WO2016113906A1 - Radiation irradiation apparatus - Google Patents

Abstract

For the purpose of making it possible to switch between an operation mode using a flattening filter in which a radiation dose distribution is even and a flattening filter-free operation mode and for the purpose of miniaturizing the apparatus, the present invention comprises a radiation source (21) and a filter (30) that attenuates the radiation irradiated from the radiation source, wherein the filter comprises: on an interior thereof, a container (31) capable of housing a liquid that attenuates the radiation; and switching means (32A), (33A) that make it possible to place and remove the liquid inside the container.

Description

Radiation irradiation equipment

The present invention relates to a radiation irradiation apparatus.

One method of treating cancer is radiation therapy. In radiation therapy, therapeutic radiation (electron beam, X-ray, proton beam, heavy particle beam, gamma ray, neutron beam, etc.) is irradiated so as to concentrate on the affected area, while suppressing the side effects of radiation on normal cells. Treatment is performed by irradiating only cancer cells with a lethal dose of radiation.

In a general X-ray radiotherapy apparatus, X-rays are generated by accelerating electrons with an electron beam accelerator (linac) and colliding the accelerated electron beam with an X-ray target. The generated X-ray is defined as a therapeutic X-ray having a predetermined irradiation field size by limiting the irradiation field with a collimator.
In general, the air dose distribution of the therapeutic X-ray is required to be uniform (flat) in the irradiation field.

However, X-rays generated when an electron beam collides with an X-ray target has directivity in the forward direction with respect to the electron beam acceleration direction, and the dose in the center of the irradiation field becomes high. Therefore, a method has been used for a long time to flatten the air dose distribution by installing a conical metal part called a flattening filter behind the X-ray target and attenuating the X-ray according to the path length through which the flattening filter passes. ing.

On the other hand, since the dose of X-rays generated from the target is attenuated by flattening the air dose distribution by the flattening filter, the output of the linac is wasted. Therefore, in the case of therapeutic applications that do not require a flat dose distribution in the irradiation field, the device configuration without a flattening filter is used to shorten the treatment time and increase the medical dose due to the high dose rate. There are cases in which it is aimed for a therapeutic effect. Such an operation mode is called flattening filter free.
Even when the flattening filter is free, a configuration is known in which the same electron beam accelerator is used instead of a different device, and the operation can be performed by switching whether or not the flattening filter is installed.

Moreover, as a radiotherapy apparatus, the electron beam treatment which irradiates a patient with an electron beam without converting into an X-ray is also performed. Also in this case, in order to improve the air dose distribution of the electron beam, a substance called a scattering foil is arranged, and the patient is irradiated after scattering the electron beam.
There is known a device that switches operation modes in the same device by mechanically moving a substrate on which a plurality of flattening filters or scattering foils are installed.

U.S. Pat. No. 8,761,347 B2

However, in radiation therapy, for example, a radiation irradiation device that goes around the affected part around the affected part with a travel drive device irradiates the affected part from various directions toward the affected part. In order to circulate around, there is a problem that the apparatus becomes large. Furthermore, when the apparatus size is increased, there is a problem that the deviation of the dose reproducibility due to the deviation of the positioning reproducibility due to the mechanical drive may affect the quality assurance of the irradiation performance.

The present invention has been made in view of the above circumstances, and intends to achieve the following object.
1. It is possible to switch between using a flattening filter with a flat dose distribution as an operation mode and flattening filter free.
2. To reduce the size of the device.
3. To improve positioning reproducibility by machine drive.

The radiation irradiation apparatus of the present invention comprises a radiation source,
A filter for attenuating radiation emitted from the radiation source,
A container capable of containing a liquid that attenuates radiation therein;
The above-mentioned problem has been solved by providing switching means capable of taking liquid into and out of the container.
In the radiation irradiation apparatus of the present invention, it is preferable that the container is formed in a weight shape having the radiation source side as a vertex.
In the radiation irradiation apparatus of the present invention, the switching unit may include a liquid supply unit that supplies and discharges liquid into the container, and a gas discharge unit that discharges and supplies gas into the container. .
In the radiation irradiation apparatus of the present invention, it is preferable that the container has a plurality of rooms partitioned inside, and the switching means can allow liquid to be taken in and out of each room.
In the radiation irradiation apparatus of the present invention, the plurality of rooms may be concentrically partitioned around a radiation irradiation axis inside the container.
In the present invention, a collimator may be provided around the radiation irradiation axis of the filter, and a pipe in the switching unit may penetrate the collimator, and the pipe may be bent in the collimator.

The radiation irradiation apparatus of the present invention includes a radiation source and a filter for attenuating radiation emitted from the radiation source, and the filter contains a container capable of containing a liquid for attenuating radiation inside the container. With a switching means that allows liquid to be taken in and out, it is possible to switch the presence or absence of a flattening filter by filling and discharging the liquid in the container, and flattening filter free by simply taking in and out the liquid Can be provided.

