Particle beam measuring device

Abstract

Provided is a particle beam measuring device that contributes to making work simpler and more efficient during beam adjustment, beam evaluation, or similar, as well as to saving space in a storage area for attachments or similar. This particle beam measuring device (10) comprises: a transport mechanism (40) that is for transporting a patient to the inside of a rotary gantry and causing an affected part of the patient to coincide with an isocenter through which a particle beam (11) passes; a phantom (20) on which the particle beam (11) is made to be incident for the purpose of measurement; and an attachment (30) that attaches the phantom (20) as an end effector of the transport mechanism (40).

Description

Particle beam measurement equipment

[0001] An embodiment of the present invention relates to a technique for measuring a particle beam used in radiation therapy.

[0002] In radiation therapy, which treats cancer cells in the human body by irradiating them with high-energy particle beams, beam adjustment before treatment begins and periodic beam quality evaluation are extremely important for ensuring appropriate irradiation.Beam measurements performed during beam adjustment and beam quality evaluation are performed in the perpendicular and parallel directions of the particle beam.

[0003] Here, measurements in the direction perpendicular to the particle beam target beam size, beam spread, irradiation position accuracy, dose distribution, etc. Measurements in the direction parallel to the particle beam target beam range, beam incidence angle, etc. Generally, measurements of particle beams used in particle beam therapy systems are performed by installing a gantry on the floor of the treatment room and irradiating the particle beam onto a phantom attached to the gantry with an attachment.

[0004] Japanese Patent Application Laid-Open No. 2021-137106

[0005] In the measurement of the particle beam described above, the installation of the mount and the replacement of attachments were required multiple times, which made the work inefficient. Furthermore, it was necessary to always secure a large space for storing the mount.

[0006] The embodiments of the present invention have been made in consideration of the above circumstances, and have an object to provide a particle beam measurement device that contributes to simplifying and improving the efficiency of operations when adjusting beams and evaluating beam quality, and to saving space required for storing attachments, etc.

[0007] The particle beam measurement device according to the embodiment includes a transport mechanism for transporting a patient inside a rotating gantry and aligning the affected area with the isocenter through which the particle beam passes, a phantom into which the particle beam is incident for measurement, and an attachment for attaching the phantom as an end effector of the transport mechanism.

[0008] Furthermore, a particle beam measurement device according to an embodiment includes a phantom into which a particle beam is incident for measurement, and an attachment for attaching the phantom as an end effector of a transport mechanism to an upper surface of a top plate of the transport mechanism for transporting a patient inside a rotating gantry and aligning an affected area with an isocenter through which the particle beam passes. The attachment includes a substrate detachably held on the upper surface of the top plate of the transport mechanism, and a support member for supporting the phantom from the substrate so that the phantom is positioned outside the top plate of the transport mechanism and the main axis of the phantom is approximately perpendicular to the particle beam.

[0009] According to an embodiment of the present invention, a particle beam measurement device is provided that contributes to simplifying and improving the efficiency of operations when adjusting a beam and evaluating beam quality, and to saving space for storing attachments and the like.

[0010] (A) A side view showing a state of an attachment before a phantom is attached to a transport mechanism in a particle beam measurement device according to an embodiment, (B) a side view showing a state of the attachment after the phantom is attached, (C) a plan view showing a state of the attachment after the phantom is attached, and (D) a front view showing a state of the attachment after the phantom is attached. A perspective view of a transport mechanism constituting a particle beam measurement device according to an embodiment. A cross-sectional view showing an embodiment of a rotating gantry-type radiation therapy system to which a particle beam measurement device is applied. (A) A top view showing the attitude of the transport mechanism in an initial stage, (B) a top view showing the attitude of the transport mechanism in a mounting stage, (C) a top view showing the attitude of the transport mechanism in a measurement stage, and (D) a top view showing the attitude of the transport mechanism in a standby stage.

[0011] 1A is a side view showing a state of an attachment 30 before a phantom 20 is mounted on a transport mechanism 40 in a particle beam measurement system 10 (FIG. 2) according to an embodiment. As described above, the particle beam measurement system 10 includes a transport mechanism 40 for transporting a patient inside a rotating gantry 51 (FIG. 3) and aligning an affected area of ​​the patient with an isocenter 52 through which a particle beam 11 passes, a phantom 20 into which the particle beam 11 is incident for measurement, and an attachment 30 to which the phantom 20 is attached as an end effector of the transport mechanism 40.

