JP2015000090A - Particle beam treatment apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a compact particle beam treatment apparatus.SOLUTION: A particle beam treatment apparatus 100 includes: a synchrotron 400; and a beam transport device 500, the transport device 500 is set with two or more inclined set deflection parts, and inclinedly linear parts are formed between the inclined deflection parts. By generating a dispersion function in the inclined linear part, size of an opening part of an electromagnet installed in the linear part is reduced to suppress power consumption.

Description

  The present invention relates to a particle beam therapy apparatus for treating a tumor such as cancer by irradiation with a charged particle beam (a heavy ion beam such as a proton beam or a carbon ion beam).

  As one of the cancer treatment methods, particle beam therapy is known in which an affected area is irradiated with a charged particle beam (a heavy particle beam such as a proton beam or carbon ion). When ions such as protons and carbon ions are incident on a material with high energy, a lot of energy is lost at the end of the range. In particle beam therapy, this property is used to irradiate a patient with a charged particle beam so that much energy is lost in cancer cells. Then, cancer cells can be destroyed without damaging surrounding healthy tissues. In particle beam therapy, the spatial spread and energy of the charged particle beam are adjusted to form a dose distribution that matches the shape of the affected area.

  A particle beam therapy system used for particle beam therapy includes an ion source, an accelerator for accelerating ions generated from the ion source, a beam transport device for transporting a charged particle beam emitted from the accelerator, and a charged particle beam to an affected area with a desired dose distribution. An irradiation device for irradiation is provided.

  Examples of the accelerator used in the particle beam therapy system include a synchrotron and a cyclotron. These accelerators have a function of accelerating incident ions to a predetermined energy and emitting them as charged particle beams.

  The charged particle beam emitted from the accelerator is transported to the irradiation device by the beam transport device. The beam transport device is equipped with a deflecting electromagnet that greatly changes the traveling direction of the charged particle beam, a steering electromagnet that finely adjusts the traveling direction of the charged particle beam, and a quadrupole electromagnet that imparts convergence and divergence to the charged particle beam. By appropriately adjusting the amount of excitation of the electromagnet, a charged particle beam having an appropriate size and position is transported to the irradiation device.

  In the particle beam therapy system, the beam path is branched from one accelerator in the middle of the transport system, and multiple treatment rooms are set up, or a charged particle beam is irradiated to the affected area from multiple directions. For example, a plurality of beam transport devices and irradiation devices such as two directions from the horizontal direction and the vertical direction may be installed. When a plurality of treatment rooms are provided, a deflecting electromagnet is installed at a branching point of the charged particle beam transport path, and a path for transporting the charged particle beam can be determined depending on whether the deflecting electromagnet is excited. In addition, when a charged particle beam is emitted from a plurality of directions (for example, a horizontal direction and a vertical direction) with respect to one treatment room, the particle beam therapy apparatus is a first irradiation device that emits a charged particle beam from the horizontal direction. And a second irradiation device for emitting a charged particle beam from the vertical direction. Thus, when the charged particle beam is irradiated from a direction different from the horizontal direction, the charged particle beam needs to be swung up or down at least once by the transport device. A deflecting electromagnet is also used when swinging up or down. An example of such a conventional transportation system arrangement is disclosed in Patent Document 1.

Japanese Patent No. 3574334

  In the conventional particle beam therapy system, the deflection electromagnet provided in the beam transport device switches the course for transporting the charged particle beam to a plurality of treatment rooms and a plurality of irradiation devices, and swings up the course for multi-directional irradiation. Used for. In such a swing-up unit, a deflection unit may be composed of a plurality of deflection electromagnets having the same deflection angle in order to reduce the size of the deflection electromagnet, and a quadrupole electromagnet may be inserted in order to eliminate the dispersion function between them. However, in that case, the beam size of the charged particle beam in the gap direction of the deflecting electromagnet becomes large, and it becomes necessary to widen the gap of the deflecting electromagnet. For this reason, the current of the deflecting electromagnet power source is increased, which causes an increase in power consumption and introduction cost of the apparatus.