In the radiation irradiation apparatus of the present invention, the container is formed in a weight shape with the radiation source side as the apex, so that the radiation passes through the liquid thickness along the container shape by the liquid filled in the container. Therefore, the X-rays generated by the collision of the electron beam with the X-ray target have directivity in the forward direction with respect to the electron beam acceleration direction, and the flattening in which the dose at the center of the irradiation field is increased is made uniform. It can exhibit a function as a filter. Here, the liquid with which the container is filled can be a substance that has an ability to attenuate radiation to be irradiated, such as mercury or water.

In the radiation irradiation apparatus of the present invention, the switching unit includes a liquid supply unit that supplies and discharges liquid into the container, and a gas discharge unit that discharges and supplies gas into the container. The liquid supply means supplies the liquid into the container, and the gas discharge means discharges the gas into the container so that the container is filled with the liquid and functions as a flattening filter. By discharging the liquid from the inside and supplying the gas into the container by the gas discharging means, the liquid can be discharged from the container and switched to a flattening filter-free state.

In the radiation irradiation apparatus of the present invention, the container has a plurality of rooms partitioned inside, and the switching means can allow liquid to be taken in and out of each room, thereby switching the presence or absence of liquid in the plurality of rooms. Since the liquid passage distance in the radiation irradiation direction can be selected and switched from a plurality of states, the function is equivalent to that provided with a large number of conical flattening filters as described in Patent Document 1. It is possible to have

In the radiation irradiation apparatus of the present invention, a plurality of flattening filters made of conical solids having different heights are provided by concentrically partitioning the plurality of chambers around the radiation irradiation axis inside the container. It is possible to switch whether or not the radiation is attenuated from the central portion of the radiation irradiation axis to the periphery of the irradiation field concentrically.

According to the present invention, a collimator is provided around the radiation irradiation axis of the filter, and the pipe in the switching unit penetrates the collimator, and the pipe is bent in the collimator, whereby radiation propagates in the pipe. It is possible to prevent leakage to the outside of the collimator, and to achieve both a radiation shielding function as a collimator and a function of supplying / discharging liquid or gas to / from the flattening filter container.

According to the present invention, it is possible to switch between using a flattening filter having a flat dose distribution as an operation mode and flattening filter-free, reducing the size of the apparatus, and improving positioning reproducibility by mechanical drive. It is possible to achieve the effect of being able to.

It is a perspective view which shows 1st Embodiment of the radiotherapy apparatus which has a radiation irradiation apparatus which concerns on this invention. It is a front sectional view showing the vicinity of the flattening filter in the first embodiment of the radiation irradiation apparatus according to the present invention. It is a graph explaining equalization of the flattening filter in 1st Embodiment of the radiation irradiation apparatus concerning the present invention. It is a schematic front sectional view showing a flattening filter in the first embodiment of the radiation irradiation apparatus according to the present invention. It is an enlarged view which shows the flattening filter and collimator in 1st Embodiment of the radiation irradiation apparatus which concerns on this invention. It is a front sectional view showing another example of the flattening filter in the first embodiment of the radiation irradiation apparatus according to the present invention. It is a model front sectional view which shows the other example of the flattening filter in 2nd Embodiment of the radiation irradiation apparatus which concerns on this invention. It is a model front sectional view which shows the flattening filter in 3rd Embodiment of the radiation irradiation apparatus which concerns on this invention. It is a model front sectional view which shows the other example of the flattening filter in 4th Embodiment of the radiation irradiation apparatus which concerns on this invention. It is a model regular cross section which shows the other example of the flattening filter in 5th Embodiment of the radiation irradiation apparatus which concerns on this invention. It is a model front sectional view which shows the other example of the flattening filter in 6th Embodiment of the radiation irradiation apparatus which concerns on this invention.

Hereinafter, a first embodiment of a radiation irradiation apparatus according to the present invention will be described with reference to the drawings.
FIG. 1 is a perspective view showing a radiotherapy apparatus having a radiation irradiation apparatus in the present embodiment, FIG. 2 is a front sectional view showing the vicinity of a flattening filter in the present embodiment, and FIG. FIG. 1 is a schematic front sectional view showing a flattening filter in FIG. 1. In the figure, reference numeral 1 denotes a radiation therapy system.

As shown in FIG. 1, a radiation therapy apparatus 1 having a radiation irradiation apparatus according to the present embodiment includes a turning drive device 11, an O-ring 12, a traveling gantry 13, and a swing mechanism (Gimbal mechanism) 14. And 10 A of irradiation parts, sensor arrays 15a, 15b, and 15c, and the couch 16 are comprised. The irradiation unit 10 </ b> A includes a radiation irradiation device 20, a multi-leaf collimator (MLC) 17, imaging radiation sources 18 a and 18 b, and an infrared (IR) camera 19.

As shown in FIG. 1, the turning drive device 11 supports an O-ring 12 on a base so as to be rotatable about a rotation axis A11, and rotates the O-ring 12 according to control of a radiotherapy device control device (not shown). The rotation axis A11 is a vertical axis.
As shown in FIG. 1, the O-ring 12 is formed in a ring shape centered on the rotation axis A12, and supports the traveling gantry 13 so as to be rotatable about the rotation axis A12. The rotation axis A <b> 12 is an axis in the longitudinal direction of the couch 16. The rotation axis A12 is a horizontal axis (that is, an axis perpendicular to the vertical direction), and is orthogonal to the rotation axis A11 at the isocenter P11. The rotation axis A12 is fixed with respect to the O-ring 12. That is, the rotation axis A12 rotates around the rotation axis A11 as the O-ring 312 rotates.

