JP2017038773A - Irradiation particle beam control apparatus, charged particle beam irradiation system, and irradiation particle beam control method - Google Patents

Abstract

In particle beam cancer treatment, it is possible to irradiate a target portion while suppressing irradiation to a healthy tissue / important organ other than a tumor which is a target portion of irradiation. An irradiation particle beam control apparatus according to an embodiment of the present invention includes two first planes that generate a magnetic field that is opposed to each other with a path of the irradiation particle beam interposed therebetween and bends the irradiation particle beam in a direction in which the irradiation particle beam is diffused from an orbital axis. The inner diffusion electromagnets 111a and 111b and the two first in-plane diffusion electromagnets 111a and 111b in the moving direction of the irradiation particle beam are opposed to each other across the irradiation particle beam passage in the first plane. Two first in-plane converging electromagnets 112a and 112b that generate a magnetic field that bends the irradiation particle beam bent by the diffusion electromagnets 111a and 111b toward the orbital axis A direction, and two in the first plane The diffusion electromagnets 111a and 111b and the two first in-plane converging electromagnets 112a and 112b are supported. [Selection] Figure 2

Description

  Embodiments described herein relate generally to an irradiation particle beam control apparatus that controls an irradiation particle beam to irradiate an irradiation object, a charged particle beam irradiation system including the irradiation particle beam control apparatus, and an irradiation particle beam control method.

  In cancer treatment devices using charged particle beams (particle beam cancer treatment devices), it is generally necessary to damage only the tumor part when the charged particle beam accelerated by the accelerator gives a certain dose to the tumor part. There is. For this purpose, healthy tissue and important organs by the particle beam and secondary particles in and around the path of the particle beam until the particle beam reaches the tumor site and after the particle beam penetrates the tumor site ( It is important to reduce the dose given to healthy tissues and important organs.

  When the dose given to healthy tissues / important organs other than the tumor reaches a certain level, no further dose can be applied to the site, and particle beam irradiation cannot be performed. In particular, this effect becomes remarkable when irradiation is performed from only one direction. To reduce this effect, there are methods using multi-gate irradiation and a rotating gantry (Patent Documents 1 to 3).

FIG. 14 is a perspective view showing the configuration and operation of a conventional irradiation particle beam control apparatus. Charged particles used in a cancer treatment apparatus using a charged particle beam are irradiated with a diffusion electromagnet 7 so as to spread from one point of the charged particle beam exit of the accelerator to the tumor part or to scan the tumor part. Is irradiated. In this case, in the case of irradiation from one direction (single gate irradiation), the number of charged particle beams passing per 1 cm ² is larger than that in the tumor part. For this reason, the dose imparted to the healthy tissue / important organ near the body surface where the charged particle beam is incident tends to increase, and this may limit the dose to the tumor site.

  On the other hand, intensity-modulated radiation therapy (IMRT) that performs incidence from multiple directions can reduce the effect of radiation on healthy tissues and vital organs near the body surface, and thus more effectively against the tumor part. High dose can be given safely.

JP 2013-215442 A JP 2013-106981 A Japanese Patent No. 4936924

  In the above-mentioned particle beam cancer treatment apparatus capable of performing intensity-modulated radiation therapy that performs incidence from multiple directions, preparation of an irradiation port for performing multi-port irradiation or irradiation with a rotating gantry, enlargement of equipment, dynamic Necessity of equipment was an issue.

  In multi-gate irradiation, when preparing horizontal and vertical irradiation ports, it is necessary to transport charged particles to the respective irradiation ports. In order to transport the charged particles, a transport cavity, an electromagnet, and a space for installing these are required, which increases the construction cost.

  In addition, since the rotating gantry is an irradiation port provided with a rotating mechanism that can rotate around the patient, the size of the device increases. In addition, since it is a dynamic device, the accuracy of the irradiation position is lower than that of a static mechanism.

  Embodiments of the present invention have been made to solve the above-described problems, and in particle beam cancer treatment, while suppressing irradiation to healthy tissues and important organs other than tumors that are the target part of irradiation, The purpose is to enable irradiation of the target part.