[0012] 1B is a side view showing the state of the attachment 30 after the phantom 20 has been attached. The phantom 20 is used to measure and confirm the relationship between the energy of the particle beam 11 and its irradiation depth, i.e., the position where the Bragg peak appears. Furthermore, when scanning the particle beam 11 two-dimensionally, three-dimensionally, or four-dimensionally, the measurement also confirms that the scanning surface, called the irradiation field, is within a set range. Since the particle beam 11 is irradiated accurately at a targeted position in human tissue during treatment, this measurement and confirmation work is performed by attaching the phantom 20 before the start of treatment or periodically.

[0013] 1C is a plan view showing the state of the attachment 30 after the phantom 20 has been attached. As shown, the attachment 30 has a substrate 31 that is detachably held on the upper surface of the top plate 41 of the transfer mechanism 40, and a support member 32 that supports the phantom 20 from the substrate 31 so that the main axis 21 of the phantom 20 is approximately perpendicular to the particle beam 11. Although not shown, the top plate 41 and the attachment 30 may be provided with a notch on one side and a pin on the other side for positioning.

[0014] The substrate 31 may be configured to be positioned by a step portion 41 a formed on the upper surface of the top plate 41 of the transfer mechanism 40. Specifically, the substrate 31 may be configured to be positioned on the upper surface of the top plate 41 with the end surface of the substrate 31 aligned with the step portion 41 a.

[0015] The support member 32 is preferably configured so that the phantom 20 is located outside the transfer mechanism 40 and the top plate 41. Specifically, the support member 32 is preferably configured so that the phantom 20 is located outside the transfer mechanism 40 and the top plate 41 and on the path of the particle beam 11.

[0016] 1(D) is a front view showing the state of the attachment 30 after the phantom 20 has been attached. As shown, the attachment 30 has a fixing member 35 that improves the reproducibility of the fixing position relative to the transfer mechanism 40. One end of the L-shaped fixing member 35 is fixed to the substrate 31 via a hinge. Then, as shown by the dashed line in FIG. 1(D), when the L-shaped portion of the fixing member 35 is moved upward, the attachment 30 can be detached from the top plate 41. Then, as shown by the solid line in FIG. 1(D), when the L-shaped portion of the fixing member 35 is moved downward, the attachment 30 can be fixed to the top plate 41.

[0017] 2 is a perspective view of a transport mechanism 40 constituting the particle beam measurement device 10 according to the embodiment. The primary role of the transport mechanism 40 is to place a patient lying on a tabletop 41, transport the patient to under the irradiation port 12, and aim the particle beam 11 at a lesion whose position has been identified in a preliminary examination.

[0018] The transport mechanism 40 of the embodiment supports a top plate 41, to which the phantom 20 is fixed via an attachment 30, at the tip of a seven-axis articulated link structure. Note that the mechanism for transporting the phantom 20 as an end effector is not limited to one constituted by drive joints 42 (42a, 42b, 42c, 42d) using rotating bodies such as motors as shown in the figure, and all or part of it may be constituted by linear moving bodies.

[0019] Furthermore, the phantom 20 as an end effector is not limited to being held by the top plate 41 as shown in the figure. The phantom 20 may also be detachably held by the transport mechanism 40 via an attachment (not shown) with the top plate 41 removed.

[0020] 3 is a cross-sectional view showing an embodiment of a rotating gantry-type radiation therapy system 50 to which the particle beam measurement device 10 is applied. An irradiation port 12 for irradiating a particle beam 11 is fixed to the rotating gantry 51. By rotating the irradiation port 12 together with the rotating gantry 51 around the rotation axis, the particle beam 11 can be irradiated onto the phantom 20 (the affected area of ​​the patient during treatment) from any direction without tilting the top plate 41 of the transport mechanism 40.

[0021] The rotating gantry 51 is a large structure generally having a cylindrical shape, and rotates around a rotation axis (Z-axis) by the rotational drive of multiple rotational drive units 55 circumscribing the outer peripheral surfaces of both edges of the rotating gantry 51. The weight of the rotating gantry 51 is supported by a stationary system (not shown) via the rotational drive units 55. The radiation therapy system 50 positions the phantom 20, which is supported by a transport mechanism 40 also fixed to the stationary system, at an isocenter 52 and rotates the irradiation port 12 about the isocenter.