  In the present invention, the excitation amount of the quadrupole electromagnet placed between the plurality of deflecting electromagnets constituting the deflecting unit included in the beam transport device of the particle beam therapy system is made smaller than a value that can make the downstream dispersion function zero. As a result, the divergence effect of the quadrupole electromagnet is suppressed, and the downstream beam size in the gap direction can be suppressed as compared with the prior art.

  According to the present invention, the course of the charged particle beam and the swinging up of the charged particle beam in the beam transport apparatus can be realized in one place, and the apparatus can be downsized.

1 is an overall configuration diagram of a particle beam therapy system according to a first embodiment of the present invention. It is equipment arrangement | positioning of the deflection | deviation part in the particle beam therapy system of the 1st Embodiment of this invention. It is a figure which shows the change of the beam size of the charged particle beam at the time of using the deflection | deviation part with which the particle beam therapy apparatus of 1st Embodiment is equipped, and the deflection | deviation part with which the conventional particle beam therapy apparatus is used. is there. It is a figure which shows the change of the dispersion function of a charged particle beam in the case where the deflection | deviation part with which the particle beam therapy apparatus of 1st Embodiment is equipped, and the deflection | deviation part with which the conventional particle beam therapy system is used. is there. It is an elevational view of a treatment room and an inclined straight part constituting the particle beam therapy system according to the first embodiment of the present invention. It is an elevational view of a treatment room and an inclined straight part constituting the particle beam therapy system according to the first embodiment of the present invention. It is a whole block diagram in the particle beam therapy system of the 2nd Embodiment of this invention.

(First embodiment)
The first embodiment of the present invention will be described below with reference to the drawings. In the present embodiment, a carbon beam therapy apparatus that irradiates an affected area with a carbon ion beam (hereinafter referred to as an ion beam) will be described as an example.

  FIG. 1 shows a schematic diagram of a particle beam therapy system (carbon beam therapy system) 100 of the present embodiment. The carbon beam treatment apparatus 100 includes an ion source 200, an incident linear accelerator 300, a synchrotron 400, a transport device 500, two treatment rooms (first treatment room) 610, and a treatment room (second treatment room) 620. Prepare.

  The carbon ions generated by the ion source 200 are accelerated to 6 MeV per nucleon by the incident accelerator and then incident on the synchrotron 400. In the synchrotron 400, the incident carbon ions are accelerated to the kinetic energy used for the treatment (up to 430 MeV per nucleon) and taken out to the transport device 500.

  The treatment room 610 and the treatment room 620 have a plurality of irradiation ports having different heights. Specifically, the carbon beam therapy apparatus 100 is provided with six irradiation ports. Each of the treatment room 610 and the treatment room 620 can be irradiated with an ion beam from three directions. The first treatment room 610 irradiates the ion beam from the horizontal direction (first horizontal irradiation port) 511 and the vertical irradiation port (first vertical irradiation port) 521 that irradiates the ion beam from the vertical direction. And an oblique irradiation port (first oblique irradiation port) 531 for irradiating an ion beam from an oblique direction. The second treatment room 610 irradiates the ion beam from the horizontal direction (second horizontal irradiation port) 512 and the vertical irradiation port (second vertical irradiation port) 522 that irradiates the ion beam from the vertical direction. And an oblique irradiation port (second oblique irradiation port) 532 for irradiating an ion beam from an oblique direction. The ion beam emitted from the synchrotron 400 passes through the beam path determined by the transport device 500 and is transported to any one of the six irradiation ports.

  The transport apparatus 500 includes a duct through which the ion beam passes and a vacuum pump (not shown) for evacuating the inside of the duct, and the ion beam passes through the vacuum. The transport apparatus 500 includes deflecting units 561 to 569 that deflect the ion beam and linear portions 571 to 585 that linearly move the ion beam. A deflecting electromagnet for bending the beam path is used for the deflection unit of the transport apparatus 500.

