JP2005024475A - Range correction unit and heavy charged particle beam radiation apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provided a range correction unit and a heavy charged particle beam radiation apparatus realizing reduction in time, cost and the like for medical treatment by automatically controlling the range of radiation against a target for every target. <P>SOLUTION: The heavy charged particle beam radiation apparatus (heavy particle beam cancer treatment apparatus) 11 is provided with the range correction unit 12 for controlling the range of the radiation beam 1 against the target 4 by absorbing the energy of the radiation beam 1. The range correction unit 12 comprises an energy absorption layer 14 made of a plurality of leaves 13 absorbing the energy of the radiation beam 1 and a plurality of actuators 15 for advancing/retreating the leaves 13 of the energy absorption layer 14 to/from the path of the beam 1. The leaves 13 are formed in a rectangular plate shape, and are arranged parallelly in a plurality of rows in the Y direction and opposite in its lengthwise direction (X direction). <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a range compensation device and a heavy charged particle beam irradiation device that three-dimensionally control a range (stop position) of radiation such as a heavy particle beam, a proton beam, and an ion beam with respect to a target.

  A heavy particle beam cancer treatment apparatus will be described as an example of a heavy charged particle beam irradiation apparatus according to the prior art, and will be described with reference to FIGS. 15 and 16. FIG. 15 is a schematic view showing the overall configuration of a heavy particle beam cancer treatment apparatus according to the prior art, and FIG. 16 is a partially enlarged sectional view showing an irradiation part and a patient of the heavy particle beam cancer treatment apparatus in FIG. It is.

In FIG. 15, heavy ions such as carbon ions (C ⁶⁺ ) generated by a radiation source (not shown) ^{lay on the} bed 2 from an accelerator (not shown) as an irradiation beam 1 as radiation. Irradiation is directed toward a target 4 which is a tumor part in the patient 3. In addition, the irradiation beam 1 is irradiated to the target 4 in the patient 3 until the irradiation field 1 is irradiated to the irradiation field expansion device 5, the range modulation device 6, the range attenuation device 7, the multileaf collimator device 8, and the range compensation filter. By sequentially passing through 9 and the like, the dose distribution is processed so as to have an effective diameter, a thickness, and a maximum range corresponding to the three-dimensional shape of the target 4, and the target 4 is irradiated.

  Here, the irradiation field expanding device 5 includes electromagnets 5A and 5A and a scatterer 5B, and expands the cross-sectional shape of the irradiation beam 1. The range modulation device 6 is a device formed by cutting an aluminum plate or the like into a ridge shape, and expands the irradiation beam 1 in the irradiation direction (longitudinal direction). The range attenuating device 7 is configured to uniformly shorten the range of the irradiation beam 1 with respect to the target 4 by combining a plurality of energy absorbing plates 7A, 7B, 7C, 7D, 7E, and 7F having different thicknesses. It is.

  Furthermore, as shown in FIG. 16, the multileaf collimator device 8 is configured by arranging a pair of metal plates 8 </ b> A and 8 </ b> A facing each other so as to be separated from each other in a plate shape (see, for example, Patent Document 1). ). And the multileaf collimator apparatus 8 makes the cross-sectional shape of the target 4 between each metal plate 8A by separating and approaching the metal plates 8A and 8A which opposed in the length direction, respectively using an actuator (not shown). Opening 8B corresponding to is formed. For this reason, the irradiation beam 1 is processed into a beam shape corresponding to the target 4 by passing through the opening 8B, and is irradiated to the target 4.

The range compensation filter 9 is designed so that the range (stop position) of the irradiation beam 1 with respect to the target 4 matches the shape of the bottom side of the target 4 in the depth direction. For this reason, it becomes possible to prevent the exposure to the normal tissue of the deep part exceeding the target 4. FIG. Further, by performing such irradiation on the same target 4 from a plurality of directions (for example, a vertical direction and a horizontal direction), it is possible to form an irradiation region that matches the three-dimensional shape of the target 4. The range compensation filter 9 is also called a bolus, and is described in Non-Patent Document 1, for example.
Japanese translation of PCT publication No. 2001-509898 (page 9, FIG. 2) "Review of science instrument" (USA) (August 1993) Vol. 64, No. 8, P2072

  By the way, in the treatment using the heavy ion beam cancer treatment apparatus according to the prior art, if an appropriate range compensation filter 9 is not used, even a normal tissue in a deep part beyond the target 4 which is a tumor has a high dose. Since the irradiation beam 1 is irradiated, it causes a side effect. However, since the appropriate range compensation filter 9 varies depending on the shape of the target 4 in the patient 3, a suitable filter must be manufactured for each patient 3 and for each direction in which the patient 3 is irradiated. . For this reason, the following problems arise.

  That is, when the range compensation filter 9 is manufactured, an expensive numerically controlled machine tool must be used in order to cut the plastic material or the like as the base material. In addition, in order to inspect the dimensional accuracy after the processing of the range compensation filter 9, to replace the range compensation filter 9, and to store and discard the range compensation filter 9, many facilities and many hands are required. Work and management work are required, and when such a range compensation filter 9 is used, there is a problem that not only the time and cost required for treatment are expensive, but also a human error is caused manually.