  In order to achieve the above object, the present embodiment is an irradiation particle beam control apparatus for controlling an irradiation particle beam having a charge taken out along one orbital axis for irradiating an irradiation object, Two first in-plane diffusion electromagnets that generate a magnetic field that is opposed to each other across a particle beam path and bends the irradiation particle beam in a direction in which the irradiation particle beam diffuses from the orbital axis, and the movement direction of the irradiation particle beam. Two irradiation electromagnets arranged downstream of the first in-plane diffusion electromagnet, facing each other across the irradiation particle beam passage, and the irradiation particle beams bent by the first in-plane diffusion electromagnet are directed in the orbital axis direction. Two first in-plane converging electromagnets that generate a magnetic field that bends in a converging direction; a support unit that supports the two first in-plane diffusion electromagnets and the two first in-plane converging electromagnets; Prepare The features.

  Further, the present embodiment includes a deflecting electromagnet that forms a magnetic field for deflection in a circulating path of charged particles, a high-frequency acceleration cavity that imparts energy to the charged particles, and one orbital axis with the charged particles as an irradiation particle beam A charged particle beam irradiation system comprising: an accelerator having a beam emitting section that is taken out along an irradiation particle; and an irradiation particle beam control device that controls the irradiation particle beam to irradiate the irradiation target. Includes two first in-plane diffusion electromagnets that generate a magnetic field that is opposed to each other across the path of the irradiation particle beam and that bends the irradiation particle beam in a direction of diffusing from the orbital axis, and movement of the irradiation particle beam Before being bent by the first in-plane diffusing electromagnet, arranged downstream of the two first in-plane diffusing electromagnets and facing each other across the irradiation particle beam passage. Two first in-plane converging electromagnets for generating a magnetic field that bends the irradiated particle beam in a direction to converge in the orbital axis direction, the two first in-plane converging electromagnets, and the two first in-plane converging electromagnets And a support part for supporting

  Further, the present embodiment is an irradiation particle beam control method for controlling an irradiation particle beam in which charged particles accelerated for irradiating an irradiation object are taken out along one orbital axis, and two first planes An inner diffusion electromagnet diffuses the irradiated particle beam from the orbital axis, and after the first plane diffusion step, two first in-plane converging electromagnets move to the first plane diffusion step. A first plane converging step for converging the irradiated particle beam diffused in step 1 in the orbital axis direction.

  According to the embodiment of the present invention, in particle beam cancer treatment, it is possible to irradiate a target portion while suppressing irradiation to a healthy tissue / an important organ other than a tumor that is a target portion of irradiation.

It is a block diagram which shows the structure of the charged particle beam irradiation system which concerns on 1st Embodiment. It is a perspective view which shows the structure and effect | action of an irradiation particle beam control apparatus which concern on 1st Embodiment. It is a perspective view which shows the effect | action of the irradiation particle beam control apparatus which concerns on 1st Embodiment, (a) is one polarity, (b) is the case of the other polarity. It is a flowchart which shows the procedure of the charged particle beam irradiation method which concerns on 1st Embodiment. It is a conceptual graph for demonstrating the effect of the irradiation particle beam control apparatus which concerns on 1st Embodiment. It is a perspective view which shows the structure and effect | action of an irradiation particle beam control apparatus which concern on 2nd Embodiment. It is a conceptual diagram which shows the effect | action and effect of the irradiation particle beam control apparatus which concern on 2nd Embodiment, (a) is the case of 1st Embodiment, (b) is the case of 2nd Embodiment. It is a perspective view which shows the structure and effect | action of an irradiation particle beam control apparatus which concern on 3rd Embodiment. It is a flowchart which shows the procedure of the charged particle beam irradiation method which concerns on 3rd Embodiment. It is a conceptual diagram which shows the effect of the charged particle beam irradiation method which concerns on 3rd Embodiment. It is a conceptual diagram which shows another example of the effect of the charged particle beam irradiation method which concerns on 3rd Embodiment. It is a conceptual diagram which shows the structure of the charged particle beam irradiation system which concerns on 4th Embodiment. It is a conceptual diagram which shows the structure of the modification of the charged particle beam irradiation system which concerns on 4th Embodiment. It is a perspective view which shows the structure and effect | action of the conventional irradiation particle beam control apparatus.