  When a plurality of irradiation ports having different heights are provided, the transport device needs to swing the ion beam path upward at least once. In the carbon beam therapy apparatus 100 of the present embodiment, the synchrotron 400, the first horizontal irradiation port 511, and the second horizontal irradiation port 512 are arranged on the same level (floor). The first vertical irradiation port 521, the first oblique irradiation port 531, the second vertical irradiation port 522, and the second oblique irradiation port 532 are disposed above the synchrotron 400. In this embodiment, the deflection of the ion beam is realized by installing the deflecting unit 561 at an angle. The deflecting unit 561 is a common deflecting unit connected to the first vertical irradiation port 521, the first oblique irradiation port 531, the second vertical irradiation port 522, and the second oblique irradiation port 532. The deflection electromagnet 541 and the deflection electromagnet 542 provided in the deflection unit 561, and the deflection electromagnet 545 and the deflection electromagnet 546 provided in the deflection unit 563 are inclined by 45 degrees with respect to the horizontal plane. As a result, the straight portions 572 and 573 between the deflecting portion 561 and the deflecting portion 563 are straight portions having an inclination of 45 degrees.

  The deflection electromagnets 541 to 557 used in the transport apparatus 500 in this embodiment are C-type laminated steel plate electromagnets in which C-shaped steel plates are stacked in the beam traveling direction of the ion beam. All the deflecting magnets generate a magnetic field in the gap by exciting a current in the coil and deflect the trajectory of the ion beam passing through the gap. The amount of excitation current is adjusted according to the energy of the ion beam so that the deflection angle is 45 degrees. In the present embodiment, two deflection electromagnets having a deflection angle of 45 degrees are used as one set, and a deflection unit having a deflection angle of 90 degrees is configured in total. In this embodiment, nine deflection units 561 to 569 are provided. All the deflecting units include two deflecting electromagnets and one quadrupole electromagnet (quadrupole electromagnets 711 to 719) installed between the deflecting electromagnets. A plurality of quadrupole electromagnets (not shown) are also installed in each of the straight portions 571 to 585. Three quadrupole electromagnets are provided in each of the inclined straight portions 572 and 573, four quadrupole electromagnets are provided in each of the straight portions 571, 574 to 576 and 580 to 582, and four quadrupole electromagnets are provided in the straight portions 577 to 579 and 583 to 585. Three each are arranged. The quadrupole electromagnet has the effect of converging the ion beam in a certain direction and diverging in the direction perpendicular to it, and by setting the appropriate amount of excitation, the ion beam is placed in the design beam passage area defined by the inner shape of the vacuum duct. At the same time, it is possible to irradiate the affected area at the irradiation point with an appropriate beam size.

  There are branch points 591 to 595 on the beam path in the transport device 500. A deflection electromagnet 541 is installed at the branch point 591, a deflection electromagnet 543 is installed at the branch point 592, a deflection electromagnet 546 is installed at the branch point 593, a deflection electromagnet 548 is installed at the branch point 594, and a deflection electromagnet is installed at the branch point 595. 550 is installed. These deflection electromagnets 541, 543, 546, 548, and 550 play a role of deflecting the ion beam and switching the course of transporting the ion beam. That is, the ion beam that has reached the branch point is deflected if the deflection electromagnet is being excited (ON), and goes straight if it is not being excited (OFF). For example, when irradiation is performed at the first horizontal port 511 of the treatment room 610, the deflection electromagnet 541 is not excited (turned off), and the deflection electromagnet 546 is excited (turned on). Thus, the irradiation port through which the ion beam is transported can be selected by turning on / off the excitation of the deflection electromagnet.