  In view of the above-mentioned problems, the present invention can automatically adjust the radiation range for a target for each target, and can reduce the time, cost, etc. required for treatment, and a heavy charged particle beam irradiation. An object is to provide an apparatus.

  The present invention is configured to solve the above-mentioned problem, and the invention according to claim 1 is provided in the middle of a path of radiation irradiated from a radiation source toward a target, In a range compensator that absorbs and adjusts the range of radiation with respect to the target, a plurality of energy absorbers that absorb the energy of the radiation, and each energy absorber is advanced and retracted independently toward the path of the radiation. The range compensator includes an actuator that can be moved.

  According to the range compensating device of the first aspect, when the radiation passes through the energy absorber, the energy of the radiation is weakened, and the range of the radiation with respect to the target can be set small. On the other hand, the radiation that is directly irradiated to the target without passing through the energy absorber does not weaken the energy by the energy absorber, so that the range of the radiation with respect to the target can be set large.

  Therefore, each energy absorber is independently advanced and retracted toward the radiation path by using an actuator, so that the range of the radiation in the depth direction of the target is automatically adjusted appropriately according to the three-dimensional shape of the target. For example, when radiation is applied to an affected area that is a target of a patient, unnecessary irradiation of normal tissue can be prevented.

  According to a second aspect of the present invention, the energy absorber is a leaf made of an elongated plate-like body, and an energy absorbing layer is formed by arranging the leaves in a plurality of rows in a plate shape. It is a compensation device.

  According to the range compensator according to claim 2, the shape of the opening formed between the leaves is finely changed by moving the leaves constituting the energy absorption layer separately toward and away from the radiation path. And the range of the radiation with respect to the target can be adjusted more accurately according to the three-dimensional shape of the target.

  The invention according to claim 3 is a range compensator characterized in that a plurality of energy absorption layers are arranged along a path of radiation.

  According to the range compensation apparatus of Claim 3, the range of the radiation with respect to a target can be adjusted more finely by moving each leaf for every energy absorption layer.

  The invention according to claim 4 is a range compensation characterized in that a leaf of at least one of the plurality of energy absorption layers is moved in a direction different from a leaf of another energy absorption layer. Device.

  According to the range compensator according to claim 4, by moving the leaf of at least any one of the plurality of energy absorption layers in a direction different from the leaves of the other energy absorption layers, The range of the radiation with respect to the target can be adjusted with high accuracy according to the three-dimensional shape of the target.

  The invention according to claim 5 is characterized in that a leaf of at least one of the plurality of energy absorption layers has a plate thickness different from that of the leaves of the other energy absorption layers. It is a compensation device.

  According to the fifth aspect of the present invention, the energy of the radiation after passing through the leaf is changed depending on whether the radiation is passed through the leaf having a small thickness or the leaf having a large thickness. be able to.

  The invention according to claim 6 is characterized in that the leaf of at least one of the plurality of energy absorption layers is formed of a material having an energy absorption rate different from that of the leaves of the other energy absorption layers. It is a range compensation device.

  According to the invention described in claim 6, the energy of the radiation after passing through the leaf in the case where the radiation is passed through the leaf having a small energy absorption rate and the case in which the leaf having a large energy absorption rate is passed through. Can be changed.

  The invention according to claim 7 is characterized in that a leaf of at least one of the plurality of energy absorbing layers has a plate width different from that of the leaves of the other energy absorbing layers. It is a compensation device.

  According to the invention described in claim 7, by using a combination of a leaf having a small plate width and a leaf having a large plate width, the range of radiation with respect to the target can be adjusted with high accuracy in accordance with the three-dimensional shape of the target. it can.

  The invention according to claim 8 is the range compensator characterized in that the energy absorbing layer is configured such that a pair of leaves face each other in the length direction and are spaced apart and approach each other.

  According to the eighth aspect of the present invention, the pair of leaves facing each other in the length direction are separated from each other by using an actuator, and the shape of the opening formed between the leaves is changed to a target three-dimensional shape. It becomes possible to change more finely according to the shape.

  According to a ninth aspect of the present invention, there is provided a range compensator characterized in that a taper surface inclined obliquely is formed on a leaf.

  According to the ninth aspect of the invention, the energy of the radiation after passing can be changed in accordance with the passage position of the radiation with respect to the tapered surface formed on the leaf, and the radiation range matches the shape of the target. It can be set to a smoother shape.

  The invention according to claim 10 is a range compensator characterized in that the energy absorber is advanced and retracted during radiation irradiation.

  According to the tenth aspect of the present invention, the range of the radiation with respect to the target can be adjusted with higher accuracy according to the three-dimensional shape of the target by advancing and retracting the energy absorber during irradiation of the radiation.

  An eleventh aspect of the present invention is a heavy charged particle beam irradiation apparatus including a range compensator.

  According to the eleventh aspect of the present invention, by using a heavy charged particle beam irradiation apparatus provided with a range compensation device instead of the range compensation filter described in the prior art, treatment by the heavy charged particle beam irradiation apparatus is performed. Can increase the efficiency.

