JP3336782B2 - Radiation irradiation device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radiation irradiating apparatus, for example, a medical radiation irradiating apparatus.

[0002]

2. Description of the Related Art FIG. 11 is a cross-sectional view showing radiation irradiation of a conventional medical radiation irradiation apparatus. Reference numeral 1 denotes an X-ray source for generating X-rays as one mode of radiation, and 2 denotes a movable member in a direction orthogonal to the X-ray irradiation direction. An X-ray movable aperture (collimator) made of a shielding material such as lead or heavy metal, and an X-ray restricted by the collimator 2. The irradiation beam cone 4 indicates the contour of an irradiation target such as a diseased part of a human body that needs to be irradiated with radiation.

Here, in order to irradiate the irradiation target 4 from multiple directions, the radiation source 1 rotates around the irradiation target 4 in a circular shape by a rotation mechanism that rotates the gantry by a motor provided in a fixed part. In FIG. 11, the radiation source 11, the collimator 21, and the radiation cone 31 show radiation irradiation after being rotated by a predetermined angle. Reference numeral 5 denotes the center of rotation (isocenter) of the radiation sources 1 and 11. FIG. 12 shows the radiation source 1 for the radiation target.
It is a figure which shows the dose distribution of radiation at the time of irradiating more radiation, and the irradiation target 4 is shown with the dotted line in FIG. 12 on account of description. Reference numeral 6 denotes an area irradiated with radiation,
Reference numeral 7 denotes an extra irradiation area outside the irradiation target 4.

Next, the operation will be described. In FIG. 11, the X-ray emitted from the X-ray source 1 is restricted by the collimator 2 to an irradiation field within the range of the irradiation cone 3. At this time, the irradiation line cone 3 is set as a line segment circumscribing the irradiation target contour 4. Next, the radiation source 1 rotates about the radiation source rotation center 5, and the collimator 21 is set so that the line segment circumscribing the irradiation target contour 4 becomes the irradiation ray cone 31 at each rotation angle. In this way, while controlling the collimators 2 and 21, the radiation sources 1 and 11
When the irradiation target has irregularities,
As shown in FIG. 2, the dose distribution of the X-ray is as shown in the irradiation area 6. At this time, an extra irradiation area 7 is formed outside the irradiation target 4 and an area that should not be irradiated is irradiated with radiation. Particularly in medical radiation irradiation equipment,
Radiation will be applied to areas other than the affected area,
It will have a negative effect on normal tissue.

Conventional example 2. FIG. 13 is a cross-sectional view showing radiation irradiation of a conventional medical radiation irradiation apparatus, in which 12 is an X-ray source that generates X-rays as one mode of radiation, and 22 is movable in a direction orthogonal to the X-ray irradiation direction. An X-ray movable diaphragm (collimator) 32, which has a function of restricting the direction of irradiation of X-rays emitted from the X-ray source 12 and is made of a shielding material of lead or heavy metal, and 32 is a collimator 2
The X-ray irradiation cone 4 limited by 2 indicates an outline of an irradiation target such as a diseased part of a human body that needs to be irradiated with radiation.

In the second conventional example, the collimator 22 is controlled so that the irradiation area is limited to a part of the irradiation target 4 so that the irradiation target 4 is irradiated with the radiation in a divided manner. FIG.
In 3, the radiation source 13, the collimator 23, the radiation cone 33
Shows the configuration after the irradiation area has been moved. 5 is the source 1
The center of rotation (isocenter) of 2, 13 is shown. FIG.
FIG. 14 is a diagram showing a dose distribution of radiation when the radiation source 1 irradiates radiation to the irradiation target. In FIG. 14, the irradiation target 41 is indicated by a dotted line for convenience of explanation. Reference numeral 61 denotes an area to be irradiated with radiation, and 71 denotes an extra irradiation area outside the irradiation target 41.