As shown in FIG. 1, the traveling gantry 13 is formed in a ring shape centered on the rotation axis A <b> 12, and is disposed inside the O ring 12 so as to be concentric with the O ring 12. The radiotherapy apparatus 1 further includes a travel drive device (not shown), and the travel gantry 13 rotates about the rotation axis A12 with power from a travel drive device (not shown). When the traveling gantry 13 rotates, the traveling gantry 13 integrally rotates components such as the imaging radiation source 18a and the sensor array 15b, the imaging radiation source 18b, and the sensor array 15c.

As shown in FIG. 1, the swing mechanism 14 is fixed to the inside of the ring of the traveling gantry 13 and supports the irradiation unit 10 </ b> A on the traveling gantry 13. The head swing mechanism 14 supports the irradiation unit 10A so that the direction of the irradiation unit 10A can be changed, and changes the direction of the irradiation unit 10A according to control of a radiotherapy apparatus control device (not shown). Specifically, the swing mechanism 14 rotates the irradiation unit 10A around a pan axis A21 parallel to the rotation axis A12. The swing mechanism 14 rotates the irradiation unit 10A around a tilt axis A22 orthogonal to the pan axis A21.

As shown in FIG. 1, the irradiation unit 10 </ b> A is disposed inside the traveling gantry 13 and supported by the swing mechanism 14, and irradiates therapeutic radiation and imaging radiation.
As shown in FIG. 1, the multi-leaf collimator 17 shields part or all of the therapeutic radiation B11 by opening and closing the leaf according to the control of the radiation therapy apparatus control device. Thereby, the multi-leaf collimator 17 adjusts the shape of the irradiation field when the therapeutic radiation B11 is irradiated to the patient T11.

As shown in FIG. 1, the imaging radiation source 18a irradiates imaging radiation (X-rays) toward the sensor array 15b in accordance with the control of the radiation therapy apparatus control device. The imaging radiation source 18b irradiates imaging radiation toward the sensor array 15c under the control of the radiation therapy apparatus control device. The imaging radiation sources 18a and 18b are fixed to the irradiation unit 10A (for example, the housing of the multi-leaf collimator 17) in a direction in which the irradiated radiation is orthogonal.

As shown in FIG. 1, the sensor array 15 a is arranged at a position where the therapeutic radiation from the radiation irradiation device 20 strikes and faces the radiation irradiation device 20, and is fixed inside the ring of the traveling gantry 13. Yes. The sensor array 15a receives the therapeutic radiation transmitted through the patient T11 and the like for confirmation of the irradiation position and recording of treatment. In addition, light reception here is receiving radiation.

As shown in FIG. 1, the sensor array 15 b is disposed at a position where the imaging radiation from the imaging radiation source 18 a strikes and faces the imaging radiation source 18 a, and is fixed inside the ring of the traveling gantry 13. Has been. The sensor array 15b receives imaging radiation irradiated from the imaging radiation source 18a and transmitted through the patient T11 and the like for specifying the affected part position.
The sensor array 15 c is arranged at a position where the imaging radiation from the imaging radiation source 18 b is hit, facing the imaging radiation source 18 b, and is fixed inside the ring of the traveling gantry 13. The sensor array 15c receives the imaging radiation irradiated from the imaging radiation source 18b and transmitted through the patient T11 and the like for specifying the affected part position.

The sensor arrays 15a and 15b receive imaging radiation from the imaging radiation sources 18a and 18b, whereby a radiation image is obtained.

As shown in FIG. 1, the couch 16 is used for the patient T11 to lie down and supports the patient T11. The couch 16 is installed such that the longitudinal direction thereof faces the direction of the rotation axis A12. The couch 16 can be moved in various directions with the longitudinal direction thereof directed toward the rotation axis A12.

The infrared (IR) camera 19 receives infrared rays and takes an infrared image. In particular, the infrared camera 19 is installed toward a patient T11 lying on the couch 16, as shown in FIG. And the infrared camera 19 images the infrared marker provided in the body surface near the affected part of patient T11, and acquires the positional information on the said infrared marker in real time. In particular, the infrared camera 19 acquires position information of the infrared marker at the time in association with the time information.

The radiation irradiation apparatus 20 irradiates therapeutic radiation toward the affected part of the patient T11 in accordance with control of a radiotherapy apparatus control apparatus (not shown).
As shown in FIG. 1, since the radiation irradiation apparatus 20 is supported by the traveling gantry 13 via the swing mechanism 14, the radiation irradiation apparatus 20 is once directed to the isocenter P11 by adjusting the swing mechanism 14. Even if the O-ring 12 is rotated by the turning drive device 11 or the traveling gantry 13 is rotated by the traveling drive device, the therapeutic radiation B11 always passes through the isocenter P11. Therefore, the radiation irradiation apparatus 20 can irradiate the therapeutic radiation B11 from various directions toward the isocenter P11 by rotating around the rotation axis A11 or the rotation axis A12.