  As described above in detail, according to the first aspect of the invention, since the plurality of energy absorbers are individually moved independently toward the radiation path by the actuator, each energy absorber is radiated using the actuator. By moving forward and backward toward the path, the range of the radiation with respect to the target can be automatically changed for each target according to the position and shape of the target, and an irradiation region that matches the three-dimensional shape of the target can be formed. it can. Therefore, it is not necessary to manufacture or replace the range compensation filter as described in the prior art for each patient target, and to store, discard, etc., greatly reducing the time and cost required for treatment. Can do.

  In the invention according to claim 2, since the energy absorption layer is configured by arranging a plurality of leaves made of an elongated plate-like body as an energy absorber in a plate shape, each leaf constituting the energy absorption layer is used as a radiation path. By moving forward and backward separately, the shape of the opening formed between each leaf can be changed more finely, and the range of radiation with respect to the target can be adjusted more accurately according to the three-dimensional shape of the target It is possible to improve the performance of the range compensator.

  In the invention according to claim 3, since a plurality of energy absorption layers are arranged along the path of the radiation, the range of the radiation with respect to the target is adjusted more finely by moving each leaf for each energy absorption layer. And the range compensator performance can be further enhanced.

  The invention according to claim 4 is configured such that the leaf of at least one of the plurality of energy absorption layers is moved in a direction different from the leaves of the other energy absorption layers. Can be adjusted with high accuracy, and the performance of the range compensator can be further enhanced.

  In the invention according to claim 5, since the leaf of at least one of the plurality of energy absorption layers is formed with a plate thickness different from the leaf of the other energy absorption layer, the radiation is The energy of radiation after passing through the leaf can be changed between passing through a small leaf and passing through a leaf having a large thickness, and the range of the radiation with respect to the target can be adjusted with high accuracy. .

  In the invention according to claim 6, since the leaf of at least one of the plurality of energy absorption layers is made of a material having an energy absorption rate different from that of the leaves of the other energy absorption layers, , The energy of the radiation after passing through the leaf can be changed between passing through a leaf with a small energy absorption rate and passing through a leaf with a large energy absorption rate, and the range of the radiation to the target Can be adjusted with high accuracy.

  In the invention according to claim 7, since the leaf of at least one of the plurality of energy absorption layers has a plate width different from that of the other energy absorption layers, the leaf having a small plate width is formed. And a leaf having a large plate width are used in combination, the range of radiation with respect to the target can be adjusted with high accuracy in accordance with the three-dimensional shape of the target.

  According to the eighth aspect of the present invention, the energy absorbing layer is configured such that the pair of leaves are opposed to each other in the length direction so as to be separated from each other and approach each other. By using the actuators to separate and approach each other, the shape of the opening formed between each leaf can be changed more finely according to the three-dimensional shape of the target, and the radiation range to the target is highly accurate Can be adjusted.

  According to the ninth aspect of the present invention, since the tapered inclined surface is formed on the leaf, the energy of the radiation after passing is changed according to the radiation passing position with respect to the tapered surface formed on the leaf. And the range of the radiation can be set to a smoother shape that matches the shape of the target.

  Since the invention according to claim 10 is configured to advance and retract the energy absorber during irradiation of radiation, the range of radiation with respect to the target can be adjusted with higher accuracy in accordance with the shape of the target.

  Since the invention according to claim 11 is configured to use a heavy charged particle beam irradiation apparatus provided with a range compensation device instead of the range compensation filter described in the prior art, the treatment by the heavy charged particle beam irradiation apparatus is performed. Can increase the efficiency.

(First embodiment)
The case where the range compensation apparatus and heavy charged particle beam irradiation apparatus according to the first embodiment of the present invention are used in a heavy particle beam cancer treatment apparatus will be described as an example with reference to FIGS. 1 to 3. .

  FIG. 1 is a partially enlarged sectional view showing an irradiation part and a patient of the heavy ion beam cancer treatment apparatus according to the present embodiment, and FIG. 2 shows the range compensator in the direction indicated by arrows II-II in FIG. It is the front view seen. FIG. 3 is an enlarged partial perspective view showing the leaf in FIG. 1 and 2, the X direction indicates the lateral direction of the body of the patient 3, the Y direction indicates the body axis direction of the patient 3, and the Z direction indicates the axial direction (irradiation direction) of the irradiation beam 1. Yes.

  As shown in FIG. 1, the heavy ion beam cancer treatment device 11 corresponds the irradiation beam 1 to the target 4 of the patient 3 through the opening 8B formed between the metal plates 8A and 8A in substantially the same manner as in the prior art. A multi-leaf collimator device 8 for processing into the beam shape, and provided in the middle of the path of the irradiation beam 1 at a position downstream of the multi-leaf collimator device 8 to absorb the energy of the irradiation beam 1 and A range compensator 12 to be adjusted and a bed 2 on which the patient 3 lies are provided.

  Further, as shown in FIG. 2, the range compensator 12 includes an energy absorption layer 14 including a plurality of leaves 13, 13,... As energy absorbers that absorb energy of the irradiation beam 1 (see FIG. 1), Each of the leaves 13 of the energy absorption layer 14 is configured by a plurality of actuators 15, 15,... That individually advance and retract independently toward the path of the irradiation beam 1.