Next, the operation will be described. In FIG. 13, the X-ray emitted from the X-ray source 12 has its irradiation field restricted by the collimator 22 within the range of the irradiation cone 32, and is irradiated with a constant dose. Next, with the source position 12 fixed, the collimator 23 is moved to limit the irradiation field to within the range of the irradiation cone 33, and a constant dose is applied. In this manner, the area within the circumscribed area of the irradiation target 4 is irradiated by dividing the area by the collimators 22 and 23. At this time, the irradiation dose generated from the radiation source 13 is reduced by a control unit (not shown) when the divided region passes through the concave portion of the target region 4. Next, as in Conventional Example 1, X
The source 1 is rotated, and the above operation is repeated. This allows
When the irradiation target has irregularities, the X-ray dose distribution is as shown in the irradiation region 61 as shown in FIG. It is almost superimposed on the shape of the irradiation target 41, and the dose of the concave portion 71 can be suppressed.

[0008]

The radiation irradiating apparatus of the prior art 1 is configured as described above, and irradiates the entire area to be irradiated with an equal amount of radiation. There was a problem that it was not possible. In addition, there is a problem in that the concave portion is irradiated with an excessive dose when the shape of the irradiation target is a shape having irregularities. On the other hand, in the linear acceleration device of the conventional example 2, since the irradiation target is divided and irradiated with the radiation, there is a problem that it takes time to irradiate the entire irradiation target.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide a radiation irradiation apparatus which can freely control the dose distribution of irradiation and can irradiate the entire irradiation target in a short time. And

[0010]

According to a first aspect of the present invention, there is provided a radiation therapy apparatus comprising: a radiation source for generating radiation; and a collimator for restricting transmission of the radiation. , On a plane that moves from the driving unit and intersects the radiation irradiation direction
Divided into a plurality of parts, and the driving unit is at least partially
Of the irradiation field independently of the other divisions
Move to any position to control the dose in the area
The first shielding member configured as described above, and the radiation moved by the driving unit and irradiated to the irradiation target from the radiation source
A second shielding member that is provided alongside the first shielding member along an irradiation path that passes therethrough and that restricts transmission of the radiation.

[0011] Radiation therapy system according to the invention of claim 2, further 2 ⁿ t is the thickness of said second shielding member when the thickness of the first shielding member and the t (n is an integer) It was done.

[0012] In the radiotherapy apparatus according to the third aspect of the present invention, further, the second shielding member may be illuminated with the radiation.
The drive unit divides at least a part of the second shielding member into a predetermined area in the irradiation field independently of other divided parts on a plane intersecting the shooting direction.
It is moved to an arbitrary position to control the dose in the area .

In the radiotherapy apparatus according to the present invention, the divided portion of the first shielding member and the divided portion of the second shielding member are respectively positioned at arbitrary positions according to the irradiation object. is there.

According to a fifth aspect of the present invention, there is provided a radiotherapy apparatus including a rotation mechanism for rotating a radiation source and a collimator around an irradiation target, and a control unit for restricting irradiation of a part other than the irradiation target with radiation. Things.

[0015]

In the radiotherapy apparatus according to the first aspect of the present invention, the first shielding member is moved by the driving unit,
The second shielding member provided alongside the first shielding member in the radiation irradiation direction restricts the transmission of the radiation, and moves by the driving unit and restricts the transmission of the radiation. Also,
On the surface where the first shielding material intersects the radiation irradiation direction
It is divided into a plurality of parts, and at least one
Part of the irradiation field is independent of the other
Move to an arbitrary position to control the dose in a certain area
You.

[0016] In radiation therapy system according to the invention of claim 2, (n is an integer) 2 ⁿ t is the thickness of said second shielding member when the thickness of the first shielding member and t is a , Adjust the radiation dose step by step.

[0017] In the radiotherapy apparatus according to the third aspect of the present invention, the second shielding member intersects the irradiation direction of the radiation.
The surface is divided into a plurality of portions, and at least some of the divided portions of the second shielding material are controlled by the driving section independently of the other divided portions to control the dose in a predetermined region in the irradiation field.
Move to any position .

In the radiotherapy apparatus according to the fourth aspect of the present invention, the divided portion of the first shielding member and the divided portion of the second shielding member are respectively positioned at arbitrary positions according to the irradiation object.

In the radiotherapy apparatus according to the fifth aspect of the present invention, the radiation source and the collimator are rotated around the irradiation target by the rotation mechanism, and the control unit limits the irradiation of radiation to parts other than the irradiation target.

