the oblique shielding part 15d2). L passes through the coordinate body 15 that changes along the moving direction of the radiation irradiation position. The radiation transmitted through the coordinate body 15 has information on the distance between the parts having a low radiation transmittance obtained from the coordinate body 15. This information is read by information reading means (detector 20), and the distance is calculated by interval determining means (image memory device 27, calculator 25, and memory device 26) based on the read information. In the interval determination means, the calculated value is compared with a preset reference interval value, and it is determined whether or not the radiation irradiation position is moving at a rotation angle, a moving amount, a moving speed, or the like as planned. If the result of this determination is that the radiation irradiation position is a movement that deviates from the plan, a control signal is output from the interval determination means to the irradiation control means (interlock control circuit 23). Based on this control signal, the irradiation control means stops, for example, the irradiation of radiation, thereby ensuring patient safety.

Embodiment 4 FIG. 11 shows the structure of a coordinate body of a three-dimensional concentrating radiation therapy apparatus according to the present invention.

In the fourth embodiment, the coordinate body 15 has a cylindrical shape, and the basic outer shape is the same as that of the first embodiment. The coordinate body 15 includes a portion 15A having a high radiation transmittance and a code area 15E. The code regions 15E are regularly arranged at predetermined intervals along the moving direction of the radiation irradiation position. As shown in FIG. 12, the code regions 15E include a code 15e1 having a low radiation transmittance (for example, a shielding material) and a code 15e2 having a high radiation transmittance. Composed of combinations. That is, the code 15e1 constitutes the encoded information 0 (or information 1), and the code 15e2 constitutes the encoded information 1
(Or information 0). Therefore, although not limited to this information amount, in the present embodiment, since a total of nine codes 15e1 and 15e2 are arranged in the code region 15E, the code region 15E has an information amount of 2 9. Movement information such as rotation angle information, movement amount information, movement speed information, and the like are individually written in the plurality of arranged code areas 15E.

The detector 20 of the radiation detecting section 16 is constituted by a sensor capable of simultaneously recognizing the coded movement information of the code 15e1 and the code 15e2 of the code area 15E. For example, a matrix sensor is used.

The detector 20 is connected to an image memory device 27 as shown in FIG. 13, and this image memory device 27 is connected to an interlock control circuit 23 through a computer 25. The image memory device 27 stores the movement information (encoded movement information of the codes 15e1 and 15e2 of the code area 15E) read by the detector 20 as image information in real time (or at predetermined time intervals). The memory device 26 is connected to the computer 25. Memory device 26
In advance, information such as a movement amount corresponding to the movement information written in the code area 15E and reference movement information such as a movement amount for each predetermined treatment time based on the radiation treatment plan are stored in advance. In the computer 25, the image memory device 2
7, the decoding movement information corresponding to the code area 15E is read from the memory device 26 based on the image information stored in the memory device 7, and the read decoding movement information is compared with the reference movement information read from the memory device 26. I do. When a deviation occurs between the two information, the computer 25 outputs a control signal to the interlock control circuit 23, and the radiation dose is controlled by the interlock control circuit 23.

The operation procedure of the three-dimensional focusing radiotherapy apparatus of this embodiment is the same as that of the first embodiment, and the method of controlling the radiation dose is described in the configuration. Omitted.

In the three-dimensional condensing type radiotherapy apparatus configured as described above, the radiation to be irradiated is formed by combining both the part (code 15e1) having a low radiation transmittance and the part (code 15e2) having a high radiation transmittance. A code area 15E having encoded movement information such as a rotation angle, a movement amount, and a movement speed passes through the coordinate body 15 regularly arranged along the movement direction of the radiation irradiation position. This coordinate body 15
Has the encoded movement information of the code area 15E of the coordinate body 15. The encoded movement information is read by the information reading means (detector 20), and the read encoded movement information is decoded by the decoding determination means (image memory device 2).
7, the computer 25 and the memory device 26) generate decoded movement information that can be compared with the reference movement information. The generated decoded movement information is compared with the reference movement information by the decoding determination means, and it is determined whether or not the radiation irradiation position is moving based on the rotation angle, the moving amount, the moving speed, etc. according to the radiation treatment plan. . When the radiation irradiation position is a movement that deviates from the plan, a control signal is output from the decoding determination unit to the irradiation control unit.

The present invention is not limited to the above embodiment, but can be variously modified without departing from the scope of the invention.

For example, the present invention can be applied to a radiation therapy apparatus that uses radiation other than X-rays such as γ-rays.

[0056]

As described above, according to the present invention,
It is possible to provide a radiation therapy apparatus capable of detecting a radiation irradiation position during radiation irradiation and appropriately controlling the radiation irradiation when a moving route, a moving speed, and the like of the radiation irradiation position deviate from a preset plan.

[Brief description of the drawings]

FIG. 1 is a schematic structural diagram of a linac of a three-dimensional concentrating radiation therapy apparatus according to Embodiment 1 of the present invention.