  Here, each leaf 13 constituting the energy absorption layer 14 is formed as a rectangular plate having a certain plate thickness by using, for example, a metal material, a plastic material or the like (see FIG. 3). The leaf 13 is, for example, a plate-like body having a width of 2 cm, a thickness of 1 cm, and a length of 40 cm. As shown in FIG. 16 rows) are arranged side by side. The actuator 15 includes, for example, a rack attached to the leaf 13, a pinion that meshes with the rack, a motor that rotationally drives the pinion, and a control mechanism that controls the rotation of the motor (none of which are shown). It is comprised including. The actuator 15 is configured to move the leaf 13 integrated with the rack in the X direction by rotationally driving the pinion using a motor and a control mechanism.

  For this reason, as shown in FIG. 2, the pair of leaves 13 and 13 opposed in the X direction are moved in the X direction so as to be separated from and approach each other by the actuator 15, thereby forming an opening 16 between the leaves 13. To do. In other words, the range compensator 12 automatically changes the opening 16 to various shapes according to the three-dimensional shape of the target 4 by individually operating the leaves 13 using the actuator 15. .

Next, the effect | action of the heavy particle beam cancer treatment apparatus 11 is demonstrated.
First, the three-dimensional shape of the target 4 of the patient 3 is measured in advance using X-ray CT, MRI or the like. Then, according to the measured shape of the target 4, each leaf 13 is individually actuated by the actuator 15 to change the shape of the opening 16. Then, as shown in FIG. 1, the irradiation beam 1 is irradiated toward the target 4 of the patient 3. The irradiation beam 1 passes through the range compensator 12 in the middle of the path. At this time, the component that passes through the opening 16 of the energy absorption layer 14 reaches deep inside the body, whereas the component that passes through each leaf 13 of the energy absorption layer 14 is absorbed by the leaf 13. Only the range becomes shallower. That is, it is possible to compensate by changing the range of the irradiation beam 1 with respect to the target 4 of the patient 3 in two stages.

  As described above, according to the present embodiment, the irradiation region (dose distribution) that matches the three-dimensional shape of the target 4 is formed by advancing and retracting each leaf 13 toward the path of the irradiation beam 1 using the actuator 15. It is possible to prevent exposure to a normal tissue in a deep part beyond the target 4 and improve the performance, reliability, and the like of the heavy ion beam cancer treatment device 11.

  In addition, according to the present embodiment, since each leaf 13 is moved using the actuator 15, the shape of the opening 16 is automatically changed appropriately for each patient 3 according to the position and shape of the target 4. can do. Therefore, it is not necessary to manufacture or replace the range compensation filter as described in the prior art for each patient 3, and to store, discard, etc., and the time and cost required for treatment can be greatly reduced.

(Second Embodiment)
Next, FIGS. 4 to 6 show a second embodiment of the present invention. In the present embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  FIG. 4 is a partial enlarged cross-sectional view showing an irradiation part and a patient of the heavy ion beam cancer treatment apparatus according to the present embodiment, and FIG. 5 shows the range compensator in the direction of arrows VV in FIG. It is the front view seen. FIG. 6 is a partial perspective view showing the leaf in FIG. 5 in an enlarged manner.

  As shown in FIG. 4, the heavy ion beam cancer treatment device 21 includes a multi-leaf collimator device 8, a range compensation device 22, and a bed 2, almost as in the first embodiment. However, the range compensator 22 used in the present embodiment includes a first energy absorbing layer 24 composed of a plurality of leaves 23, 23,... And a plurality of leaves 25, 25, as shown in FIGS. ,... Is different from that of the first embodiment in that it is constituted by the second energy absorbing layer 26 composed of.

  Here, the first energy absorption layer 24 and the second energy absorption layer 26 are stacked along the path of the irradiation beam 1 as shown in FIG. In the first energy absorbing layer 24, as shown in FIG. 5, the leaves 23 are arranged in a plurality of rows in the Y direction so as to face each other in the X direction. That is, the leaves 23 are arranged in a 16-row plate shape, for example, in a direction orthogonal to the path of the irradiation beam 1 as a pair. Further, the second energy absorption layer 26 is also arranged in a 16-row plate shape in a direction orthogonal to the path of the irradiation beam 1 as a set of two sheets. Each leaf 23 and each leaf 25 is moved independently in the X direction by an actuator 27 and an actuator 28 (see FIG. 4), respectively.

  In the present embodiment configured as described above, the first energy absorption layer 24 and the second energy absorption layer 26 are arranged along the path of the irradiation beam 1. The shape of the opening 29 and the shape of the opening 30 of the second energy absorption layer 26 can be individually changed. For this reason, it is possible to compensate by changing the range of the irradiation beam 1 with respect to the target 4 of the patient 3 in four stages at the maximum. That is, when the irradiation beam 1 passes through the openings 29 and 30, passes only through the energy absorption layer 24, and passes through only the energy absorption layer 26, it passes through both energy absorption layers 24 and 26. There are cases, and the range of the irradiation beam 1 is different in each case. Therefore, the range of the irradiation beam 1 with respect to the target 4 can be finely adjusted, and the performance, reliability, and the like of the heavy ion beam cancer treatment device 21 can be further enhanced.