[0022] In addition to the irradiation port 12, the rotating gantry 51 is also provided with a number of beam transport ducts, beam bending magnets, and other control devices and structures (not shown). The particle beam 11 is generated by accelerating ions (heavy particles or proton ions) generated in an ion source (not shown) using a linear accelerator and then injecting them into a circular accelerator (not shown) to increase their energy to a set level. The particle beam 11 output from the circular accelerator is then transported through a beam transport system (not shown) and irradiated from the irradiation port 12 toward an isocenter 52 located on the rotation axis of the rotating gantry 51.

[0023] Fig. 4(A) is a top view showing the posture of the transfer mechanism 40 in the initial stage, Fig. 4(B) is a top view showing the posture of the transfer mechanism 40 in the mounting stage, Fig. 4(C) is a top view showing the posture of the transfer mechanism 40 in the measurement stage, and Fig. 4(D) is a top view showing the posture of the transfer mechanism 40 in the standby stage.

[0024] The transport mechanism 40 operates with a single touch and automatically sets the resting state of each of the initial stage posture (see FIG. 4(A)), the first posture which is the posture for the attachment stage (see FIG. 4(B)), the second posture which is the posture for the measurement stage (see FIG. 4(C)), and the third posture which is the posture for the standby stage (see FIG. 4(D)). This automatic setting can be performed at any timing when adjusting the beam before the start of treatment and when periodically evaluating the beam quality.

[0025] 4(A) shows the initial stage in which the transport mechanism 40 assumes a position during the actual treatment in order to place the patient on the tabletop 41. The attachment stage in FIG. 4(B) shows the position in which only the tabletop 41 is moved and the attachment 30 with the phantom 20 attached is attached to the transport mechanism 40.

[0026] The measurement stage in Figure 4(C) shows the posture of the transport mechanism 40 in which the drive joints 42 (42a, 42b, 42c, 42d) are operated so that the phantom 20 is positioned at the isocenter 52. In this posture of the measurement stage, it is preferable that only the phantom 20 is positioned on the path of the particle beam 11. The waiting stage in Figure 4(D) shows the posture of the transport mechanism 40 in which the drive joints 42 (42a, 42b, 42c, 42d) are operated so that the phantom 20 is moved away from the position of the isocenter 52.

[0027] By using the particle beam measurement device 10 with the phantom 20 set in this manner, beam adjustment before the start of treatment and periodic beam quality evaluation can be performed on the particle beam 11 used in radiation therapy. In addition, this particle beam measurement device 10 can also be used to evaluate the position of the X-ray irradiation unit attached to the radiation therapy system 50 and to evaluate a three-dimensional imaging device.

[0028] According to at least one of the embodiments of the particle beam measurement device described above, by attaching a phantom via an attachment as an end effector of the transport mechanism, it is possible to contribute to simplification and efficiency of work when adjusting the beam and evaluating the beam quality, as well as to space saving for storing attachments, etc.

[0029] Furthermore, according to at least one embodiment of the particle beam measurement system described above, the substrate 31 is positioned by the step 41a formed on the upper surface of the top plate 41 of the transfer mechanism 40. That is, when the phantom 20 is mounted on the transfer mechanism 40, the attachment 30 is attached by aligning the edge of the substrate 31 with the step 41a, and the substrate 31 is placed on the upper surface of the top plate 41. In this way, by making the attachment 30 detachable from the top plate 41 of the transfer mechanism 40, the fixing position of the attachment 30 can be easily determined when attaching or detaching it. This can effectively contribute to simplification and efficiency of operations such as beam adjustment and beam quality evaluation.

[0030] Furthermore, according to at least one embodiment of the particle beam measurement device described above, the fixing member 35 has a simple configuration in which one end of the L-shape is fixed to the substrate 31 via a hinge. This allows the attachment 30 to be easily attached and detached by the fixing member 35 after the attachment 30 is positioned by the step portion 41a formed on the upper surface of the top plate 41 of the transfer mechanism 40. This can effectively contribute to the simplification and efficiency of operations such as beam adjustment and beam quality evaluation.