  Next, FIG. 2 shows the configuration of the deflection unit used in this embodiment. As described above, the deflecting unit includes two 45-degree deflecting electromagnets (5401 and 5402), and the quadrupole electromagnet 7101 is provided between the deflecting electromagnet 5401 and the deflecting electromagnet 5402. The quadrupole electromagnet 7101 has a role of adjusting the dispersion function of the ion beam being transported and the ion beam to be irradiated. The dispersion function is a parameter indicating the correlation between the momentum deviation of individual particles constituting the ion beam and the position deviation from the design trajectory. If the dispersion function has a non-zero value, the beam size is further expanded due to the spread of momentum. The dispersion function is generated by the ion beam passing through the deflecting electromagnet. Since the angle at which the charged particles are deflected by the magnetic field depends on the momentum thereof, the charged particles having a large momentum have a small deflection angle, and the charged particles having a small momentum have a large deflection angle. In this way, momentum dependence occurs in the deflection angle of each charged particle in the deflection electromagnet, and the position shifts as the ion beam is transported through the transport device. In this embodiment, a quadrupole electromagnet 7101 is used between two deflection electromagnets (5401, 5402) in order to adjust the dispersion function generated in the deflection unit. The quadrupole electromagnet 7101 has an effect of converging the ion beam in a direction (X direction) parallel to the deflection surface and perpendicular to the beam traveling direction, and diverging the ion beam in a direction perpendicular to the deflection surface (Y direction). With such a configuration of the deflecting unit, the dispersion function in the X direction generated by the upstream deflecting electromagnet 5401 is converged at the position of the quadrupole electromagnet. Then, for example, in the excitation amount of a certain quadrupole electromagnet, the dispersion function generated in the upstream deflection electromagnet can be set to 0 after passing through the downstream deflection electromagnet. Such a deflection unit in which no dispersion function occurs is defined as an achromatic deflection unit. By using an achromatic deflecting unit as the deflecting unit, the dispersion function of the subsequent straight line unit becomes 0, and the ion beam can be transported to the irradiation point while suppressing the beam size. FIG. 2 shows a design trajectory 8001 in the achromatic deflection unit, a trajectory 8003 drawn by charged particles having a large momentum, and a trajectory 8002 drawn by charged particles having a small momentum. As a feature of the achromatic deflection unit, the amount of excitation of the quadrupole electromagnet tends to be larger than that of the quadrupole electromagnet used for the other linear portions. As shown in the trajectory shape of FIG. 2, when the quadrupole electromagnet 7101 is regarded as a lens, the focal length is about the trajectory length of the deflection electromagnet. Then, a large divergence force is received in the Y direction that receives the divergence action by the quadrupole electromagnet 7101, and the downstream Y-direction beam size becomes large. Therefore, the size of the electromagnet tends to increase in the straight line portion downstream of the achromatic deflection portion. Conventionally, it has been necessary to take measures such as inserting a quadrupole electromagnet having a convergence effect in the Y direction immediately after the deflection electromagnet. Accordingly, the power consumption of the apparatus increases. Further, as in the present embodiment, when there is a straight line portion inclined in the transport route or a straight line portion in the vertical direction, maintenance can be ensured and the time required for installation can be increased due to an increase in installed equipment.