[0020]

[Embodiment 1] An embodiment of the present invention will be described below with reference to the drawings. FIG.
FIG. 2 is a cross-sectional view illustrating radiation irradiation of the radiation irradiation apparatus according to the first embodiment, and FIG. 2 is a diagram illustrating an upper surface of a collimator unit of the radiation irradiation apparatus. 1 is a cross-sectional view taken along the line cc ′ of FIG.
It is shown.

In FIG. 1, reference numeral 1 denotes an X-ray source for generating X-rays as one mode of radiation, and 2 denotes a direction in which the X-ray emitted from the X-ray source 1 is movable in a direction orthogonal to the X-ray irradiation direction. Is a movable X-ray diaphragm (collimator) made of a shielding material of lead or heavy metal, and has a plurality of shielding materials 2a, 2b, and 2c having a thickness t. The movement of the shielding members 2a, 2b, and 2c is individually controlled by driving units such as a gear, a motor, and a control unit. Numeral 3 denotes an X-ray irradiation cone limited by the collimator 2, and in particular, 3a,
3b and 3c show X-ray irradiation paths. Further, the lower part of the collimator 2 indicates the dose of radiation that has passed through the collimator 2.

Next, the operation will be described. The radiation cone of the X-ray generated from the X-ray source 1 is limited by a primary collimator (not shown), and is irradiated to the collimator 2. The radiation cone of the X-ray radiated to the collimator 2 is further restricted by the collimator 2. The collimator 2 is divided into a plurality of shielding plates 2a, 2b, 2c,
The more irradiated X-rays pass through the shielding members 2a, 2b, 2c. Here, the transmittance of the X-rays varies depending on the thickness of the shield passing therethrough.

In the case of the first embodiment, the route 3a is 2a, 2b,
The path 3b passes through two shields 2b and 2c, and the path 3c passes through one shield 2c. Therefore, the X-ray transmittance differs between the paths 3a, 3b, and 3c. Specifically, the transmittance D = exp (−μ · 3t) in the route 3a, and the transmittance D in the route 3b.
= Exp (-μ · 2t), transmittance D = exp in path 3c
(-Μt). Here, μ is the X-ray absorption coefficient of the shielding material.

The positions of the shielding members 2a, 2b, and 2c can be independently changed by driving units such as a gear, a motor, and a control unit. Therefore, by adjusting the position of each shielding material, the dose in the subdivided region in the irradiation field can be changed, and irradiation can be performed in a short time according to the shape of the irradiation target.

Although three shielding members are used in the above embodiment, the number of shielding members is not limited to this, and the number is determined in consideration of the complexity of control, economy, and the like. Good. On the other hand, by increasing the number of shielding materials, the irradiation dose can be specified with higher accuracy.

In the above embodiment, the thickness of the shielding material is t and the thickness of all the shielding materials is the same. However, the thicknesses are not necessarily the same. However, if the thickness of the shielding material is the same, there is an effect that the production becomes easy and the control becomes easy due to the weight and the like.

As described above, in the radiotherapy apparatus according to the first embodiment, a radiation source for generating radiation;
A collimator that restricts the transmission of the radiation, and in particular, the collimator moves from a driving unit, and a first shielding member that restricts the transmission of the radiation; and a first shielding member that moves by the driving unit and moves in the radiation irradiation direction. Since the second shielding member is provided alongside the shielding member and restricts the transmission of radiation, the radiation dose can be changed in the irradiation region. Here, the first shielding material and the second shielding material correspond to any one of the shielding materials 2a, 2b, and 2c in the first embodiment.

Embodiment 2 FIG. The shielding members 2a, 2b, and 2c in the first embodiment each have a uniform thickness t, but in the second embodiment, each thickness is changed with a certain regularity. FIG. 3 is an irradiation sectional view showing Example 2, in which 1 is an X-ray source,
2a, 2b, 2c and 2d have thicknesses t, 2t and 4 respectively.
t, 8t. That is, the thickness of each shielding material is 2 ⁰
t, 2 ¹ t, 2 ² t, and 2 ³ t. The movement of the shielding members 2a, 2b, 2c, and 2d is individually controlled by driving units such as gears, motors, and control units (not shown).