(Third embodiment)
Next, FIG. 7 and FIG. 8 show a third embodiment of the present invention. In the present embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  FIG. 7 is a partial enlarged cross-sectional view showing an irradiation part and a patient of the heavy ion beam cancer treatment apparatus according to the present embodiment, and FIG. 8 shows the range compensator in the direction of arrows VIII-VIII in FIG. It is the rear view seen.

  As shown in FIG. 7, the heavy ion beam cancer treatment device 31 includes a multi-leaf collimator device 8, a range compensation device 32, and a bed 2 in substantially the same manner as in the second embodiment. As shown in FIGS. 7 and 8, the range compensator 32 includes a first energy absorption layer 34 composed of a plurality of leaves 33, 33,..., And a second energy composed of a plurality of leaves 35, 35,. The energy absorption layer 36 is laminated along the path of the irradiation beam 1.

  However, as shown in FIG. 8, the leaves 33 of the first energy absorption layer 34 are arranged in a plurality of rows (16 rows) in the Y direction so as to oppose each other in the X direction as a pair. On the other hand, the leaves 35 of the second energy absorption layer 36 are arranged in a plurality of rows (16 rows) in the X direction so as to face each other in the Y direction as a set of two sheets. This is different from the second embodiment.

  In this embodiment configured as described above, the leaf 33 of the first energy absorption layer 34 can be moved in the X direction by the actuator 37, and the leaf 35 of the second energy absorption layer 36 can be moved in the Y direction by the actuator 38. Since it can move, the openings 39 and 40 of the energy absorption layers 34 and 36 can be individually changed in the X and Y directions, respectively, and the range of the irradiation beam 1 can be adjusted more finely. Therefore, by using the energy absorbing layers 34 and 36, for example, the range of the irradiation beam 1 can be matched more closely to a crescent-shaped target 4 'having a depression at the center.

  Further, the leaf 33 of the first energy absorption layer 34 is arranged to move in the X direction, and the leaf 35 of the second energy absorption layer 36 is arranged to move in the Y direction. The actuator 37 attached to the actuator 35 and the actuator 38 attached to the leaf 35 do not interfere with each other, and the layout design of the actuators 37 and 38 can be easily performed.

(Fourth embodiment)
Next, FIG. 9 shows a fourth embodiment of the present invention. In the present embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  FIG. 9 is a partial enlarged cross-sectional view showing an irradiation part and a patient of the heavy ion beam cancer treatment apparatus according to the present embodiment. As shown in FIG. 9, the heavy ion beam cancer treatment device 41 includes a multi-leaf collimator device 8, a range compensation device 42, and a bed 2 in substantially the same manner as in the second embodiment. The range compensator 42 includes a first energy absorption layer 44 composed of a plurality of leaves 43, 43,... And a second energy composed of a plurality of leaves 45, 45,. An absorption layer 46 is stacked along the path of the irradiation beam 1. Further, by moving the leaves 43 and 45 separately and independently by the actuators 47 and 48, openings 49 and 50 are formed in the first and second energy absorption layers 44 and 46, respectively.

  However, in the range compensator 42 used in the present embodiment, the plate thickness of the leaf 45 constituting the second energy absorption layer 46 is larger than the plate thickness of the leaf 43 constituting the first energy absorption layer 44. It differs from that of the second embodiment in that it is formed.

  In the present embodiment configured as described above, the range of the irradiation beam 1 can be adjusted by using the leaf 45 having a large thickness for the portion where the shape change in the depth direction of the target 4 is large, and the target For the portion where the shape change in the depth direction of 4 is small, the range of the irradiation beam 1 can be adjusted by using the leaf 43 having a small plate thickness, so that the range of the irradiation beam 1 matches the target 4 more closely. Can be made.

(Fifth embodiment)
Next, FIG. 10 shows a fifth embodiment of the present invention. In the present embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  FIG. 10 is a partial enlarged cross-sectional view showing an irradiation part and a patient of the heavy ion beam cancer treatment apparatus according to the present embodiment. As shown in FIG. 10, the heavy ion beam cancer treatment device 51 includes a multi-leaf collimator device 8, a range compensation device 52, and a bed 2 in substantially the same manner as in the second embodiment. The range compensator 52 includes a first energy absorption layer 54 composed of a plurality of leaves 53, 53,... And a second energy composed of a plurality of leaves 55, 55,. An absorption layer 56 is stacked along the path of the irradiation beam 1. Further, by moving the leaves 53 and 55 separately and independently by the actuators 57 and 58, openings 59 and 60 are formed in the first and second energy absorption layers 54 and 56, respectively.

  However, in the range compensator 52 used in the present embodiment, the leaf 53 constituting the first energy absorption layer 54 is formed using a plastic material or the like having a relatively low energy absorption rate. The leaf 55 constituting the second energy absorption layer 56 is different from that of the second embodiment in that the leaf 55 is formed using a metal material having a relatively large energy absorption rate.

  Also in the present embodiment configured as described above, the range of the irradiation beam 1 can be adjusted using the leaf 55 having a relatively large energy absorption rate for a portion where the shape change in the depth direction of the target 4 is large. At the same time, since the range of the irradiation beam 1 can be adjusted by using the leaf 53 having a relatively small energy absorption rate for a portion where the shape change in the depth direction of the target 4 is small, the irradiation beam 1 with respect to the target 4 The range can be made more consistent, and almost the same effect as in the fourth embodiment can be obtained.