  Hereinafter, an irradiation particle beam control apparatus, a charged particle beam irradiation system, and an irradiation particle beam control method will be described with reference to the drawings. Here, the same or similar parts are denoted by common reference numerals, and redundant description is omitted.

[First Embodiment]
FIG. 1 is a block diagram showing a configuration of a charged particle beam irradiation system according to the first embodiment. The charged particle beam irradiation system 200 includes an accelerator 10 and an irradiation particle beam control device 100. The accelerator 10 is a synchrotron. The accelerator 10 includes an orbiting beam vacuum vessel 11 around which accelerated particles to be accelerated, a deflecting electromagnet 12, an incident electromagnet 13 for introducing charged particles from a source of charged particles to be accelerated particles, and a high-frequency acceleration cavity. Part 14, an extraction electromagnet 15 for taking out accelerated particles, a circular beam converging quadrupole electromagnet 16 and a quadrupole electromagnet power supply 16a.

  The deflecting electromagnet 12 forms a magnetic field in a direction perpendicular to the traveling plane of the accelerating particles in the circular beam vacuum vessel 11. The circular beam vacuum vessel 11 surrounded by the deflecting electromagnet 12 has a curvature, and the direction of the acceleration particles is changed in this portion. The strength of the magnetic field is increased according to the energy increase of the accelerated particles so that the traveling direction of the accelerated particles always follows this curvature. Specifically, the current supplied from the deflection electromagnet power source 12a, which is the power source of the current of a coil (not shown) of the deflection electromagnet 12, is increased.

  The high-frequency accelerating cavity 14 is a part that supplies energy to so-called high-frequency accelerating cavities, and has members such as a vacuum duct that forms the cavity and a housing outside the vacuum duct. The energy is supplied by increasing the frequency of the high frequency by the high frequency generator 14a.

  As an apparatus for supplying charged particles to be accelerated to the orbiting beam vacuum vessel 11, the accelerator 10 serves as an ion source 17a, an incident accelerator 17b for accelerating charged particles from the ion source 17a, and a path for charged particles. An incident vacuum container 17 is provided.

  Further, the accelerator 10 has a beam emitting unit 18 as a device for extracting particles accelerated from the circular beam vacuum vessel 11 as an irradiation particle beam. The charged particles taken out from the circular beam vacuum vessel 11 by the beam emitting unit 18 in order to irradiate the irradiation object 1 are hereinafter referred to as irradiation particle beams. An irradiation particle beam control device 100 that controls the trajectory of the irradiation particle beam is provided at the exit of the beam emitting unit 18.

  FIG. 2 is a perspective view showing the configuration and operation of the irradiation particle beam control apparatus according to the first embodiment. The irradiation particle beam control apparatus 100 supports the first in-plane diffusion electromagnet 111 and the first in-plane convergence electromagnet 112, and the first in-plane diffusion electromagnet 111 and the first in-plane convergence electromagnet 112 in a stationary manner (not shown). It has a support part.

  The first in-plane diffusion electromagnet 111 includes a first in-plane diffusion electromagnet 111a and a first in-plane diffusion electromagnet 111b. The first in-plane diffusing electromagnet 111a and the first in-plane diffusing electromagnet 111b are arranged to face each other with an interval in parallel with the orbital axis A of the irradiation particle beam interposed therebetween. Here, the trajectory axis refers to the trajectory of the irradiated particle beam that is emitted from the beam emitting unit 18 and that is substantially in the same direction and is substantially on the same straight line.

  The first in-plane diffusion electromagnet 111a and the first in-plane diffusion electromagnet 111b together form a magnetic flux that connects the first in-plane diffusion electromagnet 111a and the first in-plane diffusion electromagnet 111b. . The first in-plane diffusion electromagnet 111a and the first in-plane diffusion electromagnet 111b are configured to be able to change the magnitude and polarity of the magnetic flux. The coil of the first in-plane diffusion electromagnet 111a and the coil of the first in-plane diffusion electromagnet 111b may be independent from each other or may be connected in series with each other. The electromagnet may be a superconducting electromagnet.