FIG. 2 is a block diagram of a radiation control system of the three-dimensional concentrating radiation therapy apparatus.

FIG. 3A is a cross-sectional view of a coordinate body of the three-dimensional converging radiation therapy apparatus, and FIG. 3B is a front view of the coordinate body.

FIG. 4 is a perspective view of the coordinate body.

FIGS. 5A and 5B are projection views of radiation transmitted through the coordinate body.

FIG. 6 is a perspective view of a coordinate body according to a second embodiment of the present invention.

FIG. 7 is a block diagram of a radiation control system according to the second embodiment.

FIG. 8 is a perspective view of a coordinate body according to a third embodiment of the present invention.

FIG. 9 is a block diagram of a radiation control system according to the third embodiment.

FIG. 10 is a projection view of radiation transmitted through the coordinate body.

FIG. 11 is a perspective view of a coordinate body according to a fourth embodiment of the present invention.

FIG. 12 is a projection view of radiation transmitted through the coordinate body.

FIG. 13 is a block diagram of a radiation control system according to the fourth embodiment.

FIG. 14 is a schematic structural view of a linac of a conventional three-dimensional concentrating radiation therapy apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Radiation irradiation part 4 Power supply part 5 X-ray applicator 15 Coordinate body 15A High part 15B, 15C, 15D Low part 15E Code area 16 Radiation detection part 20 Detector 21 Threshold setting circuit 22 Comparator 23 Interlock control circuit 24 Counter 25 Computer 26 Memory device 27 Image memory device

Claims (6)

(57) [Claims] 1. A radiotherapy apparatus capable of irradiating radiation toward the rotation center while moving with respect to the rotation center, wherein the radiation treatment apparatus is disposed in the radiation irradiation path near the rotation center and has a high radiation transmittance. And a coordinate body having a reference movement path of a radiation irradiation position formed by the high or low part of the radiation transmittance, and a reference movement path of the coordinate body from radiation transmitted through the coordinate body. Position reading means for reading the information of the irradiation position and the actual movement path of the irradiation position; and whether the irradiation position is moving along the reference movement path based on the information read by the irradiation position reading means. And an irradiation control unit that controls a radiation dose based on an output signal of the irradiation position judgment unit. Radiation therapy device that. 2. The radiation therapy apparatus according to claim 1, wherein the coordinate body partially surrounds the rotation center and passes through the rotation center without transmitting radiation before passing through the rotation center. A radiotherapy apparatus characterized by being configured in a cylindrical shape that allows transmission of later radiation. 3. The radiation treatment apparatus according to claim 1, wherein a portion of the coordinate body having a low radiation transmittance is formed of a linear shielding material, and the shielding material is irradiated with the radiation. A radiotherapy apparatus characterized by forming a reference movement path of a position. 4. A radiotherapy apparatus capable of irradiating radiation toward the rotation center while moving with respect to the rotation center, wherein the portion is disposed in the radiation irradiation path near the rotation center and has a high radiation transmittance. And a coordinate body having a low portion, and a plurality or portions where the radiation transmittance is high or low alternately and regularly arranged in the moving direction of the radiation irradiation position; and Information reading means for reading information of a portion where the radiation transmittance is high or low, a counting means for counting information read by the information reading means, and a count value counted by the counting means being preset. Count value judging means for judging whether or not there is a difference between the two count values, and an output signal of the count value judging means. Radiation therapy apparatus comprising: the illumination control means for controlling the radiation dose, the basis of the. 5. A radiation therapy apparatus capable of irradiating radiation toward the rotation center while moving with respect to the rotation center, wherein the radiation therapy apparatus is disposed in the irradiation path of the radiation in the vicinity of the rotation center and has a plurality of radiation transmittances. A coordinate body having a high portion and a low portion, and wherein the distance between the high and low parts of the radiation transmittance is changed along the moving direction of the radiation irradiation position; and An information reading unit that reads information on the distance between the high and low parts of the radiation body of the coordinate body, and the distance is calculated based on the information read by the information reading unit; Interval determining means for determining whether there is a difference from the reference interval value, and irradiation control means for controlling a radiation dose based on an output signal of the interval determining means. Radiation therapy apparatus characterized by a. 6. A radiotherapy apparatus capable of irradiating radiation toward the rotation center while moving with respect to the rotation center, wherein the portion is disposed in the radiation irradiation path near the rotation center and has a high radiation transmittance. In, a coordinate body formed in a low portion or a combination of both, and a code area having coded moving information such as a moving amount, a moving speed, and the like are regularly arranged along the moving direction of the radiation irradiation position, Information reading means for reading the encoded movement information of the code area of the coordinate body from the radiation transmitted through the coordinate body, and generating decoded movement information that can be compared and determined from the encoded movement information read by the information reading means, Decoding determination means for comparing the generated decoded movement information with predetermined reference movement information to determine whether or not there is a difference between the two pieces of information; Radiation therapy apparatus comprising: the illumination control means for controlling the radiation dose, a based on the control signal outputted from the stage.