  Here, FIG. 3 shows changes in the beam size in the inclined linear portions 572 and 573 when the conventional achromatic deflection unit is used and when the excitation amount of the quadrupole electromagnet is made smaller than the achromatic condition applied in the present embodiment. Show. The starting point in the graph of FIG. 3 is the entrance of the deflecting electromagnet 541, and the end point is the exit of the deflecting electromagnet 546. That is, the beam size at the inclined straight portions 572 and 573 having a total length of about 23 m is shown. The horizontal axis in FIG. 3 represents the distance in the beam traveling direction, and the vertical axis represents the beam size. Further, BM in FIG. 3 indicates a deflection electromagnet, and QM indicates a quadrupole electromagnet. The beam size of the ion beam is defined as twice the standard deviation of the position of each particle projected in the X and Y directions. The distribution in the phase space of the ion beam at the start point is described by the Twiss parameter, the horizontal direction is α = 3.1, β = 6.8 m, the vertical direction is α = 0.8, β = 4.1 m. is there. The excitation amount of the quadrupole electromagnet is adjusted so that the ion beam under this condition takes the same value even at the long point. The emittance of the ion beam at the start point is 0.75 π mm · mrad in the horizontal direction and 3.8 π mm · mrad in the vertical direction. The standard deviation of the momentum deviation was 0.02%. As described above, the amount of excitation of the quadrupole electromagnet (QM) between the first two deflecting electromagnets indicated by BM in FIG. 3 is smaller under the condition of this embodiment than the conventional achromatic condition. For this reason, the divergence of the ion beam in the Y direction is suppressed, and the ion beam size increases up to 37 mm downstream of the BM indicated by the arrow under the achromatic condition, whereas it can be suppressed up to 28 mm in this embodiment. For this reason, the size of the opening portion of the electromagnet at the inclined linear portion can be suppressed as compared with the conventional case, and the power consumption can be reduced. Similarly, the maximum value of the beam size in the X direction can be made smaller in the present embodiment, and the power consumption of the electromagnet in the inclined linear portion can also be made smaller than in the conventional example. In the present embodiment, the dispersion function of the inclined straight line portion does not become zero because the deflection portion that satisfies the achromatic condition is not used. This is shown in FIG. Conventionally, the dispersion function is not zero, but only in the deflecting portion. In this embodiment, the dispersion function is generated over the entire inclined linear portion. However, as can be seen from the results of FIG. 3, the effect of increasing the beam size due to the influence of the dispersion function can be ignored if the variation in the momentum is small. In this embodiment, the beam size in both the X direction and the Y direction is smaller than in the conventional case. Can be small. Furthermore, the dispersion function that remains slightly at the exit of the inclined straight line portion can be eliminated between the downstream straight line portion and the deflection portion toward the irradiation point, and does not affect the irradiation performance at all.

  Furthermore, FIG. 5 shows a cross-sectional view of the treatment room 610 viewed from the direction of arrow A in FIG. The building of the present embodiment has a two-story structure, and a transport path following the first vertical irradiation port 521 and the first oblique irradiation port 531 is installed on the second floor part of the two-story, A straight line portion 577 and a first treatment room 610 are provided following one horizontal irradiation port 511. The first treatment room 610 has a movable treatment table 612 on which a patient 611 lies, and the position of the treatment table is determined for each irradiation so that the affected part is located at the irradiation point 630. An irradiation device 640 is on the beam path immediately before the irradiation point 630. In this embodiment using the scanning irradiation method, scanning electromagnets 651 and 652 for scanning an ion beam and a position monitor for measuring the beam position are placed in the irradiation apparatus. It is also possible to use a scatterer irradiation method instead of the scanning irradiation method. In this case, a scatterer, a collimator, or the like is installed in the irradiation device instead of the scanning electromagnet. By taking the transport route as in the present embodiment, a wide space 700 can be taken in the second floor portion directly above the straight line portion 577 following the horizontal irradiation port. By placing the power source of each device such as a transport electromagnet or a synchrotron electromagnet at this place, the building space can be used effectively, and as a result, the building volume can be reduced.

  In addition, although the inclination of the inclined straight portions 572 and 573, that is, the inclination angle of the deflecting portion 561 is 45 degrees in this embodiment, other angles may be used. For example, FIG. 6 shows a cross-sectional view of the treatment room when the inclination angle is 22.5 degrees. The feature in this case is that a wider space 701 can be secured on the upper floor of the horizontal irradiation port and a longer straight part can be taken upstream of the oblique irradiation port as compared to when the inclination angle is 45 degrees. Since a long straight portion can be taken upstream of the irradiation port, it is easy to arrange a transportation system device such as a quadrupole electromagnet, and there are advantages such that the convergence force of the quadrupole electromagnet immediately before the irradiation point 630, that is, the amount of excitation can be reduced. On the other hand, the horizontal length of the building becomes large. Conversely, if the inclination angle is larger than 45 degrees, the length of the straight line upstream of the oblique irradiation port and the space on the upper floor of the horizontal irradiation port are reduced, while the site area of the building can be reduced. With these points in mind, the tilt angle can be selected according to the shape of the land at the installation site.