(Sixth embodiment)
Next, FIGS. 11 and 12 show a sixth embodiment of the present invention. In the present embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  FIG. 11 is a partial enlarged cross-sectional view showing an irradiation part and a patient of the heavy ion beam cancer treatment apparatus according to the present embodiment, and FIG. 12 is a partial perspective view showing the leaf in FIG. 11 in an enlarged manner. .

  As shown in FIG. 11, the heavy particle beam cancer treatment device 61 includes a multileaf collimator device 8, a range compensation device 62, and a bed 2. Further, as shown in FIG. 12, the range compensator 62 is disposed along the Y direction, with the first energy absorption layer 64 including a plurality of leaves 63, 63,... Disposed along the Y direction. The second energy absorption layer 66 composed of a plurality of leaves 65, 65,... And the third energy absorption layer 68 composed of a plurality of leaves 67, 67,. The layers are sequentially stacked along the path. Further, by moving the leaves 63, 65, and 67 independently in the Y direction by actuators (not shown), openings are formed in the first, second, and third energy absorption layers 64, 66, and 68. 69, 70, 71 are formed.

  Here, among the leaves 63, 65 and 67, the leaf width of the leaf 65 is formed smaller than the plate width of the leaves 63 and 67. Further, the leaf 63 and the leaf 67 are, for example, the plate width of the leaf 65 so that the seam along the Y direction between the leaves 63 and 63 does not coincide with the seam along the Y direction between the leaves 67 and 67. They are alternately displaced in the X direction.

  As described above, in this embodiment, the plate width of the leaf 65 constituting the second energy absorption layer 66 is smaller than the plate width of the leaves 63 and 67 constituting the first and third energy absorption layers 64 and 68. Since it is formed, the range of the irradiation beam 1 is adjusted using a leaf 65 having a small division width, that is, a small plate width, for a portion where the change in shape (depth) in the width direction of the target 4 is large. 4, the range of the irradiation beam 1 can be adjusted by using the leaves 63 and 67 having a large division width, that is, a large plate width. Thus, the range of the irradiation beam 1 can be matched more closely to the target 4.

  In addition, since the joint between the leaves 63 and 63 is shifted relative to the joint between the leaves 67 and 67, the irradiation beam 1 should pass between the leaves 67 and 67 and between the leaves 65 and 65. However, a phenomenon in which the irradiation beam 1 passes through the leaf 63 when the passing irradiation beam 1 hits the leaf 63 can be avoided, and the irradiation region of the irradiation beam 1 on the target 4 has a gentle shape close to the shape of the target 4. Can be.

(Seventh embodiment)
Next, FIG. 13 shows a seventh embodiment of the present invention. In the present embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  FIG. 13 is a partial enlarged cross-sectional view showing an irradiation part and a patient of the heavy ion beam cancer treatment apparatus according to the present embodiment. As shown in FIG. 13, the heavy particle beam cancer treatment device 81 includes a multi-leaf collimator device 8, a range compensation device 82, and the bed 2. Further, the range compensator 82 includes a first energy absorption layer 84 composed of a plurality of leaves 83, 83,... Arranged along the X direction, and a plurality of leaves 85, 85 arranged along the Y direction. ,..., A second energy absorption layer 86 composed of a plurality of leaves 87, 87,... Disposed along the X direction, and a plurality of energy absorption layers 88 disposed along the Y direction. A fourth energy absorbing layer 90 made of leaves 89, 89,... Is sequentially stacked along the path of the irradiation beam 1.

  Further, by moving the leaves 83, 85, 87, 89 independently using the actuators 91, 92, etc., the first, second, third, and fourth energy absorbing layers 84, 86, 88, In 90, openings 93, 94, 95, and 96 are formed. Further, the range compensator 82 including the energy absorbing layers 84, 86, 88, 90 and the actuators 91, 92 is arranged on the upstream side of the irradiation beam 1 with respect to the multi-leaf collimator device 8.

  In the present embodiment configured as described above, during irradiation of the irradiation beam 1, a part or all of the leaves 83, 85, 87, 89 are advanced and retreated toward the path of the irradiation beam 1 based on a program prepared in advance. By doing so, the irradiation amount of the irradiation beam 1 in a specific range that passes through the range compensator 82 can be changed during irradiation of the irradiation beam 1. As a result, the range of the irradiation beam 1 can be matched more closely to the target 4. For example, the shape of the bottom of the range of the irradiation beam 1 that is stepped in FIG. 13 may be a gentle continuous curve. Further, the range of the irradiation beam 1 can be finely adjusted by compensating for the shortage of the number of layers (number) of the leaves 83, 85, 87, and 89. In addition, since it is not necessary to replace the range compensator 82 for each patient 3, the range compensator 82 is located downstream of the irradiation beam 1 from the multi-leaf collimator 8 as in the prior art, that is, at a place where it can be easily replaced. There is no need to arrange the layout, and the layout design of the range compensator 82 can be easily performed.