As shown in FIG. 2, the radiation irradiation apparatus 20 includes an electron beam accelerator 21, an X-ray target (target) 22, a flattening filter 30, and a collimator 24 as a radiation source.

The electron beam accelerator 21 has a vacuum window in which an electron beam from an electron beam generation source (not shown) is changed in direction by a bending magnet and allows the electron beam to pass while maintaining a vacuum. Is converted to X-rays.
At the irradiation direction position of the electron beam accelerator 21, there are a collimator 24 for narrowing down the electron beam and the X-ray from the target 22, and a flattening filter 30 for making the dose distribution of the electron beam and the X-ray uniform on the irradiation surface. Be placed.

As shown in FIG. 4, the flattening filter 30 includes a conical hollow container 31 having the radiation source side at the top, a thin pipe 32 for injecting liquid into the container, and a thin pipe 33 for injecting gas. Have.
A liquid supply source 34 capable of supplying and discharging a liquid that attenuates radiation is connected to the pipe 32, and these constitute a liquid supply means 32A. The liquid supply source 34 has pressurizing means such as a pump (not shown), and is capable of pressurizing and discharging liquid. As the liquid filled in the liquid supply source 34, mercury, oil, water or the like can be applied.
The pipe 33 is connected with a gas discharge source 35 capable of discharging and supplying an internal gas when supplying liquid to the container 31, and constitutes a gas discharge means 33 </ b> A. The gas supply source 35 has pressurizing means such as a pump (not shown) and is capable of pressurizing and discharging gas. As the gas discharged to the gas discharge source 35, air or atmospheric pressure gas such as nitrogen is applicable.

As shown in FIGS. 5 and 4, the pipe 33 penetrates the inside of the collimator 24 and has a bent portion 33 k inside the collimator 24, so that radiation is not irradiated to the outside of the collimator 24 through the pipe 33. It is like that. When the pipe 32 passes through the collimator 24, a similar bent portion 32k can be provided. Note that the bent portion 33k only needs to be formed in the contents by irradiating the outside of the collimator 24 with radiation through the inside of the tube, and is preferably bent at least once, preferably twice or more. In addition, the pipe 33 has a pipe diameter set so that radiation is shielded in the vicinity of the bent portion 33 k inside the collimator 24. At the same time, the pipe diameter of the pipe 32 is also selected as the content that hinders the supply and discharge of gas and liquid.

The container 31 and the collimator 24 are disposed at a position that is coaxial with the axis of the electron beam emitted from the electron beam accelerator 21.
A pipe 32 of liquid supply means 32A is connected to the container 31 at the bottom 31a side, and a pipe 33 of gas supply means 33A is connected to the top 31b side.

The shape of the container 31 is such that the liquid height is set so that the air dose distribution is flattened by the X-ray shielding of the filled liquid when irradiation is performed with the liquid filled. Further, the height of the container 31 is set high at the irradiation center, and the height of the container 31 is set low toward the periphery. Therefore, when the air dose distribution in the container 31 not filled with the liquid is in the state shown in FIG. 3A, the air dose distribution in the container 31 filled with the liquid is shown in FIG. It will be in the state flattened.

The liquid supply means 32A and the gas supply means 33A constitute switching means for switching the mode of the flattening filter, and control the amount of liquid supplied into the container 31 and the amount of gas discharged from the container 31 in conjunction with each other. It is possible. At the same time, the amount of liquid discharged from the container 31 and the amount of gas supplied to the container 31 can be controlled in conjunction with each other.
As shown in FIG. 4, the piping 32 and the piping 33 are provided with scales 32d and 33d, respectively, and this portion is a transparent piping so that the liquid located inside thereof can be visually recognized.

When X-rays are used as a treatment line bundle in the radiation irradiation apparatus 20 of the present embodiment, liquid is applied to the flattening filter 30 positioned at the irradiation position so as to match the energy of the X-rays converted by the target 22. While supplying the liquid to the container 31 from the supply means 32A, the gas in the container 31 is discharged to the gas discharge means 33A. As a result, the gas is discharged from the gas discharge side pipe 33 and, at the same time, the liquid is filled into the container 31 of the flattening filter 30 from the liquid injection side pipe 32.

By this operation, irradiation is performed in a state where the container 31 of the flattening filter 30 is filled with the liquid, so that the filled liquid shields X-rays, so that the flattening filter 30 corresponding to the X-ray to be used is obtained. It becomes effective, the air dose distribution is flattened, and it becomes possible to obtain a treatment bundle of X-rays with a uniform dose distribution.

In addition, when X-rays are used as the therapeutic radiation bundle in the radiation irradiation apparatus 20 of the present embodiment, the flattening filter 30 located at the irradiation position is matched with the energy of the X-rays converted by the target 22. Then, gas is supplied from the gas discharge means 33A to the container 31, and the liquid in the container 31 is discharged to the liquid supply means 32A. Thereby, the gas is filled into the container 31 of the flattening filter 30 from the gas supply side pipe 33, and at the same time, the liquid is discharged from the liquid discharge side pipe 32.