  Similarly, the first in-plane converging electromagnet 112a and the first in-plane converging electromagnet 112b are coupled to each other to form a magnetic flux connecting the first in-plane converging electromagnet 112a and the first in-plane converging electromagnet 112b. Form. The first in-plane converging electromagnet 112a and the first in-plane converging electromagnet 112b are configured to be able to change the magnitude and polarity of the magnetic flux.

  The current direction of the set of first in-plane diffusion electromagnet 111a and first in-plane diffusion electromagnet 111b and the direction of current in the set of first in-plane converging electromagnet 112a and first in-plane convergence electromagnet 112b , They are synchronized so that they are in opposite directions.

  FIG. 3 is a perspective view illustrating the operation of the irradiation particle beam control apparatus, where (a) shows one polarity and (b) shows the other polarity. That is, (a) shows the first in-plane diffusion electromagnet 111a and the first in-plane diffusion so that the magnetic flux vector B1 is in the direction from the first in-plane diffusion electromagnet 111a to the first in-plane diffusion electromagnet 111b. This is a case where a current flows through the electromagnet 111b. (B) shows the first in-plane diffusion electromagnet 111a and the first in-plane diffusion so that the magnetic flux vector B2 is in the direction from the first in-plane converging electromagnet 111b to the first in-plane diffusion electromagnet 111a. This is a case where a current flows through the electromagnet 111b.

A force vector F acting on a Ne ⁺ charged particle moving in the magnetic flux vector B at a velocity vector v is given by the following equation (1).
F = Ne · v × B (1)
Here, x is an outer product of vectors.

  Therefore, as shown in (a), the force vector F in the x direction acts on the positive charged particles that advance by v in the z direction within the magnetic field of the magnetic flux vector B1 in the -y direction. For this reason, the charged particle does not go to the point P0 that has traveled straight on the straight line L0 that is the incident locus axis, but deviates from the straight line L0 and moves in the direction of the point P1 on the straight line L1 that extends vertically upward through the point P0. The That is, the charged particles move while bending in a plane (first plane) including the straight lines L0 and L1. If the density of the magnetic flux vector B1 is constant, the locus is on an arc.

  On the other hand, as shown in (b), a force vector F acts in the −x direction on the charged particles traveling at v in the z direction within the magnetic field of the magnetic flux vector B2 in the y direction. For this reason, the charged particle does not go to the point P0 that has traveled straight on the straight line L0 that is the incident locus axis, but deviates from the straight line L0 and moves in the direction of the point P2 on the straight line L1 that extends vertically downward through the point P0. The That is, it moves in a direction opposite to the case of (a) in the first plane while turning off the straight line L0 that is the locus axis.

  As described above, the case of having a positive charge such as a proton beam or a heavy particle beam has been described. However, the case of having a negative charge such as an electron beam is reversed, but the effect is the same.

  The magnetic flux between the first in-plane diffusion electromagnet 111a and the first in-plane diffusion electromagnet 111b shown in FIG. 2 periodically repeats the change in the direction of the magnetic flux vector B1 and the direction of the magnetic flux vector B2 shown in FIG. . It is better that the periodic repetition is not fixed in a certain direction, for example, a change like a sine wave is desirable.

  On the other hand, in the first in-plane converging electromagnet 112a and the first in-plane converging electromagnet 112b shown in FIG. 2, the magnetic flux between the first in-plane converging electromagnet 112a and the first in-plane converging electromagnet 112b is the first. A current is generated so as to generate a magnetic flux in a direction opposite to the magnetic flux between the in-plane diffusion electromagnet 111a and the first in-plane diffusion electromagnet 111b.

  That is, for example, when the first in-plane diffusion electromagnet 111 is in the state of FIG. 3A, the first in-plane converging electromagnet 112 is in the state of (b). Similarly, when the first in-plane diffusion electromagnet 111 is in the state of FIG. 3B, the first in-plane converging electromagnet 112 is in the state of (a).