Next, the operation will be described. X-rays emitted from the X-ray source 1 are restricted by the collimator 2. The shielding members 2a, 2b, 2c, 2d have thicknesses t, 2t, 4 respectively.
Since t and 8t, a stepwise transmittance D represented by the following equation can be obtained by a combination of the respective shielding members.

[0030]

(Equation 1)

The radiotherapy apparatus according to the invention described in Example 2 further 2 ⁿ t is the thickness of said second shielding member when the thickness of the first shielding member and the t (n is an integer) Therefore, the dose of radiation can be changed stepwise in the irradiation area.

Although four shielding members are used in the above embodiment, the number of shielding members is not limited to this, and the number is determined in consideration of the complexity of control, economy, and the like. By increasing the number of shielding members, the irradiation dose can be more finely specified.

In the second embodiment, the thickness of the shielding material in the vicinity of the radiation source 1 is defined as t, and as the distance from the radiation source 1 increases, 2t / 4t
・ 8t, but not limited to this, 8t ・ 4t ・ 2t
* T or 2t * 4t * 8t * t.

Embodiment 3 FIG. In the third embodiment, in particular, a plurality of shielding mechanisms are arranged on a plane orthogonal to the X-ray irradiation direction so that the dose in a specific area in the irradiation field can be selected and controlled. 4 and 5 show an irradiation sectional view and a top view of the radiation irradiation apparatus according to the third embodiment. 4 and 5, reference numerals 2a, 2b, and 2c denote shielding members, and a plurality of shielding members are arranged on a surface orthogonal to the X-ray irradiation direction. 1 is an X-ray source. The irradiation cross section in FIG. 4 is the cross section c in FIG.
-C '.

Next, the operation will be described. X-rays emitted from the X-ray source 1 are restricted when passing through the collimator 2. It is divided into a path that passes only the shielding material 2a, a path that passes only the shielding material 2b, a path that passes the shielding materials 2b and 2c, and a path that passes the shielding materials 2a and 2b, depending on the thickness of each shielding material. X-rays pass through. The dose is shown at the bottom of FIG. That is, an arbitrary radiation dose is selected by a combination of the respective shielding members. The position of each of these shielding members is determined by a drive unit such as a gear, a motor, a control unit, or the like in two ways, whether or not X-rays are restricted. The radiation dose is controlled in this manner, and the irradiation target (not shown) is irradiated.

The collimator according to the third embodiment is composed of three layers of shielding members, each of which is divided into a plurality of pieces. However, the present invention is not limited to this. Layers and undivided layers may be mixed.

In the radiotherapy apparatus according to the invention described in the third embodiment, the first shielding member is divided into a plurality of portions on a plane intersecting with the radiation irradiation direction, and the driving section has at least a part of the divided portions. Since it is moved independently of the other divided parts, the radiation dose can be changed according to the shape and properties of the irradiation target.

Further, the second shielding member is divided into a plurality of portions on a plane intersecting with the radiation irradiation direction corresponding to the divided portion of the first shielding member, and the driving section is provided in the second shielding member. Since at least some of the divided parts are moved independently of the other divided parts, the dose of radiation can be changed more accurately according to the shape and properties of the irradiation target.

Embodiment 4 FIG. In the third embodiment, the position of each shielding member is determined in two ways, that is, whether or not to restrict the X-ray. However, in the fourth embodiment, the position of each shielding member is set as an irradiation target so as to form an irregular irradiation field. It is controlled to match any position along.
FIG. 6 is a cross-sectional view illustrating a collimator section of the radiation irradiation apparatus according to the fourth embodiment. In FIG. 6, 2a, 2b, 2c
Is a shielding material, and a plurality of shielding materials are arranged on a surface orthogonal to the X-ray irradiation direction. 1 is an X-ray source. The lower section in FIG. 6 shows the upper section cc ′.

Next, the operation will be described. X-rays emitted from the X-ray source 1 are restricted when passing through the collimator 2. It is divided into a path that passes only the shielding material 2a, a path that passes only the shielding material 2b, a path that passes the shielding materials 2b and 2c, and a path that passes the shielding materials 2a and 2b, depending on the thickness of each shielding material. X-rays pass through. The dose is shown at the bottom of FIG. That is, an arbitrary radiation dose is selected by a combination of the respective shielding members.