(Eighth embodiment)
Next, FIG. 14 shows an eighth embodiment of the present invention. In the present embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  FIG. 14 is a partial enlarged cross-sectional view showing an irradiation part and a patient of the heavy ion beam cancer treatment apparatus according to the present embodiment. As shown in FIG. 14, the heavy ion beam cancer treatment apparatus 101 includes a multi-leaf collimator apparatus 8, a range compensation apparatus 102, and a bed 2 in substantially the same manner as in the second embodiment. The range compensator 102 includes a first energy absorption layer 104 composed of a plurality of leaves 103, 103,... And a second energy composed of a plurality of leaves 105, 105,. An absorption layer 106 is stacked along the path of the irradiation beam 1. Further, by moving the leaves 103 and 105 separately and independently by the actuators 107 and 108, openings 109 and 110 are formed in the first and second energy absorption layers 104 and 106, respectively.

  However, the range compensator 102 used in the present embodiment is the second point in that the tip sides of the leaves 103 and 105 located on the openings 109 and 110 side are formed as tapered surfaces 103A and 105A that are inclined obliquely. This is different from that of the embodiment.

  In the present embodiment configured as described above, since the distal ends of the leaves 103 and 105 are formed as the tapered surfaces 103A and 105A, even if the number of disposed energy absorbing layers 104 and 106 (number of layers) is reduced, The range of the irradiation beam 1 can be set to a smoother shape that matches the shape of the target 4 by the tapered surfaces 103A and 105A, and the performance of the range compensator 102 can be further enhanced.

  In the first embodiment, the range compensator 12 is described as an example of a configuration in which the range compensator 12 is fixedly attached to the heavy ion beam cancer treatment apparatus 11, but the present invention is not limited to this. . For example, a mechanism for rotating the range compensator 12 as indicated by an arrow A shown in FIG. 1 may be provided. In this case, the range of the irradiation beam 1 with respect to the target 4 can be adjusted more finely. The same applies to the second to eighth embodiments.

  In the first embodiment, the range compensator 12 has been described as an example of the configuration in which the range compensator 12 is disposed on the downstream side of the irradiation beam 1 with respect to the multi-leaf collimator 8, but the present invention is not limited to this. For example, the range compensation device 12 may be arranged upstream of the multi-leaf collimator device 8 with respect to the multi-leaf collimator device 8 as in the seventh embodiment. The same applies to the second to sixth and eighth embodiments.

  In the seventh embodiment, the case where the range compensator 82 is configured by stacking four energy absorption layers 84, 86, 88, and 90 has been described as an example. For example, five or more layers are stacked. Thus, the range compensator 82 may be configured.

  Furthermore, in the first embodiment, the case where a rack, a pinion, and a motor are used as the actuator 15 has been described as an example. However, the present invention is not limited to this, and for example, a cylinder that can expand and contract in the X direction or the Y direction. The actuator may be constituted by a linear motor or the like. Further, a belt, a pulley, and a motor may be used in combination, or a screw, a screw, and a motor may be used in combination. Further, the position of each leaf can be detected by directly attaching the leaf to the leaf or by attaching an encoder to the cylinder or motor and counting pulses emitted from the encoder. As a guide mechanism (not shown) that supports the movement of the leaf, a ball linear bearing may be used, or a guide member that slidably supports the leaf may be used, and the guide mechanism is not particularly limited. The same applies to the second to eighth embodiments.

  Furthermore, in the first embodiment, as shown in FIG. 4, as an example, the first energy absorption layer 24 and the second energy absorption layer 26 are configured to abut each other (surface contact). However, the present invention is not limited to this, and for example, the first energy absorption layer 24 and the second energy absorption layer 26 may be arranged at intervals with respect to the irradiation direction of the irradiation beam 1. Good. The same applies to the second to eighth embodiments.

  In the first embodiment, as shown in FIG. 6, the leaves 23 and 25 are brought into close contact with each other so that there is no gap between the adjacent leaves 23 and 23, between the leaves 25 and 25, and between the leaves 23 and 25. However, the present invention is not limited to this. For example, the present invention is not limited to this, for example, between adjacent leaves 23 and 23, between leaves 25 and 25, and between leaves 23 and 25. A configuration in which a concave groove is provided along the X-axis direction on one opposing surface (contact surface), a convex portion is provided on the other opposing surface (contact surface), and the convex portion is slidably fitted into the concave groove. It is good. The same applies to the second to eighth embodiments.

  In the third embodiment, the first energy absorption layer 34 and the second energy absorption layer 36 are stacked so that the advance / retreat direction of the leaf 33 and the advance / retreat direction of the leaf 35 are orthogonal to each other by 90 degrees. However, for example, the advancing / retreating direction of the leaf 33 and the advancing / retreating direction of the leaf 35 may intersect at an angle other than 90 degrees (for example, 60 degrees or 30 degrees).

  Furthermore, in the first embodiment, the case where a plurality of leaves 13 are used as an energy absorber has been described as an example. However, the present invention is not limited to this, and for example, a plurality of leaves 13 are integrally configured. It can also be used as a single leaf. The same applies to the second to eighth embodiments.

  In the second embodiment, the case where the openings 29 and 30 are formed using all the energy absorption layers 24 and 26 has been described as an example. However, the present invention is not limited to this, and for example, irradiation conditions Accordingly, only the necessary energy absorption layer may be moved to form the opening 29 or the opening 30. The same applies to the third to eighth embodiments.