  As a result, the charged particles moving in the first in-plane diffusion electromagnet 111 move in the first in-plane converging electromagnet 112 after bending from the straight line L0 which is the locus axis of incidence and bending in the + x direction. When it turns, it turns in the opposite direction, that is, it turns in the direction approaching the straight line L0 which is the locus axis which has entered. The current that generates the magnetic flux can be controlled so that the convergence position becomes the target portion 5 of the irradiation target 1. Hereinafter, the fact that the charged particle deviates from the orbital axis L0 is referred to as diffusion. Further, returning to the direction of the orbital axis L0 means convergence.

  For example, when an important organ in a healthy state or a portion thereof (healthy / important organ) exists in the direction shown in FIG. 3B, by excluding this direction from the sweep range, It can prevent irradiation of healthy and important organs. The exclusion from the sweep area can also be made by narrowing the width of the sweep. Alternatively, it is possible to exclude even the middle range by jumping from the middle direction to another direction. In this way, it is possible to reach the target portion 5 from a route other than the central portion while the target portion 5 exists in front of the center.

  FIG. 4 is a flowchart showing the procedure of the charged particle beam irradiation method according to the first embodiment. First, charged particles are accelerated by the accelerator 10 (step S01). Specifically, the charged particles supplied from the ion source 17a flow into the circulating beam vacuum vessel 11 via the incident electromagnet 13 via the incident accelerator 17b. In the circular beam vacuum vessel 11, while being energized by the high-frequency acceleration cavity 14, the deflection electromagnet 12 bends along the circular beam vacuum vessel 11, and the circular beam converging quadrupole electromagnet 16 turns the circular axis. It is accelerated while converging at the center. Next, the emitted electromagnet 15 takes out charged particles as an irradiation particle beam (step S02).

  After the irradiation particle beam is taken out, the first in-plane diffusion electromagnet 111 diffuses the irradiation particle beam (step S03). The first in-plane converging electromagnet 112 converges the diffused irradiation particle beam in synchronization with the first in-plane diffusion electromagnet 111 (step S04).

  FIG. 5 is a conceptual graph for explaining the effect of the irradiation particle beam control apparatus according to the first embodiment. The horizontal axis is the position from the skin surface. The vertical axis represents the irradiation dose of the irradiation particle beam at each position.

  A curve B indicated by a broken line is an irradiation dose distribution in the case of the conventional method. A curved line A indicated by a solid line is an irradiation dose distribution in the case of the irradiation particle beam control method according to the present embodiment. As shown in FIG. 5, in the case of the conventional method, the irradiation dose level is gently distributed in the path from the surface of the skin to the target portion 5 and also in the range far behind the target portion 5.

  On the other hand, in the present embodiment, the irradiation level is finally secured in the target portion 5, but the irradiation level is kept low in the route to the target portion 5. Moreover, since the irradiation particle beam control apparatus 100 in this embodiment is comprised only from a static element and does not use a dynamic apparatus, it can irradiate with sufficient precision.

  As described above, according to the present embodiment, in the particle beam cancer treatment, the target portion is suppressed while suppressing irradiation to a healthy tissue / important organ other than the tumor that is the target portion of irradiation without requiring a large-scale apparatus. Irradiation is possible.

[Second Embodiment]
FIG. 6 is a perspective view showing the configuration and operation of the irradiation particle beam control apparatus according to the second embodiment. The first in-plane diffusion electromagnet 111 and the first in-plane converging electromagnet 112 are supported by the support portion 130. The support unit 130 includes an electromagnet mounting bar 131 and a support plate 132.

  Two electromagnet mounting bars 131 extending in a direction perpendicular to the track axis are attached to the upper and lower portions of the first in-plane diffusion electromagnet 111 and the first in-plane converging electromagnet 112, respectively. Both ends of the electromagnet mounting bar 131 are connected to the support plate 132, respectively.

  The support portion 130 is configured to be rotatable about a straight line L0 that is a locus axis. The configuration of the electromagnet mounting bar 131 and the support plate 132 is such that the first in-plane diffusion electromagnet 111 and the first in-plane convergence electromagnet 112 and the first in-plane convergence electromagnet 112 are self-weighted. Other configurations may be used as long as the load is reliably transmitted and can be rotated.