By this operation, irradiation is performed in the flattening filter free mode by performing irradiation with the liquid in the container 31 of the flattening filter 30 being emptied. In this case, the dose rate can be improved even with the same accelerator output.

When the gas is supplied to the container 31 in the flattening filter 30, the flattening filter is in a state in which the irradiation dose is higher than that in the case where the same accelerator output is made uniform without uniformizing the air dose. Irradiation in free mode can be made possible. At the same time, the container 31 itself of the flattening filter 30 serves as a filter plate, and the absorbed dose to the patient's skin can be reduced by removing the low energy X-ray component.

In the radiation irradiation apparatus 20 of this embodiment, since the flattening filter free mode and the flattening state of the air dose by the flattening filter 30 can be switched only by taking in and out of the liquid, a plurality of flattening filters are provided in advance. In addition, since the means for switching between them is not required, the radiation irradiation apparatus 20 can be miniaturized, and the radiation irradiation apparatus 20 can be adapted to an apparatus in which the radiation irradiation apparatus 20 turns around the patient P11 to be irradiated like the radiation treatment apparatus 1. Therefore, the positioning reproducibility by mechanical drive can be improved.

In the radiation irradiation apparatus 20 according to the present embodiment, the position of the liquid while visually confirming the boundary position between the liquid and the gas from the outside of the pipe 33 in the vicinity of the scales 32d and 33d provided on the pipes 32 and 33 that are transparent pipes. By appropriately adjusting, the presence / absence of liquid inside the container 31 can be confirmed, and the mode of the flattening filter 30 can be confirmed.
Further, by providing the pipes 32 and 33 with the bent portions 32k and 33k within the collimator 24 and setting the pipe diameter, radiation leakage from the pipes 33 and 32 can be reduced inside the collimator 24.

In the present embodiment, the pipe 33 of the gas discharge means 33A is arranged so as to be connected to the top portion 31b side of the container 31, but instead of this, as shown in FIG. An inner inclined surface 33g parallel to the side surface portion 31c is provided inside 31c, and a space parallel to the side surface portion 31c is formed by the inner inclined surface 33g, and a space inside the side surface portion 31c is formed outside the inner inclined surface 33g. The container 31 is divided by the entire length in the height direction, and an opening 33f is provided at the top position of the inner slope 33g, so that the pipe 33 can be connected to the bottom 31a that is outside the inner slope 33g.

Thereby, the outer space of the inner slope 33g becomes an extension of the pipe 33, and it is possible to reduce the influence of radiation irradiated by the pipe 33. In particular, since the top 31b of the container 31 is the portion with the strongest radiation dose, it is preferable that the influence on the dose distribution is reduced by not having the pipe 33 positioned in this portion. At the same time, since the opening 33f is located at the top of the inner slope 33g, it is possible to suitably discharge the gas from the inside of the container 31 through the opening 33f, and reliably discharge the gas in the inner space of the inner slope 33g. It becomes easy to fill the liquid, and it becomes possible to reliably shield the dose set in the initial stage. At the same time, the pipe 33 can be arranged without penetrating the collimator 24.

Hereinafter, 2nd Embodiment of the radiation irradiation apparatus 20 which concerns on this invention is described based on drawing.
FIG. 7 is a schematic diagram showing the flattening filter 30 in the present embodiment.
The present embodiment is different from the first embodiment described above in respect of the liquid supply means 32A and the gas discharge means 33A, and other corresponding components are denoted by the same reference numerals and description thereof is omitted. .

In the present embodiment, as shown in FIG. 7, in the liquid supply means 32A, a pipe 32a and a pipe 32b are connected to the container 31, and the pipe 32a and the pipe 32b are connected to valves 34a and 334b and a pump. It is connected to the liquid supply source 34 via 34d. A pipe 32a on the liquid discharge side is connected near the bottom 31a of the container 31, and a pipe 32b on the liquid supply side is connected on the top 31b side of the container 31.

In the liquid supply means 32A, when supplying the liquid, the valves 34a and 34b are opened, and the pump 34d is operated to supply the liquid from the pipe 32b. When discharging the liquid, the valves 34a and 34b are opened. The liquid is discharged from the pipe 32a by operating the pump 34d.

In the gas discharge means 33A, a pipe 33a and a pipe 33b are connected to the container 31, and the pipe 33a and the pipe 33b are connected to a gas discharge source 35 through valves 35a and 35b and a pump 35d. . A pipe 33a on the gas discharge side is connected to the vicinity of the top 31b of the container 31, and a pipe 33b on the gas supply side is connected to the lower part 31a side of the container 31.

In the gas discharge means 33A, the valves 35a and 35b are opened when the gas is supplied, and the pump 35d is operated to supply the gas from the pipe 33b, and the valves 35a and 35b are opened when the gas is discharged. By operating the pump 35d, the liquid is discharged from the pipe 33a.

Similarly to the first embodiment, the liquid supply means 32A and the gas discharge means 33A perform the supply of the liquid to the container 31 and the discharge of the gas in conjunction with the first embodiment, and the discharge of the liquid from the container 31 and the supply of the gas. It is supposed to be done.