  Furthermore, among the six irradiation ports provided in the carbon beam therapy apparatus 100 of the present embodiment, some irradiation ports and the accompanying transport apparatus can be omitted. For example, the oblique irradiation port 532 of the second treatment room 602, the upstream straight line portion 584, the deflection part 568, and the horizontal straight line part 581 are omitted, and the second treatment room 602 includes the vertical irradiation port 512 and the second horizontal irradiation port 522. It is also possible to allow irradiation from only two directions. In that case, it is possible to reduce the cost of the omitted equipment.

(Second Embodiment)
Hereinafter, a second embodiment of the present invention will be described with reference to the drawings. The particle beam therapy apparatus (carbon beam therapy apparatus) 1100 of this example includes two therapy rooms, as in the first example. Here, the difference from the carbon beam therapy apparatus 100 of the first embodiment will be mainly described.

  In FIG. 7, the schematic of the carbon beam therapy apparatus 1100 of a present Example is shown. The carbon beam therapy apparatus 1100 of the present embodiment is different from the carbon beam therapy apparatus 100 of the first embodiment in the shape of the transport device and the arrangement of the treatment rooms. Similar to the carbon beam therapy apparatus 100 of the first embodiment, the carbon beam therapy apparatus 1100 of the present embodiment includes inclined linear portions 1572 and 1573 and horizontal linear portions 1571, 1574 to 1576, and 1580 to 1582. Similarly to the first embodiment, the deflecting units 1561 to 1569 deflect the ion beam, and the deflected ion beam is irradiated to the irradiation points in the treatment rooms 1610 and 1620. The carbon beam therapy apparatus 1100 of the present embodiment is different from the carbon beam therapy apparatus 100 of the first embodiment in that the deflection units 1564, 1565, 1567, and 1568 have only one deflection electromagnet having a deflection angle of 54.74 degrees. Consists of. The deflection angle of the four deflection electromagnets 1546, 1548, 1552, and 1554 can be made common by setting the deflection angle of the deflection electromagnet to an arctangent function of the square root of 2, that is, 54.74 degrees. The feature of this embodiment is that the angle between the straight portions 1577 and 1583 directed to the horizontal irradiation ports 1511 and 1512 and the horizontal straight portion is 90 degrees or less, thereby reducing the cost of the deflecting electromagnet and reducing the power consumption.

  Furthermore, the sectional view of the treatment room of this embodiment is the same as that in FIG. 6, and the lengths of the straight portions 1578 and 1584 toward the oblique irradiation ports are equal to the lengths of the straight portions 1579 and 1585 toward the vertical irradiation ports 1521 and 1522. be able to. Therefore, by appropriately arranging the quadrupole electromagnet, the beam size can be adjusted while suppressing the excitation amount of the quadrupole electromagnet. On the other hand, by setting the deflection units 1564, 1565, 1567, and 1568 as the final deflection electromagnet at one deflection electromagnet irradiation point, it is installed in the upstream horizontal straight line portion or oblique straight line portion in order to eliminate the dispersion function at the irradiation point. It is necessary to adjust the excitation amount of the quadrupole electromagnet. Also in the present embodiment, the dispersion function at the inclined linear portions 1572 and 1573 is not erased, and the dispersion function is erased at the linear portion finally toward the irradiation point. In this embodiment, the deflection portions 1564, 1565, 1567, and 1568 have the same deflection angle in the deflection portions 1561, 1562, and 1563 at the entrance and exit of the inclined straight portion, and the straight portion upstream of the oblique irradiation port and the straight line upstream of the vertical irradiation port. When the lengths of the portions are the same, the angles of the deflecting portions 1564, 1565, 1567, and 1568 are 54.74 degrees as described above. By setting this angle to another value, the length of the straight line portion upstream of each port can be adjusted. Further, as with the carbon beam therapy apparatus 100 described in the first embodiment, as the inclination angle of the inclined linear portions 1572 and 1573 is reduced, a space is obtained on the upper floor of the horizontal irradiation port, while the width of the building is increased. . Based on the above, in an actual carbon beam therapy apparatus, a deflection angle and an inclination angle may be selected.