In particular, the position of each shielding material is controlled so as to be adjusted to an arbitrary position along the irradiation object so as to form an irregular irradiation field. Therefore, each shielding material is individually controlled by a control unit (not shown) via a pulse motor, a rotary encoder, and the like so as to be located at an arbitrary position.

As described above, in the invention described in the fourth embodiment, since the position of each shielding material is controlled so as to be adjusted to an arbitrary position along the irradiation target, radiation can be applied in the shape of the irradiation target. .

In the third and fourth embodiments, the shielding material is divided into a plurality of portions on a plane intersecting with the radiation irradiation direction. However, it is not necessary to divide all the layers, and only some of the layers may be used. In addition, the plurality of divided shielding members are individually driven independently, but are not limited thereto, and may be partially fixed or linked with other related shielding members.

Embodiment 5 FIG. In the above embodiment, the shielding material in the collimator has a multilayer structure, and the distribution of irradiation dose is variable. In the fifth embodiment, the collimator having the structure is further rotated around the irradiation target together with the radiation source. is there. FIG. 7 is an irradiation sectional view for explaining the fifth embodiment. In the figure, 1 is an X-ray source, 2 is movable in a direction orthogonal to the X-ray irradiation direction, has a function of limiting the irradiation direction of the X-rays irradiated from the X-ray source 1, and is made of a shielding material of lead or heavy metal. The configured X-ray movable diaphragm (collimator) 4 indicates an outline of an irradiation target such as a diseased part of a human body that needs to be irradiated with radiation.

Here, in order to irradiate the irradiation object 4 from multiple directions, the radiation source 1 is rotated around the irradiation object 4 by a rotating mechanism in a circular shape. For example, the gantry is rotated by a motor provided in the fixed portion, thereby rotating the gantry in a circular shape. In FIG. 7, the radiation source 11 and the collimator 21 show radiation irradiation after being rotated by a predetermined angle. Reference numeral 5 denotes the center of rotation (isocenter) of the radiation sources 1 and 11.

FIG. 8 is a diagram showing the dose distribution of radiation when the radiation source 1 irradiates radiation to the irradiation target. In FIG. 8, reference numeral 6 denotes an area irradiated with radiation. This is the same area as the irradiation target 4. Reference numeral 7 denotes an extra irradiation area outside the irradiation target 4.

Next, the operation will be described. In FIG. 7, the X-ray emitted from the X-ray source 1 is restricted by the collimator 2. Then, the X-ray source 1 is rotated together with the collimator 2 to irradiate the irradiation target 4 with X-rays from multiple directions. At this time, the combination of the shielding materials is changed by the control unit so as to reduce the dose passing through the concave portion of the irradiation target 4. Specifically, the shielding material 2 corresponding to the X-ray passing through the concave portion of the irradiation target 4
In the collimator 2 in the figure, the center portion is increased, and in the collimator 21, the vicinity of the end portion is increased so that the portion becomes thicker.

By controlling in this way, the irradiation target 4
Can be reduced, and the distribution of the irradiation dose according to the irradiation target can be obtained. That is,
As shown in FIG. 6, a region 6 to be irradiated with X-rays along the irradiation target 4 can be obtained, and irradiation of the region 7 with X-rays can be reduced. Particularly, in a medical radiation irradiating apparatus, it is possible to prevent radiation from being irradiated to a part other than the diseased part to be irradiated, and to alleviate adverse effects on normal tissues.

On the other hand, since the irradiation area is not divided and the collimator is moved for each area as in the conventional example 2, the irradiation target can be irradiated in a short time.

As described above, the radiation therapy apparatus according to the fifth embodiment of the present invention has a rotation mechanism for rotating a radiation source and a collimator around an irradiation target, and a control for limiting irradiation of radiation to portions other than the irradiation target. Since the part is provided, the irradiation target having irregularities can be irradiated in a short time without irradiating unnecessary parts with the radiation.