In the radiation irradiation apparatus 20 of the present embodiment, it is possible to achieve the same effects as those of the first embodiment described above, and it is possible to easily supply and discharge liquid and gas to and from the container 31. It becomes. Further, by appropriately switching the valves 34a, 34b, 35a, 35b, as shown in FIG. 1, the radiation irradiation device 20 rotates around the patient P11 to be irradiated, and the top 31b of the container 31 is moved from the bottom 31a. However, even when the liquid is located on the lower side, it is possible to easily switch between the liquid filling uniform mode and the flattening filter free mode by filling and discharging the liquid and gas without any trouble.

Hereinafter, 3rd Embodiment of the radiation irradiation apparatus 20 which concerns on this invention is described based on drawing.
FIG. 8 is a schematic diagram showing the flattening filter 30 of the radiation irradiation apparatus 20 in the present embodiment.
This embodiment is different from the first and second embodiments described above with respect to the container 31, and other corresponding components are denoted by the same reference numerals and description thereof is omitted.

In the present embodiment, the interior of the container 31 is configured to have a room divided into a plurality of sections. Specifically, as shown in FIG. 8, the side surface forming the outer slope of the container 31 in the container 31. An inner side surface portion 31f is erected over the entire height of the container 31 inside the portion 31c.
The inner side surface portion 31f has a conical shape and forms an inner room 31A together with the central portion of the bottom portion 31a, and the inner side surface portion 31f forms a space serving as an outer room 31B with the side surface portion 31c.

In the inner room 31A, the pipe 32a is connected to the bottom 31a which is the inner side of the inner side surface part 31f, and the pipe 33a is connected to the top part 31b side of the inner side surface part 31f. The pipe 32a is connected to the liquid supply source 34 via the valve 34a as the liquid supply means 32A, and the pipe 33a is connected to the gas discharge source 35 via the valve 35a as the gas discharge means 33A to the inner room 31A. Liquid supply / gas discharge and liquid discharge / gas supply are possible.

In the outer room 31B, a pipe 32b is connected to the bottom 31a that is outside the inner side surface 31f, and a pipe 33b is connected to the top 31b side of the side 31c that is outside the inner side 31f. The pipe 32b is connected to the liquid supply source 34 via the valve 34b as the liquid supply means 32A, and the pipe 33b is connected to the gas discharge source 35 via the valve 35b as the gas discharge means 33A to the outer room 31B. Liquid supply / gas discharge and liquid discharge / gas supply are possible.

By operating the liquid supply means 32A and the gas discharge means 33A with the valve 34a and the valve 35a opened, the liquid supply / gas discharge and liquid discharge to the inner room 31A in the inner room 31A that is the inner space of the inner side surface portion 31f.・ Gas supply is possible.
Further, by operating the liquid supply means 32A and the gas discharge means 33A with the valve 34b and the valve 35b open, in the outer room 31B that is the outer space of the inner side surface portion 31f, the liquid supply / gas discharge to the outer room 31B and Liquid discharge and gas supply are possible.

Thus, the outer room 31B, which is the outer space of the inner side surface portion 31f, is not filled with liquid, and the inner room 31A, which is the inner space of the inner side surface portion 31f, is not filled with liquid without reducing the amount of radiation in this portion. And the radiation dose can be reduced only in this portion.
Thereby, flattening corresponding to the electron beam to be used can be achieved without providing flatness filters made of a plurality of differently shaped solids.

The radiation irradiation apparatus 20 of the present embodiment can achieve the same effects as those of the first and second embodiments described above, and further, only the inner room 31A of the container 31 and the inner room 31A and the outer By supplying and discharging liquid and gas to and from the room 31B, the flattened state can be easily switched.
In addition, by switching the valves 34a, 34b, 35a, and 35b as appropriate to operate the liquid supply means 32A and the gas discharge means 33A, the maximum uniformization mode in which the liquid is filled in the inner room 31A and the outer room 31B, and only the inner room 31A. It is possible to easily switch between the small uniform mode in which the liquid is filled and the flattening filter free mode in which the liquid is not filled.

Hereinafter, 4th Embodiment of the radiation irradiation apparatus 20 which concerns on this invention is described based on drawing.
FIG. 9 is a schematic diagram showing the flattening filter 30 of the radiation irradiation apparatus 20 in the present embodiment.
This embodiment is different from the above-described third embodiment in the point relating to the pipe 33, and the corresponding constituent elements other than this are denoted by the same reference numerals and description thereof is omitted.

In the present embodiment, as shown in FIG. 9, an inner pipe 33m is provided inside the inner room 31A, and an inner pipe 33n is provided inside the outer room 31B.
The inner pipe 33m extends to the vicinity of the top part 31b along the inner side of the inner side surface part 31f, and is connected to the pipe 33a provided on the bottom part 31a which is the inner side of the inner side part 31f.
The inner pipe 33n extends along the inner side of the side part 31c to the vicinity of the top part 31b, and is connected to a pipe 33b provided on the bottom part 31a that is outside the inner side part 31f and inside the side part 31c.