  FIG. 7 is a conceptual diagram showing the operation and effect of the irradiation particle beam control apparatus according to the second embodiment. (A) is the case of the first embodiment, and (b) is the case of the second embodiment. It is. Each shows the trajectory of the irradiation particle beam passing through the surface of the irradiation target 1, that is, the surface of the skin in the case of a patient.

  In the case of the first embodiment, as shown in FIG. 7A, a sweep is performed between x1 and x2 on a curve where the first plane and the irradiation target 1 intersect. In the second embodiment, as shown in FIG. 17B, the entire trajectory is such that the trajectory that sweeps around the point P rotates while sweeping between x1 and x2. Here, the point P is an intersection of the straight line L0 that is the trajectory axis and the surface of the irradiation target 1.

  As described above, the passing points on the surface of the irradiation target 1 of the irradiation particle beam are dispersed in a range within the circle C which is the locus of the points x1 and x2. As a result, it is possible to irradiate the target portion 5 while suppressing irradiation to a healthy tissue / important organ other than the tumor, which is the target portion 5 of irradiation, without requiring a large-scale device.

[Third Embodiment]
FIG. 8 is a perspective view showing the configuration and operation of the irradiation particle beam control apparatus according to the third embodiment. This embodiment is a modification of the first embodiment. The irradiation particle beam control apparatus 100 according to the third embodiment further includes a second in-plane diffusion electromagnet 121 and a second in-plane convergence electromagnet 122 provided downstream of the first in-plane convergence electromagnet 112.

  The second in-plane diffusion electromagnet 121 includes a second in-plane diffusion electromagnet 121a and a second in-plane diffusion electromagnet 121b. The second in-plane diffusion electromagnet 121a and the second in-plane diffusion electromagnet 121b are 90 around the straight line L0 that is the locus axis with respect to the first in-plane convergence electromagnet 112a and the first in-plane convergence electromagnet 112b. It is fixed in the rotated direction.

  The second in-plane converging electromagnet 122 is provided downstream of the second in-plane diffusion electromagnet 121. The second in-plane convergence electromagnet 122 includes a second in-plane convergence electromagnet 122a and a second in-plane convergence electromagnet 122b. The second in-plane converging electromagnet 122a and the second in-plane converging electromagnet 122b are fixed in the same direction as the second in-plane diffusion electromagnet 121a and the second in-plane diffusion electromagnet 121b.

  Therefore, the magnetic flux between the second in-plane diffusion electromagnet 121a and the second in-plane diffusion electromagnet 121b is the same as the magnetic flux between the first in-plane convergence electromagnet 112a and the first in-plane convergence electromagnet 112b. The directions are orthogonal to each other about the straight line L0 as the locus axis. Therefore, if the irradiation particle beam flows in the direction of the straight line L0 that is the locus axis, the direction is bent in the second plane that is orthogonal to the first plane and the straight line L0 that is the locus axis. The magnetic flux formed by the second in-plane converging electromagnet 122a and the second in-plane converging electromagnet 122b in the second plane is formed by the second in-plane diffusion electromagnet 121a and the second in-plane diffusion electromagnet 121b. The magnitude and direction of the current flowing through the coils of the respective electromagnets are adjusted so that the magnetic flux is formed in the opposite direction with respect to the first plane and the straight line L0 that is the locus axis.

FIG. 9 is a flowchart showing the procedure of the charged particle beam irradiation method according to the third embodiment. Steps S01 to S14 are the same as those in the first embodiment. Step S03,
In parallel with step S14, the second in-plane diffusion electromagnet 121 diffuses the irradiated particle beam (step S15). Subsequent to step S15, the second in-plane converging electromagnet 122 converges the irradiation particle beam in synchronization with the second in-plane diffusion electromagnet 121 (step S16).

  The change in magnetic flux by the second in-plane diffusion electromagnet 121 and the second in-plane converging electromagnet 122, and the resulting sweep period substantially parallel to the second plane is determined by the first in-plane diffusion electromagnet 111 and the first in-plane convergence. It is sufficiently longer than the sweep cycle in the first plane by the electromagnet 112.