  Furthermore, like the first embodiment, some of the six irradiation ports included in the carbon beam therapy apparatus 1100 of this embodiment can be omitted and a transport device associated therewith. For example, it is possible to omit the upstream straight portion 1584, the deflecting portion 1554, and the horizontal straight portion 1581 of the oblique irradiation port of the treatment room 1602 so that irradiation can be performed only from two directions of the vertical irradiation port 1522 and the horizontal irradiation port 1512. . In that case, it is possible to reduce the cost of the omitted equipment.

  In addition, although Example 1 and 2 demonstrated the carbon beam therapy apparatus as an example as a particle beam therapy apparatus, a proton beam therapy apparatus may be sufficient.

100, 1000 Carbon beam therapy apparatus 200 Ion source 300 Linear accelerator 400 Synchrotron 500 Transport apparatus 511-512, 1511-1512 Horizontal irradiation ports 521-522, 1521-1522 Vertical irradiation ports 531-532, 1531-1532 Oblique irradiation ports 541 ~ 558, 1546, 1548, 1552, 1554, 5401-5402 Bending electromagnets 561-569, 1561-1569 Deflection parts 571-585, 1571-1585 Straight line parts 610, 620, 1610, 1620 Treatment room 611 Patient 612 Movable treatment table 630 Irradiation point 640 Irradiation device 651, 652 Scanning electromagnet 700, 701 Space 711-719, 1711-1715, 7101 Quadrupole electromagnet 8001-8003 Particle trajectory

Claims (6)

An accelerator to accelerate the charged particle beam;
An irradiation apparatus for irradiating an irradiation target installed at an irradiation point with the charged particle beam from a plurality of directions;
A particle beam therapy apparatus comprising a beam transport device that determines a transport path of the charged particle beam taken out from the accelerator and transports the charged particle beam to the irradiation device,
The beam transport device includes a deflection unit that deflects the charged particle beam, and a linear unit that linearly moves the charged particle beam,
The deflection unit includes one or more deflection electromagnets, and at least one of the deflection units is installed at a branch point of a beam transport path,
Each of the straight portions includes at least two quadrupole electromagnets,
The plurality of deflection units are installed with an inclination of less than 90 degrees with respect to a horizontal plane, and the two inclined deflection units are connected by an inclined linear part. . The particle beam therapy system according to claim 1, wherein
In the case where the deflection unit has a plurality of deflection electromagnets, a quadrupole electromagnet is provided between the deflection electromagnets and the deflection electromagnets. The particle beam therapy system according to claim 2, wherein
A particle beam therapy system, wherein a dispersion function of the charged particle beam passing therethrough is adjusted using a quadrupole electromagnet disposed between the deflection electromagnets. In the particle beam therapy system according to claim 3,
A particle beam therapy system characterized in that the quadrupole electromagnet is excited so as to generate a dispersion function of the charged particle beam passing through the inclined straight portion. In the particle beam therapy system according to any one of claims 1 to 4,
A particle beam therapy system comprising: a plurality of the irradiation points; and an irradiation device that irradiates the charged particle beam from a plurality of directions for each irradiation point. In the particle beam therapy system according to any one of claims 1 to 4,
A particle beam therapy system, wherein an inclination angle between the inclined linear part and the inclined deflecting part is 22.5 degrees or more and 67.5 degrees or less.