[0031] Furthermore, according to at least one embodiment of the particle beam measurement device described above, the transport mechanism 40 can be automatically set to each of the static states of the initial stage posture, the attachment stage posture, the measurement stage posture, and the standby stage posture at any timing with a single touch when performing beam adjustment before the start of treatment and periodic beam quality evaluation. This contributes to simplifying and streamlining the work involved in beam adjustment and beam quality evaluation. Furthermore, when continuously performing beam adjustment and beam quality evaluation when the phantom 20 is positioned at the isocenter 52 and when the phantom 20 is not positioned at the isocenter 52, the transport mechanism 40 can be automatically set to either the measurement stage posture in which the phantom 20 is positioned at the isocenter 52 or the standby stage posture in which the phantom 20 is not positioned at the isocenter 52 with a single touch. This allows beam adjustment and beam quality evaluation without removing the phantom 20 from the top plate 41. This effectively contributes to simplifying and streamlining the work involved in beam adjustment and beam quality evaluation.

[0032] Furthermore, according to at least one embodiment of the particle beam measurement device described above, the support member 32 supports the phantom 20 from the substrate 31 so that the phantom 20 is positioned outside the transport mechanism 40 and the top plate 41. This allows only the phantom 20 to be positioned on the path of the particle beam 11 when performing beam adjustment, beam quality evaluation, etc., with the phantom 20 positioned at the isocenter 52. Furthermore, when the irradiation port 12 rotates around the rotation axis together with the rotating gantry 51, the particle beam 11 can be irradiated onto the phantom 20 from any direction within 360 degrees around the rotation axis. Therefore, when performing beam adjustment, beam quality evaluation, etc., components other than the phantom 20 are prevented from interfering with the particle beam 11, and beam adjustment, beam quality evaluation, etc. can be performed in all directions within 360 degrees under the same conditions. This contributes to improving the accuracy of beam adjustment, beam quality evaluation, etc.

[0033] Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, substitutions, modifications, and combinations can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, as well as the inventions described in the claims and their equivalents.

[0034] 10...particle beam measurement device, 11...particle beam, 12...irradiation port, 20...phantom, 21...main shaft, 30...attachment, 31...substrate, 32...support member, 35...fixing member, 40...transfer mechanism, 41...top plate, 41a...step portion, 42...drive joint, 50...radiation therapy system, 51...rotating gantry, 52...isocenter, 55...rotation drive unit

Claims

1. A particle beam measurement device comprising: a transport mechanism for transporting a patient inside a rotating gantry and aligning the affected area with the isocenter through which the particle beam passes; a phantom into which the particle beam is incident for measurement; and an attachment for attaching the phantom as an end effector of the transport mechanism.

2. A particle beam measurement device according to claim 1, wherein the attachment comprises: a substrate that is detachably held on the top surface of the top plate of the transfer mechanism; and a support member that supports the phantom from the substrate so that the main axis of the phantom and the particle beam are approximately perpendicular to each other.

3. A particle beam measuring device according to claim 1, wherein the attachment is detachably held by the transport mechanism with the top plate removed.

4. A particle beam measuring device according to claim 2 or 3, wherein the attachment has a fixing member that improves the repeatability of the fixed position relative to the transport mechanism.

5. A particle beam measurement device according to claim 2 or claim 3, wherein the transport mechanism can automatically set at least one of a first posture at the stage of attaching the phantom as the end effector, and a second posture at the stage of injecting the particle beam into the phantom and measuring the particle beam.

6. A particle beam measurement device comprising: a phantom into which a particle beam is incident for measurement; and an attachment for attaching the phantom as an end effector of a transport mechanism to an upper surface of a top plate of the transport mechanism for transporting a patient inside a rotating gantry and aligning an affected area with an isocenter through which the particle beam passes, wherein the attachment has: a substrate that is detachably held on the upper surface of the top plate of the transport mechanism; and a support member that supports the phantom from the substrate so that the phantom is positioned outside the top plate of the transport mechanism and the main axis of the phantom is approximately perpendicular to the particle beam.

7. A particle beam measurement device according to claim 6, wherein the substrate is positioned by a step portion formed on the upper surface of the top plate of the transfer mechanism.

8. A particle beam measuring device according to claim 6, wherein the attachment is detachably held by the transport mechanism from which the top plate has been removed.

9. A particle beam measuring device according to any one of claims 6 to 8, wherein the attachment has a fixing member that improves the repeatability of the fixed position relative to the transport mechanism.

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