  FIG. 10 is a conceptual diagram showing the effect of the charged particle beam irradiation method according to the third embodiment. The locus | trajectory of the place where an irradiation particle beam passes the surface of the irradiation object 1 is shown. While being swept between x1 and x2 in the first plane by the first in-plane diffusion electromagnet 111 and the first in-plane converging electromagnet 112, the second in-plane diffusion electromagnet 121 and the second in a longer cycle. The in-plane converging electromagnet 122 sweeps between y1 and y2 in a plane substantially parallel to the second plane.

  As described above, the temporal change period of the magnetic flux by the first in-plane diffusion electromagnet 111 and the first in-plane convergence electromagnet 112 and the magnetic flux by the second in-plane diffusion electromagnet 121 and the second in-plane convergence electromagnet 122. If the period of time change of is distant, the surface of the irradiation target 1 can be spread almost uniformly in the (x1-x2) × (y1-y2) plane.

  FIG. 11 is a conceptual diagram showing another example of the effect of the charged particle beam irradiation method according to the third embodiment. Here, a region R surrounded by a broken line is a region excluded from the sweep range through which the irradiation particle beam passes. For example, the required irradiation direction exists from the maximum value of the acceleration energy of the charged particle accelerator 10 and the position of the target portion 5 in the irradiation target 1. However, when the irradiation is performed as it is, there are cases where healthy and important organs exist in the path to the target portion 5. Even in such a case, as shown in FIG. 11, by irradiating the region R passing through the healthy / important organ from the sweep region, irradiation to the healthy / important organ can be prevented.

[Fourth Embodiment]
FIG. 12 is a conceptual diagram showing a configuration of a charged particle beam irradiation system according to the fourth embodiment. FIG. 13 is a conceptual diagram showing a configuration of a modified example of the charged particle beam irradiation system according to the fourth embodiment.

  This embodiment is a modification of the first embodiment or the third embodiment. The charged particle beam irradiation system in the fourth embodiment includes a plurality of irradiation particle beam control devices 100. Each irradiation particle beam control device 100 finally converges the irradiation particle beam to the target portion 5 of the irradiation object 1. Moreover, each irradiation particle beam control apparatus 100 is irradiating the irradiation particle beam from a different direction.

  FIG. 12 shows a case where irradiation is performed from directions orthogonal to each other. FIG. 13 shows a case where irradiation is performed from opposite directions. Irradiation particle beams supplied to the respective irradiation particle beam control devices 100 are supplied from the same accelerator 10, but may be supplied from different extraction electromagnets 15. Alternatively, they may be supplied from the same extraction electromagnet 15 and branched and supplied respectively.

  In this way, by supplying irradiation particle beams from a plurality of paths, irradiation to portions other than the target portion 5 can be further reduced.

[Other Embodiments]
As mentioned above, although some embodiment of this invention was described, these embodiment is shown as an example and is not intending limiting the range of invention.

  Moreover, you may combine the characteristic of each embodiment. For example, you may combine the characteristic of comprising the support part 130 in 2nd Embodiment so that rotation is possible, and the characteristic of the control in two directions in 3rd Embodiment. Further, each embodiment or a combination thereof may be applied to a system using a gantry.

  Furthermore, these embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are also included in the invention described in the claims and the equivalents thereof.

  DESCRIPTION OF SYMBOLS 1 ... Irradiation object, 5 ... Target part, 7 ... Electromagnet for diffusion, 10 ... Accelerator, 11 ... Vacuum container for circular beam, 12 ... Deflection electromagnet, 12a ... Deflection electromagnet power supply, 13 ... Incident electromagnet, 14 ... High frequency acceleration cavity 14a ... high frequency generator, 15 ... extraction electromagnet, 16 ... circular beam converging quadrupole electromagnet, 16a ... quadrupole electromagnet power source, 17 ... incident vacuum vessel, 17a ... ion source, 17b ... incident accelerator, 18 ... beam Emitting unit, 100 ... Irradiation particle beam control device, 111, 111a, 111b ... First in-plane diffusion electromagnet, 112, 112a, 112b ... First in-plane converging electromagnet, 121, 121a, 121b ... Second in-plane diffusion Electromagnets 122, 122a, 122b ... electromagnet for converging in the second plane, 130 ... support part, 131 ... electromagnet mounting bar, 132 ... support plate, 200 ... charging Child-ray irradiation system