Embodiment 6 FIG. FIG. 9 and FIG. 10 are explanatory diagrams in the case where the irradiation of the radiation of the first to fifth embodiments is specifically applied to a medical radiation irradiation apparatus. 9 and 10, 81 is a gantry (rotating part), 82 is an X-ray applicator that narrows the beam diameter with a lead tube, 83 is a control part, a fixed part having a pulsar modulator, and the like.
Reference numeral 84 denotes a treatment table top on which a patient is placed, and reference numeral 85 denotes a treatment table support serving as a rotation center for supporting the treatment table. The treatment table support is rotated during normal treatment, but is not rotated during surgery treatment. Reference numeral 86 denotes the rotation of the treatment table isocenter, which is the center of rotation during normal surgery treatment. Reference numeral 87 denotes a C-arm gantry that rotates in the ψ direction.

Next, the operation will be described. In the radiotherapy apparatus shown in FIG. 9, X-rays are emitted from an X-ray emitting unit provided inside the gantry 81 in accordance with an instruction from a control unit provided inside the fixed unit 83. The collimator provided between the gantry 81 and the X-ray applicator 82 limits the X-ray irradiation field to, for example, about 0 to 40 × 40 cm. In particular, the collimator of the present invention is movable in a direction orthogonal to the X-ray irradiation direction, has a function of restricting the irradiation direction of the X-rays emitted from the X-ray source 1, and includes a plurality of shielding materials of lead or heavy metal. Have been. The specific configuration of the collimator is the same as that described in detail in the first to fifth embodiments.

The irradiation field of the X-rays limited by the collimator is further narrowed by the X-ray applicator 82. For example, the diameter is reduced to about 0.5 cm to 3 cm. Then, the X-ray is irradiated to the irradiation target of the patient placed on the treatment table top 84. By rotating the gantry 81 with respect to the fixed portion 83 and moving the treatment table top 84 with respect to the treatment table support 85, the irradiation target is irradiated with X-rays from multiple directions.

In the radiation therapy apparatus shown in FIG. 10, the irradiation unit further rotates in the ψ direction around the other rotation axis intersecting the rotation axis with the rotation irradiation in the φ direction of the radiation source, so that irradiation is performed from a three-dimensional direction. I do.

In the first to sixth embodiments, X-rays are used as radiation for irradiation. However, the present invention is not limited to this, and any radiation can be used as long as irradiation can be restricted by a collimator. For example, γ emitted with cobalt as the target
There is a line.

Further, the material of the shielding material used for the collimator is determined in relation to the radiation to be irradiated, and is not limited to lead and heavy metals as described in the embodiment.
What is necessary is just to reduce the radiation dose by a certain amount. Also, a material that shields radiation almost completely in some shielding materials may be used.

Although the collimators in the first to sixth embodiments are bilaterally symmetric, the present invention is not limited to this, and only one of them may have a multilayer structure. Alternatively, only one of the shielding members may be movable, and the other may be fixed.

Although the same shielding material is used in each of the above embodiments, various materials having different transmittances may be used. For example, by providing a shielding material made of a material having an extremely low transmittance, it is not necessary to increase the thickness of the shielding material to completely shield radiation, and the thickness of the collimator as a whole can be reduced.

[0059]

As described above, in the radiation therapy apparatus according to the first aspect of the present invention, in the radiation irradiation apparatus having a radiation source for generating radiation and a collimator for restricting transmission of the radiation, the collimator is , On a plane that moves from the driving unit and intersects the radiation irradiation direction
Divided into a plurality of parts, and the driving unit is at least partially
Of the irradiation field independently of the other divisions
Move to any position to control the dose in the area
The first shielding member configured as described above, and the radiation moved by the driving unit and irradiated to the irradiation target from the radiation source
Since there is provided a second shielding member that is provided alongside the first shielding member along the passing irradiation path and limits the transmission of the radiation, the radiation dose can be changed in the irradiation region. In addition, according to the shape and properties of the irradiation target
Thus, the radiation dose can be changed.

[0060] The radiation therapy system according to the invention of claim 2 further 2 ⁿ t is the thickness of said second shielding member when the thickness of the first shielding member and the t (n is an integer) Therefore, the dose of radiation can be changed stepwise in the irradiation area.

[0061] In the radiotherapy apparatus according to the third aspect of the present invention, further, the second shielding member may be configured to irradiate the radiation.
The drive unit divides at least a part of the second shielding member into a predetermined area in the irradiation field independently of other divided parts on a plane intersecting the shooting direction.
Since the radiation dose is moved to an arbitrary position so as to control the radiation dose in the region , the radiation dose is changed more accurately than the radiation treatment apparatus according to the first aspect of the present invention in accordance with the shape and properties of the irradiation target. be able to.