In the radiation irradiation apparatus 20 of the present embodiment, the same effects as those of the third embodiment described above can be obtained, and the end openings of the inner pipes 33m and 33n are near the tops of the inner side surface portion 31f and the side surface portion 31c. Therefore, it is possible to suitably discharge gas from the inner room 31A and the outer room 31B from the inner pipes 33m and 33n, and reliably discharge gas in each of the inner room 31A and the outer room 31B. In addition, it becomes easy to fill the liquid, and it becomes possible to reliably shield the dose set in the initial stage. At the same time, the pipe 33 can be arranged without penetrating the collimator 24.

Hereinafter, 5th Embodiment of the radiation irradiation apparatus 20 which concerns on this invention is described based on drawing.
FIG. 10 is a schematic diagram showing the flattening filter 30 of the radiation irradiation apparatus 20 in the present embodiment.
This embodiment is different from the above-described fourth embodiment in respect of the pipe 33, and the other corresponding components are denoted by the same reference numerals and description thereof is omitted.

In the present embodiment, as shown in FIG. 10, an inner pipe 33p communicating with the inside of the inner room 31A is provided as a double pipe at the center of the container 31, and an inner pipe 33q communicating with the inside of the outer room 31B is provided. Provided.
The inner pipe 33p is located outside the double pipe erected at the center of the container 31, extends to the vicinity of the top part 31b, and is provided on the bottom part 31a on the inner side of the inner side part 31f. Is connected.
The inner pipe 33q is positioned inside the double pipe erected at the center of the container 31, extends to the vicinity of the top 31b and penetrates the inner side surface 31f, and on the outer side of the inner side surface 31f. The piping 33b provided in the bottom part 31a used as the inner side of the side part 31c is connected.

Further, a pipe line is connected to the valve 34a side through the valve 35p on the pipe 33b side from the valve 35b, and a valve 34q is provided on the pipe 32a side from the valve 34a to supply liquid into the inner pipe 33q. Can be possible. Thereby, when the inner chamber 31A is filled with the liquid, the inner pipe 33q can also be filled with the liquid.

In the radiation irradiation apparatus 20 of the present embodiment, the same effects as those of the fourth embodiment described above can be obtained, and the end openings of the inner pipes 33p and 33q are near the tops of the inner side surface portion 31f and the side surface portion 31c. Therefore, it is possible to suitably discharge gas from the inner room 31A and the outer room 31B from the inner pipes 33p and 33q, and reliably discharge gas in each of the inner room 31A and the outer room 31B. In addition, it becomes easy to fill the liquid, and it becomes possible to reliably shield the dose set in the initial stage. At the same time, the pipe 33 can be arranged without penetrating the collimator 24.

Hereinafter, 6th Embodiment of the radiation irradiation apparatus 20 which concerns on this invention is described based on drawing.
FIG. 11 is a schematic diagram showing the flattening filter 30 of the radiation irradiation apparatus 20 in the present embodiment.
This embodiment is different from the first to fifth embodiments described above with respect to the number of sections of the container 31, and other corresponding components are denoted by the same reference numerals and description thereof is omitted.

In the present embodiment, the interior of the container 31 is configured to have a room divided into a plurality of sections, and specifically, as shown in FIG. 11, the side surface forming the outer slope of the container 31 in the container 31. An inner side surface portion 31s is erected on the inner side of the portion 31c and is lower than the overall height of the container 31, and an inner side surface portion 31f is erected on the inner side of the inner side surface portion 31s and lower than the overall height of the inner side surface portion 31s.

Like the inner side surface portion 31f, the inner side surface portion 31s has a conical shape, and forms a middle chamber 31C together with the outer surface of the inner side surface portion 31f and the bottom portion 31a outside the inner side surface portion 31f and inside the inner side surface portion 31s. ing.
The inner side surface portion 31f forms an inner room 31A together with the central portion of the bottom portion 31a.
A space serving as an outer room 31B is formed between the inner side surface portion 31s, the side surface portion 31c, and the bottom portion 31a that is outside the inner side surface portion 31s.

In the inner room 31A, an inner pipe 33m is provided inside the inner room 31A.
The inner piping 33m extends to the vicinity of the top portion 31b side along the inner side of the inner side surface portion 31f, and is connected to the piping 33a provided on the bottom portion 31a on the inner side of the inner side surface portion 31f.
The pipe 32a is connected to the liquid supply source 34 via the valve 34a as the liquid supply means 32A, and the pipe 33a is connected to the gas discharge source 35 via the valve 35a as the gas discharge means 33A to the inner room 31A. Liquid supply / gas discharge and liquid discharge / gas supply are possible.

In the middle room 31C, an inner pipe 33s is provided inside the middle room 31C, and a pipe 32c is connected to a bottom part 31a that is inside the middle side surface part 31s.
The inner pipe 33s extends to the vicinity of the top part 31b side along the inner side of the middle side surface part 31s, and is connected to a pipe 33c provided on the bottom part 31a on the inner side of the middle side part 31s.
The pipe 33c is connected to the liquid supply source 34 via the valve 34c as the liquid supply means 32A, and the pipe 33c is connected to the gas discharge source 35 via the valve 35c as the gas discharge means 33A to the middle chamber 31C. Liquid supply / gas discharge and liquid discharge / gas supply are possible.