Claims (6)

An irradiation particle beam control apparatus for controlling an irradiation particle beam having a charge taken out along one orbital axis to irradiate an irradiation object,
Two first in-plane diffusion electromagnets that generate a magnetic field that faces each other across the path of the irradiation particle beam and bends the irradiation particle beam in a direction in which the irradiation particle beam is diffused from the orbital axis;
The movement direction of the irradiation particle beam is arranged downstream of the two first in-plane diffusion electromagnets, facing each other across the irradiation particle beam passage, and bent by the first in-plane diffusion electromagnet. Two first in-plane converging electromagnets that generate a magnetic field that bends the irradiated particle beam in a direction to converge toward the orbital axis direction;
A support part for supporting the two first in-plane diffusion electromagnets and the two first in-plane converging electromagnets;
An irradiation particle beam control device comprising: The first in-plane diffusion electromagnet is configured to diffuse the irradiated particle beam from the orbital axis in a first plane along the activation axis,
The irradiation particle beam is arranged downstream of the two first in-plane converging electromagnets in the moving direction of the irradiation particle beam so as to be opposed to each other across the passage of the irradiation particle beam. Two second in-plane diffusion electromagnets for generating a magnetic field that bends in a direction diffusing from the orbital axis in a second plane orthogonal to the one plane;
The movement direction of the irradiation particle beam is arranged downstream of the two second in-plane diffusion electromagnets, is opposed to each other across the passage of the irradiation particle beam, and is bent by the second in-plane diffusion electromagnet. Two second in-plane converging electromagnets for generating a magnetic field that bends the irradiated particle beam in a direction to converge in the orbital axis direction;
The irradiation particle beam control device according to claim 1, further comprising:   The irradiation particle beam control apparatus according to claim 1, wherein the support portion is configured to be rotatable around the orbital axis. A deflecting electromagnet that forms a magnetic field for deflection in a circumferential path of charged particles, a high-frequency acceleration cavity that imparts energy to the charged particles, and a beam emitting unit that takes out the charged particles as an irradiation particle beam along one orbital axis An accelerator having
An irradiation particle beam control device for controlling the irradiation particle beam to irradiate the irradiation object;
A charged particle beam irradiation system comprising:
The irradiation particle beam control device comprises:
Two first in-plane diffusion electromagnets that generate a magnetic field that faces each other across the path of the irradiation particle beam and bends the irradiation particle beam in a direction in which the irradiation particle beam is diffused from the orbital axis;
The movement direction of the irradiation particle beam is arranged downstream of the two first in-plane diffusion electromagnets, facing each other across the irradiation particle beam passage, and bent by the first in-plane diffusion electromagnet. Two first in-plane converging electromagnets for generating a magnetic field that bends the irradiated particle beam in a direction for converging in the orbital axis direction;
A support part for supporting the two first in-plane diffusion electromagnets and the two first in-plane converging electromagnets;
A charged particle beam irradiation system comprising: An irradiation particle beam control method for controlling an irradiation particle beam in which charged particles accelerated to irradiate an irradiation object are extracted along one orbital axis,
Two first in-plane diffusion electromagnets for diffusing the irradiated particle beam from the orbital axis;
After the first plane diffusion step, two first in-plane focusing electromagnets converge the irradiated particle beam diffused in the first plane diffusion step in the orbital axis direction,
The irradiation particle beam control method characterized by having. In the first plane diffusion step, the irradiation particle beam is diffused in a first plane along the orbital axis,
A second plane diffusion step in which two second in-plane diffusion electromagnets diffuse the irradiated particle beam from the orbital axis in a second plane perpendicular to the first plane along the orbital axis;
After the second plane diffusion step, two second in-plane focusing electromagnets converge the irradiated particle beam diffused in the second plane diffusion step in the orbital axis direction,
The irradiation particle beam control method according to claim 5, further comprising:

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