In the radiotherapy apparatus according to the fourth aspect of the present invention, the divided portion of the first shielding member and the divided portion of the second shielding member are respectively positioned at arbitrary positions according to the irradiation object. Irradiation can be performed according to the shape of the irradiation target.

In the radiotherapy apparatus according to the fifth aspect of the present invention, there is provided a rotation mechanism for rotating the radiation source and the collimator around the irradiation target, and a control unit for restricting irradiation of a part other than the irradiation target with radiation. Therefore, it is possible to irradiate the irradiation target having irregularities in a short time without irradiating unnecessary portions with radiation.

[Brief description of the drawings]

FIG. 1 is a diagram showing a cross section and a dose distribution of a radiation irradiation apparatus according to an embodiment of the present invention.

FIG. 2 is a diagram illustrating an upper surface of a collimator unit of the radiation irradiation apparatus according to the embodiment of the present invention.

FIG. 3 is a diagram showing a cross section of the radiation irradiation apparatus according to one embodiment of the present invention.

FIG. 4 is a diagram showing a cross section and a dose distribution of a radiation irradiation apparatus according to an embodiment of the present invention.

FIG. 5 is a diagram showing an upper surface of a collimator section of the radiation irradiation apparatus according to one embodiment of the present invention.

FIG. 6 is a diagram showing a cross section and a top surface of the radiation irradiation apparatus according to one embodiment of the present invention.

FIG. 7 is a diagram showing a cross section of the radiation irradiation apparatus according to one embodiment of the present invention.

FIG. 8 is a diagram showing radiation irradiation by the radiation irradiation device according to one embodiment of the present invention.

FIG. 9 is a view showing a radiation irradiation apparatus according to an embodiment of the present invention.

FIG. 10 is a view showing a radiation irradiation apparatus according to an embodiment of the present invention.

FIG. 11 is a sectional view showing a radiation irradiation apparatus according to Conventional Example 1.

FIG. 12 is a diagram showing a dose distribution of radiation in a radiotherapy apparatus according to Conventional Example 1.

FIG. 13 is a sectional view showing a radiation irradiation apparatus according to Conventional Example 2.

FIG. 14 is a diagram showing a radiation dose distribution in a radiotherapy apparatus according to Conventional Example 2.

[Explanation of symbols]

1 X-ray source, 2 collimator, 2a-2d shielding material,
4 Irradiation target

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) A61N 5/10

Claims (5)

(57) [Claims] 1. A radiation irradiating apparatus comprising: a radiation source for generating radiation; and a collimator for restricting transmission of the radiation, wherein the collimator is moved by a driving unit to illuminate the radiation.
Divided into multiple parts on the plane intersecting the shooting direction,
The driving unit converts at least a part of the divided part into another divided part.
Independently controls the dose in a given area within the irradiation field.
A first shielding member configured to be moved to an arbitrary position as described above;
The first along the irradiation path through which the irradiated radiation passes
And a second shielding member provided in parallel with the shielding member for limiting transmission of the radiation. 2. The method according to claim 1, wherein the thickness of the second shielding material is 2 nt (n is an integer), ^where t is the thickness of the first shielding material. Radiation irradiation device. 3. The radiation shielding direction of the second shielding member is
Is divided into a plurality of portions on a plane intersecting with, and the driving section separates at least some of the divided portions of the second shielding member from a predetermined region in the irradiation field independently of other divided portions.
The radiation irradiation apparatus according to claim 1, wherein the radiation irradiation apparatus is moved to an arbitrary position so as to control a dose of the radiation. 4. The radiation according to claim 3, wherein the divided part of the first shielding member and the divided part of the second shielding member are respectively positioned at arbitrary positions according to an irradiation target. Irradiation device. 5. The apparatus according to claim 1, further comprising a rotation mechanism configured to rotate the radiation source and the collimator around an irradiation target, and a control unit configured to limit irradiation of radiation to a portion other than the irradiation target. The radiation irradiating apparatus according to any one of claims 4 to 7 .