In the outer room 31B, an inner pipe 33n is provided inside the outer room 31B. The inner pipe 33n extends along the inner side of the side part 31c to the vicinity of the top part 31b, and is connected to a pipe 33b provided on the bottom part 31a which is outside the inner side part 31s and inside the side part 31c. . The pipe 32b is connected to the liquid supply source 34 via the valve 34b as the liquid supply means 32A, and the pipe 33b is connected to the gas discharge source 35 via the valve 35b as the gas discharge means 33A to the outer room 31B. Liquid supply / gas discharge and liquid discharge / gas supply are possible.

By operating the liquid supply means 32A and the gas discharge means 33A with the valve 34a and the valve 35a opened, the liquid supply / gas discharge and liquid discharge to the inner room 31A in the inner room 31A that is the inner space of the inner side surface portion 31f.・ Gas supply is possible.

By operating the liquid supply means 32A and the gas discharge means 33A with the valve 34c and the valve 35c opened, the liquid to the middle room 31C is obtained in the middle room 31C which is the outer space of the inner side face 31f inside the middle side face 31s. Supply / gas discharge and liquid discharge / gas supply are possible.

Further, by operating the liquid supply means 32A and the gas discharge means 33A with the valve 34b and the valve 35b opened, the liquid supply / gas discharge to the outer room 31B is performed in the outer room 31B which is the outer space of the inner side surface portion 31s. In addition, liquid discharge and gas supply are possible.

Thus, the inner room 31A, which is the inner space of the inner side surface portion 31f, is not filled with the liquid in the middle room 31C and the outer room 31B, which are the outer spaces of the inner side surface portion 31f, and the radiation dose in this portion is not reduced. Can be filled with a liquid, and the radiation dose can be reduced only in this portion. Also, the inner room 31A that is the inner space of the inner side surface portion 31f and the middle room 31C that is the outer space of the inner side surface portion 31f inside the inner side surface portion 31s are filled with liquid, and the outer room 31B is filled with liquid. Without reducing the radiation dose in this portion. Moreover, it is possible to fill all of the inner room 31A, the middle room 31C, and the outer room 31B with liquid. Further, it is possible to fill the middle chamber 31C with liquid and not fill the inner chamber 31A and the outer chamber 31B with liquid.

Thereby, flattening corresponding to the electron beam to be used can be achieved without providing flatness filters made of a plurality of differently shaped solids.

In the radiation irradiation apparatus 20 of the present embodiment, it is possible to achieve the same effects as the first to fifth embodiments described above, and further, the inner room 31A, the middle room 31C, and the outer room 31B of the container 31. By making it possible to switch supply / discharge of liquid and gas to / from, the flattened state can be easily switched.
Further, by switching the valves 34a, 34b, 35c, 35a, 35b, and 35c as appropriate to operate the liquid supply means 32A and the gas discharge means 33A, the liquid filling state in the inner room 31A, the middle room 31C, and the outer room 31B is achieved. By switching, the mode can be easily switched.

In each of the above-described embodiments, X-rays are used as treatment bundles. However, it is also possible to move the target 22 and use electron beams as treatment bundles. In this case, the container 31 of the flatness filter 30 can be configured to also serve as a scattering foil.

DESCRIPTION OF SYMBOLS 1 Radiotherapy apparatus 20 Radiation irradiation apparatus 21 Electron beam accelerator 22 Target 24 Collimator 30 Flattening filter 31 Container 31a Bottom part 31b Top part 31c Side part 31A Inner room 31C Middle room 31B Outer room 31f Inner side part 31s Middle side parts 32, 33, 32a 33a, 32b, 33b, 32c, 33c Pipe 33g Inner slope 33f Opening 33m, 33n, 33p, 33q, 33t Inner pipe 32A Liquid supply means 34 Liquid supply sources 34a, 34b, 35c, 35a, 35b, 35c Valve 33A Gas discharge Means 35 Gas emission source

Claims (6)

A radiation source;
A filter for attenuating radiation emitted from the radiation source,
A container capable of containing a liquid that attenuates radiation therein;
A radiation irradiating apparatus, comprising: a switching unit capable of putting liquid into and out of the container. The radiation irradiation apparatus according to claim 1, wherein the container is formed in a weight shape having a vertex on the radiation source side. The said switching means has the liquid supply means which performs the liquid supply / discharge in the said container, and the gas discharge means which performs the gas discharge / supply in the said container, The Claim 1 or 2 characterized by the above-mentioned. Radiation irradiation equipment. The radiation irradiating apparatus according to any one of claims 1 to 3, wherein the container has a plurality of rooms partitioned inside, and the switching means can allow liquid to be taken in and out of each room. The radiation irradiation apparatus according to claim 4, wherein the plurality of rooms are concentrically partitioned around a radiation irradiation axis inside the container. 6. A collimator is provided around a radiation irradiation axis of the filter, and a pipe in the switching unit penetrates the collimator, and the pipe is bent in the collimator. The radiation irradiation apparatus as described.

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