  Furthermore, in the first embodiment, the case where the two leaves 13 and 13 are arranged side by side for each row of the energy absorption layer 14 has been described as an example, but the present invention is not limited to this. Instead, for example, one leaf may be provided for each row of the energy absorption layer 14, or three or more leaves may be provided. The same applies to the second to eighth embodiments.

  Further, in the first embodiment, the case where the energy absorbing layer 14 is configured by arranging 16 rows of the leaves 13 is described as an example. However, the present invention is not limited thereto, and for example, 17 or more rows of leaves are arranged. It may be 15 columns or less. The same applies to the second to eighth embodiments.

It is a partial expanded sectional view which shows the irradiation part and patient of the heavy ion beam cancer treatment apparatus which concerns on the 1st Embodiment of this invention. It is the front view which looked at the range compensation apparatus from the arrow II-II direction in FIG. It is a fragmentary perspective view which expands and shows the leaf in FIG. It is a partial expanded sectional view which shows the irradiation part and patient of the heavy particle beam cancer treatment apparatus which concerns on the 2nd Embodiment of this invention. It is the front view which looked at the range compensation apparatus from the arrow VV direction in FIG. It is a fragmentary perspective view which expands and shows the leaf in FIG. It is a partial expanded sectional view which shows the irradiation part and patient of the heavy particle beam cancer treatment apparatus which concerns on the 3rd Embodiment of this invention. It is the rear view which looked at the range compensation apparatus from the arrow VIII-VIII direction in FIG. It is a partial expanded sectional view which shows the irradiation part and patient of the heavy particle beam cancer treatment apparatus which concerns on the 4th Embodiment of this invention. It is the elements on larger scale which show the irradiation part and patient of the heavy particle beam cancer treatment apparatus which concerns on the 5th Embodiment of this invention. It is a partial expanded sectional view which shows the irradiation part and patient of the heavy particle beam cancer treatment apparatus which concerns on the 6th Embodiment of this invention. It is a fragmentary perspective view which expands and shows the leaf in FIG. It is the elements on larger scale which show the irradiation part and patient of a heavy particle beam cancer treatment apparatus concerning a 7th embodiment of the present invention. It is the elements on larger scale which show the irradiation part and patient of the heavy particle beam cancer treatment apparatus which concerns on the 8th Embodiment of this invention. It is the schematic which shows the whole structure of the heavy particle beam cancer treatment apparatus by a prior art. It is the elements on larger scale which show the irradiation part and patient of the heavy particle beam cancer treatment apparatus in FIG.

Explanation of symbols

1 Irradiation beam (radiation)
3 patients 4, 4 'target 11, 21, 31, 41, 51, 61, 81, 101 Heavy particle beam cancer treatment device (heavy charged particle beam irradiation device)
12, 22, 32, 42, 52, 62, 82, 102 Range compensator 13, 23, 25, 33, 35, 43, 45, 53, 55, 63, 65, 67, 83, 85, 87, 89 , 103, 105 Leaf (energy absorber)
14 Energy absorbing layer 15, 27, 28, 37, 38, 47, 48, 57, 58, 91, 92, 107, 108 Actuator 24, 34, 44, 54, 64, 84, 104 First energy absorbing layer 26 , 36, 46, 56, 66, 86, 106 Second energy absorption layer 68, 88 Third energy absorption layer 90 Fourth energy absorption layer

Claims (11)

In the range compensation apparatus that is provided in the middle of the path of radiation irradiated from the radiation source toward the target, absorbs the energy of the radiation, and adjusts the range of the radiation with respect to the target.
A range compensator comprising: a plurality of energy absorbers that absorb the energy of the radiation; and an actuator that moves the energy absorbers so as to be independently advanced and retracted toward the radiation path.   2. The range compensator according to claim 1, wherein the energy absorber is a leaf made of an elongated plate-like body, and an energy absorption layer is configured by arranging the leaves in a plurality of rows in a plate shape. .   The range compensator according to claim 2, wherein a plurality of the energy absorption layers are arranged along the path of the radiation.   4. The range compensator according to claim 3, wherein a leaf of at least one of the plurality of energy absorption layers is moved in a direction different from a leaf of another energy absorption layer.   5. The leaf of at least one of the plurality of energy absorption layers is formed with a plate thickness different from that of the other energy absorption layer. 5. Range compensator.   The leaf of at least any one of the plurality of energy absorption layers is formed of a material having an energy absorption rate different from that of the leaves of other energy absorption layers. The range compensator according to any one of 5.   The leaf of at least one energy absorption layer among the plurality of energy absorption layers is formed with a plate width different from the leaves of other energy absorption layers. The range compensator according to item 1.   8. The energy absorbing layer according to claim 2, wherein a pair of leaves are arranged to be spaced apart from each other and approach each other in a length direction for each row. 9. Range compensator.   The range compensation device according to any one of claims 2 to 8, wherein the leaf is formed with an inclined tapered surface.   The range compensator according to any one of claims 1 to 9, wherein the energy absorber is configured to advance and retract during irradiation of the radiation. A heavy charged particle beam irradiation apparatus comprising the range compensator according to any one of claims 1 to 10.

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